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Sample records for casting impact properties

  1. Impact properties of zinc die cast alloys

    Energy Technology Data Exchange (ETDEWEB)

    Schrems, Karol K.; Dogan, Omer N.; Manahan, M.P. (MPM Technologies, Inc.); Goodwin, F.E. (ILZRO)

    2005-01-01

    Alloys 3, 5, AcuZinc 5, and ZA-8 were tested at five temperatures between -40 C and room temperature to determine impact properties. Izod impact energy data was obtained in accordance with ASTM D256. Unlike ASTM E23, these samples were tested with a milled notch in order to compare with plastic samples. In addition, flexural data was obtained for design use.

  2. Impact properties of the aircraft cast aluminium alloy Al-7Si0.6Mg (A357

    Directory of Open Access Journals (Sweden)

    Alexopoulos N.D.

    2010-06-01

    Full Text Available The impact mechanical properties of the widely used in the aeronautics A357 cast aluminum alloy were investigated by exploiting experiments on an instrumented Charpy impact testing machine. The evaluated impact properties for 25 different artificial aging heat treatment conditions were analyzed and discussed in conjunction with the respective tensile properties. Correlations are proposed to establish useful relationships between impact resistance and tensile strain energy density properties. The established correlations, which are well supported by the performed experiments, can be used to estimate the tensile ductility and toughness of the A357 cast aluminum alloy from the Charpy impact test. Performed fractographic analyses were supporting the physically arbitrary correlation between tensile strain energy density and impact resistance.

  3. Impact properties of the aircraft cast aluminium alloy Al-7Si0.6Mg (A357)

    Science.gov (United States)

    Alexopoulos, N. D.

    2010-06-01

    The impact mechanical properties of the widely used in the aeronautics A357 cast aluminum alloy were investigated by exploiting experiments on an instrumented Charpy impact testing machine. The evaluated impact properties for 25 different artificial aging heat treatment conditions were analyzed and discussed in conjunction with the respective tensile properties. Correlations are proposed to establish useful relationships between impact resistance and tensile strain energy density properties. The established correlations, which are well supported by the performed experiments, can be used to estimate the tensile ductility and toughness of the A357 cast aluminum alloy from the Charpy impact test. Performed fractographic analyses were supporting the physically arbitrary correlation between tensile strain energy density and impact resistance.

  4. Effect of iron-intermetallics and porosity on tensile and impact properties of aluminum-silicon-copper and aluminum-silicon-magnesium cast alloys

    Science.gov (United States)

    Ma, Zheyuan

    Aluminum-silicon (Al-Si) alloys are an important class of materials that constitute the majority of aluminum cast parts produced, due to their superior properties and excellent casting characteristics. Within this family of alloys, Al-Si-Cu and Al-Si-Mg cast alloys are frequently employed in automotive applications. The commercially popular 319 and 356 alloys, representing these two alloy systems, were selected for study in the present work, with the aim of investigating the effect of iron intermetallics and porosity on the alloy performance. This was carried out through a study of the tensile and impact properties, these being two of the important mechanical properties used in design calculations. Iron, through the precipitation of second phase intermetallic constituents, in particular the platelike beta-Al5FeSi phase, is harmful to the alloy properties. Likewise, gas- or shrinkage porosity in castings is also detrimental to the mechanical properties. By determining the optimum alloying, melt processing and solidification parameters (viz., Fe content, Sr modification and cooling rate) required to minimize the harmful effects of porosity and iron intermetallics, and studying their role on the fracture behavior, the fracture mechanism in the alloys could be determined. Castings were prepared from both industrial and experimental 319.2, B319.2 and A356.2 alloy melts, containing Fe levels of 0.2--1.0 wt%. Sr-modified (˜200 ppm) melts were also prepared for each alloy Fe level. The end-chilled refractory mold used provided directional solidification and a range of cooling rates (or dendrite arm spacings, DAS) within the same casting. Tensile and impact test samples machined from specimen blanks sectioned from the castings at various heights above the chill end provided DASs of 23--85mum. All samples were T6-heat-treated before testing. Tests were carried out employing Instron Universal and Instrumented Charpy testing machines. Optical microscopy, image analysis, SEM

  5. Microstructures and properties of aluminum die casting alloys

    Energy Technology Data Exchange (ETDEWEB)

    M. M. Makhlouf; D. Apelian; L. Wang

    1998-10-01

    This document provides descriptions of the microstructure of different aluminum die casting alloys and to relate the various microstructures to the alloy chemistry. It relates the microstructures of the alloys to their main engineering properties such as ultimate tensile strength, yield strength, elongation, fatigue life, impact resistance, wear resistance, hardness, thermal conductivity and electrical conductivity. Finally, it serves as a reference source for aluminum die casting alloys.

  6. Microstructure formation and properties of abrasion resistant cast steel

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    S. Parzych

    2010-01-01

    Full Text Available The so-called adamitic cast steels are characterised by a high abrasion resistance. These cast steels are of a pearlitic matrix with uniformly distributed hypereutectoid cementite precipitates. Apart from hypereutectoid cementite very often transformed ledeburite also occurs in the microstructure of these cast steels. Such cast steels contain chromium (app. 1 % and nickel (app. 0.5 % as alloy additions and sometimes their silicon content is increased. The presence of molybdenum is also permissible (app. 0.4 %. The basic problem in application of these steels for structural elements constitutes their insufficient crack resistance. An improvement of mechanical properties by changes of morphology of hypereutectoid cementite and transformed ledeburite precipitates by means of the heat treatment application was the aim of this study. G200CrNiMo4-3-3 cast steel was the investigated material. Changes in the morphology of hypereutectoid cementite and transformed ledeburite obtained due to the heat treatment are described in detail in the present paper. An influence of the microstructure changes on impact toughness of the investigated cast steel is presented. Investigations performed within this study will serve for the microstructure optimisation on account of functional qualities of this cast steel.

  7. Effect of melt treatment on microstructure and impact properties of Al–7Si and Al–7Si–2.5Cu cast alloys

    Indian Academy of Sciences (India)

    K G Basavakumar; P G Mukunda; M Chakraborty

    2007-10-01

    The microstructures and impact toughness of Al–7Si and Al–7Si–2.5Cu cast alloys were studied after various melt treatments like grain refinement and modification. The results indicate that combined grain refined and modified Al–7Si–2.5Cu alloys have microstructures consisting of uniformly distributed -Al grains, interdendritic network of fine eutectic silicon and fine CuAl2 particles in the interdendritic region. These alloys exhibited improved impact toughness in as cast condition when compared to those treated by individual addition of grain refiner or modifier. The improved impact toughness of Al–7Si–2.5Cu alloys are related to breakage of the large aluminum grains and uniform distribution of eutectic silicon and fine CuAl2 particles in the interdendritic region resulting from combined refinement and modification. This paper attempts to investigate the influence of microstructural changes in the Al–7Si and Al–7Si–2.5Cu cast alloys by grain refinement, modification and combined action of both on the impact toughness.

  8. Low temperature impact strength of heavy section ductile iron castings: effects of microstructure and chemical composition

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    C. Labrecque

    2011-02-01

    Full Text Available A foundry research project has been recently initiated at RTIT in order to better understand the fabrication of as-cast heavy section DI parts meeting high impact energy requirements at low temperatures. The experimental castings have the following dimensions 180 mm x 180 mm x 190 mm. The achieved as-cast Charpy impact strengths were as follows: 17 J (RT, 16 J (-20°C and 11 J (-40°C. The foundry process, the chemical composition and the microstructure of this experimental casting are compared to the ones of various examples in order to show the detrimental effects of residual elements, microshrinkage and microcarbide on the impact properties. Finally, quality index empirical models (based on casting chemical compositions are used to analyse the impact tests results. This paper illustrates that an adequate nodule count can contribute to reducing the detrimental effects of the residual elements and microsegregation.

  9. Impact properties of A356-T6 alloys

    Science.gov (United States)

    Shivkumar, S.; Wang, L.; Keller, C.

    1994-02-01

    The Charpy impact energy of A356 alloys has been measured. Instrumented Charpy impact tests have been conducted at 25,100,150, and 200 °C. The Charpy specimens were machined from plate castings ortapered cylindrical castings. The plates were produced in sand molds, and tapered cylinders were produced in water-cooled copper molds. Both unmodified and strontium-modified castings were tested. The results indicate that strontium modification improves the impact properties of sand and permanent mold castings. The impact energy increases with solution treatment time. Strontium modification reduces the solution treatment time for attaining a specific impact property level in the casting.

  10. Strain Rate Dependency of Bronze Metal Matrix Composite Mechanical Properties as a Function of Casting Technique

    Science.gov (United States)

    Brown, Lloyd; Joyce, Peter; Radice, Joshua; Gregorian, Dro; Gobble, Michael

    2012-07-01

    Strain rate dependency of mechanical properties of tungsten carbide (WC)-filled bronze castings fabricated by centrifugal and sedimentation-casting techniques are examined, in this study. Both casting techniques are an attempt to produce a functionally graded material with high wear resistance at a chosen surface. Potential applications of such materials include shaft bushings, electrical contact surfaces, and brake rotors. Knowledge of strain rate-dependent mechanical properties is recommended for predicting component response due to dynamic loading or impact events. A brief overview of the casting techniques for the materials considered in this study is followed by an explanation of the test matrix and testing techniques. Hardness testing, density measurement, and determination of the volume fraction of WC particles are performed throughout the castings using both image analysis and optical microscopy. The effects of particle filling on mechanical properties are first evaluated through a microhardness survey of the castings. The volume fraction of WC particles is validated using a thorough density survey and a rule-of-mixtures model. Split Hopkinson Pressure Bar (SHPB) testing of various volume fraction specimens is conducted to determine strain dependence of mechanical properties and to compare the process-property relationships between the two casting techniques. The baseline performances of C95400 bronze are provided for comparison. The results show that the addition of WC particles improves microhardness significantly for the centrifugally cast specimens, and, to a lesser extent, in the sedimentation-cast specimens, largely because the WC particles are more concentrated as a result of the centrifugal-casting process. Both metal matrix composites (MMCs) demonstrate strain rate dependency, with sedimentation casting having a greater, but variable, effects on material response. This difference is attributed to legacy effects from the casting process, namely

  11. Effect of Some Parameters on the Cast Component Properties in Hot Chamber Die Casting

    Science.gov (United States)

    Singh, Rupinder; Singh, Harvir

    2016-04-01

    Hot chamber die casting process is designed to achieve high dimensional accuracy for small products by forcing molten metal under high pressure into reusable moulds, called dies. The present research work is aimed at study of some parameters (as a case study of spring adjuster) on cast component properties in hot chamber die casting process. Three controllable factors of the hot chamber die casting process (namely: pressure at second phase, metal pouring temperature and die opening time) were studied at three levels each by Taguchi's parametric approach and single-response optimization was conducted to identify the main factors controlling surface hardness, dimensional accuracy and weight of the casting. Castings were produced using aluminium alloy, at recommended parameters through hot chamber die casting process. Analysis shows that in hot chamber die casting process the percentage contribution of second phase pressure, die opening time, metal pouring temperature for surface hardness is 82.48, 9.24 and 6.78 % respectively. While in the case of weight of cast component the contribution of second phase pressure is 94.03 %, followed by metal pouring temperature and die opening time (4.58 and 0.35 % respectively). Further for dimensional accuracy contribution of die opening time is 76.97 %, metal pouring temperature is 20.05 % and second phase pressure is 1.56 %. Confirmation experiments were conducted at an optimal condition showed that the surface hardness, dimensional accuracy and weight of the castings were improved significantly.

  12. Properties shaping and repair of selected types of cast iron

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    J. Szajnar

    2007-04-01

    Full Text Available The paper presents research results of twofold use of TIG - Tungsten Inert Gas also known as GTA - Gas Tungsten Arc. First is surfacing by welding on cold and hot-cold to repair chromium cast iron with chromium content about 15%. Second is remelting with electric arc of selected gray (with pearlitic matrix and ductile (with ferritic-pearlitic matrix cast iron. Repair of cast iron elements was realized in order to cut out a casting defects. Defects decrease a usability of castings for constructional application and increase a manufacturing costs. Application of surface heat treatment guarantees mechanical properties i.e. hardness and wear resistance improvement. The result of investigations show possibility of castings repair by put on defects a good quality padding welds, which have comparable properties with base material. Use of electric arc surface heat treatment resulted in increase of hardness and wear resistance, which was measured on the basis of ASTM G 65 - 00 standard.

  13. Mechanical properties of homogenized twin-roll cast and conventionally cast AZ31 magnesium alloys

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    Mariia Zimina

    2015-02-01

    Full Text Available The improvement of mechanical properties of magnesium alloys nowadays is very important, because of the variety of industrial applications. For this goal, the number of casting techniques and further treatments were developed. Among the continuous casting techniques, which allow producing long strips of the alloys, is twin-roll casting. Using this process one can get the magnesium alloy with finest microstructure and higher specific strength. In this paper the comparison of tensile properties of conventionally cast and twin-roll cast AZ31 magnesium alloys was made. Tensile tests were carried out with constant strain rate 10-3 s-1 at temperatures ranging from 100 to 300 °C. Both materials were tested in as-cast state and after homogenization treatment at 450 °C for 10 hours. The investigation showed that there are no significant changes in ductility of AZ31 conventionally cast alloy even after heat treatment, while the ductility of twin-roll cast alloy increases.

  14. Wear Property of Cast Steel Wheel Material in Rail Truck

    Institute of Scientific and Technical Information of China (English)

    MI Guo-fa; LIU Yan-lei; ZHANG Bin; FU Xiu-qin; ZHANG Hong; SONG Guo-xiang

    2009-01-01

    Wear property of material plays a key role in the service time of workpiece.A major objective in the development of new wheel materials is to improve the wear performance.The wear property of B and B+ grade cast steel materials was reported.The results showed that B+ grade cast steel material exhibited better wear property than the B grade material.Carbon content related to the hardness match was the principal factor affecting the wear properties.

  15. SYSTEMATIC AND DYNAMIC PROPER-TIES OF CASTING HOT SPOT

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The variation of casting hot spot with proceeding of solidification and components of casting-mold system is studied by the technique of numerical simulation of solidification.The result shows that the thickest part of casting is not exactly the last part of solidification in the casting, while the last part of solidification is not exactly casting hot spot at the early stage of solidification.The location, size, shape and number of casting hot spot change with geomitric, physical and technological factors of the casting-mold system such as thickness of the casting secondary wall and with the passage of time in the course of the solidification.The former is known as the systematic property of hot spot and the latter, dynamic property.Only when the properties of hot spot are grasped completely and accurately, can it be fed more effectively.By doing so, not only sound castings can be obtained, but also riser efficiency can be improved.

  16. Effect of molybdenum, vanadium, boron on mechanical properties of high chromium white cast iron in as-cast condition

    Science.gov (United States)

    Nurjaman, F.; Sumardi, S.; Shofi, A.; Aryati, M.; Suharno, B.

    2016-02-01

    In this experiment, the effect of the addition carbide forming elements on high chromium white cast iron, such as molybdenum, vanadium and boron on its mechanical properties and microstructure was investigated. The high chromium white cast iron was produced by casting process and formed in 50 mm size of grinding balls with several compositions. Characterization of these grinding balls was conducted by using some testing methods, such as: chemical and microstructure analysis, hardness, and impact test. From the results, the addition of molybdenum, vanadium, and boron on high chromium white cast iron provided a significant improvement on its hardness, but reduced its toughness. Molybdenum induced fully austenitic matrix and Mo2C formation among eutectic M7C3 carbide. Vanadium was dissolved in the matrix and carbide. While boron was played a role to form fine eutectic carbide. Grinding balls with 1.89 C-13.1 Cr-1.32 Mo-1.36 V-0.00051 B in as-cast condition had the highest hardness, which was caused by finer structure of eutectic carbide, needle like structure (upper bainite) matrix, and martensite on its carbide boundary.

  17. Unnotched Charpy Impact Energy Transition Behavior of Austempered Engineering Grade Ductile Iron Castings

    Science.gov (United States)

    Kisakurek, Sukru Ergin; Ozel, Ahmet

    2014-04-01

    Unnotched Charpy impact energy transition behavior of five different engineering grade ductile iron castings, as specified by EN 1563 Standards, were examined in as-cast, as well as in austempered states. ADIs were produced with the maximum impact energy values permissible for the grades. Austempering treatment detrimented the sub-zero impact properties of the ferritic castings, but considerably enhanced those of the pearlitic-ferritic irons. The impact energy transition behavior of the austempered states of all the grades examined were noted to be determined by the progressive transformation of the unavoidable carbon-unsaturated and untransformed regions of the austenite remaining in the matrix of the austempered ductile iron to martensite with decreasing temperature.

  18. Structure and mechanical properties of vermicular cast iron in cylinder head casting

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    E. Guzik

    2009-01-01

    Full Text Available The paper discusses the problem of grain density and ferrite content in microstructure of vermicular graphite iron cast in bars of different section diameters and cylinder head casting. The experimental results regarding the section effect demonstrate that the nodule count, grain density and ferrite content are all function of the cast bar diameter in this particular case ranging from 0.6 to 8.0 cm and microstructure and mechanical properties in the cylinder head. The nodule count (or grain density has been reported to increase, while ferrite content was decreasing with decreasing casting diameter. The density number of the grains Nv has been related (by regression analysis to the undercooling degree

  19. Structure and properties of stir-cast zinc alloys

    Energy Technology Data Exchange (ETDEWEB)

    LeHuy, H.; Blain J.; Masounave, J.; Bata, G.L. (Industrial Materials Research Institute, Boucherville, P.Q. (Canada))

    Stir casting (or rheocasting) of ZA-27 zinc alloys was investigated experimentally. By vigorously agitating the alloys during cooling, the dendrites that were forming were fragmented giving a unique structure composed of spherical and rosette shaped particles suspended in the remaining liquid. Under high shear rates ({center dot}{gamma} = 300s{sup {minus}1} or more) the slurries with primary particle concentrations as high as 60% displayed viscosities as low as 20 poises and could easily be casted. The effects of processing variables such as shearing and cooling rates and casting temperatures were studied. Their relative importance on the rheological and microstructural behavior of the stir cast alloys are discussed. Results from viscosity measurements on slurries show that non-dendritical ZA-27 alloys obey a power law fluid model. Finally, results from mechanical and compressive studies carried out on solidified slurries are discussed and compared to conventional casted and wrought alloy properties.

  20. Hypereutectoid cementite morphology and mechanical properties of Cr-Ni-Mo cast steel

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    E. Rożniata

    2006-04-01

    Full Text Available Purpose: The paper presents evaluation of the influence of grain normalization (refinement as a result of repeated austenitizing, cooling rate after repeated austenitizing on the morphology of hypereutectoid cementite and fracture toughness of G200CrMoNi4-6-3 cast steel. Moreover, the elimination of hypereutectoid cementite in structure of Widmannstätten type precipitates from the structure of investigated cast steel has been undertaken.Design/methodology/approach: Basic research of G200CrMoNi4-6-3 cast steel included metallographic analysis and fracture toughness research (impact strength, stress intensity factor KIc. The heat treatment has been planned on the basis of CCT diagram prepared for that cast steel.Findings: Heat treatment of investigated cast steel allows to refine the grain and eliminate from it’s structure the hypereutectoid cementite in structure of Widmannstätten type. At very low cooling rate the precipitates of hypereutectoid cementite become partially coagulated. The study of the influence of cooling rate on the mechanical properties of G200CrMoNi4-6-3 cast steel had proven that elimination of hypereutectoid cementite in structure of Widmannstätten type from the investigated cast steel structure to small degree increases it’s fracture toughness.Research limitations/implications: Research financed by the Ministry of Scientific Research and Information Technology, grant No. 3 T08B 057 29.Practical implications: G200CrMoNi4-6-3 cast steel of ledeburite class is used mainly for rolls production. Any data related to the structure and mechanical properties of that cast steel are precious for the manufacturers and users of the mill rolls.Originality/value: The new heat treatment of G200CrMoNi4-6-3 cast steel.

  1. The impact of breaks during foundry work of the pressure casting machine on casting quality

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    S. Borkowski

    2010-10-01

    Full Text Available The result in the appearance of the technical object damage are its failures, which are considered as the most important causes of productivity loss in the technical objects. The article introduces main types of losses resulting from the downtimes of a casting machine. The time impact analysis of the font mould failure and the remaining time of the machine's failures on the castings quality was conducted. The failure time structure of the font mould and other failures of the machine was presented.

  2. Effect of Bi on graphite morphology and mechanical properties of heavy section ductile cast iron

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    Song Liang

    2014-03-01

    Full Text Available To improve the mechanical properties of heavy section ductile cast iron, bismuth (Bi was introduced into the iron. Five castings with different Bi content from 0 to 0.014 wt.% were prepared; and four positions in the casting from the edge to the center, with different solidification cooling rates, were chosen for microstructure observation and mechanical properties test. The effect of the Bi content on the graphite morphology and mechanical properties of heavy section ductile cast iron were investigated. Results show that the tensile strength, elongation and impact toughness at different positions in the five castings decrease with a decrease in cooling rate. With an increase in Bi content, the graphite morphology and the mechanical properties at the same position are improved, and the improvement of mechanical properties is obvious when the Bi content is no higher than 0.011wt.%. But when the Bi content is further increased to 0.014wt.%, the improvement of mechanical properties is not obvious due to the increase of chunky graphite number and the aggregation of chunky graphite. With an increase in Bi content, the tensile fracture mechanism is changed from brittle to mixture ductile-brittle fracture.

  3. Effects of Alloying Elements on the Microstructures and Mechanical Properties of Heavy Section Ductile Cast Iron

    Institute of Scientific and Technical Information of China (English)

    G.S. Cho; K.H. Choe; K.W. Lee; A.Ikenaga

    2007-01-01

    The effects of alloying elements on the as-cast microstructures and mechanical properties of heavy section ductile cast iron were investigated to develop press die material having high strength and high ductility.Measurements of ultimate tensile strength, 0.2% proof strength, elongation and unnotched Charpy impact energy are presented as a function of alloy amounts within 0.25 to 0.75 wt pct range. Hardness is measured on the broken tensile specimens. The small additions of Mo, Cu, Ni and Cr changed the as-cast mechanical properties owing to the different as-cast matrix microstructures. The ferrite matrix of Mo and Ni alloyed cast iron exhibits Iow strength and hardness as well as high elongation and impact energy. The increase in Mo and Ni contents developed some fractions of pearlite structures near the austenite eutectic cell boundaries, which caused the elongation and impact energy to drop in a small range. Adding Cu and Cr elements rapidly changed the ferrite matrix into pearlite matrix, so strength and hardness were significantly increased. As more Mo and Cr were added. the size and fraction of primary carbides in the eutectic cell boundaries increased through the segregation of these elements into the intercellular boundaries.

  4. Microstructure and mechanical properties of a new type of austempered boron alloyed high silicon cast steel

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    Chen Xiang

    2013-05-01

    Full Text Available In the present paper, a new type of austempered boron alloyed high silicon cast steel has been developed, and its microstructures and mechanical properties at different temperatures were investigated. The experimental results indicate that the boron alloyed high silicon cast steel comprises a dendritic matrix and interdendritic eutectic borides in as-cast condition. The dendritic matrix is made up of pearlite, ferrite, and the interdendritic eutectic boride is with a chemical formula of M2B (M represents Fe, Cr, Mn or Mo which is much like that of carbide in high chromium white cast iron. Pure ausferrite structure that consists of bainitic ferrite and retained austenite can be obtained in the matrix by austempering treatment to the cast steel. No carbides precipitate in the ausferrite structure and the morphology of borides remains almost unchanged after austempering treatments. Secondary boride particles precipitate during the course of austenitizing. The hardness and tensile strength of the austempered cast steel decrease with the increase of the austempering temperature, from 250 篊 to 400 篊. The impact toughness is 4-11 J昪m-2 at room temperature and the impact fracture fractogragh indicates that the fracture is caused by the brittle fracture of the borides.

  5. Solidification, processing and properties of ductile cast iron

    DEFF Research Database (Denmark)

    Tiedje, Niels Skat

    2010-01-01

    Ductile cast iron has been an important engineering material in the past 50 years. In that time, it has evolved from a complicated material that required the foundry metallurgist's highest skill and strict process control to being a commonly used material that can easily be produced with modern...... of the latest years of research indicate that ductile cast iron in the future will become a highly engineered material in which strict control of a range of alloy elements combined with intelligent design and highly advanced processing allows us to target properties to specific applications to a much higher...... and to illustrate how ductile iron's properties are optimised, the essentials of heat treatment are described too. It is the hope that researchers will find a comprehensive treatment of ductile cast iron metallurgy and that engineers and designers will be presented with the latest information on, and references to...

  6. Microstructure and properties of cast iron after laser surface hardening

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    Stanislav

    2013-12-01

    Full Text Available Laser surface hardening of cast iron is not trivial due to the material’s heterogeneity and coarse-grained microstructure, particularly in massive castings. Despite that, hardening of heavy moulds for automotive industry is in high demand. The present paper summarises the findings collected over several years of study of materials structure and surface properties. Phase transformations in the vicinity of graphite are described using examples from production of body parts in automotive industry. The description relates to formation of martensite and carbide-based phases, which leads to hardness values above 65 HRC and to excellent abrasion resistance.

  7. Microstructure and Property of Hypereutectic High Chromium Cast Iron Prepared by Slope Cooling Body-Centrifugal Casting Method

    Institute of Scientific and Technical Information of China (English)

    Zhifu HUANG; Jiandong XING; Anfeng ZHANG

    2006-01-01

    In this paper, the ring-type ingot of hypereutectic high Cr cast iron was obtained by slope cooling bodycentrifugal casting method (SC-CCM), and its microstructure and impact toughness were investigated, respectively. The results indicated that, first, the primary carbides in the microstructure are prominently finer than those in the hypereutectic high Cr cast iron prepared by conventional casting method. Second, in the ring-type ingot, the primary carbides near radial outer field are finer than those near radial inner field; furthermore, there is dividing field in the microstructure. Finally, the impact toughness values of the specimens impacted on the radial outer face and on the radial inner face are improved respectively about 36% and 138%more than that of the hypereutectic high Cr one prepared by conventional casting method.

  8. Effects of Silicon on Mechanical Properties and Fracture Toughness of Heavy-Section Ductile Cast Iron

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    Liang Song

    2015-01-01

    Full Text Available The effects of silicon (Si on the mechanical properties and fracture toughness of heavy-section ductile cast iron were investigated to develop material for spent-nuclear-fuel containers. Two castings with different Si contents of 1.78 wt.% and 2.74 wt.% were prepared. Four positions in the castings from the edge to the center, with different solidification cooling rates, were chosen for microstructure observation and mechanical properties’ testing. Results show that the tensile strength, elongation, impact toughness and fracture toughness at different positions of the two castings decrease with the decrease in cooling rate. With an increase in Si content, the graphite morphology and the mechanical properties at the same position deteriorate. Decreasing cooling rate changes the impact fracture morphology from a mixed ductile-brittle fracture to a brittle fracture. The fracture morphology of fracture toughness is changed from ductile to brittle fracture. When the Si content exceeds 1.78 wt.%, the impact and fracture toughness fracture morphology transforms from ductile to brittle fracture. The in-situ scanning electronic microscope (SEM tensile experiments were first used to observe the dynamic tensile process. The influence of the vermicular and temper graphite on fracture formation of heavy section ductile iron was investigated.

  9. Influence of isothermal quenching of LAMC CrMnSi cast steel on impact toughness

    Institute of Scientific and Technical Information of China (English)

    JIN Bao-shi; HUANG Zhi-qiu; SHEN Da-dong

    2005-01-01

    The influence of isothermal quenching process of low-alloy and medium carbon (LAMC) CrMnSi cast steel on the impact toughness was investigated. The microstructure and mechanical property of LAMC CrMnSi cast steel were analyzed by the laser optical modulator, the scanning electron microscopy, the energy dispersive spectrometer, the hardness and impact tests. The experimental results show that the dual phases of bainite and residual austenite can be obtained by the severity isothermal quenching, the fractographies of specimens change from quasi-cleavage to dimple at 310 ℃ for 60 min, the impact toughness for specimens at the room temperature isothermally achieves 130 J/cm2, meantime and its hardness is more than 45(HRC).

  10. Processing Technology and Mechanical Properties of Die-Cast Magnesium Alloy AZ91D

    Institute of Scientific and Technical Information of China (English)

    LIU Yan'gai(刘艳改); LIU Wenhui(刘文辉); XIONG Shoumei(熊守美); LIU Baicheng(柳百成); Wang Gang (王罡); MATSUMOTO Yoshihide; MURAKAMI Masayuki

    2004-01-01

    The mechanical properties of magnesium die-casting components can be improved with improved die-casting processing technology. An orthogonal experiment with four factors and three levels (Lq, 34) was used to evaluate the effect of various die-casting processing parameters on the quality and mechanical properties of an AZ91D magnesium alloy cylinder head cover component. The results show that the injection speed and casting and die temperatures all influence the component quality, with the influence of the casting pressure being the smallest. The injection speed and casting pressure are the two most important factors influencing the tensile strength. The best die-casting parameters for the magnesium alloy cylinder head cover component were determined to be a casting temperature of 660℃, a die temperature of 200℃, an injection speed of 70 ms(1, and a casting pressure of 65 MPa. The porosity is one of the most important parameters influencing the casting strength.

  11. Fatigue properties of ductile cast iron containing chunky graphite

    Energy Technology Data Exchange (ETDEWEB)

    Ferro, P., E-mail: ferro@gest.unipd.it [Department of Management and Engineering, University of Padova, Stradella S. Nicola 3, I-36100 Vicenza (Italy); Lazzarin, P.; Berto, F. [Department of Management and Engineering, University of Padova, Stradella S. Nicola 3, I-36100 Vicenza (Italy)

    2012-09-30

    Highlights: Black-Right-Pointing-Pointer Experimental determination of high cycle fatigue properties of EN-GJS-400. Black-Right-Pointing-Pointer Evaluation of the influence of chunky graphite morphology on fatigue life. Black-Right-Pointing-Pointer Metallurgical analysis and microstructural parameters determination. Black-Right-Pointing-Pointer Nodule counting and nodularity rating. - Abstract: This work deals with experimental determination of high cycle fatigue properties of EN-GJS-400 ductile cast iron containing chunky graphite. Constant amplitude axial tests were performed at room temperature under a nominal load ratio R = 0. In order to evaluate the influence of chunky graphite morphology on fatigue life, fatigue tests were carried out also on a second set of specimens without this microstructural defect. All samples were taken from the core of a large casting component. Metallurgical analyses were performed on all the samples and some important microstructural parameters (nodule count and nodularity rating, among others) were measured and compared. It was found that a mean content of 40% of chunky graphite in the microstructure (with respect to total graphite content) does not influence significantly the fatigue strength properties of the analysed cast iron. Such result was attributed to the presence of microporosity detected on the surface fracture of the specimens by means of electron scanning microscope.

  12. Effect of quenching temperature on structure and properties of centrifugal casting high speed steel roll

    Directory of Open Access Journals (Sweden)

    Fu Hanguang

    2009-02-01

    Full Text Available The critical points and time-temperature-transformation (TTT curves of the isothermal transformation diagrams for a high-speed steel casting on a horizontal centrifugal casting machine had been determined experimentally in the study. The effects of quenching temperature on the microstructures and properties of centrifugal casting high speed steel (HSS roll has been investigated using scanning electron microscopy (SEM, light optical microscopy (LOM and X-ray diffraction (XRD as well as using tensile, impact, and hardness tests. The results show that the HSS roll has excellent hardenability and its matrix structure can be transformed into the martensite after being quenched in the sodium silicate solution. The retained austenite in the quenching structure increases and the hardness decreases when the quenching temperature exceeds 1,040℃. The tensile strength and impact toughness of HSS roll increase once the quenching temperature is raised from 980℃ to 1,040℃. However, the tensile strength and impact toughness have no signifi cant change when the quenching temperature exceeds 1,040℃. The HSS roll quenched at 1,040℃ exhibits excellent comprehensive mechanical properties.

  13. Effect of quenching temperature on structure and properties of centrifugal casting high speed steel roll

    Institute of Scientific and Technical Information of China (English)

    Fu Hanguang; Cheng Xiaole; Du Zhongze; Lei Yingping; Feng Zhenjun

    2009-01-01

    The critical points and time-temperature-transformation (TTT) curves of the isothermal transformation diagrams for a high-speed steel casting on a horizontal centrifugal casting machine had been determined experimentally in the study. The effects of quenching temperature on the microstructures and properties of centrifugal casting high speed steel (HSS) roll has been investigated using scanning electron microscopy (SEM), light optical microscopy (LOM) and X-ray diffraction (XRD) as well as using tensile, impact, and hardness tests. The results show that the HSS roll has excellent hardenability and its matrix structure can be transformed into the martensite after being quenched in the sodium silicate solution. The retained austenite in the quenching structure increases and the hardness decreases when the quenching temperature exceeds 1,040℃. The tensile strength and impact toughness of HSS roll increase once the quenching temperature is raised from 980℃ to 1,040℃. However, the tensile strength and impact toughness have no significant change when the quenching temperature exceeds 1,040℃. The HSS roll quenched at 1,040℃ exhibits excellent comprehensive mechanical properties.

  14. A study of microstructure and properties of cast Fe-10Cr-1.5B alloy

    Directory of Open Access Journals (Sweden)

    Zhang Haibin

    2014-05-01

    Full Text Available In the present study, the microstructure and mechanical properties of cast Fe-10Cr-1.5B (FCB alloy after different heat treatments were studied. The results showed that the as-cast microstructure of FCB alloy consists of ?Fe, M(M=Cr, Fe, Mn2(B, C and M(M=Cr, Fe, Mn7(C, B3 type borocarbides, and small amounts of pearlite and austenite. After oil quenching treatment, metal matrix transformed into the martensite from the mixture of martensite, pearlite and austenite. There are many M(M=Cr,Fe,Mn23(C,B6 type borocarbide precipitates in the metal matrix, and eutectic borocarbide appears with an apparent disconnection and isolated phenomenon. When the quenching temperature reaches 1,050 oC, the hardness of FCB alloy is the highest, but the change of quenching temperature has no obvious effect on impact toughness of FCB alloy. After tempering, the eutectic microstructure of FCB alloy appears with a "two links" trend. With the increase of tempering temperature, the hardness of FCB alloy decreases gradually and impact toughness increases gradually. Cast FCB alloy oil-quenched from 1,050 oC and tempered from 200 oC has excellent combined properties; its hardness and impact toughness are 61.5 HRC and 8.8 J.m-2 respectively.

  15. Microstructure, Impact Fatigue Resistance and Impact Wear Resistance of Wear Resistant Low Cr-Si Cast Iron

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A great amount of iron and steel has been consumed in impact wear resistance parts such as grinding balls and lining plates in tube mills. Under this working conditions, the failure of wear resistant white irons is generally caused by fatigue spalling. The martensitic high chromium cast iron (WCr=15 %) has good wear resistance, but its cost is higher. The impact wear resistance of low chromium cast iron sometimes is not good. In the present paper ,a new wear resistant material-low Cr-Si cast iron was introduced. The influence of microstructure of cast iron on impact fatigue resistance and impact wear resistance was discussed. The ball-on-ball impact fatigue test, the high stress impact wear test and the field test of the grinding balls have been carried out. The results showed that the impact fatigue resistance (IFR) and impact wear resistance (IWR) of low Cr-Si cast iron are superior to typical low chromium cast irons and close to the martensitic high chromium cast iron. The main reasons are: ① The as-cast matrix of the low Cr-Si cast iron with stress released is pearlite with better plasticity and toughness; ② The high Si content improves the morphology of eutectic carbide, and has no secondary carbide resulting in less crack sources. All these factors are beneficial to the improvement of impact fatigue spalling resistance and impact wear resistance.

  16. Impact characteristics of austempered spheroidal graphite cast steel. Austemper kyujo kokuen chuko no shogeki tokusei

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, T.; Tada, S.; Abe, T. (Government Industrial Research Institute, Tohoku, Sendai (Japan))

    1993-08-25

    Austempered ductile cast iron (ADI) has excellent mechanical properties both in strength and toughness, but the Young's modulus of ADI is lower than that of steel because ADI contains much graphite. In order to obtain better mechanical properties than ADI, spheroidal graphite cast steel containing less graphite by volume was austempered. The Young's modulus of austempered spheroidal graphite cast steel (AGS) was 200 GPa, which was comparable to steel. The retained austenite volume of the sample containing 2.4% Si varied with the austempering conditions, but that of the sample containing 1.4% Si decreased in a shorter austempered time. As a result, it was found that Si affects stability of the retained austenite. Charpy impact value increased with increasing the retained austenite volume when the volume was above 15%. The impact value of AGS with 40% retained austenite was over twice as large as that of ADI austempered under the same conditions. 21 refs., 8 figs., 1 tab.

  17. ON MODELLING OF MICROSTRUCTURE FORMATION, LOCAL MECHANICAL PROPERTIES AND STRESS – STRAIN DEVELOPMENT IN ALUMINIUM CASTINGS

    DEFF Research Database (Denmark)

    Svensson, Ingvar; Seifeddine, Salem; Kotas, Petr

    2009-01-01

    inherently affects the component’s properties depending on design, metallurgy and casting method. The wall thickness influences the coarseness of the microstructure and the material will have properties depending on the local metallurgical and thermal histories. This is independent on the material, i.......e. whether the casting is based on cast iron- or aluminium-alloys. The distribution of local properties in a casting might vary substantially which makes it difficult to optimize the casting with good accuracy. Often, mechanical simulations of the load situation are based on the assumption that the cast...... product has constant material properties throughout the entire casting. Thus, if the microstructure is determined or predicted at a given point, it gives the possibility to calculate the local material behaviour more realistically. The paper shows modelling and simulation of microstructure formation...

  18. Microstructure and Dynamic Failure Properties of Freeze-Cast Materials for Thermobaric Warhead Cases

    Science.gov (United States)

    2012-12-01

    LIST OF FIGURES Figure 1. Freeze cast process: slurry preparation, solidification, sublimation and sintering (From Ref 6...the process can be divided into four steps, illustrated in Figure 1. 6 Figure 1. Freeze cast process: slurry preparation, solidification...DYNAMIC FAILURE PROPERTIES OF FREEZE- CAST MATERIALS FOR THERMOBARIC WARHEAD CASES by Yi Ming Tan December 2012 Thesis Advisor: Joseph

  19. Modelling of Filling, Microstructure Formation, Local Mechanical Properties and Stress – Strain Development in High-Pressure Die Cast Aluminium Castings

    DEFF Research Database (Denmark)

    Kotas, Petr; Hattel, Jesper Henri; Thorborg, Jesper

    2009-01-01

    inherently affects the component’s properties depending on design, metallurgy and casting technique. The wall thickness influences the coarseness of the microstructure and the material will have properties depending on the local metallurgical and thermal histories. This is independent on the material, i.......e. whether the casting is based on cast iron- or aluminium-alloys. The distribution of local properties in a casting might vary substantially which makes it complex to optimize the casting with good accuracy. Often, mechanical simulations of the load situation are based on the assumption that the cast...... product has constant material properties throughout the entire casting. Thus, if the microstructure is determined or predicted at a given point, it gives the possibility to calculate the local material behavior more realistically. In the present work, a test case of a complex high-pressure die cast part...

  20. Influence of a matrix on properties of mottled cast iron applied for mill rolls

    Directory of Open Access Journals (Sweden)

    J. Krawczyk

    2010-07-01

    Full Text Available Mill rolls are ones of the most expensive tools applied in plastic working processes and have to satisfy several criteria, which allow them to be used. Cast iron mill rolls, due to their fracture toughness and tribological properties, are the most often applied at hot-rolling in the last rolling stands. This results from the smallest dynamic loads of such rolling stands and the decisive influence of the surface quality of these tools on the surface quality of the rolled product. An improper microstructure of rolls can lead to their premature wearing, e.g. broken flanges, pivots twisting off etc. By means of the heat treatment the matrix microstructure and morphology of carbide precipitationscan be modified and this in-turn can influence cast iron properties.Determination of the influence of microstructure changes, caused by the heat treatment, on the properties of EN-GJN-HV300 low-alloycast iron, after its modification and spheroidization – is the aim of the present paper. Those changes are based on the formation pearlitic or bainitic matrices at the similar morphology of graphite and ledeburitic cementite precipitations. The performed investigations should enable designing the heat treatment of cast iron metallurgical rolls in such a way as to obtain the optimal microstructures for functional parameters of these type of tools. The influence of changing the pearlitic matrix into the bainitic one on such properties as: hardness, impact strength, tensile strength, creep limit, bending strength and a stress intensity factor KIc was investigated in this study. Samples for testing, the listed above mechanical properties, were taken from an industrial casting with care to have pieces of very similar crystallization conditions.

  1. Effect of heat treatment on microstructure and mechanical properties of high boron white cast iron

    Energy Technology Data Exchange (ETDEWEB)

    Chen Xiang, E-mail: xchen@mail.tsinghua.edu.cn [Key Laboratory for Advanced Materials Processing Technology, Ministry of Education, Department of Mechanical Engineering, Tsinghua University, Beijing 100084 (China); Li Yanxiang [Key Laboratory for Advanced Materials Processing Technology, Ministry of Education, Department of Mechanical Engineering, Tsinghua University, Beijing 100084 (China)

    2010-12-15

    Research highlights: {yields} The iron comprises a fine pearlite and M{sub 2}B boride at as-cast condition. {yields} Tempered at a higher temperature, some particles precipitated in the matrix. {yields} The secondary precipitates have a crystal structure of M{sub 23}(B,C){sub 6}. {yields} Optimum structure is obtained when tempered at 400 deg. C. - Abstract: The effect of different tempering temperatures on the microstructure and mechanical properties of high boron white cast iron after air quenching was studied. The experimental results indicate that the high boron white cast iron comprises a dendritic matrix and interdendritic boride M{sub 2}B that distributed in the form of continuous network and the matrix is composed of fine pearlite at as-cast condition. After austenitising at 920 deg. C and air quenching, the matrix of high boron cast iron is changed from pearlite to lath-type martensite, and the morphology of boride is still kept in the form of continuous network. After tempered at 200 deg. C or a higher temperature, a secondary precipitation with a size of tens of nanometers is found in the matrix, and the size and the amount of this secondary precipitation increase with the increasing of tempering temperature. TEM analysis shows that the secondary precipitates have a crystal structure of M{sub 23}(B,C){sub 6}. With the increasing of tempering temperature after air quenching, the hardness decreases, and the impact toughness firstly increases to a maximum value and then decreases. The optimum structure that has a combination of high hardness and high impact toughness can be obtained when the tempering temperature is lower than 400 deg. C.

  2. Life cycle assessment as a method of limitation of a negative environment impact of castings

    Directory of Open Access Journals (Sweden)

    M. Holtzer

    2011-07-01

    Full Text Available Casting production constitutes environmental problems going far beyond the foundry plant area. Applying a notion of the life cycle the input (suppliers side and output factors (clients side can be identified. The foundry plant activities for the environment hazard mitigation can be situated on various stages of the casting life cycle. The environment impact of motorisation castings made of different materials – during the whole life cycle of castings – are discussed in the paper. It starts from the charge material production, then follows via the casting process, car assembly, car exploitation and ends at the car breaking up for scrap.

  3. Microstructure and Property of High Carbonic-Chromium Cast Steel with Different Hot Deformation Ratio

    Institute of Scientific and Technical Information of China (English)

    XU Tao; WANG Jiu-liang; ZHANG Run-jun; CHAO Guo-hua; LIU Jian-hua

    2004-01-01

    The microstructure and properties of high carbonic-chromium cast steel subjected to different hot deformation ratios were studied. The experimental results show that the microstructure and properties of high carbonic-chromium cast steel are obviously improved after hot deformation, and the best mechanical properties of the cast steel can be obtained under hot deformation ratio of 40 %-50 %, which leads to the morphology change of eutectic carbide and the precipitation of granular carbides.

  4. Effect of Manganese on the Mechanical Properties of Welded As-Cast Aluminium Joint

    Directory of Open Access Journals (Sweden)

    Isiaka Oluwole OLADELE

    2013-11-01

    Full Text Available The effects of manganese on the mechanical properties of welded and un-weld as-cast 6063 aluminium alloy has been studied. Alloys of varying percentage of manganese from 0.019 to 0.24 were sand cast. A wooden pattern of dimensions 200×100×100mm was used, the aluminium (500g was charged into an induction furnace and heated to 750°C for 15 minutes, this was followed by the addition of weighed powdered manganese, stirred and heated at the same temperature for another 5 minutes and thereafter poured into the already prepared sand mould at a temperature of 690°C. The as-cast aluminium samples, were sectioned into two equal parts of 45mm each using power hack saw; a weld groove was created between the sides of the samples using an electric hand grinding machine, the groove served as the path along which the filler metal was deposited on the aluminium, a single v butt joint was produced from each sample and Metal Inert Gas Welding process was carried out to produce the required joint design. The different cast samples were machined to the different test pieces after which they were assessed to determine their mechanical properties (impact, hardness (welded joint and heat affected zone and tensile tests. The microstructures of the welded samples were also studied. From the results, it was observed that Sample F, which has 0.172% Mn, has the best hardness and impact strength while sample C with 0.160% Mn has the highest ultimate tensile strength.

  5. Effect of Heat Treatment on Mechanical Property of High Cr-W Cast Iron

    Institute of Scientific and Technical Information of China (English)

    Liu Jianping; Li Lixia

    2007-01-01

    The microstructure of high Cr-W cast iron after heat treatment were analyzed, and the effect of various heat treatment temperature and time on mechanical properties of high Cr-W cast iron were studied, and the best process parameter of heat treatment was provided in this paper. The results show that the heat treatment can improve the mechanical property of high Cr-W cast iron, and higher synthetic mechanical property of high Cr-W cast iron can be obtained when treated with normalization at 980℃ for 2h and tempered at 400℃ for 2h.

  6. Microstructure formation and properties of abrasion resistant cast steel

    OpenAIRE

    S. Parzych; Krawczyk, J.

    2010-01-01

    The so-called adamitic cast steels are characterised by a high abrasion resistance. These cast steels are of a pearlitic matrix with uniformly distributed hypereutectoid cementite precipitates. Apart from hypereutectoid cementite very often transformed ledeburite also occurs in the microstructure of these cast steels. Such cast steels contain chromium (app. 1 %) and nickel (app. 0.5 %) as alloy additions and sometimes their silicon content is increased. The presence of molybdenum is also perm...

  7. Microstructure and Thermomechanical Properties of Magnesium Alloys Castings

    Directory of Open Access Journals (Sweden)

    P. Lichý

    2012-04-01

    Full Text Available Magnesium alloys thanks to their high specific strength have an extensive potential of the use in a number of industrial applications. The most important of them is the automobile industry in particular. Here it is possible to use this group of materials for great numbers of parts from elements in the car interior (steering wheels, seats, etc., through exterior parts (wheels particularly of sporting models, up to driving (engine blocks and gearbox mechanisms themselves. But the use of these alloys in the engine structure has its limitations as these parts are highly thermally stressed. But the commonly used magnesium alloys show rather fast decrease of strength properties with growing temperature of stressing them. This work is aimed at studying this properties both of alloys commonly used (of the Mg-Al-Zn, Mn type, and of that ones used in industrial manufacture in a limited extent (Mg-Al-Sr. These thermomechanical properties are further on complemented with the microstructure analysis with the aim of checking the metallurgical interventions (an effect of inoculation. From the studied materials the test castings were made from which the test bars for the tensile test were subsequently prepared. This test took place within the temperature range of 20°C – 300°C. Achieved results are summarized in the concluding part of the contribution.

  8. Microstructural evolution and mechanical properties of as-cast and T6-treated AA2195 DC cast alloy

    Energy Technology Data Exchange (ETDEWEB)

    Hekmat-Ardakan, A. [Universite de Sherbrook, Sherbrook, QC, Canada J1K 2R1 (Canada); Elgallad, E.M. [Universite du Quebec a Chicoutimi, Chicoutimi, QC, Canada G7H 2B1 (Canada); Ajersch, F. [Ecole Polytechnique de Montreal, Montreal, QC, Canada H3T 1J4 (Canada); Chen, X.-G., E-mail: xgrant_chen@uqac.ca [Universite du Quebec a Chicoutimi, Chicoutimi, QC, Canada G7H 2B1 (Canada)

    2012-12-15

    The use of direct chill (DC) cast ingot plates of AA2195 alloys has been recently extended for large mold applications in the plastics and automotive industries. The microstructural evolution of the as-cast AA2195 alloy was investigated using the Factsage thermodynamic software under both equilibrium and non-equilibrium conditions, and was compared with the results from differential scanning calorimetry (DSC) analysis and microstructural observations. The as-cast microstructure exhibited the presence of Al{sub 2}CuMg, Al{sub 2}Cu and Al{sub 2}CuLi intermetallic phases formed at the aluminum dendrite boundaries, which can be completely dissolved in the {alpha}-Al matrix during the solution treatment. A significant improvement in the mechanical properties of the AA2195 cast alloy after the T6 heat treatment is attributed to the formation of nano-scale {theta} Prime (Al{sub 2}Cu) and T1 (Al{sub 2}CuLi) precipitates. However, the non-uniform distribution of T1 precipitates together with the large size and low density indicate that the role of {theta} Prime precipitates in strengthening the AA2195 cast alloy is more dominant than that of the T1 precipitates, in contrast with the strengthening mechanism of the pre-deformed AA2195-T8 rolled products.

  9. Effect of Microstructure on Impact Fatigue Resistance and Impact Wear Resistance of Medium Cr-Si Cast Iron

    Institute of Scientific and Technical Information of China (English)

    LI Wei

    2007-01-01

    A great amount of iron grinding balls in tube mills have been consumed. Under this impact abrasive wear working condition, the failure of wear resistant alloying white irons grinding balls is mainly caused by fatigue spalling. The impact wear resistance of martensitic high chromium cast iron (Cr of 15 %) is not high sometimes, but its cost is not low. Thus, medium Cr-Si wear resistant cast iron is recommended. The influence of the iron on impact fatigue resistance and impact wear resistance is pronounced. Ball-on-ball impact fatigue test and high stress impact wear test of the grinding balls have been carried out. The results show that the impact fatigue resistance (IFR) and impact wear resistance (IWR) of medium Cr-Si cast iron are superior to those of martensitic high chromium cast iron (Cr of 15%). The main reasons are that (1) the stress in medium Cr-Si cast iron is released in the as-cast state; (2)the matrix is fine pearlite with better toughness and plasticity; (3) the pearlite is more stable compared with a retained austenite under repeated impact load and less phase transformation can take place; (4) high silicon content improves the morphology of eutectic carbide; (5) there is no secondary carbide which results in less crack sources. All these factors are beneficial to improvement of impact fatigue spalling resistance. The eutectic carbide M7C3 is the main constituent to resist wear.

  10. The efect of cooling rate on the properties of alloyed cast-iron sizing roll

    Directory of Open Access Journals (Sweden)

    P. Jelić

    2010-01-01

    Full Text Available Directional heat transfer was investigated by temperature measurements in the casting and in the mould using thermocouples. Measurements were performed in operating conditions during pouring, solidification, and cooling of the casting. Total measurement time was 35,5 hours. After cutting, specimens were extracted for metallographic and hardness testing. Test results provided confirmation of directional heat transfer (directional cooling that would ensure acquirement of a desired casting structure and mechanical properties.

  11. Effect of Carbon Properties on Melting Behavior of Mold Fluxes for Continuous Casting of Steels

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    During continuous casting of steel, the properties of mold fluxes strongly affect the casting performance,steel quality and environment of casting operation. The high temperature microscopy technique was used to investigate the melting behaviour of mold fluxes, and drip test method was used to determine their melting rate. The results showed that free carbon is a dominant factor in governing the melting behaviour of fluxes, and the melting rate is increased with increasing carbon reactivity and decreasing carbon content.

  12. Microstructure and Properties of Cast B-Bearing High Speed Steel

    Science.gov (United States)

    Fu, Hanguang; Ma, Shengqiang; Hou, Jianqiang; Lei, Yongping; Xing, Jiandong

    2013-04-01

    Microstructure, mechanical properties, and wear resistance of B-bearing high-speed steel (HSS) roll material containing 0.90-1.00% C, 1.3-1.5% B, 0.8-1.5% W, 0.8-1.5% Mo, 4.6-5.0% Cr, 1.0-1.2% V, and 0.15-0.20% Ti were studied by means of the optical microscopy (OM), the scanning electron microscopy (SEM), x-ray diffraction (XRD), hardness, impact toughness, and pin-on-disk abrasion tests. The results showed that as-cast structure of B-bearing HSS consisted of α-Fe-, M23(B,C)6-, M3(B0.7C0.3)-, and M2(B,C)-type borocarbides, a small quantity of retained austenite, and a small amount of TiC. The hardness and impact toughness values of as-cast B-bearing HSS reached 65-67 HRC and 80-85 kJ/cm2, respectively. There were many M23(B,C)6-precipitated phases in the matrix after tempering, and then, with increasing temperature, the amount of precipitated phases increased considerably. Hardness of B-bearing HSS gradually decreased with the increasing tempering temperature, and the change of tempering temperature had no obvious effect on impact toughness. B-bearing HSS tempered at 500 °C has excellent wear resistance, which can be attributed to the effect of boron.

  13. Research of Mechanical Property Gradient Distribution of Al-Cu Alloy in Centrifugal Casting

    Science.gov (United States)

    Sun, Zhi; Sui, Yanwei; Liu, Aihui; Li, Bangsheng; Guo, Jingjie

    Al-Cu alloy castings are obtained using centrifugal casting. The regularity of mechanical property gradient distribution of Al-Cu alloy castings with the same centrifugal radius at different positions is investigated. The result shows that the tensile strength, yield strength, elongation and microscope hardness exhibit the following gradient distribution characteristic — high on both sides and low on the center. The trend of mechanical property gradient distribution of Al-Cu alloy increases with the increase in the rotation speed. Moreover, the mechanical properties of casting centerline two sides have asymmetry. The reason is that the grain size of casting centerline two sides and Al2Cu phase and Cu content change correspondingly.

  14. New crosslinked cast films based on poly(vinyl alcohol: Preparation and physico-chemical properties

    Directory of Open Access Journals (Sweden)

    C. Birck

    2014-12-01

    Full Text Available In this paper, we propose a green route to prepare insoluble poly(vinyl alcohol (PVOH cast films with potential application as antimicrobial packaging. First PVOH films were cast from different aqueous solutions and analyzed by Differential Scanning Calorimetry (DSC and Dynamic Mechanical Analysis (DMA to determine their physical properties under two storage conditions. In order to obtain insoluble films, PVOH was then crosslinked by citric acid (CTR as confirmed by Nuclear Magnetic Resonance (NMR analyses. The crosslinking reaction parameters (curing time, crosslinker content were studied by comparing the characteristics of PVOH/CTR films, such as free COOH content and glass transition temperature (Tg value, as well as the impact of the crosslinking reaction on mechanical properties. It was found that for 40 and 10 wt% CTR contents, 120 and 40 min of crosslinking times were necessary to bind all CTR respectively. Brittle films were obtained for 40 wt% CTR whereas 10 wt% CTR content led to ductile films. Finally, films containing hydroxypropyl-β-cyclodextrin (HPβCD, chosen as a potential vector of antimicrobial agent, were prepared. The obtained results show that the incorporation of HPβCD in the PVOH matrix does not mainly influence the physical and mechanical properties of the films.

  15. Effect of bainite transformation and retained austenite on mechanical properties of austempered spheroidal graphite cast steel

    Science.gov (United States)

    Takahashi, Toshio; Abe, Toshihiko; Tada, Shuji

    1996-06-01

    Austempered ductile iron (ADI) has excellent mechanical properties, but its Young's modulus is low. Austempered spheroidal graphite cast steel (AGS) has been developed in order to obtain a new material with superior mechanical properties to ADI. Its carbon content (approximately 1.0 pct) is almost one-third that of a standard ADI; thus, the volume of graphite is also less. Young's modulus of AGS is 195 to 200 GPa and is comparable to that of steel. Austempered spheroidal graphite cast steel has an approximately 200 MPa higher tensile strength than ADI and twice the Charpy absorbed energy of ADI. The impact properties and the elongation are enhanced with increasing volume fraction of carbon-enriched retained austenite. At the austempering temperature of 650 K, the volume fraction of austenite is approximately 40 pct for 120 minutes in the 2.4 pct Si alloy, although it decreases rapidly in the 1.4 pct Si alloy. The X-ray diffraction analysis shows that appropriate quantity of silicon retards the decomposition of the carbon-enriched retained austenite. For austempering at 570 K, the amount of the carbon-enriched austenite decreases and the ferrite is supersaturated with carbon, resulting in high tensile strength but low toughness.

  16. Effect of bainite transformation and retained austenite on mechanical properties of austempered spheroidal graphite cast steel

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Toshio; Abe, Toshihiko; Tada, Shuji [Tohoku National Industrial Research Inst., Sendai (Japan). Materials Engineering Div.

    1996-06-01

    Austempered ductile iron (ADI) has excellent mechanical properties, but its Young`s modulus is low. Austempered spheroidal graphite cast steel (AGS) has been developed in order to obtain a new material with superior mechanical properties to ADI. Its carbon content (approximately 1.0 pct) is almost one-third that of a standard ADI; thus, the volume of graphite is also less. Young`s modulus of AGS is 195 to 200 GPa and is comparable to that of steel. Austempered spheroidal graphite cast steel has an approximately 200 MPa higher tensile strength than ADI and twice the Charpy absorbed energy of ADI. The impact properties and the elongation are enhanced with increasing volume fraction of carbon-enriched retained austenite. At the austempering temperature of 650 K, the volume fraction of austenite is approximately 40 pct for 120 minutes in the 2.4 pct Si alloy, although it decreases rapidly in the 1.4 pct Si alloy. The X-ray diffraction analysis shows that appropriate quantity of silicon retards the decomposition of the carbon-enriched retained austenite. For austempering at 570 K, the amount of the carbon-enriched austenite decreases and the ferrite is supersaturated with carbon, resulting in high tensile strength but low toughness.

  17. The surface layer of austempered ductile iron investment castings properties

    OpenAIRE

    D. Myszka; M. Kłębczyk; Zych, A.; L. Kwiatkowski

    2009-01-01

    The article presents a unique process of carbonnitriding and nitriding the precision casting surfaces of austempered ductile iron. The results of the research are pointing that adequate process parameters allow to obtain multiple increase of wear resistance and a significant increase of corrosion resistance. Also, changes of cast microstructure and hardness are presented.

  18. The surface layer of austempered ductile iron investment castings properties

    Directory of Open Access Journals (Sweden)

    D. Myszka

    2009-01-01

    Full Text Available The article presents a unique process of carbonnitriding and nitriding the precision casting surfaces of austempered ductile iron. The results of the research are pointing that adequate process parameters allow to obtain multiple increase of wear resistance and a significant increase of corrosion resistance. Also, changes of cast microstructure and hardness are presented.

  19. Microstructure and mechanical properties of lost foam cast 356 alloys

    Directory of Open Access Journals (Sweden)

    Qi-gui Wang

    2015-05-01

    Full Text Available Microstructure and mechanical properties of lost foam cast aluminum alloys have been investigated in both primary A356 (0.13% Fe and secondary 356 (0.47%. As expected, secondary 356 shows much higher content of Fe-rich intermetallic phases, and in particular the porosity in comparison with primary A356. The average area percent and size (length of Fe-rich intermetallics change from about 0.5% and 6 祄 in A356 to 2% and 25 祄 in 356 alloy. The average area percent and maximum size of porosity also increase from about 0.4% and 420 祄 to 1.4% and 600 祄, respectively. As a result, tensile ductility decreases about 60% and ultimate tensile strength declines about 8%. Lower fatigue strength was also experienced in the secondary 356 alloy. Low cycle fatigue (LCF strength decreased from 187 MPa in A356 to 159 MPa in 356 and high cycle fatigue (HCF strength also declined slightly from 68 MPa to 64 MPa.

  20. The Properties of Ammonium Dinitramine (ADN): Part 2: Melt Casting

    Science.gov (United States)

    Hahma, A.; Edvinsson, H.; Östmark, H.

    2010-04-01

    A melt casting technique for ammonium dinitramine (ADN) and ADN/aluminum was developed. ADN proved relatively easy to cast, when 1% of magnesium oxide was used as a stabilizer and crystallization kernels. Densities of ADN/MgO 99/1 were 92 to 97% of theoretical mean density (TMD) and those of ADN/Al/MgO 64/35/1 were between 95 and 99% of TMD. Sedimentation of Al in the melt was prevented and the particle wetting was ensured by selecting a suitable particle size for Al. No gelling agents or other additives were used. The casting process and factors influencing it are discussed.

  1. Effect of selected physical properties of waxes on investments and casting shrinkage.

    Science.gov (United States)

    Ito, M; Yamagishi, T; Oshida, Y; Munoz, C A

    1996-02-01

    This study evaluated the relationship between flow characteristics, bending strength, and softening temperature of paraffin and dental inlay waxes to casting shrinkage when patterns were invested with a phosphate-bonded investment. This study found that the casting shrinkage decreased as the flow of the wax pattern increased. If a low flow wax is used or if there is a need for a thick pattern, the size of the casting ring should be increased. When wax patterns are formed for cast restorations, it is important to select the type of wax with the most desirable properties for the margin and the occlusal portions. Moreover, to accurately fabricate castings, it is necessary to understand the physical properties of the chosen waxes.

  2. Mechanical Properties of V-, Nb-, and Ti-bearing As-cast Microalloyed Steels

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The influence of microalloying additions on the mechanical properties of a low-carbon cast steel containing combinations of V, Nb, and Ti in the as-cast condition was evaluated. Tensile and hardness test results indicated that good combinations of strength and ductility could be achieved by V and Nb additions. While the yield strength and UTS (ultimate tensile strength) increased up to the range of 378-435 MPa and 579-596 MPa, respectively in the microalloyed heats, their total elongation ranged from 18% to 23%. The presence of Ti, however, led to some reduction in the strength. Microstructural studies including scanning electron microscopy (SEM) and optical microscopy revealed that coarse TiN particles were responsible for this behavior. The Charpy impact values of all compositions indicated that microalloying additions significantly decreased the impact energy and led to the dominance of cleavage facets on the fracture surfaces. It seems that the increase in the hardness of coarse ferrite grains due to the precipitation hardening is the main reason for brittle fracture.

  3. New Possibilities of Shaping the Surface Properties in Austempered Ductile Iron Castings

    OpenAIRE

    D. Myszka

    2013-01-01

    The paper presents recent developments concerning the formation of surface layer in austempered ductile iron castings. It was found thatthe traditional methods used to change the properties of the surface layer, i.e. the effect of protective atmosphere during austenitising or shot peening, are not fully satisfactory to meet the demands of commercial applications. Therefore, new ways to shape the surface layer and the surface properties of austempered ductile iron castings are searched for, to...

  4. Statistical fatigue properties of ductile cast irons; Kyujo kokuen chutetsu no hiro kyodo no tokeiteki seishitsu

    Energy Technology Data Exchange (ETDEWEB)

    Hasegawa, N.; Nishikawa, Y.; Inaba, K. [Gifu University, Gifu (Japan). Faculty of Engineering; Fukuyama, K. [Gifu Prefectural Police Headquarters, Gifu (Japan)

    1995-09-15

    Rotating bending fatigue tests of smooth specimens were carried out at room temperature on a pearlitic ductile cast iron (PDI) and austempered ductile cast iron (ADI). No significant difference due to sampling position from cast blocks in both materials was found in fatigue limit and fatigue life distribution. Then, the statistical fatigue properties of ferritic (FDI), ferritic/pearlitic (FPDI), pearlitic and austempered ductile cast irons were investigated. The fatigue life distributions of all ductile irons were well represented by the three parameter Weibull distribution modified by the saturated probability of failure. The shape parameters of FDI, FPDI and PDI were in proportion to {sigma}/{sigma}w independent on micro structure, while the shape parameters of both stress levels in ADI were smaller than unity. The fatigue strength of ADI was highest, but the scatter of fatigue life was largest among the all cast irons. 13 refs., 15 figs., 7 tabs.

  5. MICROSTRUCTURE AND PROPERTIES OF ZL201 ALLOY OBTAINED BY NEAR-LIQUIDUS ELECTROMAGNETIC CASTING

    Institute of Scientific and Technical Information of China (English)

    P. Wang; L.F. Sh; G.M. Lu; J.Z. Cui

    2005-01-01

    The microstructures of ZL201 alloy slurry prepared by near-liquidus electromagnetic casting(NLEMC), electromagnetic casting(EMC), and near-liquidus casting(NLC) were investigated by means of electron microscopy and image analysis. Mechanical properties of as-cast alloys were determined. The results show that the NLEMC induces a fine, uniform, and equiaxed grain structure with a mean equal-area-circle grain diameter of 32.8μm. The as-cast alloy has a hardness of HV122.8 and a tensile strength of 368MPa. Both of them are better than those of the alloys prepared by EMC and by NLC. The mechanism of grain refinement in the NLEMC alloy slurry was discussed.

  6. Correlation of mechanical properties with the acoustic properties in case of an experimental white cast iron

    Science.gov (United States)

    Gȋrneţ, A.; Stanciu, S.; Chicet, D.; Axinte, M.; Goanţă, V.

    2016-08-01

    The general and traditional opinion regarding the materials used to build bells, musical instruments or sound transmitters is that those materials must be only from the bronze alloyed with tin category. In order to approach this idea from a scientific point of view, the materials with acoustic properties must be analyzed starting from the physical theory and experimental determination that sound travels only through bodies with elastic properties. It has been developed an experimental white cast iron, medium alloyed with Cr and Ni, in order to obtain a material with special acoustic properties. There were determined on specific samples: the vibration damping capacity, the unit energy, the tensile strength and elasticity modulus. These properties were correlated with the properties of other known acoustic materials.

  7. The effect of hot isostatic pressing on crack initiation, fatigue, and mechanical properties of two cast aluminum alloys

    Science.gov (United States)

    Rich, T. P.; Orbison, J. G.; Duncan, R. S.; Olivero, P. G.; Peterec, R. H.

    1999-06-01

    This article presents the results of an experimental materials testing program on the effect of hot isostatic pressing (HIP) on the crack initiation, fatigue, and mechanical properties of two cast aluminum alloys: AMS 4220 and 4225. These alloys are often used in castings for high temperature applications. Standard tensile and instrumented Charpy impact tests were performed at room and elevated temperatures. The resulting data quantify improvements in ultimate tensile strength, ductility, and Charpy impact toughness from the HIP process while indicating little change in yield strength for both alloys. In addition standard fracture mechanics fatigue tests along with a set of unique fatigue crack initiation tests were performed on the alloys. Hot isostatic pressing was shown to produce a significant increase in cycles to crack initiation for AMS 4225, while no change was evident in traditional da/dN fatigue crack growth. The data permits comparisons of the two alloys both with and without the HIP process.

  8. Mechanical properties of As-cast and heat-treated ZA-27 alloy/short glass fiber composites

    Science.gov (United States)

    Sharma, S. C.; Girish, B. M.; Satish, B. M.; Kamath, R.

    1998-02-01

    This paper reports on the mechanical properties of as-cast and heat-treated ZA-27 alloy composites reinforced with glass fibers from 1 to 5 wt%. The composites were fabricated using the Compocasting method, in which short glass fibers were introduced into the vortex created in the molten alloy through an impeller rotated at 500 rpm. The molten mass was thoroughly stirred and poured into permanent molds and squeezed under pressure. The specimens were heat treated at 320 °C for 1, 2,3, and 4 h. The tests on the as-cast composites revealed that as the glass content in the composites was increased, the ultimate tensile strength (UTS), compressive strength, and hardness of the composite increased, while the ductility and impact strength were decreased. Heat treatment was found to improve significantly the ductility, compressive strength, and impact strength, while the hardness and UTS were reduced. This paper discusses the behavior of these composites.

  9. Rare earth metals influence on mechanical properties and crack resistance of GP240GH and G17CrMo5-5 cast steels

    Directory of Open Access Journals (Sweden)

    M. Gajewski

    2009-10-01

    Full Text Available This paper presents results of research on modification influence of REM on mechanical properties and crack resistance of GP240GH cast carbon steel and G17CrMo5-5 high-temperature cast steel. The tests have been performed on successive industrial melts. The rare earth metals were put into the ladle during tapping of heat melt from the furnace. Each time ca 2000 kg of liquid metals were modified. Because of this the amount of sulphur in the cast steel was decreased and the non-metallic inclusion morphology was significantly changed. There were tested mechanical properties (Re,Rm, plastic properties (A5,Z and impact strength (KV, and on the basis of the three-point bend test the KJC stress intensity factor was evaluated. It was noticed that the REM modification brings essential increase of impact strength as well as fracture toughness determined by KJC factor.

  10. Effects of casting and post casting annealing on xylene isomer transport properties of Torlon® 4000T films

    KAUST Repository

    Chafin, Raymond

    2010-07-01

    Procedures for Torlon® 4000T membrane formation were developed to provide attractive and repeatable xylene separation properties. Torlon® 4000T membrane films cast by our method were investigated in terms of thermally induced imidization, molecular weight enhancement, and solvent removal. After development of the Torlon® 4000T casting procedure, pervaporation of a xylene mixture (i.e. 30% para-xylene, 30% meta-xylene, 30% ortho-xylene, and 10% ethylbenzene) was performed in both Torlon® 4000T and post casting annealed Torlon® 4000T films. The xylene pervaporation in annealed Torlon® 4000T film at 200°C gave a permeability of 0.25 Barrer and a selectivity of 3.1 (para/ortho) and 2.1 (para/meta) respectively. A so-called " permeability collapse" reflecting an accelerated reduction in the free volume is consistent with significant temperature-induced changes in the films observed after thermal annealing at 300°C. This conditioning effect is induced by a combination of heat treatment and the presence of the interacting aromatic penetrants. Optical methods were used to verify that the density of annealed samples exposed to xylene for 5 days eventually increased, suggesting that the membrane is originally swollen upon initial xylene exposure, and then relaxes to a more densified, and more discriminating state. © 2010 Elsevier Ltd.

  11. Influence of heat treatment on microstructure and properties of GX12CrMoVNbN9-1 cast steel

    Directory of Open Access Journals (Sweden)

    G. Golański

    2010-07-01

    Full Text Available The paper presents results of research on the influence of multistage heat treatment on microstructure and properties of high-chromiummartensitic GX12CrMoVNbN9 – 1 (GP91 steel. The material under investigation were samples taken out from a test coupon. Heattreatment of GP91 cast steel was performed at the parameters of temperature and time typical of treatment for multi-ton steel casts. The research has proved that in the as-received condition (as-cast state GP91 cast steel was characterized by a coarse grain, martensitic microstructure which provided the required standard mechanical properties. The heat treatment of GP91 cast steel contributed to obtainment of a fine grain microstructure of high tempered martensite with numerous precipitations of carbides of diverse size. The GP91 cast steel structure received through heat treatment made it possible to obtain high plastic properties, particularly impact strength, maintaining strength properties on the level of the required minimum.

  12. Density and Mechanical Properties of Aluminum Lost Foam Casting by Pressurization during Solidification

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Porosity is thought to be severe in aluminum alloy castings produced by lost foam process due to the pyrolysis of the polystyrene foam pattern during pouring, which results in detrimental effect in mechanical property.The slow solidification rate promotes the formation of gassing pin holes, and relative weakness of the thermal gradients can cause micro-shrinkage if the outline of the part complicates feeding in the lost foam casting. One of the methods to eliminate the porosity is to apply high pressure to the molten metal like an isostatic forging during solidification. Fundamental experiments were carried out to evaluate the effect of the external pressure on the porosity and mechanical properties of A356.2 alloy bar in the lost foam casting. Solidification time and porosity decreased with increasing the applied pressure during solidification. Applying external pressure was effective in decreasing the porosity and increasing the elongation of the lost foam casting.

  13. Mapping of mechanical properties of cast iron melts using non-destructive structuroscopy

    Directory of Open Access Journals (Sweden)

    J. Dočekal

    2008-07-01

    Full Text Available The contribution is focused on mapping of mechanical properties using methods of non-destructive structuroscopy of cast irons, which are a result of research at TU of Liberec and Institute of Physics of ASCR. Investigated samples become from melts of FOCAM s.r.o Olomouc Foundry shop. It compares data of mechanical properties obtained using ultrasound method with data from magnetic spot method and MAT. These are interpreted by mathematic models applicable in practice. In the following it concerns to derivation of loading tensile curve method, which can be used to obtain yield and fatigue strength limits even for cast irons with flake graphite. In spite of promising results reported by literature the experiments are bothered with error. This method can be applied to structure checking both before casting and at vendor inspection of castings.

  14. Effect of Zircon Silicate Reinforcements on the Microstructure and Properties of as Cast Al-4.5Cu Matrix Particulate Composites Synthesized via Squeeze Cast Route

    Directory of Open Access Journals (Sweden)

    E. G. Okafor

    2010-06-01

    Full Text Available The as-cast microstructure and properties of Al-4.5Cu/ZrSiO4 particulate composite synthesized via squeezed casting route was studied, varying the percentage ZrSiO4 in the range of 5-25wt%. The result obtained revealed that addition of ZrSiO4 reinforcements, increased the hardness value and apparent porosity by 107.65 and 34.23% respectively and decrease impact energy by 43.16 %. As the weight percent of ZrSiO4 increases in the matrix alloy, the yield and ultimate tensile strength increased by 156.52 and 155.81% up to a maximum of 15% ZrSiO4 addition respectively. The distribution of the brittle ZrSiO4 phase in the ductile matrix alloy led to increase strength and hardness values. These results had shown that, additions of ZrSiO4 particles to Al-4.5Cu matrix alloy improved properties.

  15. Effect of casting methods on the structure and properties of tin babbit

    Science.gov (United States)

    Potekhin, B. A.; Il'yushin, V. V.; Khristolyubov, A. S.

    2009-07-01

    Dependence of the properties of babbit of grade B83 on the structure formed due to different methods of casting is determined. A novel advanced method of centrifugal casting of babbit B83 is suggested, which ensures crystallization of SnSb and Cu3Sn intermetallics from a turbulently moving melt. This not only removes segregation but also transfers the acute-angle SnSb intermetallic into a globular form.

  16. Solidification, growth mechanisms, and associated properties of Al-Si and magnesium lightweight casting alloys

    Energy Technology Data Exchange (ETDEWEB)

    Hosch, Timothy [Iowa State Univ., Ames, IA (United States)

    2010-01-01

    often contain additions of heavier elements, such as zinc, zirconium, and rare earth elements, which significantly improve high temperature performance. However, additions of these elements can lead to macrosegregational effects in castings, which are detectable by radiographic scans. The effect of these flow-line indications on alloy mechanical properties is not well quantified. An examination of these flow-line indications and their effects on mechanical properties in three magnesium-based casting alloys was performed here in order to determine the best practice for dealing with affected castings. Preliminary results suggest the flow-lines do not measurably impact bulk material properties. Three additional methods of characterizing three-dimensional material structures are also presented: a minimum spanning tree analysis is utilized to quantify local structure in Cu-Zr liquid phase simulations obtained from molecular dynamics; the radial distribution function is applied to directionally solidified Al-Si structures in an attempt to extract local spacing data; and the critical diameter measurement is also defined and applied to irregular eutectic Al-Si structures.

  17. Solidification, growth mechanisms, and associated properties of aluminum-silicon and magnesium lightweight casting alloys

    Science.gov (United States)

    Hosch, Timothy Al

    often contain additions of heavier elements, such as zinc, zirconium, and rare earth elements, which significantly improve high temperature performance. However, additions of these elements can lead to macrosegregational effects in castings, which are detectable by radiographic scans. The effect of these flow-line indications on alloy mechanical properties is not well quantified. An examination of these flow-line indications and their effects on mechanical properties in three magnesiumbased casting alloys was performed here in order to determine the best practice for dealing with affected castings. Preliminary results suggest the flow-lines do not measurably impact bulk material properties. Three additional methods of characterizing three-dimensional material structures are also presented: a minimum spanning tree analysis is utilized to quantify local structure in Cu-Zr liquid phase simulations obtained from molecular dynamics; the radial distribution function is applied to directionally solidified Al-Si structures in an attempt to extract local spacing data; and the critical diameter measurement is also defined and applied to irregular eutectic Al-Si structures.

  18. Effect of Nb on Structure and Mechanical Properties of Chilled Cast Iron at Room and Elevated Temperatures

    Institute of Scientific and Technical Information of China (English)

    Qijie ZHAI; Li FU; Huaying ZHAI

    2004-01-01

    Effect of Nb on microstructure and mechanical properties of chilled cast iron at room and elevated temperatures is studied in this research. The results demonstrate that the cast structure and mechanical properties of chilled cast iron at room and elevated temperatures are improved with the addition of trace amount of Nb. However, if Nb was added too much, the cast structure and mechanical properties of chilled cast iron would deteriorate. The suitable content of Nb in chilled cast iron is about 0.05% (mass fraction). Except the dissolution in the matrix of cast iron the excessive Nb will form Nb-rich phases in three morphologies. Those are lumpy NbC, complicated strip-like phase and compound with pearlite structure.

  19. Influences of Casting Pressure Conditions on the Quality and Properties of a Magnesium Cylinder Head Cover Die Casting

    Institute of Scientific and Technical Information of China (English)

    Wenhui LIU; Yangai LIU; Shoumei XIONG; Baicheng LIU; Y. Matsumoto; M. Murakami

    2005-01-01

    Casting pressure conditions have great influences on the casting defects, such as gas porosity, shrinkage porosity and gas holes. A Mg cylinder head cover die casting was used to experimentally study the influences of casting pressure,the loading time and the piston position of pressure intensification on the variation of pressure and the quality of casting. The results show that casting pressure, the loading time and the piston position of pressure intensification have great influences on the pressure variations in the mold, the quality and performance of casting. The external quality, the density and the tensile strength of casting were improved with the increase of casting pressure and the piston position of pressure intensification and the decrease of the loading time of pressure intensification.

  20. Mechanical Properties and Corrosion-Abrasion Wear Behavior of Low-Alloy MnSiCrB Cast Steels Containing Cu

    Science.gov (United States)

    Luo, Kaishuang; Bai, Bingzhe

    2011-01-01

    Two medium carbon low-alloy MnSiCrB cast steels containing different Cu contents (0.01 wt pct and 0.62 wt pct) were designed, and the effect of Cu on the mechanical properties and corrosion-abrasion wear behavior of the cast steels was studied. The results showed that the low-alloy MnSiCrB cast steels obtained excellent hardenability by a cheap alloying scheme. The microstructure of the MnSiCrB cast steels after water quenching from 1123 K (850 °C) consists of lath martensite and retained austenite. After tempering at 503 K (230 °C), carbides precipitated, and the hardness of the cast steels reached 51 to 52 HRC. The addition of Cu was detrimental to the ductility and impact toughness but was beneficial to the wear resistance in a corrosion-abrasion wear test. The MnSiCrB cast steel with Cu by the simple alloying scheme and heat treatment has the advantages of being high performance, low cost, and environmentally friendly. It is a potential, advanced wear-resistant cast steel for corrosion-abrasion wear conditions.

  1. The influence of calcium on technological properties and micropurity of steel castings

    Directory of Open Access Journals (Sweden)

    J. Hampl

    2016-07-01

    Full Text Available The paper analyzes the technological parameters, micro-purity and mechanical properties of castings of steel alloyed with calcium. The effect of calcium on the steel was analyzed on samples taken in the process of casting heavy castings and ingots of the weight of ranging from 40 000 to 60 000 kg. Samples for the determination of the liquidus temperature and the solidus temperature of cast steels were analysed using differential thermal analysis (DTA. The production of low alloyed steel grades was performed on the EAF - ASEA-SKF facilities and the production of highalloyed steels on the EAF - ASEA-SKF - SS-VOD facilities. The purity calcium was added into the steel by the injection of a stuffed profile.

  2. Fabrication and properties of strip casting 4.5 wt% Si steel thin sheet

    Science.gov (United States)

    Zu, Guoqing; Zhang, Xiaoming; Zhao, Jingwei; Wang, Yuqian; Yan, Yi; Li, Chengang; Cao, Guangming; Jiang, Zhengyi

    2017-02-01

    Three 4.5 wt% Si steel thin sheets with different thicknesses were efficiently fabricated by twin-roll strip casting, warm rolling and cold rolling followed by final annealing. A comprehensive investigation from the workability of the as-cast strip to the magnetic property of the produces was performed to illustrate the superiority of the new materials. The results show that the as-cast strip, which has a much lower Vickers hardness than that of the 6.5 wt% Si steel, is suitable for rolling processing. The X-ray diffraction (XRD) and transmission electron microscopy (TEM) studies confirm that no ordering phase exists in the as-cast strip. The cold-rolled thin sheets exhibit good surface quality without edge cracks. Furthermore, all the three 4.5 wt% Si steel thin sheets possess relative strong //ND texture and present high magnetic inductions and low iron losses after finial annealing.

  3. Influence of fabricating process on microstructure and properties of spheroidal cast tungsten carbide powder

    Institute of Scientific and Technical Information of China (English)

    DAI Yu; TAN Xing-long; LI Yu-xi; YANG Jian-gao; HUANG Bai-yun

    2005-01-01

    A super-high temperature furnace was developed to fabricate spheroidal cast tungsten carbide powder with excellent flowability and fine feathery structure in a large scale. Optical microscope and scanning electron microscope were taken to characterize the morphology and microstructure of cast tungsten carbide powder. X-ray diffractometry was used to analyze the phase composition of powders involved. It is found that the carbon potential in the furnace and feeding speed play an important role on the microstructure, morphology and properties of the spheroidal cast tungsten carbide powder. As carbon potential is between 0.3% and 0.9% in the furnace, cast tungsten carbide powder with hardness over 2800(HV0.5 ), flowability over 7. 1 s/50 g and tap density over 10.3 g/cm3 is obtained.

  4. Property enhancement of cast iron used for nuclear casks

    Science.gov (United States)

    Behera, R. K.; Mahto, B. P.; Dubey, J. S.; Mishra, S. C.; Sen, S.

    2016-01-01

    Ductile iron (DI) is a preferred material for use in various structural, automotive, and engineering fields because of its excellent combination of strength, toughness, and ductility. In the current investigation, we elucidate the relationship between the morphological and mechanical properties of DI intended for use in safety applications in the nuclear industry. DI specimens with various alloying elements were subjected to annealing and austempering heat treatment processes. A faster cooling rate appeared to increase the nodule count in austempered specimens, compensating for their nodularity value and subsequently decreasing their ductility and impact strength. The ductility and impact energy values of annealed specimens increased with increasing ferrite area fraction and nodularity, whereas an increase in the amounts of Ni and Cr resulted in an increase of hardness via solid solution strengthening. Austempered specimens were observed to be stronger than annealed specimens and failed in a somewhat brittle manner characterized by a river pattern, whereas the ductile failure mode was characterized by the presence of dimples.

  5. Property enhancement of cast iron used for nuclear casks

    Institute of Scientific and Technical Information of China (English)

    RK Behera; BP Mahto; JS Dubey; SC Mishra; S Sen

    2016-01-01

    Ductile iron (DI) is a preferred material for use in various structural, automotive, and engineering fields because of its excellent combination of strength, toughness, and ductility. In the current investigation, we elucidate the relationship between the morphological and mechanical properties of DI intended for use in safety applications in the nuclear industry. DI specimens with various alloying elements were subjected to annealing and austempering heat treatment processes. A faster cooling rate appeared to increase the nodule count in austempered specimens, compensating for their nodularity value and subsequently decreasing their ductility and impact strength. The ductility and impact energy values of annealed specimens increased with increasing ferrite area fraction and nodularity, whereas an increase in the amounts of Ni and Cr resulted in an increase of hardness via solid solution strengthening. Austempered specimens were observed to be stronger than an-nealed specimens and failed in a somewhat brittle manner characterized by a river pattern, whereas the ductile failure mode was character-ized by the presence of dimples.

  6. Effect of heat treatment on microstructure, mechanical properties and erosion resistance of cast 23-8-N nitronic steel

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Avnish, E-mail: avnishmnit@gmail.com [Department of Metallurgical and Materials Engineering, Malaviya National Institute of Technology, Jaipur 302017 (India); Sharma, Ashok, E-mail: ashok.mnit12@gmail.com [Department of Metallurgical and Materials Engineering, Malaviya National Institute of Technology, Jaipur 302017 (India); Goel, S.K. [Star Wire India Ltd., Ballabgarh, Haryana 121404 (India)

    2015-06-18

    Effects of heat treatment on microstructure, mechanical properties and erosion behavior of cast 23-8-N nitronic steel were studied. A series of heat treatments were carried out in the temperature range of 1180–1240 °C to observe the effect on microstructure. Optimum heat treatment cycle was obtained at 1220 °C for holding time of 150 min, which leads to dissolution of carbides, formation of equiaxed grains and twins. Heat treatment has shown improvement in tensile strength, toughness, impact strength and work hardening capacity, however at the cost of marginal reduction in hardness and yield strength. This resulted in improvement of erosion resistance of cast 23-8-N nitronic steel. The microstructures, fractured surfaces and phases were studied by optical microscopy, field emission scanning electron microscopy (FESEM) and X-ray diffraction (XRD) analysis respectively.

  7. Influence of cooling rate on the structure and mechanical properties of G17CrMoV5 – 10 cast steel

    Directory of Open Access Journals (Sweden)

    G. Golański

    2009-07-01

    Full Text Available The paper presents results of research on the influence of cooling rate on the structure and properties of G17CrMoV5 – 10 (L17HMF cast steel. The material for research was a section taken out from an outer cylinder of a steam turbine body after about 250 000 hours of operation at the temperature of 535°C and pressure 9 MPa. The investigated cast steel was subjected to heat treatment which consisted in cooling at the rates corresponding to the processes, such as: bainitic hardening, normalizing and full annealing. Tempering after the process of cooling from austenitizing temperature was carried out at the temperatures of: 700, 720 and 740°C. Performed research has proved that structures obtained after bainitic hardening and normalizing are characterized by a large strength margin which allows to apply high temperatures of tempering. It has been shown that the cast steel of bainitic structure, with similar mechanical properties as the cast steel of bainitic – ferritic structure, is characterized by almost twice as high impact energy. Full annealing and tempering of the examined cast steel ensures only the required impact strength, with mechanical properties comparable to those after service.

  8. Effect of thermophysical property and coating thickness on microstructure and characteristics of a casting

    Directory of Open Access Journals (Sweden)

    Ai-chao Cheng

    2017-01-01

    Full Text Available A new improved investment casting technology (IC has been presented and compared with the existing IC technology such as lost foam casting (LFC. The effect of thermophysical property and coating thickness on casting solidification temperature field, microstructure and hardness has been investigated. The results show that the solidification rate decreases inversely with the coating thickness when the coating contains silica sol, zircon powder, mullite powder and defoaming agent. In contrast, the solid cooling rate increases as the coating thickness increases. However, the solidification rate and solid cooling rate of the casting produced by the existing IC and the improved IC are very similar when the coating thickness is 5 mm, so the microstructure and hardness of a container corner fitting produced by the improved IC and the existing IC are similar. The linear regression equation for the grain size (d and cooling rate (v of the castings is d= –0.41v+206.1. The linear regression equation for the content of pearlite (w and solid cooling rate (t is w=1.79t + 6.71. The new improved IC can greatly simplify the process and decrease the cost of production compared with the existing IC. Contrasting with LFC, container corner fittings produced by the new improved IC have fewer defects and better properties. It was also found that the desired microstructure and properties can be obtained by changing the thermophysical property and thickness of the coating.

  9. Selected aspects of the piece production of iron alloy castings in terms of their environmental impact

    Directory of Open Access Journals (Sweden)

    Z. Maniowski

    2010-07-01

    Full Text Available Problems of environmental protection are nowadays one of the top priorities in a policy programme adopted by the European Community.Reducing the negative impact of the domestic foundry industry on environment should result from complex and long-lasting activities,targeted not only at modernisation of the dust collecting units, but also at searches and implementation of alternative, innovative and more pro-ecology oriented means and techniques of casting manufacture. Reducing to minimum the level of emissions escaping to the environment should be considered at all stages of the casting manufacturing process. In this study, the discussion was restricted to the process of the manufacture of moulds and cores for piece production of the heavy castings. The environmental impact of the technology of making moulds and cores in sands with chemical binders, used most often in piece production of large castings poured from iron alloys, was highlighted. As an alternative technology of mould preparation for the piece production of castings, the ecological and economic aspects of the full mould process were presented.

  10. Strategies to reduce the environmental impact of an aluminium pressure die casting plant: A scenario analysis

    NARCIS (Netherlands)

    Neto, B.; Kroeze, C.; Hordijk, L.; Costa, C.; Pulles, M.P.J.

    2009-01-01

    This study explores a model (MIKADO) to analyse scenarios for the reduction of the environmental impact of an aluminium die casting plant. Our model calculates the potential to reduce emissions, and the costs associated with implementation of reduction options. In an earlier paper [Neto, B., Kroeze,

  11. New Possibilities of Shaping the Surface Properties in Austempered Ductile Iron Castings

    Directory of Open Access Journals (Sweden)

    D. Myszka

    2013-01-01

    Full Text Available The paper presents recent developments concerning the formation of surface layer in austempered ductile iron castings. It was found thatthe traditional methods used to change the properties of the surface layer, i.e. the effect of protective atmosphere during austenitising or shot peening, are not fully satisfactory to meet the demands of commercial applications. Therefore, new ways to shape the surface layer and the surface properties of austempered ductile iron castings are searched for, to mention only detonation spraying, carbonitriding, CVD methods, etc.

  12. Thermomechanical processing and mechanical properties of hypereutectoid steels and cast irons

    Energy Technology Data Exchange (ETDEWEB)

    Lesuer, D.R.; Syn, C.K.; Sherby, O.D. (eds.)

    1998-01-01

    Recent advances in metallurgy of hypereutectoid steels and cast irons show that unique properties, such ultrahigh hardness and strength, and superplasticity, are achievable. This book focuses on the mechanical properties of hypereutectoid steels and cast irons as influenced by thermomechanical processing and microstructure. Some topics covered are: (1) Hot workability of hypereutectoid tool steels; (2) Thermomechanical processing of austempered ductile iron: An overview; (3) Mechanical behavior of ultrahigh strength, ultrahigh carbon steel wire and rod; and (4) Tensile elongation behavior of fine-grained Fe-C alloys at elevated temperatures.

  13. Properties of High Basicity Mold Fluxes for Peritectic Steel Slab Casting

    Institute of Scientific and Technical Information of China (English)

    LONG Xiao; HE Sheng-ping; XU Jian-fei; HUO Xu-ling; WANG Qian

    2012-01-01

    In high speed continuous casting of peritectic steel slabs, mold fluxes with high basicity are required for less surface defect product. However, the basicity of remaining liquid slag film tends to decrease in casting process because of the crystallization of 3CaO ·2SiO2 · CaF2. Thus, a way is put forward to improve mold fluxesr properties by raising the original basicity. In order to confirm the possibility of this method, the effect of rising original basicity on the properties of mold fluxes is discussed. Properties of high fluorine based mold fluxes with different basicities and contents of CaF2 , Na2 O, and MgO were measured, respectively. Then, properties of higher basicity mold fluxes were discussed and compared with traditional ones. The results show that increasing the basicity index can improve the melting and flow property of mold fluxes. With the increasing basicity, crystallization rate of mold fluxes increases obviously and crystallization temperature tends to decrease when the basicity exceeds 1.35. The method presen- ted before is proved as a potential way to resolve the contradiction between horizontal heat transfer controlling and solidified shell lubricating for peritectic steel slab casting. But further study on improving the flow property of liquid slag is needed. This work can be used to guide mold fluxes design for high speed continuous casting of peritectic steel slabs.

  14. Effects of Electromagnetic Centrifugal Casting on Mechanical Properties of High Chromium Cast Iron%电磁离心铸造对高铬铸铁力学性能的影响

    Institute of Scientific and Technical Information of China (English)

    孙凯; 赵琳; 刘晟荥; 张殿杰

    2012-01-01

    试验采用电磁离心铸造方法浇注高铬铸铁试样,并同常规浇注的试样进行比对.结果表明:电磁离心铸造获得试样的组织明显细化,晶粒数量增多,晶粒尺寸变小,力学性能提高.当离心转速为1 500 r/min,磁感应强度为0.5T时,电磁离心铸造铸态试样的硬度为HRC 55.3,冲击韧度为6.87 J/cm2.铸造硬度较常规试样提高10%,冲击韧度提高8%,相对耐磨性β较常规浇注试样提高5%.%The samples of high chromium cast iron were prepared by electromagnetic centrifugal casting and compared with the specimens by conventional casting. The results show that the sample obtained by electromagnetic centrifugal casting has fine structure, more grains, smaller grain size, and improved mechanical properties compared with that by conventional casting. When the centrifugal speed is 1 500 r/min, the magnetic flux density is 0.5 T, the hardness and impact toughness of cast specimens by the electromagnetic centrifugal casting are HRC 55.3 and 6.87 J/cm2, which increased by 10% and 8% , respectively compared with the conventional specimen; and the relative wear resistance β is increased by 5%.

  15. EFFECT OF CASTING MOULD ON MECHANICAL PROPERTIES OF 6063 ALUMINUM ALLOY

    Directory of Open Access Journals (Sweden)

    WASIU AJIBOLA AYOOLA

    2012-02-01

    Full Text Available Modern production methods for casting articles include the use of sand- mould, metal-mould, die, and centrifugal castings. Castings produced using sand mould is known to have peculiar microstructures depending on average size, distribution and shape of the moulding sand grains and the chemical composition of the alloy. These affect the surface finish, permeability and refractoriness of all the castings. In this paper, the effect of using CO2 process, metal mould, cement-bonded sand mould and naturally-bonded sand mould on the hardness, tensile and impact strengths of as-cast 6063 Aluminum alloy is presented. The results show that there is significant increase in hardness(33.7 HB of the alloy when naturally-bonded sand mould is used for its production over that of metal, CO2 and cement moulds. The stress-strain curves behaviour of the samples also indicated that sample from naturally bonded sand has highest tensile strength with superior ductility. The alloy shows highest impact strength when metal mould is used for sample preparation in comparison with other moulds.

  16. Microstructure-Texture-Mechanical Properties in Hot Rolling of a Centrifugal Casting Ring Blank

    Science.gov (United States)

    Qin, Fang-cheng; Li, Yong-tang; Qi, Hui-ping; Ju, Li

    2016-03-01

    Deformation characteristic of centrifugal casting 25Mn steel was investigated by compression tests, and then processing maps were established. According to the deformation parameters identified from the established processing maps and hot ring rolling (HRR) process, the industrial test for the 25Mn ring blank was performed. Optical microscope (OM) and electron backscatter diffraction (EBSD) techniques were used for detecting grain boundary features and textures of deformation structures. The morphologies and mechanisms of tensile and impact fracture were revealed. The results show that softening effect plays a dominant role in higher temperatures of 1050-1150 °C and strain rates lower than 0.1 s-1. The average grain size of the rolled 25Mn ring is about 28 μm, but the grains are more coarse and inhomogeneous on the middle layer than that on rest of the areas. The texture on the outer layer is characterized by strong {110} and weak {112} , followed by {001} and {001} on the inner layer and {110} on the center layer, which is mainly associated with the shear deformation. The rolled ring with precise geometrical dimensions and sound mechanical properties is fabricated by HRR. Tensile fracture is composed of clear river-shaped pattern and a little dimple near the inner layer and outer layer, and the fracture mechanism is mainly quasi-cleavage fracture, accompanied by dimple fracture. The morphologies of impact fracture consist of tear ridge and cleavage platform.

  17. Effects of Si on the Microstructures and Mechanical Properties of High-Chromium Cast Iron

    Science.gov (United States)

    Lai, J. P.; Pan, Q. L.; Peng, H. J.; Cui, H. R.; Xiao, C. A.

    2016-11-01

    Effect of Si on the microstructures and mechanical properties of high-chromium cast iron was investigated. The eutectic carbides are refined greatly and a transformation of matrix from austenitic matrix to pearlite is observed with increase in Si content from 0.5 to 1.5 wt.%. The refinement of eutectic microstructure is attributed to the decrease in the eutectic temperature, while the transformation from austenite matrix to pearlite is associated with the increase in solubility of carbon in the matrix. In the pearlite matrix, two types of pearlite are observed: one with lamellar pearlite, distributing at the periphery, and the second one with granular pearlite at the center. The density of secondary carbides precipitated from the matrix increases greatly with addition of Si from 0.5 to 1.5 wt.%, which is associated with more carbon and chromium elements confined in the matrix in the alloy containing 1.5 wt.%. More rod-like particles are observed in the alloy containing 0.5 wt.% Si, while the morphology of secondary carbides of alloy containing 1.5 wt.% is granular. The mechanical properties are improved with a 7% increase in tensile strength from 586 to 626 MPa and impact toughness from 5.8 to 7.3 J cm-2.

  18. Effect of Boron and Heat Treatment on Mechanical Properties of White Cast Iron for Mining Application%Effect of Boron and Heat Treatment on Mechanical Properties of White Cast Iron for Mining Application

    Institute of Scientific and Technical Information of China (English)

    Havva Kazdal Zeytin; Hakan Yildirim; Banu Berme; Selim Duduoglu; Gtirkan Kazdal; Adem Deniz

    2011-01-01

    Heat treatment methods were applied to white cast iron for improving the impact and wear resistance. Additionally, chemical composition optimization was made. Furthermore, the effect of boron addition on such applica- tions was investigated. Samples were investigated by using optical and electron microscope methods. Hardness, wear and impact tests were conducted. The results showed that the secondary carbides in the standard alloy were iron-enriched, needle-like carbides M3C when the boron-added alloy contained Fe23 (C, B)6 type, globular secondary carbides. It was concluded that heat treatment B provided higher wear and hardness properties, compared to the stand- ard heat treatment. Optimum mechanical properties were obtained by lower destabilisation temperatures and increasing temperature reduced the wear resistance and hardness.

  19. Psychometric Properties of the Mandarin Version of the Childhood Autism Spectrum Test (CAST): An Exploratory Study

    Science.gov (United States)

    Sun, Xiang; Allison, Carrie; Auyeung, Bonnie; Matthews, Fiona E.; Norton, Samuel; Baron-Cohen, Simon; Brayne, Carol

    2014-01-01

    Limited studies have investigated the latent autistic traits in the mainland Chinese population for autism spectrum conditions (ASC). This study explored the psychometric properties of a Mandarin Chinese version of the CAST in a sample consisting of 737 children in mainstream schools and 50 autistic cases. A combination of categorical data factor…

  20. Investigations of Properties of Wax Mixtures Used in the Investment Casting Technology – New Investigation Methods

    Directory of Open Access Journals (Sweden)

    J. Zych

    2012-09-01

    Full Text Available The results of testing of the selected group of wax mixtures used in the investment casting technology, are presented in the paper. Themeasurements of the kinetics of the mixtures shrinkage and changes of viscous-plastic properties as a temperature function wereperformed. The temperature influence on bending strength of wax mixtures was determined.

  1. Fractomechanical Properties of As-Cast and Austempered SG Cast Iron Between -40 °C and +20 °C

    Directory of Open Access Journals (Sweden)

    V.E. Fierro

    2002-06-01

    Full Text Available The spheroidal graphite (SG cast iron fractomechanical response varies with the test temperature and with the microstructure parameters. In the present paper, we analyze this variation performing fractomechanical tests in a temperature range from -40°C to +20°C, doing also Charpy and tensile tests for material characterization. The tests were carried out on as-cast samples and heat treated samples to obtain an ADI grade 1. In both cases, we studied samples taken from two well differentiated "Y" block sizes. The results obtained show that, for the chemical composition analyzed, both castings have a fractomechanical response decrease as the temperature diminishes. Besides, the block size enlargement produce a deterioration of the mechanical properties (the fracture toughness, mainly, for both castings.

  2. Welding and mechanical properties of cast FAPY (Fe-16 at. % Al-based) alloy slabs

    Energy Technology Data Exchange (ETDEWEB)

    Sikka, V.K.; Goodwin, G.M.; Alexander, D.J.; Howell, C.R.

    1995-08-01

    The low-aluminum-content iron-aluminum program deals with the development of a Fe-Al alloy with aluminum content such as a produce the minimum environmental effect at room temperature. The FAPY is an Fe-16 at. % Al-based alloy developed at the Oak Ridge National Laboratory as the highest aluminum-containing alloy with essentially no environmental effect. The chemical composition for FAPY in weight percent is: aluminum = 8.46, chromium = 5.50, zirconium = 0.20, carbon = 0.03, molybdenum = 2.00, yttrium = 0.10, and iron = 83.71. The cast ingots of the alloy can be hot worked by extrusion, forging, and rolling processes. The hot- worked cast structure can be cold worked with intermediate anneals at 800{degrees}C. Typical room-temperature ductility of the fine-grained wrought structure is 20 to 25% for this alloy. In contrast to the wrought structure, the cast ductility at room temperature is approximately 1% with a transition temperature of approximately 100 to 150{degrees}C, above which ductility values exceed 20%. The alloy has been melted and processed into bar, sheet, and foil. The alloy has also been cast into slabs, step-blocks of varying thicknesses, and shapes. The purpose of this section is to describe the welding response of cast slabs of three different thicknesses of FAPY alloy. Tensile, creep, and Charpy-impact data of the welded plates are also presented.

  3. Cast iron - a predictable material

    Directory of Open Access Journals (Sweden)

    Jorg C. Sturm

    2011-02-01

    Full Text Available High strength compacted graphite iron (CGI or alloyed cast iron components are substituting previously used non-ferrous castings in automotive power train applications. The mechanical engineering industry has recognized the value in substituting forged or welded structures with stiff and light-weight cast iron castings. New products such as wind turbines have opened new markets for an entire suite of highly reliable ductile iron cast components. During the last 20 years, casting process simulation has developed from predicting hot spots and solidification to an integral assessment tool for foundries for the entire manufacturing route of castings. The support of the feeding related layout of the casting is still one of the most important duties for casting process simulation. Depending on the alloy poured, different feeding behaviors and self-feeding capabilities need to be considered to provide a defect free casting. Therefore, it is not enough to base the prediction of shrinkage defects solely on hot spots derived from temperature fields. To be able to quantitatively predict these defects, solidification simulation had to be combined with density and mass transport calculations, in order to evaluate the impact of the solidification morphology on the feeding behavior as well as to consider alloy dependent feeding ranges. For cast iron foundries, the use of casting process simulation has become an important instrument to predict the robustness and reliability of their processes, especially since the influence of alloying elements, melting practice and metallurgy need to be considered to quantify the special shrinkage and solidification behavior of cast iron. This allows the prediction of local structures, phases and ultimately the local mechanical properties of cast irons, to asses casting quality in the foundry but also to make use of this quantitative information during design of the casting. Casting quality issues related to thermally driven

  4. High cycle fatigue properties of die-cast magnesium alloy AZ91D-1%MM

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The high cycle fatigue properties of the die-cast magnesium alloy AZ91D containing 1%mischmetal(mass fraction)at a fatigue ratio of 0.1 were investigated.The difference in the microstructure between the skin and core region of the die-cast magnesium alloy was analyzed by optical microscopy.The mechanical property tests indicate that the values of the tensile strength,elongation and hardness are 185 MPa,1.5%and HBS 70±3 at room temperature,respectively.The p-S-N curve(p=50%)of the die-cast magnesium alloy AZ91D-1%MM is determined and the mean fatigue strength corresponding to 3.8×105cycles is 70 MPa.A linear relation between S and Np in log scale between 103 and 106 cycles is written with a equation.The mechanical properties are influenced by the casting defects.The fatigue life of the samples with minor defects is near to the upper limit of the fatigue life data.The fatigue fracture surface of the samples with minor defects possesses the mixed characteristics of quasi-cleavage,lacerated ridge and dimple and it is briule fracture mode as a whole.

  5. Surface modification, microstructure and mechanical properties of investment cast superalloy

    OpenAIRE

    M. Zielińska; Kubiak, K.; J. Sieniawski

    2009-01-01

    Purpose: The aim of this work is to determine physical and chemical properties of cobalt aluminate (CoAl2O4) modifiers produced by different companies and the influence of different types of modifiers on the grain size, the microstructure and mechanical properties of high temperature creep resisting superalloy René 77.Design/methodology/approach: The first stage of the research work took over the investigations of physical and chemical properties of cobalt aluminate manufactured by three diff...

  6. Selected aspects of the piece production of iron alloy castings in terms of their environmental impact

    OpenAIRE

    Z. Maniowski; M. Młynski; Z. Sierant; Z. Żółkiewicz

    2010-01-01

    Problems of environmental protection are nowadays one of the top priorities in a policy programme adopted by the European Community.Reducing the negative impact of the domestic foundry industry on environment should result from complex and long-lasting activities,targeted not only at modernisation of the dust collecting units, but also at searches and implementation of alternative, innovative and more pro-ecology oriented means and techniques of casting manufacture. Reducing to minimum the le...

  7. Effect of titanium addition on structure and properties of the as-cast high Cr-Mo white iron

    Energy Technology Data Exchange (ETDEWEB)

    Ibrahim, Khaled M.; Nofal, Adel A. [Central Metallurgical R and D Institute (CMRDI), Helwan-Cairo (Egypt)

    2012-03-15

    This work analyses the wear behaviour and impact toughness of high Cr-Mo white irons alloyed with titanium as related to their microstructure and solidification path. Five alloys were used with different percentages of titanium (0, 0.47, 0.932, 1.31 and 1.78%). Such additions of titanium resulted in precipitation of small hard TiC particles in the austenitic matrix. These particles were well distributed in the matrix with Ti-additions up to 1.31% and then started to agglomerate with 1.78%Ti. Hardness increased dramatically with increasing amount of titanium addition. The wear behaviour was investigated for each alloy in the as-cast condition using the pin-on-ring configuration for 30 min against a ring made of SiC that rotated at a constant speed of 65 rpm. The wear test was performed under a load range of 30-180 N. The results are discussed in terms of microstructure and the minimum wear rate was obtained for the white cast iron alloyed with 1.31% titanium. The optimum tensile strength, impact toughness and wear resistance were also observed for the iron alloyed with 1.31% titanium. However, these properties started to deteriorate with further increase in titanium addition due to the clustering effect of titanium carbide particles in the austenitic matrix. Therefore, the optimum wear resistance and impact toughness of white cast iron under investigation (16% Cr-1.3% Mo-2.3% Ni) can be achieved by adding 1.31% titanium. (orig.)

  8. Influence of Composition on the Environmental Impact of a Cast Aluminum Alloy

    Directory of Open Access Journals (Sweden)

    Patricia Gómez

    2016-05-01

    Full Text Available The influence of alloy composition on the environmental impact of the production of six aluminum casting alloys (Al Si12Cu1(Fe, Al Si5Mg, Al Si9Cu3Zn3Fe, Al Si10Mg(Fe, Al Si9Cu3(Fe(Zn and Al Si9 has been analyzed. In order to perform a more precise environmental impact calculation, Life Cycle Assessment (LCA with ReCiPe Endpoint methodology has been used, with the EcoInvent v3 AlMg3 aluminum alloy dataset as a reference. This dataset has been updated with the material composition ranges of the mentioned alloys. The balanced, maximum and minimum environmental impact values have been obtained. In general, the overall impact of the studied aluminum alloys varies from 5.98 × 10−1 pts to 1.09 pts per kg, depending on the alloy composition. In the analysis of maximum and minimum environmental impact, the alloy that has the highest uncertainty is AlSi9Cu3(Fe(Zn, with a range of ±9%. The elements that contribute the most to increase its impact are Copper and Tin. The environmental impact of a specific case, an LED luminaire housing made out of an Al Si12Cu1(Fe cast alloy, has been studied, showing the importance of considering the composition. Significant differences with the standard datasets that are currently available in EcoInvent v3 have been found.

  9. Chemical bulk properties of multicrystalline silicon ingots for solar cells cast in silicon nitride crucibles

    Science.gov (United States)

    Modanese, C.; Di Sabatino, M.; Syvertsen, M.; Arnberg, L.

    2012-09-01

    Silicon nitride is an alternative material to the widely used silica crucibles for directional solidification of mc-Si ingots, its main advantages being the reusability in successive castings and elimination for a source for oxygen contamination of the ingot. In this work, several ingots were cast in these crucibles and compared to reference ingots cast in silica crucibles. The thermal properties of the Si3N4 crucible differ from those of the SiO2 crucible and lead to a different thermal history during melting and casting. The oxygen contamination of the ingot was observed to depend mainly on the melting and holding temperature, rather than on the crucible material. The lowest oxygen concentration was observed in the ingots with the lowest melting temperature. However, the thermal properties of the Si3N4 crucible influence the oxygen profile along ingot height, with a faster decrease in the concentration with increasing ingot height. This is believed to be due to a different mechanism for oxygen transport compared to that of the silica crucibles. The concentration of dopants in the ingots showed that contamination from the Si3N4 crucible occurred, probably due to diffusion of B- and P-oxides into the Si melt.

  10. Microstructure and mechanical properties of TiAl castings produced by zirconia ceramic mould

    Directory of Open Access Journals (Sweden)

    Tian Jing

    2011-11-01

    Full Text Available Owing to their low density and attractive high-temperature properties, gamma titanium aluminide alloys (TiAl alloys, hereafter have significant potential application in the aerospace and automobile industries, in which these materials may replace the heavier nickel-based superalloys at service temperatures of 600 – 900℃. Investment casting of TiAl alloys has become the most promising cost-effective technique for the manufacturing of TiAl components. Ceramic moulds are fundamental to fabricating the TiAl casting components. In the present work, ceramic mould with a zirconia primary coat was designed and fabricated successfully. Investment casting of TiAl blades and tensile test of specimens was carried out to verify the correctness and feasibility of the proposed method. The tensile test results indicate that, at room temperature, the tensile strength and the elongation are about 450 MPa and 0.8%, respectively. At 700℃, the tensile strength decreases to about 410 MPa and the elongation increases to 2.7%. Microstructure and mechanical properties of investment cast TiAl alloy are discussed.

  11. Microstructure and mechanical properties of magnesium alloy prepared by lost foam casting

    Institute of Scientific and Technical Information of China (English)

    TIAN Xue-feng; FAN Zi-tian; HUANG Nai-yu; WU He-bao; DONG Xuan-pu

    2005-01-01

    The microstructure and mechanical properties of AZ91 alloy prepared by lost foam casting(LFC) and various heat treatments have been investigated.The microstructure of the AZ91 alloy via LFC consists of dominant α-Mg and β-Mg17Al12 as well as a new phase Al32 Mn25 with size of about 5-50 μm,which has not been detected in AZ91 alloy prepared by other casting processes.The tests demonstrate that the as-cast mechanical properties are higher than those of sand gravity casting because of chilling and cushioning effect of foam pattern during the mould filling.The solution kinetics and the aging processes at different temperatures were also investigated by hardness and electrical resistivity measurements.The kinetics of aging are faster at the high temperature due to enhanced diffusion of atoms in the matrix,so the hardness peak at 380 ℃ occurs after 10 h;while at the lower aging temperature(150 ℃),the peak is not reached in the time(24 h) considered.

  12. Effect of Low Feed Rate FSP on Microstructure and Mechanical Properties of Extruded Cast 2285 Aluminum Alloy

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Friction stir processing (FSP), a variation of FSW (friction stir welding) is an emerging surface engineering technology that can locally eliminate casting defects and refine microstructures, thereby improving the mechanical properties of material. FSP can also produce fine grained microstructures through the thickness to impart superplasticity. The technology involves plunging a rapidly rotating, non consumable tool, comprising a profiled pin and larger diameter shoulder, into the surface and then traversing the tool across the surface. The pin and the shoulder friction heat the surface which alters the grain structure in the processed area thereby improving the mechanical properties. This paper presents the effects of FSP on microstructure and mechanical properties of extruded cast 2285 aluminum alloy at three different feed rates viz. 10, 12 and 15 mm/min. With the increase in the feed speed the material was observed to have increased impact strength. FSP also increased the tensile and yield strengths with increases in hardness and ductility values also. The observation has been listed in detail and pictorially represented.

  13. Effect of residual Al content on microstructure and mechanical properties of Grade B+Steel for castings for locomotives

    Directory of Open Access Journals (Sweden)

    Wang Kaifeng

    2013-11-01

    Full Text Available The bogie made of Grade B+ steel is one of the most important parts of heavy haul trains. Some accidents were found to be the result of fracture failure of the bogies. It is very important to find the reason why the fracture failure occurred. Because Al was added for the final deoxidation during the smelting process of the Grade B+Steel, residual Al existed to some extent in the castings. High residual Al content in the bogie casting was presumed to be the reason for the fracture. In this work, the influence of residual Al content in the range of 0.015wt.% to 0.3wt.% on the microstructure and mechanical properties of the Grade B+ Steel was studied. The experimental results showed that when the residual Al content is between 0.02wt.% and 0.20wt.%, the mechanical properties of the steel meet the requirements of technical specification for heavy haul train parts, and the fracture is typical plastic fractures. If the residual Al content is less than 0.02wt.%, the microstructures are coarse, and the mechanical properties can not meet the demand of bogie steel castings. When the residual Al content is more than 0.2wt.%, the elongation, reduction of area, and low-temperature impact energy markedly deteriorate. The fracture mode then changes from plastic fracture to cleavage brittle fracture. Therefore, the amount of Al addition for the final deoxidation during the smelting process must be strictly controlled. The optimum addition amount needs to be controlled within the range of 0.02wt.% to 0.20wt.% for the Grade B+Steel.

  14. Structure-property-processing correlations in freeze-cast composite scaffolds.

    Science.gov (United States)

    Hunger, Philipp M; Donius, Amalie E; Wegst, Ulrike G K

    2013-05-01

    Surprisingly few reports have been published, to date, on the structure-property-processing correlations observed in freeze-cast materials directionally solidified from polymer solutions, or ceramic or metal slurries. The studies that exist focus on properties of sintered ceramics, that is materials whose structure was altered by further processing. In this contribution, we report first results on correlations observed in alumina-chitosan-gelatin composites, which were chosen as a model system to test and compare the effect of particle size and processing parameters on their mechanical properties at a specific composition. Our study reveals that highly porous (>90%) hybrid materials can be manufactured by freeze casting, through the self-assembly of a polymer and a ceramic phase that occurs during directional solidification, without the need of additional processing steps such as sintering or infiltration. It further illustrates that the properties of freeze-cast hybrid materials can independently be tailored at two levels of their structural hierarchy, allowing for the simultaneous optimization of both mechanical and structural requirements. An increase in freezing rate resulted in decreases in lamellar spacing, cell wall thickness, pore aspect ratio and cross-sectional area, as well as increases in both Young's modulus and compressive yield strength. The mechanical properties of the composite scaffolds increased with an increasing particle size. The results show that both structure and mechanical properties of the freeze-cast composites can be custom-designed and that they are thus ideally suited for a large variety of applications that require high porosity at low or medium load-bearing capacity.

  15. Properties of Cross-Rolled Low Alloy White Cast Iron Grinding Ball

    Institute of Scientific and Technical Information of China (English)

    CHANG Li-min; LIU Lin; LIU Jian-hua

    2007-01-01

    The low-energy, multi-impact fracture resistance and the abrasiveness of the cross-rolled low alloy white cast iron grinding balls were studied after heat treatments at residual rolling temperature. Moreover, the means by which they are damaged and characters of the wear surface were analyzed. The results show that high resistance to impact fracture and high abrasiveness can be achieved after appropriate heat treatment at residual rolling temperature. This kind of heat treatment technology has several advantages under low impact and hard abrasive. These results are very useful for determining the optimized heat treatment technology at residual rolling temperatures.

  16. Effects of Magnetic Induction Intensity on Microstructure and Properties of Electromagnetic Centrifugal Casting High Cr Cast Iron%磁感应强度对电磁离心铸造高铬铸铁的影响

    Institute of Scientific and Technical Information of China (English)

    孙凯; 付拴拴; 张鸿雪

    2012-01-01

    为了提高高铬铸铁衬板的力学性能,使用电磁离心铸造浇注,并和常规重力离心铸造的试样进行了对比.结果表明,电磁离心铸造获得的试样组织明显细化,晶粒数量增多,晶粒尺寸细小,力学性能提高.当离心转速为1 500 r/min,磁感应强度为0.5T时,电磁离心铸造铸态试样的硬度(HRC)为55.3,冲击韧度为6.87 J/cm2;热处理后的硬度(HRC)为65.3,冲击韧度达到7.3 J/cm2.试样硬度比常规铸造试样提高了约10%,冲击韧度提高了约9%,相对耐磨性提高了约5%.%In order to improve mechanical properties ol the high chromium cast iron liner, the specimens were produced by electromagnetic centrifugal casting, and were comparatively analyzed with conventional casting specimens. The results show that microstructure of the electromagnetic centrifugal casting specimens is refined significantly, and grains are increased with the decrease of the grain size, evidently improving the mechanical properties of the specimens. With centrifugal velocity of 1 500 r/min and magnetic induction intensity of 0. 5 T, the hardness and impacting toughness of the electromagnetic centrifugal casting specimens reach HKC 55. 3 and 6. 87 J/cm2, respectively, and after heat treatment, hardness and impacting toughness reach HRC65. 3 and 7. 3 J/cm2 .respectively. Compared with those of the conventional casting ones, hardness, impacting toughness and relative wear resistance of the specimens prepared are increased by 10% , 8% and 5% , respectively.

  17. Preparation of YSZ solid electrolyte by slip casting and its properties

    Institute of Scientific and Technical Information of China (English)

    DOU Jing; LI Heping; XU Liping; ZHANG Lei; WANG Guangwei

    2009-01-01

    Fully stabilized YSZ solid electrolyte was prepared by slip casting. The density was measured according to the Archimedes principle and the linear shrinkage was calculated from measuring the sizes of samples before and after sintering. XRD analysis was conducted to verify the phase structure of both the starting YSZ powder and the prepared YSZ electrolyte. The microstructure of fracture surface and the electrical properties of the samples sintered at different temperatures were investigated via SEM and a complex impedance method, respectively. By comparison of the properties and features among the samples, a slip casting method was established to be a simple way to manufacture high-quality YSZ electrolyte at the sintering temperature of 1550℃ for 3 h, which provides a new approach for YSZ electrolyte with com-plex shapes and mass production.

  18. Effect of melting technology on the properties of G17CrMo5-5 steel for cast turbines

    Directory of Open Access Journals (Sweden)

    P. Mańkowski

    2010-10-01

    Full Text Available Two technologies of the G17CrMo 5-5 cast steel melting were compared, i.e. the so far used oxygen-recovery melting technology (electricarc furnace + ladle furnace – EAF + LF and a new recovery melting technology (electric induction furnace + ladle furnace - EIF + LF.The effect of the melting technology on the properties of cast steel for turbine parts was determined. The cast steel was evaluated in term of its metallurgical purity and mechanical properties. During melting of G17CrMo 5-5 steel in induction furnace, lower total content of oxygen in casting was reached, but nitrogen content was higher than it was in the cast steel from arc furnace. Metal refining in LF improved the steel desulphurising degree and contributed to modification of the non-metallic inclusions.

  19. Influence of Rare Earth Elements on Microstructure and Mechanical Properties of Cast High-Speed Steel Rolls

    Institute of Scientific and Technical Information of China (English)

    Wang Mingjia; Mu Songmei; Sun Feifei; Wang Yan

    2007-01-01

    The influence of rare earth (RE) elements on the solidification process and eutectic transformation and mechanical properties of the high-V type cast, high-speed steel roll was studied. Test materials with different RE additions were prepared on a horizontal centrifugal casting machine. The solidification process, eutectic structure transformation, carbide morphology, and the elements present, were all investigated by means of differential scanning calorimetry (DSC) and scanning electron microscopy energy dispersive spectrometry (SEM-EDS). The energy produced by crack initiation and crack extension was analyzed using a digital impact test machine. It was found that rare earth elements increased the tensile strength of the steel by inducing crystallization of earlier eutectic γ-Fe during the solidification process, which in turn increased the solidification temperature and thinned the dendritic grains. Rare earth elements with large atomic radius changed the lattice parameters of the MC carbide by forming rare earth carbides. This had the effect of dispersing long-pole MC carbides to provide carbide grains, thereby, reducing the formation of the gross carbide and making more V available, to increase the secondary hardening process and improve the hardness level. The presence of rare earth elements in the steel raised the impact toughness by changing the mechanism of MC carbide formation, thereby increasing the crack initiation energy.

  20. Structure and mechanical properties of improved cast stainless steels for nuclear applications

    Science.gov (United States)

    Kenik, E. A.; Busby, J. T.; Gussev, M. N.; Maziasz, P. J.; Hoelzer, D. T.; Rowcliffe, A. F.; Vitek, J. M.

    2017-01-01

    Casting of stainless steels is a promising and cost saving way of directly producing large and complex structures, such a shield modules or divertors for the ITER. In the present work, a series of modified high-nitrogen cast stainless steels has been developed and characterized. The steels, based on the cast equivalent of the composition of 316 stainless steel, have increased N (0.14-0.36%) and Mn (2-5.1%) content; copper was added to one of the heats. Mechanical tests were conducted with non-irradiated and 0.7 dpa neutron irradiated specimens. It was established that alloying by nitrogen significantly improves the yield stress of non-irradiated steels and the deformation hardening rate. Manganese tended to decrease yield stress but increased radiation hardening. The role of copper on mechanical properties was negligibly small. Analysis of structure was conducted using SEM-EDS and the nature and compositions of the second phases and inclusions were analyzed in detail. No ferrite formation or significant precipitation were observed in the modified steels. It was shown that the modified steels, compared to reference material (commercial cast 316L steel), had better strength level, exhibit significantly reduced elemental inhomogeneity and only minor second phase formation.

  1. Effect of microstructure on mechanical properties of a thin-walled cast duplex steel

    Energy Technology Data Exchange (ETDEWEB)

    Petzold, L.; Kreschel, T.; Peisker, D. [TU Bergakademie Freiberg, Institut fuer Eisen- und Stahltechnologie, Freiberg (Germany); Minnich, D. [Evosteel GmbH, Leipzig (Germany)

    2010-06-15

    The paper investigates the microstructure and the resulting mechanical properties of a duplex steel cast in sand dead-moulds. The chemical composition and the cooling rate are the main parameters affecting the properties. The chemical composition influences the thermodynamics of the phase transformation, the cooling rate determines the kinetics of formation of the microstructure. The latter varies with changes in wall thickness (investigated from 2 to 7 mm) and the position of the material within the casting. Through heat treatment, the composition of the microstructural components can be changed selectively afterwards, thereby the properties are improved. The correlation between microstructure and mechanical properties is explained quantitatively. Additionally to the austenite-ferrite ratio, the dispersion of microstructure has a large influence on the mechanical properties. Ranges of chemical composition and heat treatment parameters are identified where third phases, such as carbides and {sigma}-phase tend to occur. These influence the properties very sensitively even in small amounts. Finally, structural parameters are recognized that will lead to optimal combinations of properties. With an appropriate heat treatment technique, in particular the ductility properties are further increased. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  2. Development of a Cast Iron Fatigue Properties Database for use with Modern Design Methods

    Energy Technology Data Exchange (ETDEWEB)

    DeLa' O, James, D.; Gundlach, Richard, B.; Tartaglia, John, M.

    2003-09-18

    A reliable and comprehensive database of design properties for cast iron is key to full and efficient utilization of this versatile family of high production-volume engineering materials. A database of strain-life fatigue properties and supporting data for a wide range of structural cast irons representing industry standard quality was developed in this program. The database primarily covers ASTM/SAE standard structural grades of ADI, CGI, ductile iron and gray iron as well as an austempered gray iron. Twenty-two carefully chosen materials provided by commercial foundries were tested and fifteen additional datasets were contributed by private industry. The test materials are principally distinguished on the basis of grade designation; most grades were tested in a 25 mm section size and in a single material condition common for the particular grade. Selected grades were tested in multiple sections-sizes and/or material conditions to delineate the properties associated with a range of materials for the given grade. The cyclic properties are presented in terms of the conventional strain-life formalism (e.g., SAE J1099). Additionally, cyclic properties for gray iron and CGI are presented in terms of the Downing Model, which was specifically developed to treat the unique stress-strain response associated with gray iron (and to a lesser extent with CGI). The test materials were fully characterized in terms of alloy composition, microstructure and monotonic properties. The CDROM database presents the data in various levels of detail including property summaries for each material, detailed data analyses for each specimen and raw monotonic and cyclic stress-strain data. The CDROM database has been published by the American Foundry Society (AFS) as an AFS Research Publication entitled ''Development of a Cast Iron Fatigue Properties Database for Use in Modern Design Methods'' (ISDN 0-87433-267-2).

  3. Microstructure and Tensile Properties of Wrought Al Alloy 5052 Produced by Rheo-Squeeze Casting

    Science.gov (United States)

    Lü, Shulin; Wu, Shusen; Wan, Li; An, Ping

    2013-06-01

    The semisolid slurry of wrought Al alloy 5052 was prepared by the indirect ultrasonic vibration (IUV) method, in which the horn was vibrated under the outside of the metallic cup containing molten alloy, and then shaped by direct squeeze casting (SC). Spherical primary α-Al particles were uniformly dispersed in the matrix and presented a bimodal distribution of grain sizes. The effects of rheo-squeeze casting (RSC) parameters such as squeeze pressure and solid fraction on the microstructure and tensile properties of the semisolid alloy were investigated. The results indicate that average diameters of the primary α-Al particles decreased with the increase of squeeze pressure, while the tensile properties of the alloy increased. With the increase of solid fraction, the tensile strength increased first and then decreased, but the elongation decreased continuously. The best tensile properties were achieved when the slurry with a solid fraction of 0.17 solidified under 100 MPa. Compared to conventional squeeze casting, RSC process can offer the 5052 alloy better tensile strength and elongation, which were improved by 9.7 pct and 42.4 pct, respectively.

  4. Assessment the possibility of enhancing the tribological properties of the ferritic-austenitic cast steel

    Directory of Open Access Journals (Sweden)

    A. Brodziak

    2010-01-01

    Full Text Available The purpose of the research was to explore the possibility of enhancing the tribological properties of the ferritic-austenitic cast steel which is widely used in combustion gas desulphurization systems in the power industry. The subject of the research is the GX2CrNiMoN25-6-3 cast steel, a material for making pump rotors and other parts intended for operation at a temperature of up to 70°C in a water suspension containing Cl- and SO4-2 ions and sand / gypsum particles. It seems that in some applications, at low dynamics of parts’ operation and a predominance of erosive phenomena over corrosive ones, there is a potential for using the σ phase as a structural constitu-ent that enhances the tribological properties. However, due to the increased brittleness of the material, a need arises for optimizing the quantity of this phase and carrying out detailed research into the morphology of precipitates. To describe the tribological properties, the testing of the erosive and corrosive wear mechanism was used, which was carried out on a test stand of the authors' own construction. Metallographic and stereological examinations and hardness tests were performed, which enabled the understanding of the successive stages of tribological wear of the cast steel under investigation. The increasing volumetric share of the σ phase advantageously influenced the erosive wear resistance of the material.

  5. The evaluation of dynamic cracking resistance of chosen casting alloys in the aspect of the impact bending test

    Directory of Open Access Journals (Sweden)

    J.Sadowski

    2008-10-01

    Full Text Available The increase of quality and durability of produced casting alloys can be evaluated on the base of material tests performed on a high level. One of such modern test methods are tests of the dynamic damage process of materials and the evaluation on the base of obtained courses F(f, F(t of parameters of dynamic cracking resistance KId, JId, performed with the usage of instrumented Charpy pendulums. In the paper there was presented the evaluation of dynamic cracking resistance parameters of casting alloys such as: AK12 aluminum alloy, L20G cast steel and spheroid cast iron. The methodology of the evaluation of that parameters was described and their change as well, for the AK12 alloy with the cold work different level, L20G cast steel cooled from different temperatures in the range +20oC -60oC, and for the spheroid cast iron in different stages of treatment i.e. raw state, after normalization, spheroid annealing and graphitizing annealing.Obtained parameters of dynamic cracking resistance KId, JId of tested casting alloys enabled to define the critical value of the ad defect that can be tolerated by tested castings in different work conditions with impact loadings.

  6. Effect of Neodymium on As-Cast Microstructure and Mechanical Properties of AZ31 Wrought Alloy

    Institute of Scientific and Technical Information of China (English)

    Li Mingzhao; Fan Jinping; Zhang Junyuan; Liu Xuguang; Xu Bingshe

    2007-01-01

    Nd in the form of powder or intermediate alloy was added to AZ31 wrought alloy. The as-obtained alloy was characterized and tested with respect to its microstructure and mechanical properties. The relationship between the microstructure, mechanical properties and tensile fracture mechanism were discussed, with relevant alloys as reference for comparison. Experimental results show that the same quantity of Nd was added into AZ31 in powder form or in intermediate alloy, the absorption rate of Nd reached only 10.8% for the former case and as high as 95% for the later case. Pure Nd powder was added, no new compound was detected, but it served as reductant and purified alloy melt, resulting in improving the tensile strength while Nd was added into AZ31 as Mg-Nd intermediate alloy. The compound Al2Nd and Mg12 Nd were formed in magnesium alloy, which were distributed in the matrix in the shapes of strip and particle, evidently refined the as-cast structure. The as-cast tensile strength (228MPa) of adding pure Nd powder approximated to the figure (245MPa) of adding Mg-Nd intermediate alloy. The tensile fracture mchanism of as-cast AZ31 transformed from cleavage fracture into quasi-cleavage fracture.

  7. Effect of rheological properties of zircon-alumina suspensions on density of green casts

    Directory of Open Access Journals (Sweden)

    L.B. Garrido

    2001-10-01

    Full Text Available Rheological properties of aqueous suspensions (48 vol% of zircon-alumina mixtures containing different amounts of polyelectrolyte as dispersant were studied. Slip casting in a plaster mold and pressure filtration at 8 MPa experiments were performed to correlate the rheological properties of the suspensions with the relative density of green casts. Flow curves fitted satisfactorily to the Casson model. The Casson viscosity values remained nearly constant whereas Casson yield stress parameter decreased to a minimum and then increased with increasing the amount of dispersant added. The influence of particle size distribution (PSD of the powder mixtures on Casson yield stress parameter and on the minimum viscosity was also examined. Green densities increased as yield stress Casson parameter decreased. The mixture of alumina and zircon as fine and coarse powders produced bimodal PSD which maximized the green density of the compacts. Some weakly flocculated suspensions having low apparent viscosity and small yield stress produced casts with relatively high densification. This is attributed to a slight higher viscosity at low shear rates of these suspensions in which settling of particles and /or segregation of components can not occur.

  8. Tensile Properties of Al-Cu 206 Cast Alloys with Various Iron Contents

    Science.gov (United States)

    Liu, K.; Cao, X.; Chen, X.-G.

    2014-05-01

    The Al-Cu 206 cast alloys with varying alloy compositions ( i.e., different levels of Fe, Mn, and Si) were investigated to evaluate the effect of the iron-rich intermetallics on the tensile properties. It is found that the tensile strength decreases with increasing iron content, but its overall loss is less than 10 pct over the range of 0.15 to 0.5 pct Fe at 0.3 pct Mn and 0.3 pct Si. At similar iron contents, the tensile properties of the alloys with dominant Chinese script iron-rich intermetallics are generally higher than those with the dominant platelet phase. In the solution and artificial overaging condition (T7), the tensile strength of the 206 cast alloys with more than 0.15 pct Fe is satisfactory, but the elongation does not sufficiently meet the minimum requirement of ductility (>7 pct) for critical automotive applications. However, it was found that both the required ductility and tensile strength can be reached at high Fe levels of 0.3 to 0.5 pct for the alloys with well-controlled alloy chemistry and microstructure in the solution and natural aging condition (T4), reinforcing the motivation for developing recyclable high-iron Al-Cu 206 cast alloys.

  9. Effect of Titanium on the Mechanical Properties and Microstructure of Gray Cast Iron for Automotive Applications

    Science.gov (United States)

    Gelfi, M.; Gorini, D.; Pola, A.; La Vecchia, G. M.

    2016-09-01

    Lamellar gray cast iron, with a mainly pearlitic microstructure, is widely used in the automotive industry, mostly in the manufacturing of brake disks. This work analyzes in depth the effects of small variations of titanium content on the microstructure and mechanical properties of cast iron brake disks. For this purpose, eight different heats of EN-GJL-250 cast iron were selected, with a similar chemical composition but with different titanium contents, varying from 0.013 to 0.031%. The drops in mechanical strength and hardness values measured on the high-Ti samples were correlated to microstructural variations quantitatively observed by means of optical and scanning electron microscope. It was found that titanium combines to form titanium nitrides, suppressing the beneficial microstructural effects of nitrogen at solidification. Residual nitrogen, if present in sufficient quantity, promotes the nucleation of primary austenite from the liquid and the formation of a fine microstructure, with small eutectic cells and lower graphite content. Such a microstructure provides brake disks with better mechanical properties. The interpretation of results was further supported by thermal analysis and thermodynamic calculations.

  10. Effects of Moulding Sand Permeability and Pouring Temperatures on Properties of Cast 6061 Aluminium Alloy

    Directory of Open Access Journals (Sweden)

    Olawale Olarewaju Ajibola

    2015-01-01

    Full Text Available Effects of moulding sand permeabilities prepared from the combinations of four proportions of coarse and fine particle size mixtures and pouring temperatures varied from 700, 750, and 800 (±10°C were studied on the hardness, porosity, strength, and microstructure of cast aluminium pistons used in hydraulic brake master cylinder. Three sand moulds were prepared from each of the 80 : 20, 60 : 40, 40 : 60, and 20 : 80 ratios. The surfaces and microstructures of cast samples were examined using high resolution microscopic camera, metallurgical microscope with digital camera, and scanning electron microscope with EDX facilities. The best of the metallurgical properties were obtained from the combination of 80 : 20 coarse-fine sand ratio and 750 ± 10°C pouring temperature using as MgFeSi inoculant. An 8 : 25 ratio of coarse to fine grained eutectic aluminium alloy was obtained with enhanced metallographic properties. The cast alloy poured at 750 ± 1°C has a large number of fine grain formations assuming broom-resembling structures as shown in the 100 µm size SEM image.

  11. Microstructure and mechanical properties of high strength as-cast Ti-15-3 alloy

    Institute of Scientific and Technical Information of China (English)

    丁宏升; 周建中; 贾均; 郭景杰; 苏彦庆; 傅恒志

    2002-01-01

    The effects of heat treatment and solidification cooling rate on the microstructure and mechanical properties of as-cast Ti-15-3 alloy prepared by induction skull melting method were investigated. Results show that the microstructure of as-cast Ti-15-3 alloy changes from the features of simplified and larger size of beta grains to finer grain size with increasing solidification cooling rate. After solution treatment and different ageing treatment, alpha phase precipitates in grains interior as well as in grain boundaries. Due to the modification of the precipitate phase, the tensile strength and elongation of the alloy are improved simultaneously. A good combination of the values of 1.406GPa of σb and 4.5% of δ was obtained, which will be satisfied the use of this kind of alloy in critical areas.

  12. Effect of N on microstructure and mechanical properties of as-cast Ti-6Al alloy

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    In-situ titanium matrix composites with N content of 0. 045-0. 27 wt% have been produced by a casting method. The microstructure and mechanical properties of as-cast materials have been observed and tested.The results show that when N content in Ti-6Al alloy is between 0. 045 wt% and 0. 27 wt%, the reinforcement is a compound of Ti, Al and N, and volume fraction of reinforcements increases with an increase of N content.The hardness, compressive strength and elastic modulus are all higher than that of the matrix alloy. With the increase of N content, the compressive strength, the hardness and the elastic modulus increase. Fracture surface analysis has also shown that the matrix alloy fractures in a ductile model and the composites fracture in a cleavage brittle model with characteristics of dimple and cleavage surface.

  13. Effect of centrifugal counter-gravity casting on solidification microstructure and mechanical properties of A357 aluminum alloy

    Directory of Open Access Journals (Sweden)

    Li Xinlei

    2014-01-01

    Full Text Available To investigate the influence of Centrifugal Counter-gravity Casting (C3 process on the solidification microstructure and mechanical properties of the casting, A357 aluminum alloy samples were produced by different process conditions under C3. The results show that C3 has better feeding capacity compared with the vacuum suction casting; and that the mechanical vibration and the convection of melts formed at the centrifugal rotation stage suppress the growth of dendrites, subsequently resulting in the refinement of grains and the improvement of mechanical properties, density and hardness. A finer grain and higher strength can be obtained in the A357 alloy by increasing centrifugal radius and rotational speed. However, casting defects will appear near the rotational axis and the mechanical properties will decrease once the rotational speed exceeds 150 r·min-1.

  14. Thin Wall Iron Castings

    Energy Technology Data Exchange (ETDEWEB)

    J.F. Cuttino; D.M. Stefanescu; T.S. Piwonka

    2001-10-31

    Results of an investigation made to develop methods of making iron castings having wall thicknesses as small as 2.5 mm in green sand molds are presented. It was found that thin wall ductile and compacted graphite iron castings can be made and have properties consistent with heavier castings. Green sand molding variables that affect casting dimensions were also identified.

  15. Effect of RE-Al-N on Structures and Properties of M2 Cast High Speed Steel

    Institute of Scientific and Technical Information of China (English)

    符寒光; 杜建铭; 蒋志强; 邢建东

    2003-01-01

    M2 cast high speed steel was inoculated by addition of rare earth(RE)-Al-N, network eutectic carbides were eliminated, matrix microstructures were refined and the segregation of tungsten and molybdenum elements was relieved. In the condition that the hardness does not decrease, impact toughness obviously increases. Quenching at 1180 ℃ and three-times tempering at 560 ℃, the hardness of M2 cast high speed steel is 65~66 HRC, and impact toughness reaches 21.3 J*cm- 2. Modified M2 cast high speed steel has excellent thermal fatigue resistance and high temperature wear resistance. Roller made in modified M2 cast high speed steel has excellent service effect when it is used in slit rolling mill of hot rolling bar mill.

  16. The influence of the hardening conditions on the mechanical properties of ductile cast iron

    Directory of Open Access Journals (Sweden)

    T. Giętka

    2010-01-01

    Full Text Available Ductile cast iron has been austempered according to two variants. The first treatment variant was austenitizing at a temperature tγ = 830, 860 and 900 0C and holding at a temperature tpi = 400 and 300 0C for 8 ÷ 64 min. Second variant treatment was two-phase austenitizing. Firstly, it was heated at a temperature tγ = 950 0C and after forecooling and chilling at a temperature tγ’ = 900, 860 and 830 0C isothermal process was conducted in the same conditions as in the first variant. The cast iron with ferritic matrix was austempered. After hardening the mechanical (Rp0,2, Rm and plastic (A5 properties were examined as well as the microstructure of matrix and hardness. It was noticed that the heat treatment carried out according to variants I and II lead to attaining cast iron of grade: ADI EN-GJS-800-8, EN-GJS-1200-2, EN-GJS-1400-1 according to PN–EN 1564 : 2000; in addition, ductility of these grades was 1,5÷4 times bigger than the mini-mum standard material requirements.

  17. Effect of modifying process on mechanical properties of EN AC-43300 silumin cast into sand moulds

    Directory of Open Access Journals (Sweden)

    J. Pezda

    2009-07-01

    Full Text Available Significance of alloy modification in course of casting process is the most explicitly visible on example of Al-Si alloys. Broad application of these alloys in foundry industry has become possible after invention of a method which changes solidification form of Al-Si eutectic mixture. Such primarily thick, acicular shape of silicon crystals becomes changed into fine and compact structure due to introduction of a small quantity of modifier to liquid alloy. The paper presents an attempt of assessment of melting and modification with strontium effects on mechanical properties of EN AC-43300 alloy cast into sand moulds. Obtained results concern selection of optimal quantity of strontium additive in aspect of obtained mechanical properties (Rm, A5, KCV, HB. Effect of strontium additive on change of mechanical properties of the investigated alloy was presented in graphical form. Further investigations shall be connected with determination of an effect of strontium additive on mechanical properties of the alloy after solution heat treatment and ageing treatment.

  18. EFFECT OF La-RICH RE ON THE STRUCTURE AND PROPERTIES OF B319 ALLOY IN LOST FOAM CASTING

    Institute of Scientific and Technical Information of China (English)

    吴国华; 谢敏; 王叶双; 马春江; 朱燕萍; 丁文江

    2002-01-01

    By use of ICP spectroscopy, energy spectrum analysis, hydrogen tester, image analyzer, the differential scanning calorimetric (DSC) and microscope analysis, the effects of RE on the Porosity, structure and properties of B319 aluminum alloy were studied. The results show that under the 0. 3 C/s slow cooling rate in lost foam casting, the effect of RE on modification and grain size of B319 aluminum alloy is little. With the increase of RE master alloy, the tensile strength and elongation increase. When RE>0. 15%, block-like La2Si2Al3 phase appear, and the tensile strength and elongation decrease. The results also show that the melt hydrogen content and casting porosity can be decreased greatly by adding 0.15% RE to aluminum melt. This is the important reason why RE improves the mechanical properties of casting under lost foam casting condition.

  19. Effects of advanced oxidation on green sand properties via iron casting into green sand molds.

    Science.gov (United States)

    Wang, Yujue; Cannon, Fred S; Voigt, Robert C; Komarneni, Sridhar; Furness, J C

    2006-05-01

    The effects of advanced oxidation (AO) processing on the properties of green sand were studied via pouring cast iron into green sand molds. Upon cooling, the green sand molds were autopsied at various distances from the metal-sand interface. Autopsy green sand samples collected from a mold that incorporated AO water were characterized and compared to controlled samples collected from a similar autopsied mold made with conventional tap water (TAP). It was found that the AO processing removed a coating of coal pyrolysis products from the clay surface that typically accumulated on the clay surface. As a result, the AO-conditioned green sand retained 10-15% more active clay as measured bythe standard ultrasonic methylene blue titration than did the TAP-conditioned green sand. The AO processing also nearly doubled the generation of activated carbon from the normalized amount of coal composition of the green sand during the casting process. The AO-enhanced activated carbon generation and the AO-incurred clay surface cleaning provided the AO-conditioned green sand with higher normalized pore volume, and thus higher normalized m-xylene adsorption capacity, i.e., relative to before-metal-pouring conditions. Furthermore, mathematical analysis indicated that the AO-conditioned green sand better retained its important properties after pouring than did the TAP-conditioned green sand. Effectively, this meant after metal pouring, the AO-conditioned sample offered about the same net properties as the TAP-conditioned sample, even though the AO-conditioned sample contained less clay and coal before metal pouring. These results conformed to the full-scale foundry empirical finding that when AO is used, foundries need less makeup clay and coal addition through each casting cycle, and they release less air emissions.

  20. Effect of Phosphorus on Microstructure and High Temperature Properties of a Cast Ni-base Superalloy

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Effect of phosphorus on the microstructure and high temperature properties of a cast Ni-base superalloy M963 has been investigated. SEM observation and EDS analysis showed that P was mostly enriched in the interdendritic region, and the P-rich phase was formed in the front position of finally solidified eutectics in high P doped alloys. It was found that the P-rich phase, as preferred initiation and propagation site of cracks, could aggravate the fracture process at high temperature in high P doped alloys. Consequently, high P addition would reduce remarkably the ductility and creep life of M963 superalloy at high temperature.

  1. Effect of pore formers on properties of tape cast porous sheets for electrochemical flue gas purification

    DEFF Research Database (Denmark)

    Schmidt, Cristine Grings; Kammer Hansen, Kent; Andersen, Kjeld Bøhm

    2016-01-01

    permeability measurements, mercury porosimetry and pore orientation measurements, to investigate the role of the different pore formers on the properties after sintering at a temperature of 1250°C. Those tapes prepared from different non-spherical pore formers with comparable porosity of about 43%, showed...... significant differences in gas permeability which could be correlated to an increase in mean pore size and pore connectivity. The degree of pore orientation in the tape casting direction was determined by best-fit ellipse method and a modified linear intercept method and the obtained data were correlated...... with the corresponding gas permeability....

  2. Structure and properties of polypropylene cast films: Polymer type and processing effects

    Science.gov (United States)

    Mileva, Daniela; Gahleitner, Markus; Gloger, Dietrich

    2016-05-01

    The influence of processing parameters in a cast film extrusion process of thin films of isotactic polypropylene homopolymer and random propylene-ethylene copolymer was analyzed. Variation of the chill roll temperature allowed changing the supercooling of the melt and thus the generation of different crystal polymorphs of iPP. Additional focus was placed on the effect of flow induced crystallization via changing the output rate of the line. The crystal structure and morphology of the materials were evaluated and correlated to selected optical and mechanical properties.

  3. Effects of material variables and process parameters on properties of investment casting shells

    Science.gov (United States)

    Tumurugoti, Priyatham

    Manufacture of investment casting shells is a complex process. The choice of raw materials - refractory powders or grains, binders and additives - affects the properties of investment casting shells. In this study, different systems of shells were prepared, according to a design of experiments, with commercially available raw materials that differ in chemistry, particle size or particle size distribution. Shell strength was measured in green, fired and cooled, and hot conditions and the results were analyzed for strength -- material property relation. Various microstructures of polished cross sections of these shells were characterized using scanning electron microscope. It was determined that the amount of matrix holding the stucco grains was dominant factor affecting green strength. Fired and hot strengths were observed to vary depending on interactions between different phases of matrix and stucco. In addition to the material properties, control of shell building parameters is critical to achieve quality shells. Process parameters affect strength of the shell by providing a means to change the relative amounts of stucco, slurry and porosity. To study the microstructural variations, shells were prepared by varying process parameters like slurry viscosity and stucco size. Data from image analysis of different microstructures were correlated to their respective fired strengths. It was determined that the shells prepared from high viscosity slurry and fine stucco had the highest strength.

  4. Quantitative characterization of processing-microstructure-properties relationships in pressure die-cast magnesium alloys

    Science.gov (United States)

    Lee, Soon Gi

    The central goal of this research is to quantitatively characterize the relationships between processing, microstructure, and mechanical properties of important high-pressure die-cast (HPDC) Mg-alloys. For this purpose, a new digital image processing technique for automatic detection and segmentation of gas and shrinkage pores in the cast microstructure is developed and it is applied to quantitatively characterize the effects of HPDC process parameters on the size distribution and spatial arrangement of porosity. To get better insights into detailed geometry and distribution of porosity and other microstructural features, an efficient and unbiased montage based serial sectioning technique is applied for reconstruction of three-dimensional microstructures. The quantitative microstructural data have been correlated to the HPDC process parameters and the mechanical properties. The analysis has led to hypothesis of formation of new type of shrinkage porosity called, "gas induced shrinkage porosity" that has been substantiated via simple heat transfer simulations. The presence of inverse surface macrosegregation has been also shown for the first time in the HPDC Mg-alloys. An image analysis based technique has been proposed for simulations of realistic virtual microstructures that have realistic complex pore morphologies. These virtual microstructures can be implemented in the object oriented finite elements framework to model the variability in the fracture sensitive mechanical properties of the HPDC alloys.

  5. Effects of RE, V, Ti and B composite modification on the microstructure and properties of high chromium cast iron containing 3 % molybdenum

    Institute of Scientific and Technical Information of China (English)

    GUO Erjun; WANG Lihua; WANG Liping; HUANG Yongchang

    2009-01-01

    The effects of RE, V, Ti and B on the microstructure and properties of high chromium cast iron containing 3% molybdenum under as-cast and heat treatment conditions were investigated with the method of comparing experiments. The results show that with the increase of RE content, the primary austenite of high chromium east iron is obviously refined. The morphology of carbide is changed from netlike and lath to small multiangular isolated blocks or massive blocks, the isolated degree of carbide is improved obviously, and the size is significantly re-fined. The addition of V and B into high chromium cast iron can refine the microstructure, reduce coarse columnar crystals and make the carbide smaller and uniform. Through composite modification with RE, V, Ti and B, the hardness, wear resistance and impact toughness of high chromium cast iron are increased conspicuously. After heat treatment, the hardness of high chromium iron is increased significantly, but the toughness and wear resistance do not show great improvement.

  6. Structure-Property-Processing Correlations in Freeze-Cast Hybrid Scaffolds

    Science.gov (United States)

    Hunger, Philipp Malte

    Porous materials are highly sought after for applications ranging from catalyst carriers to tissue scaffolds. Most applications require clearly defined structural features and a specific mechanical performance. Therefore, it is essential to establish systematic structure-property-processing correlations to be able to tailor both structure and mechanical properties for a particular application. Because the introduction of porosity is detrimental to the mechanical performance of highly porous structures, it is necessary to generate a structure that allows for the mechanical properties to be maximized. One example for such a structure are honeycombs. In addition to the porosity and pore morphology, the scaffold's performance depends on the properties inherent to the material from which it is made. Polymeric foams possess high toughness but low stiffness, whereas ceramic foams possess high stiffness but low toughness. Natural composites like bone, antler and nacre have both high stiffness and high toughness. This unusual set of mechanical properties is thought to be intricately linked to the multi-level hierarchical composite structure present in these materials. Great potential for the fabrication of stiff, strong and tough porous scaffolds is thus seen in nacre-like composite materials with a hierarchical, honeycomb-like structure. Freeze casting is a method with which such hybrid materials can be made, adding the third dimension to nacre by forming a highly porous, hierarchical bulk material, with dense, nacre-like cell walls. The nacre-like cell walls self-assemble during the directional freezing of a water-based ceramic-polymer slurry. Reported here are structure-property-processing correlations observed in these materials. They are unusual, because they are, like nacre, solely glued by a polymeric phase and not processed further by sintering. The results illustrate several pathways to control both structure and mechanical properties in freeze-cast composites and

  7. Microstructure and properties of Ti–Nb–V–Mo-alloyed high chromium cast iron

    Indian Academy of Sciences (India)

    Youping Ma; Xiulan Li; Yugao Liu; Shuyi Zhou; Xiaoming Dang

    2013-10-01

    The correlations of microstructure, hardness and fracture toughness of high chromium cast iron with the addition of alloys (titanium, vanadium, niobium and molybdenum) were investigated. The results indicated that the as-cast microstructure changed from hypereutectic, eutectic to hypoeutectic with the increase of alloy contents. Mo dissolved in austenite and increased the hardness by solid solution strengthening. TiC and NbC mainly existed in austenite and impeded the austenite dendrite development. V existed in multicomponent systems in forms of V alloy compounds (VCrFe8 and VCr2C2).With the increase of alloy additions, carbides size changed gradually from refinement to coarseness, hardness and impact toughness were increased and then decreased. Compared with the fracture toughness (6 J/cm2) and hardness (50.8HRC) without any alloy addition, the toughness and hardness at 0.60 V–0.60Ti–0.60Nb–0.35Mo (wt%) additions were improved and achieved to 11 J/cm2 and 58.9HRC, respectively. The synergistic roles of Ti, Nb, V and Mo influenced the solidification behaviour of alloy. The refinement of microstructure and improvement of carbides morphologies, size and distribution improved the impact toughness.

  8. Characterization of Jatropha curcas L. Protein Cast Films with respect to Packaging Relevant Properties

    Directory of Open Access Journals (Sweden)

    Gabriele Gofferje

    2015-01-01

    Full Text Available There is increasing research ongoing towards the substitution of petrochemical based plastics by more sustainable raw materials, especially in the field of bioplastics. Proteins of different types such as whey, casein, gelatine, or zein show potential beyond the food and feed industry as, for instance, the application in packaging. Protein based coatings provide different packaging relevant properties such as barrier against permanent gases, certain water vapour barrier, and mechanical resistance. The aim of this study was to explore the potential for packaging applications of proteins from Jatropha curcas L. and to compare the performance with literature data on cast films from whey protein isolate. As a by-product from oil extraction, high amounts of Jatropha meal are obtained requiring a concept for its sustainable utilization. Jatropha seed cake includes up to 40% (w/w of protein which is currently not utilized. The present study provides new data on the potential of Jatropha protein for packaging applications. It was shown that Jatropha protein cast films show suitable barrier and mechanical properties depending on the extraction and purification method as well as on the plasticiser content. Based on these findings Jatropha proteins own potential to be utilized as coating material for food packaging applications.

  9. POROSITY AND STRENGTH PROPERTIES OF GYPSUM BONDED INVESTMENT USING TERENGGANU LOCAL SILICA FOR COPPER ALLOYS CASTING

    Directory of Open Access Journals (Sweden)

    S. Z. M. NOR

    2015-07-01

    Full Text Available In this study, several formulations of gypsum bonded investment (GBI as a mould for copper alloy casting has been developed and their properties had been investigated. The mould was developed using Terengganu local silica sand with the average particle size of 220–250 µm, acted as a refractory and Plaster of Paris (POP as a binder. The formulations used were 75% local silica, 25% plaster and various amounts (31–37% of water. The compressive strength, tensile strength, porosity, core hardness and mould hardness properties of the prepared GBI were studied. It has been found that both compressive strength and tensile strength reduced with a water content due to an increment of mould porosity which was confirmed via Scanning Electron Microscopy analysis. The mould hardness was found unchanged, but the core hardness was slightly reduced with the increment of water. The compressive strength of GBI moulds developed in this work was in the range of 600–1100 kN/m2, which was sufficient for copper alloy casting.

  10. Heat treatment of investment cast PH 13-8 Mo stainless steel: Part I. Mechanical properties and microstructure

    Science.gov (United States)

    Hochanadel, P. W.; Edwards, G. R.; Robino, C. V.; Cieslak, M. J.

    1994-04-01

    The microstructure of investment cast PH 13-8 Mo stainless steel heat-treated to various conditions was studied using light and electron microscopy, electron probe microanalysis, and Mössbauer spectroscopy. The mechanical properties were investigated by using uniaxial tensile testing, hardness testing, and Charpy impact testing. The Β-NiAl strengthening precipitates, though detectable by electron diffraction, were difficult to resolve by transmission electron microscopy (TEM) in specimens aged at low temperatures (566 °C and below). A high dislocation density was observed in the lath martensitic structure. The higher strength and lower ductility observed at low aging temperatures was attributed to both the high dislocation density and the precipitation of Β-NiAl. When samples were aged at high temperatures (> 566 °C), a lower dislocation density and a reverted austenite fraction on the order of 15 pct were observed. Spherical Β-NiAl precipitates were observed in the overaged condition. The decrease in strength and corresponding increase in ductility observed in samples aged at temperatures above 566 °C were attributed to the reverted austenite and recovery. Mechanical properties were improved when the homogenizing temperature and time were increased. Electron probe microanalysis quantified the increased homogeneity realized by increasing homogenizing temperature and time. Elimination of the refrigeration step, which normally follows the solution treatment, did not degrade the mechanical properties. Mössbauer spectroscopy showed only minor decreases in the fraction of retained austenite when refrigeration followed the solution treatment.

  11. Influence of waxes remelting used in investment casting on their thermal properties and linear shrinkage

    Directory of Open Access Journals (Sweden)

    K. Grzeskowiak

    2015-04-01

    Full Text Available This paper presents the results of thermal properties and linear shrinkage of jewelry waxes utilized in investment casting. Three types of jewelry waxes were cyclically processed (by heating, holding in a molten state and coolingin the temperature range between 25 and 90 °C for about 7 hours. The samples were tested after 5th, 10th and 15thcycle. The remelting was designed to simulate the process of waxes reusability for production of patterns. Changes in thermal properties of waxes were determined using differential scanning calorimetry (DSC and linear shrinkage values were specified. The conducted examinations allowed to establish the way of multiple utilization of waxes in producing precise models.

  12. Properties of casting solutions and ultrafiltration membranes based on fullerene-polyamide nanocomposites

    Directory of Open Access Journals (Sweden)

    N. N. Sudareva

    2012-03-01

    Full Text Available Poly(phenylene isophtalamide (PA was modified by fullerene C60 using solid-phase method. Novel ultrafiltration membranes based on nanocomposites containing up to 10 wt% of fullerene and carbon black were prepared. Properties of PA/C60 composites in solutions were studied by light scattering and rheological methods. The relationship between characteristics of casting solutions and properties of nanocomposite membranes was studied. Scanning electron microscopy was used for structural characterization of the membranes. It was found that increase in fullerene content in nanocomposite enhances the membrane rigidity. All nanocomposite membranes were tested in dynamic (ultrafiltration and static sorption experiments using a solution of protein mixture, with the purpose of studying protein sorption. The membranes modified by fullerene demonstrate the best values of flux reduced recovery after contact with protein solution. It was found that addition of fullerene C60 to the polymer improves technological parameters of the obtained composite membranes.

  13. Effect of fully and semi austempering treatment on the fatigue properties of ductile cast iron

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Min Gun; Lim, Bok Kyu; Hwang, Jung Gak [Kangwon National Univ., Chuncheon (Korea, Republic of); Kim, Dong Youl [Samcheok National Univ., Samcheok (Korea, Republic of)

    2005-03-01

    Single phase bainite structure which is obtained by the conventional austempering treatment reduces the ductility of ductile cast iron. Because of the reduction of ductility it is possible to worsen the fatigue properties. Therefore, semi austempered ductile iron which is treated from {alpha}+{gamma} is prepared to investigate the static strength and fatigue properties in comparison with fully austempered ductile iron (is treated from {gamma}). In spite of semi austempered ductile iron shows the 86% increase of ductility. Also, semi austempered ductile iron shows the higher fatigue limit and lower fatigue crack growth rate as compared with fully austempered ductile iron. By the fractographical analysis, it is revealed that the ferrite obtained by semi austempering process brings about the plastic deformation (ductile striation) of crack tip and gives the prior path of crack propagation. The relatively low crack growth rate in semi austempered specimen is caused by above fractographical reasons.

  14. Structure and mechanical properties of as-cast Ti–5Sn–xCr alloys

    Energy Technology Data Exchange (ETDEWEB)

    Hsu, Hsueh-Chuan; Wu, Shih-Ching; Hsu, Shih-Kuang [Department of Dental Technology and Materials Science, Central Taiwan University of Science and Technology, Taiwan, ROC (China); Institute of Biomedical Engineering and Materials Science, Central Taiwan University of Science and Technology, Taiwan, ROC (China); Chen, Chien-Yu [Advanced Materials and BioMaterials Laboratory, Department of Materials Science and Engineering, Da-Yeh University, 168 University Road, Dacun, Changhua 51591, Taiwan, ROC (China); Ho, Wen-Fu, E-mail: fujii@mail.dyu.edu.tw [Advanced Materials and BioMaterials Laboratory, Department of Materials Science and Engineering, Da-Yeh University, 168 University Road, Dacun, Changhua 51591, Taiwan, ROC (China)

    2014-06-01

    In this study, the effects of chromium (Cr) on the structure and mechanical properties of a Ti–5Sn-based system were examined, with an emphasis on improving the strength/modulus ratio. Commercially pure titanium (c.p. Ti) was used as a control. As-cast Ti–5Sn and a series of Ti–5Sn–xCr (x=1, 3, 5, 7, 9, 11 and 13 wt%) alloys prepared by using a commercial arc-melting vacuum-pressure casting system were investigated. X-ray diffraction (XRD) for phase analysis was conducted using a diffractometer. Three-point bending tests were performed on all specimens to evaluate their mechanical properties. The experimental results indicate that the structure and mechanical properties of these alloys changed with the addition of various amounts of Cr. The as-cast Ti–5Sn has a hexagonal α' phase. When 1 wt% Cr was introduced into the Ti–5Sn alloy, the structure essentially stayed the same. When the Cr content was at 3 wt%, retention of the metastable β phase began. When the Cr content was increased to 5 wt% or greater, the β phase was entirely retained. The ω phase was detected in Ti–5Sn–3Cr and Ti–5Sn–5Cr. Ti–5Sn–5Cr, which had the largest quantity of the ω phase, exhibited the highest microhardness value due to the hardening effect of the ω phase. Among all Ti–5Sn-based alloys, the β-phase Ti–5Sn–7Cr alloy had the lowest elastic modulus. It also exhibited higher bending strength/modulus ratios, which at 26.8 were higher than that of c.p. Ti (8.5) and that of Ti–6Al–4V (17.4). Furthermore, the elastically recoverable angle of this alloy (31.0°) was much greater than that of c.p. Ti (2.7°). In the search for better implant materials, the low modulus, ductile property, excellent elastic recovery capability and high strength/modulus ratio of β-phase Ti–5Sn–7Cr make this alloy a promising candidate.

  15. Y-chromosomal insights into the genetic impact of the caste system in India.

    Science.gov (United States)

    Zerjal, Tatiana; Pandya, Arpita; Thangaraj, Kumarasamy; Ling, Edmund Y S; Kearley, Jennifer; Bertoneri, Stefania; Paracchini, Silvia; Singh, Lalji; Tyler-Smith, Chris

    2007-03-01

    The caste system has persisted in Indian Hindu society for around 3,500 years. Like the Y chromosome, caste is defined at birth, and males cannot change their caste. In order to investigate the genetic consequences of this system, we have analysed male-lineage variation in a sample of 227 Indian men of known caste, 141 from the Jaunpur district of Uttar Pradesh and 86 from the rest of India. We typed 131 Y-chromosomal binary markers and 16 microsatellites. We find striking evidence for male substructure: in particular, Brahmins and Kshatriyas (but not other castes) from Jaunpur each show low diversity and the predominance of a single distinct cluster of haplotypes. These findings confirm the genetic isolation and drift within the Jaunpur upper castes, which are likely to result from founder effects and social factors. In the other castes, there may be either larger effective population sizes, or less strict isolation, or both.

  16. Evaluation of physical and mechanical properties of AZ91D/SiC composites by two step stir casting process

    Directory of Open Access Journals (Sweden)

    S. Aravindan

    2015-03-01

    Full Text Available Magnesium alloy (AZ91D composites reinforced with silicon carbide particle with different volume percentage were fabricated by two step stir casting process. The effect of changes in particle size and volume fraction of SiC particles on physical and mechanical properties of composites were evaluated under as cast and heat treated (T6 conditions. The experimental results were compared with the standard theoretical models. The results reveal that the mechanical properties of composites increased with increasing SiC particles and decrease with increasing particle size. Distribution of particles and fractured surface were studied through SEM and the presence of elements is revealed by EDS study.

  17. Microstructure, tensile properties and fracture behavior of high temperature Al–Si–Mg–Cu cast alloys

    Energy Technology Data Exchange (ETDEWEB)

    Mohamed, A.M.A., E-mail: madel@uqac.ca [Center for Advanced Materials, Qatar University, Doha (Qatar); Department of Metallurgical and Materials Engineering, Faculty of Petroleum and Mining Engineering, Suez Canal University, Box 43721, Suez (Egypt); Samuel, F.H. [Université du Québec à Chicoutimi, Chicoutimi, QC, Canada G7H 2B1 (Canada); Al Kahtani, Saleh [Industrial Engineering Program, Mechanical Engineering Department, College of Engineering, Salman bin Abdulaziz University, Al Kharj (Saudi Arabia)

    2013-08-10

    The high temperature tensile behavior of 354 aluminum cast alloy was investigated in the presence of Zr and Ni. The cast alloys were given a solutionizing treatment followed by artificial aging at 190 °C for 2 h. High temperature tensile tests were conducted at various temperatures from 25 °C to 300 °C. Optical microscopy and electron probe micro-analyzer were used to study the microstructure of different intermetallic phases formed. The fractographic observations of fracture surface were analyzed by scanning electron microscopy to understand the fracture mechanism. The results revealed that the intermetallics phases of (Al, Si){sub 3}(Zr, Ti), Al{sub 3}CuNi and Al{sub 9}NiFe are the main feature in the microstructures of alloys with Zr and Ni additions. The results also indicated that the tensile strength of alloy decreases with an increase in temperature. The combined addition of 0.2 wt% Zr and 0.2 wt% Ni leads to a 30% increase in the tensile properties at 300 °C compared to the base alloy. Zr and Ni bearing phases played a vital role in the fracture mechanism of the alloys studied.

  18. The influence of chromium on mechanical properties of austempered ductile cast iron

    Science.gov (United States)

    Bartosiewicz, L.; Singh, I.; Alberts, F. A.; Krause, A. R.; Putatunda, S. K.

    1995-02-01

    An investigation was carried out to examine the influence of microstructure and chromium on the tensile properties and plane strain fracture toughness of austempered ductile cast iron (ADI). The investigation also examined the growth kinetics of ferrite in these alloys. Compact tension and round cylindrical tensile specimens were prepared from ductile cast iron with Cr as well as without Cr. These specimens were then given four different heat treatments to produce four different microstructures. Tensile tests and fracture toughness tests were carried out as per ASTM standards E-8 and E-399. The crack growth mechanism during fracture toughness tests was also determined. The test results indicate that yield strength, tensile strength, and fracture toughness of ADI increases with an increase in the volume fractions of ferrite, and the fracture toughness reaches a peak when the volume fractions of the ferrite are approximately 60% in these alloys. The Cr addition was found to reduce the fracture toughness of ADI at lower hardness levels (<40 HRC); at higher hardness levels (≥40 HRC), the effect of chromium on the fracture toughness was negligible. The crack growth mechanism was found to be a combination of quasi-cleavage and microvoid coalescences, and the crack trajectories connect the graphite nodules along the way.

  19. 电磁离心铸造对高铬铸铁冲击韧度的影响%Influence of Electromagnetic Centrifugal Casting on High Chromium Casting Iron Impact Toughness

    Institute of Scientific and Technical Information of China (English)

    孙凯; 杨雪; 赵琳

    2012-01-01

    In order to improve the impact toughness of high chromium cast iron, centrifugal casting method was used on electromagnetic high chromium cast iron casting. The results show that the structure under electromagnetic centrifugal casting is refined; the number of grains increases; the grain size becomes smaller, the impact toughness and other mechanical performance are improved. When the centrifugal speed is 1800 r/min, the magnetic induction strength of 0.4T, the impact toughness after electromagnetic centrifugal casting cast is 6.9. Toughness increases compared with conventional samples.%为了提高高铬铸铁的冲击韧性,使用电磁离心铸造方法对高铬铸铁进行浇铸.结果表明:电磁离心铸造获得试样的组织明显细化,晶粒数量增多,晶粒尺寸变小,冲击韧度等力学性能提高.当离心转速为1800 r/min,磁感应强度为0.4T时,电磁离心铸造铸态试样的冲击韧度为6.9 J/cm2.冲击韧度较常规试样提高.

  20. SOLUTION TREATMENT EFFECT ON MICROSTRUCTURE AND MECHANICAL PROPERTIES OF AUTOMOTIVE CAST ALLOY

    Directory of Open Access Journals (Sweden)

    Eva Tillová

    2012-02-01

    Full Text Available The contribution describes influence of the heat treatment (solution treatment at temperature 545°C and 565°C with different holding time 2, 4, 8, 16 and 32 hours; than water quenching at 40°C and natural aging at room temperature during 24 hours on mechanical properties (tensile strength and Brinell hardness and microstructure of the secondary AlSi12Cu1Fe automotive cast alloy. Mechanical properties were measured in line with EN ISO. A combination of different analytical techniques (light microscopy, scanning electron microscopy (SEM were therefore been used for study of microstructure. Solution treatment led to changes in microstructure includes the spheroidization and coarsening of eutectic silicon. The dissolution of precipitates and the precipitation of finer hardening phase further increase the hardness and tensile strength of the alloy. Optimal solution treatment (545°C/4 hours most improves mechanical properties and there mechanical properties are comparable with mechanical properties of primary AlSi12Cu1Fe alloy. Solution treatment at 565 °C caused testing samples distortion, local melting process and is not applicable for this secondary alloy with 12.5 % Si.

  1. Thermal cooling effects in the microstructure and properties of cast cobalt-base biomedical alloys

    Science.gov (United States)

    Vega Valer, Vladimir

    Joint replacement prosthesis is widely used in the biomedical field to provide a solution for dysfunctional human body joints. The demand for orthopedic knee and hip implants motivate scientists and manufacturers to develop novel materials or to increase the life of service and efficiency of current materials. Cobalt-base alloys have been investigated by various researchers for biomedical implantations. When these alloys contain Chromium, Molybdenum, and Carbon, they exhibit good tribological and mechanical properties, as well as excellent biocompatibility and corrosion resistance. In this study, the microstructure of cast Co-Cr-Mo-C alloy is purposely modified by inducing rapid solidification through fusion welding processes and solution annealing heat treatment (quenched in water at room temperature. In particular the effect of high cooling rates on the athermal phase transformation FCC(gamma)↔HCP(epsilon) on the alloy hardness and corrosion resistance is investigated. The Co-alloy microstructures were characterized using metallography and microscopy techniques. It was found that the as cast sample typically dendritic with dendritic grain sizes of approximately 150 microm and containing Cr-rich coarse carbide precipitates along the interdendritic boundaries. Solution annealing gives rise to a refined microstructure with grain size of 30 microm, common among Co-Cr-Mo alloys after heat treating. Alternatively, an ultrafine grain structure (between 2 and 10 microm) was developed in the fusion zone for specimens melted using Laser and TIG welding methods. When laser surface modification treatments were implemented, the developed solidification microstructure shifted from dendritic to a fine cellular morphology, with possible nanoscale carbide precipitates along the cellular boundaries. In turn, the solidified regions exhibited high hardness values (461.5HV), which exceeds by almost 110 points from the alloy in the as-cast condition. The amount of developed athermal

  2. Effect of austempering parameters on microstructure and mechanical properties of horizontal continuous casting ductile iron dense bars

    Directory of Open Access Journals (Sweden)

    Chun-jie Xu

    2015-03-01

    Full Text Available In the present research, the orthogonal experiment was carried out to investigate the influence of different austempering process parameters (i.e. austenitizing temperature and time, and austempering temperature and time on microstructure and mechanical properties of LZQT500-7 ductile iron dense bars with 172 mm in diameter which were produced by horizontal continuous casting (HCC. The results show that the major factors influencing the hardness of austempered ductile iron (ADI are austenitizing temperature and austempering temperature. The fraction of retained austenite increases as the austenitizing and austempering temperatures increase. When austenitizing temperature is low, acicular ferrite and retained austenite can be efficiently obtained by appropriately extending the austenitizing time. The proper austmepering time could ensure enough stability of retained austenite and prevent high carbon austenite decomposition. The optimal mechanical properties of ADI can be achieved with the following process parameters: austenitizing temperature and time are 866 °C and 135 min, and austempering temperature and time are 279 °C and 135 min, respectively. The microstructure of ADI under the optimal austempering process consists of fine acicular ferrite and a small amount of retained austenite, and the hardness, tensile strength, yield strength, elongation and impact toughness of the bars are HBW 476, 1670 MPa, 1428 MPa, 2.93% and 25.7 J, respectively.

  3. Microstructures and creep properties of Mg-4Al-(1-4) La alloys produced by different casting techniques

    Energy Technology Data Exchange (ETDEWEB)

    Bai Jing, E-mail: baijing@seu.edu.cn [School of Materials Science and Engineering, Southeast University, Jiangning, Nanjing 211189, Jiangsu (China); Jiangsu Key Laboratory for Advanced Metallic Materials, Jiangning, Nanjing 211189, Jiangsu (China); Sun Yangshan; Xue Feng [School of Materials Science and Engineering, Southeast University, Jiangning, Nanjing 211189, Jiangsu (China); Jiangsu Key Laboratory for Advanced Metallic Materials, Jiangning, Nanjing 211189, Jiangsu (China); Qiang Jing [School of Materials Science and Engineering, Southeast University, Jiangning, Nanjing 211189, Jiangsu (China)

    2012-08-30

    The microstructures, mechanical properties and creep resistance of Mg-4Al-(1-4) La alloys produced by permanent mold casting and high pressure die casting (HPDC) were investigated. In addition to solute atoms in {alpha}-Mg matrix, Al element may exist in the form of three different intermetallic phases in the present alloys depending on the experimental conditions. In both casting states, the increase of La addition results in a rise in the volume fraction of Al{sub 11}La{sub 3} eutectic, and simultaneously Mg{sub 17}Al{sub 12} phase, including divorced eutectic in as-cast state and discontinuous precipitation after creep, is suppressed until completely disappears. This leads to a gradual increase in creep resistance. The formation of more Mg{sub 17}Al{sub 12} phase in HPDC alloys is considered a major factor in causing their worse creep properties by comparison with that of the permanent mold casting alloys when La content is in a lower level below 2 wt.%. By contrast, the HPDC alloys show better creep resistance with La content added above 2 wt.% owing to the formation of denser network distribution of Al{sub 11}La{sub 3} phase along grain/dendrite boundaries as a result of more rapid solidification rate and higher solidification pressure. For the alloys studied, grain/dendrite boundary sliding is suggested to be a possible controlling mechanism responsible for creep deformation at elevated temperatures.

  4. Property evaluations of dry-cast reconstituted bacterial cellulose/tamarind xyloglucan biocomposites.

    Science.gov (United States)

    de Souza, Clayton F; Lucyszyn, Neoli; Woehl, Marco A; Riegel-Vidotti, Izabel C; Borsali, Redouane; Sierakowski, Maria Rita

    2013-03-01

    We describe the mechanical defibrillation of bacterial cellulose (BC) followed by the dry-cast generation of reconstituted BC films (RBC). Xyloglucan (XGT), extracted from tamarind seeds, was incorporated into the defibrillated cellulose at various compositions, and new films were created using the same process. Microscopy and contact angle analyses of films revealed an increase in the microfibre adhesion, a reduced polydispersity in the diameters of the microfibrils and increased hydrophobic behaviour as a function of %XGT. X-ray diffraction analysis revealed changes to the crystallographic planes of the RBC and the biocomposite films with preferential orientation along the (110) plane. Compared with BC, RBC/XGT biocomposite with 10% XGT exhibited improvement in its thermal properties and in Young's modulus. These results indicated a reorganisation of the microfibres with mechanical treatment, which when combined with hydrocolloids, can create cellulose-based materials that could be applied as scaffolding for tissue engineering and drug release.

  5. Evaluation of Physical Properties of Wax Mixtures Obtained From Recycling of Patterns Used in Precision Casting

    Directory of Open Access Journals (Sweden)

    Biernacki R.

    2015-04-01

    Full Text Available The study investigated the properties of selected certified mixtures used to make wax patterns for the production of precision castings for the aerospace industry. In addition, an assessment of the recycled mixtures consisting of certified wax materials recovered during autoclaving was carried out. Hardness was tested via a proposed method based on penetration, creep related deformation, bending strength and linear contraction. The hardness was studied on laboratory specimens and patterns made with the use of injection molding equipment. For these patterns, linear contraction was estimated at variable pressure and for different temperature injection parameters. Deformations connected with creep and resistance were evaluated on cylindrical specimens. Differences in creep resistance in relation to the hardness were observed depending on the type of pattern mixtures. Recycled mixture has a greater resistance and smaller linear contraction than certified mixtures used for making sprue, raisers and other parts of filler system.

  6. Cast Iron And Mineral Cast Applied For Machine Tool Bed - Dynamic Behavior Analysis

    OpenAIRE

    2015-01-01

    Cast iron and mineral cast are the materials most often used in the machine structural elements design (bodies, housings, machine tools beds etc.). The materials significantly differ in physical and mechanical properties. The ability to suppress vibration is one of the most important factors determining the dynamic properties of the machine and has a significant impact on the machining capabilities of a machine tool. Recent research and development trends show that there is a clear tendency t...

  7. Microstructure and Mechanical Properties of Electromagnetic Centrifugal Cast 1Cr25Ni20Si2 Tube Blank

    Institute of Scientific and Technical Information of China (English)

    QIU Yi-qing; JIA Guang-lin; LIU Xiang-hua; WANG Guo-dong

    2006-01-01

    1Cr25Ni20Si2 tube blank centrifugally cast in a steady magnetic field was investigated. The results indicated that the solidification structure and the mechanical properties of the blank can be improved remarkably by electromagnetic stirring, and seamless tube can be manufactured from such blanks.

  8. STUDY OF MICROSTRUCTURE, HARDNESS AND WEAR PROPERTIES OF SAND CAST Cu-4Ni-6Sn BRONZE ALLOY

    Directory of Open Access Journals (Sweden)

    S. ILANGOVAN

    2015-04-01

    Full Text Available An alloy of Cu-4Ni-6Sn was cast in the sand moulds. The cast rods were homogenized, solution heat treated and aged for different periods of time. The specimens were prepared from the rods to study the microstructure, microhardness and wear properties. It was found that the aging process increases the hardness of the alloy significantly. It was due to the change in the microstructure of the alloy. Further, spinodal decomposition and the ordering reaction take place during the aging treatment. Specific wear rate was found to decrease with the hardness of the alloy. Coefficient of friction remains constant and is not affected by the aging process.

  9. Effect of melt conditioning on heat treatment and mechanical properties of AZ31 alloy strips produced by twin roll casting

    Energy Technology Data Exchange (ETDEWEB)

    Das, Sanjeev, E-mail: sanjeevdas80@gmail.com [The EPSRC Centre ‐ LiME, BCAST, Brunel University, Uxbridge UB8 3PH (United Kingdom); Barekar, N.S. [The EPSRC Centre ‐ LiME, BCAST, Brunel University, Uxbridge UB8 3PH (United Kingdom); El Fakir, Omer; Wang, Liliang [Department of Mechanical Engineering, Imperial College London, South Kensington Campus, London SW7 2AZ (United Kingdom); Prasada Rao, A.K.; Patel, J.B.; Kotadia, H.R.; Bhagurkar, A. [The EPSRC Centre ‐ LiME, BCAST, Brunel University, Uxbridge UB8 3PH (United Kingdom); Dear, John P. [Department of Mechanical Engineering, Imperial College London, South Kensington Campus, London SW7 2AZ (United Kingdom); Fan, Z. [The EPSRC Centre ‐ LiME, BCAST, Brunel University, Uxbridge UB8 3PH (United Kingdom)

    2015-01-03

    In the present investigation, magnesium strips were produced by twin roll casting (TRC) and melt conditioned twin roll casting (MC-TRC) processes. Detailed optical microscopy studies were carried out on as-cast and homogenized TRC and MC-TRC strips. The results showed uniform, fine and equiaxed grain structure was observed for MC-TRC samples in as-cast condition. Whereas, coarse columnar grains with centreline segregation were observed in the case of as-cast TRC samples. The solidification mechanisms for TRC and MC-TRC have been found completely divergent. The homogenized TRC and MC-TRC samples were subjected to tensile test at elevated temperature (250–400 °C). At 250 °C, MC-TRC sample showed significant improvement in strength and ductility. However, at higher temperatures the tensile properties were almost comparable, despite of TRC samples having larger grains compared to MC-TRC samples. The mechanism of deformation has been explained by detailed fractures surface and sub-surface analysis carried out by scanning electron and optical microscopy. Homogenized MC-TRC samples were formed (hot stamping) into engineering component without any trace of crack on its surface. Whereas, TRC samples cracked in several places during hot stamping process.

  10. Mechanical properties and microstructure of as-cast and extruded Mg-(Ce, Nd)-Zn-Zr alloys

    Institute of Scientific and Technical Information of China (English)

    YU Kun; LI Wen-xian; WANG Ri-chu

    2005-01-01

    Studies on the mechanical properties and microstructures of as-cast and extruded Mg-Ce-Zn-Zr and Mg-Nd-Zn-Zr alloys have been made before and after heat treatment. The results show that the mechanical properties of as-cast Mg-Ce and Mg-Nd alloys are as good as those of typical die cast AZ91 alloy and the heat resistant WE43 alloy. In Nd-containing alloys, the precipitated phase Mg12Nd contributes significantly to age hardening. The mechanical properties of extruded alloys are improved obviously compared with those of as-cast alloys. The ultimate strength is 257.8 MPa for extruded Mg-Ce alloy and 265.6 MPa for extruded Mg-Nd alloy. Extrusion is a useful method to improve both the strengths and elongations of the two experimental alloys at both ambient and elevated temperatures. The grain refinement and precipitation strengthening are the main strengthening mechanisms in the alloys. Tensile fracture surfaces show a dimple pattern after extruding and therefore reflect an improved elongation.

  11. Effect of pressure on microstructures and mechanical properties of Al-Cu-based alloy prepared by squeeze casting

    Institute of Scientific and Technical Information of China (English)

    ZHANG Ming; ZHANG Wei-wen; ZHAO Hai-dong; ZHANG Da-tong; LI Yuan-yuan

    2007-01-01

    A new high-strength aluminum alloy with better fluidity than that of ZL205A was developed. The effect of applied pressure during squeeze casting on microstructures and properties of the alloy was studied. The results show that the fluidity of the alloy is 16% and 21% higher than that of ZL205A at the pouring temperature of 993 K and 1 013 K, respectively. Compared with permanent-mold casting, mechanical properties of the alloy prepared by squeeze casting are much higher. The tensile strength and elongation of the alloy are 520 MPa and 7.9% in squeeze casting under an applied pressure of 75 MPa, followed by solution treatment at 763 K for 1 h and at 773 K for 8 h, quenching in water at normal temperature and aging at 463 K for 5 h. The improvement of mechanical properties is attributed to the remarkable decreasing of the secondary dendrite arm spacing(SDAS) and eliminating of micro-porosity in the alloy caused by applied pressure.

  12. Determination of physico-chemical properties of fine-grained waste from the cleaning of iron casting

    OpenAIRE

    2017-01-01

    In the European Union one of the most important activities is the recovery and recycling of waste including foundry waste. In the article waste arising from production of iron casting was presented. Selected physic-chemical properties of iron-bearing waste were defined. Opportunities of waste management are related to their chemical construction as well as some physical properties. On the basic the results of research the solutions of foundry waste management were proposed.

  13. Structure and properties of gray iron casted in the electromagnetic field

    Directory of Open Access Journals (Sweden)

    J. Szajnar

    2009-07-01

    Full Text Available In the national [1] and foreign [2] literature the methods of improving the homogeneity of the structure of castings using forced convection of the solidifying metal in the casting mould or the crystallizer are presented. This article presents the influence of chosen parameters of the rotating electromagnetic filed that is forcing the movement of melted metal in the mould on the morphology of graphite and the abrasive wear of the grey cast iron. The effect of this examination is the obtained modification of the flake graphite divisions morphology and a alteration of the abrasive wear resistance of the castings manufactured this way.

  14. Mechanical properties and microstructural analysis of an AgPd alloy cast under different temperatures

    OpenAIRE

    Olivieri, Karina Andrea Novaes; Faculdade de Odontologia de São José dos Campos - UNESP; Neisser, Maximiliano Piero; Bottino, Marco Antônio; Milton Edson MIRANDA; Wernek, Rafael Dario

    2010-01-01

    The metal restorations are used in Dentistry a long time ago. Nowadays we have resources that can get casting more accurate, with new material and equipments and techniques more precise. The purpose of this study was to evaluate the metallurgical and mechanical aspects of the AgPd dental alloy when it was submitted to different casting temperatures. It was used 30 specimens, divided in three groups (n=10): a) control group (no cast); b) casting temperature in accordance wi...

  15. Microstructure and mechanical properties of cast Mg-15Al-xNd alloy by permanent mold

    Directory of Open Access Journals (Sweden)

    Zhou Kangkang

    2013-09-01

    Full Text Available To improve the comprehensive mechanical properties of Mg-15Al magnesium alloy, different amounts (from 0 to 4.0wt.% of Nd were added to the alloy and six Mg-15Al-xNd alloys were prepared by metal mould casting. The effect of Nd content on microstructure of the alloys was investigated by means of OM, SEM, EDS, TEM, and XRD. The tensile properties were tested at room temperature (RT and high temperature (473 K. The results indicate that the primary α-Mg dendrite is significantly refined with the addition of Nd. The best refinement is reached at 1.0wt.% Nd content and the average dendrite arm spacing decreases from 80-100 μm (without Nd addition to ~20 μm. A further increase in Nd content leads to the coarsening of the primary α-Mg dendrite. The addition of Nd improves the tensile properties of Mg-15Al both at RT and 473 K. The Mg-15Al alloy containing 1.0wt.% Nd exhibits the best tensile properties. Compared with the alloy without Nd, the yield and ultimate tensile strength of the Mg-15Al-1.0Nd alloy at RT increase from 132.3 to 148.6 MPa and 152.3 to 189.6 MPa, increase by 12.3% and 24.5%, respectively; and the elongation at RT increases from 0.05 % to 1.24%. The yield and tensile strength of the alloy at 473 K increase from 97.9 to 115.3 MPa and 121.6 to 140.1 MPa, increase by 15.2% and 20%, respectively. Further increment of Nd content to 1.5wt.% degrades the tensile properties, which is ascribed to grain coarsening and growth of the Al-Nd phase.

  16. Aging properties of films of plasticized vital wheat gluten cast from acidic and basic solutions.

    Science.gov (United States)

    Olabarrieta, Idoia; Cho, Sung-Woo; Gällstedt, Mikael; Sarasua, Jose-Ramon; Johansson, Eva; Hedenqvist, Mikael S

    2006-05-01

    In order to understand the mechanisms behind the undesired aging of films based on vital wheat gluten plasticized with glycerol, films cast from water/ethanol solutions were investigated. The effect of pH was studied by casting from solutions at pH 4 and pH 11. The films were aged for 120 days at 50% relative humidity and 23 degrees C, and the tensile properties and oxygen and water vapor permeabilities were measured as a function of aging time. The changes in the protein structure were determined by infrared spectroscopy and size-exclusion and reverse-phase high-performance liquid chromatography, and the film structure was revealed by optical and scanning electron microscopy. The pH 11 film was mechanically more stable with time than the pH 4 film, the latter being initially very ductile but turning brittle toward the end of the aging period. The protein solubility and infrared spectroscopy measurements indicated that the protein structure of the pH 4 film was initially significantly less polymerized/aggregated than that of the pH 11 film. The polymerization of the pH 4 film increased during storage but it did not reach the degree of aggregation of the pH 11 film. Reverse-phase chromatography indicated that the pH 11 films were to some extent deamidated and that this increased with aging. At the same time a large fraction of the aged pH 11 film was unaffected by reducing agents, suggesting that a time-induced isopeptide cross-linking had occurred. This isopeptide formation did not, however, change the overall degree of aggregation and consequently the mechanical properties of the film. During aging, the pH 4 films lost more mass than the pH 11 films mainly due to migration of glycerol but also due to some loss of volatile mass. Scanning electron and optical microscopy showed that the pH 11 film was more uniform in thickness and that the film structure was more homogeneous than that of the pH 4 film. The oxygen permeability was also lower for the pH 11 film. The

  17. Influence of titanium diboride reinforcements on the microstructure, mechanical properties and fracture behavior of cast zinc-aluminum composites

    Science.gov (United States)

    Dionne, Sylvie

    The objective of the present study was to examine the relationships between the microstructure, mechanical properties and failure mechanisms which control the performance of TiB2 particle reinforced Zn-8 wt.% Al (ZA-8) composites. Unreinforced ZA-8 and four composite heats with nominal particle contents of 5, 10, 20 and 30 vol.% were prepared using stir casting and permanent mold casting techniques. Tensile, compression, Charpy impact and short bar chevron-notch fracture toughness tests were conducted at room temperature. The microstructure and fracture surfaces of the specimens were characterized using optical, scanning electron, transmission electron and focused ion beam microscopy. These experimental results were compared with relevant MMC models and with published data on Zn-based composites. The TiB2/ZA-8 composites had a homogeneous distribution of particles in a matrix similar to unreinforced ZA-8. The matrix grain size decreased as the TiB2 content increased. No interfacial reaction products were detected. A good correlation was obtained between the measured composite stiffness and the values predicted using an Eshelby model. The yield strength and work hardening rate of TiB2/ZA-8 were only marginally higher than those of unreinforced ZA-8. The strength properties did not increase with the particle content as predicted by the Eshelby model. The premature activation of relaxation processes limited the extent to which particle reinforcement improved the strength of the ZA-8 matrix. Temperature-activated relaxation processes such as diffusion and dislocation motion can occur readily in ZA-8 at room temperature, which corresponds to 0.44 TM. Particle reinforcement of the ZA-8 alloy produced a degradation of the toughness which was sensitive to the loading rate. The Charpy energy of TiB 2/ZA-8 was up to 85% smaller than that of ZA-8, while the corresponding loss in fracture toughness was only 15%. The moderate fracture toughness decrease was explained by the

  18. Regularization Method to the Parameter Identification of Interfacial Heat Transfer Coefficient and Properties during Casting Solidification

    Institute of Scientific and Technical Information of China (English)

    SUI Da-shan; CUI Zhen-shan

    2007-01-01

    The accurate material physical properties, initial and boundary conditions are indispensable to the numerical simulation in the casting process, and they are related to the simulation accuracy directly.The inverse heat conduction method can be used to identify the mentioned above parameters based on the temperature measurement data.This paper presented a new inverse method according to Tikhonov regularization theory.A regularization functional was established and the regularization parameter was deduced, the Newton-Raphson iteration method was used to solve the equations.One detailed case was solved to identify the thermal conductivity and specific heat of sand mold and interfacial heat transfer coefficient (IHTC) at the meantime.This indicates that the regularization method is very efficient in decreasing the sensitivity to the temperature measurement data, overcoming the illposedness of the inverse heat conduction problem (IHCP) and improving the stability and accuracy of the results.As a general inverse method, it can be used to identify not only the material physical properties but also the initial and boundary conditions' parameters.

  19. Properties of cast films from hemp (Cannabis sativa L.) and soy protein isolates. A comparative study.

    Science.gov (United States)

    Yin, Shou-Wei; Tang, Chuan-He; Wen, Qi-Biao; Yang, Xiao-Quan

    2007-09-05

    The properties of cast films from hemp protein isolate (HPI) including moisture content (MC) and total soluble mass (TSM), tensile strength (TS) and elongation at the break (EAB), and surface hydrophobicity were investigated and compared to those from soy protein isolate (SPI). The plasticizer (glycerol) level effect on these properties and the interactive force pattern for the film network formation were also evaluated. At some specific glycerol levels, HPI films had similar MC, much less TSM and EAB, and higher TS and surface hydrophobicity (support matrix side), as compared to SPI films. The TS of HPI and SPI films as a function of plasticizer level (in the range of 0.3-0.6 g/g of protein) were well fitted with the exponential equation with coefficient factors of 0.991 and 0.969, respectively. Unexpectedly, the surface hydrophobicity of HPI films (including air and support matrix sides) increased with increasing the glycerol level (from 0.3 to 0.6 g/g of protein). The analyses of protein solubility of film in various solvents and free sulfydryl group content showed that the disulfide bonds are the prominent interactive force in the HPI film network formation, while in the SPI case, besides the disulfide bonds, hydrogen bonds and hydrophobic interactions are also to a similar extent involved. The results suggest that hemp protein isolates have good potential to be applied to prepare protein film with some superior characteristics, e.g., low solubility and high surface hydrophobicity.

  20. The Effect of Iron Content on Microstructure and Mechanical Properties of A356 Cast Alloy

    Science.gov (United States)

    Tunçay, Tansel; Bayoğlu, Samet

    2017-04-01

    In the present study, microstructure and mechanical properties of A356 alloy including various amounts (0.2 to 1.2 wt pct) of iron were investigated. The alloys were produced by conventional gravity sand casting method. In order to determine the effect of iron addition to A356, optical and scanning electron microscopes (SEM/EDS) were used for microstructural examinations, and X-ray diffraction (XRD) analysis was carried out for phase characterization. Tensile tests were also conducted in order to determine effect of the Fe content on mechanical properties. It was found that as the Fe content of A356 was increased, the secondary dendrite arm spacing (SDAS) was decreased and the morphology of Al-Si eutectic became finer. From XRD examinations, different iron-based intermetallic compounds ( β-Al5FeSi and α-Al8Fe2Si) formations were observed. It was also observed that as iron content increased, α-Al8Fe2Si intermetallic was transformed into β-Al5FeSi intermetallic. The tensile test results revealed that tensile strength and elongation values were reduced by increasing Fe content. It was also determined that β-Al5FeSi intermetallics were more negatively effective on tensile strength than α-Al8Fe2Si intermetallics.

  1. The Effect of Iron Content on Microstructure and Mechanical Properties of A356 Cast Alloy

    Science.gov (United States)

    Tunçay, Tansel; Bayoğlu, Samet

    2017-01-01

    In the present study, microstructure and mechanical properties of A356 alloy including various amounts (0.2 to 1.2 wt pct) of iron were investigated. The alloys were produced by conventional gravity sand casting method. In order to determine the effect of iron addition to A356, optical and scanning electron microscopes (SEM/EDS) were used for microstructural examinations, and X-ray diffraction (XRD) analysis was carried out for phase characterization. Tensile tests were also conducted in order to determine effect of the Fe content on mechanical properties. It was found that as the Fe content of A356 was increased, the secondary dendrite arm spacing (SDAS) was decreased and the morphology of Al-Si eutectic became finer. From XRD examinations, different iron-based intermetallic compounds (β-Al5FeSi and α-Al8Fe2Si) formations were observed. It was also observed that as iron content increased, α-Al8Fe2Si intermetallic was transformed into β-Al5FeSi intermetallic. The tensile test results revealed that tensile strength and elongation values were reduced by increasing Fe content. It was also determined that β-Al5FeSi intermetallics were more negatively effective on tensile strength than α-Al8Fe2Si intermetallics.

  2. Utilization of En Ac-42100 Cast Aluminum Alloy for Casting of Critical Components. I. Preparation and Mechanical Properties

    Directory of Open Access Journals (Sweden)

    Vanko Branislav

    2014-12-01

    Full Text Available Requirement on the minimum value of elongation for critical components is about 15 %. The research deals with the possibility of replacing the dendritic morphology of primary solid solution and brittle eutectic silicon plates with finer particles with a more suitable morphology and size, and the possibility of increasing the mechanical properties. Introduced first part is focused on the process of preparation of experimental material and mechanical properties.

  3. Effect of Discontinuous Ultrasonic Treatment on Mechanical Properties and Microstructure of Cast Al413-SiCnp Nanocomposites

    Directory of Open Access Journals (Sweden)

    M.R. Dehnavi

    2015-05-01

    Full Text Available Effects of discontinuous ultrasonic treatment on the microstructure, nanoparticle distribution, and mechanical properties of cast Al413-SiCnp nanocomposites were studied. The results showed that discontinuous ultrasonic treatment was more effective in improving the mechanical properties of the cast nanocomposites than the equally timed continuous treatment. The yield and ultimate tensile strengths of Al413-2%SiCnp nanocomposites discontinuously treated for two 20 minute periods increased by about 126% and 100% compared to those of the monolithic sample, respectively. These improvements were about 107% and 94% for the nanocomposites continuously treated for a single 40 minute period. The improvement in the mechanical properties was associated with severe refinement of the microstructure, removal of the remaining gas layers on the particles surfaces, more effective fragmentation of the remaining agglomerates as well as improved wettability and distribution of the reinforcing particles during the first stage of solidification.

  4. Study of rare earth element effect on microstructures and mechanical properties of an Al-Cu-Mg-Si cast alloy

    Institute of Scientific and Technical Information of China (English)

    WAN Weiwei; HAN Jianmin; LI Weijing; WANG Jinhua

    2006-01-01

    The improvements of microstructures and properties of a high strength aluminum cast alloy were studied.The effects of rare earth elements on the microstructures and mechanical properties of the high strength cast alloy Al-Cu-Mg-Si were investigated.The result shows that the addition of rare earth elements can change the microstructures in refining the grain size of the alloy and making the needle-like and laminar eutectic Si to a granular Si.With the increase of the rare earth, the tensile strength and elongation of the alloy increase first and then fall down.The mechanical properties of the alloy will reach the highest value when the content of rare earth elements is about 0.7%.

  5. Microstructure And Mechanical Properties Of An Al-Zn-Mg-Cu Alloy Produced By Gravity Casting Process

    Directory of Open Access Journals (Sweden)

    Saikawa S.

    2015-06-01

    Full Text Available High-strength aluminum alloy are widely used for structural components in aerospace, transportation and racing car applications. The objective of this study is to enhance the strength of the Al-Zn-Mg-Cu alloy used for gravity casting process. All alloys cast into stepped-form sand mold (Sand-mold Casting; SC and Y-block shaped metal mold(Permanent mold Casting; PC C and then two –step aged at 398-423 K after solution treated at 743 K for 36 ks. The tensile strength and total elongation of the two-step aged SC alloys were 353-387 MPa and about 0.4% respectively. This low tensile properties of the SC alloys might be caused by remaining of undissolved crystallized phase such as Al2CuM, MgZn2 and Al-Fe-Cu system compounds. However, good tensile properties were obtained from PC alloys, tensile strength and 0.2% proof stress and elongation were 503-537 MPa, 474-519 MPa and 1.3-3.3%.

  6. Displaying structural property and inheritance of cast iron surfacing on steel base

    Science.gov (United States)

    Shveev, I. A.

    2016-06-01

    Graphite inclusions heredity in deposited layer from remelted special cast iron billets was established. The possibility of controlling the structural state and the quality of the deposited layer due to technological parameters of welding and heat treatment of parts is shown. Ways of improving cast iron wear resistance durability are proposed.

  7. 电磁离心铸造对高铬铸铁性能的影响%Effects of Electromagnetic Centrifugal Casting on Properties of High Chromium Cast Iron

    Institute of Scientific and Technical Information of China (English)

    孙凯; 宋世明; 李壮

    2012-01-01

    In order to improve the mechanical properties of the high chromium cast iron, electromagnetic centrifugal casting method of the casting specimen was carried out experimentally to compare the conventional casting. The results show that after electromagnetic centrifugal casting, samples structure is refined, grains quantity increase; the grain size get smaller; mechanical properties increase. When the centrifugal speed is 1500r/min, magnetic induction of 0.5T, the electromagnetic centrifugal casting hardness of cast specimens is 55.3HRC, the hardness of 65.3HRC after heat treatment. Hardness increases by 10% than conventional cast samples, relative wear resistance P of cast sample is improved 5% than that of the conventional methods treated.%为了提高高铬铸铁衬板的力学性能,本实验使用电磁离心铸造方法进行试样浇铸,同常规浇铸的试样进行比对.结果表明:电磁离心铸造获得试样的组织明显细化,晶粒数量增多,晶粒尺寸变小,力学性能提高.当离心转速为1500r/min,磁感应强度为0.5T时,电磁离心铸造铸态试样的硬度为55.3 HRC,热处理后硬度为65.3 HRC.铸造硬度较常规试样提高10%,相对耐磨性β较常规浇铸试样提高5%.

  8. Creep and residual mechanical properties of cast superalloys and oxide dispersion strengthened alloys

    Science.gov (United States)

    Whittenberger, J. D.

    1981-01-01

    Tensile, stress-rupture, creep, and residual tensile properties after creep testing were determined for two typical cast superalloys and four advanced oxide dispersion strengthened (ODS) alloys. The superalloys examined included the nickel-base alloy B-1900 and the cobalt-base alloy MAR-M509. The nickel-base ODS MA-757 (Ni-16CR-4Al-0.6Y2O3 and the iron-base ODS alloy MA-956 (Fe-20Cr-5Al-0.8Y2O3) were extensively studied, while limited testing was conducted on the ODS nickel-base alloys STCA (Ni-16Cr-4.5Al-2Y2O3) with a without Ta and YD-NiCrAl (Ni-16Cr-5Al-2Y2O3). Elevated temperature testing was conducted from 114 to 1477 K except for STCA and YD-NiCrAl alloys, which were only tested at 1366 K. The residual tensile properties of B-1900 and MAR-M509 are not reduced by prior creep testing (strains at least up to 1 percent), while the room temperature tensile properties of ODS nickel-base alloys can be reduced by small amounts of prior creep strain (less than 0.5 percent). The iron-base ODS alloy MA-956 does not appear to be susceptible to creep degradation at least up to strains of about 0.25 percent. However, MA-956 exhibits unusual creep behavior which apparently involves crack nucleation and growth.

  9. Microstructure and Mechanical Properties of Al356/SiCp Cast Composites Fabricated by a Novel Technique

    Science.gov (United States)

    Amirkhanlou, Sajjad; Niroumand, Behzad

    2013-01-01

    In this study, SiCp containing composite powders were used as the reinforcement carrier media for manufacturing cast Al356/5 vol.% SiCp composites. Untreated SiCp, milled particulate Al-SiCp composite powder, and milled particulate Al-SiCp-Mg composite powder were injected into Al356 melt. The resultant composite slurries were then cast from either a fully liquid state (stir casting) or semisolid state (compocasting). The results revealed that by injection of composite powders, the uniformity of the SiCp in the Al356 matrix was greatly improved, the particle-free zones in the matrix were disappeared, the SiC particles became smaller, the porosity was decreased, and the matrix microstructure became finer. Compocasting changed the matrix dendritic microstructure to a finer non-dendritic one and also slightly improved the distribution of the SiCp. Simultaneous utilization of Al-SiCp-Mg composite powder and compocasting method increased the macro- and micro-hardness, impact energy, bending strength, and bending strain of Al356/SiCp composite by 35, 63, 20, 20, and 40%, respectively, as compared with those of the composite fabricated by injection of untreated SiCp and stir casting process.

  10. Comparison of environmental impacts of building structures with in situ cast floors and with precast concrete floors

    Energy Technology Data Exchange (ETDEWEB)

    Lopez-Mesa, Belinda; Pitarch, Angel; Tomas, Ana; Gallego, Teresa [Department of Mechanical Engineering and Construction (ESTCE), Universitat Jaume I, Av. Sos Baynat s/n, Castellon 12071 (Spain)

    2009-04-15

    In this paper, the environmental impacts of two types of slab systems are studied. The first type, a concrete-based one-way spanning slab, is the most common solution in residential buildings in Spain. The second type, a hollow core slab floor, is increasingly becoming more used in buildings, but is not being broadly used in residential buildings as yet. The study is undertaken through the Life Cycle Analysis methodology, applying the EPS 2000 method. The assessment shows that the environmental impact of a building structure with precast concrete floors is 12.2% lower than that with in situ cast floors for the defined functional unit. (author)

  11. Microstructure and property of zinc phosphate coating on die-casting magnesium alloy AZ91D

    Institute of Scientific and Technical Information of China (English)

    LI Guang-yu; LIAN Jian-she; NIU Li-yuan; JIANG Zhong-hao

    2006-01-01

    A surface treatment method was described, which can form a uniform and dense phosphate conversion coating on the die -casting magnesium alloy AZ91D in a non-chromate and non-nitrite bath. The coating consists of Zn3(PO4)2-4H2O, Zn, AlPO4 and MgZn2(PO4)2 analyzed by XRD. The SEM results show that the microstructure of the zinc phosphate coating transfers from flower-like to slab-like crystals with the increase of immersion time of magnesium alloy samples in the phosphating bath. The zinc phosphate coating formed in the bath with immersion time of 1 min is denser because metallic Zn and insoluble phosphate crystals co-deposit on the magnesium alloy surface and the growth of the crystals are restricted by each others. The zinc phosphate coating on the magnesium alloy is used as the base layer for further cataphoric and powder paintings. The cataphoric painting on AZ91D alloy based on phosphate coating has similar adhesion and corrosion-resistance to that based on the chromate conversion coating. But for powder painting, the former exhibits better adhesion property than the latter, due to the uneven microstructure and the enough thickness of the phosphate coating.

  12. Microstructure and Mechanical Properties of Mg-Al-Ca-Nd Alloys Fabricated by Gravity Casting

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The aims of this study are to investigate the effects of Nd addition in the Mg-Al-Ca alloys on microstructure and mechanical properties. Microstructure of as-cast Mg-5Al-3Ca alloy containing Nd consists of α-Mg matrix,eutectic phase and Al-Nd rich intermetallic compound. As Nd addition was increased, α-Mg matrix morphology was changed from dendritic to equiaxed grains and average value of grain size was decreased. Nd addition to Mg-5Al-3Ca based alloys resulted in the formation of Al-Nd rich intermetallic compounds at grain boundary and α-Mg matrix grains. And these Al-Nd rich intermetallic compounds were dispersed homogeneously. In these alloys, two kinds of eutectic phases were observed, i.e. coarse irregular-shape structure at grain boundary and fine needle-shape structure in the α-Mg matrix grain. It is found that the ultimate strength showed the maximum value of 271 MPa at Mg-5Al-3Ca-2Nd alloy and elongation was decreased as the addition of Nd was increased.

  13. The Kinetics and Dry-Sliding Wear Properties of Boronized Gray Cast Iron

    Directory of Open Access Journals (Sweden)

    Dong Mu

    2013-01-01

    Full Text Available Some properties of boride formed on gray cast iron (GCI have been investigated. GCI was boronized by powder-pack method using Commercial LSB-II powders at 1123, 1173, and 1223 K for 2, 4, 6, and 8 h, respectively. Scanning electron microscopy showed that boride formed on the surface of boronized GCI had tooth-shaped morphology. The hardness of boride formed on surfaces of GCI ranged from 1619 to 1343 HV0.025, and quenched and tempered GCI ranged from 400 to 610 HV0.025. The boride formed in the coating layer confirmed by X-ray diffraction analysis was Fe2B single phase. Depending on boronizing time and temperature, the thickness of coating layers on boronized GCI ranged from 26 to 105 μm. The activation energy was 209 kJ/mol for boronized GCI. Moreover, the possibility of predicting the iso-thickness of boride layers variation was studied. Dry-sliding wear tests showed that the wear resistance of boronized sample was greater than that of quenched and tempered sample.

  14. Effect of austempering parameters on microstructure and mechanical properties of horizontal continuous casting ductile iron dense bars

    OpenAIRE

    Chun-jie Xu; Pan Dai; Zheng-yang Zhang

    2015-01-01

    In the present research, the orthogonal experiment was carried out to investigate the influence of different austempering process parameters (i.e. austenitizing temperature and time, and austempering temperature and time) on microstructure and mechanical properties of LZQT500-7 ductile iron dense bars with 172 mm in diameter which were produced by horizontal continuous casting (HCC). The results show that the major factors influencing the hardness of austempered ductile iron (ADI) are austeni...

  15. Examination of Cast Iron Material Properties by Means of the Nanoindentation Method

    Directory of Open Access Journals (Sweden)

    A. Trytek

    2012-12-01

    Full Text Available The paper presents results of examination of material parameters of cast iron with structure obtained under rapid resolidification conditions carried out by means of the nanoindentation method.

  16. Properties of Cast Films Made from Different Ratios of Whey Protein Isolate, Hydrolysed Whey Protein Isolate and Glycerol

    Directory of Open Access Journals (Sweden)

    Markus Schmid

    2013-08-01

    Full Text Available Whey protein isolate (WPI-based cast films are very brittle, due to several chain interactions caused by a large amount of different functional groups. In order to overcome film brittleness, plasticizers, like glycerol, are commonly used. As a result of adding plasticizers, the free volume between the polymer chains increases, leading to higher permeability values. The objective of this study was to investigate the effect of partially substituting glycerol by hydrolysed whey protein isolate (h-WPI in WPI-based cast films on their mechanical, optical and barrier properties. As recently published by the author, it is proven that increasing the h-WPI content in WPI-based films at constant glycerol concentrations significantly increases film flexibility, while maintaining the barrier properties. The present study considered these facts in order to increase the barrier performance, while maintaining film flexibility. Therefore glycerol was partially replaced by h-WPI in WPI-based cast films. The results clearly indicate that partially replacing glycerol by h-WPI reduces the oxygen permeability and the water vapor transmission rate, while the mechanical properties did not change significantly. Thus, film flexibility was maintained, even though the plasticizer concentration was decreased.

  17. Structure and properties of Fe-Cr-Mo-C bulk metallic glasses obtained by die casting method

    Directory of Open Access Journals (Sweden)

    W. Pilarczyk

    2010-09-01

    Full Text Available urpose: The goal of this work is to investigate structure and properties of Fe54Cr16Mo12C18 alloy rods with different diameters obtained by the pressure die casting method.Design/methodology/approach: Master alloy ingot with compositions of Fe54Cr16Mo12C18 was prepared by induction melting of pure Fe, Cr, Mo, C elements in argon atmosphere. The investigated material were cast in form of rods with different diameters. Glassy and crystalline structures were examined by X-ray diffraction. The microscopic observation of the fracture morphology was carried out by the SEM with different magnification. The thermal properties of the studied alloy were examined by DTA and DSC method.Findings: These materials exhibit high glass-forming ability, excellent mechanical properties and corrosion resistance.Research limitations/implications: It is difficult to obtain a metallic glass of Fe54Cr16Mo12C18 alloy. The investigations carried out on the different samples of Fe54Cr16Mo12C18 bulk metallic alloy allowed to state that the studied ribbon was amorphous whereas rods were amorphous – crystalline.Originality/value: The formation and investigation of the casted Fe-Cr-Mo-C bulk materials and the study of glass-forming ability of this alloy.

  18. Phase-inversion tape casting and oxygen permeation properties of supported ceramic membranes

    NARCIS (Netherlands)

    He, Wei; Huang, Hua; Gao, Jianfeng; Winnubst, A.J.A.; Chen, Chusheng

    2014-01-01

    A variant of tape casting, involving phase inversion, was explored for the preparation of supported ceramic oxygen separation membranes in one step. A slurry of Zr0.84Y0.16O1.92 (YSZ) andLa0.8Sr0.2MnO3 δ (LSM) powders in a N-methyl-2-pyrrolidone solution of polyethersulfone was tape cast, and immers

  19. Developmental epigenetic programming of caste-specific differences in social insects: an impact on longevity.

    Science.gov (United States)

    Vaiserman, Alexander

    2014-01-01

    Social insects are an excellent model system for a deeper understanding of the mechanisms of longevity determination because they have a caste system in which the same genome, due to the differential gene expression, can produce both a short-lived worker and a long-lived queen. For example, in the honeybee, Apis mellifera, queens develop from fertilized eggs that are genetically not different from the eggs that develop into workers. They have, however, a much larger size and specialized anatomy, develop substantially faster and live much longer than worker bees. In many social insects including bees, ants, wasps, and termites, queens and workers show up to a 100-fold difference in lifespan, with reproductive queens having longer longevity than non-reproductive workers. Caste differentiation in social insect species is known to be dependent on the larval nutritional environment. In the honeybee, the caste switching is determined by distinguished feeding of larvae. There is accumulating evidence that queen phenotype is driven by epigenetic mechanisms of gene regulation. Dietary differences during the larval development have been found to lead to differential DNA methylation. This results in caste-biased patterns of gene expression, which, in turn, leads to caste-biased phenotypes, such as short-lived workers and long-lived queens. The investigation of physiological, biochemical and molecular aspects of the biology of queens and workers seems to be a promising way to identifying pathways that control longevity and to developing the treatments designed to influence these pathways.

  20. Development of low-temperature high-strength integral steel castings for offshore construction by casting process engineering

    Directory of Open Access Journals (Sweden)

    Lim Sang-Sub

    2014-12-01

    Full Text Available In casting steels for offshore construction, manufacturing integral casted structures to prevent fatigue cracks in the stress raisers is superior to using welded structures. Here, mold design and casting analysis were conducted for integral casting steel. The laminar flow of molten metal was analyzed and distributions of hot spots and porosities were studied. A prototype was subsequently produced, and air vents were designed to improve the surface defects caused by the release of gas. A radiographic test revealed no internal defects inside the casted steel. Evaluating the chemical and mechanical properties of specimens sampled from the product revealed that target values were quantitatively satisfied. To assess weldability in consideration of repair welding, the product was machined with grooves and welded, after which the mechanical properties of hardness as well as tensile, impact, and bending strengths were evaluated. No substantive differences were found in the mechanical properties before and after welding.

  1. Development of low-temperature high-strength integral steel castings for offshore construction by casting process engineering

    Science.gov (United States)

    Lim, Sang-Sub; Mun, Jae-Chul; Kim, Tae-Won; Kang, Chung-Gil

    2014-12-01

    In casting steels for offshore construction, manufacturing integral casted structures to prevent fatigue cracks in the stress raisers is superior to using welded structures. Here, mold design and casting analysis were conducted for integral casting steel. The laminar flow of molten metal was analyzed and distributions of hot spots and porosities were studied. A prototype was subsequently produced, and air vents were designed to improve the surface defects caused by the release of gas. A radiographic test revealed no internal defects inside the casted steel. Evaluating the chemical and mechanical properties of specimens sampled from the product revealed that target values were quantitatively satisfied. To assess weldability in consideration of repair welding, the product was machined with grooves and welded, after which the mechanical properties of hardness as well as tensile, impact, and bending strengths were evaluated. No substantive differences were found in the mechanical properties before and after welding.

  2. HLA-B27 allele diversity in Indians: impact of ethnic origin and the caste system.

    Science.gov (United States)

    Shankarkumar, U

    2003-01-01

    HLA-B27 is a serological specificity which encompasses an increasing number of subtypes that show varied racial/ethnic prevalence in the world. Here, data from 5129 Indians (4500 population and caste; 629 tribal) is compiled from the literature. In addition, HLA-B27 subtyping of 58 positive individuals from Maharastra is presented. Analysis revealed an increased B27 antigen frequency among the north Indian groups (>5%) compared to the south Indian groups (caste and tribal groups studied. The study showed that more extensive subtyping in other Indian caste groups will be necessary to resolve the evolutionary implications of HLA-B27 subtypes and their relationship to disease association in the Indian context.

  3. Influence of tungsten and titanium on the structure of chromium cast iron

    Directory of Open Access Journals (Sweden)

    D. Kopyciński

    2012-01-01

    Full Text Available The paper analyses the as-cast state structure of chromium cast iron designed for operation under harsh impact-abrasive conditions. In the process of chromium iron castings manufacture, very strong influence on the structure of this material have the parameters of the technological process. Among others, adding to the Fe-Cr-C alloy the alloying elements like tungsten and titanium leads to the formation of additional carbides in the structure of this cast iron, which may favourably affect the casting properties, including the resistance to abrasive wear.

  4. Tensile properties of strip casting 6.5 wt% Si steel at elevated temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Li, Hao-Ze, E-mail: lhzqq83@163.com; Liu, Zhen-Yu, E-mail: zyliu@mail.neu.edu.cn

    2015-07-15

    Tensile behaviors of strip casting 6.5 wt% Si steel are tested at elevated temperatures ranging from 300 °C to 800 °C. A detailed study of the morphology of the fracture surface and the ordered phase at each deforming temperature is carried out by a scanning electron microscope and a transmission electron microscope. The results show that the deforming temperature rather than the ordered degree determines the tensile properties. As the deforming temperature increases, the stress level in the whole deforming stage continually decreases, whereas the elongation gradually increases. The ductile–brittle transition occurs around 350 °C. The elongation of 2% at 300 °C rapidly increases up to 16.4% at 350 °C and the corresponding fracture mode transforms from the complete cleavage fracture to the mixture of the very limited cleavage fracture, intergranular dimple fracture and the dimple fracture. Serrated flow is observed at 350 °C and 400 °C probably due to the occurrence of dynamic strain aging. Due to the gradually weakened grain boundary cohesion with the deforming temperature increasing, intergranular dimple pattern dominates the fracture surface at 600 °C and the elongation slowly increases from 16.4% at 350 °C to 22.8% at 600 °C. At 700 °C and 800 °C, the much more enhanced dynamic recovery, the substantially decreased stress levels which contribute to the inhibition of the intergranular dimple fracture, the much lower content of the B2 ordered phase at 700 °C, and the completely disordered state at 800 °C give rise to the dramatically improved elongations of 88.8% and 130.8%, respectively.

  5. Physicochemical properties and bioactivity of freeze-cast chitosan nanocomposite scaffolds reinforced with bioactive glass

    Energy Technology Data Exchange (ETDEWEB)

    Pourhaghgouy, Masoud, E-mail: m.pourhaghgouy@merc.ac.ir [Department of Nanotechnology & Advanced Materials, Materials & Energy Research Center, Karaj, P.O. Box: 13145-1659 (Iran, Islamic Republic of); Zamanian, Ali, E-mail: a-zamanian@merc.ac.ir [Department of Nanotechnology & Advanced Materials, Materials & Energy Research Center, Karaj, P.O. Box: 13145-1659 (Iran, Islamic Republic of); Shahrezaee, Mostafa, E-mail: moshahrezaee@yahoo.com [Department of Orthopedic Surgery, AJA University of Medical Sciences, Tehran (Iran, Islamic Republic of); Masouleh, Milad Pourbaghi, E-mail: miladpourbaghi@gmail.com [Department of Nanotechnology & Advanced Materials, Materials & Energy Research Center, Karaj, P.O. Box: 13145-1659 (Iran, Islamic Republic of)

    2016-01-01

    Chitosan based nanocomposite scaffolds were prepared by freeze casting method through blending constant chitosan concentration with different portions of synthesized bioactive glass nanoparticles (BGNPs). Transmission Electron Microscopy (TEM) image showed that the particles size of bioactive glass (64SiO{sub 2}.28CaO.8P{sub 2}O{sub 5}) prepared by sol–gel method was approximately less than 20 nm. Fourier Transform Infrared Spectroscopy (FT-IR) and X-ray Diffraction (XRD) analysis showed proper interfacial bonding between BGNPs and chitosan polymers. Scanning Electron Microscopy (SEM) images depicted a unidirectional structure with homogenous distribution of BGNPs among chitosan matrix associated with the absence of pure chitosan scaffold's wall pores after addition of only 10 wt.% BGNPs. As the BGNP content increased from 0 to 50 wt.%, the compressive strength and compressive module values increased from 0.034 to 0.419 MPa and 0.41 to 10.77 MPa, respectively. Biodegradation study showed that increase in BGNP content leads to growth of weight loss amount. The in vitro biomineralization studies confirmed the bioactive nature of all nanocomposites. Amount of 30 wt.% BGNPs represented the best concentration for absorption capacity and bioactivity behaviors. - Highlights: • Particle size of synthesized bioactive glass was approximately less than 20 nm. • Increase in BGNP content did not change the pore channels size. • Addition of 10 wt.% of BGNP led to absence of the pores located on chitosan walls. • Mechanical properties of chitosan scaffold significantly improved by addition of BGNPs. • Chi-BGNPs30 scaffold indicated acceptable absorption capacity and bioactivity behavior.

  6. Microstructure and properties of cast iron by semi-solid die casting process; Hangyoko diecast shita chutetsu no soshiki to seishitsu

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, C.; Kitamura, K.; Ando, Y.; Hironaka, K.

    1996-02-25

    In the semi-solid die casting process, products are made by processing metals in the liquid and solid coexistence region. Die casting experiments were conducted using flaky graphite cast iron by means of the rheocasting method in which semi-solid slurry is directly die cast and the thixocasting method in which raw material billet is heated up to the semi-solid temperature and then die cast. In both the methods, flat plates were produced. In the rheocasting with the solid ratio of 0.2, flat plates of 6 mm thick were obtained. The surface temperature of die was lower than that in the case of melt die casting, which reduced the heat load of die. The macro segregation was also reduced. In the thixocasting, flat plates of 3 mm thick were obtained. Using general flaky graphite cast iron, the microstructure was observed where solid phase austenite is uniformly dispersed in the solid-liquid coexistence region. Austenite and austenite/cementite eutectic was observed in the specimens without treatment after casting. Cementite easily changed into fine graphite spheres through the heat treatment, which has excellent tensile strength of 400 MPa and elongation of 3%. 7 refs., 12 figs., 5 tabs.

  7. Effect of Ni Contents on the Microstructure and Mechanical Properties of Martensitic Stainless Steel Guide Roll by Centrifugal Casting

    Institute of Scientific and Technical Information of China (English)

    Villando Thursdiyanto; Eun-Jae Bae; Eung-Ryul Baek

    2008-01-01

    A novel process based on centrifugal casting was developed to produce martensitic stainless steel for guideroll materials. Centrifugal casting provides a lower production cost and less of the thermal cracking defects which normally occur in the overlaid welding process. In this study, the effects of Ni on the microstructure and mechanical properties of martensitic stainless steel were investigated. The results show that the addition of Ni resulted in a decrease in the volume fraction of delta ferrite and an increase in the volume fraction of the retained austenite, respectively. Moreover, a tensile strength of 1600 MPa with an elongation of 4% were obtained after tempering at 500℃ for 2 h. These values were higher than those obtained by using the conventional overlaid process.

  8. Influence of stress relief annealing on the microstructure and properties of GX12CrMoVNbN9-1(GP91 cast steel

    Directory of Open Access Journals (Sweden)

    G. Golański

    2011-04-01

    Full Text Available The paper presents an effect of stress relief annealing, applied to casts after the repair by welding, on the microstructure and mechanical properties of quenched and tempered martensitic GX12CrMoVNbN9 – 1 cast steel (called GP91. The test pieces being the subject of research were taken out from a test coupon. Heat treatment of GP91 cast steel was carried out at the parameters of temperature and time appropriate for the treatment of multi-ton steel casts, while stress relief annealing was performed at the temperatures of 730 and 750oC.After quenching and tempering GP91 cast steel was characterized by the microstructure of high-tempered martensite with numerousprecipitations of carbides of diverse size. Mechanical properties of the investigated cast steel after heat treatment fulfilled the standard requirements. Stress relief annealing contributes to the processes of recovery and recrystallization of the matrix as well as the privileged precipitation of M23C6 carbides on grain boundaries. Changes in the microstructure of the examined cast steel cause deterioration in mechanical properties – the higher the temperature of stress relief annealing, the greater the deterioration.

  9. EFFECT OF LOW-FREQUENCY ELECTROMAGNETIC FIELD ON THE AS-CASTING MICROSTRUCTURES AND MECHANICAL PROPERTIES OF HDC 2024 ALUMINUM ALLOY

    Institute of Scientific and Technical Information of China (English)

    Q.F.Zhu; Z.H.Zhao; J.Z.Cui; Y.B.Zuo; F.Qu

    2008-01-01

    The influences of the low frequency electromagnetic field on the horizontal direct chill casting process were investigated experimentally. Ingots of 2024 aluminum alloy with a cross size of 40 mm×200 mm were produced by the conventional horizontal chill casting process and low frequency electromagnetic horizontal chill casting processrespectively. The as-cast structures and the mechanical property of the ingots were examined. The results showed that the low frequency electromagnetic field could substantially refine the microstructures and pronouncedly reduce the macrosegregation in the horizontal direct chill casting process. Moreover, the surface quality of the ingot was prominently improved by the low frequency electromagnetic field. The fracture strength and elongation percentage of the ingot was increased with the low frequency electromagnetic field.

  10. Influence of New Sol-gel Refractory Coating on the Casting Properties of Cold Box and Furan Cores for Grey Cast iron

    DEFF Research Database (Denmark)

    Nwaogu, Ugochukwu Chibuzoh; Poulsen, T.; Bischoff, C

    2010-01-01

    New Sol-Gel coated sand cores made from coldbox and furan binder systems were investigated. The idea of the coating was to improve the surface quality of castings. Grey iron was cast on the cores in a sand casting process. The effect of the high temperature of the melt on the cores was assessed...... transport zone (VTZ) when in contact with the melt is larger than it is in a coldbox which means the furan cores have higher moisture content. The new sol-gel coating has the potential for improving the surface quality of castings without negative effects on the graphite distribution. The surface...... of castings made using the new sol-gel coated furan cores show better surface quality than those made using the coldbox....

  11. Structure and Properties of Cast Near-Congruent Copper-Manganese Alloys

    Science.gov (United States)

    Chaput, Kevin; Trumble, Kevin P.

    2014-10-01

    Microstructure development in the casting of copper-manganese alloys based on the congruent point at 34.6 wt pct Mn and 1146 K (873 °C) has been studied. The alloys were prepared by induction melting of electrolytic Cu and Mn in clay-graphite crucibles in open air. Under conventional casting conditions, the alloys exhibit fine cellular (non-dendritic) solidification morphology with a distinct absence of solidification shrinkage microporosity, and they maintain these attributes over a composition range of approximately 3 wt pct Mn about the congruent point. The high Mn concentration in the alloy admits carbon into solution in the melt, resulting in formation of manganese carbide Mn7C3 particles having two different forms (globular and angular) in the cast microstructure. The Mn carbide was eliminated or controlled to low levels by melting in an alumina or a silicon carbide crucible, or in a clay-graphite crucible at lower temperatures. Microstructure development in casting the alloy was analyzed in terms of the available phase diagrams and thermochemical data. Hardness and tensile testing indicated a potent solid solution strengthening effect of Mn and high ductility in the as-cast condition, with additional hardness (strength) when the alloy contains the Mn carbide phase.

  12. Impact of arbitrary and mean transfer of dental casts to the articulator on centric occlusal errors.

    Science.gov (United States)

    Morneburg, Thomas R; Pröschel, Peter A

    2011-06-01

    When fabricating dental restorations, casts are usually transferred to the articulator based on arbitrary hinge axes or mean values instead of true hinge axis points. Using arbitrary hinge axis points or mean values can lead to occlusal errors if the vertical relation is changed in the articulator (e.g., when a centric record is used). This study predicted the probability of occlusal errors occurring in a group of subjects when casts are mounted based on arbitrary hinge axis points or mean values. In 57 healthy volunteers, true hinge axis points, arbitrary hinge axis points, right infraorbital point, maxillary incisal point, and the palatal cusps of the second molars were determined. Mean hinge axis points were established based on Balkwill angles between 17° and 25°. Occlusal errors evoked by cast mounting in relation to arbitrary or mean axes compared to true hinge axes were calculated. Errors were determined for vertical relation settings of 2 and 4 mm. With 2 mm vertical relation, occlusal errors ≥340 µm occurred with a 10% probability with arbitrary hinge axis mounting. At the same probability level, the error increased moderately to ≥440 µm with mean value mounting and a Balkwill angle of 17°. With a Balkwill angle of 25° occlusal errors ≥1,120 µm occurred with 10% probability. Occlusal errors increased considerably with a vertical relation setting of 4 mm. If vertical relation shall be altered, a transfer of the casts according to arbitrary hinge axes is recommended. If casts are transferred according to mean values, errors are bigger depending on the articulator used.

  13. Effects of different cooling rates during two casting processes on the microstructures and mechanical properties of extruded Mg-Al-Ca-Mn alloy

    Energy Technology Data Exchange (ETDEWEB)

    Xu, S.W., E-mail: xushiwei@stn.nagaokaut.ac.jp [Department of Mechanical Engineering, Nagaoka University of Technology, Nagaoka 940-2188 (Japan); Oh-ishi, K.; Kamado, S.; Takahashi, H.; Homma, T. [Department of Mechanical Engineering, Nagaoka University of Technology, Nagaoka 940-2188 (Japan)

    2012-04-30

    Highlights: Black-Right-Pointing-Pointer Ordered monolayer GP zone was formed by increasing cooling rate. Black-Right-Pointing-Pointer Finer extruded microstructure was obtained by increasing cooling rate. Black-Right-Pointing-Pointer Higher number density precipitates was obtained by increasing cooling rate. Black-Right-Pointing-Pointer Tensile 0.2% proof stress was increased by 105 MPa by increasing cooling rate. Black-Right-Pointing-Pointer Extruded DC-cast alloy shows higher tensile 0.2% proof stress of 409 MPa. - Abstract: In this study, Mg-3.6Al-3.4Ca-0.3Mn (wt.%) (which is denoted AXM4303) alloy ingots were prepared by two casting processes with different cooling rates: permanent mold (PM) casting, which has a lower cooling rate of 10-20 Degree-Sign C/s and direct chill (DC) casting, which has a higher cooling rate of 100-110 Degree-Sign C/s. Then, these two types of AXM4303 alloy ingots were hot extruded at 400 Degree-Sign C under the same conditions. The microstructures of the as-cast and extruded alloy samples were systematically investigated by field-emission scanning electron microscope (FE-SEM), transmission electron microscope (TEM) and electron backscattered diffraction (EBSD) systems. The effects of the different cooling rates during the casting process on the microstructures and mechanical properties of the extruded AXM4303 alloy samples were evaluated. The results show that the strength of the extruded Mg-Al-Ca-Mn alloy can be substantially increased by microstructural control during the casting process. Because the cooling rate of the DC casting process is much faster than the cooling rate of PM casting, the DC-cast AXM4303 has the following properties: (i) the lamellar eutectic structure and dendrite cell size are significantly refined, (ii) the ordered monolayer GP zones enriched with Al and Ca nucleate with no growth, and (iii) most of the Mn remains in solution in the matrix. Thus, after hot extrusion, the DC-cast AXM4303 has finer

  14. The Effect of Casting Solvent on the Electrical Property of Polyaniline/Polyacrylonitrile

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Blends of dodecylbenzene sulfonic acid doped polyaniline (PANI-DBSA) and polyacrylonitrile (PAN) dissolved in either CHCl3/DMF or CHCl3/DMSO mixture were solution cast. The conductivity of the blends with various compositions was measured and the doped cxtent of PANIDBSA in different casting solvent systems was studied.Solution blends prepared from CHCl3/DMSO displayed higher conductivity than those obtained via CHCl3/DMF.The dedoping reaction of PANI-DBSA in CHCl3/DMF identified by UV-Vis and FTIR analysis contributed to the lower conductivity of PANI-DBSA/PAN blend.

  15. A Comparative Study on Wear Properties of As Cast, Cast Aged and Forge Aged A356 Alloy with Addition of Grain Refiner and/or Modifier

    Directory of Open Access Journals (Sweden)

    D.G. Mallapur

    2015-03-01

    Full Text Available In the present work, a comparative wear behavior study of three categories of materials viz, as cast, cast aged (casting followed by T6 and forge aged (forging followed by T6 has been investigated. Neither melt treatment nor solid state processing (like aging and forging seems to be altering the wear behavior of the materials drastically. Cast aged A356 materials exhibit higher wear resistance compared to as cast and forge aged A356 materials. Further, it was observed that cast aged samples register lower coefficient of friction compared to other samples. It is also noted that the difference in wear behavior is revealed only at conditions of higher load, higher speed and longer sliding distance of testing. At lower regimes the difference is marginal. Among cast aged samples, ones treated with combined addition exhibit better wear resistance compared to other materials. Samples treated with combined addition register lowest coefficient of friction followed by samples treated with Sr, those with B, those with Ti and untreated ones. Abrasive wear mechanism is found to be operative in the regime of higher loading and higher velocity of sliding. Adhesive wear mechanism seems to be dominating the wear process at the lower regime of load and velocity of sliding.

  16. Microstructure and Mechanical Properties of MWCNTs Reinforced A356 Aluminum Alloys Cast Nanocomposites Fabricated by Using a Combination of Rheocasting and Squeeze Casting Techniques

    Directory of Open Access Journals (Sweden)

    Abou Bakr Elshalakany

    2014-01-01

    Full Text Available A356 hypoeutectic aluminum-silicon alloys matrix composites reinforced by different contents of multiwalled carbon nanotubes (MWCNTs were fabricated using a combination of rheocasting and squeeze casting techniques. A novel approach by adding MWCNTs into A356 aluminum alloy matrix with CNTs has been performed. This method is significant in debundling and preventing flotation of the CNTs within the molten alloy. The microstructures of nanocomposites and the interface between the aluminum alloy matrix and the MWCNTs were examined by using an optical microscopy (OM and scanning electron microscopy (SEM equipped with an energy dispersive X-ray analysis (EDX. This method remarkably facilitated a uniform dispersion of nanotubes within A356 aluminum alloy matrix as well as a refinement of grain size. In addition, the effects of weight fraction (0.5, 1.0, 1.5, 2.0, and 2.5 wt% of the CNT-blended matrix on mechanical properties were evaluated. The results have indicated that a significant improvement in ultimate tensile strength and elongation percentage of nanocomposite occurred at the optimal amount of 1.5 wt% MWCNTs which represents an increase in their values by a ratio of about 50% and 280%, respectively, compared to their corresponding values of monolithic alloy. Hardness of the samples was also significantly increased by the addition of CNTs.

  17. Effect of Melt Cleanliness on the Mechanical Properties and Microstructure on AZ91E Mg Alloy Castings

    Science.gov (United States)

    Elsayed, A.; Ravindran, C.

    2013-10-01

    The current study examines various filter configurations, argon bubbling, and degasser addition to improve melt cleanliness of AZ91E permanent mold castings. The unfiltered castings had an average yield strength, ultimate tensile strength, and elongation of 93.3, 153.3 MPa, and 2.2% respectively. Using a fine mesh filter within the well of the mold, the ultimate tensile strength and elongation increased by 9 and 41%, respectively, compared to the unfiltered samples. A combination of a fine filter and argon bubbling resulted in an average increase in ultimate tensile strength and elongation of 29 and 123%, respectively, that matched the performance of the C2Cl6-based degassed castings with 95.8, 194.3, and 4.9% for yield strength, ultimate tensile strength, and elongation, respectively. The addition of the C2Cl6-based degasser released harmful vapors that can be avoided using the fine filter with argon bubbling. In all cases, the removal of MgO-based inclusions improved mechanical properties.

  18. Effects of heat treatment on mechanical properties and microstructure of tungsten fi ber reinforced grey cast iron matrix composites

    Directory of Open Access Journals (Sweden)

    Peng jianHong

    2009-11-01

    Full Text Available In this study, grey cast iron matrix composites reinforced by different volume fractions of tungsten fibers (Vr = 0.95 %, 1.90 %, 2.85 %, 3.80 % were investigated in as-cast and under the heat treatment temperatures of 1,000℃ and 1,100℃. The microstructure and mechanical properties of the composites were analyzed and tested by means of SEM, micro-hardness tester and three-point bend testing. The results show that with increasing of the volume fraction of tungsten fibers, the composites reinforced by the tungsten fiber have higher fl exural strength and modulus than that of cast iron without reinforcement, and the fl exural strength increases with the increasing of heat treatment temperatures. Due to diffusion reaction between matrix and reinforcing phases, the process of heat treatment, the number of graphite fl akes in the matrix seemingly becomes lower; and some hard carbide particles are formed around the residual tungsten fi bers. Not only does the hardness of both matrix and reinforcement change tremendously, but also the region of reinforcement is also extended from the original 0.11 mm to 0.19 mm in radius.

  19. Effect of C content on the mechanical properties of solution treated as-cast ASTM F-75 alloys.

    Science.gov (United States)

    Herrera, M; Espinoza, A; Méndez, J; Castro, M; López, J; Rendón, J

    2005-07-01

    The mechanical properties of solution treated ASTM F-75 alloys with various carbon contents have been studied. Alloys cast under the same conditions were subjected to solution treatment for several periods and then their tensile properties were evaluated. In the as-cast conditions, the alloys exhibited higher strength values with increasing carbon content whereas their ductility was not significantly affected. For the solution treated alloys, the variation of the strength was characterized by a progressive increase for short treatment times until a maximum value was achieved, which was followed by a diminution in this property for longer treatment times. This behavior was more accentuated for the case of the alloys with medium carbon contents, which also exhibited the highest values of strength. Furthermore, the alloy's ductility was enhanced progressively with increasing solution treatment time. This improvement in ductility was significantly higher for the medium carbon alloys compared with the rest of the studied alloys. Thus, high and low carbon contents in solution treated ASTM F-75 alloys did not produced sufficiently high tensile properties.

  20. Influence of gelling additives in the green properties of Al{sub 2}O{sub 3} bodies obtained by aqueous gel casting

    Energy Technology Data Exchange (ETDEWEB)

    Millan, A.J. [IUT, Caracas (Venezuela). Dept. Materiales; Baudin, C.; Moreno, R.; Nieto, M.I. [Consejo Nacional de Investigaciones Cientificas, Madrid (Spain). Ist. de Ceramica y Vidrio

    2002-07-01

    The use of gelling additives, as polysaccharides, in colloidal processing provides adequate mechanical properties to the green bodies to be handled. In this work, Al{sub 2}O{sub 3} gel casting is studied by using agar, agarose and carrageenan as gelling additives. The rheological behaviour of the gel casting slurries on cooling is studied. The green characteristics of the gel cast bodies prepared at different conditions are characterised in terms of density, microstructure and mechanical behaviour (bend strength, elastic modulus) at room temperature. A correlation between the obtained results is established and the best compositions and processing conditions are discussed. (orig.)

  1. Properties of cast films made of chayote (Sechium edule Sw.) tuber starch reinforced with cellulose nanocrystals

    Science.gov (United States)

    In this study, cellulose (C) and cellulose nanocrystals (CN) were blended with chayote tuber (Sechium edule Sw.) starch (CS) in formulations cast into films. The films were conditioned at different storage temperatures and relative humidity (RH), and analyzed by mechanical tests, X-ray diffraction, ...

  2. A Study the relationship between composition, structure and properties of ductile iron in continuous casting

    OpenAIRE

    2011-01-01

    The developed empirical relationships have practical significance and used for determine the structural composition of iron on known data of express-analysis and for optimization technical process of obtaining castings of ductile iron at Public corporation «Gomel foundry «TSENTROLIT».

  3. Thermo-mechanical properties and cracking during solidification of thin slab cast steel

    NARCIS (Netherlands)

    Santillana, M.B.

    2013-01-01

    Nowadays a vast majority of the steel produced worldwide is via the continuous casting process route because this is the most low-cost, efficient and high quality method to mass produce metal products in a variety of sizes and shapes. Most of the continuous casters are the initial manufacturing step

  4. Study on Properties of Cast Iron Materials for Machine Tool%机床用铸铁材料的性能研究

    Institute of Scientific and Technical Information of China (English)

    符特

    2013-01-01

    综述了机床用铸铁(灰铸铁、球墨铸铁和蠕墨铸铁)材料的性能.分析了化学成分,力学佳能,应用领域和失效方式,并且介绍了提高其耐磨性的机理研究和工艺方法等方面取得的进展.这能为机床选材和制造提供依据.%The properties of cast iron, such as gray cast iron, vermicular cast iron and spheroidal graphite cast iron for machine tool, were reviewed. The chemical composition, mechanical property, application and failure mode were analyzed. And the recent progress of the mechanism research and process method about improving its wear resistance was introduced. This can provide the basis for choosing materials and manufacturing of machine tool.

  5. The effect of water-soluble polymers on the microstructure and properties of freeze-cast alumina ceramics

    Science.gov (United States)

    Pekor, Christopher Michael

    Porous ceramics can be divided into three separate classes based on their pore size: microporous ceramics with pores less than 2 nm, mesoporous ceramics with pores in the range of 2--50 nm and macroporous ceramics with pores that are greater than 50 nm. In particular, macroporous ceramics are used in a variety of applications such as refractories, molten metal filtration, diesel particulate filters, heterogeneous catalyst supports and biomedical scaffolds. Freeze casting is a novel method used to create macroporous ceramics. In this method growing ice crystals act as a template for the pores and are solidified, often directionally, through a ceramic dispersion and removed from the green body through a freeze drying procedure. This method has attracted some attention over the past few years due to its relative simplicity, flexibility and environmental friendliness. On top of this freeze casting is capable of producing materials with high pore volume fractions, which is an advantage over processing by packing and necking of particles, where the pore volume fraction is typically less than 50%. Many of the basic processing variables that affect the freeze cast microstructure, such as the temperature gradient, interfacial velocity and solid loading of the dispersion have been well established in the literature. On the other hand, areas such as the effect of additives on the microstructure and mechanical properties have not been covered in great detail. In this study the concept of constitutional supercooling from basic solidification theory is used to explain the effects of two water-soluble polymers, polyethylene glycol and polyvinyl alcohol, on the microstructure of freeze cast alumina ceramics. In addition, changes in the observed microstructure will be related to experimentally determined values of permeability and compressive strength.

  6. Structure of Water Mist Stream and its Impact on Cooling Efficiency of Casting Die

    Directory of Open Access Journals (Sweden)

    R. Władysiak

    2012-04-01

    Full Text Available The work is a continuation of research on the use water mist cooling in order to increase efficiency of die-casting aluminum alloys. The paper presents results of research and analysis process, spraying water and generated a stream of water mist, the effect of the type of nozzle, the nozzle size and shape of the emitting of the water mist on the wall surface of casting die on the microstructure and geometry of water mist stream and cooling efficiency. Tests were used to perform high-speed camera to record video in the visible and infrared camera. Results were used to develop a computerized image analysis and statistical analysis. The study showed that there are statistical relationships between water and air flow and geometry of the nozzle and nozzle emitting a stream of microstructure parameters of water mist and heat the incoming stream. These relationships are described mathematical models that allow you to control the generating of adequate stream of water mist and a further consequence, the cooling efficiency of casting die.

  7. Materials for Advanced Ultrasupercritical Steam Turbines Task 4: Cast Superalloy Development

    Energy Technology Data Exchange (ETDEWEB)

    Thangirala, Mani

    2015-09-30

    The Steam Turbine critical stationary structural components are high integrity Large Shell and Valve Casing heavy section Castings, containing high temperature steam under high pressures. Hence to support the development of advanced materials technology for use in an AUSC steam turbine capable of operating with steam conditions of 760°C (1400°F) and 35 Mpa (5000 psia), Casting alloy selection and evaluation of mechanical, metallurgical properties and castability with robust manufacturing methods are mandated. Alloy down select from Phase 1 based on producability criteria and creep rupture properties tested by NETL-Albany and ORNL directed the consortium to investigate cast properties of Haynes 282 and Haynes 263. The goals of Task 4 in Phase 2 are to understand a broader range of mechanical properties, the impact of manufacturing variables on those properties. Scale up the size of heats to production levels to facilitate the understanding of the impact of heat and component weight, on metallurgical and mechanical behavior. GE Power & Water Materials and Processes Engineering for the Phase 2, Task 4.0 Castings work, systematically designed and executed casting material property evaluation, multiple test programs. Starting from 15 lbs. cylinder castings to world’s first 17,000 lbs. poured weight, heavy section large steam turbine partial valve Haynes 282 super alloy casting. This has demonstrated scalability of the material for steam Turbine applications. Activities under Task 4.0, Investigated and characterized various mechanical properties of Cast Haynes 282 and Cast Nimonic 263. The development stages involved were: 1) Small Cast Evaluation: 4 inch diam. Haynes 282 and Nimonic 263 Cylinders. This provided effects of liquidus super heat range and first baseline mechanical data on cast versions of conventional vacuum re-melted and forged Ni based super alloys. 2) Step block castings of 300 lbs. and 600 lbs. Haynes 282 from 2 foundry heats were evaluated which

  8. High integrity automotive castings

    Energy Technology Data Exchange (ETDEWEB)

    Weiss, D. [Eck Industries Inc., St. Manitowoc, WI (United States)

    2007-07-01

    This paper described the High Integrity Magnesium Automotive Casting (HI-MAC) program, which was developed to ensure the widespread adoption of magnesium in structural castings. The program will encourage the use of low pressure permanent molds, squeeze casting, and electromagnetic pumping of magnesium into dies. The HI-MAC program is currently investigating new heat treatment methods, and is in the process of creating improved fluid flow and solidification modelling to produce high volume automotive components. In order to address key technology barriers, the program has been divided into 8 tasks: (1) squeeze casting process development; (2) low pressure casting technology; (3) thermal treatment; (4) microstructure control; (5) computer modelling and properties; (6) controlled molten metal transfer and filling; (7) emerging casting technologies; and (8) technology transfer throughout the automotive value chain. Technical challenges were outlined for each of the tasks. 1 ref., 3 tabs., 5 figs.

  9. Influence of heat treatment on microstructure and tensile properties of a cast Al-Cu-Si-Mn alloy

    Directory of Open Access Journals (Sweden)

    Liu Zhixue

    2013-11-01

    Full Text Available Solution and aging treatments are important approaches to improve mechanical properties and microstructure of aluminum-base alloys. In this research, a new type high strength Al-Cu-Si-Mn cast alloy was prepared. The effect of different solution and aging treatment temperatures on microstructure and mechanical properties of the Al-Cu-Si-Mn cast alloy were studied by means of microstructure observation and mechanical properties testing. Results showed that after solution treated at different temperatures for 12 h and aged at 175 ℃ for 12 h, with the increase of the solution temperature, both the tensile strength and the elongation of the alloy firstly increase and then decrease, and reach their peak values at 530 ℃. When the solution temperature is below 530 ℃, the microstructure of the alloy consists of α phase, undissolved θ phase and T phase; while when it exceeds 530 ℃, the microstructure only consists of α phase and T phase. After solution treated at 530 ℃ for 12 h and aged at different temperatures for 12 h, both the tensile strength and the elongation of the alloy firstly increase and then decrease with the increasing of temperature, and reach their peak values at 175 ℃. Therefore, the optimal heat treatment process for the alloy in this study is 12 h solution at 530 ℃ and 12 h aging at 175 ℃, and the corresponding tensile strength is 417 MPa, elongation is 4.0%.

  10. Effect of Gas Pores on Mechanical Properties of High-Pressure Die-Casting AM50 Magnesium Alloy.

    Science.gov (United States)

    Jiang, Wei; Cao, Zhanyi; Liu, Liping; Jiang, Bo

    2016-08-01

    High-pressure die-casting (HPDC) AM50 tensile specimens were used to investigate characteristics of gas pores and its effect on mechanical properties of HPDC AM50 magnesium alloy. Combining microstructure morphology gained from optical microscopy, scanning electron microscopy (SEM), and three-dimensional (3D) reconstruction with the experimental data from uniaxial tensile testing, we pursued the relationship between gas pores and the mechanical properties of HPDC AM50 Mg alloy. Results indicate that comparing with 3D reconstruction models, 2D images like optical metallography images and SEM images have one-sidedness. Furthermore, the size and maximum areal fraction of gas pores have negative effects on the mechanical properties of HPDC AM50 Mg alloy. With increase of the maximum size of gas pores in the specimen, the ultimate tensile strength (UTS) and elongation decrease. In addition, with the maximum areal fraction becoming larger, both the UTS and elongation decrease linearly.

  11. PHYSICOCHEMICAL AND ANTIBACTERIAL PROPERTIES OF PLA-CHITOSAN BLENDS OBTAINED BY CASTING WITH POTENTIAL USE AS AGRICULTURAL MULCH FILMS

    Directory of Open Access Journals (Sweden)

    Danila Merino

    2016-03-01

    Full Text Available PLA-Chitosan films compatibilized with hexamethylenediisocyanate (HDI were obtained by casting and subsequent hot pressing. The films were prepared with different contents of chitosan (CS and then its physicochemical properties were studied by Fourier Transform infrared spectroscopy (FTIR, thermogravimetric analysis (TGA, differential scanning calorimetry (DSC, optical microscopy (OM and X-ray diffraction (XRD. It was found that the compatibilizing agent reacts completely and that chitosan affects the thermal properties of the films decreasing their decomposition temperatures, glass transition temperature (Tg and melting (Tm and increase its crystallinity. From the functional standpoint, antimicrobial properties of each blend were tested against Pseudomonas syringae pv tomato DC-3000. The increase in chitosan content was proportional to the antimicrobial effect allowing project its potential application in the agronomic field.

  12. Improvement of Structure and Properties of Cast Ferrite-Pearlite Steels for Freight Railway Cars

    Directory of Open Access Journals (Sweden)

    A. Rabinovich

    2008-03-01

    Full Text Available As it i s known For increasing of propcnics (YTS 2 380 MPa of cast stcds i t is c f k ~ i v tco incrcasc conlcnt o f alhsti~uiionaal lloyingclcrncnts, (Si, Mn, Cr, Ni. 1 lowevcr it lcads to rising in pricc olstccl ton. lncrcasing of Si and Mn conrcnl only is limitcd hy decreasing o lductility and weld nhility. As a rule silicon contcnt at ~hcsca ccls is not highcr than 0.4-0.67'0 and Si:Mn ratio is not highcr khan 1:2. Nowfor grain rcfincmcnt ~wc sin oculation of stcct by nitrogcn and clcincnrs with high chcmical affinity to nltmgcn. Mostly vanadium i s usd.howcvcr niobium sornctime is uscd. Dissldvantagcs of this arc high cost of alloying clcmcnrs and low thcrrnodynamic stability OFvanadium and niobium nitridcs. Parlicles of V(C,N and Nh(C.N dissolvc during hcating fnr licnt trcatmcnt or during wclding. It [cads lodccrcasing of grain refinement elfcc!.Adaptat ion or this microalloying stratcgy Tor casts producing For rrcight mil way cars let cstirnatc possibility of application thcsc casts in ancw gcnerazion freight railway cars.

  13. The structure and mechanical properties of pearlitic-ferritic vermicular cast iron

    Directory of Open Access Journals (Sweden)

    E. Guzik

    2012-01-01

    Full Text Available The results of studies on the use of magnesium alloy in modern Tundish + Cored Wire injection method for production of vermicular graphite cast irons were described. The injection of Mg Cored Wire length is a treatment method which can be used to process iron melted in an electric induction furnace. This paper describes the results of using a high-magnesium ferrosilicon alloy in cored wire for the production of vermicular graphite cast irons at the; Tundish + Cored Wire to be injected methods (PE for pearlitic-ferritic matrix GJV with about 25 %ferrite content. The results of calculations and experiments have indicated the length of the Cored Wire to be injected basing on the initial sulfur content and weight of the treated melt. The paper presents a microstructure matrix and vermicular graphite in standard sample and different walled castings. The results of numerous trials have shown that the magnesium Tundish + PE Method process can produce high quality vermicular graphite irons under the specific industrial conditions of the above mentioned foundries.

  14. Improving Microstructure and Mechanical Properties for Large-Diameter 7075 Aluminum Alloy Ingots by a Forced Convection Stirring Casting Process

    Science.gov (United States)

    Qi, Mingfan; Kang, Yonglin; Zhu, Guoming; Li, Yangde; Li, Weirong

    2017-01-01

    A simple process so-called forced convection stirring casting (FCSC) was proposed to prepare large-diameter 7075 Al alloy ingots. The flow behavior, temperature, and composition fields of the melt in the FCSC process were simulated. The macromorphology, macrosegregation, microstructure, and mechanical properties of the ingots prepared by the FCSC were studied and compared with those prepared by normal casting (NC). The results showed that in the FCS device, the strong convection caused by the axial flow and circular flow rapidly promoted the uniformity of the temperature and composition fields of the melt. Microstructures of the FCSC ingots from the edge to the center were all nearly spherical grains, which were much finer and more uniform than that of the NC ingots. The rotation speed played an important role in the microstructure of the FCSC ingots, and the grains became finer and rounder as the speed increasing. The FCSC process effectively eliminated cracks, improved macrosegregation, and decreased the eutectic phase area fraction and the average grain boundary thickness of ingots. Mechanical properties of the ingots prepared by the FCSC are far better than that of the NC ingots.

  15. The relationship between microstructure and magnetic properties of Si-containing permalloy strips fabricated by melt drag casting

    Energy Technology Data Exchange (ETDEWEB)

    Lim, K.M. [Foundry Research Team, Korea Institute of Industrial Technology, Incheon 994-32 (Korea, Republic of); Park, S.Y. [Department of Materials Science and Engineering, Pohang University of Science and Technology, Pohang 790-784 (Korea, Republic of); Namkung, J. [Casting Process Research Team, Research Institute of Industrial Science and Technology, Pohang 790-785 (Korea, Republic of); Kim, M.C. [Casting Process Research Team, Research Institute of Industrial Science and Technology, Pohang 790-785 (Korea, Republic of); Park, C.G. [Department of Materials Science and Engineering, Pohang University of Science and Technology, Pohang 790-784 (Korea, Republic of)]. E-mail: cgpark@postech.ac.kr

    2007-03-25

    The effects of Si addition on microstructure and magnetic properties of permalloy strips fabricated by the melt drag casting method were investigated. Permalloy strips with 200 mm width were successfully fabricated by melt drag casting followed by homogenizing, cold rolling and annealing. In order to understand the relationship between microstructure and magnetic properties, we measured permeability and analyzed microstructure as a function of Si content by optical microscopy, X-ray diffraction and transmission electron microscopy. The effective permeability went through a maximum value in 2 at.% Si added permalloy strips and then decreased with increasing Si content. Increasing Si content enlarged grain size, which resulted in improvement of permeability. Permalloy strips with 5 at.% Si, however, showed drastically reduced permeability than that of 2 at.% Si added ones notwithstanding their coarse grain size and little oxide inclusion. The degradation of permeability in over-added Si above 2 at.% could be explained by formation of Ni{sub 3}Fe ordered phase, which increase magneto-crystalline anisotropy.

  16. Modeling and Analysis of Mechanical Properties of Aluminium Alloy (A413 Processed through Squeeze Casting Route Using Artificial Neural Network Model and Statistical Technique

    Directory of Open Access Journals (Sweden)

    R. Soundararajan

    2015-01-01

    Full Text Available Artificial Neural Network (ANN approach was used for predicting and analyzing the mechanical properties of A413 aluminum alloy produced by squeeze casting route. The experiments are carried out with different controlled input variables such as squeeze pressure, die preheating temperature, and melt temperature as per Full Factorial Design (FFD. The accounted absolute process variables produce a casting with pore-free and ideal fine grain dendritic structure resulting in good mechanical properties such as hardness, ultimate tensile strength, and yield strength. As a primary objective, a feed forward back propagation ANN model has been developed with different architectures for ensuring the definiteness of the values. The developed model along with its predicted data was in good agreement with the experimental data, inferring the valuable performance of the optimal model. From the work it was ascertained that, for castings produced by squeeze casting route, the ANN is an alternative method for predicting the mechanical properties and appropriate results can be estimated rather than measured, thereby reducing the testing time and cost. As a secondary objective, quantitative and statistical analysis was performed in order to evaluate the effect of process parameters on the mechanical properties of the castings.

  17. Introduction on the fabrication technique of phosphor in glass by tape-casting and investigation on the chromaticity property.

    Science.gov (United States)

    Wang, Fangyu; Lin, Yue; Shi, Hongling; Wang, Wenchao; Deng, Zhonghua; Chen, Jian; Yuan, Xuanyi; Cao, Yongge

    2014-08-25

    We introduce a new fabrication technique of phosphor in glass (PiG) for light-emitting diodes (LEDs) employing the tape-casting. Through the detailed process described herein and the measurement results, it is clear that the PiG-on-glass not only share the same characteristic of those obtained from other techniques or the bulk PiG, but with more precisely controlled width from a few to hundreds micrometers. The samples are mounted on blue InGaN LED chips to test the color properties of the white light. Besides, we established an empirical model that could predict the final color properties of LEDs solely by the phosphor concentration of phosphor glass under certain conditions. This model would greatly facilitate the design of PiG-based LEDs.

  18. PZT/P(VDF-HFP) 0-3 composites as solvent-cast thin films: preparation, structure and piezoelectric properties

    Energy Technology Data Exchange (ETDEWEB)

    Wegener, Michael; Arlt, Kristin [Functional Polymer Systems, Fraunhofer Institute for Applied Polymer Research (IAP), Geiselbergstrasse 69, 14476 Potsdam-Golm (Germany)], E-mail: michael.wegener@iap.fraunhofer.de

    2008-08-21

    Composite films of lead zirconate titanate (PZT) and poly(vinylidene fluoride-hexafluoropropylene) (P(VDF-HFP)) were prepared as 100 {mu}m thin films by solvent casting. Within the 0-3 composites, the ceramic-volume fraction was varied between 0.19 and 0.65, which yielded films with different structural and dielectric properties. These influenced the piezoelectric properties of the composite films found after electric poling, which was performed here at room temperature. The piezoelectric activity, with a maximum piezoelectric coefficient of 11 pC N{sup -1} in the film-thickness direction, originates from the polarization of the embedded ceramic particles as proved by poling experiments in corona discharges as well as in direct contact.

  19. Crystallization and mechanical properties of biodegradable poly(p-dioxanone)/octamethyl-polyhedral oligomeric silsesquioxanes nanocomposites via simple solution casting method

    Indian Academy of Sciences (India)

    Zhecun Wang; Chengdong Xiong; Qing Li

    2015-10-01

    In this study, biodegradable poly(p-dioxanone) (PPDO)/octamethyl-polyhedral oligomeric silsesquioxanes (ome-POSS) nanocomposites were fabricated by the simple solution casting method with various ome-POSS loadings. Scanning electron microscopic observations indicate that ome-POSS is well dispersed in the PPDO matrix. Effect of ome-POSS on the isothermal melt crystallization and dynamic mechanical properties of PPDO in the nanocomposites were studied in detail. It shows that the overall crystallization rates are faster in the nanocomposites than in neat PPDO and increase with the increase in ome-POSS loadings; however, X-ray diffraction patterns, POM and the Avrami exponent suggest that the crystal structure and the crystallization mechanism do not change despite the presence of ome-POSS. The mechanical property of PPDO/ome-POSS nanocomposites was enhanced with respect to neat PPDO.

  20. Effects of Zr, Ti, and Al Additions on Nonmetallic Inclusions and Impact Toughness of Cast Low-Alloy Steel

    Science.gov (United States)

    Bizyukov, Pavel V.; Giese, Scott R.

    2017-03-01

    A microalloying of the low-carbon and low-alloy cast steel was conducted with Zr, Ti, and Al that were added to the steel in four combinations. After heat treatment, the samples were tested for impact toughness at room temperature using the Charpy method. The highest values of impact toughness were obtained in the group treated with Zr, while Zr-Ti and Zr-Ti-Al groups showed moderate toughness values; the lowest values were observed in the Zr-Al group. Difference among the treatment groups was observed in the fracture mechanisms, morphology, and area distribution of the inclusions. High toughness values achieved in the trials treated with zirconium corresponded with smooth ductile fracture. The metal treated with a combination of zirconium and titanium had a relatively small area occupied by inclusions, but its toughness was also moderate. Lowest impact toughness values corresponded with the larger area occupied by the inclusions in the trials treated with aluminum. Also, a connection between the solubility product [Al][N] and impact toughness was established. The study also provides a qualitative description and quantitative analysis of the nonmetallic inclusions formation as a result of microalloying treatment. The precipitation sequence of the inclusions was described based on the thermochemical calculations for the nonmetallic compounds discovered in the experimental steel. A description of the size distribution, morphology, and composition was conducted for the oxides, nitrides, sulfides, and multiphase particles.

  1. Structural and magnetic properties of rapidly quenched and as-cast bulk NdFeBCu alloys

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez Ll, J.L. [Laboratorio de Magnetismo, Facultad de Fisica-IMRE, Universidad de La Habana, Havana 10400 (Cuba)]. E-mail: sanchez@fisica.uh.cu; Bustamante S, R. [Laboratorio de Magnetismo, Facultad de Fisica-IMRE, Universidad de La Habana, Havana 10400 (Cuba); Barthem, V.M.T.S. [Instituto de Fisica, UFRJ, CT, Bloco A, C.P. 68528, 21945-970, Rio de Janeiro (Brazil); Miranda, P.E.V. de [Departamento de Engenharia Metalurgica e de Materiais, COPPE, UFRJ, C.P. 68505, 21945-970, Rio de Janeiro (Brazil)

    2005-07-15

    A study of the structural and magnetic properties of as-cast and melt spun (x)Nd{sub 2}Fe{sub 14}B(100-x)Nd{sub 70}Cu{sub 30} alloys (x=10, 50 and 75%wt.) is presented. In as-cast alloys for x=10wt%. the formation of a high coercivity phase, referred to as N (T{sub C}=240 deg. C, {sub i}H{sub C}=4.9kOe) is found. N is a (Nd-Fe)-based phase with a Fe/Nd ratio lower than that of phase Nd{sub 2}Fe{sub 14}B ({phi}). It is suggested that this phase is related to the A{sub 1} phase found in binary Nd-Fe alloys. In melt-spun alloys, at the same x value of 10wt%, another hard phase is found which is suggested to be the Nd{sub 6}Fe{sub 13}Cu {delta}-phase (T{sub C}=192 deg. C, {sub i}H{sub C}=4.8kOe). Transmission electron microscope (TEM) micrographs of the ribbons with x=10wt% shows the formation of nanograins with a non-uniform grain size distribution. In cast alloys with x=50 and 75wt% large slab-like grains of {phi} are formed, in the inter-granular region a Nd-Cu eutectic phase and Nd grains, are observed. High coercivities are obtained in ribbons with x=50wt% ({sub i}H{sub C}=19.7kOe) and 75wt% ({sub i}H{sub C}=13.0kOe). A slight reduction in the Curie temperature of the {phi}-phase with respect to the bulk value is found in these ribbons.

  2. Optimization of pulsed Nd:YAG laser melting of gray cast iron at different spot sizes for enhanced surface properties

    Science.gov (United States)

    Zulhishamuddin, A. R.; Aqida, S. N.; Rahim, E. A.

    2016-10-01

    This paper presents a laser surface modification process of gray cast iron using different laser spot size with an aims to eliminate graphite phase and achieve minimum surface roughness and maximum depth of molten zone and microhardness properties. The laser processing was conducted using JK300HPS Nd:YAG twin lamp laser source pulse TEM00 mode, 50 W average power, 1064 nm wavelength and different laser spot sizes of 1.0 mm, 1.2 mm, 1.4 mm and 1.7 mm. Three controlled parameter were peak power (Pp), pulse repetition frequency (PRF) and traverse speed (v). Increasing spot size the parameter setting where peak power is increased and pulse repetition frequency and traverse speed is decreased. The modified surface of laser surface melting was characterized for metallographic study, surface roughness and hardness. Metallographic study and surface morphology were conducted using optical microscope while hardness properties were measured using Vickers scale. Surface roughness was measured using a 2D stylus profilometer. From metallographic study, the graphite phase was totally eliminated from the molten zone and formed white zone. This phenomenon affected hardness properties of the modified surface where maximum hardness of 955.8 HV0.1 achieved. Optimization of laser surface modification was conducted for minimum surface roughness and maximum depth of modified layer and hardness properties. From the optimization, the higher desirability is 0.902. The highest depth of molten zone obtain from spot size 1.4 mm at 132 µm and the highest hardness is 989 HV0.1 at laser's spot size 1.0 mm. The surface roughness increased when the spot size increased from 3.10 µm to 7.31 µm. These finding indicate potential application of enhanced gray cast iron in high wear resistance automotive components such as cylinder liner and break disc.

  3. Inoculation of chromium white cast iron

    Directory of Open Access Journals (Sweden)

    D. Kopyciński

    2009-01-01

    Full Text Available It has been proved that an addition of boron carbide introduced as an inoculant to the chromium white cast iron changes the structureof castings. Castings after inoculation revealed a different structure with numerous grains. Primary precipitates of chromium carbide also appeared, reducing the mechanical properties of as-cast parts. Properly established heat treatment regime makes chromium iron castings regain their, originally high, mechanical properties.

  4. New Approaches to Aluminum Integral Foam Production with Casting Methods

    Directory of Open Access Journals (Sweden)

    Ahmet Güner

    2015-08-01

    Full Text Available Integral foam has been used in the production of polymer materials for a long time. Metal integral foam casting systems are obtained by transferring and adapting polymer injection technology. Metal integral foam produced by casting has a solid skin at the surface and a foam core. Producing near-net shape reduces production expenses. Insurance companies nowadays want the automotive industry to use metallic foam parts because of their higher impact energy absorption properties. In this paper, manufacturing processes of aluminum integral foam with casting methods will be discussed.

  5. Role of Titanium in Thin Wall Vermicular Graphite Iron Castings Production

    Directory of Open Access Journals (Sweden)

    M. Górny

    2013-04-01

    Full Text Available In this paper the effects of titanium addition in an amount up to 0.13 wt.% have been investigated to determine their effect on the microstructure and mechanical properties of Thin Wall Vermicular Graphite Iron Castings (TWVGI. The study was performed for thinwalled iron castings with 3-5 mm wall thickness and for the reference casting with 13 mm. Microstructural changes were evaluated by analyzing quantitative data sets obtained by image analyzer and also using scanning electron microscope (SEM. Metallographic examinations show that in thin-walled castings there is a significant impact of titanium addition to vermicular graphite formation. Thinwalled castings with vermicular graphite have a homogeneous structure, free of chills, and good mechanical properties. It may predispose them as a potential use as substitutes for aluminum alloy castings in diverse applications.

  6. 石蜡含量对浇铸尼龙材料摩擦磨损性能的影响%Effect of Paraffin Content on Friction and Wear Properties of Casting Nylon Materials

    Institute of Scientific and Technical Information of China (English)

    黄建龙; 杨玉青; 党兴武; 王建吉; 王彦芳

    2013-01-01

      采用石蜡对起重机伸缩臂滑块用的浇铸尼龙材料进行改性,用MRH-3高速环块摩擦磨损试验机和RFT-Ⅲ往复式摩擦磨损试验机,研究不同石蜡含量对浇铸尼龙材料干摩擦磨损性能的影响。结果表明:石蜡的填充对改善浇铸尼龙材料力学性能和摩擦磨损性能有显著作用;石蜡含量的增加,浇铸尼龙材料的摩擦因数呈现先下降后上升的变化趋势,存在最佳的添加量,使材料的摩擦因数和磨损量最低。%The paraffin was used to modify cast nylon material for cranes telescopic boom slider,and the impacts of different paraffin content on the dry friction and wear properties of the cast nylon material were researched by using MRH-3 high-speed ring block friction and wear testing machine and RFT-Ⅲreciprocating friction and wear testing machine. The results show that:filling paraffin can improve mechanical properties,the friction and wear properties of the casting nylon material significantly. When paraffin content is increased,the friction coefficient of cast nylon material presents the trend of decreasing first and then increasing. There are optimal added amount,making the friction coefficient and the wear quantity to minimum.

  7. THE IMPACT OF STRUCTURAL, PETROGRAPHIC AND CLIMATIC FACTORS ON THE SLOPE STABILITY IN THE OPEN CAST MINE OF GRADNA

    Directory of Open Access Journals (Sweden)

    Ivan Tomašić

    1992-12-01

    Full Text Available This paper presents an analysis of a complexity of interrelated structural, petrologic and climatic factors that considerably affect the instabilities in the open cast mine of Gradna, near Samobor. The instabilities provoke the slope failures such as slides and slumps of rock material. During the protracted periodical investigations, the relationship among the factors of regional geology, tectonics, structural geology, petrography, engineering geology, rock mechanics and the rock mining technology was observed in the area. The local control of hydrogeologic properties, as well as climatic fluctuations of temperature and precipitation on the slope stability, was also recognized. It turned out that the structural relationships, characteristic of the manifold cataclased dolomite, stimulated the development of local instabilities, particularly during the period of low temperatures affecting the process of ground-water accumulation. When the temperatures are worm, the ground-water circulation is slow, exerting only the small-scale influence on the local instabilities (the paper is published in Croatian.

  8. Microstructure and Mechanical Properties After Shock Wave Loading of Cast CrMnNi TRIP Steel

    Science.gov (United States)

    Eckner, Ralf; Krüger, L.; Ullrich, C.; Rafaja, D.; Schlothauer, T.; Heide, G.

    2016-10-01

    The mechanical response of shock wave-prestrained high-alloy Cr16-Mn7-Ni6 TRIP steel was investigated under compressive and tensile loading at room temperature. Previous shock wave loading was carried out using a flyer-plate assembly with different amounts of explosives in order to achieve shock pressures of 0.3, 0.6, 0.9, and 1.2 Mbar. A significant increase in hardness and strength was observed as compared with the initial as-cast condition. In contrast, a slight decrease in strain hardening rates was measured together with a decrease in fracture elongation in the tensile test. Microstructural analyses of the shock-loaded samples were performed by light optical and scanning electron microscopy. The microstructure revealed a high density of deformation bands consisting of separated stacking faults, ɛ-martensite, or twins. Significant amounts of deformation-induced α'-martensite were only present at the highest shock pressure of 1.2 Mbar. The thickness of the deformation bands and the number of martensite nuclei at their intersections increased with increasing shock pressure. In all shock-loaded specimens, pronounced phase transformation occurred during subsequent mechanical testing. Consequently, the amount of the deformation-induced α'-martensite in the shock-loaded specimens was higher than in the unshocked as-cast samples.

  9. Properties of polylactide inks for solvent-cast printing of three-dimensional freeform microstructures.

    Science.gov (United States)

    Guo, Shuang-Zhuang; Heuzey, Marie-Claude; Therriault, Daniel

    2014-02-01

    Solvent-cast printing is a highly versatile microfabrication technique that can be used to construct various geometries such as filaments, towers, scaffolds, and freeform circular spirals by the robotic deposition of a polymer solution ink onto a moving stage. In this work, we have performed a comprehensive characterization of the solvent-cast printing process using polylactide (PLA) solutions by analyzing the flow behavior of the solutions, the solvent evaporation kinetics, and the effect of process-related parameters on the crystallization of the extruded filaments. Rotational rheometry at low to moderate shear rates showed a nearly Newtonian behavior of the PLA solutions, while capillary flow analysis based on process-related data indicated shear thinning at high shear rates. Solvent vaporization tests suggested that the internal diffusion of the solvent through the filaments controlled the solvent removal of the extrudates. Different kinds of three-dimensional (3D) structures including a layer-by-layer tower, nine-layer scaffold, and freeform spiral were fabricated, and a processing map was given to show the proper ranges of process-related parameters (i.e., polymer content, applied pressure, nozzle diameter, and robot velocity) for the different geometries. The results of differential scanning calorimetry revealed that slow solvent evaporation could increase the ability of PLA to complete its crystallization process during the filament drying stage. The method developed here offers a new perspective for manufacturing complex structures from polymer solutions and provides guidelines to optimize the various parameters for 3D geometry fabrication.

  10. Microstructures and Magnetic Properties of As-Cast RE(Dy)-Fe-C(B) Alloys

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    High coercivity was obtained in bulk RE(Dy)-Fe-C(B) alloys with RE=Nd, Pr and Mm. In the as-cast state, the samples show a negligible coercivity Hci. Magnetic hardening takes place when annealing the as-cast alloys at around 1173 K for several hours, which produces an Hci greater than 1200 kA*m-1. Boron appears to be very important for achieving high coercivity, which is found to increase with increasing Dy content. SEM studies show a very small grain size at around 2 μm. X-ray diffraction and TEM studies reveal the existence of multiphases after annealing. They are RE2Fe14(B,C), RE2Fe3Cx, alpha-Fe(RE) and RE2Fe17(B,C) in order of their amounts. The carbide RE2Fe3Cx has a complicated hexagonal structure with a=0.468 nm and c=0.795 nm.

  11. Development of high toughness in austempered type ductile cast iron and evaluation of its properties

    Science.gov (United States)

    Kobayashi, Toshiro; Yamamoto, Hironobu

    1988-02-01

    In order to increase the toughness of austempered ductile cast irons, we attempted to strengthen the fracture initiation sites such as graphite-matrix interfaces and eutectic cell boundaries in a way of the microsegregation of alloying elements. For instance, the retained austenite which is stable under external stresses may be introduced preferentially into these sites by the addition of Ni, which segregates to a graphite periphery and of Mn, which partitions mainly to eutectic cell boundaries. Following this concept, the effects of various austempering processes on toughness are also in-vestigated. The cast iron alloying with Ni and Mn shows the best fracture toughness when it is heat-treated by either QB' or B' process; here, the QB' means the oil-quenching from an austenite γ phase range followed by austempering from a ferrite α plus γ range and the B' means austempering from a (α + γ) range. In the newly developed iron, there is a mixed microstructure composed of the ferrite, bainitic ferrite, and austenite. Abnormal elongation due to the TRIP effect in the austenite phase is found to have occurred at about 198 K. Moreover, it is shown that this TRIP effect may be caused by the formation of deformation twins.

  12. The Mechanical Properties of ALCA PlusTM Cast Aluminum Amplifier Top Plates

    Energy Technology Data Exchange (ETDEWEB)

    Biltoft, P; Gourdin, W H; Sanchez, R J; Shen, T H

    2002-06-27

    The amplifier top plates are monolithic, cast aluminum structures from which the amplifier frame assembly units (FAUs), and the line-replaceable flash lamp units (LRUs) inside them, are hung on the support rails in the laser bays. When fully assembled, each plate must support a static weight of 10,600 or 16,000 pounds, depending upon whether two or three loaded FAUs are attached. The top plates are fabricated from ''ALCA Plus{trademark}'', a zinc-containing aluminum casting alloy similar in composition to some standard alloys in the 7000-series. For electrical reasons, all of the plate with the exception of the support ''ears'', is encased in epoxy as shown in Figure 1. The nominal chemistry of the aluminum alloy is summarized in Table 1 and the nominal mechanical characteristics are summarized in Table 2. For comparison, wrought alloys of similar composition in the 7000-series have ultimate strengths of approximately 33-76 ksi and elongations of 11-17%, depending upon the temper.

  13. Effects of selected casting methods on mechanical behaviour of Al-Mg-Si alloy

    Directory of Open Access Journals (Sweden)

    Henry Kayode TALABI

    2014-11-01

    Full Text Available This study investigated the effects of selected casting methods on mechanical behaviour of Al-Mg-Si alloy. The casting methods used was spin, sand and die casting, these were done with a view to determine which of the casting methods will produce the best properties. The pure aluminium scrap, magnesium and silicon were subjected to chemical analysis using spectrometric analyzer, thereafter the charge calculation to determine the amount needed to be charged into the furnace was properly worked out and charged into the crucible furnace from which as-cast aluminium was obtained. The mechanical properties of the casting produced were assessed by hardness and impact toughness test. The optical microscopy and experimental density and porosity were also investigated. From the results it was observed that magnesium and silicon were well dispersed in aluminium matrix of the spin casting. It was observed from visual examination after machining that there were minimal defects. It was also observed that out of the three casting methods, spin casting possesses the best mechanical properties (hardness and impact toughness.

  14. Effect of Friction Stir Processing on Microstructure and Mechanical Properties of AZ91C Magnesium Cast Alloy Weld Zone

    Science.gov (United States)

    Hassani, Behzad; Karimzadeh, Fathallah; Enayati, Mohammad Hossein; Sabooni, Soheil; Vallant, Rudolf

    2016-07-01

    In this study, friction stir processing (FSP) was applied to the GTAW (TIG)-welded AZ91C cast alloy to refine the microstructure and optimize the mechanical properties of the weld zone. Microstructural investigation of the samples was performed by optical microscopy and the phases in the microstructure were determined by x-ray diffraction (XRD). The microstructural evaluations showed that FSP destroys the coarse dendritic microstructure. Furthermore, it dissolves the secondary hard and brittle β-Mg17Al12 phase existing at grain boundaries of the TIG weld zone. The closure and decrease in amount of porosities along with the elimination of the cracks in the microstructure were observed. These changes were followed by a significant grain refinement to an average value of 11 µm. The results showed that the hardness values increased to the mean ones, respectively, for as-cast (63 Hv), TIG weld zone (67 Hv), and stir zone (79 Hv). The yield and ultimate strength were significantly enhanced after FSP. The fractography evaluations, by scanning electron microscopy (SEM), indicated to a transition from brittle to ductile fracture surface after applying FSP to the TIG weld zone.

  15. Simulation of Heat Flow in Computational Method and Its Verification on the Structure and Property of Gray Cast Iron

    Directory of Open Access Journals (Sweden)

    S. K. Shaha

    2010-01-01

    Full Text Available Problem statement: The solidification of materials depends on the cooling rate of the materials which is governed by heat flow in the mould and alloy composition. Solidification rate also affects the structure and properties of the materials. Approach: In the present study, the heat flow of cold set resin bonded sand mould was simulated using JL Analyzer FEM analysis software. To verify the model, the gray cast iron was melted at 1350°C temperature and poured into a resin bonded sand mould at 1300°C. Results: It showed that most of the heat-reserve at the junction of the mould which was nearer to the source of liquid metal and the lowest heat-reserve at the end of the mould. So, the solidification rate was very high at the end of the mould wall whereas it was comparatively low near the sprue of the mould. Conclusion: Finally, depending on the heat-flow through the mould, the solidification rate changed the microstructure from chill, mottled and gray cast iron and hardness changed from 95.1 HRB-78.78 HRB.

  16. Mechanical properties and constitutive behaviors of as-cast 7050 aluminum alloy from room temperature to above the solidus temperature

    Institute of Scientific and Technical Information of China (English)

    Qing-ling Bai; Hong-xiang Li; Qiang Du; Ji-shan Zhang; Lin-zhong Zhuang

    2016-01-01

    The mechanical properties and constitutive behaviors of as-cast AA7050 in both the solid and semi-solid states were determined using the on-cooling and in situ solidification approaches, respectively. The results show that the strength in the solid state tends to increase with decreasing temperature. The strain rate plays an important role in the stress–strain behaviors at higher temperatures, whereas the influ-ence becomes less pronounced and irregular when the temperature is less than 250°C. The experimental data were fitted to the extended Ludwik equation, which is suitable to describe the mechanical behavior of the materials in the as-cast state. In the semi-solid state, both the strength and ductility of the alloy are high near the solidus temperature and decrease drastically with decreasing solid fraction. As the solid fraction is less than 0.97, the maximum strength only slightly decreases, whereas the post-peak ductility begins to increase. The experimental data were fitted to the modified creep law, which is used to describe the mechanical behavior of semi-solid materials, to determine the equivalent parameter f GBWL, i.e., the fraction of grain boundaries covered by liquid phase.

  17. Effect of rolling deformation and solution treatment on microstructure and mechanical properties of a cast duplex stainless steel

    Indian Academy of Sciences (India)

    S K Ghosh; D Mahata; R Roychaudhuri; R Mondal

    2012-10-01

    The present study deals with the effect of rolling deformation and solution treatment on the microstructure and mechanical properties of a cast duplex stainless steel. Cast steel reveals acicular/Widmanstätten morphology as well as island of austenite within the -ferrite matrix. Hot rolled samples exhibit the presence of lower volume percent of elongated band of -ferrite (∼40%) and austenite phase which convert into finer and fragmented microstructural constituents after 30% cold deformation. By the solution treatment, the elongated and broken crystalline grains recrystallize which leads to the formation of finer grains (<10 m) of austenite. X-ray diffraction analysis has corroborated well with the above-mentioned microstructural investigation. Enhancement in hardness, yield strength and tensile strength values as well as drop in percent elongation with cold deformation increases its suitability for use in thinner sections. 30% cold rolled and solution treated sample reveals attractive combination of strength and ductility (25.22 GPa%). The examination of fracture surface also substantiates the tensile results. The sub-surface micrographs provide the potential sites for initiation of microvoids.

  18. Clean Metal Casting

    Energy Technology Data Exchange (ETDEWEB)

    Makhlouf M. Makhlouf; Diran Apelian

    2002-02-05

    The objective of this project is to develop a technology for clean metal processing that is capable of consistently providing a metal cleanliness level that is fit for a given application. The program has five tasks: Development of melt cleanliness assessment technology, development of melt contamination avoidance technology, development of high temperature phase separation technology, establishment of a correlation between the level of melt cleanliness and as cast mechanical properties, and transfer of technology to the industrial sector. Within the context of the first task, WPI has developed a standardized Reduced Pressure Test that has been endorsed by AFS as a recommended practice. In addition, within the context of task1, WPI has developed a melt cleanliness sensor based on the principles of electromagnetic separation. An industrial partner is commercializing the sensor. Within the context of the second task, WPI has developed environmentally friendly fluxes that do not contain fluorine. Within the context of the third task, WPI modeled the process of rotary degassing and verified the model predictions with experimental data. This model may be used to optimize the performance of industrial rotary degassers. Within the context of the fourth task, WPI has correlated the level of melt cleanliness at various foundries, including a sand casting foundry, a permanent mold casting foundry, and a die casting foundry, to the casting process and the resultant mechanical properties. This is useful in tailoring the melt cleansing operations at foundries to the particular casting process and the desired properties of cast components.

  19. Relationships between microstructure and mechanical properties in ductile cast irons: a review; Relaciones entre la microestructura y las propiedades mecanicas en fundiciones nodulares: revison bibliografica

    Energy Technology Data Exchange (ETDEWEB)

    Castillo, R.; Bermont, V. [Universidad de La Serena. La Serena. Chile (Chile); Martinez, V. [Universidad de Santiago. Santiago Chile (Chile)

    1999-07-01

    The progress achieved in the understanding of the relationships between the microstructure and the mechanical properties of ductile cast iron is reviewed. It is also described the applications of heat treatment of austempered to ductile irons (ADI), which have allowed to improve substantially the mechanical properties of these materials. It is proposed a research program to obtain the crack growth resistance under corrosive atmospheres and to model the mechanical properties. (Author) 83 refs.

  20. Effects of silicon content and austempering condition on the impact characteristics of austempered ductile cast iron. Kyojin kyujo kokuen chutetsu no jinsei ni oyobosu osutenpa shori joken to Si ryo no eikyo

    Energy Technology Data Exchange (ETDEWEB)

    Aoyama, M. (Daido Inst. of Technology, Nagoya (Japan)); Kobayashi, T. (Toyohashi Univ. of Technology, Aichi (Japan)); Matsuo, K. (Kurimoto Iron Works, Ltd., Osaka (Japan))

    1990-07-25

    Austempered spherical graphite cast iron (ADI) is extensively expeted as a mechanical structural material because of high tenacity and resilience as well as fatigue strength and wear resistance. These excellent properties are attributed to the abundantly remaining austenite because the formation of carbides is restricted by the action of the silicon element. It is, therefore, important for obtaining the strong cast iron material to control the amount of the retained austenite. In this study, the impact characteristics was investigated for acquiring the basic materials concerning the influence of the temperature, time of austempering and the amount of silicon. The added amount of silicon is most suitably 2.1%. Samples without Mn and Ni showed an impact value of about 2 times of the amount added. At 400 {degree} C, however, the impact value reduced to half by the growth of coarse ferrite and bentonite. Time of austempering was 1 hour and showed a stable impact value and load of breaking. Transition temperature shifted tolow side by the increase of amount of silicon. 14 refs., 10 figs., 1 tab.

  1. Preparation and mechanical properties of SiC/2024 composite by semisolid casting

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A SiC/2024 composite was made by semisolid casting. The wetting between SiC and Al matrix is improved by treating SiC particles at a high temperature, coating K2ZrF6, and adding Mg to the Al melt. An effective way to remove the gas around SiC particles was also found. Microsturctures were observed under optical microscope (OM) and scanning electron microscopy (SEM). The results show that SiC particles and Al matrix are well bonded and no gaps or cavities around the particles are observed. SiC particles distribute homogeneously in the Al matrix. The existence of SiC particles results in the increase of wear resistance and strength.

  2. Effect of Welding Parameters on Microstructure and Mechanical Properties of Cast Fe-40Al Alloy

    Directory of Open Access Journals (Sweden)

    Osman Torun

    2016-09-01

    Full Text Available Friction welding of cast Fe-40Al alloy was carried out at 1000 rmp for various friction times, friction pressures, and forging pressures. The microstructures of the interface of welded samples were analyzed by optical and scanning electron microscopy (SEM. Micrographs demonstrated that excellent welding formed continuously along the interface, except for samples welded for 3 s. Chemical compositions of the interface of the friction welded samples and of the fractured surface of all the specimens were determined using energy dispersive spectroscopy (EDS. After the welding process, shear tests were applied to the welded samples to determine the shear strength of joints. Test results indicated that the maximum shear strength was 469.5 MPa.

  3. Property Characteristics of a TiB2P/AI Composite Fabricated by Squeeze Casting Technology

    Institute of Scientific and Technical Information of China (English)

    Min ZHAO; Gaohui WU; Zuoyong DOU; Longtao JIANG

    2006-01-01

    TiB2P/Al composite was successfully fabricated by squeeze casting technology. Its mechanical and tribological properties were evaluated. The elimination of Ti-Al intermetallic compound was confirmed by X-ray diffraction (XRD) studies. At 45% volume fraction, the bending strength at ambient temperature was 934 MPa. And the fracture modes included ductile failure of Al matrix and brittle fracture of TiB2 particles. In dry sliding wear mode, severe plastic deformation and adhesive wear were found on the worn surfaces of the SiCP/Alcomposite. But no obvious characteristics of adhesion or abrasion wear were observed on that of the TiB2P/Al composites. At the steady stage, the friction coefficient of the SiCP/Al composite was about 0.6. While that of TiB2P/Al composite was only about 0.16~0.17.

  4. Preparation and thermomechanical properties of stir cast Al–2Mg–11TiO2 (rutile) composite

    Indian Academy of Sciences (India)

    S K Chaudhury; A K Singh; C S S Sivaramakrishnan; S C Panigrahi

    2004-12-01

    Al–2Mg–11TiO2 composite was successfully prepared by the conventional vortex method. The macrostructural observation revealed columnar structure with rutile particles being distributed throughout the matrix in the form of agglomerates. Microstructural observation showed the presence of micro voids in the particle-enriched zone. Electrical resistivity measurement showed a phase transformation at 360°C, which was consistent during DSC studies due to the precipitation of TiAl3 phase. As-cast composite was both hot rolled and cold rolled successfully to 50 and 40% reduction, respectively. The mechanical properties of the thermomechanically-worked composite were studied. From fractographic analysis, it was clear that the crack had nucleated at the particle/matrix interface and propagated through the matrix by microvoid coalescence. Ultimate tensile strength of cold worked composite was found to be better than the hot worked material.

  5. Effect of particle size on thermo-physical properties of SiCp/Cu composites fabricated by squeeze casting

    Institute of Scientific and Technical Information of China (English)

    WU Gao-hui; CHEN Guo-qin; ZHU De-zhi; ZHANG Qiang; JIANG Long-tao

    2005-01-01

    For the electronic packaging applications, copper matrix composites reinforced with different sized SiC particles (10 μm, 20 μm and 63 μm) were fabricated by squeeze casting technology. And the effect of particle size on their thermo-physical properties was discussed. The composites are free of porosity and the SiC particles are distributed uniformly in the composites. It is found that the mean linear thermal expansion coefficients(20 - 100 ℃ ) of SiCp/Cu composites are in the range of (8.4 - 9.2) × 10-6/℃, and smaller expansion coefficient can be obtained for the composites with finer SiC particles because of the larger restriction in expansion through interfaces. Their thermal conductivities are reduced with the decrease of SiC sizes. This is attributed to the fact that the negative effect of interfacial thermal resistance becomes increasingly dominant as the particles becomes smaller.

  6. Preparation and properties of multi-wall carbon nanotube/SiC composites by aqueous tape casting

    Institute of Scientific and Technical Information of China (English)

    L(U) ZhiHui; JIANG DongLiang; ZHANG JingXian; LIN QingLing

    2009-01-01

    MWCNTS/SiC composites were fabricated by aqueous tape casting. High solid content (50 vol%) SiC slurries with sintering additives and multi-wall carbon nanotubes (MWCNTs) as reinforcements were prepared using Tetramethylammonium hydroxide as the dispersant. The stability of MWCNTs/SiC slur-ries was studied and characterized in terms of zeta potential and rheology measurements. The relative density of the composite was about 98% after hot-pressing at 1850℃ (at 25 MPa in Ar for 30 min). The hardness of the composites decreased with the increase in MWCNTs content, The flexural strength and was 0,25 wt%. Further increase in MWCNTs content to 0.50 wt% did not lead to the increase in me-chanical properties. Most of MWCNTs were found to be located at SiC grain boundaries and the pull out of the MWCNTs was observed.

  7. Colour Metallography of Cast Iron

    Institute of Scientific and Technical Information of China (English)

    Zhou Jiyang; Liu Jincheng

    2010-01-01

    @@ Chapter 3 Spheroidal Graphite Cast Iron(I) Spheroidal Graphite Cast Iron, SG iron in short, refers to the cast iron in which graphite precipitates as spheroidal shape during solidification of liquid iron. The graphite in common commercial cast iron can only be changed from flake to spheroidal shape by spheroidising treatment. Since spheroidal graphite reduces the cutting effect of stress concentration, the metal matrix strength of SG iron can be applied around 70%-90%, thus the mechanical property of SG iron is significantly superior to other cast irons;even the tensile strength of SG iron is higher than that carbon steel.

  8. 浇铸无烟CMDB推进剂流变性能%Rheological Properties of Cast Smokeless CMDB Propellants

    Institute of Scientific and Technical Information of China (English)

    蔚红建; 樊学忠; 付小龙; 滕学峰; 孟玲玲; 张伟; 谢五喜

    2012-01-01

    In order to regulate the rheological properties of cast smokeless composite modified double based (CMDB) propellants composed of nitrocellulose, nitroglycerin and clotrimethylene-trinitramine, the influences of plasticizer, rheological modifier and temperature on the rheological properties of cast CMDB propellants were studied by a HAAKE rotational viscometer. The results show that CMDB propellants are pseudoplastic fluid with yield stress. By adjusting the ratio between plasticizer nitroglycerin and DINA (m( NG) : m( DINA) =10 : 1 ,8 : 1 ,6 : 1 ) ,with specific plasticizer reduces,the viscosity and yield of CMDB propellants increase and the flow activation energy decreases. With the increasing in rheological modifier content, the viscosity of CMDB propellants increases obviously,and the flow activation energy decreases. The viscosity of CMDB propellants decreases at higher temperatures.%为有效调节改性双基(CMDB)推进剂(主要组分为硝化棉、硝化甘油和黑索今)的流变性能,利用HAAKE旋转流变仪研究了增塑剂、高分子增稠剂及温度对CMDB推进剂流变特性的影响.结果表明,CMDB推进剂为具有屈服应力的假塑性流体,调整增塑剂硝化甘油与吉纳的比例(m(NG)∶m(DINA) =10∶1,8∶1,6∶1),当增塑剂比例降低,CMDB推进剂粘度和屈服值增大,流动活化能减小;高分子增稠剂含量增加,CMDB推进剂粘度明显增大,流动活化能减小;温度升高,CMDB推进剂粘度减小.

  9. Cast irons

    CERN Document Server

    1996-01-01

    Cast iron offers the design engineer a low-cost, high-strength material that can be easily melted and poured into a wide variety of useful, and sometimes complex, shapes. This latest handbook from ASM covers the entire spectrum of one of the most widely used and versatile of all engineered materials. The reader will find the basic, but vital, information on metallurgy, solidification characteristics, and properties. Extensive reviews are presented on the low-alloy gray, ductile, compacted graphite, and malleable irons. New and expanded material has been added covering high-alloy white irons used for abrasion resistance and high-alloy graphitic irons for heat and corrosion resistance. Also discussed are melting furnaces and foundry practices such as melting, inoculation, alloying, pouring, gating and rising, and molding. Heat treating practices including stress relieving, annealing, normalizing, hardening and tempering, autempering (of ductile irons), and surface-hardening treatments are covered, too. ASM Spec...

  10. Energy Saving Melting and Revert Reduction (E-SMARRT): Optimization of Heat Treatments on Stainless Steel Castings for Improved Corrosion Resistance and Mechanical Properties

    Energy Technology Data Exchange (ETDEWEB)

    John N. DuPont; Jeffrey D. Farren; Andrew W. Stockdale; Brett M. Leister

    2012-06-30

    It is commonly believed that high alloy steel castings have inferior corrosion resistance to their wrought counterparts as a result of the increased amount of microsegregation remaining in the as-cast structure. Homogenization and dissolution heat treatments are often utilized to reduce or eliminate the residual microsegregation and dissolve the secondary phases. Detailed electron probe microanalysis (EPMA) and light optical microscopy (LOM) were utilized to correlate the amount of homogenization and dissolution present after various thermal treatments with calculated values and with the resultant corrosion resistance of the alloys.The influence of heat treatment time and temperature on the homogenization and dissolution kinetics were investigated using stainless steel alloys CN3MN and CK3MCuN. The influence of heat treatment time and temperature on the impact toughness and corrosion reistance of cast stainless steel alloys CF-3, CF-3M, CF-8, and CF-8M was also investigated.

  11. Effect of Ce-rich misch metal addition on squeeze cast microstructure and mechanical properties of AZ81 alloy

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The effect of cerium-rich misch metal addition on the microstructure and properties of squeeze cast magnesium alloys AZ81 was empirically investigated. The results indicate that the addition of cerium-rich misch metal modifies the microstructure gradually. With the increase of the RE addition, the amount of Mg17Al12 decreases while that of Al11(RE)3 increases, accompanied by grain refinement. When the addition reaches 1.5%, the grain refinement becomes obvious. However, when the addition exceeds 2.0%,Al11(RE)3 phase coarsens into rod shape and the grain size increases. The tensile properties of the AZ81 at both room temperature and 150℃ increase with the addition, and reach their optimal values with the addition of 1.5%. Further increase of the addition to above 2.0% decreases the tensile properties considerably. The tensile fracture of the alloy is characterized by the cleavage of the brittle second phases and ductile dimples of the matrix.

  12. Phase composition, structure and properties of cast Ti-Si-Sn-Al alloys

    Energy Technology Data Exchange (ETDEWEB)

    Bulanova, M.; Ban' kovsky, O.; Soroka, A.; Samelyuk, A.; Tretyachenko, L.; Kulak, L.; Firstov, S. [AN Ukrainskoj SSR, Kiev (Ukraine). Inst. Problem Materialovedeniya

    2000-01-01

    By the methods of X-ray, microscopic and electron microprobe analysis the phase compositions of Ti-rich as-cast Ti-Si-Sn-Al alloys were studied. Projections of the solidus and liquidus surfaces at three Si/Sn ratios (9Si-1Sn, 7Si-3Sn, 5Si-5Sn in at.%) are discussed. The projections are similar to that for the Ti-Si-Al system, and differ in the width of the homogeneity range of the coexisting phases. Microhardness of the constituents (transformed {beta}-Ti, Ti{sub 5} (Si,Sn, Al){sub 3}) (Z) and eutectic ({beta}+Z) was measured. The results are discussed on the basis of the above projections. Long-term and hot hardness of the alloys were examined. They strongly depend on the relative tin content in the alloys. All the alloys studied show higher strength at elevated temperature than VT-18 alloy. The alloy 75Ti-5Si-5Sn-15Al seems to be prospective in respect to workability. (orig.)

  13. Study on Properties of LSGM Electrolyte Made by Tape Casting Method and Applications in SOFC

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Solid oxide fuel cell is attracting more attention in recent years for its lower pollution emission and high energy convert efficiency. La0.9Sr0.1Ga0.8Mg0.2O3-δ is a new kind of electrolyte for intermediate temperature SOFC. In this paper, La0.9Sr0.1Ga0.8Mg0.2O3-δ (LSGM) was prepared by solid state reaction method and formed by tape casting process to make a planar electrolyte. The appropriate amount of the dispersive was obtained by viscosity test. The densities of sintered samples increase with the increasing sintering temperature. It was found that the relative density of electrolyte can approach the value of 95% by the isostatic pressing treatment of the green tape. The average thermal expansion coefficient of the LSGM is 11.4×10-6/℃ at temperature range (200~1200 ℃). Measurements of the current-voltage and power-current characteristics of the H2-Air cell show that the open-circuit voltage is 1.067 V at 800 ℃, peak current density is 0.56 A·cm-2 and the maximum power output is 0.147 W·cm-2.

  14. Microstructural characteristics and properties in centrifugal casting of SiC_p/Zl104 composite

    Institute of Scientific and Technical Information of China (English)

    WANG Kai; XUE Han-song; ZOU Mao-hua; LIU Chang-ming

    2009-01-01

    The microstructural characteristics and Brinell hardness of a cylinder produced by centrifugal casting were investigated using 20% (volume fraction) SiC_p/Zl104 composites.Macrostructure and XRD analysis show that most of SiC particles segregate to the external circumference of the cylinder,the other SiC particles maintain in the inner circumference of the cylinder,and a free particle zone is left in the middle circumference of the cylinder.Microstructural characteristics and quantitative assessment of SiC particles show that most of congregated SiC particles in 20%SiC_p/Zl104 composites are dispersed by centrifugal force,and the other congregated SiC particles and most of alumina oxide are segregated to the inner circumference of the cylinder.The SiC particles in aluminum melt can promote the refinement of primary α(Al) during solidification,and fine primary α(Al) grains can also promote the uniform distribution of SiC particles.Brinell hardness of SiC_p/Zl104 composites is connected with not only the volume fraction of SiC particles,but also the distribution of SiC particles in matrix alloy.

  15. Microstructure and Wear Properties of Electron Beam Melted Ti-6Al-4V Parts: A Comparison Study against As-Cast Form

    Directory of Open Access Journals (Sweden)

    Wei Quan Toh

    2016-11-01

    Full Text Available Ti-6Al-4V (Ti64 parts of varying thicknesses were additively manufactured (AM by the powder-bed-based electron beam melting (EBM technique. Microstructure and wear properties of these EBM-built Ti-6Al-4V parts have been investigated in comparison with conventionally cast Ti64 samples. Sliding wear tests were conducted using a ball-on-disc micro-tribometer under ambient conditions. Experimental results reveal that EBM-built Ti64 samples exhibited higher microhardness and an overall larger coefficient of friction as compared to the as-cast counterpart. Of interest is that the corresponding specific wear volumes were lower for EBM-built Ti64 samples, while the as-cast Ti64 showed the poorest wear resistance despite its lower coefficient of friction. Wear mechanisms were provided in terms of quantitative microstructural characterization and detailed analysis on coefficient of friction (COF curves.

  16. Rheo-Cast Microstructure and Mechanical Properties of AM60 Alloy Produced by Self-Inoculation Rheo-Diecasting Process

    Directory of Open Access Journals (Sweden)

    Bo Xing

    2016-03-01

    Full Text Available Rheo-forming is becoming the choice for production of high quality parts with diminished defects and fine integrity. In this paper, the novel self-inoculation rheo-diecasting (SIRD process, in which semisolid slurry is produced by mixing two precursory solid and liquid alloys and subsequently pouring them through a multi-stream fluid director, has been proposed. Microstructural characteristics of AM60 alloy slurry and the microstructure and mechanical properties of rheo-diecasting AM60 samples were investigated. Quenching experiments reveal that the slurry microstructure of AM60 was well refined to irregular α-Mg particles with the average size of approximately 20–40 μm after pouring with the self-inoculation process, and these particles were evolved to globular and coarse morphology while continuously keeping in semisolid state. After rheo-diecasting, the microstructure of the sample was dominated by fine primary α-Mg globules accompanied with tiny secondary α-Mg particles while the sample from conventional liquid die casting was characterized by developed dendrite and porosity. Microscopic analysis indicates that there are three stages of remaining liquid solidification in die cavity in SIRD: α-Mg nucleation and growth on primary α-Mg surface, α-Mg nucleated independently in liquid, and, finally, formation of skeleton devoiced eutectic. Due to diminished porosity and hot tearing, tensile strength and elongation of SIRD samples were increased by 12.9% and 35.3%, respectively, compared to a conventional liquid die casting sample.

  17. Microstructure And Mechanical Properties Of An Al-Zn-Mg-Cu Alloy Produced By Gravity Casting Process

    OpenAIRE

    2015-01-01

    High-strength aluminum alloy are widely used for structural components in aerospace, transportation and racing car applications. The objective of this study is to enhance the strength of the Al-Zn-Mg-Cu alloy used for gravity casting process. All alloys cast into stepped-form sand mold (Sand-mold Casting; SC) and Y-block shaped metal mold(Permanent mold Casting; PC) C and then two –step aged at 398-423 K after solution treated at 743 K for 36 ks. The tensile strength and total elongation of t...

  18. Impact of sea-level rise in a Mediteranean delta: The Ebro delta cast

    NARCIS (Netherlands)

    Sánchez-Arcilla, A.; Stive, M.D.F.; Jiménez, J.A.; García, M.A.

    1993-01-01

    In anticipation of a comprehensive, multidisciplinary study on the impact of climatic change on the Ebro Delta preliminary results are here presented of the response of the outer delta coast to present and future relative sea-level rise. Due to the absence of observations and predictions of regional

  19. Processing and mechanical properties of SiC particulate reinforced AZ91 composites fabricated by stir casting

    Institute of Scientific and Technical Information of China (English)

    WANG Xiao-jun; WU Kun; PENG De-lin; ZHANG Hai-feng; ZHENG Ming-yi; HUANG Wen-xian

    2006-01-01

    The influence of stirring parameters (stirring temperature, stirring speed and stirring time) on the particle distribution of 10%(volume fraction) SiC particulate reinforced AZ91 composites (SiCp/AZ91) was studied. It is found that it is necessary for 10 μm SiC particulate reinforced AZ91 composites to stir the molten composites in semi-solid condition with vortex formation, or else the cluster of the reinforcements would not be eliminated. Compared with the monolithic alloy, the SiCp/AZ91 composite has higher strength, especially for yield strength, but the elongation is reduced. For the as-cast composite, the particles often segregate within the grain boundary regions. Extrusion can effectively reduce the segregation of SiC particles and improve the mechanical properties of the composite. The extrusion-induced reduction in particle size varies with extrusion temperatures and extrusion ratios. The effect of extrusion-induced reduction in particle size on the mechanical properties of the composites is not always beneficial.

  20. DEVELOPMENTS IN THE FIELD OF STEEL AND CAST IRON

    Directory of Open Access Journals (Sweden)

    E. B. Ten

    2013-01-01

    Full Text Available The article describes the use of a number of promising casting technologies applied to produce the castings of steel and cast iron with special properties. Such as, technology of centrifugal casting of large-size workpieces made of steel, forecasting method composition of slag in the smelting of high-manganese steels, method of complex modifying chromium cast irons, analysis of properties of perspective high-alloy aluminium cast iron.

  1. Effect of Zr Addition on Glass-Forming Ability and Magnetic Properties of Fe-Nd-Al-B Alloys Prepared by Suction Casting

    Institute of Scientific and Technical Information of China (English)

    BAI Qin; XU Hui; TAN Xiao-Hua; MENG Tao

    2009-01-01

    The microstructure and magnetic behaviors of the Fe--Nd-AI-B alloys prepared by suction casting with zirconium addition are investigated. With the small amount of zirconium addition, the magnetic properties of the alloys change from hard magnetic property to soft magnetic property. The proper addition of Zr (6%) not only improves the glass forming ability, but also suppresses the crystallization. From the scanning electron microscopy of the [(Fe0.53Nd0.37Al0.10)0.96B0.04]94Zr6 alloy and the local average elemental compositions determined using energy dispersive spectroscopy analysis, the amorphous phase with a composition of Fe47Nd38Al12Zr3 in the alloy can be observed. The bulk amorphous Fe47Nd38Al12Zr3 alloy is prepared by suction casting exhibiting good glassforming ability and soft magnetic behavior.

  2. Microstructure Evolution and Mechanical Properties of Rheo-Squeeze Cast Mg-9Al-1Zn Alloy by Experiments and Thermodynamic Calculation

    Science.gov (United States)

    Guo, Hong-Min; Zhang, Shu-Guo; Yang, Xiang-Jie; Liu, Xu-Bo; Jin, Hua-Lan

    2015-05-01

    Microstructure evolution and mechanical properties of Mg-9Al-1Zn alloy produced by rheo-squeeze casting (R-SQC) were investigated. It was revealed that R-SQC has produced high integrity castings with fine and uniform microstructure, diminished defects, and improved mechanical properties. The solid content in semi-solid slurry determined the grain size of α-Mg phase, the volume content, and distribution of β-Mg17Al12 phase, and predominantly controlled the mechanical properties. A two-stage thermodynamic calculation procedure to analyze R-SQC has been developed, and the solidification path and phase formation of Mg-9Al-1Zn alloy in R-SQC were discussed deeply.

  3. Study on the Mechanical Properties of Cast 6063 Al Alloy Using a Mixture of Aluminum Dross and Green Sand as Mold

    Science.gov (United States)

    Adeosun, S. O.; Sekunowo, O. I.; Balogun, S. A.; Obembe, O. O.

    2012-08-01

    The mechanical characteristics of 6063 aluminum alloy cast in a mixture of aluminum dross and silica sand as mold have been examined. The amount of dross in the green silica sand was varied in the range of 0-80% with bentonite as binder. In all, 40 samples were cast, and 8 of these were left in the as-cast condition for control while 32 were first homogenized at 470°C for 6 h and then rolled in a two-high mill at ambient temperature to 10% reduction in one pass. The rolled samples were solution heat treated at 515°C for 8 h followed by normalizing, annealing, and quench tempering, respectively. The samples were then simulated and tensile behavior coupled with the evaluation of microhardness and microstructures developed. The results obtained demonstrate significant improvement in mechanical properties from 50% to 80% dross in the mold. Tensile strength increased to 177 MPa and 15% elongation compared with conventional 6063-T5 aluminum alloy with 145 MPa tensile strength and 8% elongation. The improvement in mechanical properties by the quench-tempered samples can be attributed to the inducement of fine and coherent Mg2Si crystals within the matrix. Furthermore, the overall analysis of the proportion of dross to the size of cast show that about 64% of dross generated can be utilized as mold material.

  4. Addition of Oils to Polylactide Casting Solutions as a Tool to Tune Film Morphology and Mechanical Properties

    NARCIS (Netherlands)

    Sawalha, H.I.M.; Schroën, C.G.P.H.; Boom, R.M.

    2010-01-01

    Poly(L-lactide) (PLLA) films exhibit toughening by the addition of oils to the polymer casting. This was investigated by casting films from solution and evaporation in air; the investigated oils were linear alkanes, cyclic alkanes, and two terpenes (limonene and eugenol). The addition of the oils gr

  5. Dependence Of The Structure And Magnetic Properties Of Cast Plate-Shaped Nd60Fe30Al10 Samples On Their Thickness

    Directory of Open Access Journals (Sweden)

    Michalski B.

    2015-09-01

    Full Text Available The hard magnetic Nd-Fe-Al alloys are inferior to Nd-Fe-B magnets as far as the magnetic properties are concerned, but their great advantage is that they need no additional annealing to achieve good magnetic properties. These properties depend on the cooling rate from the melting state, and on the thickness of the sample - the best values are achieved at the quenching rates at which the samples have a thickness of 0.3-2 mm. The present study is concerned with the correlation between the magnetic properties of the plate-shaped Nd60Fe30Al10 samples and their size - thickness. Two casting ways: with the melt stream perpendicular direction and parallel to the surface of the plates were used. The plates were produced by pressure casting and suction casting. The studies have shown that the cooling rates depends on local propagation on liquid metal in the mold resulting in heterogeneity of structure and properties.

  6. LED环氧灌封工艺对其可靠性的影响%Impact of LED Epoxy Casting Process on Its Reliability

    Institute of Scientific and Technical Information of China (English)

    郑智斌

    2012-01-01

    根据实际工作中分析发光二极管(LED)产品失效问题所获得的经验,探讨环氧树脂灌封工艺对LED可靠性的影响.采用理论结合试验验证的方法,从环氧树脂材料性能、固化工艺条件和改善树脂材料性能等方面,总结出环氧树脂灌封工艺影响LED可靠性的具体因素.环氧树脂材料的性能参数如玻璃化转变温度、热膨胀系数和弹性模量等会影响LED耐焊接热和光衰的能力;降低固化工艺条件会减少LED内应力,防止芯片隐裂;在环氧树脂中添加偶联剂可以提高LED产品气密性,防止水汽渗透,提高LED可靠性.最后建议应当根据不同LED的可靠性要求,选择合适的环氧树脂和固化工艺条件.%According to the experience gained from the analysis of light emitting diode (LED) product failure problems in practical working, the impact of epoxy casting process on LED reliability was discussed. With the method of combining theory and experiment, the specific factors of epoxy resin casting process to influence LED reliability were summarized from aspects including material properties of epoxy resin, curing process condition and resin material performance improvement. The epoxy resin material performance parameters such as glass transition temperature, thermal expansion coefficient and elastic modulus will affect LED resistance to soldering heat and light decay; lowering LED curing process conditions will reduce LED inner stress and prevent the chip from hidden cracking; adding coupling agents in epoxy resin can improve the air tightness of LED products, prevent moisture penetration, and improve LED reliability. Finally, the suggestion of choosing appropriate epoxy resin and curing process conditions according to different LED reliability requirements was brought up.

  7. Caste System

    OpenAIRE

    Hoff, Karla

    2016-01-01

    In standard economics, individuals are rational actors and economic forces undermine institutions that impose large inefficiencies. The persistence of the caste system is evidence of the need for psychologically more realistic models of decision-making in economics. The caste system divides South Asian society into hereditary groups whose lowest ranks are represented as innately polluted. ...

  8. Materials for Advanced Ultrasupercritical Steam Turbines Task 4: Cast Superalloy Development

    Energy Technology Data Exchange (ETDEWEB)

    Thangirala, Mani

    2015-09-30

    The Steam Turbine critical stationary structural components are high integrity Large Shell and Valve Casing heavy section Castings, containing high temperature steam under high pressures. Hence to support the development of advanced materials technology for use in an AUSC steam turbine capable of operating with steam conditions of 760°C (1400°F) and 35 Mpa (5000 psia), Casting alloy selection and evaluation of mechanical, metallurgical properties and castability with robust manufacturing methods are mandated. Alloy down select from Phase 1 based on producability criteria and creep rupture properties tested by NETL-Albany and ORNL directed the consortium to investigate cast properties of Haynes 282 and Haynes 263. The goals of Task 4 in Phase 2 are to understand a broader range of mechanical properties, the impact of manufacturing variables on those properties. Scale up the size of heats to production levels to facilitate the understanding of the impact of heat and component weight, on metallurgical and mechanical behavior. GE Power & Water Materials and Processes Engineering for the Phase 2, Task 4.0 Castings work, systematically designed and executed casting material property evaluation, multiple test programs. Starting from 15 lbs. cylinder castings to world’s first 17,000 lbs. poured weight, heavy section large steam turbine partial valve Haynes 282 super alloy casting. This has demonstrated scalability of the material for steam Turbine applications. Activities under Task 4.0, Investigated and characterized various mechanical properties of Cast Haynes 282 and Cast Nimonic 263. The development stages involved were: 1) Small Cast Evaluation: 4 inch diam. Haynes 282 and Nimonic 263 Cylinders. This provided effects of liquidus super heat range and first baseline mechanical data on cast versions of conventional vacuum re-melted and forged Ni based super alloys. 2) Step block castings of 300 lbs. and 600 lbs. Haynes 282 from 2 foundry heats were evaluated which

  9. Melting and casting of FeAl-based cast alloy

    Energy Technology Data Exchange (ETDEWEB)

    Sikka, V.K. [Oak Ridge National Lab., TN (United States); Wilkening, D. [Columbia Falls Aluminum Co., Columbia Falls, MT (United States); Liebetrau, J.; Mackey, B. [AFFCO, L.L.C., Anaconda, MT (United States)

    1998-11-01

    The FeAl-based intermetallic alloys are of great interest because of their low density, low raw material cost, and excellent resistance to high-temperature oxidation, sulfidation, carburization, and molten salts. The applications based on these unique properties of FeAl require methods to melt and cast these alloys into complex-shaped castings and centrifugal cast tubes. This paper addresses the melting-related issues and the effect of chemistry on the microstructure and hardness of castings. It is concluded that the use of the Exo-Melt{trademark} process for melting and the proper selection of the aluminum melt stock can result in porosity-free castings. The FeAl alloys can be melted and cast from the virgin and revert stock. A large variation in carbon content of the alloys is possible before the precipitation of graphite flakes occurs. Titanium is a very potent addition to refine the grain size of castings. A range of complex sand castings and two different sizes of centrifugal cast tubes of the alloy have already been cast.

  10. Melting and casting of FeAl-based cast alloy

    Energy Technology Data Exchange (ETDEWEB)

    Sikka, V.K. [Oak Ridge National Lab., TN (United States). Metals and Ceramics Div.; Wilkening, D. [Columbia Falls Aluminum Co., 2000 Aluminum Dr., Columbia Falls, MT 59912 (United States); Liebetrau, J.; Mackey, B. [AFFCO, L.L.C., P.O. Box 1071, Anaconda, MT 59711 (United States)

    1998-12-31

    The FeAl-based intermetallic alloys are of great interest because of their low density, low raw material cost, and excellent resistance to high-temperature oxidation, sulfidation, carburization, and molten salts. The applications based on these unique properties of FeAl require methods to melt and cast these alloys into complex-shaped castings and centrifugal cast tubes. This paper addresses the melting-related issues and the effect of chemistry on the microstructure and hardness of castings. It is concluded that the use of the Exo-Melt{sup TM} process for melting and the proper selection of the aluminum melt stock can result in porosity-free castings. The FeAl alloys can be melted and cast from the virgin and revert stock. A large variation in carbon content of the alloys is possible before the precipitation of graphite flakes occurs. Titanium is a very potent addition to refine the grain size of castings. A range of complex sand castings and two different sizes of centrifugal cast tubes of the alloy have already been cast. (orig.) 18 refs.

  11. Inlfuence of carbon content on microstructure and mechanical properties of Mn13Cr2 and Mn18Cr2 cast steels

    Institute of Scientific and Technical Information of China (English)

    Lu Dingshan; Liu Zhongyi; Li Wei

    2014-01-01

    In this paper, a comparison study was carried out to investigate the inlfuence of carbon content on the microstructure, hardness, and impact toughness of water-quenched Mn13Cr2 and Mn18Cr2 cast steels. The study results indicate that both steels' water-quenched microstructures are composed of austenite and a smal amount of carbide. The study also found that, when the carbon contents are the same, there is less carbide in Mn18Cr2 steel than in Mn13Cr2 steel. Therefore, the hardness of Mn18Cr2 steel is lower than that of Mn13Cr2 steel but the impact toughness of Mn18Cr2 steel is higher than that of Mn13Cr2 steel. With increasing the carbon content, the hardness increases and the impact toughness decreases in these two kinds of steels, and the impact toughness of Mn18Cr2 steel substantialy exceeds that of Mn13Cr2 steel. Therefore, the water-quenched Mn18Cr2 steel with high carbon content could be applied to relatively high impact abrasive working conditions, while the as-cast Mn18Cr2 steel could be only used under working conditions of relatively low impact abrasive load due to lower impact toughness.

  12. ZL105合金挤压铸造工艺研究%Mechanical Properties of Squeezing Casting ZL105 Alloy

    Institute of Scientific and Technical Information of China (English)

    张会

    2012-01-01

    ZL105 alloy was prepared with ZL102 alloy, pure aluminum, copper plate and Mg ingot. Effects of processing parameters on the mechanical properties and microstructure of squeezing castings were investigated by orthogonal testing. The results show that the influencing factors on strength of the squeezing castings are as follows: pouring temperature, holding time, pressure, and dominant factors on plasticity is pouring temperature. The dominant factor influencing mechanical properties and microstructure of the squeezing castings is pouring temperature. Tensile strength of the permanent mold castings after heat treatment reaches 225. 0 MPa, while tensile strength of squeezing casting after heat treatment reaches 249. 8 MPa, improved by 11. 0%.%以ZL102、纯铝、铜板、镁块为原材料熔配成ZL105合金.采用正交试验方法研究ZL105合金挤压铸造工艺参数对成型件力学性能和显微组织的影响.结果表明,挤压铸造工艺参数对合金强度影响的程度大小依次为:合金浇注温度、保压时间、比压;对塑性影响最大的是合金浇注温度.合金浇注温度是对铸件的性能和显微组织影响最为显著的因素.金属型铸件热处理后的抗拉强度为225.0 MPa,挤压铸件热处理后的抗拉强度平均达到249.8 MPa,抗拉强度较金属型增加了11.0%.

  13. Structural and mechanical properties of 7075 alloy strips fabricated by roll-casting in a static magnetic field

    Science.gov (United States)

    Su, Xin; Xu, Guang-ming; Jiang, Jiu-wen

    2014-07-01

    The influences of a 0.2 T static magnetic field on the microstructure of 7075 aluminum alloys sheets produced with a twin-roll continuous caster at 675°C were investigated in this paper. Under a uniform magnetic field, the primary dendrites were refined and tended to be equiaxed. The microstructure consisted of an intermediate case between dendritic and equiaxed grains. Moreover, the use of an external static field in the twin-roll casting process can reduce heat discharge, resulting in a decrease in undercooling, and may also account for the abatement of segregation bands. In addition, the static magnetic field effectively improved the solute mixing capacity, and the added atoms more easily diffused from precipitates to the α-Al matrix, which resulted in an increase in the mechanical properties of the rolled sheets. Specimens prepared both in the presence of a static magnetic field and in the absence of a static magnetic field exhibited brittle-fracture characteristics.

  14. Structural and mechanical properties of 7075 alloy strips fabricated by roll-casting in a static magnetic field

    Institute of Scientific and Technical Information of China (English)

    Xin Su; Guang-ming Xu; Jiu-wen Jiang

    2014-01-01

    The influences of a 0.2 T static magnetic field on the microstructure of 7075 aluminum alloys sheets produced with a twin-roll continuous caster at 675°C were investigated in this paper. Under a uniform magnetic field, the primary dendrites were refined and tended to be equiaxed. The microstructure consisted of an intermediate case between dendritic and equiaxed grains. Moreover, the use of an external static field in the twin-roll casting process can reduce heat discharge, resulting in a decrease in undercooling, and may also account for the abatement of segregation bands. In addition, the static magnetic field effectively improved the solute mixing capacity, and the added atoms more easily diffused from precipitates to theα-Al matrix, which resulted in an increase in the mechanical properties of the rolled sheets. Specimens prepared both in the presence of a static magnetic field and in the absence of a static magnetic field exhibited brittle-fracture characteristics.

  15. Preparation and properties of multi-wall carbon nanotube/SiC composites by aqueous tape casting

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    MWCNTS/SiC composites were fabricated by aqueous tape casting. High solid content (50 vol%) SiC slurries with sintering additives and multi-wall carbon nanotubes (MWCNTs) as reinforcements were prepared using Tetramethylammonium hydroxide as the dispersant. The stability of MWCNTs/SiC slur-ries was studied and characterized in terms of zeta potential and rheology measurements. The relative density of the composite was about 98% after hot-pressing at 1850℃ (at 25 MPa in Ar for 30 min). The hardness of the composites decreased with the increase in MWCNTs content. The flexural strength and the fracture toughness were 742.17 MPa and 4.63 MPa·m1/2, respectively when the MWCNTs content was 0.25 wt%. Further increase in MWCNTs content to 0.50 wt% did not lead to the increase in mechanical properties. Most of MWCNTs were found to be located at SiC grain boundaries and the pull out of the MWCNTs was observed.

  16. Effect of Rolling Route on Microstructure and Tensile Properties of Twin-Roll Casting AZ31 Mg Alloy Sheets

    Directory of Open Access Journals (Sweden)

    Dan Luo

    2016-06-01

    Full Text Available Twin-roll casting AZ31 Mg alloy sheets have been fabricated by normal unidirectional-rolling, head-to-tail rolling, and clock-rolling, respectively. It has been demonstrated that head-to-tail rolling is the most effective to refine the microstructure and weaken the basal texture among the three rolling routes. Excellent integrated tensile properties can be obtained by the head-to-tail rolling. The yield strength, ultimate tensile strength, and plastic elongation are 196 MPa, 301 MPa, and 28.9%, respectively. The strength can benefit from the fine grains (average value of 4.0 μm of the AZ31 alloy processed by the head-to-tail rolling route, while the excellent plastic elongation is achieved owing to the weakened basal texture besides the fine grains. Results obtained here can be used as a basis for further study of some simple rolling methods, which is critical to the development of Mg alloys with high strength and plasticity.

  17. Statistical Assessment of the Impact of Elevated Contents of Cu and Ni on the Properties of Austempered Ductile Iron

    Directory of Open Access Journals (Sweden)

    Nawrocki P.

    2016-12-01

    Full Text Available The article presents a statistical analysis of data collected from the observation of the production of austempered ductile iron. The impact assessment of the chemical composition, i.e. high contents of Cu and Ni on the properties of ductile iron isothermal tempered is critical to find the right chemical composition of austempered ductile iron. Based on the analyses range of the percentage of Cu and Ni which were selected in the cast iron to obtain material with high strength properties.

  18. Development of a Nickel-base Cast Superalloy with High Strength and Superior Creep Properties

    Institute of Scientific and Technical Information of China (English)

    Jieshan HOU; Jianting GUO; Lanzhang ZHOU; Zhijun LI

    2005-01-01

    Derived from Russian alloy CHS88U, six experimental Ni-base alloys named as A to F in the Ni-Cr-Co-W-Ti-Al-Hf system are designed, evaluated and processed. One of these alloys, F, shows excellent high temperature tensile strength and ductility with superior creep rupture properties. As predicted by using modeling tools such as PHACOM and NEW PHACOMP, there is hardly the tendency for formation of topologically close-packed phase (TCP) phase in alloy F. Furthermore, through microstructural observation, it is also found that no TCP phase is formed in alloy F after long-time exposure at high temperature. So alloy F has well balance of phase stability and mechanical properties in view of application for gas turbines. It is proved that d-electron approach can be applied for design and development of nickel-base superalloys for gas turbine application.

  19. Electrochemical Properties of Strip Casting LPCNi3.55Co0.75Mn0.4Al0.3 Hydrogen Storage Alloys

    Institute of Scientific and Technical Information of China (English)

    吴朝玲; 陈云贵; 李锋; 唐定骧; 李梦; 涂铭旌

    2002-01-01

    LPCNi3.55Co0.75Mn0.4Al0.3 hydrogen storage alloy was investigated, and the effects of thickness of its strip casting ingots(as-cast) on the electrochemical performances were discussed. It was found that the 0.2 C discharge capacity increased with the increase of the thickness (from 1 mm to 10 mm) of the ingots, mainly due to the enlargement of the unit cell volume; Among the thickness of the ingots in our study, 10 mm sample showed a better activation property; LPCNi3.55Co0.75Mn0.4Al0.3 alloy with 10mm showed higher comprehensive properties than those with other thickness under 1C rate.

  20. Microstructure and mechanical properties of in situ casting TiC/Ti6Al4V composites through adding multi-walled carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Ya, Bin; Zhou, Bingwen; Yang, Hongshuo; Huang, Bingkun; Jia, Fei; Zhang, Xingguo, E-mail: zxgwj@dlut.edu.cn

    2015-07-15

    Highlights: • Adding MWCNTs in situ casting fabricating TiC/Ti6Al4V composites is first reported. • The solidification process of in situ casting TiC/Ti6Al4V composites is discussed. • Microstructure shows remarkable correlations with adding MWCNTS. • Strength and plasticity show remarkable correlations with adding MWCNTs. - Abstract: In this study, multi-walled carbon nanotubes (MWCNTs) were added as carbon sources to fabricate in situ casting TiC/Ti6Al4V (TC4) composites. The effects of MWCNTs on the microstructure and mechanical properties are studied. The composites are analyzed by X-ray diffraction, field-emission scanning electron microscope and electron probe microanalysis. The fracture behavior of TiC/TC4 composites are also studied. Smaller size of TiC particles and grain compared with TC4-graphite composites can be observed. The tensile strength of TC4-MWCNTs composites is about 1110.1 MPa, which is higher than that of TC4-graphite composites, about 1003.6 MPa. Fracture behavior also was changed by adding MWCNTs in situ casting TiC/TC4 composites.

  1. Study of the effect of solidification on graphite flakes microstructure and mechanical properties of an ASTM a-48 gray cast iron using steel molds

    OpenAIRE

    Ganwarich Pluphrach

    2010-01-01

    The analysis of heat conduction is a widely used technique for control of metallurgical process and solidified eutecticalloy investigation. The objectives of this research are studies about the effect of solidification on graphite flakes microstructureand mechanical properties of an ASTM A-48 gray cast iron using SKD 11 tool steel, S45C medium carbon steel andSS400 hot-rolled steel molds. These three steel molds are important for heat conduction and different from other works. Thisanalysis in...

  2. The microstructure and properties of as-cast Sn-Zn-Bi solder alloys

    Directory of Open Access Journals (Sweden)

    Mladenović Srba A.

    2012-01-01

    Full Text Available Research on the lead-free solders has attracted wide attention, mostly as the result of the implementation of the Directive on the Restriction of the Use of Hazardous Substances in Electrical and Electronic Equipment. The Sn-Zn solder alloys have been considered to be one of the most attractive lead-free solders due to its ability to easily replace Sn-Pb eutectic alloy without increasing the soldering temperature. Furthermore, the mechanical properties are comparable or even superior to those of Sn-Pb solder. However, other problems still persist. The solution to overcoming these drawbacks is to add a small amount of alloying elements (Bi, Ag, Cr, Cu, and Sb to the Sn-Zn alloys. Microstructure, tensile strength, and hardness of the selected Sn-Zn-Bi ternary alloys have been investigated in this study. The SEM-EDS was used for the identification of co-existing phases in the samples. The specimens’ microstructures are composed of three phases: Sn-rich solid solution as the matrix, Bi-phase and Zn-rich phase. The Bi precipitates are formed around the Sn-dendrit grains as well as around the Zn-rich phase. The amount of Bi segregation increases with the increase of Bi content. The Sn-Zn-Bi alloys exhibit the high tensile strength and hardness, but the values of these mechanical properties decrease with the increase of Bi content, as well as the reduction of Zn content. The results presented in this paper may offer further knowledge of the effects various parameters have on the properties of lead-free Sn-Zn-Bi solders.

  3. Fracture Mechanisms in Steel Castings

    Directory of Open Access Journals (Sweden)

    Z. Stradomski

    2013-07-01

    Full Text Available The investigations were inspired with the problem of cracking of steel castings during the production process. A single mechanism of decohesion - the intergranular one - occurs in the case of hot cracking, while a variety of structural factors is decisive for hot cracking initiation, depending on chemical composition of the cast steel. The low-carbon and low-alloyed steel castings crack due to the presence of the type II sulphides, the cause of cracking of the high-carbon tool cast steels is the net of secondary cementite and/or ledeburite precipitated along the boundaries of solidified grains. Also the brittle phosphor and carbide eutectics precipitated in the final stage solidification are responsible for cracking of castings made of Hadfield steel. The examination of mechanical properties at 1050°C revealed low or very low strength of high-carbon cast steels.

  4. Effects of Third Constituent on As-cast Microstructures and Mechanical Properties of Mg-Sn Alloy

    Directory of Open Access Journals (Sweden)

    HUANG Zheng-hua

    2016-06-01

    Full Text Available As-cast microstructures and phase compositions of Mg-3.52Sn-xM and Mg-6.54Sn-xM (M=Al, Zn, Nd, Gd alloys were investigated by optical microscope, scanning electron microscope and X-ray diffraction. Meanwhile, the tensile mechanical properties were tested. The results show that the coarse dendrite is refined slightly and few block Mg2Sn phase still exists when 0.91% (mass fraction, the same below Al and 1.03%Zn are added into Mg-3.52Sn alloy, respectively. When 0.92%Nd and 1.10%Gd are added respectively, the dendrite weakens obviously and many small block or fine short rod-shaped compounds Mg-Sn-Nd and Mg-Sn-Gd can be observed. When 0.93%Al and 1.08%Zn are added into Mg-6.54Sn respectively, the dendrite is refined obviously and Mg2Sn phase tending to precipitate in the state of continuous net begins to break slightly. When 0.86%Nd and 0.74%Gd are added respectively, the dendrite weakens significantly and Mg2Sn phase has already broken into small block completely or significantly. Meanwhile, many small block or fine short rod-shaped compounds Mg-Sn-Nd and Mg-Sn-Gd can also be observed. The respective addition of about 1%Al and Zn into the Mg-3.52Sn and Mg-6.54Sn binary alloys respectively can enhance the tensile mechanical properties namely the ambient and elevated temperatures effectively, while the respective addition of about 1%Nd and Gd cannot enhance them effectively, especially for the addition of Nd.

  5. Structure and mechanical properties of as-cast (ZrTi){sub 100−x}B{sub x} alloys

    Energy Technology Data Exchange (ETDEWEB)

    Xia, C.Q.; Jiang, X.J.; Wang, X.Y.; Zhou, Y.K.; Feng, Z.H. [State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004 (China); Tan, C.L. [Beijing Institute of Spacecraft System Engineering, Beijing 100094 (China); Ma, M.Z. [State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004 (China); Liu, R.P., E-mail: riping@ysu.edu.cn [State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004 (China)

    2015-07-15

    Highlights: • Trace boron additions result in significant grain refinement. • Large numbers of stacking faults are observed in ZrB{sub 2} and TiB intermetallics. • The tensile strength is enhanced by increasing the amount of B. • Intermetallics microcracking causes the failure of the alloys. - Abstract: The microstructure, mechanical properties, and fracture characteristics of (Zr{sub 50}Ti{sub 50}){sub 100−x}B{sub x} alloys (x = 0, 0.5, 1, 2 at.%) obtained by casting were investigated. Trace additions of boron (B) to the Zr{sub 50}Ti{sub 50} alloys induced significant microstructural changes. Changes included the promotion of dendritic growth and refinement in prior-β grain and α′-lath size. Large numbers of stacking faults were also observed in ZrB{sub 2} and TiB intermetallics. The location of B atoms and the lattice mismatch energy between intermetallics and matrix were responsible for the stacking faults. (ZrTi)B alloys demonstrated higher tensile strength than matrix material. Both the intermetallics with high strength and modulus and the grain refinement played important roles in improving the mechanical properties of alloys. This result could be explained in terms of a shear-lag model based on the load transfer concept and Hall–Petch mechanism. The elongation-to-failure of (ZrTi)B alloys decreased with increased B concentration. The reduction in elongation-to-failure of (ZrTi)B alloys could be attributed to the presence of ZrB{sub 2} and TiB intermetallics and refinement of α′-laths.

  6. Structure and Mechanical Properties of Al-Li Alloys as Cast

    Directory of Open Access Journals (Sweden)

    J. Augustyn-Pieniążek

    2013-04-01

    Full Text Available The high mechanical properties of the Al-Li-X alloys contribute to their increasingly broad application in aeronautics, as an alternative for the aluminium alloys, which have been used so far. The aluminium-lithium alloys have a lower specific gravity, a higher nucleation and crack spread resistance, a higher Young’s module and they characterize in a high crack resistance at lower temperatures. The aim of the research planned in this work was to design an aluminium alloy with a content of lithium and other alloy elements. The research included the creation of a laboratorial melt, the microstructure analysis with the use of light microscopy, the application of X-ray methods to identify the phases existing in the alloy, and the microhardness test.

  7. Influence of compound deoxidation of steel with Al, Zr, rare earth metals, and Ti on properties of heavy castings

    Directory of Open Access Journals (Sweden)

    J. Senberger

    2012-01-01

    Full Text Available Heavy steel castings deoxidized with aluminium are sometimes brittle intercrystalline failed during their service along primary grain boundaries what is initiated by aluminium nitrides and so called conchoidal fractures are formed. The tendency to forming the conchoidal fractures depends in particular on cooling rate (the casting modulus, aluminium and nitrogen contents in steel. During deoxidation, when manufacturing heavy castings, the elements with high affinity to nitrogen, zirconium or titanium, are added to steel that would decrease nitrogen activity by the bond on stable nitrides. The formation of stable nitrides should reduce the tendency of steel to the formation of conchoidal fractures. Deoxidation was thermodynamically analyzed at presence of the mentioned elements. For particular conditions a probable course of deoxidation was estimated at test castings. The deoxidation course was checked by microanalysis of deoxidation products (inclusions. For service and experimental castings the anticipated composition of inclusions was compared. It has been proved that in heavy castings with high aluminium contents in steel under studied conditions neither the addition of zirconium nor of titanium nor of rare earth metals will prevent the formation of conchoidal fractures.

  8. Developing technological process of obtaining giality casts

    Directory of Open Access Journals (Sweden)

    A. Issagulov

    2014-10-01

    Full Text Available The article considers the process of manufacturing castings using sand-resin forms and alloying furnace. Were the optimal technological parameters of manufacturing shell molds for the manufacture of castings of heating equipment. Using the same upon receipt of castings by casting in shell molds furnace alloying and deoxidation of the metal will provide consumers with quality products and have a positive impact on the economy in general engineering.

  9. Application of Integrated Database to the Casting Design

    Institute of Scientific and Technical Information of China (English)

    In-Sung Cho; Seung-Mok Yoo; Chae-Ho Lim; Jeong-Kil Choi

    2008-01-01

    Construction of integrated database including casting shapes with their casting design, technical knowledge, and thermophysical properties of the casting alloys were introduced in the present study. Recognition tech- nique for casting design by industrial computer tomography was used for the construction of shape database. Technical knowledge of the casting processes such as ferrous and non-ferrous alloys and their manufacturing process of the castings were accumulated and the search engine for the knowledge was developed. Database of thermophysical properties of the casting alloys were obtained via the experimental study, and the properties were used for .the in-house computer simulation of casting process. The databases were linked with intelligent casting expert system developed in center for e-design, KITECH. It is expected that the databases can help non casting experts to devise the casting and its process. Various examples of the application by using the databases were shown in the present study.

  10. The electrochemical properties of four dental casting suprastructure alloys coupled with titanium implants

    Directory of Open Access Journals (Sweden)

    Suleyman Hakan Tuna

    2009-10-01

    Full Text Available OBJECTIVES: As the choice of suprastructure alloy to be combined with titanium for the oral cavity is still a much debated issue, the aim of this study was to investigate the electrochemical interaction of the suprastructure/implant couples under the determined experiment conditions. MATERIAL AND METHODS: The potentiodynamic polarization curves and open-circuit potentials (OCP of four UCLA type suprastructures coupled with straight Swiss Plus implant fixtures were taken in Afnor type artificial saliva solution at 37°C. The concentration of ions leached into artificial saliva solutions was estimated with ICP-MS. SEM images of the margins of suprastructure/implant couples were obtained before and after the electrochemical tests. RESULTS: The OCP value of titanium became passive at the most negative potential. The lowest difference between the initial and constant OCP value was exhibited by the Au based suprastructure. Suprastructures made greater contributions to the potentiodynamic polarization curves of the implant/suprastructure couples. According to the ICP-MS results, Pd based and Au based couples dissolved less than Co-Ni based and Co-Cr based couples. CONCLUSIONS: Within the conditions this study, it may be concluded that the titanium implant forms a stable passive oxide layer in artificial saliva exposed to open air and does not affect the corrosion properties of the suprastructures. Pd based and Au based couples have been found to be more corrosion-resistant than base alloy couples.

  11. Extended Leach Testing of Simulated LAW Cast Stone Monoliths

    Energy Technology Data Exchange (ETDEWEB)

    Serne, R. Jeffrey [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Westsik, Joseph H. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Williams, Benjamin D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Jung, H. B. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Wang, Guohui [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-07-09

    This report describes the results from long-term laboratory leach tests performed at Pacific Northwest National Laboratory (PNNL) for Washington River Protection Solutions (WRPS) to evaluate the release of key constituents from monoliths of Cast Stone prepared with four simulated low-activity waste (LAW) liquid waste streams. Specific objectives of the Cast Stone long-term leach tests described in this report focused on four activities: 1. Extending the leaching times for selected ongoing EPA-1315 tests on monoliths made with LAW simulants beyond the conventional 63-day time period up to 609 days reported herein (with some tests continuing that will be documented later) in an effort to evaluate long-term leaching properties of Cast Stone to support future performance assessment activities. 2. Starting new EPA-1315 leach tests on archived Cast Stone monoliths made with four LAW simulants using two leachants (deionized water [DIW] and simulated Hanford Integrated Disposal Facility (IDF) Site vadose zone pore water [VZP]). 3. Evaluating the impacts of varying the iodide loading (starting iodide concentrations) in one LAW simulant (7.8 M Na Hanford Tank Waste Operations Simulator (HTWOS) Average) by manufacturing new Cast Stone monoliths and repeating the EPA-1315 leach tests using DIW and the VZP leachants. 4. Evaluating the impacts of using a non-pertechnetate form of Tc that is present in some Hanford tanks. In this activity one LAW simulant (7.8 M Na HTWOS Average) was spiked with a Tc(I)-tricarbonyl gluconate species and then solidified into Cast Stone monoliths. Cured monoliths were leached using the EPA-1315 leach protocol with DIW and VZP. The leach results for the Tc-Gluconate Cast Stone monoliths were compared to Cast Stone monoliths pertechnetate.

  12. Criterion for selection the optimal physical and chemical properties of cobalt aluminate powder used in investment casting process

    Directory of Open Access Journals (Sweden)

    M. Zielińska

    2009-07-01

    Full Text Available The aim of this work was to determine physical and chemical properties of cobalt aluminate (CoAl2O4 modifiers produced by different companies and the influence of different types of modifiers on the grain size of high temperature creep resisting superalloys: Inconel 713C, René 77 and MAR-M 509.The first stage of the research work took over the investigations of physical and chemical properties of cobalt aluminate manufactured by three different companies: Remet, Mason Color and Permedia Lublin. There were determined the grain size distribution of cobalt aluminate powder, the average diameter and morphology of powder particles, phase composition, as well as sodium and cobalt content, pH value of water suspension and the bulk density. In the next step, the ceramic moulds were made with different kind of cobalt aluminate (Mason Color, Remet, Permedia Lublin and its concentration (0, 5% in the primary slurry. The samples of stepped shape were poured in the ceramic moulds prepared earlier. The average grain size of the γ phase was determined on the stepped samples.It was established that physical and chemical properties of cobalt aluminate modifier are different up to the manufacturer. For example the modifiers manufactured by Permedia; Mason Color and Remet companies have different the average diameter of particles- 68,050d; 49,6 i 36,7μm, and also cobalt content _CoC=32,53%; 39,43% i 34,79%mass, respectively. The grain size of γ matrix of superalloys depends on the kind of used inoculant. The best grain refinement of the matrix of superalloys: Inconel 713C, René 77 and MAR-M 509 was observed in the castings modified with the use of Mason Color modifier. On the grounds of literature data and obtained results it was established that the cobalt content of cobalt aluminate influences the intensity of nucleation process during the crystallization of superalloys: Inconel 713C, René 77 i MAR-M 509.

  13. Solidification and casting

    CERN Document Server

    Cantor, Brian

    2002-01-01

    INDUSTRIAL PERSPECTIVEDirect chillcasting of aluminium alloysContinuous casting of aluminium alloysContinuous casting of steelsCastings in the automotive industryCast aluminium-silicon piston alloysMODELLING AND SIMULATIONModelling direct chill castingMold filling simulation of die castingThe ten casting rulesGrain selection in single crystal superalloy castingsDefects in aluminium shape castingPattern formation during solidificationPeritectic solidificationSTRUCTURE AND DEFECTSHetergeneous nucleation in aluminium alloysCo

  14. Preparation and properties of gradient Al2O3-ZrO2 ceramic foam by centrifugal slip casting method

    Directory of Open Access Journals (Sweden)

    Li Qiang

    2012-11-01

    Full Text Available The aim of the present research is to provide a novel technique for preparing gradient Al2O3-ZrO2 ceramic foams. This technique used epispastic polystyrene spheres to array templates and centrifugal slip casting to obtain cell struts with gradient distribution of Al2O3 and ZrO2 particles and high packing density. Aqueous Al2O3-20vol.% ZrO2 slurries with 20vol.% solid contents were prepared and the dispersion and rheological characteristics of the slurries were investigated. The settling velocity and mass segregation of Al2O3 and ZrO2 particles at different centrifugal accelerations were calculated and studied. The drying behavior, macrostructure, microstructure, compressive property and resistance to thermal shock of the sintered products were also investigated. The results show that the difference of settling velocity of Al2O3 and ZrO2 particles increases and mass segregation becomes acute with an increase in centrifugal acceleration. The cell struts prepared at a centrifugal acceleration of 1,690 g have high sintered density (99.0% TD and continuous gradient distribution of Al2O3 and ZrO2 particles. When sintered at 1,550 oC for 2 h, the cell size of gradient Al2O3-ZrO2 foam is approximately uniform, about 1.1 mm. With the porosity of gradient Al2O3-ZrO2 ceramic foams increasing from 75.3% to 83.0%, the compressive strength decreases from 4.4 to 2.4 MPa, and the ceramic foams can resist 8-11 repeated thermal shock from 1,100 oC to room temperature.

  15. Microstructure and Mechanical Properties of Al-10Zn-4.5Mg-xCu Turbine Impeller Produced by Investment Casting

    Directory of Open Access Journals (Sweden)

    Muhammad Syahid

    2017-03-01

    Full Text Available Aluminium alloy can be applied for a turbine impeller of Organic Rankine Cycle power plant that operates at temperatures below 150 oC. Aluminum turbine impeller can enhance efficiency of turbine due to light weight material. Al alloys was used for impeller due to good mechanical properties. Turbine impeller commonly produced by machining but which is time-consuming and less efficient because of material removal. . It can be replace by Investment casting to produce impeller turbine due to their complex geometry and precision. This study identifies effect Cu content of Al-9Zn-4Mg-xCu on the microstructure and mechanical properties of turbine impeller produce by investment casting. The study also identifies casting defect of turbine impeller. The structures consisted of α-Al, MgZn2, CuMgAl2 and CuAl2. Higher Cu content is the higher hardness value due to CuAl2 phase. Visual examination showed that the turbine impeller was free of macro defects and misruns

  16. Role of heat treatment in the improvement of mechanical properties of a high-quality Al-11Si-1.5Cu-0.3Mg casting alloy

    Directory of Open Access Journals (Sweden)

    Tao Lu

    2015-03-01

    Full Text Available The purpose of this study is to prepare a high-quality Al-11Si-1.5Cu-0.3Mg casting alloy with a good combination of strength and ductility. The microstructures of as-cast alloy were tailored by employing combined additives of Al-3wt.%B refiner, Al-10wt.%Sr modifier and trace addition of La element. By using OM and SEM, the characteristics of the morphologies of eutectic Si particles and the fracture surfaces of the alloys after solution treatment and aging treatment were measured. The mechanical properties of the alloys after single-step or two-step solution treatment were investigated by tensile testing, and the quality of casting samples were evaluated by quality index, Q. The results indicate that the alloy with substantially modified microstructures displays an improvement in mechanical properties of 270 MPa in ultimate tensile strength and 6% in elongation. After an optimized two-step solution treatment of 490篊/4h + 505篊/4h, the ultimate tensile strength and elongation can reach 346 MPa and 10%, respectively. Under the aging condition, the elongation maintains a relative high value of 5% together with the strength of about 400 MPa, which is the outstanding combination of strength and ductility.

  17. Role of heat treatment in the improvement of mechanical properties of a high-quality Al-11Si- 1.5Cu-0.3Mg casting alloy

    Institute of Scientific and Technical Information of China (English)

    Yu Chen

    2015-01-01

    The purpose of this study is to prepare a high-quality Al-11Si-1.5Cu-0.3Mg casting al oy with a good combination of strength and ductility. The microstructures of as-cast al oy were tailored by employing combined additives of Al-3wt.%B reifner, Al-10wt.%Sr modiifer and trace addition of La element. By using OM and SEM, the characteristics of the morphologies of eutectic Si particles and the fracture surfaces of the al oys after solution treatment and aging treatment were measured. The mechanical properties of the al oys after single-step or two-step solution treatment were investigated by tensile testing, and the quality of casting samples were evaluated by quality index, Q. The results indicate that the al oy with substantial y modiifed microstructures displays an improvement in mechanical properties of 270 MPa in ultimate tensile strength and 6% in elongation. After an optimized two-step solution treatment of 490ºC/4h+505ºC/4h, the ultimate tensile strength and elongation can reach 346 MPa and 10%, respectively. Under the aging condition, the elongation maintains a relative high value of 5%together with the strength of about 400 MPa, which is the outstanding combination of strength and ductility.

  18. FEATURES OF STRUCTURE FORMATION AND CHANGES IN THE MECHANICAL PROPERTIES OF CAST Al-Mg-Si-Mn ALLOY WITH THE ADDITION OF (Ti+Zr

    Directory of Open Access Journals (Sweden)

    Oleksandr Trudonoshyn

    2015-08-01

    Full Text Available The as-cast and heat-treated structure of permanent mould castings of AlMg5Si2Mn alloys with different contents of Ti has been investigated by differential scanning calorimetry, hardness and microhardness measurements, tensile tests and fractography analyses, scanning electron microscopy, transmission electron microscopy, and energy dispersive X-ray analysis. We have established that α-Al dendrites can be nucleated on an Al-Ti substrate, and also that primary Mg2Si crystals can be nucleated on oxides, including oxides of Al and Ti compounds. The dependence of the change in mechanical properties on ageing time, and on the amount of Ti in the alloys, is shown.

  19. Tribology properties of composite layer of CrMoCu alloy cast iron by combined treatment of ion nitrocarburizing and sulphurizing

    Institute of Scientific and Technical Information of China (English)

    MA Shi-ning; HU Chun-hua; LI Xin; QIU Ji

    2004-01-01

    Composite layer with nitrocarbonide and sulfide was made on the surface of CrMoCu alloy cast iron by combined treatment of ion nitrocarburizing and sulphurizing. The composite layer is composed of sulfide layer, nitrocarbonide hypo-surface layer and its diffusing layer, the size of sulfide globular grains distributing equably on the surface is in nano-micron-scale, and the phase structure of the composite layer is composed of FeS, FeS1-x, Fe2C and Fe3N. Under oil lubrication, sulphurized surface shows good scuffing-resistance only under low velocity, and nitrocarburized and sulphurized surface greatly improves the scuffing-resistance and wear-resistance of CrMoCu alloy cast iron, its integrated friction and wear properties are better than those of the plain and sulphurized surfaces under all the velocities.

  20. Grey water impact on soil physical properties

    Directory of Open Access Journals (Sweden)

    Miguel L. Murcia-Sarmiento

    2014-01-01

    Full Text Available Due to the increasing demand for food produced by the increase in population, water as an indispensable element in the growth cycle of plants every day becomes a fundamental aspect of production. The demand for the use of this resource is necessary to search for alternatives that should be evaluated to avoid potential negative impacts. In this paper, the changes in some physical properties of soil irrigated with synthetic gray water were evaluated. The experimental design involved: one factor: home water and two treatments; without treated water (T1 and treated water (T2. The variables to consider in the soil were: electrical conductivity (EC, exchangeable sodium percentage (ESP, average weighted diameter (MWD and soil moisture retention (RHS. The water used in drip irrigation high frequency was monitored by tensiometer for producing a bean crop (Phaseolous vulgaris L. As filtration system used was employed a unit composed of a sand filter (FLA and a subsurface flow wetland artificial (HFSS. The treatments showed significant differences in the PSI and the RHS. The FLA+HFSS system is an alternative to the gray water treatment due to increased sodium retention.

  1. Properties of pre-cast terrazzo tiles and recommended specifications Propriedades de telhas de terrazzo pré-moldadas e especificações recomendadas

    Directory of Open Access Journals (Sweden)

    G. Karam

    2009-03-01

    Full Text Available A targeted experimental program was carried out to establish basic reference physical and mechanical properties of commercially available pre-cast marble chip terrazzo tiles and to investigate the effects of varying manufacturing process parameters on those properties. The transverse strength, density, water absorption, and abrasion resistance were measured as a function of casting pressure and residence time in the casting mold for a standard mix design. A simple surface abrasion index test was developed and applied comparing pre-cast terrazzo tiles with reference natural tiling stones. Recommendations for improving existing specifications and developing quality control measures are presented.Foi feito um programa experimental direcionado para estabelecer propriedades físicas e mecânicas como referências básicas de telhas de terrazzo de peças de mármore pré-moldadas disponíveis comercialmente e para investigar os efeitos de vários parâmetros de processo de fabricação nessas propriedades. A resistência transversal, a densidade, a absorção de água e a resistência ao desgaste foram medidas em função da pressão de moldagem e do tempo de residência do molde de um projeto de mistura padrão. Um teste simples de índice de desgaste de superfície foi desenvolvido e aplicado na comparação de telhas de terrazzo pré-moldadas com pedras de telhas naturais de referência. As recomendações para a melhoria das especificações existentes e o desenvolvimento de medidas para controle de qualidade são apresentadas.

  2. Influence of casting size and graphite nodule refinement on fracture toughness of austempered ductile iron

    Energy Technology Data Exchange (ETDEWEB)

    Lee, S.C.; Hsu, C.H.; Chang, C.C.; Feng, H.P. [Tatung Inst. of Tech., Raipei (Taiwan, Province of China). Dept. of Materials Engineering

    1998-10-01

    Casting size affects the solidification cooling rate and microstructure of casting materials. Graphite nodules existing in the structure of ductile iron are an inherent and inert second phase that cannot be modified in subsequent heat-treatment processing. The matrix and the fineness of the second phase undoubtedly have some impact on the fracture toughness of the as-cast material, as does the subsequent heat treatment, as it alters the microstructure. This research applied austempering heat treatment to ductile iron of different section sizes and graphite nodule finenesses. The influence of these variables on the plane strain fracture toughness (K{sub IC}) of the castings so treated was compared to that of the as-cast state. Metallography, scanning electron microscopy (SEM), and X-ray diffraction analysis were performed to correlate the properties attained to the microstructural observation.

  3. The effects of novel surface treatments on the wear and fatigue properties of steel and chilled cast iron

    Science.gov (United States)

    Carroll, Jason William

    Contact fatigue driven wear is a principal design concern for gear and camshaft engineering of power systems. To better understand how to engineer contact fatigue resistant surfaces, the effects of electroless nickel and hydrogenated diamond-like-carbon (DLC) coatings on the fatigue life at 108 cycles of SAE 52100 steel were studied using ultrasonic fatigue methods. The addition of DLC and electroless nickel coatings to SAE 52100 bearing steel had no effect on the fatigue life. Different inclusion types were found to affect the stress intensity value beyond just the inclusion size, as theorized by Murakami. The difference in stress intensity values necessary to propagate a crack for Ti (C,N) and alumina inclusions was due to the higher driving force for crack extension at the Ti (C,N) inclusions and was attributed to differences in the shape of the inclusion: rhombohedral for the Ti (C,N) versus spherical for the oxides. A correction factor was added to the Murakami equation to account for inclusion type. The wear properties of DLC coated SAE 52100 and chilled cast iron were studied using pin-on-disk tribometry and very high cycle ultrasonic tribometry. A wear model that includes sliding thermal effects as well as thermodynamics consistent with the wear mechanism for DLCs was developed based on empirical results from ultrasonic wear testing to 108 cycles. The model fit both ultrasonic and classic tribometer data for wear of DLCs. Finally, the wear properties of laser hardened steels - SAE 8620, 4140, and 52100 - were studied at high contact pressures and low numbers of cycles. A design of experiments was conducted to understand how the laser processing parameters of power, speed, and beam size, as well as carbon content of the steel, affected surface hardness. A hardness maximum was found at approximately 0.7 wt% carbon most likely resulting from increased amounts of retained austenite. The ratcheting contact fatigue model of Kapoor was found to be useful in

  4. RESEARCH AND APPLICATION OF AS-CAST WEAR RESISTANCE HIGH CHROMIUM CAST IRON

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    The influence of alloy elements, such as boron and silicon, on the microstructure and properties of as-cast high chromium cast iron is studied. The results show that boron and silicon have a great effect on the mechanical properties and the wear resistance. Through proper addition of boron and silicon, the properties of as-cast high chromium cast iron can be improved effectively. Through analyzing the distribution of elements by scanning electron microscope, it has been shown that the addition of boron and silicon lowers the mass fraction of chromium saturated in as-cast austenite, and makes it unstable and liable to be transformed into martensite. The as-cast high chromium cast iron with proper content of boron and silicon is suitable for the manufacture of lining for asphalt concrete mixer and its wear resistance is 14 times that of lining made of low alloy white cast iron.

  5. The study of microstructure and mechanical properties of twin-roll cast AZ31 magnesium alloy after constrained groove pressing

    Science.gov (United States)

    Zimina, M.; Bohlen, J.; Letzig, D.; Kurz, G.; Cieslar, M.; Zník, J.

    2014-08-01

    Microstructure investigation and microhardness mapping were done on the material with ultra-fine grained structure prepared by constrained groove pressing of twin-roll cast AZ31 magnesium strips. The microstructure observations showed significant drop of the grain size from 200 gm to 20 gm after constrained groove pressing. Moreover, the heterogeneities in the microhardness along the cross-section observed in the as-cast strip were replaced by the bands of different microhardness in the constrained groove pressed material. It is shown that the constrained groove pressing technique is a good tool for the grain refinement of magnesium alloys.

  6. The influence of microstructure on the mechanical properties of metallurgical rolls made of G200CrMoNi4-3-3 cast steel

    Directory of Open Access Journals (Sweden)

    A. Brodziak

    2009-07-01

    Full Text Available The subject of the study is the high-carbon tool cast steel G200CrMoNi4-3-3 used for metallurgical rolls, especially in section rolling mills. The test material was derived from a roll damaged in production; therefore, the authors had the material in a raw state at their disposal, on which they were able to carry out additional heat treatment operations. The pearlitic matrix of casting steel G200CrMoNi4-3-3 allows machining to be done to modify the pass or to remove any defects, and the primary and secondary precipitates of carbides enhance the tribological properties. The authors have been for years involved in the optimization of the structure of this material by slight correction to its chemical composition and/or the modification of heat treatment. The presented principles of heat treatment modifications will lead to considerable economic and ecologic profits. It has also been demonstrated that raising slightly the contents of carbide-forming elements, which markedly increases the quantity of transformed ledeburite, results in an enhancement of tribological properties. The analysis of a dozen or so rolls exploited down to the dead roll diameter has shown that roll of cast steel with increased contents of carbon and carbide-forming elements exhibit better service properties, as characterized by the amount of feedstock rolled. Such a method of enhancing the service properties required the assessment of fracture toughness, which was verified using the linear-elastic methods of fracture mechanics.

  7. Comparison of High-Temperature Properties and Thermal Shock Resistance of Austempered Ductile Irons (ADI) with Those of Pearlitic Ductile Cast Irons

    Science.gov (United States)

    Ajabshiri, Mehrdad; Sharafi, Shahriar; Moeini, Alireza

    2012-01-01

    High-temperature strength and thermal shock resistance of austempered ductile iron (ADI) in high temperatures because of instability of ausferrite phase has been less interest. The aim of this study is to investigate the tensile properties of ADI and pearlitic ductile cast iron by using the short-time tensile test in high temperatures. Tensile test was conducted in temperatures of 298 K, 673 K, 873 K, and 1073 K (25 °C, 400 °C, 600 °C, and 800 °C). Thermal shock test also was conducted by using the molten lead bath at 1273 K (1000 °C). In this experiment, samples of pearlitic ductile cast iron and ADI were divided in two groups; that after immersing in the molten lead bath for 25 seconds, one group was cooled in the air and other one was quenched in the water. Results showed that strength and thermal shock resistance of ADI samples are higher than those of the pearlitic ductile cast iron.

  8. Effects of Iron-Rich Intermetallics and Grain Structure on Semisolid Tensile Properties of Al-Cu 206 Cast Alloys near Solidus Temperature

    Science.gov (United States)

    Bolouri, Amir; Liu, Kun; Chen, X.-Grant

    2016-12-01

    The effects of iron-rich intermetallics and grain size on the semisolid tensile properties of Al-Cu 206 cast alloys near the solidus were evaluated in relation to the mush microstructure. Analyses of the stress-displacement curves showed that the damage expanded faster in the mush structure dominated by plate-like β-Fe compared to the mush structure dominated by Chinese script-like α-Fe. While there was no evidence of void formation on the β-Fe intermetallics, they blocked the interdendritic liquid channels and thus hindered liquid flow and feeding during semisolid deformation. In contrast, the interdendritic liquid flows more freely within the mush structure containing α-Fe. The tensile properties of the alloy containing α-Fe are generally higher than those containing β-Fe over the crucial liquid fraction range of 0.6 to 2.8 pct, indicating that the latter alloy may be more susceptible to stress-related casting defects such as hot tearing. A comparison of the semisolid tensile properties of the alloy containing α-Fe with different grain sizes showed that the maximum stress and elongation of the alloy with finer grains were moderately higher for the liquid fractions of 2.2 to 3.6 pct. The application of semisolid tensile properties for the evaluation of the hot tearing susceptibility of experimental alloys is discussed.

  9. Impact of Thermal Aging on the Microstructure Evolution and Mechanical Properties of Lanthanum-Doped Tin-Silver-Copper Lead-Free Solders

    OpenAIRE

    Sadiq, Muhammad; Pesci, Raphaël; Cherkaoui, Mohammed

    2013-01-01

    The authors would like to thank Ste'phanie Blanc (Electrical Engineer at Schlumberger) for her useful contribution to the project, Claude Guyomard and Olivier Naegelen (Arts et Me'tiers ParisTech) for the die design and sample casting, respectively, and Jean-Marc Raulot for his enriching discussions.; International audience; An extensive study is made to analyze the impact of pure lanthanum on the microstructure and mechanical properties of Sn-Ag-Cu (SAC) alloys at high temperatures. Differen...

  10. Thick Co-based coating on cast iron by side laser cladding : Analysis of processing conditions and coating properties

    NARCIS (Netherlands)

    Ocelik, V.; de Oliveira, U.; de Boer, M.; de Hosson, J. Th. M.

    2007-01-01

    The objective of this work was to create Co-based coatings (compositionally close to Stellite 6) on compacted graphite and gray cast iron,substrates with a high power laser (2 kW continuous Nd:YAG) cladding process. The relationships between the relevant laser cladding parameters (i.e. laser beam sc

  11. Mechanical and Tribological Properties of HVOF-Sprayed (Cr3C2-NiCr+Ni) Composite Coating on Ductile Cast Iron

    Science.gov (United States)

    Ksiazek, Marzanna; Boron, Lukasz; Radecka, Marta; Richert, Maria; Tchorz, Adam

    2016-08-01

    The aim of the investigations was to compare the microstructure, mechanical, and wear properties of Cr3C2-NiCr+Ni and Cr3C2-NiCr coatings deposited by HVOF technique (the high-velocity oxygen fuel spray process) on ductile cast iron. The effect of nickel particles added to the chromium carbide coating on mechanical and wear behavior in the system of Cr 3 C 2 -NiCr+Ni/ductile cast iron was analyzed in order to improve the lifetime of coated materials. The structure with particular emphasis of characteristic of the interface in the system of composite coating (Cr 3 C 2 -NiCr+Ni)/ductile cast iron was studied using the optical, scanning, and transmission electron microscopes, as well as the analysis of chemical and phase composition in microareas. Experimental results show that HVOF-sprayed Cr3C2-NiCr+Ni composite coating exhibits low porosity, high hardness, dense structure with large, partially molten Ni particles and very fine Cr3C2 and Cr7C3 particles embedded in NiCr alloy matrix, coming to the size of nanocrystalline. The results were discussed in reference to examination of bending strength considering cracking and delamination in the system of composite coating (Cr 3 C 2 -NiCr+Ni)/ductile cast iron as well as hardness and wear resistance of the coating. The composite structure of the coating provides the relatively good plasticity of the coating, which in turn has a positive effect on the adhesion of coating to the substrate and cohesion of the composite coating (Cr3C2-NiCr+Ni) in wear conditions.

  12. Cradle-to-Gate Impact Assessment of a High-Pressure Die-Casting Safety-Relevant Automotive Component

    Science.gov (United States)

    Cecchel, Silvia; Cornacchia, Giovanna; Panvini, Andrea

    2016-09-01

    The mass of automotive components has a direct influence on several aspects of vehicle performance, including both fuel consumption and tailpipe emissions, but the real environmental benefit has to be evaluated considering the entire life of the products with a proper life cycle assessment. In this context, the present paper analyzes the environmental burden connected to the production of a safety-relevant aluminum high-pressure die-casting component for commercial vehicles (a suspension cross-beam) considering all the phases connected to its manufacture. The focus on aluminum high-pressure die casting reflects the current trend of the industry and its high energy consumption. This work shows a new method that deeply analyzes every single step of the component's production through the implementation of a wide database of primary data collected thanks to collaborations of some automotive supplier companies. This energy analysis shows significant environmental benefits of aluminum recycling.

  13. EVOLUTION OF AS—CAST MICROSTRUCTURES OF 356 ALUMINIUM ALLOY CAST BY LIQUIDUS CASTING

    Institute of Scientific and Technical Information of China (English)

    J.Dong; G.M.Lu; 等

    2003-01-01

    A new method (liquidus casting)was used for 356 Al alloy semi-solid slurry mak-ing.The structures of 356 Al alloy cast by a fe mould and semi-continuous casting machine at different temperatures were inves tigated.How the globular grains form was qlso discussed.The results show that either being cast by single Fe mould or semi-continuous machine,the microstructures are not conventional dendrites but fine and net-globular grains.The average grain size is smaller than 30μm and suitable enough for thixoforming,meanwhile it can improve the mechanical properties of fol-lowing products.Under the suitable casting velocity and cooling intensity,most of global grains prolong their global browth and collide with each other before dendritic growth because of the large amount of the nucleation sites.

  14. Improvement in Mechanical Properties of A356 Tensile Test Bars Cast in a Permanent Mold by Application of a Knife Ingate

    Science.gov (United States)

    Wang, Yaou; Schwam, David; Neff, David V.; Chen, Chai-Jung; Zhu, Xuejun

    2012-03-01

    As a standard test-bar permanent mold, the "Stahl" Mold has been widely used in foundries to assess the properties of cast alloys. However, inferior mechanical properties are often obtained with this mold due to shrinkage-induced microporosity in the gage section. In order to improve the mechanical properties, a design modification comprising a thin knife ingate between the feeder and test-bar cavity was evaluated in this work. The new design was studied by computer-aided simulation. Simulations predicted that the knife ingate improved the metal feeding capability and reduced the shrinkage microporosity at the gage section from 3 to 1 pct. Experimental verification work has been undertaken with aluminum alloy A356, and the results were analyzed by a statistics theory-based factorial analysis method. The new design resulted in main effects with ultimate tensile strength (UTS) improvement of 20 MPa (relative 12 pct) and elongation increment of 2 pct (relative 45 pct) for the as-cast test bars.

  15. Final Report, Volume 1, Metallurgical Evaluation of Cast Duplex Stainless Steels and their Weldments

    Energy Technology Data Exchange (ETDEWEB)

    Wen, Songqing; Lundin, Carl, W.; Batten, Greg, W.

    2005-09-30

    Duplex stainless steels (DSS) are being specified for chloride containing environments due to their enhanced pitting and stress corrosion cracking resistance. They exhibit improved corrosion performance over the austenitic stainless steels. Duplex stainless steels also offer improved strength properties and are available in various wrought and cast forms. Selected grades of duplex stainless steel castings and their welds, in comparison with their wrought counterparts, were evaluated, regarding corrosion performance and mechanical properties and weldability. Multiple heats of cast duplex stainless steel were evaluated in the as-cast, solution annealed (SA) static cast and SA centrifugal cast conditions, while their wrought counterparts were characterized in the SA condition and in the form of as-rolled plate. Welding, including extensive assessment of autogenous welds and a preliminary study of composite welds (shielded metal arc weld (SMAW)), was performed. The evaluations included critical pitting temperature (CPT) testing, intergranular corrosion (IGC) testing, ASTM A923 (Methods A, B and C), Charpy impact testing, weldability testing (ASTM A494), ferrite measurement and microstructural evaluations. In the study, the corrosion performances of DSS castings were characterized and assessed, including the wrought counterparts for comparison. The evaluation filled the pore of lack of data for cast duplex stainless steels compared to wrought materials. A database of the pitting corrosion and IGC behavior of cast and wrought materials was generated for a greater depth of understanding for the behavior of cast duplex stainless steel. In addition, improved evaluation methods for DSS castings were developed according to ASTM A923, A262, G48 and A494. The study revealed that when properly heat treated according to the specification, (1) DSS castings have equal or better pitting and intergranular corrosion resistance than their wrought counterparts; (2) Welding reduces the

  16. Final Report, Volume 1, Metallurgical Evaluation of Cast Duplex Stainless Steels and their Weldments

    Energy Technology Data Exchange (ETDEWEB)

    Wen, Songqing; Lundin, Carl, W.; Batten, Greg, W.

    2005-09-30

    Duplex stainless steels (DSS) are being specified for chloride containing environments due to their enhanced pitting and stress corrosion cracking resistance. They exhibit improved corrosion performance over the austenitic stainless steels. Duplex stainless steels also offer improved strength properties and are available in various wrought and cast forms. Selected grades of duplex stainless steel castings and their welds, in comparison with their wrought counterparts, were evaluated, regarding corrosion performance and mechanical properties and weldability. Multiple heats of cast duplex stainless steel were evaluated in the as-cast, solution annealed (SA) static cast and SA centrifugal cast conditions, while their wrought counterparts were characterized in the SA condition and in the form of as-rolled plate. Welding, including extensive assessment of autogenous welds and a preliminary study of composite welds (shielded metal arc weld (SMAW)), was performed. The evaluations included critical pitting temperature (CPT) testing, intergranular corrosion (IGC) testing, ASTM A923 (Methods A, B and C), Charpy impact testing, weldability testing (ASTM A494), ferrite measurement and microstructural evaluations. In the study, the corrosion performances of DSS castings were characterized and assessed, including the wrought counterparts for comparison. The evaluation filled the pore of lack of data for cast duplex stainless steels compared to wrought materials. A database of the pitting corrosion and IGC behavior of cast and wrought materials was generated for a greater depth of understanding for the behavior of cast duplex stainless steel. In addition, improved evaluation methods for DSS castings were developed according to ASTM A923, A262, G48 and A494. The study revealed that when properly heat treated according to the specification, (1) DSS castings have equal or better pitting and intergranular corrosion resistance than their wrought counterparts; (2) Welding reduces the

  17. Evaluation of porosity in Al alloy die castings

    Directory of Open Access Journals (Sweden)

    M. Říhová

    2012-01-01

    Full Text Available Mechanical properties of an Al-alloy die casting depend significantly on its structural properties. Porosity in Al-alloy castings is one of the most frequent causes of waste castings. Gas pores are responsible for impaired mechanical-technological properties of cast materials. On the basis of a complex evaluation of experiments conducted on AlSi9Cu3 alloy samples taken from the upper engine block which was die- cast with and without local squeeze casting it can be said that castings manufactured without squeeze casting exhibit maximum porosity in the longitudinal section. The area without local squeeze casting exhibits a certain reduction in mechanical properties and porosity increased to as much as 5%. However, this still meets the norms set by SKODA AUTO a.s.

  18. Process on cold crucible electromagnetic casting for titanium alloy

    Directory of Open Access Journals (Sweden)

    CHEN Rui-run

    2007-08-01

    Full Text Available The parameters and factors that influence the surface quality and macrostructure of titanium alloy with reactive properties under liquid state were studied experimentally using a cold crucible electromagnetic casting method. The variations in the process parameters have great impact on the surface quality and macrostructure of cast billets. Billets with crack free and smooth surfaces as well as directional solidified primary structures were obtained after the selection of optimized process parameters. The formation mechanisms of defects such as cracks and non-directional structural morphology were interpreted briefly. Finally, the casting of billets with good outer qualities and inner column grains has been attained successfully, which in turn gives a solid foundation for further development of the technology.

  19. Process on cold crucible electromagnetic casting for titanium alloy

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The parameters and factors that influence the surface quality and macrostructure of titanium alloy with reactive properties under liquid state were studied experimentally using a cold crucible electromagnetic casting method. The variations in the process parameters have great impact on the surface quality and macrostructure of cast billets. Billets with crack free and smooth surfaces as well as directional solidified primary structures were obtained after the selection of optimized process parameters. The formation mechanisms of defects such as cracks and non-directional structural morphology were interpreted briefly. Finally, the casting of billets with good outer qualities and inner column grains has been attained successfully, which in turn gives a solid foundation for further development of the technology.

  20. Nodular cast iron and casting monitoring

    Directory of Open Access Journals (Sweden)

    S. Pietrowski

    2008-10-01

    Full Text Available In this paper quality monitoring of nodular cast iron and casting made of it is presented. A control system of initial liquid cast iron to spheroidization, after spheroidization and inoculation with using of TDA method was shown. An application of an ultrasonic method to assessment of the graphite form and the metal matrix microstructure of castings was investigated.

  1. Nodular cast iron and casting monitoring

    OpenAIRE

    2008-01-01

    In this paper quality monitoring of nodular cast iron and casting made of it is presented. A control system of initial liquid cast iron to spheroidization, after spheroidization and inoculation with using of TDA method was shown. An application of an ultrasonic method to assessment of the graphite form and the metal matrix microstructure of castings was investigated.

  2. Effect of the concentrated heat flow treatment on the structure and the antiwear properties of cast iron

    Directory of Open Access Journals (Sweden)

    W. Orlowicz

    2009-04-01

    Full Text Available The influence of modes of surface fusion by electric arc plasma (GTAW method on the hardness and wear-resistance of plain cast ironwas studied. A possible mechanism of structural rearrangement in the processed material during the friction was analyzed. This mechanismis determined by specific behaviour of hardened martensitic structure under dynamic load. This martensitic structure forms a metalbasis of cementite eutectic under conditions of fast crystallisation.

  3. Properties and application spectrum of cast porous implants made of Ti-6Al-7Nb in coated and uncoated conditions

    OpenAIRE

    Guillén Girón, Teodolito

    2012-01-01

    This thesis presents the development, the characterization and the application of cast Ti-6Al-7Nb porous implants with respect to repair defects in cancellous bone. In the framework of this project, it was aimed at fabricating a porous implant with high mechanical strength to resist the applied load, a relatively low Young's modulus to prevent stress shielding phenomena, controlled cell dimensions to stimulate both mineral and collagen osseointegration, high porosity to guarantee intercon...

  4. Creep Properties of the As-Cast Al-A319 Alloy: T4 and T7 Heat Treatment Effects

    Science.gov (United States)

    Erfanian-Naziftoosi, Hamid R.; Rincón, Ernesto J.; López, Hugo F.

    2016-08-01

    In this work, the creep behavior of a commercial Al-A319 alloy was investigated in the temperature range of 413 K to 533 K (140 °C to 260 °C). Tensile creep specimens in the as-cast condition and after heat treating by solid solution (T4) and by aging (T7) were tested in a stress range varying from 60 to 170 MPa. It was found that steady-state creep strain rate was significantly low in the T7 condition when compared with either the T4 or as-cast alloy conditions. As a result, the time to failure behavior considerably increased. The experimentally determined creep exponents measured from the stress-strain curves were 4 for the as-cast alloy, 7.5 in the solid solution, and 9.5 after aging. In particular, after solid solution a grain substructure was found to develop which indicated that creep in a constant subgrain structure was active, thus accounting for the n exponent of 7.5. In the aged condition, a stress threshold is considered to account for the power law creep exponent n of 9.5. Moreover, It was found that the creep activation energy values were rather similar for the alloys in the as-cast (134 kJ/mol) and T4 (146 kJ/mol) conditions. These values are close to the one corresponding to pure Al self-diffusion (143 kJ/mol). In the aged alloy, the apparent creep activation energy (202 kJ/mol) exceeded that corresponding to Al self-diffusion. This deviation in activation energy is attributed to the effect of temperature on the alloy elastic modulus. Microstructural observations using transmission electron microscopy provided further support for the various dislocation-microstructure interactions exhibited by the alloy under the investigated creep conditions and implemented heat treatments.

  5. Structure and properties of cast and splat-quenched high-entropy Al-Cu-Fe-Ni-Si alloys

    Science.gov (United States)

    Bashev, V. F.; Kushnerov, O. I.

    2017-01-01

    The effect of the composition and cooling rate of the melt on the microhardness, phase composition, and fine-structure parameters of as-cast and splat-quenched (SQ) high-entropy (HE) Al-Cu-Fe-Ni-Si alloys was studied. The quenching was performed by conventional splat-cooling technique. The cooling rate was estimated to be 106 K/s. Components of the studied HE alloys were selected taking into account both criteria for designing and estimating their phase composition, which are available in the literature and based on the calculations of the entropy and enthalpy of mixing, and the difference between atomic radii of components as well. According to X-ray diffraction data, the majority of studied Al-Cu-Fe-Ni-Si compositions are two-phase HE alloys, the structure of which consists of disordered solid solutions with bcc and fcc structures. At the same time, the Al0.5CuFeNi alloy is single-phase in terms of X-ray diffraction and has an fcc structure. The studied alloys in the as-cast state have a dendritic structure, whereas, after splat quenching, the uniform small-grained structure is formed. It was found that, as the volume fraction of bcc solid solution in the studied HE alloys increases, the microhardness increases; the as-cast HE Al-Cu-Fe-Ni-Si alloys are characterized by higher microhardness compared to that of splat-quenched alloys. This is likely due to the more equilibrium multiphase state of as-cast alloys.

  6. Prediction of Microporosity in Shrouded Impeller Castings

    Energy Technology Data Exchange (ETDEWEB)

    Viswanathan, S. Nelson, C.D.

    1998-09-01

    The purpose of this Cooperative Research and Development Agreement (CRADA) between the Oak Ridge National Laboratory (ORNL) and Morris Bean and Company was to link computer models of heat and fluid flow with previously developed quality criteria for the prediction of microporosity in a Al-4.5% Cu alloy shrouded impeller casting. The results may be used to analyze the casting process design for the commercial production of 206 o alloy shrouded impeller castings. Test impeller castings were poured in the laboratory for the purpose of obtaining thermal data and porosity distributions. Also, a simulation of the test impeller casting was conducted and the results validated with porosity measurements on the test castings. A comparison of the predicted and measured microporosity distributions indicated an excellent correlation between experiments and prediction. The results of the experimental and modeling studies undertaken in this project indicate that the quality criteria developed for the prediction of microporosity in Al-4.5% Cu alloy castings can accurately predict regions of elevated microporosity even in complex castings such as the shrouded impeller casting. Accordingly, it should be possible to use quality criteria for porosity prediction in conjunction with computer models of heat and fluid flow to optimize the casting process for the production of shrouded impeller castings. Since high levels of microporosity may be expected to result in poor fatigue properties, casting designs that are optimized for low levels of microporosity should exhibit superior fatigue life.

  7. Prediction of Part Distortion in Die Casting

    Energy Technology Data Exchange (ETDEWEB)

    R. Allen Miller

    2005-03-30

    The die casting process is one of the net shape manufacturing techniques and is widely used to produce high production castings with tight tolerances for many industries. An understanding of the stress distribution and the deformation pattern of parts produced by die casting will result in less deviation from the part design specification, a better die design and eventually more productivity and cost savings. This report presents methods that can be used to simulate the die casting process in order to predict the deformation and stresses in the produced part and assesses the degree to which distortion modeling is practical for die casting at the current time. A coupled thermal-mechanical finite elements model was used to simulate the die casting process. The simulation models the effect of thermal and mechanical interaction between the casting and the die. It also includes the temperature dependant material properties of the casting. Based on a designed experiment, a sensitivity analysis was conducted on the model to investigate the effect of key factors. These factors include the casting material model, material properties and thermal interaction between casting and dies. To verify the casting distortion predictions, it was compared against the measured dimensions of produced parts. The comparison included dimensions along and across the parting plane and the flatness of one surface.

  8. Electron impact phenomena and the properties of gaseous ions

    CERN Document Server

    Field, F H; Massey, H S W; Brueckner, Keith A

    1970-01-01

    Electron Impact Phenomena and the Properties of Gaseous Ions, Revised Edition deals with data pertaining to electron impact and to molecular gaseous ionic phenomena. This book discusses electron impact phenomena in gases at low pressure that involve low-energy electrons, which result in ion formation. The text also describes the use of mass spectrometers in electron impact studies and the degree of accuracy obtained when measuring electron impact energies. This book also reviews relatively low speed electrons and the transitions that result in the ionization of the atomic system. This text the

  9. Viscous properties of new mould flux based on aluminate systemwith CeO2 for continuous casting of RE alloyed heat resistant steel

    Institute of Scientific and Technical Information of China (English)

    QI Jie; LIU Chengjun; LI Chunlong; JIANG Maofa

    2016-01-01

    The conventional mould fluxes can not be applied to the continuous casting of RE alloyed heat resistant steel, because se-vere slag-metal interface reactions occur generally in the mold. To restrain the interface reaction and improve conditions for continu-ous casting, a new mould flux based on aluminate system was devised. The viscous properties were investigated. Scanning electron microscopy and X-ray diffraction were applied to detect and characterize the crystalline phases in the continuous cooling process. The results showed that appropriate addition of CeO2 could avoid the precipitation of CaO and decrease the viscosity of the mould flux. Increasing the mass ratio of CaO/Al2O3, especially to a value exceeding 1, could worsen the stability of the mould flux. With a con-tent of less than 14 wt.%, Li2O could reduce the viscosity and breaking temperature, but its effect could be weakened for the pro-moted precipitation of LiAlO2. To obtain a mould flux with stable viscous properties, such as viscosity and breaking temperature, ap-propriate contents of CeO2 and Li2O should be controlled to around 10 wt.% and 14 wt.%, while the mass ratio of CaO/Al2O3 should not be more than 1.

  10. Effects of heat treatment on microstructure and mechanical properties of Mg-8Gd-3Y-0.5Zr (wt.% alloy fabricated by semi-continuous casting

    Directory of Open Access Journals (Sweden)

    Jun Yang

    2015-07-01

    Full Text Available The microstucture, mechanical properties and fracture behaviors of semi-continuous cast Mg-8Gd-3Y-0.5Zr (wt.%, GW83K alloy after different heat treatments were investigated. Almost all the eutectic compounds were dissolved into the matrix and there was no evident grain growth after optimum solution treatment at 500 °C for 4 h. Further ageing at low temperatures led to significant precipitation hardening, which strengthened the alloy. Peak-aged at 200 °C, the alloy had the highest ultimate tensile strength (UTS and lowest elongation at 395 MPa and 2.8%, respectively. When aged at 225 °C for 15 h, the alloy exhibited prominent mechanical performance with UTS and elongation of 363 MPa and 5.8 %, respectively. With regard to microstructure and tensile properties, the processes of 500 °C, 4 h + 225 °C, 15 h are selected as the optimal heat treatment conditions. The alloy under different conditions shows different fracture behaviors: in the as-cast alloy, a quasi-cleavage pattern is observed; after solution treatment, the alloy exhibits a trans-granular quasi-cleavage fracture; after being peak-aged at 200 °C and 225 °C, the fracture mode is a mixed mode of trans-granular and inter-granular fracture, in which the inter-granular mode is dominant in the alloy peak-aged at 200 °C.

  11. Fatigue properties of austempered ductile cast iron at room and elevated temperatures; Austemper kyujo kokuen chutetsu no chukoon ni okeru hiro tokusei

    Energy Technology Data Exchange (ETDEWEB)

    Fukuyama, K.; Hasegawa, N.; Inaga, K. [Gifu University, Gifu (Japan)

    1995-06-15

    Austempered ductile cast iron (ADI) is used widely as a structural material with high strength and toughness. However, since few studies have been made on investigation of fatigue properties at medium to high temperatures, this paper describes rotating bending tests carried out in temperature range between room temperature and 400{degree}C to investigate the fatigue properties and the fatigue crack generating behavior. The following results were obtained: the fatigue limit (fatigue strength after 10{sup 7} bendings) showed a remarkable maximizing phenomenon at temperatures around 300{degree}C; micronization of the base structure caused by transformation of residual austenite was recognized above 300{degree}C, and so was rise in the hardness; heating to this temperature led to rise in the Ms point, making the transformation occur more easily; the effect of repetitive stress causes a processing induced transformation; the temperature at which the transformation and the micronization are completed declines by about 50{degree}C lower than in the non-transformed region; and the fatigue fracture at middle to high temperatures is caused more frequently by internally existing graphite and development of cracks from very small casting cavities. 31 refs., 10 figs., 7 tabs.

  12. Effect of Substrate Movement Speed by Synchronous Rolling-casting Freeform Manufacturing for Metal on Microstructure and Mechanical Property of ZLl04 Aluminum Alloy Slurry

    Institute of Scientific and Technical Information of China (English)

    LUO Xiaoqiang; LI Zhengyang; CHEN Guangnan; XU Wanli; YAN Qingzhi

    2015-01-01

    Synchronous rolling-casting freeform manufacturing for Metal (SRCFMM) means that the refined liquid metal is continuously pressed out from the bottom of crucible. There is a horizontal movable plate beneath the outlet. The clearance between the outlet and the plate is about several hundred micrometers. SRCFMM, similar to additive manufacturing, implies layer by layer shaping and consolidation of feedstock to arbitrary conifgurations, normally using a computer controlled movable plate. The primary dendritic crystal is easily crushed by movement of substrate in the rolling-casting area. ZL104 was used as the test materials, determi-ning the control temperature by differential scanning thermal analysis (DSC), preparing a kind of samples by SR CFMM, then analyzing microstructures and mechanical property of the samples. Characteristics and distribution of the primary particles were assessed by optical microscopy (OM), scanning electron microscopy (SEM), energy dispersive spectrum (EDS) and image analysis software. Mechanical property of the samples was assessed by vickers hardness. The results show that the samples fabricated by SRCFMM have uniform structures and good performances with the velocity of the substrate controlled about 10 cm/s and temperature at about 580℃.

  13. Influence of Technological Parameters of Furane Mixtures on Shrinkage Creation in Ductile Cast Iron Castings

    Directory of Open Access Journals (Sweden)

    Vasková I.

    2014-10-01

    Full Text Available Ductile cast iron (GS has noticed great development in last decades and its boom has no analogue in history humankind. Ductile iron has broaden the use of castings from cast iron into areas, which where exclusively domains for steel castings. Mainly by castings, which weight is very high, is the propensity to shrinkage creation even higher. Shrinkage creation influences mainly material, construction of casting, gating system and mould. Therefore, the main realized experiment was to ascertain the influence of technological parameters of furane mixture on shrinkage creation in castings from ductile iron. Together was poured 12 testing items in 3 moulds forto determine and compare the impact of various technological parameters forms the propensity for shrinkage in the casting of LGG.

  14. Subtask 12D2: Baseline impact properties of vanadium alloys

    Energy Technology Data Exchange (ETDEWEB)

    Chung, H.M.; Loomis, B.A.; Smith, D.L. [Argonne National Lab., IL (United States)

    1995-03-01

    The objective of this work is to determine the baseline impact properties of vanadium-base alloys as a function of compositional variables. Up-to-date results on impact properties of unirradiated V, V-Ti, V-Cr-Ti and V-Ti-Si alloys are presented and reviewed in this paper, with an emphasis on the most promising class of alloys, i.e., V-(4-5)Cr-(3-5)Ti containing 400-1000 wppm Si. Database on impact energy and ductile-brittle transition temperature (DBTT) has been established from Charpy impact tests on small laboratory as well as production-scale heats. DBTT is influenced most significantly by Cr contents and, to a lesser extent, by Ti contents of the alloys. When combined contents of Cr and Ti were {le}10 wt.%, V-Cr-Ti alloys exhibit excellent impact properties, i.e., DBTT<-200{degrees}C and upper shelf energies of {approx}120-140 J/cm{sup 2}. Impact properties of the production-scale heat of the U.S. reference alloy V-4Cr- 4Ti were as good as those of the laboratory-scale heats. Optimal impact properties of the reference alloy were obtained after annealing the as-rolled products at 1000{degrees}C-1050{degrees}C for 1-2 h in high-quality vacuum. 17 refs., 6 figs., 2 tabs.

  15. Impact of Thermal Aging on the Microstructure Evolution and Mechanical Properties of Lanthanum-Doped Tin-Silver-Copper Lead-Free Solders

    Science.gov (United States)

    Sadiq, Muhammad; Pesci, Raphaël; Cherkaoui, Mohammed

    2013-03-01

    An extensive study is made to analyze the impact of pure lanthanum on the microstructure and mechanical properties of Sn-Ag-Cu (SAC) alloys at high temperatures. Different compositions are tested; the temperature applied for the isothermal aging is 150°C, and aging times of 10 h, 25 h, 50 h, 100 h, and 200 h are studied. Optical microscopy with cross-polarized light is used to follow the grain size, which is refined from 8 mm to 1 mm for as-cast samples and is maintained during thermal aging. Intermetallic compounds (IMCs) present inside the bulk Sn matrix affect the mechanical properties of the SAC alloys. Due to high-temperature exposure, these IMCs grow and hence their impact on mechanical properties becomes more significant. This growth is followed by scanning electron microscopy, and energy-dispersive spectroscopy is used for elemental mapping of each phase. A significant refinement in the average size of IMCs of up to 40% is identified for the as-cast samples, and the coarsening rate of these IMCs is slowed by up to 70% with no change in the interparticle spacing. Yield stress and tensile strength are determined through tensile testing at 20°C for as-cast samples and after thermal aging at 150°C for 100 h and 200 h. Both yield stress and tensile strength are increased by up to 20% by minute lanthanum doping.

  16. How property title impacts urban consolidation

    DEFF Research Database (Denmark)

    Easthope, Hazel; Warnken, Jan; Sherry, Cathy

    2014-01-01

    Continuing urbanisation is triggering an increase in multi-titled housing internationally. This trend has given rise to a substantial research interest in the social consequences of higher density living. Little enquiry, however, has been directed to examining how property title subdivisions...... tensions inherent in multi-title developments: i) tensions between individual and collective property rights, ii) tensions between the needs and responsibilities of different stakeholders, and iii) tensions inherent in the concurrent role of multi-title developments as governmental, market and civil...

  17. Preparation and properties of films cast from mixtures of poly(vinyl alcohol) and submicron particles prepared from amylose-palmitic acid inclusion complexes.

    Science.gov (United States)

    Fanta, George F; Selling, Gordon W; Felker, Frederick C; Kenar, James A

    2015-05-05

    The use of starch in polymer composites for film production has been studied for increasing biodegradability, improving film properties and reducing cost. In this study, submicron particles were prepared from amylose-sodium palmitate complexes both by rapidly cooling jet-cooked starch-palmitic acid mixtures and by acidifying solutions of starch-sodium palmitate complexes. Films were cast containing poly(vinyl alcohol) (PVOH) with up to 50% starch particles. Tensile strength decreased and Young's modulus increased with starch concentration, but percent elongations remained similar to controls regardless of preparation method or starch content. Microscopy showed particulate starch distribution in films made with rapidly cooled starch-palmitic acid particles but smooth, diffuse starch staining with acidified sodium palmitate complexes. The mild effects on tensile properties suggest that submicron starch particles prepared from amylose-palmitic acid complexes provide a useful, commercially viable approach for PVOH film modification.

  18. Study on Microstructure and Properties of ADI Pneumatic Cylinder Casting%ADI风镐缸体铸件组织与力学性能研究

    Institute of Scientific and Technical Information of China (English)

    黄之德; 王生玖

    2012-01-01

    研制了一种含Cu、Ni合金成分的风镐缸体铸件,比较了其厚壁和薄壁处铸态和等温淬火态的组织和性能.结果表明:奥贝球铁风镐缸体铸态基体组织为珠光体,存在少量铁素体,石墨比较细小,大部分为球形,圆整度较好,球状石墨数量多;加入适量的合金,采用合理的热处理工艺,等温淬火后,厚壁和薄壁处的金相组织皆由贝氏体、奥氏体和少量碳化物组成,此时ADI(等温淬火球墨铸铁)具有较高的强度和塑性,能满足风镐缸体的使用要求,提高风镐的使用寿命,具有良好的经济性.%The microstructurc and mechanical properties of thick and thin wall of austempeted ductile iron cylinder casting with Cu, Ni alloy as-cast and isothermal quenching state were compared. The results show that the as-cast microstructure consists of pearlite, and a small amount of ferrite, graphite is small, most of graphite is spherical shape, good round degree, nodular graphite number is many, microstructure of isothermal quenching consists of bainite, austenitic and a small amount of carbide, austempered ductile iron with high strength and plasticity after isothermal quenching, can meet the requirements for the use of pneumatic cylinder.

  19. Study of yttrium-based heavy rare earth compacted graphite cast iron high temperature properties%钇基重稀土蠕墨铸铁的高温性能研究

    Institute of Scientific and Technical Information of China (English)

    王敏毅; 黄颖; 林有希

    2012-01-01

    Compacted graphite cast iron was prepared by using of local rich resources of yttrium -based heavy rare earth. Several properties, such as tensile strength of gray cast iron and compacted graphite cast iron under condition of high temperature, oxidation weight increase value, percentage e-longation, heat fatigue resistance and linear expansion coefficient were discussed. Two kinds of castings linear regression equation for expansion coefficient were proposed. The results showed that fracturing properties of compacted graphite cast iron was dimple fracture in high temperature, and tensile strength of compacted graphite cast iron is mush stronger than that of gray cast iron in high temperature. In addition, compacted graphite cast iron behaved better in anti -oxidizing and anti -weight increasing than gray cast iron and the former thermal expansion coefficient is close to the latter. Moreover, they have similar linear expansion coefficient and phase change of grey cast iron shrinked much more severe than that compacted graphite cast iron.%利用钇基重稀土资源熔炼蠕墨铸铁,探讨高温条件下灰铸铁和蠕墨铸铁的抗拉强度、氧化增重值、伸长百分率、耐热疲劳性和线性膨胀系数等性能,同时用数理统计的方法推导出两种铸件线性膨胀系数的回归方程.结果表明:高温下蠕墨铸铁的断裂性质为韧窝断裂,其高温抗拉强度明显比灰铸铁高;蠕墨铸铁的抗氧化性和抗生长性均比灰铸铁好而导热系数与灰铸铁相近;灰铸铁和蠕墨铸铁的线性膨胀系数相近,但灰铸铁的相变收缩要比蠕墨铸铁强烈得多.

  20. Effect of inoculation on high temperature plastic properties of the centrifugally cast Cr-Ni-Nb steel

    Directory of Open Access Journals (Sweden)

    G. Tęcza

    2008-12-01

    Full Text Available From the centrifugally cast sleeve segments, in direction parallel to the axis, the specimens for mechanical tests were cut out in a way such as to get in one batch of the specimens a structure composed of columnar crystals and in another batch of the specimens a structure composed of equiaxial crystals. The specimens were subjected to a tensile test at the temperature of 820°C. It has been observed that the two zones of crystals differ quite considerably in the values of elongation, while preserving similar tensile strength levels.

  1. A Conceptual Framework of Green Certification Impact On Property Price

    Directory of Open Access Journals (Sweden)

    Abdullah Lizawati

    2016-01-01

    Full Text Available Green building is one of the sustainability dimensions in built environment. The issues of green building and its impact to the society have been increasingly discussed. Green certification is one of the components in measuring sustainable development and plays an important role as an assessment system to an individual building’s performance. The question arises whether the market understand and recognized the green certification. The objectives of this research are to discuss the issue pertaining to green value and the relationship between green certification and property price. The research emphasized on the understanding of property attributes focusing on green certification and the impact to the property price. Among the attributes identified are structural characteristics, location and neighborhood, and time attributes. Thus, this paper will discusses the review of literature on green development and the significance impact on property market in term of price and value. The green building development across the country could be classified as another sector in property markets that give significant impact to the real estate industry. As a result, a conceptual framework in assessing the impact of green certification is suggested to provide a significant input in developing the model of hedonic pricing for green building. This research may contribute to extend the body of knowledge in the area of green development and a suggested significant input will give much emphasize on the new valuation technique in valuing green building properties.

  2. Casting materials

    Energy Technology Data Exchange (ETDEWEB)

    Chaudhry, Anil R. (Xenia, OH); Dzugan, Robert (Cincinnati, OH); Harrington, Richard M. (Cincinnati, OH); Neece, Faurice D. (Lyndurst, OH); Singh, Nipendra P. (Pepper Pike, OH)

    2011-06-14

    A foam material comprises a liquid polymer and a liquid isocyanate which is mixed to make a solution that is poured, injected or otherwise deposited into a corresponding mold. A reaction from the mixture of the liquid polymer and liquid isocyanate inside the mold forms a thermally collapsible foam structure having a shape that corresponds to the inside surface configuration of the mold and a skin that is continuous and unbroken. Once the reaction is complete, the foam pattern is removed from the mold and may be used as a pattern in any number of conventional casting processes.

  3. The influence of Ti on the microstructure and tensile properties of cast Al–4.5Cu–0.3Mg alloy

    Energy Technology Data Exchange (ETDEWEB)

    Kamali, H. [School of Metallurgy and Materials Engineering, University of Tehran, P.O. Box 14395-731, Tehran (Iran, Islamic Republic of); Emamy, M., E-mail: emamy@ut.ac.ir [School of Metallurgy and Materials Engineering, University of Tehran, P.O. Box 14395-731, Tehran (Iran, Islamic Republic of); Razaghian, A. [Imam Khomeini International University, Qazvin (Iran, Islamic Republic of)

    2014-01-10

    Current study was undertaken to investigate the effect of different amounts of titanium (0.001–0.5 wt%) on the microstructure, tensile properties and quality index of a high strength aluminum alloy (Al–4.5 Cu–0.3Mg). It was found that this alloy is susceptible to hot tearing and at least 0.05 wt% Ti is necessary to remove such a defect. The microstructural studies of the alloy revealed that Ti addition reduces the grain size from 190 μm to 48 μm, but adding higher Ti content (>0.05 wt% Ti) does not change the grain size considerably. Further investigations on tensile tests revealed that the addition of Ti increases ultimate tensile strength (UTS) but reduces elongation values. T6 heat treatment improved UTS, elongation and quality index values of the casting. Fracture surfaces via scanning electron microscopy (SEM) revealed ductile fracture mode in both as-cast and heat-treated conditions. At higher Ti contents, the presence of Al{sub 3}Ti intermetallic on grain boundaries was found to be the favored path for crack growth.

  4. HA/nylon 6,6 porous scaffolds fabricated by salt-leaching/solvent casting technique: effect of nano-sized filler content on scaffold properties

    Directory of Open Access Journals (Sweden)

    Mehrabanian M

    2011-08-01

    Full Text Available Mehran Mehrabanian1, Mojtaba Nasr-Esfahani21Member of Young Researchers Club, Najafabad Branch, Islamic Azad University, Isfahan, Iran; 2Department of Materials Science and Engineering, Najafabad Branch, Islamic Azad University, Isfahan, IranAbstract: Nanohydroxyapatite (n-HA/nylon 6,6 composite scaffolds were produced by means of the salt-leaching/solvent casting technique. NaCl with a distinct range size was used with the aim of optimizing the pore network. Composite powders with different n-HA contents (40%, 60% for scaffold fabrication were synthesized and tested. The composite scaffolds thus obtained were characterized for their microstructure, mechanical stability and strength, and bioactivity. The microstructure of the composite scaffolds possessed a well-developed interconnected porosity with approximate optimal pore size ranging from 200 to 500 µm, ideal for bone regeneration and vascularization. The mechanical properties of the composite scaffolds were evaluated by compressive strength and modulus tests, and the results confirmed their similarity to cortical bone. To characterize bioactivity, the composite scaffolds were immersed in simulated body fluid for different lengths of time and results monitored by scanning electron microscopy and energy dispersive X-ray microanalysis to determine formation of an apatite layer on the scaffold surface.Keywords: scaffold, nanohydroxyapatite, nylon 6,6, salt-leaching/solvent casting, bioactivity

  5. Tensile properties of cast titanium alloys: Titanium-6Al-4V ELI and Titanium-5Al-2.5Sn ELI

    Science.gov (United States)

    Billinghurst, E. E., Jr.

    1992-01-01

    This work was performed to determine the tensile properties of cast, hot isostatic pressed (HIP'ed), and annealed titanium alloys, Ti-6Al-4V ELI and Ti-5Al-2.5Sn ELI, that are candidate materials for the space transportation main engine (STME) liquid hydrogen turbopump impeller. Samples of the cast alloys were HIP'ed, annealed, and machined into tensile specimens. The specimens were tested in air at ambient temperature (70 F) and also at -423 F in liquid hydrogen. The Ti-6Al-4V alloy had an average ultimate strength of 129.1 ksi at 70 F and 212.2 ksi at -423 F. The Ti-5Al-2.5Sn alloy had an average ultimate strength of 108.4 ksi at 70 degrees F and 185.0 ksi at -423 F. The ductility, as measured by reduction of area, for the Ti-6Al-4V averaged 15.2 percent at 70 F and 8.7 percent at -423 F, whereas for the Ti-5Al-2.5Sn alloy average reduction of area was 24.6 percent at 70 F and 11.7 percent at -423 F.

  6. Effect of intermediate annealing on the microstructure and mechanical property of ZK60 magnesium alloy produced by twin roll casting and hot rolling

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Hongmei, E-mail: hmchen@just.edu.cn [Provincial Key Lab of Advanced Welding Technology, Jiangsu University of Science and Technology, Zhenjiang 212003 (China); Zang, Qianhao [Provincial Key Lab of Advanced Welding Technology, Jiangsu University of Science and Technology, Zhenjiang 212003 (China); Yu, Hui [School of Materials Science and Engineering, Hebei University of Technology, Tianjin 300132 (China); Zhang, Jing [School of Metallurgical and Materials Engineering, Jiangsu University of Science and Technology, Zhang Jiagang 215600 (China); Jin, Yunxue [Provincial Key Lab of Advanced Welding Technology, Jiangsu University of Science and Technology, Zhenjiang 212003 (China)

    2015-08-15

    Twin roll cast (designated as TRC in short) ZK60 magnesium alloy strip with 3.5 mm thickness was used in this paper. The TRC ZK60 strip was multi-pass rolled at different temperatures, intermediate annealing heat treatment was performed when the thickness of the strip changed from 3.5 mm to 1 mm, and then continued to be rolled until the thickness reached to 0.5 mm. The effect of intermediate annealing during rolling process on microstructure, texture and room temperature mechanical properties of TRC ZK60 strip was studied by using OM, TEM, XRD and electronic universal testing machine. The introduction of intermediate annealing can contribute to recrystallization in the ZK60 sheet which was greatly deformed, and help to reduce the stress concentration generated in the rolling process. Microstructure uniformity and mechanical properties of the ZK60 alloy sheet were also improved; in particular, the room temperature elongation was greatly improved. When the TRC ZK60 strip was rolled at 300 °C and 350 °C, the room temperature elongation of the rolled sheet with 0.5 mm thickness which was intermediate annealed during the rolling process was increased by 95% and 72% than that of no intermediate annealing, respectively. - Highlights: • Intermediate annealing was introduced during hot rolling process of twin roll cast ZK60 alloy. • Intermediate annealing can contribute to recrystallization and reduce the stress concentration in the deformed ZK60 sheet. • Microstructure uniformity and mechanical properties of the ZK60 sheet were improved, in particular, the room temperature elongation. • The elongation of the rolled ZK60 sheet after intermediate annealed was increased by 95% and 72% than that of no intermediate annealing.

  7. Tape-cast and sintered β-tricalcium phosphate laminates for biomedical applications: Effect of milled Al2O3 fiber additives on microstructural and mechanical properties.

    Science.gov (United States)

    Tanimoto, Yasuhiro; Teshima, Masahiro; Nishiyama, Norihiro; Yamaguchi, Masaru; Hirayama, Satoshi; Shibata, Yo; Miyazaki, Takashi

    2012-11-01

    The aim of this study was to develop the tape-cast, laminated, and sintered β-tricalcium phosphate (β-TCP) with milled Al(2)O(3) fibers for biomedical applications. Moreover, the effects of Al(2)O(3)-fiber content on the microstructural and mechanical properties of the sintered β-TCP laminates were investigated. The milled Al(2)O(3) fibers were added at four different contents, namely 0, 5, 10, or 15 mass%, to the initial β-TCP slurry. Next, β-TCP green sheets were fabricated from the β-TCP slurry containing the milled Al(2)O(3) fibers by a tape-casting method. Finally, six plies of β-TCP monolayer sheet were laminated and sintered at a maximum temperature of 1100°C in a furnace. The results showed that there were large differences between the apparent porosities, dynamic hardness, and flexural properties of the sintered β-TCP laminates with Al(2)O(3)-fiber contents of 0 and 5 mass%, but few differences among laminates with fiber contents of 5, 10, and 15 mass%. This indicates that the addition of only 5 mass% of Al(2)O(3) fibers strongly affects the degree of sintering, corresponding to crystallization of the β-TCP matrix phase. Furthermore, the flexural moduli of our materials ranged from 10.7 to 16.0 GPa when the Al(2)O(3)-fiber content changed from 5 to 15 mass% and were the almost same as those of human bones reported by other researchers. In conclusion, sintered β-TCP laminates with Al(2)O(3) fibers have potential uses in a wide range of biomedical applications because the microstructural and mechanical properties of the sintered β-TCP laminates can be controlled by adding Al(2)O(3) fibers to the β-TCP.

  8. Technological parameters of die casting and quality of casting from EN AC46500 alloy

    Directory of Open Access Journals (Sweden)

    Š. Gašpár

    2016-07-01

    Full Text Available Die casting represents the highest technological level of metal mold casting. This technology enables production of almost all final products without necessity of further processing. The important aspect of efficiency and production is a proper casting parameters setting. In the submitted paper following die casting parameters are analyzed: plunger pressing speed and pressure. The studied parameters most significantly affect a qualitative of castings from EN AC46500 alloy and they influence the most a gained porosity level as well as basic mechanical properties represented by permanent deformations.

  9. Impact Behavior and Fracture Mechanism of Ductile Cast Iron with Minor Nickel Addition at Low Temperature%低镍球墨铸铁低温冲击性能及断裂机理研究

    Institute of Scientific and Technical Information of China (English)

    陈江; 黄兴民; 高杰维; 董海; 戴光泽

    2012-01-01

    使用激光共聚焦显微镜、扫描电镜和示波冲击等实验手段研究了镍元素(0.0%~0.9%,质量分数,下同)对球墨铸铁的微观组织和低温冲击性能的影响,对低温断裂机理进行了探讨.结果表明:含镍0.7%退火态球墨铸铁的韧脆转变温度低于-60℃,其-70℃下冲击功高于12J;适量镍元素添加能有效地细化晶粒和强化基体,改善球墨铸铁的低温冲击性能.%Utilizing laser confocal microscopy, SEM, instrumented impact and other experimental methods, the influence of nickel content(0. 0%-0. 9%,mass fraction, the same below) on the micro-structure and low temperature impact toughness of ductile cast iron(DCI) was investigated. The fracture mechanism of DCIs was studied further at different temperatures by using scanning electronic microscopy (SEM). The results show that ductile-to-brittle transition temperature of as-annealed DCIs with 0. 7% Ni content is lower than —60℃ , the impact energy of Charpy-type test is still higher than 12J at —70℃. Minor Ni addition of proper quantities might favor the grain refinement and matrix strengthen, low temperature impact toughness properties of DCIs are markedly improved.

  10. BP Neural Network of Continuous Casting Technological Parameters and Secondary Dendrite Arm Spacing of Spring Steel

    Institute of Scientific and Technical Information of China (English)

    HANG Li-hong; WANG Ai-guo; TIAN Nai-yuan; ZHANG Wei-cun; FAN Qiao-li

    2011-01-01

    The continuous casting technological parameters have a great influence on the secondary dendrite arm spacing of the slab, which determines the segregation behavior of materials. Therefore, the identification of technological parameters of continuous casting process directly impacts the property of slab. The relationships between continuous casting technological parameters and cooling rate of slab for spring steel were built using BP neural network model, based on which, the relevant secondary dendrite arm spacing was calculated. The simulation calculation was also carried out using the industrial data. The simulation results show that compared with that of the traditional method, the absolute error of calculation result obtained with BP neural network model reduced from 0. 015 to 0. 0005, and the relative error reduced from 6, 76 % to 0.22 %. BP neural network model had a more precise accuracy in the optimization of continuous casting technological parameters.

  11. Nondestructive Evaluation of the Austempered Ductile Cast Irons

    Energy Technology Data Exchange (ETDEWEB)

    Lee, S. S.; Lee, S. K. [Korea Standards Research Institute, Daejeon (Korea, Republic of)

    1989-05-15

    Austempered ductile cast iron (ADI) which has been recently developed shows good mechanical properties. These properties are related to the microstructure which is greatly affected by processing variables such as austempering time and temperature. In this study, the relationships between mechanical properties from impact test, and hardness test and the results from ultrasonic velocity measurement and electrical resistivity measurement are studied on the ADI samples which are heat treated at different austempering temperature and time. From the results, we conclude the followings. The ultrasonic velocity measurement could be used for the study of austempering reaction mechanism. The electrical resistivity measurement could be used as quality assurance technique for the ADI

  12. EVOLUTION OF AS-CAST MICROSTRUCTURES OF 356 ALUMINIUM ALLOY CAST BY LIQUIDUS CASTING

    Institute of Scientific and Technical Information of China (English)

    J. Dong; G.M. Lu; J.Z. Cui; Z.H. Zhao

    2003-01-01

    A new method (liquidus casting) was used for 356 Al alloy semi-solid slurry mak-ing. The structures of 356 Al alloy cast by a Fe mould and semi-continuous castingmachine at different temperatures were investigated. How the globular grains formwas also discussed. The results show that either being cast by single Fe mould orsemi-continuous machine, the microstructures are not conventional dendrites but fineand net-globular grains. The average grain size is smaller than 30μm and suitableenough for thixoforming, meanwhile it can improve the mechanical properties of fol-lowing products. Under the suitable casting velocity and cooling intensity, most ofglobal grains prolong their global growth and collide with each other before dendriticgrowth because of the large amount of the nucleation sites.

  13. Biomaterials by freeze casting.

    Science.gov (United States)

    Wegst, Ulrike G K; Schecter, Matthew; Donius, Amalie E; Hunger, Philipp M

    2010-04-28

    The functional requirements for synthetic tissue substitutes appear deceptively simple: they should provide a porous matrix with interconnecting porosity and surface properties that promote rapid tissue ingrowth; at the same time, they should possess sufficient stiffness, strength and toughness to prevent crushing under physiological loads until full integration and healing are reached. Despite extensive efforts and first encouraging results, current biomaterials for tissue regeneration tend to suffer common limitations: insufficient tissue-material interaction and an inherent lack of strength and toughness associated with porosity. The challenge persists to synthesize materials that mimic both structure and mechanical performance of the natural tissue and permit strong tissue-implant interfaces to be formed. In the case of bone substitute materials, for example, the goal is to engineer high-performance composites with effective properties that, similar to natural mineralized tissue, exceed by orders of magnitude the properties of its constituents. It is still difficult with current technology to emulate in synthetic biomaterials multi-level hierarchical composite structures that are thought to be the origin of the observed mechanical property amplification in biological materials. Freeze casting permits to manufacture such complex, hybrid materials through excellent control of structural and mechanical properties. As a processing technique for the manufacture of biomaterials, freeze casting therefore has great promise.

  14. The UK Casting Industry

    Institute of Scientific and Technical Information of China (English)

    Jincheng Liu

    2006-01-01

    The casting production in the UK in 2004 is presented and analysed. The UK casting industry has played an important role in world casting and manufacturing production. However recent years the rapid development of some developing countries has been shifting the casting production from the western industrialized countries including the UK. The UK casting industry and associated research and technology organizations, universities have been working together very hard to face the serious competition to make the UK casting industry have a sustainable future. The UK casting industry remains strong and plays an important role in world casting and manufacturing production.

  15. Effect of casting parameters and deformation on microstructure evolution of twin-roll casting magnesium alloy AZ31

    Institute of Scientific and Technical Information of China (English)

    JU Dong-ying; HU Xiao-dong

    2006-01-01

    Twin roll casting method is a promising route to directly produce magnesium alloy strip. It is a rapid solidification process with high temperature gradient combined with thermal flow and rolling deformation in the casting region. As-cast strip with proper microstructure is requested to serve as next rolling feedstock. However the microstructure of as-cast strip is sensitive for casting conditions during the casting process and the as-cast microstructure greatly affects the mechanical properties. In this work,the effect of casting speed,pouring temperature,deformation as well as anneal process on microstructure and mechanical properties were investigated. The results revels that twin-roll casting process can effectively refine the grain size,improve the morphology and distribution states of Mg17Al12. The homogenization treatment time can be shorted for the fine microstructure and lower the cost dramatically for the next forming process.

  16. Letter Report: LAW Simulant Development for Cast Stone Screening Test

    Energy Technology Data Exchange (ETDEWEB)

    Russell, Renee L.; Westsik, Joseph H.; Swanberg, David J.; Eibling, Russell E.; Cozzi, Alex; Lindberg, Michael J.; Josephson, Gary B.; Rinehart, Donald E.

    2013-03-27

    More than 56 million gallons of radioactive and hazardous waste are stored in 177 underground storage tanks at the U.S. Department of Energy’s (DOE’s) Hanford Site in southeastern Washington State. The Hanford Tank Waste Treatment and Immobilization Plant (WTP) is being constructed to treat the wastes and immobilize them in a glass waste form. The WTP includes a pretreatment facility to separate the wastes into a small volume of high-level waste (HLW) containing most of the radioactivity and a larger volume of low-activity waste (LAW) containing most of the nonradioactive chemicals. The HLW will be converted to glass in the HLW vitrification facility for ultimate disposal at an offsite federal repository. At least a portion (~35%) of the LAW will be converted to glass in the LAW vitrification facility and will be disposed of onsite at the Integrated Disposal Facility (IDF). The pretreatment and HLW vitrification facilities will have the capacity to treat and immobilize the wastes destined for each facility. However, a second facility will be needed for the expected volume of additional LAW requiring immobilization. A cementitious waste form known as Cast Stone is being considered to provide the required additional LAW immobilization capacity. The Cast Stone waste form must be acceptable for disposal in the IDF. The Cast Stone waste form and immobilization process must be tested to demonstrate that the final Cast Stone waste form can comply with waste acceptance criteria for the IDF disposal facility and that the immobilization processes can be controlled to consistently provide an acceptable waste form product. Further, the waste form must be tested to provide the technical basis for understanding the long term performance of the waste form in the IDF disposal environment. These waste form performance data are needed to support risk assessment and performance assessment (PA) analyses of the long-term environmental impact of the waste disposal in the IDF. A

  17. CA Investment Casting Process of Complex Castings

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    CA (Computer aided) investment casting technique used in superalloy castings of aerospace engine parts was presented. CA investment casting integrated computer application, RP (Rapid Prototyping) process, solidification simulation and investment casting process. It broke the bottle neck of making metal die. Solid model of complex parts were produced by UGII or other software, then translated into STL(Stereolithography) file, after RP process of SLS(Selective Laser Sintering), wax pattern used in investment ...

  18. Fabrication of ZnO Nanowires Arrays by Anodization and High-Vacuum Die Casting Technique, and Their Piezoelectric Properties.

    Science.gov (United States)

    Kuo, Chin-Guo; Chang, Ho; Wang, Jian-Hao

    2016-03-24

    In this investigation, anodic aluminum oxide (AAO) with arrayed and regularly arranged nanopores is used as a template in the high-vacuum die casting of molten zinc metal (Zn) into the nanopores. The proposed technique yields arrayed Zn nanowires with an aspect ratio of over 600. After annealing, arrayed zinc oxide (ZnO) nanowires are obtained. Varying the anodizing time yields AAO templates with thicknesses of approximately 50 μm, 60 μm, and 70 μm that can be used in the fabrication of nanowires of three lengths with high aspect ratios. Experimental results reveal that a longer nanowire generates a greater measured piezoelectric current. The ZnO nanowires that are fabricated using an alumina template are anodized for 7 h and produce higher piezoelectric current of up to 69 pA.

  19. Fabrication of ZnO Nanowires Arrays by Anodization and High-Vacuum Die Casting Technique, and Their Piezoelectric Properties

    Directory of Open Access Journals (Sweden)

    Chin-Guo Kuo

    2016-03-01

    Full Text Available In this investigation, anodic aluminum oxide (AAO with arrayed and regularly arranged nanopores is used as a template in the high-vacuum die casting of molten zinc metal (Zn into the nanopores. The proposed technique yields arrayed Zn nanowires with an aspect ratio of over 600. After annealing, arrayed zinc oxide (ZnO nanowires are obtained. Varying the anodizing time yields AAO templates with thicknesses of approximately 50 μm, 60 μm, and 70 μm that can be used in the fabrication of nanowires of three lengths with high aspect ratios. Experimental results reveal that a longer nanowire generates a greater measured piezoelectric current. The ZnO nanowires that are fabricated using an alumina template are anodized for 7 h and produce higher piezoelectric current of up to 69 pA.

  20. Influence of cold rolling direction on texture, inhibitor and magnetic properties in strip-cast grain-oriented 3% silicon steel

    Science.gov (United States)

    Fang, F.; Lu, X.; Zhang, Y. X.; Wang, Y.; Jiao, H. T.; Cao, G. M.; Yuan, G.; Xu, Y. B.; Misra, R. D. K.; Wang, G. D.

    2017-02-01

    An unconventional cold rolling scheme (inclined rolling at 0°, 30°, 45°, 90° during second-stage cold rolling process) was adopted to process grain-oriented silicon steel based on strip casting process. The influences of inclination angles on microstructure, texture, inhibitor and magnetic properties were studied by a combination of EBSD, XRD and TEM. It was found that the α-fiber texture was weakened and γ-fiber was strengthened in cold rolled sheet with increase in inclination angle. The primary recrystallization sheet exhibited more homogeneous microstructure with relatively strong γ-fiber, medium α-fiber texture, weak λ-fiber texture and Goss component at high inclination angles. Fine and homogeneous inhibitors were obtained after primary annealing with increase in inclination angle from 0° to 90° because of more uniform deformation after inclined rolling. The grain-oriented silicon steel experienced completely secondary recrystallization at various inclination angles after final annealing process, with superior magnetic properties at 0° and 90°. Furthermore, Goss nuclei capable of final secondary recrystallization in strip casting process newly formed both in-grain shear bands and grain boundaries region during second-stage cold rolling and subsequent annealing process, which is different from the well-accepted results that Goss texture originated from the subsurface layer of the hot rolled sheet or during intermediate annealing process. In addition, the Goss texture that nucleated in-grain shear bands was weaker but more accurate as compared to that in grain boundaries region.

  1. As-Cast Acicular Ductile Aluminum Cast Iron

    Institute of Scientific and Technical Information of China (English)

    S M Mostafavi Kashani; S M A Boutorabi

    2009-01-01

    The effects of nickel (2.2%)and molybdenum (0.6%)additions on the kinetics, microstructure, and me-chanical properties of ductile aluminum cast iron were studied under the as-cast and tempered conditions. Test bars machined from cast to size samples were used for mechanical and metallurgical studies. The results showed that adding nickel and molybdenum to the base iron produced an upper bainitic structure, resulting in an increase in strength and hardness. The same trend was shown when the test bars were tempered at 300 ℃ in the range of 300℃ to 400 ℃. The elongation increased with increasing the temperature from 300 ℃ to 400 ℃. The carbon content of the retained austenite also increased with increasing the temperature. The results also showed that the kinetics, mi-crostructure, and mechanical properties of this iron were similar to those of Ni-Mo alloyed silicon ductile iron.

  2. Impact of dilution on the microstructure and properties of Ni-based 625 alloy coatings

    Directory of Open Access Journals (Sweden)

    Tiago Jose Antoszczyszyn

    2014-06-01

    Full Text Available Nickel-based alloy IN 625 is used to protect components of aircrafts, power generation and oil refinery due to an association of toughness and high corrosion resistance. These properties are associated with the chemical composition and microstructure of coatings which depend on the processing parameters and the composition of the component being protected. This paper assessed impact of dilution on the microstructure and properties of the Ni alloy IN 625 deposited by Plasma Transferred Arc (PTA on two substrates: carbon steel API 5L and stainless steel AISI 316L. Differences due to the interaction with the substrate were maximized analyzing single layer coatings, processed with three deposition current: 120, 150 and 180 A. Correlation with a cast Nickel-based alloy sample contributed to assess the impact of dilution on coatings. Dilution was determined by the area ratio and Vickers hardness measured on the transverse section of coatings. Scanning electron and Laser confocal microscopy and X-ray diffraction analysis were carried out to characterize the microstructure. Results indicated the increasing dilution with the deposition current was deeply influenced by the substrate. Dilution ranging from 5 to 29% was measured on coatings processed on the API 5L steel and from 22 to 51% on the low thermal conductivity AISI 316L steel substrate. Differences on the microstructure and properties of coatings can be associated with the interaction with each substrate. Higher fraction of carbides account for the higher coating hardness when processing on API 5L whereas the low thermal conductivity of AISI 316L and the higher Fe content in solid solution contributed to the lower hardness of coatings.

  3. Light metal compound casting

    Institute of Scientific and Technical Information of China (English)

    Konrad J.M.PAPIS; Joerg F.LOEFFLER; Peter J.UGGOWITZER

    2009-01-01

    'Compound casting'simplifies joining processes by directly casting a metallic melt onto a solid metal substrate. A continuously metallurgic transition is very important for industrial applications, such as joint structures of spaceframe constructions in transport industry. In this project, 'compound casting' of light metals is investigated, aiming at weight-saving. The substrate used is a wrought aluminium alloy of type AA5xxx, containing magnesium as main alloying element. The melts are aluminium alloys, containing various alloying elements (Cu, Si, Zn), and magnesium. By replacing the natural oxygen layer with a zinc layer, the inherent wetting difficulties were avoided, and compounds with flawless interfaces were successfully produced (no contraction defects, cracks or oxides). Electron microscopy and EDX investigations as well as optical micrographs of the interfacial areas revealed their continu-ously metallic constitution. Diffusion of alloying elements leads to heat-treatable microstructures in the vicinity of the joining interfaces in Al-Al couples. This permits significant variability of mechanical properties. Without significantly cutting down on wettability, the formation of low-melting intermetallic phases (Al3Mg2 and AI12Mg17 IMPs) at the interface of Al-Mg couples was avoided by applying a protec-tive coating to the substrate.

  4. The ancient Chinese casting techniques

    OpenAIRE

    2011-01-01

    In the course of Chinese civilization, which lasted more than 5,000 years, casting production has made a huge contribution. In this paper, some representative metal castings were presented. According to their forming techniques, they can be grouped into stone mould casting, clay mould casting, ablation casting, lost wax casting, stack casting, permanent mould casting, sand casting, etc. According to their materials, they can be categorized into tin bronze, bimetallic bronze, malleable cast ir...

  5. Iron/Phosphorus Alloys for Continuous Casting

    Science.gov (United States)

    Dufresne, E. R.

    1986-01-01

    Continuous casting becomes practicable because of reduced eutectic temperature. Experimental ferrous alloy has melting point about 350 degrees C lower than conventional steels, making possible to cast structural members and eliminating need for hot rolling. Product has normal metal structure and good physical properties. Process used to make rails, beams, slabs, channels, and pipes.

  6. Homogenity of Die Casting and Returning Material

    Directory of Open Access Journals (Sweden)

    J. Malik

    2012-04-01

    Full Text Available Homogeneity of die castings is influenced by wide range of technological parameters as piston velocity in filling chamber of die casting machine, filling time of mould cavity, temperature of cast alloy, temperature of the mould, temperature of filling chamber, surface pressure on alloy during mould filling, final pressure and others. Based on stated parameters it is clear, that main parameters of die casting are filling time of die mould cavity and velocity of the melt in the ingates. Filling time must ensure the complete filling of the mould cavity before solidification process can negatively influence it. Among technological parameters also belong the returning material, which ratio in charge must be constrained according to requirement on final homogeneity of die castings. With the ratio of returning material influenced are the mechanical properties of castings, inner homogeneity and chemical composition.

  7. A Repeated Impact Method and Instrument to Evaluate the Impact Fatigue Property of Drillpipe

    Science.gov (United States)

    Lin, Yuanhua; Li, Qiang; Sun, Yongxing; Zhu, Hongjun; Zhou, Ying; Xie, Juan; Shi, Taihe

    2013-04-01

    It is well known that drillpipe failures are a pendent problem in drilling engineering. Most of drillpipe failures are low amplitude-repeated impact fatigue failures. The traditional method is using Charpy impact test to describe the fracture property of drillpipe, but it cannot veritably characterize the impact fatigue property of drillpipe under low amplitude-repeated impact. Based on the Charpy impact and other methods, a repeated impact method and instrument have been proposed to simulate the low amplitude-repeated impact of downhole conditions for drillpipe. Then, a series of tests have been performed using this instrument. Test results demonstrate the drillpipe upset transition area nonhomogeneity is more severe than drillpipe body, which is the key factor that leads to washout and fracture frequently of it. As the one time impact energy increases, the repeated impact times decrease exponentially, therefore, the rotational speed has a great effect on the fatigue life of drillpipe, and it is vital to select a suitable rotational speed for drilling jobs. In addition, based on SEM fractographs we found that the fracture surface of repeated impact is similar to the fatigue fracture, and there are many low cycle fatigue characteristic features on fracture surface that reveal very good agreement with the features of drillpipe fatigue failures in the field.

  8. Microstructure and mechanical properties of Mg-Gd-Y-Zr alloy cast by metal mould and lost foam casting%金属型铸造和消失模铸造Mg-Gd-Y-Zr合金的组织结构和力学性能

    Institute of Scientific and Technical Information of China (English)

    李吉林; 陈荣石; 柯伟

    2011-01-01

    研究金属型铸造和消失模铸造Mg-10.1Gd-3.74Y-0.25zr(质量分数,%)合金的组织结构和力学性能.结果表明:采用两种铸造工艺得到的合金具有相似的铸态组织,均由а-Mg固溶体相、а-Mg+Mg(Gd,Y)5共晶相和立方状Mg5(Gd,Y)相组成:但金属型铸造合金的晶粒尺寸明显小于消失模铸造合金.经525℃,6 h固溶处理后,合金中的共晶相完全溶入基体中,而立方状Mg5(Gd,Y)相仍然存在.固溶处理后的合金在225℃时效处理24 h后达到硬化峰值.经过时效处理后,消失模铸造合金和金属型铸造合金的室温抗拉强度分别提高到285 MPa和325 MPa,但两者的屈服强度相差不大.与金属型铸造相比,消失模铸造过程中合金的冷却速度相对较慢,而且消失模铸造Mg-Gd-Y-zr合金铸件更容易产生缩松等铸造缺陷,这是造成两种合金强度差异的主要原因.%The microstructure and mechanical properties of Mg-10.1 Gd-3.74Y-0.25Zr (mass fraction, %) alloy (GW104 alloy) cast by metal mould casting (MMC) and lost foam casting (LFC) were evaluated, respectively. It is revealed that different forming modes do not influence the phase composition of as-cast alloy. In the as-cast specimens, the microstructures are similar and composed of size of the alloy produced by metal mould casting is smaller than that by lost foam casting. The eutectic compound of the alloy is completely dissolved after solution treatment at 525 ℃ for 6 h, while the Mg5(Gd, Y) phase still exists after solution treatment. After peak-ageing, the lost foam cast alloy exhibits the maximum ultimate tensile strength of 285 MPa, and metal mould cast specimen 325 MPa at room temperature, while the tensile yield strengths of them are comparable. It can be concluded that GWl04 alloy cast by lost foam casting possesses similar microstructure and evidently lower mechanical strength compared with metal mould cast alloy, due to slow solidification rate and proneness to form

  9. Recent Impacts on Mars: Cluster Properties and Seismic Signal Predictions

    Science.gov (United States)

    Justine Daubar, Ingrid; Schmerr, Nicholas; Banks, Maria; Marusiak, Angela; Golombek, Matthew P.

    2016-10-01

    Impacts are a key source of seismic waves that are a primary constraint on the formation, evolution, and dynamics of planetary objects. Geophysical missions such as InSight (Banerdt et al., 2013) will monitor seismic signals from internal and external sources. New martian craters have been identified in orbital images (Malin et al., 2006; Daubar et al., 2013). Seismically detecting such impacts and subsequently imaging the resulting craters will provide extremely accurate epicenters and source crater sizes, enabling calibration of seismic velocities, the efficiency of impact-seismic coupling, and retrieval of detailed regional and local internal structure.To investigate recent impact-induced seismicity on Mars, we have assessed ~100 new, dated impact sites. In approximately half of new impacts, the bolide partially disintegrates in the atmosphere, forming multiple craters in a cluster. We incorporate the resulting, more complex, seismic effects in our model. To characterize the variation between sites, we focus on clustered impacts. We report statistics of craters within clusters: diameters, morphometry indicating subsurface layering, strewn-field azimuths indicating impact direction, and dispersion within clusters indicating combined effects of bolide strength and elevation of breakup.Measured parameters are converted to seismic predictions for impact sources using a scaling law relating crater diameter to the momentum and source duration, calibrated for impacts recorded by Apollo (Lognonne et al., 2009). We use plausible ranges for target properties, bolide densities, and impact velocities to bound the seismic moment. The expected seismic sources are modeled in the near field using a 3-D wave propagation code (Petersson et al., 2010) and in the far field using a 1-D wave propagation code (Friederich et al., 1995), for a martian seismic model. Thus we calculate the amplitudes of seismic phases at varying distances, which can be used to evaluate the detectability

  10. Friction Stir Welding in Wrought and Cast Aluminum Alloys: Weld Quality Evaluation and Effects of Processing Parameters on Microstructure and Mechanical Properties

    Science.gov (United States)

    Pan, Yi; Lados, Diana A.

    2017-01-01

    Friction stir welding (FSW) is a solid-state process widely used for joining similar and dissimilar materials for critical applications in the transportation sector. Understanding the effects of the process on microstructure and mechanical properties is critical in design for structural integrity. In this study, four aluminum alloy systems (wrought 6061-T651 and cast A356, 319, and A390) were processed in both as-fabricated and pre-weld heat-treated (T6) conditions using various processing parameters. The effects of processing and heat treatment on the resulting microstructures, macro-/micro-hardness, and tensile properties were systematically investigated and mechanistically correlated to changes in grain size, characteristic phases, and strengthening precipitates. Tensile tests were performed at room temperature both along and across the welding zones. A new method able to evaluate weld quality (using a weld quality index) was developed based on the stress concentration calculated under tensile loading. Optimum processing parameter domains that provide both defect-free welds and good mechanical properties were determined for each alloy and associated with the thermal history of the process. These results were further related to characteristic microstructural features, which can be used for component design and materials/process optimization.

  11. Friction Stir Welding in Wrought and Cast Aluminum Alloys: Weld Quality Evaluation and Effects of Processing Parameters on Microstructure and Mechanical Properties

    Science.gov (United States)

    Pan, Yi; Lados, Diana A.

    2017-04-01

    Friction stir welding (FSW) is a solid-state process widely used for joining similar and dissimilar materials for critical applications in the transportation sector. Understanding the effects of the process on microstructure and mechanical properties is critical in design for structural integrity. In this study, four aluminum alloy systems (wrought 6061-T651 and cast A356, 319, and A390) were processed in both as-fabricated and pre-weld heat-treated (T6) conditions using various processing parameters. The effects of processing and heat treatment on the resulting microstructures, macro-/micro-hardness, and tensile properties were systematically investigated and mechanistically correlated to changes in grain size, characteristic phases, and strengthening precipitates. Tensile tests were performed at room temperature both along and across the welding zones. A new method able to evaluate weld quality (using a weld quality index) was developed based on the stress concentration calculated under tensile loading. Optimum processing parameter domains that provide both defect-free welds and good mechanical properties were determined for each alloy and associated with the thermal history of the process. These results were further related to characteristic microstructural features, which can be used for component design and materials/process optimization.

  12. Comparison of Impact Properties for Carbon and Low Alloy Steels

    Institute of Scientific and Technical Information of China (English)

    O.H. Ibrahim

    2011-01-01

    The impact properties of hot rolled carbon steel (used for the manufacture of reinforcement steel bars) and the quenched & tempered (Q&T) low alloy steel (used in the pressure vessel industry) were determined. The microstructure of the hot rolled carbon steel contained ferrite/pearlite phases, while that of the quenched and tempered low alloy steel contained bainite structure. Impact properties were determined for both steels by instrumented impact testing at temperatures between -150 and 200℃. The impact properties comprised total impact energy, ductile to brittle transition temperature, crack initiation and propagation energy, brittleness transition temperature and cleavage fracture stress. The Q&T low alloy steel displayed much higher resistance to ductile fracture at high test temperatures, while its resistance to brittle fracture at low test temperatures was a little higher than that of the hot rolled carbon steel. The results were discussed in relation to the difference in the chemical composition and microstructure for the two steels.

  13. Characteristics of cast and welded aluminium nodes

    Energy Technology Data Exchange (ETDEWEB)

    Oedegaard, J.; Polanco, M.; Syvertsen, F.; Sund, H. [SINTEF, Trondheim (Norway). Materials Technology

    2000-07-01

    It has been demonstrated that sand cast aluminium nodes can be produced with properties that gives competitive energy absorption capacity compared with welded aluminium nodes. Sand cast nodes could be mass-produced to a low cost and with properties that should be competitive to the properties of fusion welded nodes. This may open for simpler and more cost-effective joint alternatives when production of aluminium space-frames and subassemblies are in focus. Cast nodes joined to extruded members by adhesive bonding could be one example. (orig.)

  14. Effects of chromium and nitrogen content on the microstructures and mechanical properties of as-cast Co-Cr-Mo alloys for dental applications.

    Science.gov (United States)

    Yoda, Keita; Suyalatu; Takaichi, Atsushi; Nomura, Naoyuki; Tsutsumi, Yusuke; Doi, Hisashi; Kurosu, Shingo; Chiba, Akihiko; Igarashi, Yoshimasa; Hanawa, Takao

    2012-07-01

    The microstructure and mechanical properties of as-cast Co-(20-33)Cr-5Mo-N alloys were investigated to develop ductile Co-Cr-Mo alloys without Ni addition for dental applications that satisfy the requirements of the type 5 criteria in ISO 22674. The effects of the Cr and N contents on the microstructure and mechanical properties are discussed. The microstructures were evaluated using scanning electron microscopy with energy-dispersive X-ray spectroscopy (EDS), X-ray diffractometry (XRD), and electron back-scattered diffraction pattern analysis. The mechanical properties were evaluated using tensile testing. The proof strength and elongation of N-containing 33Cr satisfied the type 5 criteria in ISO 22674. ε-phase with striations was formed in the N-free (20-29)Cr alloys, while there was slight formation of ε-phase in the N-containing (20-29)Cr alloys, which disappeared in N-containing 33Cr. The lattice parameter of the γ-phase increased with increasing Cr content (i.e. N content) in the N-containing alloys, although the lattice parameter remained almost the same in the N-free alloys because of the small atomic radius difference between Co and Cr. Compositional analyses by EDS and XRD revealed that in the N-containing alloys Cr and Mo were concentrated in the cell boundary, which became enriched in N, stabilizing the γ-phase. The mechanical properties of the N-free alloys were independent of the Cr content and showed low strength and limited elongation. Strain-induced martensite was formed in all the N-free alloys after tensile testing. On the other hand, the proof strength, ultimate tensile strength, and elongation of the N-containing alloys increased with increasing Cr content (i.e. N content). Since formation of ε-phase after tensile testing was confirmed in the N-containing alloys the deformation mechanism may change from strain-induced martensite transformation to another form, such as twinning or dislocation slip, as the N content increases. Thus the N

  15. High Cycle Fatigue Properties of Die-Cast Magnesium Alloy AZ91D with Addition of Different Concentrations of Cerium

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The effect of addition of different concentrations of Ce on high-cycle fatigue behavior of die-cast magnesium al-loy AZ91D was investigated. Mechanical fatigue tests were conducted at the stress ratio of R = 0.1, and fatigue strength was evaluated using up-and-down loading method. The results show that the grain size of AZ91D alloy is remarkably refined, and the amount of porosity decreases and evenly distributes with the addition of Ce. The fatigue strength of AZ91D alloy at room temperature increases from 96.7 up to 116.3 MPa (1% Ce) and 105.5 MPa (2% Ce), respectively, at the number of cycles to failure, Nf = 1 × 107. The fatigue crack of AZ91D alloy initiates at porosities and inclusions, and propagates along grain boundaries. The fatigue striations on fractured surface appear with Ce addition. The fatigue fracture surface of test specimens shows mixed-fracture characteristics of quasi-cleavage and dimple.

  16. Hybrid Laser-Arc Welding of 10-mm-Thick Cast Martensitic Stainless Steel CA6NM: As-Welded Microstructure and Mechanical Properties

    Science.gov (United States)

    Mirakhorli, Fatemeh; Cao, Xinjin; Pham, Xuan-Tan; Wanjara, Priti; Fihey, Jean-Luc

    2016-07-01

    Cast CA6NM martensitic stainless steel plates, 10 mm in thickness, were welded using hybrid laser-arc welding. The effect of different welding speeds on the as-welded joint integrity was characterized in terms of the weld bead geometry, defects, microstructure, hardness, ultimate tensile strength, and impact energy. Significant defects such as porosity, root humping, underfill, and excessive penetration were observed at a low welding speed (0.5 m/min). However, the underfill depth and excessive penetration in the joints manufactured at welding speeds above 0.75 m/min met the specifications of ISO 12932. Characterization of the as-welded microstructure revealed untempered martensite and residual delta ferrite dispersed at prior-austenite grain boundaries in the fusion zone. In addition, four different heat-affected zones in the weldments were differentiated through hardness mapping and inference from the Fe-Cr-Ni ternary phase diagram. The tensile fracture occurred in the base metal for all the samples and fractographic analysis showed that the crack path is within the martensite matrix, along primary delta ferrite-martensite interfaces and within the primary delta ferrite. Additionally, Charpy impact testing demonstrated slightly higher fracture energy values and deeper dimples on the fracture surface of the welds manufactured at higher welding speeds due to grain refinement and/or lower porosity.

  17. 硬型铸造Ti-Al合金的组织与拉伸性能%Microstructures and Tensile Properties of Ti-Al Based Alloys by Permanent Mold Casting

    Institute of Scientific and Technical Information of China (English)

    李胜; 骆晨; 朱春雷; 张继

    2011-01-01

    试验研究了石墨和铸钢两种硬型铸造Ti-Al合金板片状试样的缺陷、层片间距和室温拉伸性能,并与用陶瓷型壳铸造的Ti-Al合金进行对比.结果表明,采用硬型铸造Ti-Al合金在比较高的冷却速度下凝固的板片状试样无宏观和微观裂纹;与陶瓷型壳铸造的组织相比,硬型铸造Ti-Al合金的板片状试样铸态组织平均层片间距大幅度减小,其中石墨型铸造的减小了近一半;由于硬型铸造Ti-Al合金的板片状试样的层片间距的减小使得其室温拉伸强度有较大幅度的提高,其中石墨型铸造板片试样的层片问距减小了0.35 μm,屈服强度提高了40 MPa.%The properties the casting plate were studied in this paper, such as, the casting defect, lamellar spacing and room temperature tensile properties of Ti-AI based plate by graphite mold and cast-steel mold, and were compared with the Ti-AI based plate by ceramics mold. The experimental results show that there was no macro and micro crack in these permanent mold casting plates at the higher cooling rate during the solidification; the lamellar spacing of permanent mold casting plate was greatly reduced, compared with that of ceramics mold casting plate, and the lamellar spacing of the graphite mold casting plate was reduced approximately one half; the lamellar spacing was decreased so that the tensile properties clearly increased, for example, the lamellar spacing of the graphite mold casting plate was reduced 0.35 \\im, but the yield strength was increased 40 Mpa.

  18. Microstructure modification by La2O3 and its effect on wear resistance properties of as-cast ZL107 alloy

    Institute of Scientific and Technical Information of China (English)

    WAN Diqing

    2010-01-01

    Modification of ZL107 aluminum alloy has been successfully achieved by using La2O3. The different casting parameters, including casting temperature as well as holding time and modifier content, were carried out to investigate the modification effects. The results show that the best modifier content is 1.0 wt.%, and the casting temperature has little effect. In addition, the wear behavior of modified and unmodified ZL107 has been compared. The wear resistance of as-cast ZL107 aluminum alloy can be significantly improved after modification.

  19. IMPACT OF TIME / TEMPERATURE CURING CONDITIONS AND ALUMINATE CONCENTRATIONS ON SALTSTONE PROPERTIES

    Energy Technology Data Exchange (ETDEWEB)

    Harbour, J.; Edwards, T.; Williams, V.

    2009-05-05

    This report addresses the impact of (1) the time and temperature curing conditions (profile) and (2) the impact of higher aluminate concentrations in the decontaminated salt solution on Saltstone processing and performance properties. The results demonstrate that performance properties as well as some of the processing properties of Saltstone are highly sensitive to the conditions of time and temperature under which curing occurs. This sensitivity is in turn dependent on the concentration of aluminate in the salt feed solution. In general, the performance properties and indicators (Young's modulus, compressive strength and total porosity) are reduced when curing is initially carried out under high temperature. However, this reduction in performance properties is dependent on the sequence of temperatures (the time/temperature profile) experienced during the curing process. That is, samples that are subjected to a 1, 2, 3 or 4 day curing time at 60 C followed by final curing at 22 C lead to performance properties that are significantly different than the properties of grouts allowed to cure for 1, 2, 3 or 4 days at 22 C followed by a treatment at 60 C. The performance properties of Saltstone cured in the sequence of higher temperature first are generally less (and in some cases significantly less) than performance properties of Saltstone cured only at 22 C. This loss in performance was shown to be mitigated by increased slag content or cement content in the premix at the expense of fly ash. For the sequence in which the Saltstone is initially cured at 22 C followed by a higher temperature cure, the performance properties can be equal to or greater than the properties observed with curing only at 22 C curing. The results in this report indicate that in order to meaningfully measure and report the performance properties of Saltstone, one has to know the time/temperature profile conditions under which the Saltstone will be cured. This will require thermal modeling

  20. Effect of solution annealing on properties of used reformer centrifugally casted tubes prior to repair by welding

    Directory of Open Access Journals (Sweden)

    B. Mateša

    2014-01-01

    Full Text Available The specimens of damaged tubes, ASTM A297 HK 40, are repaired by welding. Before repairing, solution annealing is used as a procedure for properties restitution. This paper explores the influence of used solution annealing procedure (1 050 şC / 2h on mechanical and micro-structural properties. The emphasis is put on specific procedures at repair by welding.

  1. Advanced Lost Foam Casting Technology

    Energy Technology Data Exchange (ETDEWEB)

    Charles E. Bates; Harry E. Littleton; Don Askeland; Taras Molibog; Jason Hopper; Ben Vatankhah

    2000-11-30

    This report describes the research done under the six tasks to improve the process and make it more functional in an industrial environment. Task 1: Pattern Pyrolysis Products and Pattern Properties Task 2: Coating Quality Control Task 3: Fill and Solidification Code Task 4: Alternate Pattern Materials Task 5: Casting Distortion Task 6: Technology Transfer

  2. High speed twin roll casting of 6061 alloy strips

    OpenAIRE

    T. Haga; Sakaguchi, H.; H. Watari; S. Kumai

    2008-01-01

    Purpose: of this paper is to clear the possibility of high speed roll casting of thin strips of two aluminum alloys:6061 and recycled 6061. Mechanical properties of the roll cast 6061 and recycled 6061 strips were investigated inthe frame of this purpose.Design/methodology/approach: Methods used in the present study were high speed twin roll caster and lowtemperature casting. These methods were used to realize rapid solidification and increase the casting speed.Findings: are that 6061 and rec...

  3. THE WEAR RESISTANCE INCREASE OF CHROMIUM CAST IRON

    Directory of Open Access Journals (Sweden)

    V. M. Ilyushenko

    2016-01-01

    Full Text Available The article presents the results of the tests on the wear resistance of chromium cast irons of different compositions obtained in sand forms. It has been shown that increase of the wear resistance and mechanical properties of the cast iron is possible to obtain using the casting in metal molds. A further increase in wear resistance of parts produced in metal molds is possible by changing the technological parameters of casting and alloying by titanium.

  4. The effect of strontium on the microstructure, porosity and tensile properties of A356-10%B{sub 4}C cast composite

    Energy Technology Data Exchange (ETDEWEB)

    Lashgari, H.R. [Center of Excellence for High Performance Materials, School of Metallurgy and Materials, University of Tehran, Tehran 11365-4563 (Iran, Islamic Republic of); Emamy, M., E-mail: emamy@ut.ac.ir [Center of Excellence for High Performance Materials, School of Metallurgy and Materials, University of Tehran, Tehran 11365-4563 (Iran, Islamic Republic of); Razaghian, A. [Imam Khomeini International University, Qazvin (Iran, Islamic Republic of); Najimi, A.A. [Center of Excellence for High Performance Materials, School of Metallurgy and Materials, University of Tehran, Tehran 11365-4563 (Iran, Islamic Republic of)

    2009-08-20

    This study was undertaken to investigate the effect of different concentrations of strontium (0.05%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5% and 1%) on the microstructure, porosity content and tensile properties of A356-10%B{sub 4}C particulate metal matrix composite. In this work, the matrix alloy and composite were characterized by optical microscope, scanning electron microscope equipped with EDS and XRD. The composite ingots were made by stir casting process. The results showed that the addition of 0.03%Sr strongly modified silicon eutectic phase in A356 monolithic alloy, but 0.5%Sr was needed to complete the modification of A356-10%B{sub 4}C composite. Results also demonstrated that Sr addition increases shrinkage porosity and generates new intermetallics in the microstructure. Further investigations on tensile tests revealed optimum strontium levels for improving tensile properties. In the point of fracture behavior of the composite, modified specimens with 0.2%Sr showed broken B{sub 4}C particles and acceptable cohesion between B{sub 4}C and matrix.

  5. Ductile and Compacted Graphite Iron Casting Skin -- Evaluation, Effect on Fatigue Strength and Elimination

    Science.gov (United States)

    Boonmee, Sarum

    Compacted graphite (CG) iron features a good combination of tensile strength, impact resistance, thermal conductivity and damping capacity. This combination makes CG iron a material of choice for various applications, especially for the automobile industry. The mechanical properties of CG iron listed in the standards (i.e. ASTM) are for machined specimens. However, since most iron castings retain the original casting surface (a.k.a. casting skin), the actual performance of the part could be significantly different from that of the machined specimens. Recent studies have shown the negative effect of the casting skin, but little quantification of its effect on mechanical properties is available. Further, the understanding of its mechanism of formation is at best incomplete. In this research, the effect of the casting skin on mechanical properties in CG and ductile irons (DI) is explored. The differences in tensile and fatigue properties between as-cast and machined samples were quantified and correlated to the casting skin features. It was found that the presence of the casting skin was accountable for 9% reduction of tensile strength and up to 32% reduction of fatigue strength (for CG iron with 40% nodularity). Several mechanisms of the casting skin formation are proposed in this research. The formation of ferritic and pearlitic rims is explained by decarburizing/carburizing reactions at the mold/metal interface. Mg depletion and solidification kinetics effect were identified as the formation mechanisms of the graphite degradation. A 2-D thermal diffusion model was formulated based on Mg depletion theory. The model can be used to predict the casting skin thickness when Mg depletion is the dominant mechanism. Furthermore, using the asymmetric Fe-Gr phase diagram, some instances of casting skin formation were explained based on solidification kinetics theory. The experimental microstructural evidence and the theoretical progress were conducive to the development of

  6. Influence of formwork surface on the orientation of steel fibres within self-compacting concrete and on the mechanical properties of cast structural elements

    DEFF Research Database (Denmark)

    Svec, Oldrich; Zirgulis, Giedrius; Bolander, John E.;

    2014-01-01

    The influences of formwork surface on the final orientation of steel fibres immersed in self-compacting concrete and on the resulting mechanical response of the cast structural elements are investigated. Experimental observations of fibre orientation within cast slabs, obtained via computed tomog...

  7. Study of potential advantages of pre-soaking on the properties of pre-cast concrete made with recycled coarse aggregate

    Directory of Open Access Journals (Sweden)

    Sánchez-Roldán, Z.

    2016-03-01

    Full Text Available Recycled aggregate (RA from construction and demolition waste is traditionally used for the manufacture of concrete for different applications. Due primarily to high water content required by RA, the quality of the concrete is determined by the amount of replacement RA. The aim of this study is to determine if RA pre-soaking enhances the properties of pre-cast concrete for street furniture, with low mechanical and structural requirements, in which 100% of the coarse fraction is replaced. The results of physical and mechanical tests performed on concrete specimens in which the RA was pre-soaked using five different methods applied are compared with a reference concrete sample and a concrete sample made with non-pre-soaked RA. The results show that non-pre-soaked RA offers improved physical-mechanical properties for pre-cast concrete, except for the workability; problems arising from poorer workability could be improved with the use of plasticizers, which can be easily included in the production process.El árido reciclado (AR procedente de residuos de construcción y demolición se utiliza tradicionalmente en la elaboración de hormigón para diferentes aplicaciones. Debido principalmente al mayor contenido en agua requerido por el AR, la calidad del hormigón está determinada por la cantidad de AR reemplazado. El objetivo de este estudio es determinar si el AR premojado mejora las propiedades del hormigón prefabricado para mobiliario urbano, con bajas exigencias mecánicas y estructurales, en el que se sustituye el 100% de la fracción gruesa. Los resultados de los ensayos físicos y mecánicos realizados sobre muestras de hormigón en las cuales el AR se ha premojado usando cinco métodos diferentes se han comparado con una muestra de hormigón de referencia y una muestra de hormigón fabricada con AR no premojado. Los resultados muestran que el AR no premojado proporciona propiedades físico-mecánicas mejoradas en el hormigón prefabricado

  8. Heat treatment of long term serviced Cr – Mo cast steel

    Directory of Open Access Journals (Sweden)

    G. Golanski

    2010-01-01

    Full Text Available The paper presents results of research on the influence of heat treatment on the structure and properties of L20HM cast steel after long term operation at elevated temperature. Investigated cast steel was taken out from an outer frame of a steam turbine serviced for 167 424 hours at the temp. of 535 oC and pressure 12.75 MPa. In post-operating condition the investigated cast steel was characterized by mechanical properties below the required minimum and by high brittleness. Performed research on the influence of austenitizing parameters has revealed that the range of austenitizing temperatures for the examined cast steel: Ac3 + 30 ÷ 60 oC ensures obtaining of a fine austenite grain, homogeneous in size. It has been proved that tempering of bainititc – ferritic structure above 680 ÷ 690 oC causes an increase of impact energy along with a decrease of mechanical properties below the required minimum. Moreover, it has been noticed that applying of under-annealing instead of tempering, after full-annealing, guarantees the required impact energy of KV > 27J, with the mechanical properties similar to those after service.

  9. Abrasive Wear Behavior of High Chromium Cast Iron and Hadfield Steel-- A Comparison

    Institute of Scientific and Technical Information of China (English)

    Mehdi Mazar Atabaki; Sajjad Jafari; Hassan Abdollah-pour

    2012-01-01

    Wear properties of two different crushers used for grinding raw materials of cement industry are compared using pin-on-disk wear test.The wear test was carried out with different loads on a pin.Abrasive wear behavior of two alloys was evaluated by comparing mass loss,wear resistance,microhardness and friction coefficient.The microstructure of the specimens was detected using optical microscope.The results showed that abrasive wear of high chromium cast iron is lower than that of Hadfield steel.Due to the presence of M7C3 carbides on the high chromium cast iron matrix,impact crushers exhibited higher friction coefficient

  10. Assessment of the Low Alloy Cast Steel Inoculation Effects with Chosen Additives

    Directory of Open Access Journals (Sweden)

    D. Bartocha

    2012-04-01

    Full Text Available Structure, and thus the mechanical properties of steel are primarily a function of chemical composition and the solidification process which can be influenced by the application of the inoculation treatment. This effect depends on the modifier used. The article presents the results of studies designed to assess the effects of structural low alloy steel inoculation by selected modifying additives. The study was performed on nine casts modeled with different inoculants, assessment of the procedure impact was based on the macrostructure of made castings. The ratio of surface area equivalent to the axial zone of the crystals and columnar crystals zone was adopted as a measure of the inoculation effect.

  11. Strip Casting of High Performance Structural Alloys

    Institute of Scientific and Technical Information of China (English)

    S S Park; J G Lee; Nack J Kim

    2004-01-01

    There exists a great need for the development of high performance alloys due to increasing demands for energy conservation and environmental protection. Application of strip casting shows a strong potential for the improvement of properties of existing alloys and also for the development of novel alloy systems with superior properties. The present paper reviews our Center's activities in the development of high performance alloys by strip casting. Examples include (1) Al alloys, (2) wrought Mg alloys, and (3) bulk metallic glass (BMG) alloys.

  12. Method for Investigation of Frictional Properties at Impact Loading

    Science.gov (United States)

    Sundin, K. G.; Åhrström, B. O.

    1999-05-01

    In the assessment of lubricant performance and also in various other contact applications it is of importance to know the frictional qualities of a surface. Under quasi-static conditions, normal and frictional forces are measured using force transducers but the task is more difficult when loads are transient. The experimental method presented in this paper is based on the analysis of propagating waves in a beam, due to an impact on the end surface. The impact is oblique and therefore a transverse as well as a normal force is generated. The normal force history is measured from the axial non-dispersive wave using strain gauges. Transverse force and bending moment both generate dispersive flexural waves. From the FFT of two transverse acceleration histories, the frictional force at the end of the rod is evaluated using beam theory. The relation between normal and frictional force histories displays the frictional properties at the impact. Preliminary results are presented.

  13. Criterion for selection the optimal physical and chemical properties of cobalt aluminate powder used in investment casting process

    OpenAIRE

    M. Zielińska; J. Sieniawski; B. Gajecka

    2009-01-01

    The aim of this work was to determine physical and chemical properties of cobalt aluminate (CoAl2O4) modifiers produced by different companies and the influence of different types of modifiers on the grain size of high temperature creep resisting superalloys: Inconel 713C, René 77 and MAR-M 509.The first stage of the research work took over the investigations of physical and chemical properties of cobalt aluminate manufactured by three different companies: Remet, Mason Color and Permedia Lubl...

  14. Studi Eksperimental Pengaruh Model Sistem Saluran Dan Variasi Temperatur Tuang Terhadap Prosentase Porositas, Kekerasan Dan Harga Impact Pada Pengecoran Adc 12 Dengan Metode Lost Foam Casting

    Directory of Open Access Journals (Sweden)

    Restu Yanuar Salam

    2015-03-01

    Full Text Available Metode pengecoran lost foam merupakan metode yang tergolong baru dalam industri pengecoran logam. Pada saat ini belum banyak industri pengecoran logam yang menggunakan metode ini dalam memproduksi benda cor. Sedikitnya industri yang menerapkan metode pengecoran ini, yang mendorong untuk melakukan percobaan pengecoran dengan menggunakan metode lost foam, dengan melakukan perbedaan variasi temperatur tuang dan variasi model sistem saluran. Proses pengecoran dengan metode lost foam ini menggunakan styrofoam sebagai polanya, yang ditanam dalam cetakan yang berisi pasir silika kering (tanpa pengikat kemudian cetakan digetarkan untuk memadatkan pasir. Ketika logam cair dimasukkan ke dalam cetakan, maka styrofoam akan menguap sampai cetakan tersebut terisi penuh oleh logam cair. Dalam penelitian ini, parameter yang digunakan adalah model sistem saluran dan variasi temperatur tuang terhadap kualitas hasil coran, diantaranya kekerasan, harga impact, prosentase porositas dan struktur mikro. Material yang digunakan dalam pengecoran ini adalah ADC (Aluminium Die Casting 12. Parameter pertama yaitu model sistem saluran meliputi saluran samping, saluran bawah, saluran bawah dengan 2 gate dan saluran bawah dengan 3 gate dengan temperatur tuang konstan 700°C. Parameter kedua yaitu variasi perbedaan temperatur tuang antara 700°C, 750°C, 800°C dan 850°C dengan sistem saluran samping. Dari hasil penelitian ini diperoleh bahwa sistem saluran samping memiliki prosentase cacat porositas paling sedikit dibanding sistem saluran lainnya yaitu sebesar 2,7535% dan memiliki harga impact rata-rata paling besar yaitu 0,0275 J/mm2 pada potongan 1 dan 0,0660 J/mm2 pada potongan 2. Variasi temperatur tuang berpengaruh terhadap banyaknya cacat porositas dan harga impact rata-rata. Temperatur tuang 700°C dibanding temperatur tuang yang lain memiliki cacat porositas paling sedikit dan harga impact rata-rata paling besar yaitu 0,0275 J/mm2 pada potongan 1 dan 0,0660 J/mm2

  15. Analysis of the structure of castings made from chromium white cast iron resistant to abrasive wear

    Directory of Open Access Journals (Sweden)

    D. Kopyciński

    2009-10-01

    Full Text Available It has been proved that an addition of boron carbide and disintegrated steel scrap introduced as an inoculant to the chromium white cast iron changes the structure of castings. The said operation increases the number of crystallization nuclei for dendrites of the primary austenite. In this case, the iron particles act as substrates for the nucleation of primary austenite due to a similar crystallographic lattice. The more numerous are the dendrites of primary austenite and the structure more refined and the mechanical properties higher. Castings after B4C inoculation revealed a different structure of fine grained fracture. Primary precipitates of chromium carbide also appeared, reducing the mechanical properties of as-cast parts. Properly established heat treatment regime makes chromium iron castings regain their, originally high, mechanical properties.

  16. Advanced precision expendable pattern casting technology. 1994 Summary report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-05-01

    Casting technology is described. The following areas are reported on: precision pattern production; pattern coating; sand fill and compaction; pattern gating; mechanical properties; and technology transfer efforts.

  17. Asteroid Impact Deflection and Assessment (AIDA) mission - Properties of Impact Ejecta

    Science.gov (United States)

    Hamilton, Douglas P.; Fahnestock, Eugene G.; Schwartz, Stephen R.; Murdoch, Naomi; Asphaug, Erik; Cheng, Andrew F.; Housen, Kevin R.; Michel, Patrick; Miller, Paul L.; Stickle, Angela; Tancredi, Gonzalo; Vincent, Jean-Baptiste; Wuennemann, Kai; Yu, Yang; AIDA Impact Simulation Working Group

    2016-10-01

    The Asteroid Impact Deflection and Assessment (AIDA) mission is composed of NASA's Double Asteroid Redirection Test (DART) mission and ESA's Asteroid Impact Monitor (AIM) rendezvous mission. The DART spacecraft is designed to impact the small satellite of near-Earth asteroid 65803 Didymos in October 2022, while the in-situ AIM spacecraft observes. AIDA's Modeling and Simulation of Impact Outcomes Working Group is tasked with investigating properties of the debris ejected from the impact. The orbital evolution of this ejecta has important implications for observations that the AIM spacecraft will take as well as for the safety of the spacecraft itself. Ejecta properties including particle sizes, bulk densities, and velocities all depend on the poorly-known physical properties of Didymos' moon. The moon's density, internal strength, and especially its porosity have a strong effect on all ejecta properties. Making a range of assumptions, we perform a suite of numerical simulations to determine the fate of the ejected material; we will use simulation predictions to optimize AIM observations and safety. Ultimately, combining AIM's observations of the ejecta with detailed numerical simulations will help constrain key satellite parameters.We use distinct types of numerical tools to explore ejecta properties based on additional target parameters (different forms of friction, cohesion), e.g., the shock physics code iSALE, smoothed particle hydrodynamics codes, and the granular code PKDGRAV. Given the large discrepancy between the 6 km/s impact speed of DART and the moon's 6 cm/s escape speed, a great challenge will be to determine properties of the low-speed ejecta. Very low-speed material relevant to the safety of the AIM spacecraft and its ability to conduct its observations may loft from the crater at late stages of the impact process, or from other locations far from the impact site due to seismic energy propagation. The manner in which seismic waves manifests in

  18. Optimization of the Chemical Composition of Cast Iron Used for Casting Ball Bearing Grinding Disks

    Institute of Scientific and Technical Information of China (English)

    Aurel Crisan; Sorin Ion; Munteanu; Ioan Ciobanu; Iulian Riposan

    2008-01-01

    The chemical composition of cast iron used for casting ball bearing machining disks was varied to optimize the properties such as castability, hardenability, and durability in ball machining. The cast iron characteristics were most strongly dependent on the Ni content and the carbon saturation degree, So. This paper describes the types of test specimens, the working conditions, and the experimental results. The in-crease of the degree of carbon saturation reduces the tendency to form shrinkholes in the castings. The de-crease in the Ni content negatively affects the final hardening treatment. A way to control solidification de-fects in cast iron, by reducing the Ni content, has been verified on cast disks.

  19. Soldier caste influences on candidate primer pheromone levels and juvenile hormone-dependent caste differentiation in workers of the termite Reticulitermes flavipes

    Science.gov (United States)

    Caste systems and the division of labor they make possible are common underlying features of all social insects. Multiple extrinsic factors have been shown to impact caste differentiation; for example, primer pheromones are chemical signaling molecules produced by certain castes that impact developm...

  20. Microstructural Evolution and Mechanical Properties of Simulated Heat-Affected Zones in Cast Precipitation-Hardened Stainless Steels 17-4 and 13-8+Mo

    Science.gov (United States)

    Hamlin, Robert J.; DuPont, John N.

    2016-11-01

    Cast precipitation-hardened (PH) stainless steels 17-4 and 13-8+Mo are used in applications that require a combination of high strength and moderate corrosion resistance. Many such applications require fabrication and/or casting repair by fusion welding. The purpose of this work is to develop an understanding of microstructural evolution and resultant mechanical properties of these materials when subjected to weld thermal cycles. Samples of each material were subjected to heat-affected zone (HAZ) thermal cycles in the solution-treated and aged condition (S-A-W condition) and solution-treated condition with a postweld thermal cycle age (S-W-A condition). Dilatometry was used to establish the onset of various phase transformation temperatures. Light optical microscopy (LOM), scanning electron microscopy (SEM), and energy dispersive spectrometry (EDS) were used to characterize the microstructures, and comparisons were made to gas metal arc welds that were heat treated in the same conditions. Tensile testing was also performed. MatCalc thermodynamic and kinetic modeling software was used to predict the evolution of copper (Cu)-rich body center cubic precipitates in 17-4 and β-NiAl precipitates in 13-8+Mo. The yield strength was lower in the simulated HAZ samples of both materials prepared in the S-A-W condition when compared to their respective base metals. Samples prepared in the S-W-A condition had higher and more uniform yield strengths for both materials. Significant changes were observed in the matrix microstructure of various HAZ regions depending on the peak temperature, and these microstructural changes were interpreted with the aid of dilatometry results, LOM, SEM, and EDS. Despite these significant changes to the matrix microstructure, the changes in mechanical properties appear to be governed primarily by the precipitation behavior. The decrease in strength in the HAZ samples prepared in the S-A-W condition was attributed to the dissolution of precipitates

  1. Investigations of Protective Coatings for Castings of High-manganese Cast Steels

    Directory of Open Access Journals (Sweden)

    M. Holtzer

    2013-01-01

    Full Text Available When cast steel castings are made in moulding sands on matrices of high-silica sand, which has a low fire resistance the problem of theso-called chemical penetration is distinctly visible. Whereas this effect appears to a small degree only when moulding sand matrices are of chromite, zircon or olivine sands. Therefore in case of making castings of high-manganese cast steel (e.g. Hadfield steel sands not containing free silica should be applied (e.g. olivine sand or in case of a high-silica matrix protective coatings for moulds and cores should be used. Two protective coatings, magnesite alcoholic (marked as coating 1 and coating 2 originated from different producers and intended for moulds for castings of the Hadfield steel, were selected for investigations. Examinations of the basic properties were performed for these coatings: viscosity, thermal analysis, sedimentation properties, wear resistance. In order to estimate the effectiveness of protective coatings the experimental castings were prepared. When applying coating 1, the surface quality of the casting was worse and traces of interaction between the casting material (cast steel and the coating were seen. When protective coating 2 was used none interactions were seen and the surface quality was better.

  2. High-strength cast irons used for manufacturing parts of vaz passenger cars

    Science.gov (United States)

    Kitaigora, N. I.

    1996-10-01

    Methods for solving problems arising in the production of high-strength cast iron with stable properties and structure are considered. Results of introduction of new grades of high-strength cast iron instead of malleable cast iron and camshaft cast iron in the Volzhskii Automobile Plant are described.

  3. Preparation of cast aluminum alloy-mica particle composites

    Science.gov (United States)

    Deonath, MR.; Bhat, R. T.; Rohatgi, P. K.

    1980-01-01

    A method for making aluminum-mica particle composites is presented in which mica particles are stirred in molten aluminum alloys followed by casting in permanent molds. Magnesium is added either as an alloying element or in the form of pieces to the surface of the alloy melts to disperse up to 3 wt% mica powders in the melts and to obtain high recoveries of mica in the castings. The mechanical properties of the aluminum alloy-mica composite decrease with increasing mica content; however, even at 2.2% it has a tensile strength of 14.22 kg/sq mm with 1.1% elongation, a compression strength of 42.61 kg/sq mm, and an impact strength of 0.30 kgm/sq cm. Cryogenic and self-lubricating bearing are mentioned applications.

  4. HA/nylon 6,6 porous scaffolds fabricated by salt-leaching/solvent casting technique: effect of nano-sized filler content on scaffold properties.

    Science.gov (United States)

    Mehrabanian, Mehran; Nasr-Esfahani, Mojtaba

    2011-01-01

    Nanohydroxyapatite (n-HA)/nylon 6,6 composite scaffolds were produced by means of the salt-leaching/solvent casting technique. NaCl with a distinct range size was used with the aim of optimizing the pore network. Composite powders with different n-HA contents (40%, 60%) for scaffold fabrication were synthesized and tested. The composite scaffolds thus obtained were characterized for their microstructure, mechanical stability and strength, and bioactivity. The microstructure of the composite scaffolds possessed a well-developed interconnected porosity with approximate optimal pore size ranging from 200 to 500 μm, ideal for bone regeneration and vascularization. The mechanical properties of the composite scaffolds were evaluated by compressive strength and modulus tests, and the results confirmed their similarity to cortical bone. To characterize bioactivity, the composite scaffolds were immersed in simulated body fluid for different lengths of time and results monitored by scanning electron microscopy and energy dispersive X-ray microanalysis to determine formation of an apatite layer on the scaffold surface.

  5. The melting diagram of the Ti-corner of the Ti-Zr-Si system and mechanical properties of as-cast compositions

    Energy Technology Data Exchange (ETDEWEB)

    Bulanova, M.; Firstov, S.; Gornaya, I.; Miracle, D

    2004-12-14

    Phase equilibria in the Ti-corner of the Ti-Zr-Si system were studied by the methods of metallography, differential thermal analysis, X-ray and microprobe analyses of as-cast samples. The results are given in the way of the melting diagram and of polythermal sections at 10 and 20 at.% Si. At 1300 deg. C invariant four-phase equilibrium of eutectic type L{r_reversible}<{beta}-Ti>({beta})+(Z)+<(Ti,Zr){sub 2}Si> (S2) was shown to occur in the concentration interval studied. The location of the eutectic point E was determined to take place at {approx}78Ti-11Zr-11Si. The ternary compound S2 formed from the melt by peritectic reaction L+Z{yields}S2. Microhardness of the primary silicide grains and of eutectics microconstituents has shown that zirconium additions decrease the strength of the Z-phase and of the {beta}+Z eutectic, while they do not change the strength of the S2-silicide and of the {beta}+S2 eutectic. Based on the results of hot hardness measurements, below 550 deg. C the potential for attractive high-temperature structural properties is controlled by refinement of the microstructure, while above this temperature the {alpha}{r_reversible}{beta} transformation temperature of Ti limits the application.

  6. Effect of Multiple-Pass Friction Stir Processing Overlapping on Microstructure and Mechanical Properties of As-Cast NiAl Bronze

    Science.gov (United States)

    Ni, D. R.; Xue, P.; Ma, Z. Y.

    2011-08-01

    As-cast Cu-9Al-4.5Ni-4Fe NiAl bronze alloy (NAB) was subjected to multiple-pass friction stir processing (FSP) with a 50 pct overlap. After FSP, the coarse microstructure of the base metal (BM) was transformed to defect-free material with fine microstructure. While the torchlike patterns in the stir zone (SZ) and the uplifted grains in the transitional zones (TZs) between two passes were observed in the multiple-pass FSP region, no grain coarsening was found in the remnant zone of the previous SZ after subsequent FSP pass. The hardness value of the FSP materials was higher than that of the BM and was homogeneously distributed throughout the entire multiple-pass FSP region. The FSP materials showed greatly improved tensile properties compared to the BM, and the TZs showed similar tensile strength and ductility to the single-pass FSP materials. The BM broke in a mixture mode of brittle cleavage and microvoid coalescence fracture, whereas the FSP and TZ samples failed in the latter fracture mode. The results showed that the multiple-pass overlapping (MPO) FSP was feasible to modify the microstructure of large-sized plate of the NAB.

  7. Effect of Stirring Velocity in Micro Fused-Casting for Metal on Microstructure and Mechanical Properties of A356 Aluminum Alloy Slurry

    Institute of Scientific and Technical Information of China (English)

    LUO Xiaoqiang; LI Zhengyang; SHI Xiaojiao; YAN Qingzhi

    2016-01-01

    A novel micro fused-casting for metal (MFCM) process for producing A356 aluminum alloy slurry was proposed. MFCM means that the reifned metal slurry is pressed out from the outlet of bottom of crucible to the horizontal movable plate. With the aid of 3D manufacturing software, the melt is solidiifed and formed layer by layer. The stirring could keep the ingredients and the heat diffusion of metal slurry uniform in the crucible due to the shear force breaking down the dendrite arms. The solidus and liquidus temperatures of A356 alloy were 559.2 and 626.3℃, respectively, which were measured by differential scanning calorimetry (DSC). Effect of different stirring velocities of MFCM on the microstructure and mechanical properties of A356 slurry was investigated with the pouring temperature controlled at 620℃. The microstructure and mechanical performance were the best when the stirring velocity was 1 200 r/min in MFCM. The microstructures of the A356 aluminum alloy slurry were mainly composed of ifne spherical or rose grains. The average roundness and average grain size reached 2.2 and 41 µm and the tensile strength of A356 alloy slurry reached 207.8 MPa, while the average vickers hardness was 81.1 HV.

  8. Characterization of Triaxial Braided Composite Material Properties for Impact Simulation

    Science.gov (United States)

    Roberts, Gary D.; Goldberg, Robert K.; Biniendak, Wieslaw K.; Arnold, William A.; Littell, Justin D.; Kohlman, Lee W.

    2009-01-01

    The reliability of impact simulations for aircraft components made with triaxial braided carbon fiber composites is currently limited by inadequate material property data and lack of validated material models for analysis. Improvements to standard quasi-static test methods are needed to account for the large unit cell size and localized damage within the unit cell. The deformation and damage of a triaxial braided composite material was examined using standard quasi-static in-plane tension, compression, and shear tests. Some modifications to standard test specimen geometries are suggested, and methods for measuring the local strain at the onset of failure within the braid unit cell are presented. Deformation and damage at higher strain rates is examined using ballistic impact tests on 61- by 61- by 3.2-mm (24- by 24- by 0.125-in.) composite panels. Digital image correlation techniques were used to examine full-field deformation and damage during both quasi-static and impact tests. An impact analysis method is presented that utilizes both local and global deformation and failure information from the quasi-static tests as input for impact simulations. Improvements that are needed in test and analysis methods for better predictive capability are examined.

  9. Analysis of Dynamic Properties of Piezoelectric Structure under Impact Load

    Directory of Open Access Journals (Sweden)

    Taotao Zhang

    2015-10-01

    Full Text Available An analytical model of the dynamic properties is established for a piezoelectric structure under impact load, without considering noise and perturbations in this paper. Based on the general theory of piezo-elasticity and impact mechanics, the theoretical solutions of the mechanical and electrical fields of the smart structure are obtained with the standing and traveling wave methods, respectively. The comparisons between the two methods have shown that the standing wave method is better for studying long-time response after an impact load. In addition, good agreements are found between the theoretical and the numerical results. To simulate the impact load, both triangle and step pulse loads are used and comparisons are given. Furthermore, the influence of several parameters is discussed so as to provide some advices for practical use. It can be seen that the proposed analytical model would benefit, to some extent, the design and application (especially the airport runway of the related smart devices by taking into account their impact load performance.

  10. The influence of Cerafiber 10 ceramic fibre on strength properties of moulding material for investment casting technology

    Directory of Open Access Journals (Sweden)

    M. Nadolski

    2009-07-01

    Full Text Available The presented investigations have been aimed to determine strength properties of shell ceramic moulds produced on the basis of silica sol with the matrix composed of MK75 silica flour and Cerafiber 10 aluminosilicate ceramic fibre, the chemical composition of the latter being 56% SiO2 and 44% Al2O3. The sample material has been obtained by multi-layer spraying of ceramic slurry onto the pattern sets. The achieved results, concerning strength properties revealed during the controlled bending test performed by means of the four-point deflectometer, have been compared with the presented elsewhere results [16-19] for moulding material with grain or grain-fibre matrix, where TC E08 fibre produced by Thermal Ceramics (i.e. Kaowool HP-50-E-08 fibre has been applied as a matrix component.

  11. LLNL casting technology

    Science.gov (United States)

    Shapiro, A. B.; Comfort, W. J., III

    1994-01-01

    Competition to produce cast parts of higher quality, lower rejection rate, and lower cost is a fundamental factor in the global economy. To gain an edge on foreign competitors, the US casting industry must cut manufacturing costs and reduce the time from design to market. Casting research and development (R&D) are the key to increasing US competiveness in the casting arena. Lawrence Livermore National Laboratory (LLNL) is the home of a wide range of R&D projects that push the boundaries of state-of-the art casting. LLNL casting expertise and technology include: casting modeling research and development, including numerical simulation of fluid flow, heat transfer, reaction/solidification kinetics, and part distortion with residual stresses; special facilities to cast toxic material; extensive experience casting metals and nonmetals; advanced measurement and instrumentation systems. Department of Energy (DOE) funding provides the leverage for LLNL to collaborate with industrial partners to share this advanced casting expertise and technology. At the same time, collaboration with industrial partners provides LLNL technologists with broader insights into casting industry issues, casting process data, and the collective experience of industry experts. Casting R&D is also an excellent example of dual-use technology; it is the cornerstone for increasing US industrial competitiveness and minimizing waste nuclear material in weapon component production. Annual funding for casting projects at LLNL is $10M, which represents 1% of the total LLNL budget. Metal casting accounts for about 80% of the funding. Funding is nearly equally divided between development directed toward US industrial competitiveness and weapon component casting.

  12. Microstructure and magnetic properties of Fe-Co-Nd-Y-B alloys obtained by suction casting method

    Institute of Scientific and Technical Information of China (English)

    J.Olszewski; J.Zbroszczyk; M.Hasiak; J.Kaleta; M.Nabia(l)ek; P.Bragiel; K.Sobczyk; W.Ciurzy(n)ska; J.(S)wierczek; A.(L)ukiewska

    2009-01-01

    The phase composition,magnetic properties i.e.coercivity and the magnetic polarization at room temperature for the bulk Fe67Co5Nd3Y6B19 and Fe64Co5Nd6Y6B19 alloys were studied.The bulk amorphous Fe67Co5Nd3Y6B19 alloy,inhomogeneous in the as-quenched state,crystallized after annealing at 948 K for 0.5 h and consisted of Nd2Fel4B-type,Fe2B and paramagnetic phases.The rapidly solidified Fe67Co5Nd3Y6B19 alloy contained the Nd2Fe14B-type and paramagnetic phases.The annealing of the bulk Fe67Co5Nd3Y6B19 alloy at 948 K for 0.5 h led to hard magnetic properties.However,the bulk Fe67Co5Nd3Y6B19 alloy exhibited good hard magnetic properties directly after preparation.

  13. Effects of Pressure Field on Structure and Properties of Loot Foam Casting ZL101 Alloy%压力场对ZL101铝合金消失模铸造性能的影响

    Institute of Scientific and Technical Information of China (English)

    唐波; 樊自田; 赵忠; 潘迪; 成平

    2009-01-01

    采用自行研制的压力凝固试验装置,研究了ZL101铝合金消失模铸造过程中,不同的压力和加压速率对铸件性能的影响.试验结果表明,随着外加压力的增加.铸件的密度和力学性能逐步提高,孔隙率显著降低,当外加压力达到0.5MPa以上时,ZL101消失模铸件的力学性能提高趋缓;加压时,不同的加压速率对消失模铸件的密度及性能影响很大,当加压速率为0.003~0.030 MPa/s时,铝合金消失模铸件性能较好;由于在压力下凝固,ZL101铝合金消失模铸件针孔等缺陷减少、密度提高,铸件耐腐蚀性进一步提高.%We have developed a set of pressurization solidification experimental apparatus to examine the effects of varied pressures "and pressurization rate on mechanical properties of lost foam casting ZL101 alu-minum alloy components. The results show that with increasing in applied pressure, the density and me-chanical properties of the lost foam casting ZL101 al-loy components are improved gradually, and porosity rate in the castings is greatly decreased, meanwhile, the mechanical properties of the castings exhibit slightly increasing tendency. With a fixed pressure, the density and properties of the casting are closely re-lated to the pressurization rates. The lost foam casting ZL101 alloy components exhibit desirable performance at pressurization rate of 0. 003 MPa~0. 03 MPa. In addition, corrosion resistance of the alloy components is further improved as a result of the increase of densi-ty and decrease of pin-hole defects in the components at pressurization solidification.

  14. Model castings with composite surface layer - application

    Directory of Open Access Journals (Sweden)

    J. Szajnar

    2008-10-01

    Full Text Available The paper presents a method of usable properties of surface layers improvement of cast carbon steel 200–450, by put directly in foundingprocess a composite surface layer on the basis of Fe-Cr-C alloy. Technology of composite surface layer guarantee mainly increase inhardness and aberasive wear resistance of cast steel castings on machine elements. This technology can be competition for generallyapplied welding technology (surfacing by welding and thermal spraying. In range of studies was made cast steel test castings withcomposite surface layer, which usability for industrial applications was estimated by criterion of hardness and aberasive wear resistance of type metal-mineral and quality of joint cast steel – (Fe-Cr-C. Based on conducted studies a thesis, that composite surface layer arise from liquid state, was formulated. Moreover, possible is control of composite layer thickness and its hardness by suitable selection of parameters i.e. thickness of insert, pouring temperature and solidification modulus of casting. Possibility of technology application of composite surface layer in manufacture of cast steel slide bush for combined cutter loader is presented.

  15. Improved Life of Die Casting Dies of H13 Steel by Attaining Improved Mechanical Properties and Distortion Control During Heat Treatment

    Energy Technology Data Exchange (ETDEWEB)

    J. F. Wallace; D. Schwam

    1998-10-01

    The ultimate goal of this project is to increase die casting die life by using fast enough quenching rates to obtain good toughness and fatigue resistance in premium grade H-13 steel dies. The main tasks of the project were to compile a database on physical and mechanical properties of H-13; conduct gas quenching experiments to determine cooling rates of dies in difference vacuum furnaces; measure the as-quenched distortion of dies and the residual stresses; generate finite element analysis models to predict cooling rates, distortion, and residual stress of gas quenched dies; and establish rules and create PC-based expert system for prediction of cooling rates, distortion, and residual stress in vacuum/gas quenched H-13 dies. Cooling curves during gas quenching of H-13 blocks and die shapes have been measured under a variety of gas pressure. Dimensional changes caused by the gas quenching processes have been determined by accurate mapping of all surfaces with coordinate measuring machines before and after the quench. Residual stresses were determined by the ASTM E837 hole-drilling strain gage method. To facilitate the computer modeling work, a comprehensive database of H-13 mechanical and physical properties has been compiled. Finite element analysis of the heat treated shapes has been conducted using the TRAST/ABAQUS codes. There is a good fit between the predicted and measured distortion contours. However, the magnitude of the predicted distortion and residual stresses does not match well the measured values. Further fine tuning of the model is required before it can be used to predict distortion and residual stress in a quantitative manner. This last step is a prerequisite to generating rules for a reliable expert system.

  16. Effect of Zn on the microstructure and mechanical properties of as-cast Mg–7Gd–3Y–1Nd–0.5Zr alloy

    Energy Technology Data Exchange (ETDEWEB)

    Li, M.; Zhang, K., E-mail: zhkui@grinm.com; Li, X.G.; Yuan, J.W.; Li, Y.J.; Ma, M.L.; Shi, G.L.; Li, T.; Liu, J.B.

    2015-06-25

    The microstructure and mechanical properties of as-cast Mg–7Gd–3Y–1Nd–xZn–0.5Zr (x=0, 0.5, 1 and 2 wt%) alloys have been investigated by optical microscopy (OM), scanning electron microscopy equipped with energy dispersive spectrum, transmission electron microscopy (TEM), X-ray diffraction and tensile tests at room temperature (RT). Experimental results reveal that the microstructure of the alloy without Zn contains α-Mg and Mg{sub 5}RE phase, the microstructure of the alloy with 0.5% Zn consists of α-Mg, (Mg, Zn){sub 3}RE phase, Mg{sub 5}(RE, Zn) phase and stacking fault. The addition of 1% and 2% Zn results in the disappearance of the Mg{sub 5}(RE, Zn) phase, but the stacking fault can be seen more clearly. Moreover, a new block-like long period stacking ordered (LPSO) phase is observed in grain boundaries with increasing Zn content up to 2%. TEM analyses indicate that the Mg{sub 5}RE, (Mg, Zn){sub 3}RE and Mg{sub 5}(RE, Zn) phases have a face-centered cubic (f.c.c.) structure with lattice constants of 2.22 nm, 0.73 nm and 2.23 nm, respectively. The new block-like LPSO phase belongs to 10H-type. The tensile tests at RT exhibit that the alloy containing 1% Zn shows the optimal mechanical properties and the ultimate tensile strength (UTS), yield strength (YS) and elongation are 187 MPa, 145 MPa and 3.1%, respectively. As indicated by fracture analyses, the fracture modes of the alloys with 0% and 0.5% Zn are typically intercrystalline fracture, whereas both intercrystalline and transcrystalline fractures are observed in the alloys with 1% and 2% Zn.

  17. Effect of adding nano-titanium dioxide on the microstructure, mechanical properties and in vitro bioactivity of a freeze cast merwinite scaffold.

    Science.gov (United States)

    Nezafati, Nader; Hafezi, Masoud; Zamanian, Ali; Naserirad, Mandana

    2015-01-01

    In the present research, merwinite (M) scaffolds with and without nano-titanium dioxide (titania) were synthesized by water-based freeze casting method. Two different amounts (7.5 and 10 wt%) of n-TiO2 were added to M scaffolds. They were sintered at temperature of 1573.15°K and at cooling rate of 4°K/min. The changes in physical and mechanical properties were investigated. The results showed that although M and M containing 7.5 wt% n-TiO2 (MT7.5) scaffolds had approximately the same microstructures in terms of pore size and wall thickness, these factors were different for sample MT10. In overall, the porosity, volume and linear shrinkage were decreased by adding different weight ratios of n-TiO2 into the M structure. According to the obtained mechanical results, the optimum mechanical performance was related to the sample MT7.5 (E = 51 MPa and σ = 2 MPa) with respect to the other samples, i.e.: M (E = 47 MPa and σ = 1.8 MPa) and MT10 (E = 32 MPa and σ = 1.4 MPa). The acellular in vitro bioactivity experiment confirmed apatite formation on the surfaces of all samples for various periods of soaking time. Based on cell study, the sample which possessed favorable mechanical behavior (MT7.5) supported attachment and proliferation of osteoblastic cells. These results revealed that the MT7.5 scaffold with improved mechanical and biological properties could have a potential to be used in bone substitute.

  18. Colour Metallography of Cast Iron - Chapter 3: Spheroidal Graphite Cast Iron (Ⅰ

    Directory of Open Access Journals (Sweden)

    Zhou Jiyang

    2010-02-01

    Full Text Available Cast iron, as a traditional metal material, has advantages of low total cost, good castability and machinability, good wear resistance and low notch sensitivity, and is still facing tough challenge in quality, property and variety of types etc. Experts and engineers studying and producing iron castings all around world extremely concern this serious challenge. Over more than 30 years, a great of research work has been carried out on how to further improve its property, expand its application and combine cast iron technology with some hi-techs (for example, computer technology. Nevertheless, cast iron is a multi-element and multi-phase alloy and has complex and variety of structures and still has great development potential in structure and property. For further studying and developing cast iron, theoretical research work is important promise, and the study on solidification process and control mechanism of graphite morphology is fundamental for improving property of cast iron and developing new type of cast iron. Metallography of cast iron normally includes two sections: liquid phase transformation and solid phase transformation. The book, Colour Metallography of Cast Iron, uses colour metallography technique to study solidification structures of cast irons: graphite, carbides, austenite and eutectics; and focuses on solidification processes. With progress of modern solidification theory, the control of material solidification process becomes important measure for improving traditional materials and developing new materials. Solidification structure not only influences mechanical and physical properties of cast iron, but also affects its internal quality. The book uses a large amount of colour photos to describe the formation of solidification structures and their relations. Crystallization phenomena, which cannot be displayed with traditional metallography, are presented and more phase transformation information is obtained from these colour

  19. Impact of biocrust succession on water retention and repellency on open-cast lignite mining sites under reclamation in Lower Lusatia, NE-Germany

    Science.gov (United States)

    Gypser, Stella; Fischer, Thomas; Lange, Philipp; Veste, Maik

    2016-04-01

    Mining activities can strongly affect ecosystem properties by destruction of naturally developed soils and removal of vegetation. The unstructured substrates show high bulk densities, compaction, low water infiltration rates, reduced water holding capacities and higher susceptibility to wind and water erosion. In the initial stage of the ecosystem development, the post-mining sites are open areas without or with a low cover of higher vegetation. It is well-known that biocrusts are able to colonize the soil surface under such extreme conditions without human support and affect soil hydrological processes such as water infiltration, run-off or re-distribution. Investigations were conducted on two former lignite open-cast mining sites, an artificial sand dune on the reclaimed watershed Welzow "Neuer Lugteich" and a reforestation area in Schlabendorf (Brandenburg, north-east Germany). The aim was to relate the hydrological characteristics of the topsoil to successional stages of biological soil crusts on reclaimed soils and their influence on repellency index and water holding capacity compared to pure mining substrate. Our study emphasized the influence of changing successional stages and species composition of biological soil crusts, forming a small-scale crust pattern, on water repellency and retention on sandy soils in temperate climate. Different successional stages of soil crusts were identified from initial scattered green algae crusts, dominated by Zygogonium spec. and Ulothrix spec., and more developed soil crusts containing mosses such as Ceratodon purpureus and Polytrichum piliferum. Lichens of the Genus Cladonia were more pronouncedly contributed to biocrusts at later and mature stages of development. The repellency index on the one hand increased due to the cross-linking of sand particles by the filamentous green algae Zygogonium spec. which resulted in clogging of pores, and on the other hand decreased with the occurrence of moss plants due to absorption

  20. Microstructure and Properties of Solid-Liquid Composite Cast Hammer%固-液复合铸造锤头的组织与性能

    Institute of Scientific and Technical Information of China (English)

    程巨强; 弥国华; 李梦; 刘志学

    2014-01-01

    研究高铬铸铁-碳钢固-液复合铸造锤头的组织及硬度分布特征。结果表明,固-液复合铸造高铬铸铁锤头部分具有较高的硬度,远离复合面高铬铸铁硬度增加,碳钢硬度降低。远离复合面高铬铸铁组织为M7C3型碳化物+回火马氏体+残余奥氏体,固-液复合铸造高铬铸铁组织中碳化物有定向分布的趋势,有利于提高锤头的耐磨性;远离复合面碳钢部分的组织为珠光体和较多的铁素体,复合面附近碳钢组织珠光体数量明显增加,铁素体数量明显减小,高铬铸铁中的碳通过复合界面向碳钢进行扩散。%It's a study on microstructure and hardness distribution characteristics of the solid-liquid composite cast hammer of high chromium cast iron and carbon steel casting. The experimental results have shown that high chromium cast iron of solid-liquid composite cast hammer has better hardness. Far away from composite surface, the hardness of high chromium cast iron hammer increased while that of carbon steel casting decreased and the microstructure was M7C3 type carbide+tempered martensite+residual austenite, and the carbide of solid-liquid composite high chromium cast iron hammer showed a trend of directional distribution propitious to an improved wear resistance. Far away from composite surface, the hardness of cast steel hammer decreased and with microstructure of pearlite and more ferrite. The number of pearlite significant increased and ferrite significant decreased near the composite surface and carbon in high chromium cast iron diffused from composite interface to carbon cast steel.

  1. Impact Behavior of A356 Foundry Alloys in the Presence of Trace Elements Ni and V

    Science.gov (United States)

    Casari, Daniele; Ludwig, Thomas H.; Merlin, Mattia; Arnberg, Lars; Garagnani, Gian Luca

    2015-02-01

    In the present work, the impact behavior of unmodified A356 alloys with the addition of Ni or V in as-cast and T6 heat-treated conditions was assessed. Charpy V-notched specimens obtained from sand and permanent mold casting showed low total absorbed energy average values ( W t permanent mold cast alloys due to the locally finer microstructure. Concurrent mechanisms related to the chemical composition, solidification conditions and heat treatment were found to control the impact properties of the alloys. While the trace element Ni exerted only minor effects on the impact toughness of the A356 alloy, V had a strong influence: (i) V-containing sand cast alloys absorbed slightly higher impact energies compared to the corresponding A356 base alloys; (ii) in the permanent mold cast alloys, V in solid solution led to a considerable loss of ductility, which in turn decreased the total absorbed energy.

  2. Recent development of ductile cast iron production technology in China

    Institute of Scientific and Technical Information of China (English)

    Cai Qizhou; Wei Bokang

    2008-01-01

    Recent progress in the production and technology of ductile cast iron castings in China is reviewed.The manufacture and process control of as-cast ductile iron are discussed.The microstructure.properties and application of partial austenitization normalizing ductile iron and austempered duclile iron(ADI)are briefly depicted.The new development of duclile iron production techniques,such as cored-wire injection(wire-feeding nodularization)process,tundish cover ladle nodularizing process,horizontal continuous casting,and EPC process (lost foam)for ductile iron castings,etc.,are summarized.

  3. Recent development of ductile cast iron production technology in China

    Directory of Open Access Journals (Sweden)

    Cai Qizhou

    2008-05-01

    Full Text Available Recent progress in the production and technology of ductile cast iron castings in China is reviewed. The manufacture and process control of as-cast ductile iron are discussed. The microstructure, properties and application of partial austenitization normalizing ductile iron and austempered ductile iron (ADI are briefl y depicted. The new development of ductile iron production techniques, such as cored-wire injection (wire-feeding nodularization process, tundish cover ladle nodularizing process, horizontal continuous casting, and EPC process (lost foam for ductile iron castings, etc., are summarized.

  4. Structural, morphological and optical properties of PEDOT:PSS/QDs nano-composite films prepared by spin-casting

    Science.gov (United States)

    Najeeb, Mansoor Ani; Abdullah, Shahino Mah; Aziz, Fakhra; Ahmad, Zubair; Rafique, Saqib; Wageh, S.; Al-Ghamdi, Ahmed A.; Sulaiman, Khaulah; Touati, Farid; Shakoor, R. A.; Al-Thani, N. J.

    2016-09-01

    This paper describes the structural, morphological and optical properties of the nano-composite of poly (3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) and quantum dots (QDs). The ZnSe and CdSe QDs have been synthesized, with the aid of Mercaptoacetic acid (MAA), by a colloidal method with an average size of ~5 to 7 nm. QDs have been embedded in PEDOT:PSS using a simple solution processing approach and has been deposited as thin films by spin coating technique. The QDs embedded PEDOT:PSS enhances the light absorption spectra of samples, prominently in terms of absorption intensity which may consequently improve sensitivity of the optoelectronic devices.

  5. Effect of process parameters on properties of Al-Si alloys cast by Rapid Slurry Formation (RSF) technique

    Science.gov (United States)

    Ratke, L.; Sharma, A.; Kohli, D.

    2012-01-01

    Rapid slurry formation is a semi-solid metal forming technique, which is based on a so-called solid enthalpy exchange material (EEM). It is a fascinating technology offering the opportunity to manufacture net-shaped metal components of complex geometry in a single forming operation. At the same time, high mechanical properties can be achieved due to the unique microstructure and flow behaviour. The major process parameters used in the RSF process are rotation speed of the EEM, melt superheat, amount of EEM added (determining fs), and holding time. The process parameters can be well controlled with clear effects on the microstructure. There is a lack of theoretical modelling of the morphological evolution in these two-phase slurries.

  6. Impacts of land leveling on lowland soil physical properties

    Directory of Open Access Journals (Sweden)

    José Maria Barbat Parfitt

    2014-02-01

    Full Text Available The practice of land leveling alters the soil surface to create a uniform slope to improve land conditions for the application of all agricultural practices. The aims of this study were to evaluate the impacts of land leveling through the magnitudes, variances and spatial distributions of selected soil physical properties of a lowland area in the State of Rio Grande do Sul, Brazil; the relationships between the magnitude of cuts and/or fills and soil physical properties after the leveling process; and evaluation of the effect of leveling on the spatial distribution of the top of the B horizon in relation to the soil surface. In the 0-0.20 m layer, a 100-point geo-referenced grid covering two taxonomic soil classes was used in assessment of the following soil properties: soil particle density (Pd and bulk density (Bd; total porosity (Tp, macroporosity (Macro and microporosity (Micro; available water capacity (AWC; sand, silt, clay, and dispersed clay in water (Disp clay contents; electrical conductivity (EC; and weighted average diameter of aggregates (WAD. Soil depth to the top of the B horizon was also measured before leveling. The overall effect of leveling on selected soil physical properties was evaluated by paired "t" tests. The effect on the variability of each property was evaluated through the homogeneity of variance test. The thematic maps constructed by kriging or by the inverse of the square of the distances were visually analyzed to evaluate the effect of leveling on the spatial distribution of the properties and of the top of the B horizon in relation to the soil surface. Linear regression models were fitted with the aim of evaluating the relationship between soil properties and the magnitude of cuts and fills. Leveling altered the mean value of several soil properties and the agronomic effect was negative. The mean values of Bd and Disp clay increased and Tp, Macro and Micro, WAD, AWC and EC decreased. Spatial distributions of all

  7. Cast microstructure and tribological properties of particulate TiC-reinforced Ni-base or stainless steel matrix composites

    Energy Technology Data Exchange (ETDEWEB)

    Skolianos, S. (Department of Mechanical Engineering, Aristoteles University of Thessaloniki, Thessaloniki (Greece)); Kattamis, T.Z. (Department of Metallurgy, Institute of Materials Science, University of Connecticut, Storrs, CT 06269-3136 (United States)); Chen, M. (Department of Metallurgy, Institute of Materials Science, University of Connecticut, Storrs, CT 06269-3136 (United States)); Chambers, B.V. (Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States))

    1994-06-15

    Particulate TiC-reinforced nickel, 304 stainless steel and IN-100 nickel-base superalloy matrix composites were processed by precipitating the carbide during solidification of a melt of appropriate composition at various cooling rates. The microstructure and tribological properties of prepared specimens were evaluated. The microstructures of these composites can be controlled by controlling melt composition and homogeneity, as well as cooling rate. The specific wear rate decreased with increasing volume fraction of carbide and decreasing carbide particle size and spacing. For given volume fraction of carbide and carbide particle size composites with a softer matrix exhibited a higher wear rate and vice versa. The difference in wear rate among the three types of composites slightly decreased with increasing volume fraction carbide. Microhardness increased with increasing volume fraction of carbide. The friction coefficient between a diamond stylus and the polished specimen surface decreased with increasing volume fraction of carbide and decreasing particle size and spacing. For given volume fraction of carbide and carbide particle size the friction coefficient decreased with increasing matrix microhardness. For all composites a lower friction coefficient corresponded to a higher wear resistance. ((orig.))

  8. Optical properties of a long dynamic range chemical UV dosimeter based on solvent cast polyvinyl chloride (PVC).

    Science.gov (United States)

    Amar, Abdurazaq; Parisi, Alfio V

    2013-11-01

    The dosimetric properties of the recently introduced UV dosimeter based on 16 μm PVC film have been fully characterised. Drying the thin film in air at 50 °C for at least 28 days was found to be necessary to minimise the temperature effects on the dosimeter response. This research has found that the dosimeter response, previously reported to be mainly to UVB, has no significant dependence on either exposure temperature or dose rate. The dosimeter has negligible dark reaction and responds to the UV radiation with high reproducibility. The dosimeter angular response was found to have a similar pattern as the cosine function but deviates considerably at angles larger than 70°. Dose response curves exhibit monotonically increasing shape and the dosimeter can measure more than 900 SED. This is about 3 weeks of continuous exposure during summer at subtropical sites. Exposures measured by the PVC dosimeter for some anatomical sites exposed to solar radiation for twelve consecutive days were comparable with those concurrently measured by a series of PPO dosimeters and were in line with earlier results reported in similar studies.

  9. A new casting defect healing technology

    Energy Technology Data Exchange (ETDEWEB)

    Hodge, E.S.; Reddoch, T.W. [ForMat Industries, Inc., Knoxville, TN (United States); Viswanathan, S. [Oak Ridge National Lab., TN (United States)

    1997-01-01

    A new technology is presented for healing of defects in 356 aluminium alloys that provides economic upgrading of these cast alloys. It uses pneumatic isostatic forging (PIF) to produce high quality Al alloys products with enhanced mechanical properties uniform throughout the part, allowing higher design allowables and increased usage of Al alloy castings. The fundamental mechanism underlying PIF is a single mode plastic deformation process that uses isostatic application of pressures for 10-30 seconds at temperature. The process can be integrated in-line with other production operations, i.e., using the latent heat from the previous casting step. Results of applying the PIF process indicate lower cost and significant improvement in mechanical properties that rival and often exceed corresponding properties of other technologies like hot isostatic pressing and related processes. This process offers many advantages that are described in this paper in addition to presenting case histories of property enhancement by PIF and the mechanism responsible for property enhancement.

  10. Effects of rolling temperature on microstructure, texture, formability and magnetic properties in strip casting Fe-6.5 wt% Si non-oriented electrical steel

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Hai-Tao, E-mail: liuht@ral.neu.edu.cn [State Key Laboratory of Rolling and Automation, Northeastern University, P.O. Box 105, Shenyang 110819 (China); Institute of Research of Iron and Steel, Shasteel, Zhangjiagang 215625, Jiangsu (China); Li, Hao-Ze [State Key Laboratory of Rolling and Automation, Northeastern University, P.O. Box 105, Shenyang 110819 (China); Li, Hua-Long [Institute of Research of Iron and Steel, Shasteel, Zhangjiagang 215625, Jiangsu (China); Gao, Fei; Liu, Guo-Huai [State Key Laboratory of Rolling and Automation, Northeastern University, P.O. Box 105, Shenyang 110819 (China); Luo, Zhong-Han; Zhang, Feng-Quan; Chen, Sheng-Lin [National Engineering Research Center for Silicon Steel, Wuhan Iron & Steel (Group) Corp, Wuhan 430083 (China); Cao, Guang-Ming; Liu, Zhen-Yu; Wang, Guo-Dong [State Key Laboratory of Rolling and Automation, Northeastern University, P.O. Box 105, Shenyang 110819 (China)

    2015-10-01

    Fe-6.5 wt% Si non-oriented electrical steel sheets with a thickness of 0.50 mm were produced by using a new processing route: strip casting followed by hot rolling, intermediate temperature (150–850 °C) rolling and final annealing. The present study focused on exploring the effects of rolling temperature varying from 150 to 850 °C on the microstructure and texture evolution, the formability and final magnetic properties. The microstructure and texture evolution at the various processing steps were investigated in detail by using OM, XRD, EBSD and TEM. It was found that the formability during rolling, the microstructure and texture before and after annealing and final magnetic properties highly depended on rolling temperature. The formability during rolling was gradually improved with increasing rolling temperature due to the slipping of dislocation. In particular, the rolling temperature dominated the formation of in-grain shear bands in the rolled microstructure, which played an important role in the development of final recrystallization microstructure and texture. In the case of lower temperature (150–450 °C) rolling, an inhomogeneous microstructure with a large amount of in-grain shear bands was formed in the rolled sheets, which finally resulted in a fine and inhomogeneous annealing microstructure dominated by mild λ-fiber texture composed of cube and {001}〈210〉 components and α*-fiber texture concentrated on {115}〈5–10 1〉 component. By contrast, in the case of higher temperature (650–850 °C) rolling, a relatively homogeneous microstructure without in-grain shear bands was formed instead in the rolled sheets, which finally led to a coarse and relatively homogeneous annealing microstructure characterized by strong α-fiber and γ-fiber texture. Accordingly, on the whole, both the magnetic induction (B{sub 8} and B{sub 50}) and iron loss (P{sub 15/50} and P{sub 10/400}) decreased with raising rolling temperature. - Highlights: • Fe−6

  11. Materials processing threshold report: 2. Use of low gravity for cast iron process development

    Science.gov (United States)

    Frankhouser, W. L.

    1980-01-01

    Potential applications of a low gravity environment of interest to the commercial producers of cast iron were assessed to determine whether low gravity conditions offer potential opportunities to producers for improving cast iron properties and expanding the use of cast irons. The assessment is limited to the gray and nodular types of iron, however, the findings are applicable to all cast irons. The potential advantages accrued through low gravity experiments with cast irons are described.

  12. Tensile Properties and Fracture Behavior of Aluminum Alloy Foam Fabricated from Die Castings without Using Blowing Agent by Friction Stir Processing Route

    Directory of Open Access Journals (Sweden)

    Yoshihiko Hangai

    2014-03-01

    Full Text Available Al foam has been used in a wide range of applications owing to its light weight, high energy absorption and high sound insulation. One of the promising processes for fabricating Al foam involves the use of a foamable precursor. In this study, ADC12 Al foams with porosities of 67%–78% were fabricated from Al alloy die castings without using a blowing agent by the friction stir processing route. The pore structure and tensile properties of the ADC12 foams were investigated and compared with those of commercially available ALPORAS. From X-ray computed tomography (X-ray CT observations of the pore structure of ADC12 foams, it was found that they have smaller pores with a narrower distribution than those in ALPORAS. Tensile tests on the ADC12 foams indicated that as their porosity increased, the tensile strength and tensile strain decreased, with strong relation between the porosity, tensile strength, and tensile strain. ADC12 foams exhibited brittle fracture, whereas ALPORAS exhibited ductile fracture, which is due to the nature of the Al alloy used as the base material of the foams. By image-based finite element (FE analysis using X-ray CT images corresponding to the tensile tests on ADC12 foams, it was shown that the fracture path of ADC12 foams observed in tensile tests and the regions of high stress obtained from FE analysis correspond to each other. Therefore, it is considered that the fracture behavior of ADC12 foams in relation to their pore structure distribution can be investigated by image-based FE analysis.

  13. Effect of Bi modification treatment on microstructure, tensile properties, and fracture behavior of cast Al-Mg2Si metal matrix composite

    Directory of Open Access Journals (Sweden)

    Wu Xiaofeng

    2013-01-01

    Full Text Available Bi has a good modification effect on the hypoeutectic Al-Si alloy, and the morphology of eutectic Si changes from coarse acicular to fine fibrous. Based on the similarity between Mg2Si and Si phases in crystalline structure and crystallization process, the present study investigated the effects of different concentrations of Bi on the microstructure, tensile properties, and fracture behavior of cast Al-15wt.%Mg2Si in-situ metal matrix composite. The results show that the addition of the proper amount of Bi has a significant modification effect on both primary and eutectic Mg2Si in the Al-15wt.%Mg2Si composite. With an increase in Bi content from 0 to 1wt.%, the morphology of the primary Mg2Si is changed from irregular or dendritic to polyhedral shape; and its average particle size is significantly decreased from 70 to 6 μm. Moreover, the morphology of the eutectic Mg2Si phase is altered from flake-like to very short fibrous or dot-like. When the Bi addition exceeds 4.0wt.%, the primary Mg2Si becomes coarse again. However, the eutectic Mg2Si still exhibits the modified morphology. Tensile tests reveal that the Bi addition can improve the tensile strength and ductility of the material. Compared with those of the unmodified composite, the ultimate tensile strength and percentage elongation after fracture with 1.0wt.% Bi increase 51.2% and 100%, respectively. At the same time, the Bi addition changes the fracture behavior from brittle to ductile.

  14. Glovebox Advanced Casting System Casting Optimization

    Energy Technology Data Exchange (ETDEWEB)

    Fielding, Randall Sidney [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-03-01

    Casting optimization in the GACS included three broad areas; casting of U-10Zr pins, incorporation of an integral FCCI barrier, and development of a permanent crucible coating. U-10Zr casting was improved over last year’s results by modifying the crucible design to minimize contact with the colder mold. Through these modifications casting of a three pin batch was successful. Incorporation of an integral FCCI barrier also was optimized through furnace chamber pressure changes during the casting cycle to reduce gas pressures in the mold cavities which led to three full length pins being cast which incorporated FCCI barriers of three different thicknesses. Permanent crucible coatings were tested against a base case; 1500°C for 10 minutes in a U-20Pu-10Zr molten alloy. None of the candidate coating materials showed evidence of failure upon initial visual examination. In all areas of work a large amount of characterization will be needed to fully determine the effects of the optimization activities. The characterization activities and future work will occur next year.

  15. STUDY ON MACRO AND MICRO MODELING ON SOLIDIFICATION PROCESS OF SHAPED CASTING

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Facing the market economy and global challenge the development of manufacturing industry especially casting industry is critical to the national economy. To reform the traditional casting industry by using computer technology is one of the hottest research frontiers studied by many researchers and engineers. Computer simulation of solidification process of shaped casting can assure the quality of casting, optimize the casting technology, shorten the lead time and therefore decrease the developing and manufacturing cost. Recently, numerical simulation of mold-filling and solidification processes of shaped casting and prediction of microstructure and property as well are extensively studied and put into application in many casting plants with many successful simulation cases.

  16. Investigation of Microstructure and Mechanical Properties of Centrifugal Casting Mg-Zn-Y-Zr Alloy%离心铸造Mg-Zn-Y-Zr合金的显微组织与力学性能

    Institute of Scientific and Technical Information of China (English)

    王晓佳; 唐伟能; 赵忠兴; 陈荣石

    2012-01-01

    采用离心铸造法和金属型重力铸造法制备了Mg-6wt%Zn-1 wt%Y-0.5wt%Zr(简写为ZW61,下同)合金,比较了合金的铸态显微组织及力学性能.结果表明,离心铸造镁合金的晶粒组织得到明显细化,力学性能得到显著提高.利用扫描电子显微镜(SEM)、X射线衍射仪(XRD)研究了ZW61合金的显微组织相组成,基体相均为α-Mg相,ZW61合金的第二相由1相(Mg3Zn6Y)和W相(Mg3Zn3Y2)组成.根据ImageJ软件分析,离心铸件第二相的面积分数比金属型铸件的小,离心铸造中共晶转变L→α-Mg+W和共析转变L+W→α-Mg+I被抑制,导致I、W相减少,形成以过饱和初生相α-Mg为主的凝固组织.离心铸件的塑性特征优于金属型铸件.%Mg-6wt%Zn-lwt%Y-0.5wt%Zr (ZW6I) alloy was prepared by centrifugal casting and metal mould casting respectively. The as-cast microstructure and mechanical properties of the alloys were compared. The results show that the microstructure of centrifugal casting magnesium alloy is significantly refined, and its mechanical properties are improved. The microstructure and phase composition of ZW61 alloy were investigated through SEM and XRD. It was found that the matrix phase of both the alloys is α-Mg phase, and the second phase of ZW61 alloy are composed of I-phase (Mg3Zn6Y) and W- phase (Mg3Zn3Y2). According to the ImageJ software analysis, the area fraction of the second phase in the centrifugal casting alloy is lower than that in the metal mould casting alloy. In centrifugal casting process, the eutectic t ransformation of L → α-Mg + W and eutectoid transformation of L+ W→ α-Mg + I were suppressed, leading to the reduced amount of I-phase and W-phase, and form a solidification microstructure with the saturated primary phase consisting mainly of α-Mg phase. The centrifugal casting alloy has more plastic features than the metal mould casting alloy.

  17. Control of microstructure of cast irons Indefinite Chill Double Pour-ICDP

    Directory of Open Access Journals (Sweden)

    T.Válek

    2011-10-01

    Full Text Available ICDP cast irons designated for working layer of centrifugal cylinders of rolling mill must have precisely defined properties. The most closely observed parameters of the ICDP (Indefinite Child Double Pour cast irons are the following: the amount of graphite in a microstructure and hardness of base metal material. Secretion of graphite in cast iron with ledeburitic basic metal compound is a complex process that can be controlled and managed with the use of thermal analysis. On the basis of the evaluation of cooling curve parameters of cast iron there is performed metallurgical adjustment of meltage by adding elements supporting graphite end carbide formation into cast iron. The identified structural and mechanical properties of ICDP cast irons were correlated with recorded KO. Subsequently, a methodology for control of the metallurgical adjustment of cast iron before casting was proposed so as to ensure the desired microstructure and properties the ICDP cast iron.

  18. EVALUATION OF THE IMPACT OF THIN POURS ON SALTSTONE PROPERTIES

    Energy Technology Data Exchange (ETDEWEB)

    Cozzi, A.; Langton, C.; Fox, K.

    2012-10-02

    testing showed increased flow when the number of cold joints was increased. Compressive strength testing showed that the maximum load at the onset of cracking was reduced by approximately 26% for those samples that contained cold joints as compared to the monolithic samples. The number of cold joints in the sample had no significant impact on the maximum load prior to cracking. The porosity of the samples was not influenced by cold joints. This result was expected as the porosity is a material property affected by the properties of the components (premix and salt solution) and the water to premix ratio. Overall, the only obvious impact of cold joints in the samples was to significantly increase hydraulic conductivity in the direction parallel to the cold joints. An increasing number of cold joints (thin layers) in the simulated saltstone samples did not exacerbate this effect, nor did it have a negative impact on the Leachability Indices or porosity for surfaces exposed for approximately four days. The presence of a cold joint reduced the compressive strength of the material, although this impact was seen regardless of the number of cold joints in the sample.

  19. Preferential dissolution behaviour in Ni–Cr dental cast alloy

    Indian Academy of Sciences (India)

    Viswanathan S Saji; Han Cheol Choe

    2010-08-01

    A Ni–Cr–Mo dental alloy was fabricated by three different casting methods, viz. centrifugal casting, high frequency induction casting and vacuum pressure casting. The dependence of cast microstructure on the electrochemical corrosion behaviour was investigated using potentiodynamic cyclic and potentiostatic polarization techniques, impedance spectroscopy and scanning electron microscopy. The experimental results were compared and discussed with those obtained for a Co–Cr–Mo counterpart. The results of the study showed that the variation in casting morphologies with casting methods has only marginal influence in the overall corrosion resistance of Ni–Cr and Co–Cr dental alloys. There was severe preferential dissolution of Ni rich, Cr and Mo depleted zones from the Ni–Cr–Mo alloy. The overall corrosion resistance property of the Co–Cr base alloy was better than that of the Ni–Cr base alloy.

  20. Metallic Fuel Casting Development and Parameter Optimization Simulations

    Energy Technology Data Exchange (ETDEWEB)

    R.S. Fielding; J. Crapps; C. Unal; J.R. Kennedy

    2013-03-01

    One of the advantages of metallic fuel is the abilility to cast the fuel slugs to near net shape with little additional processing. However, the high aspect ratio of the fuel is not ideal for casting. EBR-II fuel was cast using counter gravity injection casting (CGIC) but, concerns have been raised concerning the feasibility of this process for americium bearing alloys. The Fuel Cycle Research and Development program has begun developing gravity casting techniques suitable for fuel production. Compared to CGIC gravity casting does not require a large heel that then is recycled, does not require application of a vacuum during melting, and is conducive to re-usable molds. Development has included fabrication of two separate benchscale, approximately 300 grams, systems. To shorten development time computer simulations have been used to ensure mold and crucible designs are feasible and to identify which fluid properties most affect casting behavior and therefore require more characterization.

  1. IMPACT OF COOKING HOMOGENEITY ON PULP STRENGTH PROPERTIES

    Institute of Scientific and Technical Information of China (English)

    BofengMao

    2004-01-01

    Cooking homogeneity of kraft pulping can havesignificant impact on pulp strength properties. Wehave studied cooking homogeneity of two kraftdigesters within Stora Enso. One of the digesters is aone-vessel hydraulic continuous digester (digester A)and the other one is a two-vessel vapor/liquor phasecontinuous digester (digester B). They are located inthe same mill and use the same softwood chipquality. Due to the differences in chip pre-steamingand cooking facilities and conditions, significantdifferences in pulp strength properties, reject contentsand kappa variations have been found between thepulps produced in the two digesters. Digester A has amodem chip bin with efficient pre-heating and airremoval, whereas digester B has poor chippre-steaming conditions. Our strength deliverystudies show that although the two digesters producepulps with the same kappa number and viscosity, thepulp produced in digester A has about 20% higherstrength delivery, l%-unit (based on wood) lowerreject content and lower kappa variations based onFTIR spectra analysis on pulp sheet than the pulpproduced in digester B.Results of the studies indicate that morehomogeneous cooking,variation in the fibers,i.e., lower lignin/kappa leads to improved pulpstrength properties. Efficient chip pre-steaming isimportant/essential for achieving homogeneouscooking. Rebuilding the equipment for improvingchip pre-steaming conditions of digester B is to becarded out.

  2. IMPACT OF COOKING HOMOGENEITY ON PULP STRENGTH PROPERTIES

    Institute of Scientific and Technical Information of China (English)

    Bofeng Mao

    2004-01-01

    Cooking homogeneity of kraft pulping can have significant impact on pulp strength properties. We have studied cooking homogeneity of two kraft digesters within Stora Enso. One of the digesters is a one-vessel hydraulic continuous digester (digester A)and the other one is a two-vessel vapor/liquor phase continuous digester (digester B). They are located in the same mill and use the same softwood chip quality. Due to the differences in chip pre-steaming and cooking facilities and conditions, significant differences in pulp strength properties, reject contents and kappa variations have been found between the pulps produced in the two digesters. Digester A has a modem chip bin with efficient pre-heating and air removal, whereas digester B has poor chip pre-steaming conditions. Our strength delivery studies show that although the two digesters produce pulps with the same kappa number and viscosity, the pulp produced in digester A has about 20% higher strength delivery, l%-unit (based on wood) lower reject content and lower kappa variations based on FTIR spectra analysis on pulp sheet than the pulp produced in digester B.Results of the studies indicate that more homogeneous cooking, i.e., lower lignin/kappa variation in the fibers, leads to improved pulp strength properties. Efficient chip pre-steaming is important/essential for achieving homogeneous cooking. Rebuilding the equipment for improving chip pre-steaming conditions of digester B is to be carried out.

  3. Evolution of the microstructure and magnetic properties of as-cast and melt spun Fe{sub 2}NiAl alloy during aging

    Energy Technology Data Exchange (ETDEWEB)

    Menushenkov, V.P., E-mail: menushenkov@gmail.com; Gorshenkov, M.V.; Shchetinin, I.V.; Savchenko, A.G.; Savchenko, E.S.; Zhukov, D.G.

    2015-09-15

    Fe{sub 2}NiAl-based alloy with the nominal composition Fe{sub 51.1}Ni{sub 23.5}Al{sub 23.7}Si{sub 1.7} was prepared by casting and melt-spinning. Comparison of the phase composition, microstructure and magnetic properties of water-quenched bulk samples and melt spun ribbons after isothermal aging in the 500–900 °C range were carried out. TEM investigations of the decomposition of the solid solution into β- and β{sub 2} phases during cooling or quenching and subsequent aging have revealed different types of decomposition products. The optimal periodic modulated structure with coercive force H{sub c}~700 Oe was observed after cooling of as-cast alloy at a critical rate. In this structure the paramagnetic β{sub 2} phase forms a continuous network that isolates elongated single domain ferromagnetic β particles. The water-quenched bulk samples and melt spun ribbons were characterized by zone structure with zones about 10 nm and 4 nm in size. The isothermal aging of quenched samples resulted in the formation of modulated microstructure dissimilar to those of the optimal state. The coarsening of ferromagnetic β particles as well as deterioration of the magnetic insulation of β particles occur in bulk samples after aging at T{sub ag}>700 °C that decreases H{sub c}≤350 Oe. The dependence δ{sub M}(H) was measured and negative values of δ{sub M}(H) in the H=0–2000 Oe range indicate that magnetostatic interactions between the β particles are dominant. The melt spun ribbons were characterized by the presence of antiphase domain boundaries (APD) and discontinuous precipitation (DP) products at grain boundaries (GB). The cellular areas at GBs consisting of alternating lamellas of β′- and β{sub 2}′ type phases were formed after aging the ribbons at T{sub ag}>500 °C. At T{sub ag}>700 °C the modulated structure formed inside grains and the wide intergranular double-layer of β and β{sub 2} phases develops by the coalescence of the primary DP products that

  4. Evolution of halictine castes

    Science.gov (United States)

    Knerer, Gerd

    1980-03-01

    Social halictine bees have female castes that range from species with no size differences to those with a discrete bimodality. Female caste differences are inversely correlated with the number of males produced in the first brood. It is proposed that the sexual dimorphism of solitary forms is being usurped by the female caste system of species in the process of turning social. Thus, caste differences and summer male suppression are greatest in the social species originating from solitary precursors with distinct sexual dimorphism, and are least in species evolving from solitary ancestors with a continuous sexual polymorphism.

  5. Mandated political representation and crimes against the low castes

    OpenAIRE

    Girard, Victoire

    2016-01-01

    Mandated political representation over the last twenty years has had a different impact on the reporting of crime by the low castes than what is observed for the reporting of crime by women. I exploit the timing of the implementation of mandated political representation of the low castes to examine its effect on crime reports by these people. Mandated political representation of the low castes in India appears to affect the declaration of crime only for two very specific crime categories: ide...

  6. Optimization of squeeze casting parameters for non symmetrical AC2A aluminium alloy castings through Taguchi method

    Energy Technology Data Exchange (ETDEWEB)

    Senthil, P. [Coimbatore Institute of Engineering and Technology, Coimbatore (India); Amirthagadeswaran, K. S. [Government College of Technology, Coimbatore (India)

    2012-04-15

    This paper reports a research in which an attempt was made to prepare AC2A aluminium alloy castings of a non symmetrical component through squeeze casting process. The primary objective was to investigate the influence of process parameters on mechanical properties of the castings. Experiments were conducted based on orthogonal array suggested in Taguchi's offline quality control concept. The experimental results showed that squeeze pressure, die preheating temperature and compression holding time were the parameters making significant improvement in mechanical properties. The optimal squeeze casting condition was found and mathematical models were also developed for the process.

  7. Caste in Itself, Caste and Class, or Caste in Class

    OpenAIRE

    Ramkrishna Mukherjee

    2015-01-01

    After the British conquered Bengal and eventually the whole of India,they set out to administer the colony. In this context they encountered two phenomena with which they were not familiar: (1) the relation of people to land for production (and not for revenue receiving, household living, etc.), and (2) the caste system of India, viz. the jati strati?cation of society.

  8. Rare Earth Additions in Continuously Cast Steel

    Science.gov (United States)

    Wilson, William G.; Heaslip, L. J.; Sommerville, I. D.

    1985-09-01

    Rare earth (lanthanide metals) addiiions to continuously cast steel are particularly advantageous because of their ability to refine as-cast structures, reduce segregation and increase hot ductility at temperatures just below that of solidification. The complete shape control of sulfides in steels containing Rare Earth Metals (REM), whether continuously cast or ingot cast, is primarily responsible for improvements in ductility related mechanical properties, weldability, fatigue resistance and resistance to hydrogen damage. Complete sulfide shape control can be obtained with REM additions at sulfur levels as high as.020%. The greatest improvements, however, are obtained with REM additions to low sulfur steels. However, to achieve full operational advantages afforded by REM, nozzle blockage problems must be circumvented. Water model studies indicate a possible solution.

  9. Advanced lost foam from casting technology

    Energy Technology Data Exchange (ETDEWEB)

    Bates, C. E.; Littleton, H. E.; Askeland, D.; Griffin, J.; Miller, B. A.; Sheldon, D. S.

    1996-05-01

    Previous research made significant advances in understanding the Lost Foam Casting (LFC) Process and clearly identified areas where additional research was needed to improve the process and make it more functional in an industrial environment. The current project focused on five areas listed as follows: Task 1: Precision Pattern Production Task 2: Pattern Coating Consistency Task 3: Sand Fill and Compaction Effects Task 4: Pattern Gating Task 5: Mechanical Properties of Castings. This report summarizes the work done under the current contract in all five areas in the period of October 1, 1994 through December 31, 1995. Twenty-eight (28) companies jointly participate in the project. These companies represent a variety of disciplines, including pattern designers, pattern producers, coating manufacturers, plant design companies, compaction equipment manufacturers, casting producers, and casting buyers.

  10. Effect of Zr Purity and Oxygen Content on the Structure and Mechanical Properties of Melt-Spun and Suction-Cast Cu46Zr42Al7Y5 Alloy

    Directory of Open Access Journals (Sweden)

    Kozieł T.

    2016-06-01

    Full Text Available The effect of oxygen content in zirconium on the structure and mechanical properties of the Cu46Zr42Al7Y5 alloy, in the form of melt-spun ribbons and suction-cast rods, was investigated. Two types of Zr, rod and crystal bar of different nominal purities and oxygen contents, were used to synthesize the alloy by arc melting. Rapidly solidified ribbons were produced by melt spinning and their amorphous structures were confirmed by X-ray diffractometry (XRD and differential scanning calorimetry (DSC. Bulk samples in the form of rods were cast using a special water-cooled suction casting unit attached to the arc melting system. XRD and DSC studies proved the amorphous structure of the bulk alloy synthesized from low-oxygen Zr and partial crystallization of the same alloy for high-oxygen Zr. In both bulk samples, uniformly distributed crystalline particles were identified as yttrium oxides. Higher mean compressive strength of amorphous alloy was observed. The hardness of amorphous phase was close to 500 HV1 in both bulk alloys, while the hardness of crystalline dendritic areas, observed in the alloy synthesized from high oxygen Zr, was lower by about 50 HV1.

  11. Effect composition of SiCp and TiB to the mechanical properties of composite Al7Si-Mg-SiCp by the method of semi solid stir casting

    Science.gov (United States)

    Bhiftime, E. I.; Sulardjaka, Nugroho, Sri

    2016-04-01

    Recently, studies on Aluminum Matrix Composite (AMC) were growing rapidly. AMC reinforced with SiCp particles in the semi solid stir casting method was the most simple way. In particular, the purpose of the present study was to investigate the effect composition of SiCp and TiB to the mechanical properties of the composites Al7Si-Mg-SiCp and Al7Si-Mg-TiB-SiCp. The composites used were Al7Si as the matrix and SiCp as the reinforcement (10, 15, 20 wt%). The casting method used on the study was the semi solid stir casting. The matrix was melted at the temperature of 800 °C. Then, the stirring process started at 590 °C with the speed of 500 rpm for 180 seconds. The composites was heated again until the pouring temperature was at 750 °C. The results of the present study indicated to be successful in which SiCp particles dispersed uniformly in the matrix composites. Further, the hardness value and porosity of the composites Al7Si-Mg-SiCp and Al7Si-Mg-TiB-SiCp increased along with the addition of TiB. Besides, the hardness value increased in the average of 10.5% at the variation of 20% SiCp. Whereas, the porosity value increased in the average of 54.3% at the variation of 20% SiCp.

  12. Economic impact of fuel properties on turbine powered business aircraft

    Science.gov (United States)

    Powell, F. D.

    1984-01-01

    The principal objective was to estimate the economic impact on the turbine-powered business aviation fleet of potential changes in the composition and properties of aviation fuel. Secondary objectives include estimation of the sensitivity of costs to specific fuel properties, and an assessment of the directions in which further research should be directed. The study was based on the published characteristics of typical and specific modern aircraft in three classes; heavy jet, light jet, and turboprop. Missions of these aircraft were simulated by computer methods for each aircraft for several range and payload combinations, and assumed atmospheric temperatures ranging from nominal to extremely cold. Five fuels were selected for comparison with the reference fuel, nominal Jet A. An overview of the data, the mathematic models, the data reduction and analysis procedure, and the results of the study are given. The direct operating costs of the study fuels are compared with that of the reference fuel in the 1990 time-frame, and the anticipated fleet costs and fuel break-even costs are estimated.

  13. Combining Aluminum Heat Treat with Hot Isostatic Pressing:A Comparison of Structure, Properties, and Processing Routes for a Cast Al-Si-Mg Alloy

    Institute of Scientific and Technical Information of China (English)

    Stephen J. Mashl

    2004-01-01

    Bodycote researchers have successfully demonstrated that a T6 heat treatment can be integrated with Densal(R), a proprietary, aluminum specific, hot isostatic pressing (HIP) process. In this combined operation, at least a portion of the solution heat treatment is conducted at elevated pressure. During development, two issues, adiabatic cooling during depressurization and a possible variation in the kinetics of homogenization resulting from conducting the solution heat treat at elevated pressure were perceived as factors which could alter the heat treat response fiom that seen in conventional processing.This paper reviews the results of experiments performed to A1-Si-Mg (A356.0) castings subjected to both combined and conventional processing routes. Results indicate that the combined HIP and heat treat process is an efficient means of achieving a microstructure characteristic of a conventionally T6 processed material while eliminating porosity within the casting. Further, the fatigue life of an A356.0 casting processed using the combined cycle can be improved by more than an order of magnitude over the as-cast and T6 treated component.

  14. Recent development of ductile cast iron production technology in China

    OpenAIRE

    Cai Qizhou; Wei Bokang

    2008-01-01

    Recent progress in the production and technology of ductile cast iron castings in China is reviewed. The manufacture and process control of as-cast ductile iron are discussed. The microstructure, properties and application of partial austenitization normalizing ductile iron and austempered ductile iron (ADI) are briefl y depicted. The new development of ductile iron production techniques, such as cored-wire injection (wire-feeding nodularization) process, tundish cover ladle nodularizing proc...

  15. Dynamic control of crystallinity in polymer film casting process

    OpenAIRE

    Thananchai Leephakpreeda

    2005-01-01

    This paper presents an approach for dynamic control of crystallinity in polymer film casting process. As known, the transients of crystallization dictate the microstructures of semi-crystalline polymer during solidification. In turn, the properties of finished products can be determined by adjustable variables in polymer film casting process such as temperature of chill roll. In this work, an experimental model of the solidification in film casting process is derived by a system identificatio...

  16. Solidification and microstructure of thin walled ductile cast iron

    DEFF Research Database (Denmark)

    Pedersen, Karl Martin

    2006-01-01

    In the recent years there has been an increasing interest in light constructions in order to save weight in e.g. cars. Ductile cast iron has good mechanical properties but it is necessary to re­duce the wall thicknesses of the castings in order to reduce the weight. Reducing the wall thicknesses...... of the casting will increase the cooling rates and by that change the conditions for nucleation and growth during solidification....

  17. A cast orientation index.

    Science.gov (United States)

    Ivanhoe, J R; Mahanna, G K

    1994-12-01

    This article describes a technique that allows multiple master casts to be precisely oriented to the same path of insertion and withdrawal. This technique is useful in situations where multiple fixed prosthodontic preparations require surveyed restorations and a single master cast is not available.

  18. Higher Education's Caste System

    Science.gov (United States)

    Iannone, Ron

    2004-01-01

    In this article, the author discusses the history of the present caste system in higher education. He shows how the public's perception of this caste system is based on image and not usually on the quality of teaching and curriculum in colleges and universities. Finally, he discusses a model for accessibility to higher education and how higher…

  19. Caste and power

    DEFF Research Database (Denmark)

    Roy, Dayabati

    2011-01-01

    This paper explores the institution of caste and its operation in a micro-level village setting of West Bengal, an Indian state, where state politics at grass roots level is vibrant with functioning local self-government and entrenched political parties. This ethnographic study reveals that caste...

  20. Multi-layers castings

    Directory of Open Access Journals (Sweden)

    J. Szajnar

    2010-01-01

    Full Text Available In paper is presented the possibility of making of multi-layers cast steel castings in result of connection of casting and welding coating technologies. First layer was composite surface layer on the basis of Fe-Cr-C alloy, which was put directly in founding process of cast carbon steel 200–450 with use of preparation of mould cavity method. Second layer were padding welds, which were put with use of TIG – Tungsten Inert Gas surfacing by welding technology with filler on Ni matrix, Ni and Co matrix with wolfram carbides WC and on the basis on Fe-Cr-C alloy, which has the same chemical composition with alloy, which was used for making of composite surface layer. Usability for industrial applications of surface layers of castings were estimated by criterion of hardness and abrasive wear resistance of type metal-mineral.

  1. PRINCIPALLY NEW EFFECTIVE CASTING PROCESS OF THE HOLLOW CYLINDRICAL SLUGS OF CAST IRON BY METHOD OF DIRECTIONAL SOLIDIFICATION

    Directory of Open Access Journals (Sweden)

    E. I. Marukovich

    2010-01-01

    Full Text Available The advantages of the new method of the hollow ingots production of cast iron are presented. The thermal state of crystallizer at cyclic temperature influences on its inside face, the ingot hardening and cast iron structure formation in conditions of intensive one-sided heat sink is examined. The comparative data on properties and exploitation characteristics of the parts, produced by different ways of casting is given.

  2. Effect of Zr Purity and Oxygen Content on the Structure and Mechanical Properties of Melt-Spun and Suction-Cast Cu46Zr42Al7Y5 Alloy

    OpenAIRE

    Kozieł T.; Latuch J.; Cios G.; Bała P.

    2016-01-01

    The effect of oxygen content in zirconium on the structure and mechanical properties of the Cu46Zr42Al7Y5 alloy, in the form of melt-spun ribbons and suction-cast rods, was investigated. Two types of Zr, rod and crystal bar of different nominal purities and oxygen contents, were used to synthesize the alloy by arc melting. Rapidly solidified ribbons were produced by melt spinning and their amorphous structures were confirmed by X-ray diffractometry (XRD) and differential scanning calorimetry ...

  3. Genetic evidence on the origins of Indian caste populations.

    Science.gov (United States)

    Bamshad, M; Kivisild, T; Watkins, W S; Dixon, M E; Ricker, C E; Rao, B B; Naidu, J M; Prasad, B V; Reddy, P G; Rasanayagam, A; Papiha, S S; Villems, R; Redd, A J; Hammer, M F; Nguyen, S V; Carroll, M L; Batzer, M A; Jorde, L B

    2001-06-01

    The origins and affinities of the approximately 1 billion people living on the subcontinent of India have long been contested. This is owing, in part, to the many different waves of immigrants that have influenced the genetic structure of India. In the most recent of these waves, Indo-European-speaking people from West Eurasia entered India from the Northwest and diffused throughout the subcontinent. They purportedly admixed with or displaced indigenous Dravidic-speaking populations. Subsequently they may have established the Hindu caste system and placed themselves primarily in castes of higher rank. To explore the impact of West Eurasians on contemporary Indian caste populations, we compared mtDNA (400 bp of hypervariable region 1 and 14 restriction site polymorphisms) and Y-chromosome (20 biallelic polymorphisms and 5 short tandem repeats) variation in approximately 265 males from eight castes of different rank to approximately 750 Africans, Asians, Europeans, and other Indians. For maternally inherited mtDNA, each caste is most similar to Asians. However, 20%-30% of Indian mtDNA haplotypes belong to West Eurasian haplogroups, and the frequency of these haplotypes is proportional to caste rank, the highest frequency of West Eurasian haplotypes being found in the upper castes. In contrast, for paternally inherited Y-chromosome variation each caste is more similar to Europeans than to Asians. Moreover, the affinity to Europeans is proportionate to caste rank, the upper castes being most similar to Europeans, particularly East Europeans. These findings are consistent with greater West Eurasian male admixture with castes of higher rank. Nevertheless, the mitochondrial genome and the Y chromosome each represents only a single haploid locus and is more susceptible to large stochastic variation, bottlenecks, and selective sweeps. Thus, to increase the power of our analysis, we assayed 40 independent, biparentally inherited autosomal loci (1 LINE-1 and 39 Alu elements

  4. The ancient Chinese casting techniques

    Directory of Open Access Journals (Sweden)

    Tan Derui

    2011-02-01

    Full Text Available In the course of Chinese civilization, which lasted more than 5,000 years, casting production has made a huge contribution. In this paper, some representative metal castings were presented. According to their forming techniques, they can be grouped into stone mould casting, clay mould casting, ablation casting, lost wax casting, stack casting, permanent mould casting, sand casting, etc. According to their materials, they can be categorized into tin bronze, bimetallic bronze, malleable cast iron, ductile cast iron, brass, cupronickel alloy (Packtong, etc. According to their surface decorative techniques they can be devided into gem inlay, gilding, gold and silver inlay, copper inlay, engraved decoration, surface tin-enrichment, mother-of-pearl inlay, burnished works with gold or silver inlay, surface coloring and cloisonné enamel, etc.

  5. Caste in Itself, Caste and Class, or Caste in Class

    Directory of Open Access Journals (Sweden)

    Ramkrishna Mukherjee

    2015-08-01

    Full Text Available After the British conquered Bengal and eventually the whole of India,they set out to administer the colony. In this context they encountered two phenomena with which they were not familiar: (1 the relation of people to land for production (and not for revenue receiving, household living, etc., and (2 the caste system of India, viz. the jati strati?cation of society.

  6. Impact of soil properties on selected pharmaceuticals adsorption in soils

    Science.gov (United States)

    Kodesova, Radka; Kocarek, Martin; Klement, Ales; Fer, Miroslav; Golovko, Oksana; Grabic, Roman; Jaksik, Ondrej

    2014-05-01

    The presence of human and veterinary pharmaceuticals in the environment has been recognized as a potential threat. Pharmaceuticals may contaminate soils and consequently surface and groundwater. Study was therefore focused on the evaluation of selected pharmaceuticals adsorption in soils, as one of the parameters, which are necessary to know when assessing contaminant transport in soils. The goals of this study were: (1) to select representative soils of the Czech Republic and to measure soil physical and chemical properties; (2) to measure adsorption isotherms of selected pharmaceuticals; (3) to evaluate impact of soil properties on pharmaceutical adsorptions and to propose pedotransfer rules for estimating adsorption coefficients from the measured soil properties. Batch sorption tests were performed for 6 selected pharmaceuticals (beta blockers Atenolol and Metoprolol, anticonvulsant Carbamazepin, and antibiotics Clarithromycin, Trimetoprim and Sulfamethoxazol) and 13 representative soils (soil samples from surface horizons of 11 different soil types and 2 substrates). The Freundlich equations were used to describe adsorption isotherms. The simple correlations between measured physical and chemical soil properties (soil particle density, soil texture, oxidable organic carbon content, CaCO3 content, pH_H2O, pH_KCl, exchangeable acidity, cation exchange capacity, hydrolytic acidity, basic cation saturation, sorption complex saturation, salinity), and the Freundlich adsorption coefficients were assessed using Pearson correlation coefficient. Then multiple-linear regressions were applied to predict the Freundlich adsorption coefficients from measured soil properties. The largest adsorption was measured for Clarithromycin (average value of 227.1) and decreased as follows: Trimetoprim (22.5), Metoprolol (9.0), Atenolol (6.6), Carbamazepin (2.7), Sulfamethoxazol (1.9). Absorption coefficients for Atenolol and Metoprolol closely correlated (R=0.85), and both were also

  7. 热型连铸铝线的制备及其显微组织和性能%Preparation of aluminum wire by Ohno continuous casting and its microstructure and properties

    Institute of Scientific and Technical Information of China (English)

    胡炜; 王彦红; 赵小军; 肖来荣; 饶博; 章玮

    2015-01-01

    采用自制的热型连铸设备制备铝线材料,研究铸型温度和拉铸速度等工艺参数对材料表面质量、显微组织及力学性能的影响,通过对最佳工艺条件下制备的铸锭断口形貌进行观察和分析,探讨其相关机理。结果表明:当铸型温度为675~685℃、拉铸速度为90~120 mm/min时,可以制备出表面质量较佳的铸锭;同时,工艺参数会对晶体的择优取向产生一定影响,当铸型温度和拉铸速度分别为680℃和90 mm/min时,晶体的取向更倾向于沿〈100〉方向生长,铸型温度越高,铸锭力学性能越优异。当拉铸速度为90 mm/min时,制备的热型连铸铝线具有最佳的塑性加工能力。相比于普通多晶铝线,热型连铸铝线具有更好的塑性。%Aluminum wires were prepared using the self-made Ohno continuous casting equipment. The effects of process parameters, such as the mold temperature and casting rate, on the surface quality, microstructure and mechanical properties of aluminum wires were investigated. Besides, the microstructures of fracture surfaces of Al wires prepared under optimal process parameters were evaluated, and the relevant mechanisms were identified. The results show that the Al ingots with good surface quality can be successfully fabricated at the mold temperature of 675−685℃ and the casting speed of 90−120 mm/min. Meanwhile, the process parameters have a great effect on the preferred orientation of crystals. When the mold temperature is 680℃ and the casting speed is 90 mm/min, the crystal orientation of grain tends to grow along the direction of〈100〉. Moreover, when the casting speed is constant, the mechanical properties of ingots are improved with the increasing mold temperature. Furthermore, when the casting speed is 90 mm/min, the plastic processing capacity is the best. In comparison to polycrystalline Al wires, the Al wires prepared by Ohno continuous casting have better integrated

  8. Die Casting Semi-Solid ZL101 Alloy Prepared by Inclined Slope Cooling-Transferring Method and its Properties%ZL101过流冷却转移法半固态压铸工艺及性能研究

    Institute of Scientific and Technical Information of China (English)

    李璐; 周荣锋; 岑启宏; 黎振华; 蒋业华; 周荣

    2011-01-01

    Die casting semi-solid ZL101 alloy prepared by inclined slope cooling-transferring method was conducted. Effects of processing parameters on properties of semi-solid rheoforming ZL101 alloy die castings were investigated, and the change of properties of the semi-solid die casting ZL101 parts after T6 heat treatment was analyzed. Mechanical properties of semi-solid die casting parts were comparatively analyzed with those of conventional die casting parts. The results reveal that, the semi-solid die casting parts exhibit desirable mechanical properties with pouring at 595 ℃ and injecting at 1. 8 m/s, and the elongation is increased by 11% compared with that of conventional die casting parts at 630 ℃. Tensile strength and elongation of the semi-solid die casting parts after heat treatment are greatly improved. The fracture mechanism of both conventional die casting parts and semi-solid die casting parts are characterized by quasi-cleavage fracture, while semi-solid die casting parts after heat treatment are characterized by ductile fracture.%采用倾斜管过流冷却-转移法生产半固态流变压铸件,研究了压铸工艺对ZL101铝合金半固态流变压铸件性能的影响,以及半固态压铸件经T6热处理之后性能的改变.对比研究了液态与半固态压铸件的力学性能.结果表明,在浇注温度为595℃、压射速度为1.8 m/s时,压铸件性能最佳,此时较浇注温度为630℃的液态压铸件的抗拉强度提高了11%.经热处理的半固态压铸件抗拉强度与伸长率都得到改善.液态与半固态压铸件试样的拉伸断口为准解理断裂,经热处理的半固态压铸件试样的拉伸断口为韧性断裂.

  9. Physical Simulation of Investment Casting of Complex Shape Parts

    Science.gov (United States)

    Rahimian, Mehdi; Milenkovic, Srdjan; Maestro, Laura; De Azua, Aitor Eguidazu Ruiz; Sabirov, Ilchat

    2015-05-01

    Development of investment casting process has been a challenge for manufacturers of complex shape parts. Numerous experimental casting trials are typically carried out to determine the optimum casting parameters for fabrication of high-quality products. In this work, it is demonstrated that physical simulation of investment casting can successfully predict microstructure and hardness in as-cast complex shape parts. The physical simulation tool consists of a thermal model and melting/solidification experiments in thermo-mechanical simulator. The thermal model is employed to predict local cooling rate during solidification at each point of a casting. Melting/solidification experiments are carried out under controlled cooling rates estimated by the thermal model. Microstructural and mechanical characterization of the solidified specimens is performed; the obtained results predict the local microstructure and mechanical properties of the casting. This concept is applied to investment casting of complex shape nozzle guide vanes from Mar-M247 Ni-based superalloy. Experimental casting trials are performed and the outcomes of physical simulation tool are validated against experimental results. It is shown that phase composition, secondary dendrite arm spacing, grain size, γ/ γ' eutectic size and volume fraction, size and shape of carbide particles, and local microhardness can be predicted at each point of the casting via physical simulation.

  10. The potential of centrifugal casting for the production of near net shape uranium parts

    Energy Technology Data Exchange (ETDEWEB)

    Robertson, E. [United States Air Force Academy, Colorado Springs, CO (US). Dept. of Engineering Mechanics

    1993-09-01

    This report was written to provide a detailed summary of a literature survey on the near net shape casting process of centrifugal casting. Centrifugal casting is one potential casting method which could satisfy the requirements of the LANL program titled Near Net Shape Casting of Uranium for Reduced Environmental, Safety and Health Impact. In this report, centrifugal casting techniques are reviewed and an assessment of the ability to achieve the near net shape and waste minimization goals of the LANL program by using these techniques is made. Based upon the literature reviewed, it is concluded that if properly modified for operation within a vacuum, vertical or horizontal centrifugation could be used to safely cast uranium for the production of hollow, cylindrical parts. However, for the production of components of geometries other than hollow tubes, vertical centrifugation could be combined with other casting methods such as semi-permanent mold or investment casting.

  11. Light metal compound casting

    Institute of Scientific and Technical Information of China (English)

    Konrad; J.; M.; PAPIS; Joerg; F.; LOEFFLER; Peter; J.; UGGOWITZER

    2009-01-01

    ‘Compound casting’simplifies joining processes by directly casting a metallic melt onto a solid metal substrate. A continuously metallurgic transition is very important for industrial applications, such as joint structures of spaceframe constructions in transport industry. In this project, ‘compound casting’ of light metals is investigated, aiming at weight-saving. The substrate used is a wrought aluminium alloy of type AA5xxx, containing magnesium as main alloying element. The melts are aluminium alloys, containing various alloying elements (Cu, Si, Zn), and magnesium. By replacing the natural oxygen layer with a zinc layer, the inherent wetting difficulties were avoided, and compounds with flawless interfaces were successfully produced (no contraction defects, cracks or oxides). Electron microscopy and EDX investigations as well as optical micrographs of the interfacial areas revealed their continu- ously metallic constitution. Diffusion of alloying elements leads to heat-treatable microstructures in the vicinity of the joining interfaces in Al-Al couples. This permits significant variability of mechanical properties. Without significantly cutting down on wettability, the formation of low-melting intermetallic phases (Al3Mg2 and Al12Mg17 IMPs) at the interface of Al-Mg couples was avoided by applying a protective coating to the substrate.

  12. Effect of Gas Elements on Mechanical Properties of ZTC4 Cast Titanium Alloy%气体元素对ZTC4铸造钛合金力学性能的影响

    Institute of Scientific and Technical Information of China (English)

    刘宏宇; 赵军; 谢华生; 刘时兵; 史昆; 杨晓曦; 刘鸿羽

    2012-01-01

    为提高ZTC4钛合金铸件质量,研究了气体元素(H、N、O)含量对ZTC4铸造钛合金力学性能的影响.结果表明,氢、氮、氧在一定范围内能够提高合金的强度;氢控制在0.010%~0.012%,氮控制在0.01%~0.02%,氧控制在0.10%~0.15%时,有利于提高ZTC4钛铸件的综合性能.生产中对自耗电极、铸型、后处理等生产过程进行的技术规范严格控制有利于控制铸件中气体元素含量,获得优质的钛铸件.%To improve the quality of ZTC4 titanium alloy casting, the effects of gas elements (H, N, O) contents on its mechanical properties were studied. The results show that the given content of gas elements, hydrogen, nitrogen and oxygen, can improve the strength of the titanium alloy; it is beneficial to improving the comprehensive properties of ZTC4 titanium alloy casting that the hydrogen, nitrogen and oxygen contents are in the range of 0.010%-0.012%, 0.01%-0.02% and 0.10%-0.15%, respectively. Strictly controlling technical regulations of consumable electrode, mold and post treatment in the production benefits the gas contents control and the high quality casting.

  13. TODS BioCast User Manual, Forecasting 3D Satellite Derived Optical Properties Using Eulerian Advection Procedure, Version 1.0

    Science.gov (United States)

    2015-06-17

    materials) in aquatic environments. It requires a set of flow fields (North/South and East/West velocity components), bathymetric data, an initial...of forecasting applications and basic oceanographic/ aquatic research programs. A conceptual overview of forecasting the distribution of bio-optical...BioCast processing for Chesapeake Bay, Virginia during the Trident Warrior exercise using the MODIS satellite product for beam attenuation (proxy for

  14. Tensile properties and fracture characteristics of spray cast alloy IC6 (Ni-7.8Al-14Mo-0.05B)

    Institute of Scientific and Technical Information of China (English)

    MI Guo-fa; WANG Hong-wei; TIAN Shi-fan; LI Zhou; ZENG Song-yan

    2007-01-01

    Tensile testing results of spray cast Ni3Al-based superalloy indicated that the yield strength and tensile strength increase with the increasing of temperature and reached maximum at around 760℃, then decrease with the increasing of temperature. After high temperature isostatic pressing (HIP), yield strength decreased and ductility and tensile strength increased. Stereographic projection showed that no matter at room temperature, medium temperature or high temperature, cracks extend along (111).

  15. Impact of temperature on the biological properties of soil

    Science.gov (United States)

    Borowik, Agata; Wyszkowska, Jadwiga

    2016-01-01

    The aim of the study was to determine the response of soil microorganisms and enzymes to the temperature of soil. The effect of the temperatures: 5, 10, 15, 20, and 25°C on the biological properties of soil was investigated under laboratory conditions. The study was performed using four different soils differing in their granulometric composition. It was found that 15°C was the optimal temperature for the development of microorganisms in soil. Typically, in the soil, the highest activity of dehydrogenases was observed at 10-15°C, catalase and acid phosphatase - at 15°C, alkaline phosphatase at 20°C, urease and β-glucosidase at 25°C. The highest colony development index for heterotrophic bacteria was recorded in soils incubated at 25°C, while for actinomycetes and fungi at 15°C. The incubation temperature of soil only slightly changed the ecophysiological variety of the investigated groups of microorganisms. Therefore, the observed climate changes might have a limited impact on the soil microbiological activity, because of the high ability of microorganisms to adopt. The response of soil microorganisms and enzymes was more dependent on the soil granulometric composition, organic carbon, and total nitrogen than on its temperature.

  16. Impact behaviour of nylon-rubber blends: 5. Influence of the mechanical properties of the elastomer

    OpenAIRE

    Borggreve, R.J.M.; Gaymans, R.J.; Schuijer, J.

    1989-01-01

    Blends of 90wt% nylon-6 and 10wt% impact modifier were prepared. As impact modifiers were used: EPDM (ethylene propylene diene monomer) rubber, EPM (ethylene propylene monomer) rubber, polyethylene, four poly(ether esters) and some commercial impact modifers. EPDM, EPM and polyethylene were functionalized with maleic anhydride. The mechanical properties of the impact modifiers were tested with both a torsion pendulum test and a tensile test. The notched impact strength of the blends was measu...

  17. Laser surface treatment of grey cast iron for automotive applications

    NARCIS (Netherlands)

    Ocelik, V.; Tang, P.N.; de Boer, M.C.; de Oliveira, U.; de Hosson, J.T.M.; DeHosson, JTM; Brebbia, CA; Nishida, SI

    2005-01-01

    The surface of pearlitic grey cast iron was treated using a 2 kW Nd:YAG laser beam with the final aim to improve its surface properties, mainly for automotive applications. Two kinds of laser surface treatments were experimentally applied. In the laser surface hardening approach the surface of cast

  18. Symptomatic stent cast.

    LENUS (Irish Health Repository)

    Keohane, John

    2012-02-03

    Biliary stent occlusion is a major complication of endoscopic stent insertion and results in repeat procedures. Various theories as to the etiology have been proposed, the most frequently studied is the attachment of gram negative bacteria within the stent. Several studies have shown prolongation of stent patency with antibiotic prophylaxis. We report the case of stent occlusion from a cast of a previously inserted straight biliary stent; a "stent cast" in an 86-year-old woman with obstructive jaundice. This was retrieved with the lithotrypter and she made an uneventful recovery. This is the first reported case of a biliary stent cast.

  19. Symptomatic stent cast.

    Science.gov (United States)

    Keohane, John; Moore, Michael; O'Mahony, Seamus; Crosbie, Orla

    2008-02-01

    Biliary stent occlusion is a major complication of endoscopic stent insertion and results in repeat procedures. Various theories as to the etiology have been proposed, the most frequently studied is the attachment of gram negative bacteria within the stent. Several studies have shown prolongation of stent patency with antibiotic prophylaxis. We report the case of stent occlusion from a cast of a previously inserted straight biliary stent; a "stent cast" in an 86-year-old woman with obstructive jaundice. This was retrieved with the lithotrypter and she made an uneventful recovery. This is the first reported case of a biliary stent cast.

  20. CENTRIFUGAL CASTING MACHINE

    Science.gov (United States)

    Shuck, A.B.

    1958-04-01

    A device is described that is specifically designed to cast uraniumn fuel rods in a vacuunn, in order to obtain flawless, nonoxidized castings which subsequently require a maximum of machining or wastage of the expensive processed material. A chamber surrounded with heating elements is connected to the molds, and the entire apparatus is housed in an airtight container. A charge of uranium is placed in the chamber, heated, then is allowed to flow into the molds While being rotated. Water circulating through passages in the molds chills the casting to form a fine grained fuel rod in nearly finished form.