Fabrication of sacrificial anode cathodic protection through casting method

International Nuclear Information System (INIS)

Mohd Sharif Sattar; Muhamad Daud; Siti Radiah Mohd Kamarudin; Azali Muhamad; Zaiton Selamat; Rusni Rejab

2007-01-01

Aluminum is one of the few metals that can be cast by all of the processes used in casting metals. These processes consist of die casting, permanent mold casting, sand casting (green sand and dry sand), plaster casting, investment casting, and continuous casting. Other processes such as lost foam, squeeze casting, and hot isostatic pressing are also used. Permanent mold casting method was selected in which used for fabricating of sacrificial anode cathodic protection. This product was ground for surface finished and fabricated in the cylindrical form and reinforced with carbon steel at a center of the anode. (Author)

Casting metal microstructures from a flexible and reusable mold

International Nuclear Information System (INIS)

Cannon, Andrew H; King, William P

2009-01-01

This paper describes casting-based microfabrication of metal microstructures and nanostructures. The metal was cast into flexible silicone molds which were themselves cast from microfabricated silicon templates. Microcasting is demonstrated in two metal alloys of melting temperature 70 °C or 138 °C. Many structures were successfully cast into the metal with excellent replication fidelity, including ridges with periodicity 400 nm and holes or pillars with diameter in the range 10–100 µm and aspect ratio up to 2:1. The flexibility of the silicone mold permits casting of curved surfaces, which we demonstrate by fabricating a cylindrical metal roller of diameter 8 mm covered with microstructures. The metal microstructures can be in turn used as a reusable molding tool

Die Casting Mold Design for Aluminum Alloy Shell of Instrument

Directory of Open Access Journals (Sweden)

Li Yuanyuan

2015-01-01

Full Text Available This paper is about die casting mold design for aluminum alloy shell of instrument. Three-dimensional model of the casting and mold are designed by using Pro/Engineer and AutoCad which can analyze forming quality. Digital design and theoretical calculation can greatly shorten product development cycle and mold design cycle, improve the accuracy of product design and mold design, and reduce the cost of mold design.

Intelligent Machine Vision Based Modeling and Positioning System in Sand Casting Process

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Shahid Ikramullah Butt

2017-01-01

Full Text Available Advanced vision solutions enable manufacturers in the technology sector to reconcile both competitive and regulatory concerns and address the need for immaculate fault detection and quality assurance. The modern manufacturing has completely shifted from the manual inspections to the machine assisted vision inspection methodology. Furthermore, the research outcomes in industrial automation have revolutionized the whole product development strategy. The purpose of this research paper is to introduce a new scheme of automation in the sand casting process by means of machine vision based technology for mold positioning. Automation has been achieved by developing a novel system in which casting molds of different sizes, having different pouring cup location and radius, position themselves in front of the induction furnace such that the center of pouring cup comes directly beneath the pouring point of furnace. The coordinates of the center of pouring cup are found by using computer vision algorithms. The output is then transferred to a microcontroller which controls the alignment mechanism on which the mold is placed at the optimum location.

Development of heat pipe technology for permanent mold casting of magnesium alloys

International Nuclear Information System (INIS)

Elalem, K.; Mucciardi, F.; Gruzleski, J.E.; Carbonneau, Y.

2002-01-01

One of the key techniques for producing sound permanent mold castings is to use controlled mold cooling such as air cooling, water cooling and heat pipe cooling. Air-cooling has limited applications in permanent mold casting due to its low cooling capability and high cost. Water-cooling is widely used in permanent mold casting, but has some disadvantages such as safety issues and the facilities required. The early applications of heat pipes in permanent mold casting have shown tremendous results due to their high cooling rates, low cost and safety. In this work, a permanent mold for magnesium casting has been designed with the intention of producing shrinkage defects in the castings. Novel heat pipes that can generate high cooling rates have been constructed and used to direct the solidification in order to reduce the shrinkage. In this paper, the design of the mold and that of the heat pipes are presented. The results of some of the computer simulations that were conducted to determine casting conditions along with the potential of using heat pipes to direct the solidification are also presented. Moreover, a preliminary evaluation of the performance of heat pipes in the permanent mold casting of magnesium will also be discussed. (author)

Effects of heat pipe cooling on permanent mold castings of aluminum alloys

International Nuclear Information System (INIS)

Zhang, C.; Mucciardi, F.; Gruzleski, J.E.

2002-01-01

The temperature distribution within molds is a critical parameter in determining the ultimate casting quality in permanent mold casting processes, so there is a considerable incentive to develop a more effective method of mold cooling. Based on this consideration, a novel, effective and controllable heat pipe has been successfully developed and used as a new method of permanent mold cooling. Symmetric step casting of A356 alloy have been produced in an experimental permanent mold made of H13 tool steel, which is cooled by such heat pipes. The experimental results show that heat pipes can provide extremely high cooling rates in permanent mold castings of aluminum. The dendrite arm spacing of A356 alloy is refined considerably, and porosity and shrinkage of the castings are redistributed by the heat pipe cooling. Moreover, the heat pipe can be used to determine the time when the air gap forms at the interface between the mold and the casting. The effect of heat pipe cooling on solidification time of castings of A356 alloy with different coating types is also discussed in this paper. (author)

Numerical simulation of flow and compression of green sand

DEFF Research Database (Denmark)

Hovad, Emil

The focus of the industrial PhD project was concentrated on the production of the sand mold (green sand) which gives the cast component its final geometrical shape. In order to ensure a high quality of the cast component, it is important to control the manufacturing process of the mold itself so...... that it is homogeneous and stable. Therefore gaining a basic understanding of how the flow and deposition of green sand should be characterized and modelled was important, so that it could be used for simulation of the manufacturing process of the sand mold. The flowability of the green sand is important when the sand...... flows down through the hopper filling the chamber with sand during the sand shot. The flowability of green sand is mostly governed by the amount of water and bentonite which both decrease it. The flowability and the internal forces thus control how well you can fill a complex mold geom-etry in which...

Grain refinement of permanent mold cast copper base alloys. Final report

Energy Technology Data Exchange (ETDEWEB)

Sadayappan, M.; Thomson, J. P.; Elboujdaini, M.; Gu, G. Ping; Sahoo, M.

2004-04-29

Grain refinement behavior of copper alloys cast in permanent molds was investigated. This is one of the least studied subjects in copper alloy castings. Grain refinement is not widely practiced for leaded copper alloys cast in sand molds. Aluminum bronzes and high strength yellow brasses, cast in sand and permanent molds, were usually fine grained due to the presence of more than 2% iron. Grain refinement of the most common permanent mold casting alloys, leaded yellow brass and its lead-free replacement EnviroBrass III, is not universally accepted due to the perceived problem of hard spots in finished castings and for the same reason these alloys contain very low amounts of iron. The yellow brasses and Cu-Si alloys are gaining popularity in North America due to their low lead content and amenability for permanent mold casting. These alloys are prone to hot tearing in permanent mold casting. Grain refinement is one of the solutions for reducing this problem. However, to use this technique it is necessary to understand the mechanism of grain refinement and other issues involved in the process. The following issues were studied during this three year project funded by the US Department of Energy and the copper casting industry: (1) Effect of alloying additions on the grain size of Cu-Zn alloys and their interaction with grain refiners; (2) Effect of two grain refining elements, boron and zirconium, on the grain size of four copper alloys, yellow brass, EnviroBrass II, silicon brass and silicon bronze and the duration of their effect (fading); (3) Prediction of grain refinement using cooling curve analysis and use of this method as an on-line quality control tool; (4) Hard spot formation in yellow brass and EnviroBrass due to grain refinement; (5) Corrosion resistance of the grain refined alloys; (6) Transfer the technology to permanent mold casting foundries; It was found that alloying elements such as tin and zinc do not change the grain size of Cu-Zn alloys

Performance of U-Pu-Zr fuel cast into zirconium molds

International Nuclear Information System (INIS)

Crawford, D.C.; Lahm, C.E.; Tsai, H.

1992-01-01

Current fabrication techniques for the integral fast reactor (IFR) fuel utilize injection casting into quartz molds after reprocessing in the IFR fuel cycle facility. The quartz molds are destroyed during the fuel demolding process, and the quartz residue must therefore be treated as contaminated waste. Alternatively, if the fuel can be cast into molds that remain as part of the fuel slugs (i.e., if the fuel can be left inside the molds for irradiation), then the quartz mold contribution to the waste stream can be eliminated. This possibility is being addresssed in an ongoing effort to evaluate the irradiation performance of fuel cast into zirconium sheaths rather than quartz molds. Zirconium was chosen as the sheath material because it is the component of the U-Pu-Zr fuel alloy that raises the alloy solidus temperatures and provides resistance to fuel-cladding chemical interaction (FCCI)

Effect of heat treatment on corrosion behavior of low pressure sand cast Mg-10Gd-3Y-0.5Zr alloys

Directory of Open Access Journals (Sweden)

Qian-qian Wu

2016-07-01

Full Text Available The corrosion behaviors of low-pressure sand cast Mg-10Gd-3Y-0.5Zr (wt.% alloys in as-cast, solution treated (T4 and aged (T6 conditions were studied by means of immersion test and electrochemical measurements in 5wt.% NaCl solution saturated with Mg(OH2. It was observed that the corrosion rate in the T4 condition was lower than that of the as-cast and T6 conditions by both sand casting and permanent mold casting with the same order of as-cast>T6>T4; while the corrosion resistance of the permanent mold casting is superior to the sand casting. The morphologies of the corrosion products are similar porous structures consisting of tiny erect flakes perpendicular to the corroded surface of the alloy, irrespective of the heat treatment conditions. Especially, the corrosion film in T4 condition is more compact than that in the other two conditions. In addition, the severer corrosion happening to the as-cast condition is correlated with the galvanic corrosion between the matrix and the eutectic compounds; while improved corrosion resistance for the T4 and T6 conditions is ascribed to the dissolution of the secondary eutectic compounds. The measured corrosion current densities of Mg-10Gd-3Y-0.5Zr alloys in as-cast, T4, and T6 conditions are 36 μA·cm-2, 10 μA·cm-2, and 33 μA·cm-2, respectively. The proposed equivalent circuit [Rs(CPE1(Rt(RfCPE2] by Zview software matches well with the tested electrochemical impedance spectra (EIS data.

Structural and compositional analysis of a casting mold sherd from ancient China.

Science.gov (United States)

Zong, Yunbing; Yao, Shengkun; Lang, Jianfeng; Chen, Xuexiang; Fan, Jiadong; Sun, Zhibin; Duan, Xiulan; Li, Nannan; Fang, Hui; Zhou, Guangzhao; Xiao, Tiqiao; Li, Aiguo; Jiang, Huaidong

2017-01-01

Casting had symbolic significance and was strictly controlled in the Shang dynasty of ancient China. Vessel casting was mainly distributed around the Shang capital, Yin Ruins, which indicates a rigorous centralization of authority. Thus, for a casting mold to be excavated far from the capital region is rare. In addition to some bronze vessel molds excavated at the Buyao Village site, another key discovery of a bronze vessel mold occurred at Daxinzhuang. The Daxinzhuang site was a core area in the east of Shang state and is an important site to study the eastward expansion of the Shang. Here, combining synchrotron X-rays and other physicochemical analysis methods, nondestructive three-dimensional structure imaging and different elemental analyses were conducted on this mold sherd. Through high penetration X-ray tomography, we obtained insights on the internal structure and discovered some pores. We infer that the generation of pores inside the casting mold sherd was used to enhance air permeability during casting. Furthermore, we suppose that the decorative patterns on the surface were carved and not pasted onto it. Considering the previous compositional studies of bronze vessels, the copper and iron elements were analyzed by different methods. Unexpectedly, a larger amount of iron than of copper was detected on the surface. According to the data analysis and archaeological context, the source of iron on the casting mold sherd could be attributed to local soil contamination. A refined compositional analysis confirms that this casting mold was fabricated locally and used for bronze casting.

Structural and compositional analysis of a casting mold sherd from ancient China.

Directory of Open Access Journals (Sweden)

Yunbing Zong

Full Text Available Casting had symbolic significance and was strictly controlled in the Shang dynasty of ancient China. Vessel casting was mainly distributed around the Shang capital, Yin Ruins, which indicates a rigorous centralization of authority. Thus, for a casting mold to be excavated far from the capital region is rare. In addition to some bronze vessel molds excavated at the Buyao Village site, another key discovery of a bronze vessel mold occurred at Daxinzhuang. The Daxinzhuang site was a core area in the east of Shang state and is an important site to study the eastward expansion of the Shang. Here, combining synchrotron X-rays and other physicochemical analysis methods, nondestructive three-dimensional structure imaging and different elemental analyses were conducted on this mold sherd. Through high penetration X-ray tomography, we obtained insights on the internal structure and discovered some pores. We infer that the generation of pores inside the casting mold sherd was used to enhance air permeability during casting. Furthermore, we suppose that the decorative patterns on the surface were carved and not pasted onto it. Considering the previous compositional studies of bronze vessels, the copper and iron elements were analyzed by different methods. Unexpectedly, a larger amount of iron than of copper was detected on the surface. According to the data analysis and archaeological context, the source of iron on the casting mold sherd could be attributed to local soil contamination. A refined compositional analysis confirms that this casting mold was fabricated locally and used for bronze casting.

''Heat Transfer at the Mold-Metal Interface in Permanent Mold Casting of Aluminum Alloys'' Final Project Report; FINAL

International Nuclear Information System (INIS)

Pehlke, R. D.; Cookson, John M.; Shouwei Hao; Prasad Krishna; Bilkey, Kevin T.

2001-01-01

This project on heat transfer coefficients in metal permanent mold casting has been conducted in three areas. They are the theoretical study at the University of Michigan, the experimental investigation of squeeze casting at CMI-Tech Center (Now Hayes-Lemmerz Technical Center) and the experimental investigation of low pressure permanent mold casting at Amcast Automotive

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.

Precision casting into disposable ceramic mold – a high efficiency method of production of castings of irregular shape

OpenAIRE

Уваров, Б. И.; Лущик, П. Е.; Андриц, А. А.; Долгий, Л. П.; Заблоцкий, А. В.

2016-01-01

The article shows the advantages and disadvantages of precision casting into disposable ceramic molds. The high quality shaped castings produced by modernized ceramic molding process are proved the reliability and prospects of this advanced technology.

PRECISION CASTING INTO DISPOSABLE CERAMIC MOLD – A HIGH EFFICIENCY METHOD OF PRODUCTION OF CASTINGS OF IRREGULAR SHAPE

Directory of Open Access Journals (Sweden)

B. I. Uvarov

2016-01-01

Full Text Available The article shows the advantages and disadvantages of precision casting into disposable ceramic molds. The high quality shaped castings produced by modernized ceramic molding process are proved the reliability and prospects of this advanced technology.

Measurement of casting parameters in ZnAlCu3 molds created by additive technology

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S. Medić

2016-10-01

Full Text Available This paper examines the parameters of casting ZnAl4Cu3 alloy (volume, castability, density and occupancy of the mold in mold made additive technology. Molds made by additive technology are: cheaper in production of a small number of castings, geometrically more accurate and faster made. From obtained results of this paper it is clearly seen that printed mold must be protected with thermal coating because liquid adhesive of powder otherwise evaporates during casting and creates additional moisture in the mold, as it was noted.

3D scanning based mold correction for planar and cylindrical parts in aluminum die casting

Directory of Open Access Journals (Sweden)

Takashi Seno

2015-04-01

Full Text Available Aluminum die casting is an important manufacturing process for mechanical components. Die casting is known to be more accurate than other types of casting; however, post-machining is usually necessary to achieve the required accuracy. The goal of this investigation is to develop machining- free aluminum die casting. Improvement of the accuracy of planar and cylindrical parts is expected by correcting metal molds. In the proposed method, the shape of cast aluminum made with the initial metal molds is measured by 3D scanning. The 3D scan data includes information about deformations that occur during casting. Therefore, it is possible to estimate the deformation and correction amounts by comparing 3D scan data with product computer-aided design (CAD data. We corrected planar and cylindrical parts of the CAD data for the mold. In addition, we corrected the planar part of the metal mold using the corrected mold data. The effectiveness of the proposed method is demonstrated by evaluating the accuracy improvement of the cast aluminum made with the corrected mold.

40 CFR Appendix - Alternative Organic HAP Emissions Limits for Open Molding, Centrifugal Casting, and SMC...

Science.gov (United States)

2010-07-01

... Limits for Open Molding, Centrifugal Casting, and SMC Manufacturing Operations Where the Standards Are..., Table 5 Alternative Organic HAP Emissions Limits for Open Molding, Centrifugal Casting, and SMC... casting—CR/HS 3,4 A vent system that moves heated air through the mold 27 lb/ton. 8. Centrifugal casting...

Analysis of cracking in glass molds made of cast iron

Science.gov (United States)

Leushin, I. O.; Chistyakov, D. G.

2014-09-01

The cracking in the parts of cast iron molds intended for glass is considered, and this cracking substantially affects the operation of glass-blowing equipment, maintainability, and the replacement of mold sets. The processes that cause cracking in the parts of glass molds and initiate crack growth are studied.

Emission of BTEX and PAHs from molding sands with furan cold setting resins containing different contents of free furfuryl alcohol during production of cast iron

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Mariusz Holtzer

2015-11-01

Full Text Available At present, furan resin is the largest selling no-bake system of moulding sands. The most commonly used furan no-bake binders (FNB are condensation products of furfuryl alcohol (FA urea, formaldehyde and phenol. They are generally cured by exposure to organic sulfonic acids. FNB provide excellent mold and core strength, cure rapidly and allow the sand to be reclaimed at fairly high yields, generally 75%-80%, especially in applications where due allowance is made for the need to keep total sulfur content below 0.1%. However, due to probable carcinogenic properties of furfuryl alcohol, the EU Directive limits the content of this substance (in a monomer form in resin to 25%. The classification of furfuryl alcohol and the resulting furan resin products has changed from "harmful" to "toxic" by inhalation? The aim of this study was to determine the effect of free furfuryl alcohol content in the resin on the emission of harmful substances from the BTEX (Benzene Toluene Ethylbenzene & Xylene and PAHs (polycyclic aromatic hydrocarbon group exposed to high temperature and how it affects the emissions allowance of reclaimed sand in the matrix. Three resins from a leading manufacturer were examined, which contain a free furfuryl alcohol content of 71%-72%, about 50% and < 25%, respectively. The hardener for each resin was 65% aqueous solution of paratoluenesulfonic acid. Tests were carried out in semi-industrial conditions where liquid cast-iron was poured into sample sand mold at 1,350 ìC. The matrix of the studied sands was reclaimed in the amount of 0, 50%, 100%, respectively. With the increase of free furfuryl alcohol content, the volume of evolved gases decreased. For all resins the main component from the BTEX group dominating in the emitted gases was benzene; however toluene also appeared in the amount of a few percentages. In contrast, ethylbenzene and xylenes occurred only in the gases emitted from resin-bonded sands with the largest furfuryl

Heat Transfer Coefficient at Cast-Mold Interface During Centrifugal Casting: Calculation of Air Gap

Science.gov (United States)

Bohacek, Jan; Kharicha, Abdellah; Ludwig, Andreas; Wu, Menghuai; Karimi-Sibaki, Ebrahim

2018-06-01

During centrifugal casting, the thermal resistance at the cast-mold interface represents a main blockage mechanism for heat transfer. In addition to the refractory coating, an air gap begins to form due to the shrinkage of the casting and the mold expansion, under the continuous influence of strong centrifugal forces. Here, the heat transfer coefficient at the cast-mold interface h has been determined from calculations of the air gap thickness d a based on a plane stress model taking into account thermoelastic stresses, centrifugal forces, plastic deformations, and a temperature-dependent Young's modulus. The numerical approach proposed here is rather novel and tries to offer an alternative to the empirical formulas usually used in numerical simulations for a description of a time-dependent heat transfer coefficient h. Several numerical tests were performed for different coating thicknesses d C, rotation rates Ω, and temperatures of solidus T sol. Results demonstrated that the scenario at the interface is unique for each set of parameters, hindering the possibility of employing empirical formulas without a preceding experiment being performed. Initial values of h are simply equivalent to the ratio of the coating thermal conductivity and its thickness ( 1000 Wm-2 K-1). Later, when the air gap is formed, h drops exponentially to values at least one order of magnitude smaller ( 100 Wm-2 K-1).

Casting dimensional control and fatigue life prediction for permanent mold casting dies. Technical progress report, September 29, 1993-- September 30, 1994

Energy Technology Data Exchange (ETDEWEB)

NONE

1994-11-01

First year efforts as part of a three year program to address metal casting dimensional control and fatigue life prediction for permanent mold casting dies are described. Procedures have been developed and implemented to collect dimensional variability data from production steel castings. The influence of process variation and casting geometry variables on dimensional tolerances have been investigated. Preliminary results have shown that these factors have a significant influence on dimensional variability, although this variability is considerably less than the variability indicated in current tolerance standards. Gage repeatability and reproducibility testing must precede dimensional studies to insure that measurement system errors are acceptably small. Also initial efforts leading to the development and validation of a CAD/CAE model to predict the thermal fatigue life of permanent molds for aluminum castings are described. An appropriate thermomechanical property database for metal, mold and coating materials has been constructed. A finite element model has been developed to simulate the mold temperature distribution during repeated casting cycles. Initial validation trials have indicated the validity of the temperature distribution model developed.

The casting of western sculpture during the XIXth century: sand casting versus lost wax casting

NARCIS (Netherlands)

Beentjes, T.P.C.

2014-01-01

This paper will discuss research into bronze casting techniques as practiced during the XIXth and early XXth century. Both natural sand casting (fonte au sable naturel) and lost wax casting (fonte à la cire perdue) were employed during this period and sometimes rivalled for commissions. Before the

The influence of microwave heating and water glass kind on the properties of molding sands

Directory of Open Access Journals (Sweden)

K. Granat

2008-03-01

Full Text Available This work presents rcsults of research on thc influcncc of microwave heating time on the process of hardening of warcr glass moldingsands. Essential influence of this drying process on basic properties such as: cornprcssion, bcnding mind tcnsitc strcng~h as well aspcrrneabili~y and war resistance, has bccn found. It has bccn proved, that at1 thc investigated sorts of sodium water glass could be uscd asbinding material of molding sands intended for curing with the microwave process healing. It has bccn found, while analyzing the rcsultsof property studics or microwavc heated molding sands with 2.5% addition of water glass, that aIl available on the markct kinds of thisbinding agent (inctuding the most frequently uscd in foundry 145 and 149 kinds after microwave heating guarantee very goodcompression, bending and tensile strength as well as permeability and wcar resistance. Moroovcr, it has bccn dctcrmined that the optimalcuring powcr of molding sands containing various kinds of water gIass is 560 W. AII values exceeding this rcsult in stabilization of basicpropcrtics of molding sands. The use of microwave curing of water glass molding sands results in a significant decrease of hardeningprocess time. full stabilization of molding sands as well as much lower energy consumption.

Casting Ductile Iron in Layer Moulds Made from Ecological Sands

Directory of Open Access Journals (Sweden)

M. Rączka

2012-09-01

Full Text Available The article contains the results of tests performed under the target project in Hardtop Foundry Charsznica.The objective of the tests and studies was to develop a technology of making high-quality ductile iron castings, combined witheffective means of environmental protection. The studies presented in this article related to castings weighing from 1 to 300 kg made from ductile iron of grades 400-15 and 500-7, using two-layer moulds, where the facing and core sand was the sand with an alkaline organic binder, while backing sand was the sand with an inorganic geopolymer binder.A simplified method of sand reclamation was applied with possible reuse of the reclaim as an addition to the backing sand. The castiron spheroidising treatment and inoculation were selected taking into account the specific conditions of Hardtop Foundry. A pilot batch of castings was made, testing the gating and feeding systems and using exothermic sleeves on risers. The study confirmed the validity of the adopted concept of making ductile iron castings in layer moulds, while maintaining the content of sand with an organic binder at a level of maximum 15%.

Analysis of Mold Friction in a Continuous Casting Using Wavelet Transform

Science.gov (United States)

Ma, Yong; Fang, Bohan; Ding, Qiqi; Wang, Fangyin

2018-04-01

Mold friction (MDF) is an important parameter reflecting the lubrication condition between the initial shell and the mold during continuous casting. In this article, based on practical MDF from the slab continuous casting driven by a mechanical vibration device, the characteristics of friction were analyzed by continuous wavelet transform (CWT) and discrete wavelet transform (DWT) in different casting conditions, such as normal casting, level fluctuation, and alarming of the temperature measurement system. The results show that the CWT of friction accurately captures the subtle changes in friction force, such as the periodic characteristic of MDF during normal casting and the disordered feature of MDF during level fluctuation. Most important, the results capture the occurrence of abnormal casting and display the friction frequency characteristics at this abnormal time. In addition, in this article, there are some abnormal casting conditions, and the friction signal is stable until there is a sudden large change when abnormal casting, such as split breakout and submerged entry nozzle breakage, occurs. The DWT has a good ability to capture the friction characteristics for such abnormal situations. In particular, the potential abnormal features of MDF were presented in advance, which provides strong support for identifying abnormal casting and even preventing abnormal casting.

Self-supported ceramic substrates with directional porosity by mold freeze casting

DEFF Research Database (Denmark)

Gurauskis, Jonas; Graves, Christopher R.; Moreno, R.

2016-01-01

in a mold and applying directional freeze casting. Use of optimized suspension, cryoprotector additive and mold proved to deliver defect free ceramic films with high dimensional control. Microstructure analysis demonstrated the formation of desirable aligned porosity at macro-structural scale and resulted...... to be highly dependent on colloidal behaviour and freeze casting conditions. Manufactured green films were joined by lamination at room temperature and sintered to obtain symmetrical cells consisting of two porous self-supported substrate electrodes (∼420 μm) and dense yttria stabilized zirconia electrolyte...

Integrated System of Thermal/Dimensional Analysis for Quality Control of Metallic Melt and Ductile Iron Casting Solidification

Science.gov (United States)

Stan, Stelian; Chisamera, Mihai; Riposan, Iulian; Neacsu, Loredana; Cojocaru, Ana Maria; Stan, Iuliana

2018-03-01

The main objective of the present work is to introduce a specific experimental instrument and technique for simultaneously evaluating cooling curves and expansion or contraction of cast metals during solidification. Contraction/expansion analysis illustrates the solidification parameters progression, according to the molten cast iron characteristics, which are dependent on the melting procedure and applied metallurgical treatments, mold media rigidity and thermal behavior [heat transfer parameters]. The first part of the paper summarizes the performance of this two-mold device. Its function is illustrated by representative shrinkage tendency results in ductile cast iron as affected by mold rigidity (green sand and furan resin sand molds) and inoculant type (FeSi-based alloys), published in part previously. The second part of the paper illustrates an application of this equipment adapted for commercial foundry use. It conducts thermal analysis and volume change measurements in a single ceramic cup so that mold media as well as solidification conditions are constants, with cast iron quality as the variable. Experiments compared gray and ductile cast iron solidification patterns. Gray iron castings are characterized by higher undercooling at the beginning and at the end of solidification and lower graphitic expansion. Typically, ductile cast iron exhibits higher graphitic, initial expansion, conducive for shrinkage formation in soft molds.

Application of heat pipe technology in permanent mold casting of nonferrous alloys

Science.gov (United States)

Elalem, Kaled

The issue of mold cooling is one, which presents a foundry with a dilemma. On the one hand; the use of air for cooling is safe and practical, however, it is not very effective and high cost. On the other hand, water-cooling can be very effective but it raises serious concerns about safety, especially with a metal such as magnesium. An alternative option that is being developed at McGill University uses heat pipe technology to carry out the cooling. The experimental program consisted of designing a permanent mold to produce AZ91E magnesium alloy and A356 aluminum alloy castings with shrinkage defects. Heat pipes were then used to reduce these defects. The heat pipes used in this work are novel and are patent pending. They are referred to as McGill Heat Pipes. Computer modeling was used extensively in designing the mold and the heat pipes. Final designs for the mold and the heat pipes were chosen based on the modeling results. Laboratory tests of the heat pipe were performed before conducting the actual experimental plan. The laboratory testing results verified the excellent performance of the heat pipes as anticipated by the model. An industrial mold made of H13 tool steel was constructed to cast nonferrous alloys. The heat pipes were installed and initial testing and actual industrial trials were conducted. This is the first time where a McGill heat pipe was used in an industrial permanent mold casting process for nonferrous alloys. The effects of cooling using heat pipes on AZ91E and A356 were evaluated using computer modeling and experimental trials. Microstructural analyses were conducted to measure the secondary dendrite arm spacing, SDAS, and the grain size to evaluate the cooling effects on the castings. The modeling and the experimental results agreed quite well. The metallurgical differences between AZ91E and A356 were investigated using modeling and experimental results. Selected results from modeling, laboratory and industrial trials are presented. The

Comparison of residual stresses in sand- and chill casting of ductile cast iron wind turbine main shafts

International Nuclear Information System (INIS)

Sonne, M R; Hattel, J H; Frandsen, J O

2015-01-01

In this work, simulations of pouring, solidification and cooling, and residual stress evolution of sand and chill cast wind turbine main shafts is performed. The models are made in the commercial software MAGMAsoft. As expected, the cooling rate of the sand casting is shown to be much lower than for the chill casting, resulting in a very course microstructure. From the simulations the nodule count is found to be 17 nodules per mm 2 and 159 nodules per mm 2 for the sand and chill casting, respectively, in the critical region of the main bearing seat. This is verified from nodule counts performed on the real cast main shafts. Residual stress evaluations show an overall increase of the maximum principal stress field for the chill casting, which is expected. However, the stresses are found to be in compression on the surface of the chill cast main shaft, which is unforeseen. (paper)

Comparison of residual stresses in sand- and chill casting of ductile cast iron wind turbine main shafts

DEFF Research Database (Denmark)

Sonne, Mads Rostgaard; Frandsen, J. O.; Hattel, Jesper Henri

2015-01-01

In this work, simulations of pouring, solidification and cooling, and residual stress evolution of sand and chill cast wind turbine main shafts is performed. The models are made in the commercial software MAGMAsoft. As expected, the cooling rate of the sand casting is shown to be much lower than...... for the chill casting, resulting in a very course microstructure.From the simulations the nodule count is found to be 17 nodules per mm2 and 159 nodules permm2 for the sand and chill casting, respectively, in the critical region of the main bearing seat.This is verified from nodule counts performed on the real...... cast main shafts. Residual stressevaluations show an overall increase of the maximum principal stress field for the chill casting,which is expected. However, the stresses are found to be in compression on the surface of thechill cast main shaft, which is unforeseen....

40 CFR 63.5810 - What are my options for meeting the standards for open molding and centrifugal casting operations...

Science.gov (United States)

2010-07-01

... standards for open molding and centrifugal casting operations at new and existing sources? 63.5810 Section... § 63.5810 What are my options for meeting the standards for open molding and centrifugal casting... (d) of this section to meet the standards for open molding or centrifugal casting operations in Table...

Reusable molds for casting U-Zr alloys

International Nuclear Information System (INIS)

Chen, P.S.; Stevens, W.C.; Trybus, C.L.

1992-09-01

Refractory oxides, carbides, nitrides and sulfides were examined as mold coating materials for use in casting nuclear fuel. The molds require excellent high temperature chemical and mechanical stability combined with reasonable room temperature ductility to allow for fuel removal. Coatings were applied onto quartz and refractory metal coupons using various techniques. Sessile drop tests employing molten U-10%Zr (by weight) at 1550 degrees C were used to characterize coating performance. Results indicate that NbC, TiN, and Y 2 O 3 were non-wetting with U-10%Zr. However, only the Y 2 O 3 coating completely prevented adhesion of the fuel. The paper describes coating methods and details of the sessile drop experiments

Interim Report on Mixing During the Casting of LEU-10Mo Plates in the Triple Plate Molds

Energy Technology Data Exchange (ETDEWEB)

Aikin, Jr., Robert M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2017-04-12

LEU-10%Mo castings are commonly produced by down blending unalloyed HEU with a DU-12.7%Mo master-alloy. This work uses process modeling to provide insight into the mixing of the unalloyed uranium and U-Mo master alloy during melting and mold filling of a triple plate casting. Two different sets of situations are considered: (1) mixing during mold filling from a compositionally stratified crucible and (2) convective mixing of a compositionally stratified crucible during mold heating. The mold filling simulations are performed on the original Y-12 triple plate mold and the horizontal triple plate mold.

Changes of gas pressure in sand mould during cast iron pouring

Directory of Open Access Journals (Sweden)

J. Mocek

2011-10-01

Full Text Available The paper presents a test method developed to measure changes of gas pressure in sand moulds during manufacture of iron castings. The pressure and temperature measurements were taken in the sand mould layers directly adjacent to the metal – mould interface. A test stand was described along with the measurement methodology. The sensors used allowed studying the fast-changing nature of the processes which give rise to the gas-originated casting defects. The study examined the influence of binders, clays and refining additives on the nature of the gas evolution process. The effect of the base sand type - quartz or olivine - on the nature of pressure changes was compared. The test stand design ensured the stability of technological parameters in the examined mould elements, and a repeatable process of making pilot castings. The main outcome was classification of sand mixtures in terms of pressure occurring during pouring of iron castings. The obtained results confirm the usefulness of the described method for testing gas pressure occurrence in a sand mould.

Potensi Pasir Lokal Tanjung Bintang Pada Aluminium Sand Casting Terhadap Porositas Produk Hasil Cor Aluminium

OpenAIRE

Hendronursito, Yusup; Prayanda, Yogi

2016-01-01

Green sand is one of the most important components in the process of metal casting. The sand in Indonesia region is varied level of subtlety, size of sand, and shape of sand. Green sand used in the process of metal casting is possible can affect the quality of casting product. This aims to determine the potential of Tanjung Bintang sand as green sand and the quality of the product in terms of porosity defects. The research was conducted by varying sand river from Tanjung Bintang and sand from...

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%.

Graphite nodules in fatigue-tested cast iron characterized in 2D and 3D

DEFF Research Database (Denmark)

Mukherjee, Krishnendu; Fæster, Søren; Hansen, Niels

2017-01-01

Thick-walled ductile iron casts have been studied by applying (i) cooling rate calculations by FVM, (ii) microstructural characterization by 2D SEM and 3D X-ray tomography techniques and (iii) fatigue testing of samples drawn from components cast in sand molds and metal molds. An analysis has shown...... correlations between cooling rate, structure and fatigue strengths demonstrating the benefit of 3D structural characterization to identify possible causes of premature fatigue failure of ductile cast iron....

Evolution of the gas atmosphere during filing the sand moulds with iron alloys

Directory of Open Access Journals (Sweden)

J. Mocek

2009-10-01

Full Text Available Evolution of atmosphere of the mould cavity when pouring the cast iron has been analyzed. It was find that in dry sand mold the cavity is filled by air throughout the casting time. In green sand the air is removed by the water vapor the hydrogen or carbon oxides formed in contact with the liquid metal. The theoretical results have been confirmed experimentally.

Die casting copper motor rotors: mold materials and processing for cost-effective manufacturing

Energy Technology Data Exchange (ETDEWEB)

Peters, D.T.; Cowie, J.G.; Brush, E.F. Jr.

2000-07-01

This project seeks to demonstrate mold materials for copper pressure die-casting that are cost-effective and practical for production use in die-casting copper motor rotors. The incorporation of die-cast copper for conductor bars and end rings of the induction motor in place of aluminum would result in attractive improvements in motor energy efficiency through reductions in motor losses ranging from 15% to 20%. Die-cast motor rotors are produced in aluminum today because rotor fabrication by pressure die-casting is an established practice. Lack of a durable and cost-effective mold material has been the technical barrier preventing manufacture of the die-cast copper rotor. This project tested H-13 steel die inserts that establish the baseline. Nickel-, tungsten-, and molybdenum-based high temperature alloys were extensively tested. Results indicate that substantially extended die life is possible using high temperature die materials, pre-heated and operated at elevated temperatures. Pre-heating and high operating temperatures were shown to be critical in extending the die life by decreasing the cyclic stresses associated with thermal expansion. Extended die life provides the opportunity for economically viable copper motor rotor die-casting. (orig.)

Quality Management and Control of Low Pressure Cast Aluminum Alloy

Science.gov (United States)

Zhang, Dianxi; Zhang, Yanbo; Yang, Xiufan; Chen, Zhaosong; Jiang, Zelan

2018-01-01

This paper briefly reviews the history of low pressure casting and summarizes the major production processes of low pressure casting. It briefly introduces the quality management and control of low pressure cast aluminum alloy. The main processes include are: preparation of raw materials, Melting, refining, physical and chemical analysis, K-mode inspection, sand core, mold, heat treatment and so on.

Based on database and asp.net technologies, a web platform of scientific data in the casting forces on the mold-fi lling behavior of titanium melts in vertically rotating molds

Directory of Open Access Journals (Sweden)

Xu Daming

2008-11-01

Full Text Available The vertical centrifugal-casting technique is widely used in the manufacture of various irregularlyshaped castings of advanced structural alloys with thin walls, complex shapes and/or large sizes. These castings are used in the increasing applications in aero-space/aviation industries, human teeth/bone repairs with nearnet shaped components, etc. In a vertically rotating casting system, the mold-filling processes of alloy melts, coupled with solidifi cation-heat transfer, may be much more complicated, because they are driven simultaneously by gravity, centrifugal and Coriolis forces. In the present work, an N-S/VOF-equations-based model, solved using a SOLA-VOF algorithm, under a rotating coordinate system was applied to numerically investigate the impacts of centrifugal and Coriolis forces on metallic melt mold-fi lling processes in different vertical centrifugal-casting configurations with different mold-rotation rates using an authors’ computer-codes system. The computational results show that the Coriolis force may cause remarkable variations in the fl ow patterns in the casting-part-cavities of a large horizontal-section area and directly connected to the sprue via a short ingate in a vertical centrifugalcasting process. A “turn-back” mold-filling technique, which only takes advantage of the centrifugal force in a transient rotating melt system, has been confi rmed to be a rational centrifugal-casting process in order to achieve smooth and layer-by-layer casting-cavities-fi lling control. The simulated mold-fi lling processes of Ti-6Al-4V alloy melt, in a vertical centrifugal-casting system with horizontally-connected plate-casting cavities, show reasonable agreement with experimental results from the literature.

Designing a combined casting mold for manufacture of a gasoline centrifugal pump body using CAD/CAM-systems

Science.gov (United States)

Galin, N. E.; Ogol, I. I.; Chervach, Yu B.; Dammer, V. Kh; Ru, Jia Hong

2017-02-01

The present paper examines designing of a combined casting mold for manufacture of a gasoline centrifugal pump body. The paper offers technological solutions for obtaining high quality castings at the testing stage of the finished mold. The paper is intended for practical use and prepared by order of JSC ‘Tomsk Electrical Engineering Plant’ using software and equipment of the department ‘Technologies of Computer-Aided Machinery Manufacturing’ of the Tomsk Polytechnic University (TPU) under the economic contract within state import substitution program. In preparing the paper, CAD/CAM-systems KOMPAS-3D and PowerMILL were used. In 2015, the designed casting mold was introduced into the production process at JSC ‘Tomsk Electrical Engineering Plant’.

The diffusion of sulphur from moulding sand to cast and methods of its elimination

Directory of Open Access Journals (Sweden)

M. Hosadyna

2009-10-01

Full Text Available The care of high quality castings requires taking into account the possible negative influence of decomposition products of moulding and core sands on the structure of castings produced. Such products are emitted both from the sands of I generation, meaning sands bound by bentonite, especially those containing carbon forming additives, as well as from the sands of II generation, meaning the sands with the binding materials or even the sands without any binders, such as the forms produced by using the LOST FOAM technology. The literature often refers to the negative effects of nitrogen emitted from the sands with the urea resins on the tendency to create surface defects. That is why the aim of this study was to assess the degree of sulphur diffusion to the ferroalloy castings and the proposal of its limitation.

Application of digital pattern-less molding technology to produce art casting

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Chen Li1

2014-11-01

Full Text Available Compared with the conventional casting process, digital pattern-less casting technology has many advantages such as good machining accuracy, a short processing cycle, and low production cost. It is a new rapid manufacturing technology for castings, integrated with CAD/CAM, casting, CNC machining and many other advanced technologies. With this digital casting technology, no pattern is needed for making molds; it is precise, flexible, and green. Usually, art castings have complex structures and are made in small batches or even made in a single-piece, especially for large-sized art castings. So it has the shortcomings of high cost, low efficiency and long time for making a pattern to produce art castings with the conventional casting processes. However, the digital pattern-less casting technology can be applied to fabricate art castings, since it can greatly shorten the manufacturing cycle and lower the production cost, thus having a very good prospect. In this study, based on the digital pattern-less casting technology, a plaque casting with artistic Chinese characters (a Chinese poem was designed and manufactured, and the production process was demonstrated in detail.

Effect of investment type and mold temperature on casting accuracy and titanium-ceramic bond.

Science.gov (United States)

Leal, Mônica Barbosa; Pagnano, Valéria Oliveira; Bezzon, Osvaldo Luiz

2013-01-01

This study evaluated the casting accuracy of crown margins and metal-ceramic shear bond strength (SBS) of pure titanium injected into casting molds made using 2 investment types at 3 mold temperatures. Sixty crown (30-degree beveled finish line) and 60 cylinder (5mm diameter × 8mm high) patterns were divided into 6 groups (n=10), and cast using a phosphate-bonded investment (P) and a magnesium oxide-bonded investment (U), at 400°C (groups P400 and U400), 550°C (groups P550 and U550) and 700°C (groups P700 and U700) mold temperatures. Crown margins were recorded in impression material, the degree of marginal rounding was measured and margin length deficiencies (µm) were calculated. Titanium-ceramic specimens were prepared using Triceram ceramic (2mm high) and SBS was tested. Failure modes were assessed by optical microscopy. Data were subjected to two-way ANOVA and Tukey's HSD test (α=0.05). For casting accuracy, expressed by marginal deficiency (µm), investment U provided more accurate results (64 ± 11) than P (81 ± 23) (pcasting accuracy for U700 (55 ± 7) and worse for P700 (109 ± 18). Casting accuracy at 700°C (82 ± 31) was significantly different from 400°C (69 ± 9) and 550°C (68 ± 9) (pcasting accuracy than investment P. The SBS was similar for all combinations of investments and temperatures.

In-Situ Real Time Monitoring and Control of Mold Making and Filling Processes: Final Report

Energy Technology Data Exchange (ETDEWEB)

Mohamed Abdelrahman; Kenneth Currie

2010-12-22

This project presents a model for addressing several objectives envisioned by the metal casting industries through the integration of research and educational components. It provides an innovative approach to introduce technologies for real time characterization of sand molds, lost foam patterns and monitoring of the mold filling process. The technology developed will enable better control over the casting process. It is expected to reduce scrap and variance in the casting quality. A strong educational component is integrated into the research plan to utilize increased awareness of the industry professional, the potential benefits of the developed technology, and the potential benefits of cross cutting technologies.

Influence of gating design on microstructure and fluidity of thin sections AA320.0 cast hypo-eutectic Al-Si alloy

Science.gov (United States)

Ramadan, Mohamed

2018-05-01

Influence of gating design especially number of ingrates on microstructure and fluidity of thin sections of 2, 4, 6 mm AA320.0 cast hypo-eutectic Al-Si alloy was evaluated for sand casting molding technique. Increasing the number of ingates improves the microstructe to be fine and more globular. About 87 μm of α-Al grain size, 0.6 α-Al grain sphericity and 37 μm dendrite arm spacing DAS are achieved by using 4 ingates in gating system. Increasing the number of ingates up to 3 increases hardness, filling area and related fluditiy of all cast samples. The minimum thickness of 2.5 mm for each ingate should be considered in order to successfully production of high quality light weight thin sections castings in sand mold.

Hot-tearing of multicomponent Al-Cu alloys based on casting load measurements in a constrained permanent mold

Energy Technology Data Exchange (ETDEWEB)

Sabau, Adrian S [ORNL; Mirmiran, Seyed [Fiat Chrysler Automobiles North America; Glaspie, Christopher [Fiat Chrysler Automobiles North America; Li, Shimin [Worcester Polytechnic Institute (WPI), MA; Apelian, Diran [Worcester Polytechnic Institute (WPI), MA; Shyam, Amit [ORNL; Haynes, James A [ORNL; Rodriguez, Andres [Nemak, Garza Garcia, N.L., Mexico

2017-01-01

Hot-tearing is a major casting defect that is often difficult to characterize, especially for multicomponent Al alloys used for cylinder head castings. The susceptibility of multicomponent Al-Cu alloys to hot-tearing during permanent mold casting was investigated using a constrained permanent mold in which the load and displacement was measured. The experimental results for hot tearing susceptibility are compared with those obtained from a hot-tearing criterion based temperature range evaluated at fraction solids of 0.87 and 0.94. The Cu composition was varied from approximately 5 to 8 pct. (weight). Casting experiments were conducted without grain refining. The measured load during casting can be used to indicate the severity of hot tearing. However, when small hot-tears are present, the load variation cannot be used to detect and assess hot-tearing susceptibility.

Effect of Flow Rate Controller on Liquid Steel Flow in Continuous Casting Mold using Numerical Modeling

Science.gov (United States)

Gursoy, Kadir Ali; Yavuz, Mehmet Metin

2014-11-01

In continuous casting operation of steel, the flow through tundish to the mold can be controlled by different flow rate control systems including stopper rod and slide-gate. Ladle changes in continuous casting machines result in liquid steel level changes in tundishes. During this transient event of production, the flow rate controller opening is increased to reduce the pressure drop across the opening which helps to keep the mass flow rate at the desired level for the reduced liquid steel level in tundish. In the present study, computational fluid dynamic (CFD) models are developed to investigate the effect of flow rate controller on mold flow structure, and particularly to understand the effect of flow controller opening on meniscus flow. First, a detailed validation of the CFD models is conducted using available experimental data and the performances of different turbulence models are compared. Then, the constant throughput casting operations for different flow rate controller openings are simulated to quantify the opening effect on meniscus region. The results indicate that the meniscus velocities are significantly affected by the flow rate controller and its opening level. The steady state operations, specified as constant throughput casting, do not provide the same mold flow if the controller opening is altered. Thus, for quality and castability purposes, adjusting the flow controller opening to obtain the fixed mold flow structure is proposed. Supported by Middle East Technical University (METU) BAP (Scientific Research Projects) Coordination.

An adaptive neuro-fuzzy controller for mold level control in continuous casting

International Nuclear Information System (INIS)

Zolghadri Jahromi, M.; Abolhassan Tash, F.

2001-01-01

Mold variations in continuous casting are believed to be the main cause of surface defects in the final product. Although a Pid controller is well capable of controlling the level under normal conditions, it cannot prevent large variations of mold level when a disturbance occurs in the form of nozzle unclogging. In this paper, dual controller architecture is presented, a Pid controller is used as the main controller of the plant and an adaptive neuro-fuzzy controller is used as an auxiliary controller to help the Pid during disturbed phases. The control is passed back to the Pid controller after the disturbance is being dealt with. Simulation results prove the effectiveness of this control strategy in reducing mold level variations during the unclogging period

Effect of preparation variables of plaster molds for slip casting of sanitary ware

Directory of Open Access Journals (Sweden)

Rafael E. Ochoa

2017-11-01

Full Text Available A full factorial design was used to evaluate the effect of various preparation conditions for making plaster molds for slip casting of sanitary ware. We investigated the relationships between the processing conditions, microstructure, and final properties of the plaster molds. The results showed that the rheological behavior, and hence, the time during which the plaster suspension is pourable for making the plaster molds (before an important increase in viscosity due to the precipitation of gypsum crystals were dependent on the preparation conditions. Variations in the chemical composition, pore size distribution, and microstructure explained the statistically significant effect of preparation variables (including the mixing time, water temperature, and water quality. Preparation conditions that promoted high initial viscosity of the plaster suspension (accelerative effect of the setting time developed less porous structure in the mold that principally increased the compressive strength (16%, deionized water instead of tap water and the casting rate (9%, water at 25 °C instead of 38 °C. According to the results are proposed optimum conditions to make the molds while avoiding unnecessary energy use. Resumen: Mediante un diseño factorial completo se evaluaron diferentes condiciones de preparación de moldes de yeso para colado tradicional de muebles sanitarios. Se investigó la relación entre procesamiento, microestructura y propiedades del molde. Los resultados mostraron que el comportamiento reológico y por lo tanto el tiempo durante el cual la suspensión de yeso se puede verter para conformar los moldes (antes de un incremento importante de viscosidad debido a la formación de cristales de yeso fueron dependientes de las condiciones de preparación. Variaciones en composición química, distribución de tamaño de poro y microestructura explicaron el efecto estadísticamente significativo de las variables de preparación (que incluyeron

Assessment Method of Overheating Degree of a Spent Moulding Sand with Organic Binder, After the Casting Process

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Dańko R.

2013-06-01

Full Text Available A proper management of sand grains of moulding sands requires knowing basic properties of the spent matrix after casting knocking out. This information is essential from the point of view of the proper performing the matrix recycling process and preparing moulding sands with reclaimed materials. The most important parameter informing on the matrix quality - in case of moulding sands with organic binders after casting knocking out - is their ignition loss. The methodology of estimating ignition loss of spent moulding sands with organic binder - after casting knocking out - developed in AGH, is presented in the paper. This method applies the simulation MAGMA software, allowing to determine this moulding sand parameter already at the stage of the production preparation.

Use of a general-purpose heat-transfer code for casting simulation

International Nuclear Information System (INIS)

Erickson, W.C.

1975-07-01

The practical use of numerical techniques in simulating casting solidification dictate that a general purpose heat transfer code be used and that results be obtained in an easy-to-analyze format. Color film plotting routines were developed for use with NASA's CINDA-3G heat transfer code; the combination of which meet the above criteria. The subroutine LQSLTR written for SINDA, the successor to CINDA-3G, was verified by comparing calculated results obtained using LQSLTR with those obtained using the specific heat method for handling the heat of fusion. Excellent agreement existed when similar data was used. When the more restrictive requirement of a 1 0 F melting range was used, comparable results were obtained. Uranium and lead rod castings were cast in instrumented graphite molds and the solidification sequence simulated using CINDA-3G. Discrepancies attributed to initial assumptions of instantaneous mold filling, uniform melt temperature, and intimate metal/mold contact were encountered. Further calculations using a model incorporating a gap between the mold and casting showed that the intimate contact assumption could not be used; a three-dimensional model also showed that the thermocouple assemblies used with the platinum--platinum-10 percent rhodium were a significant perturbation to the system. An L-shaped steel casting was simulated and the results compared to those reported in the literature. The experimental data for this casting were reproduced within the accuracy permitted by the thermal conductivity of the sand, thus demonstrating that agreement can be obtained when the mold material does not act as a chill. (U.S.)

Relationship between casting distortion, mold filling, and interfacial heat transfer. Annual technical report, September 1997 - September 1998

Energy Technology Data Exchange (ETDEWEB)

Woodbury, K.A.; Parker, J.K.; Piwonka, T.S.; Owusu, Y.

1998-10-22

In the third year of this program, the final castings necessary to evaluate the effect of casting orientation and gating in silica sand lost foam were poured and measured using a CMM machine. Interfacial heat transfer and gap formation measurements continued. However, significant problems were encountered in making accurate measurements. No consistent evidence of gap formation was found in aluminum sand casting. Initial analysis yields heat transfer values below those previously reported in the literature. The program in continuing.

Performance of U-Pu-Zr fuel cast into zirconium molds

International Nuclear Information System (INIS)

Crawford, D.C.; Lahm, C.E.; Tsai, H.

1992-10-01

U-3Zr and U-20.5Pu-3Zr were injection cast into Zr tubes, or sheaths, rather than into quartz molds and clad in 316SS. These elements and standard-cast U-l0Zr and U-IgPu-l0Zr elements were irradiated in EBR-II to 2 at.% and removed for interim examination. Measurements of axial growth at indicate that the Zr-sheathed elements exhibited significantly less axial elongation than the standard-cast elements (1.3 to 1.8% versus 4.9 to 8.1%). Fuel material extruded through the ends of the Zr sheaths. allowing the low-Zr fuel to contact the cladding in some cases. Transverse metallographic sections reveal cracks in the Zr sheath through which fuel extruded and contacted cladding. The sheath is not a sufficient barrier between fuel and cladding to reduce FCCI. and any adverse effects due to increased FCCI will be evident as the elements attain higher burnup

Focused Molding Using Adhesive Pads in Mehta Casting for Early-Onset Scoliosis.

Science.gov (United States)

Abraham, Roby; Sponseller, Paul D

2014-11-01

Prospective clinical series. To determine the effect of adhesive pads placed over the apex of scoliosis curves on curve correction 1) after the first cast and 2) after the final cast. Early-onset scoliosis is often effectively managed by serial casting. Properly localizing the apex of the molds with the cast in place is challenging. The authors explored the effectiveness of a novel technique: incorporation of adhesive pads placed over the major curve apex before Mehta casting. The 27 patients who received body casts (2000-2013) were divided into 2 groups: those without and with apical adhesive pads (5-6 layers of pads placed on the major curve's apex during casting): non-pad (NP) group (n = 12) and pad (P) group (n = 15), respectively. Groups were compared regarding the percentage of Cobb angle change from the first cast and curve correction to a Cobb angle of cast curve correction was 39% ± 18% and 56% ± 17% in the NP and P groups, respectively. Of the 26 patients out of a cast, 11 (42%) had a Cobb angle of casting were effective in increasing the amount of major curve correction from the first cast for idiopathic early-onset scoliosis and in decreasing curves to <25° at final follow-up. Copyright © 2014 Scoliosis Research Society. Published by Elsevier Inc. All rights reserved.

Structure Distribution in Precise Cast Iron Moulded on Meltable Model

Directory of Open Access Journals (Sweden)

Skrbek B.

2015-12-01

Full Text Available Topic of this work is to compare metalurgy of cast irons poured into sand moulds and into shell molds at IEG Jihlava company and from it following differencies in structures of thin- and thick-walled castings. This work is dealing with investigation and experimental measurement on surfaces and sections suitable thin- and thick-walled investment castings at IEG Jihlava. Cast irons with flake graphite (grey cast iron and cast irons with spheroidal graphite (ductile cast iron. Both mechanical and physical properties are determined using calculations from as measured values of wall thicknesses L and Lu, Vickers hardness and remanent magnetism. Measurement results are discussed, findings are formulated and methods for castings metallurgical quality improvement are recommended finally.

Compound cast product and method for producing a compound cast product

Science.gov (United States)

Meyer, Thomas N.; Viswanathan, Srinath

2002-09-17

A compound cast product is formed in a casting mold (14) having a mold cavity (16) sized and shaped to form the cast product. A plurality of injectors (24) is supported from a bottom side (26) of the casting mold (14). The injectors (24) are in fluid communication with the mold cavity (16) through the bottom side (26) of the casting mold (14). A molten material holder furnace (12) is located beneath the casting mold (14). The holder furnace (12) defines molten material receiving chambers (36) configured to separately contain supplies of two different molten materials (37, 38). The holder furnace (12) is positioned such that the injectors (24) extend downward into the receiving chamber (36). The receiving chamber (36) is separated into at least two different flow circuits (51, 52). A first molten material (37) is received in a first flow circuit (51), and a second molten material (38) is received into a second flow circuit (52). The first and second molten materials (37, 38) are injected into the mold cavity (16) by the injectors (24) acting against the force of gravity. The injectors (24) are positioned such that the first and second molten materials (37, 38) are injected into different areas of the mold cavity (16). The molten materials (37, 38) are allowed to solidify and the resulting compound cast product is removed from the mold cavity (16).

Solubility of Hydrogen and Nitrogen in liquid cast iron during melting and mold filling

OpenAIRE

Diószegi, Attila; Elfsberg, Jessica; Diószegi, Zoltán

2016-01-01

Defect formation like gas- and shrinkage porosity at cast iron component production is related to the content of gaseous elements in the liquid metal. The present work investigate the solubility of hydrogen and nitrogen in liquid iron aimed for production of lamellar and compacted graphite cast iron. The used methods and instruments are a combination of commercial measuring devices and novel experimental assemblies for measuring solubility of hydrogen and nitrogen during melting and mold fill...

Microstructure, SDAS and Mechanical Properties of A356 alloy Castings Made in Sand and Granulated Blast Furnace Slag Moulds

Directory of Open Access Journals (Sweden)

Jinugu B. R.

2017-03-01

Full Text Available Investigations were carried out to ensure the granulated blast furnace (GBF slag as an alternative mould material in foundry industry by assessing the cast products structure property correlations. Sodium silicate-CO2 process was adopted for preparing the moulds. Three types of moulds were made with slag, silica sand individually and combination of these two with 10% sodium silicate and 20 seconds CO2 gassing time. A356 alloy castings were performed on these newly developed slag moulds. The cast products were investigated for its metallography and mechanical properties. Results reveal that cast products with good surface finish and without any defects were produced. Faster heat transfers in slag moulds enabled the cast products with fine and refined grain structured; and also, lower Secondary Dendrite Arm Spacing (SDAS values were observed than sand mould. Slag mould casting shows improved mechanical properties like hardness, compression, tensile and impact strength compared to sand mould castings. Two types of tensile fracture modes, namely cleavage pattern with flat surfaces representing Al−Si eutectic zone and the areas of broken Fe-rich intermetallic compounds which appear as flower-like morphology was observed in sand mould castings. In contrast, GBF slag mould castings exhibit majority in dimple fracture morphology with traces of cleavage fracture. Charpy impact fractured surfaces of sand mould castings shows both transgranular and intergranular fracture modes. Only intergranular fracture mode was noticed in both GBF slag and mixed mould castings.

The Lot Sizing and Scheduling of Sand Casting Operations

NARCIS (Netherlands)

Hans, Elias W.; van de Velde, S.L.; van de Velde, Steef

2011-01-01

We describe a real world case study that involves the monthly planning and scheduling of the sand-casting department in a metal foundry. The problem can be characterised as a single-level multi-item capacitated lot-sizing model with a variety of additional process-specific constraints. The main

Development of automated system based on neural network algorithm for detecting defects on molds installed on casting machines

Science.gov (United States)

Bazhin, V. Yu; Danilov, I. V.; Petrov, P. A.

2018-05-01

During the casting of light alloys and ligatures based on aluminum and magnesium, problems of the qualitative distribution of the metal and its crystallization in the mold arise. To monitor the defects of molds on the casting conveyor, a camera with a resolution of 780 x 580 pixels and a shooting rate of 75 frames per second was selected. Images of molds from casting machines were used as input data for neural network algorithm. On the preparation of a digital database and its analytical evaluation stage, the architecture of the convolutional neural network was chosen for the algorithm. The information flow from the local controller is transferred to the OPC server and then to the SCADA system of foundry. After the training, accuracy of neural network defect recognition was about 95.1% on a validation split. After the training, weight coefficients of the neural network were used on testing split and algorithm had identical accuracy with validation images. The proposed technical solutions make it possible to increase the efficiency of the automated process control system in the foundry by expanding the digital database.

Effect of moulding sand on statistically controlled hybrid rapid casting solution for zinc alloys

Energy Technology Data Exchange (ETDEWEB)

Singh, Rupinder [Guru Nanak Dev Engineering College, Ludhiana (India)

2010-08-15

The purpose of the present investigations is to study the effect of moulding sand on decreasing shell wall thickness of mould cavities for economical and statistically controlled hybrid rapid casting solutions (combination of three dimensional printing and conventional sand casting) for zinc alloys. Starting from the identification of component/ benchmark, technological prototypes were produced at different shell wall thicknesses supported by three different types of sands (namely: dry, green and molasses). Prototypes prepared by the proposed process are for assembly check purpose and not for functional validation of the parts. The study suggested that a shell wall with a less than recommended thickness (12mm) is more suitable for dimensional accuracy. The best dimensional accuracy was obtained at 3mm shell wall thickness with green sand. The process was found to be under statistical control

ASSESSMENT OF SURFACE FINISH AND DIMENSIONAL ACCURACY OF TOOLS MANUFACTURED BY METAL CASTING IN RAPID PROTOTYPING SAND MOULDS

Directory of Open Access Journals (Sweden)

Nyembwe, K.

2012-11-01

Full Text Available In this paper, an initial assessment of the quality parameters of the surface finish and dimensional accuracy of tools made by metal casting in rapid prototyping (RP sand moulds is undertaken. A case study from a local tool room, dealing with the manufacturing of an aluminium die for the lost wax process, is employed. Modern techniques, including surface roughness analysis and three dimensional scanning, are used to determine and understand how each manufacturing step influences the final quality of the cast tool. The best surface finish obtained for the cast die had arithmetic average roughness (Ra and mean average roughness (Rz respectively equal to 3.23m and 11.38m. In terms of dimensional accuracy, 82% of cast-die points coincided with the Computer Aided Design (CAD data, which is within the typical tolerances of sand cast products. The investigation shows that mould coating contributes slightly to the improvement of the cast tool surface finish. The study also found that the additive manufacturing of the sand mould was the chief factor responsible for the loss of dimensional accuracy. These findings indicate that machining will always be required to improve the surface finish and the dimensional accuracy of cast tools in RP sand moulds.

A coupled model on fluid flow, heat transfer and solidification in continuous casting mold

Directory of Open Access Journals (Sweden)

Xu-bin Zhang

2017-11-01

Full Text Available Fluid flow, heat transfer and solidification of steel in the mold are so complex but crucial, determining the surface quality of the continuous casting slab. In the current study, a 2D numerical model was established by Fluent software to simulate the fluid flow, heat transfer and solidification of the steel in the mold. The VOF model and k-ε model were applied to simulate the flow field of the three phases (steel, slag and air, and solidification model was used to simulate the solidification process. The phenomena at the meniscus were also explored through interfacial tension between the liquid steel and slag as well as the mold oscillation. The model included a 20 mm thick mold to clarify the heat transfer and the temperature distribution of the mold. The simulation results show that the liquid steel flows as upper backflow and lower backflow in the mold, and that a small circulation forms at the meniscus. The liquid slag flows away from the corner at the meniscus or infiltrates into the gap between the mold and the shell with the mold oscillating at the negative strip stage or at the positive strip stage. The simulated pitch and the depth of oscillation marks approximate to the theoretical pitch and measured depth on the slab.

Casting of Hearth Plates from High-chromium Steel

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Drotlew A.

2014-12-01

Full Text Available The paper presents the results of studies on the development of manufacturing technologies to cast hearth plates operating in chamber furnaces for heat treatment. Castings made from the heat-resistant G-X40CrNiSi27-4 steel were poured in hand-made green sand molds. The following operations were performed: computer simulation to predict the distribution of internal defects in castings produced by the above mentioned technology with risers bare and coated with exothermic and insulating sleeves, analysis of each variant of the technology, and manufacture of experimental castings. As a result of the conducted studies and analysis it was found that the use of risers with exothermic sleeves does not affect to a significant degree the quality of the produced castings of hearth plates, but it significantly improves the metal yield.

Hot-Tearing Assessment of Multicomponent Nongrain-Refined Al-Cu Alloys for Permanent Mold Castings Based on Load Measurements in a Constrained Mold

Science.gov (United States)

Sabau, Adrian S.; Mirmiran, Seyed; Glaspie, Christopher; Li, Shimin; Apelian, Diran; Shyam, Amit; Allen Haynes, J.; Rodriguez, Andres F.

2018-06-01

The hot-tearing resistance of multicomponent Al-Cu alloys during permanent mold casting was investigated using a constrained permanent mold in which the load and temperature were measured. The nominal Cu composition was varied from 5 to 8 wt pct. Casting experiments were conducted without adding any grain-refining inoculants. The following variables, which were obtained from the measured load data during casting, were considered to assess the hot-tearing resistance of the Al-Cu multicomponent alloys: "V"-like signature in the load rate variation, load at solidus point, and load rate average over the freezing range. In addition, a hot-tearing criterion based on the variation of the fraction of solid in the late stages of solidification was used. It was found that all criteria considered can accurately predict the alloys with the lowest and highest hot-tear resistance, respectively. It was found that the rate of measured load during casting could be used to indicate substantial hot tearing. However, the load rate variation could not be used to detect when small hot tears were present. Among all the criteria considered, the load at the solidus point shows an excellent agreement with experimentally observed hot-tearing resistance for all but one alloy. The poorly resistant hot-tearing alloys exhibited mainly coarse columnar grains while the most hot-tearing resistant alloys exhibited a much more refined grain microstructure. This is the first study in which good hot-tear resistance is demonstrated for multicomponent Al-Cu alloys with nominal Cu content greater than 7 wt pct.

Reuse of waste foundry sand through interaction with sodium silicate binder

International Nuclear Information System (INIS)

Souza, J.C.; Chinelatto, A.S.A.; Chinelatto, A.L.; Oliveira, I.L.

2012-01-01

Green sand molds are used in metal casting process. However, after heating, activated bentonite present in green sand lose the binding properties, and part of the foundry sand has to be discarded from the process. The ABNT NBR 15.984/2011 establishes the management of waste foundry sand (WFS) avoiding disposal in landfills. The objective of this work was to investigate the possibility of reusing the WFS from the study of their interaction with sodium silicate binder. Studies with silica sand and new green sand was performed to compare the results obtained with the WFS. The characterizations of the samples were performed by measures the compressive strength, X-ray diffraction, optical microscopy and scanning electron microscopy. The results showed that there is interaction of the sodium silicate with the WFS as well as with the silica sand and green sand. (author)

Characterization of Coated Sand Cores from Two Different Binder Systems for Grey Iron Castings

DEFF Research Database (Denmark)

Nwaogu, Ugochukwu Chibuzoh; Tiedje, Niels Skat; Poulsen, Thomas

or veining and metal penetration defects. The use of refractory coatings on cores is fundamental to obtaining acceptable casting surface quality and is used on resin bonded cores in production foundries. In this study new sol gel-coated sand cores made from coldbox and furan binder systems were investigated......Expansion defects on the surface of the castings include sand burn-in, metal penetration and/or veining, finning or scab. Veining or finning and metal penetration are of interest. These defects are associated with silica sand and result from the penetration of liquid metal into cracks formed during...... differential expansion of the core during heating. The rapid expansion of silica sand up to 600 oC and especially at 573 oC, where the α – β phase transformation occurs, is the cause of stresses in the core system. These stresses cause crack formation and metal melt flows into these cracks causing finning...

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

Energy Technology Data Exchange (ETDEWEB)

Thangirala, Mani

2015-09-30

demonstrated the importance of proper heat treat cycles for Homogenization, and Solutionizing parameters selection and implementation. 3) Step blocks casting of Nimonic 263: Carried out casting solidification simulation analysis, NDT inspection methods evaluation, detailed test matrix for Chemical, Tensile, LCF, stress rupture, CVN impact, hardness and J1C Fracture toughness section sensitivity data and were reported. 4) Centrifugal Casting of Haynes 282, weighing 1400 lbs. with hybrid mold (half Graphite and half Chromite sand) mold assembly was cast using compressor casing production tooling. This test provided Mold cooling rates influence on centrifugally cast microstructure and mechanical properties. Graphite mold section out performs sand mold across all temperatures for 0.2% YS; %Elongation, %RA, UTS at 1400°F. Both Stress-LMP and conditional Fracture toughness plots data were in the scatter band of the wrought alloy. 5) Fundamental Studies on Cooling rates and SDAS test program. Evaluated the influence of 6 mold materials Silica, Chromite, Alumina, Silica with Indirect Chills, Zircon and Graphite on casting solidification cooling rates. Actual Casting cooling rates through Liquidus to Solidus phase transition were measured with 3 different locations based thermocouples placed in each mold. Compared with solidification simulation cooling rates and measurement of SDAS, microstructure features were reported. The test results provided engineered casting potential methods, applicable for heavy section Haynes 282 castings for optimal properties, with foundry process methods and tools. 6) Large casting of Haynes 282 Drawings and Engineering FEM models and supplemental requirements with applicable specifications were provided to suppliers for the steam turbine proto type feature valve casing casting. Molding, melting and casting pouring completed per approved Manufacturing Process Plan during 2014 Q4. The partial valve casing was successfully cast after casting methods were

Casting Technology.

Science.gov (United States)

Wright, Michael D.; And Others

1992-01-01

Three articles discuss (1) casting technology as it relates to industry, with comparisons of shell casting, shell molding, and die casting; (2) evaporative pattern casting for metals; and (3) high technological casting with silicone rubber. (JOW)

Energy-Saving Melting and Revert Reduction Technology (E-SMARRT): Lost Foam Thin Wall - Feasibility of Producing Lost Foam Castings in Aluminum and Magnesium Based Alloys

Energy Technology Data Exchange (ETDEWEB)

Fasoyinu, Yemi [CanmetMATERIALS; Griffin, John A. [University of Alabama - Birmingham

2014-03-31

With the increased emphasis on vehicle weight reduction, production of near-net shape components by lost foam casting will make significant inroad into the next-generation of engineering component designs. The lost foam casting process is a cost effective method for producing complex castings using an expandable polystyrene pattern and un-bonded sand. The use of un-bonded molding media in the lost foam process will impose less constraint on the solidifying casting, making hot tearing less prevalent. This is especially true in Al-Mg and Al-Cu alloy systems that are prone to hot tearing when poured in rigid molds partially due to their long freezing range. Some of the unique advantages of using the lost foam casting process are closer dimensional tolerance, higher casting yield, and the elimination of sand cores and binders. Most of the aluminum alloys poured using the lost foam process are based on the Al-Si system. Very limited research work has been performed with Al-Mg and Al-Cu type alloys. With the increased emphasis on vehicle weight reduction, and given the high-strength-to-weight-ratio of magnesium, significant weight savings can be achieved by casting thin-wall (≤ 3 mm) engineering components from both aluminum- and magnesium-base alloys.

Molding and casting process of a depleted uranium shield for a multipurpose type B (U) transport package of radioactive substances

International Nuclear Information System (INIS)

Raffaeli, Hector A.; Acosta, Mario; Ilarri, Sergio; Alonso, Paula R.; Gargano, Pablo H.; Rubiolo, Gerardo H.

2009-01-01

Anticipating future demand for transport of radioisotopes, a high performance transport package (BU-MAN) with a gamma barrier built in depleted uranium (DU) has been designed by the Radioisotope and Radiation Program (P4) of CNEA in 2003. The shield is a hollow cylinder of approximately 173 mm outside diameter, 223 mm in height, a cylindrical hollow interior 63 mm diameter and 166 mm in height, and a cylindrical plug 58 mm diameter and 57 mm height. Its total weight is 84 Kg. In the period 2004-2006 the Special Alloys Group (DM-GIDAT-GAEN-CNEA) has conducted several developments in order to obtain the mentioned shield, including a manufacturing test casting SAE 1010 in a sand mold. The confirmation of its properties, mechanical and gamma shield are being evaluated by licensing tests of the whole package. In this paper we show all metallurgical processes involved to get the shield in metallic DU. (author)

Mathematics simulation and experiments of continuous casting with strip feeding in mold

Directory of Open Access Journals (Sweden)

M. G. Shen

2017-01-01

Full Text Available Steel strip feeding technology can reduce the degree of superheat of the molten steel, change the solidification order of the molten steel; raise the equiaxed crystal rate of the slab and improve the continuous casting quality. The paper establishes the mathematical model of heat transfer and temperature field of casting billet of steel strip feeding in continuous casting mold. Results show that if Plate Billet is 1 000 mm × 220 mm and the steel strip is 100 mm × 3 mm, feeding position of parallel is 250 mm from the narrow side. When the feeding speed is 3,6 m/min, the superheat degree can be reduced by 5 °C, and the solidification length can be reduced by 2,9 m. When the feeding speed is 6 m/min, the superheat degree can be reduced by about 9 °C, and the solidification length can be reduced by 3,7 m. The results of the test in a steel plant are in good agreement with the experimental results.

Casting Characteristics of High Cerium Content Aluminum Alloys

Energy Technology Data Exchange (ETDEWEB)

Weiss, D; Rios, O R; Sims, Z C; McCall, S K; Ott, R T

2017-09-05

This paper compares the castability of the near eutectic aluminum-cerium alloy system to the aluminum-silicon and aluminum-copper systems. The alloys are compared based on die filling capability, feeding characteristics and tendency to hot tear in both sand cast and permanent mold applications. The castability ranking of the binary Al–Ce systems is as good as the aluminum-silicon system with some deterioration as additional alloying elements are added. In alloy systems that use cerium in combination with common aluminum alloying elements such as silicon, magnesium and/or copper, the casting characteristics are generally better than the aluminum-copper system. In general, production systems for melting, de-gassing and other processing of aluminum-silicon or aluminum-copper alloys can be used without modification for conventional casting of aluminum-cerium alloys.

New sol–gel refractory coatings on chemically-bonded sand cores for foundry applications to improve casting surface quality

DEFF Research Database (Denmark)

Nwaogu, Ugochukwu Chibuzoh; Poulsen, T.; Stage, R.K.

2011-01-01

Foundry refractory coatings protect bonded sand cores and moulds from producing defective castings during the casting process by providing a barrier between the core and the liquid metal. In this study, new sol–gel refractory coating on phenolic urethane cold box (PUCB) core was examined. The coa......Foundry refractory coatings protect bonded sand cores and moulds from producing defective castings during the casting process by providing a barrier between the core and the liquid metal. In this study, new sol–gel refractory coating on phenolic urethane cold box (PUCB) core was examined......–gel coated cores have better surface quality than those from uncoated cores and comparable surface quality with the commercial coatings. Therefore, the new sol–gel coating has a potential application in the foundry industry for improving the surface finish of castings thereby reducing the cost of fettling...

Characterization of fold defects in AZ91D and AE42 magnesium alloy permanent mold castings

International Nuclear Information System (INIS)

Bichler, L.; Ravindran, C.

2010-01-01

Casting premium-quality magnesium alloy components for aerospace and automotive applications poses unique challenges. Magnesium alloys are known to freeze rapidly prior to filling a casting cavity, resulting in misruns and cold shuts. In addition, melt oxidation, solute segregation and turbulent metal flow during casting contribute to the formation of fold defects. In this research, formation of fold defects in AZ91D and AE42 magnesium alloys cast via the permanent mold casting process was investigated. Computer simulations of the casting process predicted the development of a turbulent metal flow in a critical casting region with abrupt geometrical transitions. SEM and light optical microscopy examinations revealed the presence of folds in this region for both alloys. However, each alloy exhibited a unique mechanism responsible for fold formation. In the AZ91D alloy, melt oxidation and velocity gradients in the critical casting region prevented fusion of merging metal front streams. In the AE42 alloy, limited solubility of rare-earth intermetallic compounds in the α-Mg phase resulted in segregation of Al 2 RE particles at the leading edge of a metal front and created microstructural inhomogeneity across the fold.

Effects of microstructures on low cycle fatigue behavior in Al-Si-Mg cast alloys

International Nuclear Information System (INIS)

Han, Sang Won; Kim, Sug Won

2002-01-01

Low cycle fatigue tests were carried out using four kinds of Al-7%Si-0.4Mg cast alloys, i.e., two kinds of sand mold casts, permanent mold cast and semi-solid die cast. They were heat-treated in the condition of under aging and over aging to investigate effects of precipitates on fatigue. All tests were conducted under axial plastic strain amplitude control. Stress level of cyclic hardening curves increased sensitively with needle like eutectic Si particle, refine grain size and dendrite arm spacing (DAS). In particular, the refined grain structure of under aged matrix was more effective encourager for cyclic hardening compared with DAS and eutectic Si particle size. After rapid increase in cyclic hardening during several number of cycles, the stress amplitude kept increasing steadily until fracture in under aged alloys strengthened by shearable G.P. zone. On the other hand, over aged alloys strengthened by non-shearable β ' precipitates generated more drastic initial hardening and the stress amplitude reached the saturation state in quite early stage of the fatigue

The influence of mold temperature on the fit of cast crowns with commercially pure titanium Influência de temperaturas do molde na adaptação de coroas fundidas em titânio comercialmente puro

Directory of Open Access Journals (Sweden)

Wagner Sotero Fragoso

2005-06-01

Full Text Available Commercially pure titanium (CP Ti has been widely applied to fabricate cast devices because of its favorable properties. However, the mold temperature recommended for the manufacture of casts has been considered relatively low, causing inadequate castability and poor marginal fit of cast crowns. This study evaluated and compared the influence of mold temperature (430°C - as control, 550°C, 670°C on the marginal discrepancies of cast CP Ti crowns. Eight bovine teeth were prepared on a mechanical grinding device and impressions were used to duplicate each tooth and produce eight master dies. Twenty-four crowns were fabricated using CP Ti in three different groups of mold temperature (n = 8: 430°C (as control, 550°C and 670°C. The gap between the crown and the bovine tooth was measured at 50 X magnification with a traveling microscope. The marginal fit values of the cast CP Ti crowns were submitted to the Kruskal-Wallis test (p = 0.03. The 550°C group (95.0 µm showed significantly better marginal fit than the crowns of the 430°C group (203.4 µm and 670°C group (213.8 µm. Better marginal fit for cast CP Ti crowns was observed with the mold temperature of 550°C, differing from the 430°C recommended by the manufacturer.O titânio comercialmente puro (Ti c.p. tem sido largamente empregado na elaboração de estruturas protéticas fundidas devido às suas propriedades favoráveis. Entretanto, a temperatura do molde recomendada pelo fabricante tem sido considerada baixa, causando inadequada fundibilidade e precária adaptação marginal de coroas fundidas. Este estudo avaliou e comparou a influência de temperaturas do molde (430°C - como controle, 550°C, 670°C na discrepância marginal de coroas fundidas em Ti c.p. Oito dentes bovinos foram preparados em um torno mecânico e moldados para produzirem oito modelos-mestre. Vinte e quatro coroas foram confeccionadas em Ti c.p. para três grupos de temperatura do molde (n = 8: 430°C (como

Method for casting thin metal objects

Science.gov (United States)

Pehrson, Brandon P; Moore, Alan F

2015-04-14

Provided herein are various embodiments of systems for casting thin metal plates and sheets. Typical embodiments include layers of mold cavities that are oriented vertically for casting the metal plates. In some embodiments, the mold cavities include a beveled edge such that the plates that are cast have a beveled edge. In some embodiments, the mold cavities are filled with a molten metal through an open horizontal edge of the cavity. In some embodiments, the mold cavities are filled through one or more vertical feed orifices. Further disclosed are methods for forming a thin cast metal plate or sheet where the thickness of the cast part is in a range from 0.005 inches to 0.2 inches, and the surface area of the cast part is in a range from 16 square inches to 144 square inches.

[Research on investing methods and mold cooling methods of the self-made investment for pure titanium castings].

Science.gov (United States)

Zhao, Juan; Huang, Xu; Zhao, Yun-Feng; Xiao, Mao-Chun; Li, Yong

2006-10-01

To observe the influence of different investing methods and mold cooling methods on pure titanium castings invested in the self-made investment, and to provide theoretic base for the development for the investment. The influence of investing methods (one-step investing method and two-step investing method) on castability and crown fit of titanium castings were investigated, and the influence of cooling methods on reaction layers, mechanical properties and crown fit of titanium castings were investigated. Both the investing methods exhibited good castability, but only the titanium full crowns by one-step investing method showed clinically acceptable fit. Although the quenching group showed thinner reaction layer(100 microm), lower strength and similar elongation rate, the titanium castings by bench cooling showed clinically acceptable full crown fit with 115 microm thick reaction layer as cast. The one-step investing method and the bench cooling are recommended for the self-made investment.

Aplikasi Cetakan Permanen untuk Meningkatkan Produksi dan Kualitas Produk IKM Pengecoran Logam Kuningan di Ngawen, Sidokarto, Godean, Yogyakarta

Directory of Open Access Journals (Sweden)

Suyitno Suyitno

2016-12-01

Full Text Available Small and Medium Enterprises (SME brass foundry in Ngawen Sidokarto, District of Godean, Sleman, Yogyakarta mostly produced cow necklace accessories (klonthong and jathilan accessories (klinthing. Te industry and business management are arranged within the scope of family. Te products are relatively low in quality and its market share is limited and tend to be traditional. Tis condition is caused by the weak knowledge of the management and the method of casting metals and metal science. Brass casting methode, that was used at IKM partner, is casting with mold of sand or soil. Tis process requires the making process of sand molds, that is removed afer the brass solidify. For large quantities products, this process is inefcient and takes a long time. It would require a more efcient and faster method in the production process. Method of sand casting and ceramics have been used by SMEs cast brass in Yogyakarta, however it  has many disadvantages in terms of increased productivity and quality as well as the expansion of product applications. Te permanent mold casting of iron is a casting method which has many advantages over other methods, but the use for SMEs has not been applied in the SME of cast brass. Te permanen mold casting methods was introduced to SME partners. Tis replaces the sand mold materials and molding sand. It is expected the casting process is faster because the mold can be used for a large number of products. Te results show that the application of the technology results in products with precision and consistent in shape and size. Community Service of UGM with Appropriate Technology has also collaborated with  Industry and Trade service of Yogyakarta donation of production machinery for making permanent mold. It can be concluded that the application of permanen mold in the brass foundry industry improve the product precision and the speed of produsction.

Simulation of Distortion and Residual Stress Development During Heat Treatment of Steel Castings

Energy Technology Data Exchange (ETDEWEB)

Beckermann, Christoph; Carlson, Kent

2011-07-22

of the Navy-C ring (a classical test shape for heat treatment experiments) for several carbon and low alloy steels in order to generate data necessary to validate the code. The predicted distortions were in reasonable agreement with the experimentally measured values. However, the final distortions in the castings were small, making it difficult to determine how accurate the predictions truly are. It is recommended that further validation of the software be performed with the aid of additional experiments with large production steel castings that experience significant heat treatment distortions. It is apparent from this research that the mechanical properties of the bonded sand used for cores and sand molds are key in producing accurate stress simulation results. Because of this, experiments were performed to determine the temperature-dependent elastic modulus of a resin-bonded sand commonly utilized in the steel casting industry. The elastic modulus was seen to vary significantly with heating and cooling rates. Also, the retained room temperature elastic modulus after heating was seen to degrade significantly when the sand was heated above 125°C. The elastic modulus curves developed in this work can readily be utilized in casting simulation software. Additional experiments with higher heating rates are recommended to determine the behavior of the elastic modulus in the sand close to the mold-metal interface. The commercial heat treatment residual stress and distortion code, once fully validated, is expected to result in an estimated energy savings of 2.15 trillion BTU's/year. Along with these energy savings, reduction of scrap and improvement in casting yield will result in a reduction of the environmental emissions associated with the melting and pouring of the metal which will be saved as a result of this technology.

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.

Rheological Characterization of Green Sand Flow

DEFF Research Database (Denmark)

Jabbaribehnam, Mirmasoud; Spangenberg, Jon; Hovad, Emil

2016-01-01

The main aim of this paper is to characterize experimentally the flow behaviour of the green sand that is used for casting of sand moulds. After the sand casting process is performed, the sand moulds are used for metal castings. The rheological properties of the green sand is important to quantif...

Characteristics and infl uence factors of mold fi lling process in permanent mold with a slot gating system

Directory of Open Access Journals (Sweden)

Chen Changjun

2009-11-01

Full Text Available The main problems caused by improper gating are entrained aluminum oxide fi lms and entrapped gas. In this study, the slot gating system is employed to improve mold fi lling behavior and therefore, to improve the quality of aluminum castings produced in permanent molds. An equipment as well as operation procedures for real-time X-ray radiography of molten aluminum fl owing into permanent molds have been developed. Graphite molds transparent to X-rays are utilized which make it possible to observe the fl ow pattern through a number of vertically oriented gating systems. The investigation discovers that there are many infl uencing factors on the mold fi lling process. This paper focuses its research on some of the factors, such as the dimensions of the vertical riser and slot thickness, as well as roughness of the coating layer. The results indicate that molten metal can smoothly fi ll into casting cavity with a proper slot gating system. A bigger vertical riser, proper slot thickness and rougher coating can provide not only a better mold fi lling pattern, but also hot melt into the top of the cavity. A proper temperature gradient is obtainable, higher at the bottom and lower at the top of the casting cavity, which is in favor of feeding during casting solidifi cation.

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

Experimental Observation and Analytical Modeling of Melting and Solidification during Aluminum Alloy Repair by Turbulence Flow Casting

Directory of Open Access Journals (Sweden)

Muki Satya Permana

2015-10-01

Full Text Available This paper presents an overview on the state of the art of applicable casting technology for applications in the field of repairing aluminum alloy components. Repair process on the Al alloy sample using similar metal has been carried out to investigate the micro-structural effect. Joining occurs as a result of convection heat transfer of molten flow into the sand mold which melts the existing base metal inside the mold and subsequent solidification. The analytical model has been developed to describe aluminum alloy component repair by turbulence flow casting. The model is designed based on heat transfer principle that can handle the phenomena of heat flow. The experimental result and analytical model analyses pointed out that joint quality are greatly affected by parameters of preheating temperature and duration of molten metal flow in the mold. To obtain a desired metallurgical sound at the joint, the optimum temperature and time were adjusted in order to obtain a similarity of microstructure between filler and base metal. This model is aimed to predict the use of the process parameter ranges in order to have the optimum parameters when it is applied to the experiment. The fixed parameters are flow rate, sand ratio, and pouring temperature. The process parameters are preheating temperature and pouring time. It is concluded that analytical modeling has good agreement with the experimental result.

Experimental Observation and Analytical Modeling of Melting and Solidification during Aluminum Alloy Repair by Turbulence Flow Casting

Directory of Open Access Journals (Sweden)

Muki Satya Permana

2017-03-01

Full Text Available This paper presents an overview on the state of the art of applicable casting technology for applications in the field of repairing Aluminium Alloy components. Repair process on the Aluminium sample using similar metal has been carried out to investigate the micro-structural effect. Joining occurs as a result of convection heat transfer of molten flow into the sand mold which melts the existing base metal inside the mold and subsequent solidification. The analytical model has been developed to describe aluminium component repair by Turbulence Flow Casting. The model built is based on heat transfer principle that can handle the phenomena of heat flow. The experimental result and analytical model analyses pointed out that joint quality are greatly affected by parameters of preheating temperature and duration of molten metal flow in the mold. To obtain a desired metallurgical sound at the joint, the optimum temperature and time were adjusted in order to obtain a similarity of microstructure between filler and base metal. This model is aimed to predict the use of the process parameter ranges in order to have the optimum parameters when it is applied to the experiment. The fixed parameters are flow rate, sand ratio, and pouring temperature. The process parameters are preheating temperature and pouring time. It is concluded that anaytical modeling has good agreement with the experimental result

Production of Steel Casts in Two-Layer Moulds with Alkaline Binders Part 1. Backing sand with the alkaline inorganic binder RUDAL

Directory of Open Access Journals (Sweden)

M. Holtzer

2011-04-01

Full Text Available Steel casts in Z.N. POMET were produced in moulds made of the moulding sand Floster. This sand did not have good knocking outproperties, required a significant binder addition (4.5-5.0 parts by weight, and the casting surface quality gave rise to clients objections.Therefore a decision of implementing two-layer moulds, in which the facing sand would consist of the moulding sand with an alkalineorganic binder while the backing sand would be made of the moulding sand with an inorganic binder also of an alkaline character - wasundertaken. The fraction of this last binder in the moulding sand mass would be smaller than that of the binder used up to now (waterglass. The application of two moulding sands of the same chemical character (highly alkaline should facilitate the reclamation processand improve the obtained reclaimed material quality, due to which it would be possible to increase the reclaim fraction in the mouldingsand (up to now it was 50%. The results of the laboratory investigations of sands with the RUDAL binder are presented in the paper.

Effects of different casting mould cooling rates on microstructure and properties of sand-cast Al-7.5Si-4Cu alloy

Directory of Open Access Journals (Sweden)

Liu Guanglei

2013-11-01

Full Text Available In this work, Al-7.5Si-4Cu alloy melt modified by Al-10Sr, RE and Al-5Ti-B master alloys was poured into multi-step moulds made from three moulding sands, including quartz, alumina and chromite, to investigate comparatively the effects of different cooling rates of the casting mould on the alloy's microstructures and mechanical properties. The results show that with an increase in wall thickness, the cooling rate decreases, the dendrite arm spacing (DAS increases significantly and the mechanical properties decrease steadily. The elongation is more sensitive to the cooling rate than the tensile strength. No obvious trend of the effect of wall thickness on hardness of the alloy was found. When the cooling rate is at its greatest, the microstructures and mechanical properties are the best when using chromite sand. The improvement of the properties is mainly attributed to the decrease of the DAS, the grain refinement and the metamorphic effect. Each of the three has a strong impact on the microstructures. Furthermore, a series of fitting models was established based on the data of the DAS to predict the mechanical properties of the multivariate sand-cast Al-7.5Si-4Cu alloy.

Measurement and simulation of deformation and stresses in steel casting

Science.gov (United States)

Galles, D.; Monroe, C. A.; Beckermann, C.

2012-07-01

Experiments are conducted to measure displacements and forces during casting of a steel bar in a sand mold. In some experiments the bar is allowed to contract freely, while in others the bar is manually strained using embedded rods connected to a frame. Solidification and cooling of the experimental castings are simulated using a commercial code, and good agreement between measured and predicted temperatures is obtained. The deformations and stresses in the experiments are simulated using an elasto-viscoplastic finite-element model. The high temperature mechanical properties are estimated from data available in the literature. The mush is modeled using porous metal plasticity theory, where the coherency and coalescence solid fraction are taken into account. Good agreement is obtained between measured and predicted displacements and forces. The results shed considerable light on the modeling of stresses in steel casting and help in developing more accurate models for predicting hot tears and casting distortions.

Measurement and simulation of deformation and stresses in steel casting

International Nuclear Information System (INIS)

Galles, D; Beckermann, C; Monroe, C A

2012-01-01

Experiments are conducted to measure displacements and forces during casting of a steel bar in a sand mold. In some experiments the bar is allowed to contract freely, while in others the bar is manually strained using embedded rods connected to a frame. Solidification and cooling of the experimental castings are simulated using a commercial code, and good agreement between measured and predicted temperatures is obtained. The deformations and stresses in the experiments are simulated using an elasto-viscoplastic finite-element model. The high temperature mechanical properties are estimated from data available in the literature. The mush is modeled using porous metal plasticity theory, where the coherency and coalescence solid fraction are taken into account. Good agreement is obtained between measured and predicted displacements and forces. The results shed considerable light on the modeling of stresses in steel casting and help in developing more accurate models for predicting hot tears and casting distortions.

Nonaqueous slip casting of high temperature ceramic superconductors using an investment casting technique

Science.gov (United States)

Hooker, Matthew W. (Inventor); Taylor, Theodore D. (Inventor); Wise, Stephanie A. (Inventor); Buckley, John D. (Inventor); Vasquez, Peter (Inventor); Buck, Gregory M. (Inventor); Hicks, Lana P. (Inventor)

1993-01-01

A process for slip casting ceramic articles that does not employ parting agents and affords the casting of complete, detailed, precision articles that do not possess parting lines is presented. This process is especially useful for high temperature superconductors and water-sensitive ceramics. A wax pattern for a shell mold is provided, and an aqueous mixture of a calcium sulfate-bonded investment material is applied as a coating to the wax pattern. The coated wax pattern is then dried, followed by curing to vaporize the wax pattern and leave a shell mold of the calcium sulfate-bonded investment material. The shell mold is cooled to room temperature, and a ceramic slip, created by dispersing a ceramic powder in an organic liquid, is poured therein. After a ceramic shell of desired thickness or a solid article has set up in the shell mold, excess ceramic slip is poured out. The shell mold is misted with water and peeled away from the ceramic article, after which the ceramic is fired to provide a complete, detailed, precision, high temperature superconductive ceramic article without parting lines. The casting technique may take place in the presence of a magnetic field to orient the ceramic powders during the casting process.

Clean Metal Casting; FINAL

International Nuclear Information System (INIS)

Makhlouf M. Makhlouf; Diran Apelian

2002-01-01

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

Mechanical and toxicological evaluation of concrete artifacts containing waste foundry sand.

Science.gov (United States)

Mastella, Miguel Angelo; Gislon, Edivelton Soratto; Pelisser, Fernando; Ricken, Cláudio; da Silva, Luciano; Angioletto, Elídio; Montedo, Oscar Rubem Klegues

2014-08-01

The creation of metal parts via casting uses molds that are generally made from sand and phenolic resin. The waste generated after the casting process is called waste foundry sand (WFS). Depending on the mold composition and the casting process, WFS can contain substances that prevent its direct emission to the environment. In Brazil, this waste is classified according to the Standard ABNT NBR 10004:2004 as a waste Class II (Non-Inert). The recycling of this waste is limited because its characteristics change significantly after use. Although the use (or reuse) of this byproduct in civil construction is a technically feasible alternative, its effects must be evaluated, especially from mechanical and environmental points of view. Thus, the objective of this study is to investigate the effect of the use of WFS in the manufacture of cement artifacts, such as masonry blocks for walls, structural masonry blocks, and paving blocks. Blocks containing different concentrations of WFS (up to 75% by weight) were produced and evaluated using compressive strength tests (35 MPa at 28 days) and toxicity tests on Daphnia magna, Allium cepa (onion root), and Eisenia foetida (earthworm). The results showed that there was not a considerable reduction in the compressive strength, with values of 35 ± 2 MPa at 28 days. The toxicity study with the material obtained from leaching did not significantly interfere with the development of D. magna and E. foetida, but the growth of the A. cepa species was reduced. The study showed that the use of this waste in the production of concrete blocks is feasible from both mechanical and environmental points of view. Copyright © 2014 Elsevier Ltd. All rights reserved.

Fan Fuel Casting Final Report

Energy Technology Data Exchange (ETDEWEB)

Imhoff, Seth D. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2017-09-28

LANL was approached to provide material and design guidance for a fan-shaped fuel element. A total of at least three castings were planned. The first casting is a simple billet mold to be made from high carbon DU-10Mo charge material. The second and third castings are for optimization of the actual fuel plate mold. The experimental scope for optimization is only broad enough for a second iteration of the mold design. It is important to note that partway through FY17, this project was cancelled by the sponsor. This report is being written in order to capture the knowledge gained should this project resume at a later date.

Modeling of solidification of MMC composites during gravity casting process

Directory of Open Access Journals (Sweden)

R. Zagórski

2013-04-01

Full Text Available The paper deals with computer simulation of gravity casting of the metal matrix composites reinforced with ceramics (MMC into sand mold. The subject of our interest is aluminum matrix composite (AlMMC reinforced with ceramic particles i.e. silicon carbide SiC and glass carbon Cg. The created model describes the process taking into account solidification and its influence on the distribution of reinforcement particles. The computer calculation has been carried out in 2D system with the use of Navier-Stokes equations using ANSYS FLUENT 13. The Volume of Fluid approach (VOF and enthalpy method have been used to model the air-fluid free surface (and also volume fraction of particular continuous phases and the solidification of the cast, respectively.

Numerical and Physical Parametric Analysis of a SEN with Flow Conditioners in Slab Continuous Casting Mold

Directory of Open Access Journals (Sweden)

Gonzalez-Trejo J.

2017-06-01

Full Text Available Some of the most recent technologies that improves the performance in continuous casting process has installed infrastructure outside the mold to modify the natural fluid flow pattern to obtain a quasi-steady condition and promote a uniform solidified shell of steel. The submerged entry nozzle distributes the liquid steel in the mold and can be used to obtain the flow symmetry condition with external geometry improvements. The fluid flow conditioners were located near the outlet ports of the nozzle. The aim of the modifiers is to impose a pseudo symmetric pattern in the upper zone of the mold by inhibiting the fluid exchange between the zones created by conditioners. This work evaluates the effect of the thickness and length of the fluid-flow modifiers on the overall performance of the submerged nozzle. These properties of the fluid-flow modifiers were normalized based on two of the geometric dimensions of the standard equipment. Numerical and physical simulations suggest that the flow modifier should be as thin as possible.

Dehydration of moulding sand in simulated casting process examined with neutron radiography

Energy Technology Data Exchange (ETDEWEB)

Schillinger, B., E-mail: Burkhard.Schillinger@frm2.tum.de [Technische Universitaet Muenchen, FRM II and Faculty for Physics E21, Lichtenbergstr. 1, 85748 Garching (Germany); Calzada, E. [Technische Universitaet Muenchen, FRM II and Faculty for Physics E21, Lichtenbergstr. 1, 85748 Garching (Germany); Eulenkamp, C.; Jordan, G.; Schmahl, W.W. [Ludwig-Maximilians-Universitaet Muenchen, Department fuer Geo- und Umweltwissenschaften, Sektion Kristallographie, Theresienstr. 41, 80333 Muenchen (Germany)

2011-09-21

Natural bentonites are an important material in the casting industry. Smectites as the main component of bentonites plasticize and stabilise sand moulds. Pore water as well as interlayer water within the smectites are lost as a function of time, location and temperature. Although rehydration of the smectites should be a reversible process, the industrially dehydrated smectites lose their capability to reabsorb water. This limits the number of possible process cycles of the mould material. A full understanding of the dehydration process would help to optimise the amount of fresh material to be added and thus save resources. A simulated metal casting was investigated with neutron radiography at the ANTARES neutron imaging facility of the FRM II reactor of Technische Universitaet Muenchen, Germany.

Production of an Amorphous Fe_<75>Si_<10>B_<15> Sheet by a Metallic Mold Casting Method and its Properties

OpenAIRE

Inoue, Akihisa; Yamamoto, Hirokazu; Saito, Takanobu; Masumoto, Tsuyosi

1993-01-01

The application of a metallic mold casting method to an Fe_Si_B_ alloy with the largest glass-forming ability in (Fe, Co, Ni)-Si-B system was found to cause the formation of a mostly single amorphous phase in a sheet form with a thickness of 0.1 mm. No distinct difference in thermal stability (crystallization temperature and heat of crystallization), hardness, Curie temperature and magnetization is detected between the as-cast sheet and the melt-spun amorphous ribbon with a thickness of 0.02 ...

Feeding and Distribution of Porosity in Cast Al-Si Alloys as Function of Alloy Composition and Modification

DEFF Research Database (Denmark)

Tiedje, Niels Skat; Taylor, John A.; Easton, Mark A.

2012-01-01

Unmodified, Na-modified, and Sr-modified castings of Al-7 pct Si and Al-12.5 pct Si alloys were cast in molds in which it was possible to create different cooling conditions. It is shown how solidification influences the distribution of porosity at the surface and the center of the castings...... of the casting, while Sr-modified castings solidify in a mushy manner that creates a more homogeneous distribution of porosity in the casting. The amount of porosity was highest in the Sr-modified alloys, lower in the Na-modified alloys, and lowest in the unmodified alloys. The size of the porosity-free layer...... as a function of modification and Si content in sand- and chill-cast samples. Eutectic modification, Si content, and cooling conditions have a great impact on the distribution of porosity. Unmodified and Na-modified castings are more easily fed with porosity tending to congregate near the centerline...

Premature melt solidification during mold filling and its influence on the as-cast structure

Science.gov (United States)

Wu, M.; Ahmadein, M.; Ludwig, A.

2018-03-01

Premature melt solidification is the solidification of a melt during mold filling. In this study, a numerical model is used to analyze the influence of the pouring process on the premature solidification. The numerical model considers three phases, namely, air, melt, and equiaxed crystals. The crystals are assumed to have originated from the heterogeneous nucleation in the undercooled melt resulting from the first contact of the melt with the cold mold during pouring. The transport of the crystals by the melt flow, in accordance with the socalled "big bang" theory, is considered. The crystals are assumed globular in morphology and capable of growing according to the local constitutional undercooling. These crystals can also be remelted by mixing with the superheated melt. As the modeling results, the evolutionary trends of the number density of the crystals and the volume fraction of the solid crystals in the melt during pouring are presented. The calculated number density of the crystals and the volume fraction of the solid crystals in the melt at the end of pouring are used as the initial conditions for the subsequent solidification simulation of the evolution of the as-cast structure. A five-phase volume-average model for mixed columnar-equiaxed solidification is used for the solidification simulation. An improved agreement between the simulation and experimental results is achieved by considering the effect of premature melt solidification during mold filling. Finally, the influences of pouring parameters, namely, pouring temperature, initial mold temperature, and pouring rate, on the premature melt solidification are discussed.

Interface Structure and Elements Diffusion of As-Cast and Annealed Ductile Iron/Stainless Steel Bimetal Castings

Directory of Open Access Journals (Sweden)

M. Ramadan

2018-04-01

Full Text Available Bimetal casting is considered to a promising technique for the production of high performance function materials. Heat treatment process for bimetal castings became an essential tool for improving interface structure and metallurgical diffusion bond. Molten iron alloy with carbon equivalent of 4.40 is poured into sand mold cavities containing solid 304 stainless steel strips insert. Specimens are heated to 7200C in an electrical heating furnace and holded at 720 0C for 60min and 180min. For as-cast specimens, a good coherent interface structure of ductile cast iron/304 stainless bimetal with four layers interfacial microstructure are obtained. Low temperature annealing at 720oC has a significat effect on the interface layers structure, where, three layers of interface structure are obtained after 180min annealing time because of the complete dissolving of thin layer of ferrite and multi carbides (Layer 2. Low temperature annealing shows a significant effect on the diffusion of C and otherwise shows slightly effect on the diffusion of Cr and Ni. Plearlite phase of Layer 3 is trsformed to spheroidal shape instead of lamallar shape in as-cast bimetals by low tempeature annealing at 720oC. The percent of the performed spheroidal cementit increases by increasing anneaaling time. Hardness of interface layers is changed by low temperauture annealing due to the significant carbon deffussion.

[A surface reacted layer study of titanium-zirconium alloy after dental casting].

Science.gov (United States)

Zhang, Y; Guo, T; Li, Z; Li, C

2000-10-01

To investigate the influence of the mold temperature on the surface reacted layer of Ti-Zr alloy castings. Ti-Zr alloy was casted into a mold which was made of a zircon (ZrO2.SiO2) for inner coating and a phosphate-bonded material for outer investing with a casting machine (China) designed as vacuum, pressure and centrifuge. At three mold temperatures (room temperature, 300 degrees C, 600 degrees C) the Ti-Zr alloy was casted separately. The surface roughness of the castings was calculated by instrument of smooth finish (China). From the surface to the inner part the Knoop hardness and thickness in reacted layer of Ti-Zr alloy casting was measured. The structure of the surface reacted layer was analysed by SEM. Elemental analyses of the interfacial zone of the casting was made by element line scanning observation. The surface roughness of the castings was increased significantly with the mold temperature increasing. At a higher mold temperature the Knoop hardness of the reactive layer was increased. At the three mold temperature the outmost surface was very hard, and microhardness data decreased rapidly where they reached constant values. The thickness was about 85 microns for castings at room temperature and 300 degrees C, 105 microns for castings at 600 degrees C. From the SEM micrograph of the Ti-Zr alloy casting, the surface reacted layer could be divided into three different layers. The first layer was called non-structure layer, which thickness was about 10 microns for room temperature group, 20 microns for 300 degrees C and 25 microns for 600 degrees C. The second layer was characterized by coarse-grained acicular crystal, which thickness was about 50 microns for three mold temperatures. The third layer was Ti-Zr alloy. The element line scanning showed non-structure layer with higher level of element of O, Al, Si and Zr, The higher the mold temperature during casting, the deeper the Si permeating and in the second layer the element Si could also be found

Simulation of transient fluid flow in mold region during steel continuous casting

International Nuclear Information System (INIS)

Liu, R; Thomas, B G; Sengupta, J

2012-01-01

A system of models has been developed to study transient flow during continuous casting and applied to simulate an event of multiple stopper-rod movements. It includes four sub-models to incorporate different aspects in this transient event. A three-dimensional (3-D) porous-flow model of the nozzle wall calculates the rate argon gas flow into the liquid steel, and the initial mean bubble size is estimated. Transient CFD models simulate multiphase flow of steel and gas bubbles in the Submerged Entry Nozzle (SEN) and mold and have been validated with experimental data from both nail dipping and Sub-meniscus Velocity Control (SVC) measurements. To obtain the transient inlet boundary conditions for the simulation, two semi-empirical models, a stopper-rod-position based model and a metal-level-based model, predict the liquid steel flow rate through the SEN based on recorded plant data. Finally the model system was applied to study the effects of stopper rod movements on SEN/mold flow patterns. Meniscus level fluctuations were calculated using a simple pressure method and compared well with plant measurements. Insights were gained from the simulation results to explain the cause of meniscus level fluctuations and the formation of sliver defects during stopper rod movements.

Study on the Surface Microstructure of a Modified STD61 Steel Mold Used for the Die Casting Process

Energy Technology Data Exchange (ETDEWEB)

Yu, Ha-Young; Lee, Seung-Joon; Kang, Minwoo; Lee, Suk-Jin; Lee, Young-Kook [Yonsei University, Seoul (Korea, Republic of); Yang, Won Jon [Korea Institute of Materials Science, Changwon (Korea, Republic of); Jeong, Jae Suk; Kim, Byung-Hoon [Doosan Heavy Industries and Construction, Changwon (Korea, Republic of)

2016-09-15

The surface microstructure and crack formation of an aluminum die-casting mold were investigated. The mold was made of a modified STD61 steel, and was used for more than 165,000 cycles. The mold surface consisted of four layers; an oxidized layer, a decarburized layer, a network carbide layer and a tempered martensite matrix. The depth down to the hardest network carbide layer was ⁓200 μm. Inside the matrix, M{sub 3}C transition carbides were dissolved so that solute C joined pre-existing M{sub 2}3C{sub 6} and MC carbides to make them coarse. About 60% of thermal fatigue cracks had a depth less than 200 μm due to the hard network carbide layer, which obstructed the propagation of cracks. Cracks of over 200 μm were filled with oxide wedges of Al and Si which was which flown from the molten alloy as well as the Fe oxide.

Numerical Simulation of Steady State Conduction Heat Transfer During the Solidification of Aluminum Casting in Green Sand Mould

Directory of Open Access Journals (Sweden)

Victor ANJO

2012-08-01

Full Text Available The solidification of molten metal during the casting process involves heat transfer from the molten metal to the mould, then to the atmosphere. The mechanical properties and grain size of metals are determined by the heat transfer process during solidification. The aim of this study is to numerically stimulate the steady conduction heat transfer during the solidification of aluminum in green sand mould using finite difference analysis 2D. The properties of materials used are industrial AI 50/60 AFS green sand mould, pure aluminum and MATLAB 7.0.1. for the numerical simulation. The method includes; the finite difference analysis of the heat conduction equation in steady (Laplace’s and transient states and using MATLAB to numerically stimulate the thermal flow and cooling curve. The results obtained are: the steady state thermal flow in 2D and transient state cooling curve of casting. The results obtain were consider relevant in the control of the grain size and mechanical properties of the casting.

Centrifugal vacuum casting for fuel cladding tube blanks

International Nuclear Information System (INIS)

Zelenskii, V.F.; Neklyudov, I.M.; Chernyi, B.P.; Zeidlits, M.P.; Vanzha, A.F.; Rubashko, V.G.; Ryabchikov, L.N.; Smirnov, Y.K.; Bespalova, V.R.; Mashkarova, V.T.; Rybal'chenko, N.D.

1990-01-01

An advanced technique for making tube blanks with an acceptable level of nonmetallic inclusions is vacuum induction melting combined with centrifugal casting, as the latter gives a cylindrical casting having an axial hole, while the cast metal has elevated density and contains fewer nonmetallic inclusions than does the metal cast in a stationary mold. The reduction in the nonmetallic inclusions occurs because of increased rates of floating up in the rotating mold on account of the centrifugal force and the rejection to the inner surface. One can choose the parameters such as the pouring speed, rotational speed, mold cooling, and liquid-metal temperature and can introduce a deoxidizer to remove the nonmetallic inclusions or reduce the grain size of them and produce an appropriate cast structure and obtain a metal whose quality is the same as that on vacuum induction melting with secondary arc remelting. For these purposes, the authors have developed centrifugal-casting machines for use under vacuum or in inert gases with horizontal and vertical mold rotation axes

HFIR Fuel Casting Support

Energy Technology Data Exchange (ETDEWEB)

Imhoff, Seth D. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Gibbs, Paul Jacob [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Solis, Eunice Martinez [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2017-09-28

Process exploration for fuel production for the High Flux Isotope Reactor (HFIR) using cast LEU-10wt.%Mo as an initial processing step has just begun. This project represents the first trials concerned with casting design and quality. The studies carried out over the course of this year and information contained in this report address the initial mold development to be used as a starting point for future operations. In broad terms, the final billet design is that of a solid rolling blank with an irregular octagonal cross section. The work covered here is a comprehensive view of the initial attempts to produce a sound casting. This report covers the efforts to simulate, predict, cast, inspect, and revise the initial mold design.

Simulation of the injection casting of metallic fuels

International Nuclear Information System (INIS)

Nakagawa, Tomokazu; Ogata, Takanari; Tokiwai, Moriyasu.

1989-01-01

For the fabrication of metallic fuel pins, injection casting is a preferable process because the simplicity of the process is suitable for remote operation. In this process, the molten metal in the crucible is injected into evacuated molds (suspended above the crucible) by pressurizing the casting furnace. Argonne National Laboratory has already adopted this process in the Integral Fast Reactor program. To obtain fuel pins with good quality, the casting parameters, such as the molten metal temperature, the magnitude of the pressure applied, the pressurizing rate, the cooling time, etc., must be optimized. Otherwise, bad-quality castings (short castings, rough surfaces, shrinkage cavities, mold fracture) may result. Therefore, it is very important in designing the casting equipment and optimizing the operation conditions to be able to predict the fluid and thermal behavior of the castings. This paper describes methods to simulate the heat and mass transfer in the molds and molten metallic fuel during injection casting. The results obtained by simulation are compared with experimental ones. Also, appropriate casting conditions for the uranium-plutonium-zirconium alloy are discussed based on the simulated results

In-situ surface hardening of cast iron by surface layer metallurgy

International Nuclear Information System (INIS)

Fischer, Sebastian F.; Muschna, Stefan; Bührig-Polaczek, Andreas; Bünck, Matthias

2014-01-01

Abrasive wear is a serious problem in many cast iron castings used in industry. To minimize failure and repair of these components, different strategies exist to improve their surface microhardness thus enhancing their wear resistance. However, most of these methods lead to very brittle and/or expensive castings. In the current work a new method for surface hardening is presented which utilizes surface layer metallurgy to generate in-situ a boron-enriched white cast iron surface layer with a high microhardness on a gray cast iron casting. To do this, sand molds are coated with a ferroboron suspension and cast with a cast iron melt. After solidification, a 100–900 µm thick layer of boron-enriched ledeburite is formed on the surface of the casting which produces an increase in the average microhardness from 284 HV 0.1 ±52 HV 0.1 to 505 HV 0.1 ±87 HV 0.1 . Analyses of the samples' core reveal a typical cast iron microstructure which leads to the conclusion that the coating mainly affects the castings' surface. By varying the grain size of the ferroboron powder in the coatings, it is shown that a powder size ≤100 µm is most suitable to create a boron-enriched ledeburite surface layer possessing high hardness values

Effect of cast steel production metallurgy on the emergence of casting defects

Directory of Open Access Journals (Sweden)

L. Čamek

2016-10-01

Full Text Available The paper documents metallurgical possibilities of high alloy cast steel production in open induction medium frequency furnaces and an electric arc furnace in a gravity die casting foundry. The observation was focused on the emergence of gas defects in steel castings. The content of gases achieved during the metallurgical processes was evaluated for every unit of the production equipment and the casting ladle before casting into disposable sand moulds. The sand mould area was considered to be constant. The aim was to evaluate the current metallurgical possibilities of affecting the content of gases in high alloy cast steel in the current technical conditions of the foundry.

Molding of strength testing samples using modern PDCPD material for purpose of automotive industry

Science.gov (United States)

Grabowski, L.; Baier, A.; Sobek, M.

2017-08-01

The casting of metal materials is widely known but the molding of composite polymer materials is not well-known method still. The initial choice of method for producing composite bodies was the method of casting of PDCPD material. For purpose of performing casting of polymer composite material, a special mold was made. Firstly, the 3D printed, using PLA material, mold was used. After several attempts of casting PDCPD many problems were encountered. The second step was to use mold milled from a firm and dense isocyanate foam. After several attempts research shown that this solution is more resistant to high-temperature peak, but this material is too fragile to use it several times. This solution also prevents mold from using external heating, which can be necessary for performing correct molding process. The last process was to use the aluminum mold, which is dedicated to PDCPD polymer composite, because of low adhesiveness. This solution leads to perform correct PDCPD polymer composite material injection. After performing casting operation every PDCPD testing samples were tested. These results were compared together. The result of performed work was to archive correct properties of injection of composite material. Research and results were described in detail in this paper.

Formula of Moulding Sand, Bentonite and Portland Cement toImprove The Quality of Al-Si Cast Alloy

OpenAIRE

Andoko Andoko; Poppy Puspitasari; Avita Ayu Permanasari; Didin Zakaria Lubis

2017-01-01

A binder is any material used to strengthen the bonding of moulding sand grains. The primary function of the binder is to hold the moulding sand and other materialstogether to produce high-quality casts. In this study, there were four binder compositions being tested, i.e. 5% bentonite + 5% Portland cement, 4% bentonite + 6% Portland cement, 6% bentonite + 4% Portland cement, and 7% bentonite + 3% Portland cement. Each specimen was measured for its compressive strength, shear strength, tensil...

CASTING FURNACES

Science.gov (United States)

Ruppel, R.H.; Winters, C.E.

1961-01-01

A device is described for casting uranium which comprises a crucible, a rotatable table holding a plurality of molds, and a shell around both the crucible and the table. The bottom of the crucible has an eccentrically arranged pouring hole aligned with one of the molds at a time. The shell can be connected with a vacuum.

Casting materials

Science.gov (United States)

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.

Anti-carburizing Coating for Resin Sand Casting of Low Carbon Steel Based on Composite Silicate Powder Containing Zirconium

Directory of Open Access Journals (Sweden)

Zhan Chunyi

2018-01-01

Full Text Available This paper studied the structure and properties of anticarburizing coating based on composite silicate powder containing zirconium by X-ray diffraction analyzer, thermal expansion tester, digital microscope and other equipment. It is introduced that the application example of the coating in the resin-sand casting of ZG1Cr18Ni9Ti stainless steel impeller. The anti-carburizing effect of the coating on the surface layer of the cast is studied by using direct reading spectrometer and spectrum analyzer. The change of the micro-structure of the coating after casting and cooling is observed by scanning electron microscope. The analysis of anti-carburizing mechanism of the coating is presented. The results indicate that the coating possesses excellent suspension property, brush ability, permeability, levelling property and crackresistance. The coating exhibits high strength and low gas evolution. Most of the coating could be automatically stripped off flakily when the casting was shaken out. The casting possesses excellent surface finish and antimetal penetration effect. The carburizing layer thickness of the stainless steel impeller casting with respect to allowable upper limit of carbon content is about 1mm and maximum carburizing rate is 23.6%. The anticarburizing effect of casting surface is greatly improved than that of zircon powder coating whose maximum carburizing rate is 67.9% and the carburizing layer thickness with respect to allowable upper limit of carbon content is greater than 2mm. The composite silicate powder containing zirconium coating substantially reduces the zircon powder which is expensive and radioactive and mainly dependent on imports. The coating can be used instead of pure zircon powder coating to effectively prevent metal-penetration and carburizing of resin-sand-casting surface of low carbon steel, significantly improve the foundry production environment and reduce the production costs.

Fabricación de piezas de fundición con grafito esferoidal en molde metálico

Directory of Open Access Journals (Sweden)

Urrestarazu, A.

2013-10-01

Full Text Available The features and suitability of high requirements ductile iron castings production using metallic moulds have been studied in the present work. The structural and mechanical properties of the produced castings have been analysed and compared to the corresponding ones but fabricated using green sand moulds according to a conventional production process. The higher cooling rate in the metallic moulds is the main cause for the appearance of the detected structural changes in castings. The mechanical and microstructural properties obtained directly on castings are remarkable due to the higher nodule count among other factors. Finally, the benefits and inconveniences found in this kind of production methodology using metallic moulds are also discussed.En este trabajo se estudia el empleo de moldes metálicos o permanentes para la fabricación de piezas de fundición esferoidal con elevados requerimientos funcionales y se analizan sus propiedades, comparándolas con piezas obtenidas utilizando moldes de arena de sílice, de acuerdo con las metodologías más habituales para este tipo de procesos. La elevada velocidad de solidificación y el posterior enfriamiento rápido de la austenita formada en estado sólido se erigen como los principales factores diferenciadores que originan las modificaciones estructurales detectadas en las piezas. Las propiedades físicas, mecánicas y microestructurales obtenidas directamente sobre pieza son destacables debido, entre otros aspectos, al gran número de esferoides grafíticos obtenidos en las piezas. Se discuten también las ventajas e inconvenientes encontrados en esta metodología de producción que emplea moldes fabricados con una aleación metálica específica.

Energy Saving Melting and Revert Reduction Technology (Energy-SMARRT): Clean Steel Casting Production

Energy Technology Data Exchange (ETDEWEB)

Kuyucak, Selcuk [CanmetMATERIALS; Li, Delin [CanmetMATERIALS

2013-12-31

Inclusions in steel castings can cause rework, scrap, poor machining, and reduced casting performance, which can obviously result in excess energy consumption. Significant progress in understanding inclusion source, formation and control has been made. Inclusions can be defined as non-metallic materials such as refractory, sand, slag, or coatings, embedded in a metallic matrix. This research project has focused on the mold filling aspects to examine the effects of pouring methods and gating designs on the steel casting cleanliness through water modeling, computer modeling, and melting/casting experiments. Early in the research project, comprehensive studies of bottom-pouring water modeling and low-alloy steel casting experiments were completed. The extent of air entrainment in bottom-poured large castings was demonstrated by water modeling. Current gating systems are designed to prevent air aspiration. However, air entrainment is equally harmful and no prevention measures are in current practice. In this study, new basin designs included a basin dam, submerged nozzle, and nozzle extension. The entrained air and inclusions from the gating system were significantly reduced using the new basin method. Near the end of the project, there has been close collaboration with Wescast Industries Inc., a company manufacturing automotive exhaust components. Both computer modeling using Magma software and melting/casting experiments on thin wall turbo-housing stainless steel castings were completed in this short period of time. Six gating designs were created, including the current gating on the pattern, non-pressurized, partially pressurized, naturally pressurized, naturally pressurized without filter, and radial choke gating without filter, for Magma modeling. The melt filling velocity and temperature were determined from the modeling. Based on the simulation results, three gating designs were chosen for further melting and casting experiments on the same casting pattern using

Energy Saving Melting and Revert Reduction (E-SMARRT): Precision Casting of Steel

Energy Technology Data Exchange (ETDEWEB)

Dr. Von L. Richards

2011-09-30

This project addresses improvements in metal casting processes by reducing scrap and reducing the cost of production, due to scrap reduction from investment casting and yield improvement offered by lost foam casting as compared to no-bake or green sand molding. The objectives for the investment casting portion of the subtask are to improve knowledge of fracture toughness of mold shells and the sources of strength limiting flaws and to understand the effects of wax reclamation procedures on wax properties. Applying 'clean steel' approaches to pouring technology and cleanliness in investment casting of steel are anticipated to improve incoming materials inspection procedures as they affect the microstructure and toughness of the shell. This project focused on two areas of study in the production of steel castings to reduce scrap and save energy: (1) Reducing the amount of shell cracking in investment cast steel production; (2) Investigate the potential of lost foam steel casting The basic findings regarding investment casting shell cracking were: (1) In the case of post pouring cracking, this could be related to phase changes in silica upon cooling and could be delayed by pouring arrangement strategies that maintained the shell surface at temperature for longer time. Employing this delay resulted in less adherent oxidation of castings since the casting was cooler at the time o fair exposure. (2) A model for heat transfer through water saturated shell materials under steam pressure was developed. (3) Initial modeling result of autoclave de-waxing indicated the higher pressure and temperature in the autoclave would impose a steeper temperature gradient on the wax pattern, causing some melt flow prior to bulk expansion and decreasing the stress on the green shell. Basic findings regarding lost foam casting of steel at atmospheric pressure: (1) EPS foam generally decomposes by the collapse mode in steel casting. (2) There is an accumulation of carbon pick-up at

Casting AISI 316 steel by gel cast

International Nuclear Information System (INIS)

Ozols, A; Thern, G; Rozenberg, S; Barreiro, M; Marajofsky, A

2004-01-01

The feasibility of producing AISI 316 steel components from their powders and avoiding their compaction is analyzed. A casting technique is tested that is similar to gel casting, used for ceramic materials. In the initial stage, the process consists of the formulation of a concentrated barbotine of powdered metal in a solution of water soluble organic monomers, which is cast in a mold and polymerized in situ to form a raw piece in the shape of the cavity. The process can be performed under controlled conditions using barbotines with a high monomer content from the acrylimide family. Then, the molded piece is slowly heated until the polymer is eliminated, and it is sintered at temperatures of 1160 o C to 1300 o C under a dry hydrogen atmosphere, until the desired densities are attained. The density and micro structure of the materials obtained are compared with those for the materials compacted and synthesized by the conventional processes. The preliminary results show the feasibility of the process for the production of certain kinds of structural components (CW)

Numerical simulation of low pressure die-casting aluminum wheel

Directory of Open Access Journals (Sweden)

Mi Guofa

2009-02-01

Full Text Available The FDM numerical simulation software, ViewCast system, was employed to simulate the low pressure die casting (LPDC of an aluminum wheel. By analyzing the mold-fi lling and solidifi cation stage of the LPDC process, the distribution of liquid fraction, temperature field and solidification pattern of castings were studied. The potential shrinkage defects were predicted to be formed at the rim/spoke junctions, which is in consistence with the X-ray detection result. The distribution pattern of the defects has also been studied. A solution towards reducing such defects has been presented. The cooling capacity of the mold was improved by installing water pipes both in the side mold and the top mold. Analysis on the shrinkage defects under forced cooling mode proved that adding the cooling system in the mold is an effective method for reduction of shrinkage defects.

Metalcasting competitiveness research. Final report

Energy Technology Data Exchange (ETDEWEB)

Piwonka, T.S.

1994-08-01

This report comprises eleven separate reports: prediction of non- metallic particle distribution, electromagnetic separation of inclusions from molten Al alloy, clean steel castings, waste stream identification and treatment, elastic wave lithotripsy for removal of ceramic from investment castings, metal penetration in sand molds, mold-metal interface gas composition, improved Alloy 718, specifications for iron oxide additions to no-bake sands, criteria functions for defect prediction, and computer-aided cooling curve analysis.

CASTING APPARATUS

Science.gov (United States)

Gray, C.F.; Thompson, R.H.

1958-09-23

An apparatus is described for casting small quantities of uranlum. It consists of a crucible having a hole in the bottom with a mold positioned below. A vertical rcd passes through the hole in the crucible and has at its upper end a piercing head adapted to break the oxide skin encasing a molten uranium body. An air tight cylinder surrounds the crucible and mold, and is arranged to be evacuated.

Fabrication of a zirconia MEMS-based microthruster by gel casting on PDMS soft molds

International Nuclear Information System (INIS)

Cheah, K H; Khiew, P S; Chin, J K

2012-01-01

A zirconia microelectromechanical-system-based microthruster was fabricated through a newly developed fabrication route. Gel casting of homogenously dispersed zirconia suspension on polydimethylsiloxane soft mold was utilized to replicate the geometries of microthruster design onto a ceramic layer of about 1.2 mm thick. Lamination of the patterned ceramic layer to another flat ceramic layer and subsequent sintering produced the microthruster. Characterizations on the fabricated prototype showed good shape retention on the replicated geometries and good quality of lamination. Shrinkage of about 10–15% was noted after sintering. The current fabrication route is particularly promising for the development of high-performance micropropulsion systems which require their structural material to survive in an extreme environment which is corrosive, of high temperature and highly oxidative. (paper)

Metallic Fuel Casting Development and Parameter Optimization Simulations

International Nuclear Information System (INIS)

Fielding, Randall S.; Kennedy, J.R.; Crapps, J.; Unal, C.

2013-01-01

Conclusions: • Gravity casting is a feasible process for casting of metallic fuels: – May not be as robust as CGIC, more parameter dependent to find right “sweet spot” for high quality castings; – Fluid flow is very important and is affected by mold design, vent size, super heat, etc.; – Pressure differential assist was found to be detrimental. • Simulation found that vent location was important to allow adequate filling of mold; • Surface tension plays an important role in determining casting quality; • Casting and simulations high light the need for better characterized fluid physical and thermal properties; • Results from simulations will be incorporated in GACS design such as vent location and physical property characterization

Studies on the Castability of Pure Titanium (Part 3) Influence of casting pressure and sprue diameter on the titanium castability

OpenAIRE

YONEDA, TAKANORI; KUROIWA, AKIHIRO; IGARASHI, YOSHIMASA; OHNO, TAKAFUMI; SEKIGUCHI, YUUJI; INOUE, YOSHIHISA; MIGO, SHINYA

1998-01-01

We analyzed the external defects of castings with mesh grid patterns with 3 different kinds of phosphate bonded casting molds with 2 parameters (sprue diameter and casting pressure). Castability with pure titanium was affected by the parameters of sprue diameter, and casting pressure with different casting molds. The sprue condition was the most affective casting condition in the all directional pressure type casting machine. In 2 types of casting molds, one was strongly affected by the casti...

Fabrication of Microfluidic Valves Using a Hydrogel Molding Method.

Science.gov (United States)

Sugiura, Yusuke; Hirama, Hirotada; Torii, Toru

2015-08-24

In this paper, a method for fabricating a microfluidic valve made of polydimethylsiloxane (PDMS) using a rapid prototyping method for microchannels through hydrogel cast molding is discussed. Currently, the valves in microchannels play an important role in various microfluidic devices. The technology to prototype microfluidic valves rapidly is actively being developed. For the rapid prototyping of PDMS microchannels, a method that uses a hydrogel as the casting mold has been recently developed. This technique can be used to prepare a three-dimensional structure through simple and uncomplicated methods. In this study, we were able to fabricate microfluidic valves easily using this rapid prototyping method that utilizes hydrogel cast molding. In addition, we confirmed that the valve displacement could be predicted within a range of constant pressures. Moreover, because microfluidic valves fabricated using this method can be directly observed from a cross-sectional direction, we anticipate that this technology will significantly contribute to clarifying fluid behavior and other phenomena in microchannels and microfluidic valves with complex structures.

Casting methods

Science.gov (United States)

Marsden, Kenneth C.; Meyer, Mitchell K.; Grover, Blair K.; Fielding, Randall S.; Wolfensberger, Billy W.

2012-12-18

A casting device includes a covered crucible having a top opening and a bottom orifice, a lid covering the top opening, a stopper rod sealing the bottom orifice, and a reusable mold having at least one chamber, a top end of the chamber being open to and positioned below the bottom orifice and a vacuum tap into the chamber being below the top end of the chamber. A casting method includes charging a crucible with a solid material and covering the crucible, heating the crucible, melting the material, evacuating a chamber of a mold to less than 1 atm absolute through a vacuum tap into the chamber, draining the melted material into the evacuated chamber, solidifying the material in the chamber, and removing the solidified material from the chamber without damaging the chamber.

FY 1999 report on the results of the research and development project for new industry creating type industrial science and technology. Innovated casting simulation technology; 1999 nendo kakushinteki chuzo simulation gijutsu seika hokokusho

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-03-01

Described herein are the results of the FY1999 research and development project, implemented for development of the casting process simulation technologies, with the objectives to improve productivity, reduce cost, reduce the development periods, and so on for casting. For development of the mold filling and solidification process simulation programs, the fundamental algorithm and basic designs of the three-dimensional programs are developed, and the two-dimensional programs are made on a trial basis. For the analysis of the two-dimensional mold filling models, it is found that gas entrapment may occur even in the case of sand mold casting with low permeability. For development of the solidification structure and defect formation simulation programs, the basic investigations are done for the fundamental algorithms to simulate the solidification structures and porosity defects, and for the mechanisms involved in formation of these defects. These efforts lead to adoption of the CA method, and development of the algorithms for reducing CPU time and computational memory requirements by the active block method. For development of the related measurement techniques, the construction plans and specifications of an electromagnetic levitation furnace are investigated for the underground microgravity test center. (NEDO)

Investigation of the tensile properties of continuous steel wire-reinforced gray cast iron composite

Energy Technology Data Exchange (ETDEWEB)

Akdemir, Ahmet [Department of Mechanical Engineering, Selcuk University, Konya (Turkey); Kus, Recai [Department of Mechanical Education, Selcuk University, Konya (Turkey); Simsir, Mehmet, E-mail: msimsir@cumhuriyet.edu.tr [Department of Metallurgical and Materials Engineering, Cumhuriyet University, Kayseri Yolu 7. Km, 58140 Sivas (Turkey)

2011-04-25

Research highlights: {yields} Metal matrix composite (MMC) is an important structural material. {yields} Gray cast irons as a matrix material in MMC have more advantages than other cast irons. {yields} Interface greatly determines the mechanical properties of MMC. {yields} Interface formed by diffusion of carbon atoms. {yields} While decarburizing takes place in gray cast iron, carburiszing takes place in steel near the interface. - Abstract: The aim of the present study was to improve the tensile properties of gray cast iron by reinforcing the material with a steel wire. The composite was produced by sand mold casting, and the specimens were normalized by applying heat treatments at 800 deg. C, 850 deg. C, and 900 deg. C. Tension tests were conducted on gray cast iron and composite specimens, and the microstructure of the specimens was examined with an optical microscope. The fracture surface of the tension test specimens was examined with a scanning electron microscope (SEM), and graphite-free transition regions with high degrees of hardness were observed due to the diffusion of carbon from the cast iron to the steel wire. The microstructure of the transition region (fine pearlitic phase with partially dissolved graphite flakes) and the bond quality in the transition region increased the tensile properties of cast iron composites. Also, it is concluded that the tensile properties of gray cast iron increased with an increase in the normalization temperature.

Investigation of the tensile properties of continuous steel wire-reinforced gray cast iron composite

International Nuclear Information System (INIS)

Akdemir, Ahmet; Kus, Recai; Simsir, Mehmet

2011-01-01

Research highlights: → Metal matrix composite (MMC) is an important structural material. → Gray cast irons as a matrix material in MMC have more advantages than other cast irons. → Interface greatly determines the mechanical properties of MMC. → Interface formed by diffusion of carbon atoms. → While decarburizing takes place in gray cast iron, carburiszing takes place in steel near the interface. - Abstract: The aim of the present study was to improve the tensile properties of gray cast iron by reinforcing the material with a steel wire. The composite was produced by sand mold casting, and the specimens were normalized by applying heat treatments at 800 deg. C, 850 deg. C, and 900 deg. C. Tension tests were conducted on gray cast iron and composite specimens, and the microstructure of the specimens was examined with an optical microscope. The fracture surface of the tension test specimens was examined with a scanning electron microscope (SEM), and graphite-free transition regions with high degrees of hardness were observed due to the diffusion of carbon from the cast iron to the steel wire. The microstructure of the transition region (fine pearlitic phase with partially dissolved graphite flakes) and the bond quality in the transition region increased the tensile properties of cast iron composites. Also, it is concluded that the tensile properties of gray cast iron increased with an increase in the normalization temperature.

Improved ceramic slip casting technique. [application to aircraft model fabrication

Science.gov (United States)

Buck, Gregory M. (Inventor); Vasquez, Peter (Inventor)

1993-01-01

A primary concern in modern fluid dynamics research is the experimental verification of computational aerothermodynamic codes. This research requires high precision and detail in the test model employed. Ceramic materials are used for these models because of their low heat conductivity and their survivability at high temperatures. To fabricate such models, slip casting techniques were developed to provide net-form, precision casting capability for high-purity ceramic materials in aqueous solutions. In previous slip casting techniques, block, or flask molds made of plaster-of-paris were used to draw liquid from the slip material. Upon setting, parts were removed from the flask mold and cured in a kiln at high temperatures. Casting detail was usually limited with this technique -- detailed parts were frequently damaged upon separation from the flask mold, as the molded parts are extremely delicate in the uncured state, and the flask mold is inflexible. Ceramic surfaces were also marred by 'parting lines' caused by mold separation. This adversely affected the aerodynamic surface quality of the model as well. (Parting lines are invariably necessary on or near the leading edges of wings, nosetips, and fins for mold separation. These areas are also critical for flow boundary layer control.) Parting agents used in the casting process also affected surface quality. These agents eventually soaked into the mold, the model, or flaked off when releasing the case model. Different materials were tried, such as oils, paraffin, and even an algae. The algae released best, but some of it remained on the model and imparted an uneven texture and discoloration on the model surface when cured. According to the present invention, a wax pattern for a shell mold is provided, and an aqueous mixture of a calcium sulfate-bonded investment material is applied as a coating to the wax pattern. The coated wax pattern is then dried, followed by curing to vaporize the wax pattern and leave a shell

Optimization of the investment casting process

Directory of Open Access Journals (Sweden)

M. Martinez-Hernandez

2012-04-01

Full Text Available Rapid prototyping is an important technique for manufacturing. This work refers to the manufacture of hollow patterns made of polymeric materials by rapid prototyping technologies for its use in the preparation of ceramic molds in the investment casting process. This work is focused on the development of a process for manufacturing patterns different from those that currently exist due to its hollow interior design, allowing its direct use in the fabrication of ceramic molds; avoiding cracking and fracture during the investment casting process, which is an important process for the foundry industry.

The effects of casting speed on steel continuous casting process

Energy Technology Data Exchange (ETDEWEB)

Sadat, Mohammad; Honarvar Gheysari, Ali; Sadat, Saeid [Islamic Azad University, Department of Mechanics, Mashhad Branch, Mashhad (Iran, Islamic Republic of)

2011-12-15

A three dimensional simulation of molten steel flow, heat transfer and solidification in mold and ''secondary cooling zone'' of Continuous Casting machine was performed with consideration of standard k-{epsilon} model. For this purpose, computational fluid dynamics software, FLUENT was utilized. From the simulation standpoint, the main distinction between this work and preceding ones is that, the phase change process (solidification) and flow (turbulent in mold section and laminar in secondary cooling zone) have been coupled and solved jointly instead of dividing it into ''transient heat conduction'' and ''steady fluid flow'' that can lead to more realistic simulation. Determining the appropriate boundary conditions in secondary cooling zone is very complicated because of various forms of heat transfer involved, including natural and forced convection and simultaneous radiation heat transfer. The main objective of this work is to have better understanding of heat transfer and solidification in the continuous casting process. Also, effects of casting speed on heat flux and shell thickness and role of radiation in total heat transfer is discussed. (orig.)

High Temperature Thermal Properties of Bentonite Foundry Sand

Directory of Open Access Journals (Sweden)

Krajewski P.K.

2015-06-01

Full Text Available The paper presents results of measuring thermal conductivity and heat capacity of bentonite foundry sand in temperature range ambient - 900­­°C. During the experiments a technical purity Cu plate was cast into the green-sand moulds. Basing on measurements of the mould temperature field during the solidification of the casting, the temperature relationships of the measured properties were evaluated. It was confirmed that water vaporization strongly influences thermal conductivity of the moulding sand in the first period of the mould heating by the poured casting.

MATERIALS FOR PRODUCTION OF METAL MOLDS

Directory of Open Access Journals (Sweden)

A. Ju. Jakovlev

2007-01-01

Full Text Available The influence of alloying with manganese, chromium, nickel, copper and molybdenum on mechanical characteristics and thermocyclic endurance of grayed steel and possibility of its application for metal casting molds is investigated.

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.

Large Eddy Simulation of Transient Flow, Solidification, and Particle Transport Processes in Continuous-Casting Mold

Science.gov (United States)

Liu, Zhongqiu; Li, Linmin; Li, Baokuan; Jiang, Maofa

2014-07-01

The current study developed a coupled computational model to simulate the transient fluid flow, solidification, and particle transport processes in a slab continuous-casting mold. Transient flow of molten steel in the mold is calculated using the large eddy simulation. An enthalpy-porosity approach is used for the analysis of solidification processes. The transport of bubble and non-metallic inclusion inside the liquid pool is calculated using the Lagrangian approach based on the transient flow field. A criterion of particle entrapment in the solidified shell is developed using the user-defined functions of FLUENT software (ANSYS, Inc., Canonsburg, PA). The predicted results of this model are compared with the measurements of the ultrasonic testing of the rolled steel plates and the water model experiments. The transient asymmetrical flow pattern inside the liquid pool exhibits quite satisfactory agreement with the corresponding measurements. The predicted complex instantaneous velocity field is composed of various small recirculation zones and multiple vortices. The transport of particles inside the liquid pool and the entrapment of particles in the solidified shell are not symmetric. The Magnus force can reduce the entrapment ratio of particles in the solidified shell, especially for smaller particles, but the effect is not obvious. The Marangoni force can play an important role in controlling the motion of particles, which increases the entrapment ratio of particles in the solidified shell obviously.

Modeling of TiAl Alloy Grating by Investment Casting

Directory of Open Access Journals (Sweden)

Yi Jia

2015-12-01

Full Text Available The investment casting of TiAl alloys has become the most promising cost-effective technique for manufacturing TiAl components. This study aimed to investigate a series of problems associated with the investment casting of TiAl alloys. The mold filling and solidification of this casting model were numerically simulated using ProCAST. Shrinkage porosity was quantitatively predicted by a built-in feeding criterion. The results obtained from the numerical simulations were compared with experiments, which were carried out on Vacuum Skull Furnace using an investment block mold. The investment casting of TiAl grating was conducted for verifying the correctness and feasibility of the proposed method. The tensile test results indicated that, at room temperature, the tensile strength and elongation were approximately 675 MPa and 1.7%, respectively. The microstructure and mechanical property of the investment cast TiAl alloy were discussed.

40 CFR 464.20 - Applicability; description of the copper casting subcategory.

Science.gov (United States)

2010-07-01

... copper casting subcategory. 464.20 Section 464.20 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS METAL MOLDING AND CASTING POINT SOURCE CATEGORY Copper Casting Subcategory § 464.20 Applicability; description of the copper casting subcategory. The...

40 CFR 464.30 - Applicability; description of the ferrous casting subcategory.

Science.gov (United States)

2010-07-01

... ferrous casting subcategory. 464.30 Section 464.30 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS METAL MOLDING AND CASTING POINT SOURCE CATEGORY Ferrous Casting Subcategory § 464.30 Applicability; description of the ferrous casting subcategory. The...

40 CFR 464.10 - Applicability; description of the aluminum casting subcategory.

Science.gov (United States)

2010-07-01

... aluminum casting subcategory. 464.10 Section 464.10 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS METAL MOLDING AND CASTING POINT SOURCE CATEGORY Aluminum Casting Subcategory § 464.10 Applicability; description of the aluminum casting subcategory. The...

40 CFR 464.40 - Applicability; description of the zinc casting subcategory.

Science.gov (United States)

2010-07-01

... casting subcategory. 464.40 Section 464.40 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS METAL MOLDING AND CASTING POINT SOURCE CATEGORY Zinc Casting Subcategory § 464.40 Applicability; description of the zinc casting subcategory. The provisions of this...

Retorting of bituminous sands

Energy Technology Data Exchange (ETDEWEB)

Chaney, P E; Ince, R W; Mason, C M

1872-09-26

This method of recovering oil from mined tar sands involves forming compacted tar sands pieces by special conditioning treatment that provides low internal permeability. The compacted pieces are then retorted in fixed bed form. The conditioning treatment can involve rolling of preformed pellets, compaction in a mold or pressure extrusion. Substantial collapsing of the bed during retorting is avoided. (9 claims) (Abstract only - original article not available from T.U.)

Preparation of thin actinide metal disks using a multiple disk casting technique

International Nuclear Information System (INIS)

Conner, W.V.

1975-01-01

A casting technique has been developed for preparing multiple actinide metal disks which have a minimum thickness of 0.006 inch. This technique was based on an injection casting procedure which utilizes the weight of a tantalum metal rod to force the molten metal into the mold cavity. Using the proper mold design and casting parameters, it has been possible to prepare ten 1/2 inch diameter neptunium or plutonium metal disks in a single casting, This casting technique is capable of producing disks which are very uniform. The average thickness of the disks from a typical casting will vary no more than 0.001 inch and the variation in the thickness of the individual disks will range from 0.0001 to 0.0005 inch. (Auth.)

Preparation of thin actinide metal disks using a multiple disk casting technique

International Nuclear Information System (INIS)

Conner, W.V.

1976-01-01

A casting technique has been developed for preparing multiple actinide metal disks which have a minimum thickness of 0.006 inch. This technique was based on an injection casting procedure which utilizes the weight of a tantalum metal rod to force the molten metal into the mold cavity. Using the proper mold design and casting parameters, it has been possible to prepare ten 1/2 inch diameter neptunium or plutonium metal disks in a single casting. This casting technique is capable of producing disks which are very uniform. The average thickness of the disks from a typical casting will vary no more than 0.001 inch and the variation in the thickness of the individual disks will range from 0.0001 to 0.0005 inch. (author)

Effects of aluminum and copper chill on mechanical properties and microstructures of Cu-Zn-Al alloys with sand casting

Science.gov (United States)

Ardhyananta, Hosta; Wibisono, Alvian Toto; Ramadhani, Mavindra; Widyastuti, Farid, Muhammad; Gumilang, Muhammad Shena

2018-04-01

Cu-Zn-Al alloy is one type of brass, which has high strength and high corrosion resistant. It has been applied on ship propellers and marine equipment. In this research, the addition of aluminum (Al) with variation of 1, 2, 3, 4% aluminum to know the effect on mechanical properties and micro structure at casting process using a copper chill and without copper chill. This alloy is melted using furnace in 1100°C without holding. Then, the molten metal is poured into the mold with copper chill and without copper chill. The speciment of Cu-Zn-Al alloy were chracterized by using Optical Emission Spectroscopy (OES), Metallography Test, X-Ray Diffraction (XRD), Hardness Test of Rockwell B and Charpy Impact Test. The result is the addition of aluminum and the use of copper chill on the molds can reduce the grain size, increases the value of hardness and impact.

The development of lab-on-a-chip fabricated from two molds

Science.gov (United States)

Pramuanjaroenkij, A.; Bunta, J.; Thiangpadung, J.; Sansaradee, S.; Kamsopa, P.; Sodsai, S.; Vichainsan, S.; Wongpanit, K.; Maturos, T.; Lomas, T.; Tuantranont, A.; Cetin, B.; Phankhoksoong, S.; Tongkratoke, A.

2018-01-01

Development of diagnostic technique of microfluidic or lab-on-a-chip (LOCs) is currently of great interest for researchers and inventors for their many advantages. It can be used as a real laboratory was many ways to help to the diagnosis faster. This research aims to develop Polydimethylsiloxane (PDMS) lab-on-a-chip (LOCs) which were produced from different molds; the silicon wafer mold and the stainless mold to investigate the flow of the biological sample as the flow in nanochannels. In addition, this research proposes a means to leakage and the blockage of the channel flow. The experimental results were found that the LOCs casted from the silicon wafer mold sandwiched by both the plasma cleaner machine and H shaped acrylic sheets showed leakages around the electrode areas because the first new electrodes were too thick, the proper thickness of the nickel electrode was at 0.05 millimeters. The LOCs casted from the stainless mold were inserted by the nickel electrodes produced by the from the prototype shaped electroplating process; this LOCs using nickel plated electrodes 2 times to make a groove on the nickel electrode backsides when pouring the PDMS into the LOCs casted from the stainless mold. It was found that PDMS was able to flow under the nickel electrode and the PDMS sheet could stick with the glass slide smoothly. In conclusion, it was possible to develop these LOC designs and new electrode fabrications continually under helps from Micro-Electro-Mechanical system, Thailand National Electronics and Computer Technology Center, since causes of the LOC problems were found, and demonstrated the feasibility of developing the LOCs for chemical detection and disease diagnostics.

Application of the lattice Boltzmann method for simulation of the mold filling process in the casting industry

Science.gov (United States)

Szucki, Michal; Suchy, J. S.; Lelito, J.; Malinowski, P.; Sobczyk, J.

2017-12-01

The aim of this work is the development of the lattice Boltzmann model for simulation of the mold filling process. The authors present a simplified approach to the modeling of liquid metal-gas flows with particular emphasis on the interactions between these phases. The boundary condition for momentum transfer of the moving free surface to the gaseous phase is shown. Simultaneously, the method for modeling influence of gas back pressure on a position and shape of the interfacial boundary is explained in details. The problem of the lattice Boltzmann method (LBM) stability is also analyzed. Since large differences in viscosity of both fluids are a source of the model instability, the so-called fractional step (FS) method allowing to improve the computation stability is applied. The presented solution is verified on the bases of the available reference data and the results of experiments. It is shown that the model describes properly such effects as: gas bubbles formation and air back pressure, accompanying liquid-gas flows in the casting mold. At the same time the proposed approach is easy to be implemented and characterized by a lower demand of operating memory as compared to typical LBM models of two-phase flows.

Direct Cast U-6Nb – 2017 Progress on Cylindrical Castings

Energy Technology Data Exchange (ETDEWEB)

Aikin, Jr., Robert M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2017-10-04

This report describes work to further develop a sound technical basis and best practices for mold design and process parameters for the Direct Casting of U-6wt%Nb components. One major challenge to the production of U-6Nb components is the propensity for niobium segregation during casting and solidification. This is especially true for cylindrical castings where the vertical side walls allow flotation of Nb resulting in severe inverse macrosegregation. In this work, a small (120 mm diameter by 180 mm tall) and large cylinder (250 mm diameter by 310 mm tall) are examined with a focus on reducing, or eliminating, niobium segregation. It is demonstrated that counter gravity casting (top-to-bottom solidification) can be used to minimize segregation in the small cylinder. Attempts to counter gravity cast the large cylinder were unsuccessful, in large part due to size limitations of the current furnace. A path forward for casting of the large cylinders is discussed.

Micro-structure and Air-tightness of Squeeze Casting Motor housing for New Energy Vehicle

Science.gov (United States)

Jiang, Y. F.; Kang, Z. Q.; Jiang, W. F.; Wang, K. W.; Sha, D. L.; Li, M. L.; Sun, J.

2018-05-01

In order to improve the performance of automobile parts, the influence of squeeze casting process parameters on casting defects, material structure and air-tightness of aluminum alloy motor housing for new energy vehicle was studied. The results show that the density of the castings increases with the increase in pressure and mold temperature. With increase in pouring temperature, it increases first and then decreases. Pressure has the greatest influence on the density of the castings. Under a certain pressure, with moderate increase in casting temperature and mold temperature, the grain growth begins to increase; the dendrites become less, the new α - Al grains are spherical and granular, the micro-structure is uniform. Also, with increase in pressure, this effect is more pronounced, the air-tightness of castings improve. In conclusion, when the pressure is 110MPa, pouring temperature is 680° C, mold temperature is 280° C, pressure holding for 30s, and punch speed of 0.1m/s, there is no clear shrinkage in the casting, the structure is uniform, the qualified rate of air-tightness of production reaches 86%, and the performance is excellent.

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.

Influence green sand system by core sand additions

Directory of Open Access Journals (Sweden)

N. Špirutová

2012-01-01

Full Text Available Today, about two thirds of iron alloys casting (especially for graphitizing alloys of iron are produced into green sand systems with usually organically bonded cores. Separation of core sands from the green sand mixture is very difficult, after pouring. The core sand concentration increase due to circulation of green sand mixture in a closed circulation system. Furthermore in some foundries, core sands have been adding to green sand systems as a replacement for new sands. The goal of this contribution is: “How the green sand systems are influenced by core sands?”This effect is considered by determination of selected technological properties and degree of green sand system re-bonding. From the studies, which have been published yet, there is not consistent opinion on influence of core sand dilution on green sand system properties. In order to simulation of the effect of core sands on the technological properties of green sands, there were applied the most common used technologies of cores production, which are based on bonding with phenolic resin. Core sand concentration added to green sand system, was up to 50 %. Influence of core sand dilution on basic properties of green sand systems was determined by evaluation of basic industrial properties: moisture, green compression strength and splitting strength, wet tensile strength, mixture stability against staling and physical-chemistry properties (pH, conductivity, and loss of ignition. Ratio of active betonite by Methylene blue test was also determined.

Numerical simulation of stress-strain state of electrophoretic shell molds

Science.gov (United States)

Sviridov, A. V.; Odinokov, V. I.; Dmitriev, E. A.; Evstigneev, A. I.; Bashkov, O. V.

2017-10-01

In the foundry engineering, castings obtained in one-piece non-gas-generating high-refractory electrophoretic shell molds (ShM) by investment patterns (IP) have an increased rejects percentage associated with low deformation resistance and crack resistance of the SM at different stages of their formation and manufacturing. Crack resistance of the ShM based on IP depends mainly on their stress-strain state (SSS) at various stages of mold forming. SSS decrease significantly improves their crack resistance and decreases their rejects percentage of castings occurring due to clogging and surface defects. In addition, the known methods of decreasing the SSS are still poorly understood. Thus, current research trends are to determine SSS at each stage of ShM forming and develop the ways to decrease it. Theoretical predicting of crack formation in multiple-layer axisymmetric shell molds is given in the work [1], and SSS of multiple-layer axisymmetric shell molds is given in the work [2]. Monolayer electrophoretic ShM had a lack of concern in this field, thus it became an argument for the present workMathematical Model of ShM SSS

ASSESSMENT OF SURFACE FINISH AND DIMENSIONAL ACCURACY OF TOOLS MANUFACTURED BY METAL CASTING IN RAPID PROTOTYPING SAND MOULDS

OpenAIRE

Nyembwe, K.; De Beer, D. J.; Van der Walt, J. G.; Bhero, S.

2012-01-01

In this paper, an initial assessment of the quality parameters of the surface finish and dimensional accuracy of tools made by metal casting in rapid prototyping (RP) sand moulds is undertaken. A case study from a local tool room, dealing with the manufacturing of an aluminium die for the lost wax process, is employed. Modern techniques, including surface roughness analysis and three dimensional scanning, are used to determine and understand how each manufacturing step influences the final qu...

CASTING METHOD AND APPARATUS

Science.gov (United States)

Gray, C.F.; Thompson, R.H.

1958-10-01

An improved apparatus for the melting and casting of uranium is described. A vacuum chamber is positioned over the casting mold and connected thereto, and a rod to pierce the oxide skin of the molten uranium is fitted into the bottom of the melting chamber. The entire apparatus is surrounded by a jacket, and operations are conducted under a vacuum. The improvement in this apparatus lies in the fact that the top of the melting chamber is fitted with a plunger which allows squeezing of the oxide skin to force out any molten uranium remaining after the skin has been broken and the molten charge has been cast.

Deep UV patterning of acrylic masters for molding biomimetic dry adhesives

International Nuclear Information System (INIS)

Sameoto, D; Menon, C

2010-01-01

We present a novel fabrication method for the production of biomimetic dry adhesives that allows enormous variation in fiber shapes and sizes. The technology is based on deep-UV patterning of commercial acrylic with semi-collimated light available from germicidal lamps, and combined careful processing conditions, material selection and novel developer choices to produce relatively high-aspect-ratio fibers with overhanging caps on large areas. These acrylic fibers are used as a master mold for subsequent silicone rubber negative mold casting. Because the bulk acrylic demonstrates little inherent adhesion to silicone rubbers, the master molds created in this process do not require any surface treatments to achieve high-yield demolding of interlocked structures. Multiple polymers can be cast from silicone rubber negative molds and this process could be used to structure smart materials on areas over multiple square feet. Using direct photopatterning of acrylic allows many of the desired structures for biomimetic dry adhesives to be produced with relative ease compared to silicon-based molding processes, including angled fibers and hierarchical structures. Optimized fiber shapes for a variety of polymers can be produced using this process, and adhesion measurements on a well-characterized polyurethane, ST-1060, are used to determine the effect of fiber geometry on adhesion performance

Mechanical properties of as-cast microalloyed steels produced via investment casting

International Nuclear Information System (INIS)

Najafi, H.; Rassizadehghani, J.; Norouzi, S.

2011-01-01

Tensile and room temperature Charpy V-notch impact tests were used to evaluate the variations in the as-cast mechanical properties of a low-carbon steel produced via shell mould investment casting and containing combinations of vanadium, niobium and titanium. Tensile results indicate that the yield strength and ultimate tensile strength (UTS) have increased up to respectively 615 MPa and 770 MPa due to the fine-scale microalloy precipitates in the microalloyed samples. Room temperature impact test results show that while addition of vanadium individually has not changed the impact energy, Nb has decreased it considerably. However, examination of fracture surfaces reveals that all microalloyed samples have failed by transgranular cleavage. Based on the transmission electron microscope (TEM) studies, it seems that carbonitrides being greater than 50 nm in size and formed along prior austenite grain boundaries before γ transformation are responsible for the observed reduction in impact energies and brittle fracture. In comparison to sand mould casting, the yield and UTS obtained from investment casting are superior. Furthermore, although the impact energies of Nb-containing alloys are approximately the same as those obtained from sand moulds, the impact energy of the alloy containing only vanadium has improved considerably.

Modeling of TiAl Alloy Grating by Investment Casting

OpenAIRE

Yi Jia; Shulong Xiao; Jing Tian; Lijuan Xu; Yuyong Chen

2015-01-01

The investment casting of TiAl alloys has become the most promising cost-effective technique for manufacturing TiAl components. This study aimed to investigate a series of problems associated with the investment casting of TiAl alloys. The mold filling and solidification of this casting model were numerically simulated using ProCAST. Shrinkage porosity was quantitatively predicted by a built-in feeding criterion. The results obtained from the numerical simulations were compared with experimen...

A poly(dimethylsiloxane)-coated flexible mold for nanoimprint lithography

International Nuclear Information System (INIS)

Lee, Nae Yoon; Kim, Youn Sang

2007-01-01

In this paper, we introduce an anti-adhesion poly(dimethylsiloxane) (PDMS)-coated flexible mold and its applications for room-temperature imprint lithography. The flexible mold is fabricated using an ultraviolet-curable prepolymer on a flexible substrate, and its surface is passivated with a thin layer of PDMS to impart an anti-adhesion property. The highly flexible mold enables conformal contact with a substrate on which a low-viscosity polymer resist is spin-cast in a thin layer. Large-area imprinting is then realized at room temperature under significantly reduced pressure. The mold was durable even after repetitive imprinting of over 200 times. Also, we show a double imprinting on the substrate with a PDMS-coated replica polymeric mold having 500 nm line patterns. This enables the formation of matrix patterns with varying feature heights in less than 7 min

Steel castings of valves for nuclear power station

International Nuclear Information System (INIS)

Yamasaki, Yutaka

1975-01-01

The manufacturing of the steel castings of valves for nuclear power plants is reported. The report is divided in six parts. The first part describes the reliability of the steel castings of valves for nuclear power plants. Particular attention must be paid to larger diameter and lower pressure rating for the valves in nuclear power plants than those in thermal power plants. The second part describes the characteristics of steel casting quality, defects and their cause. The defects that may be produced in steel castings are as follows: (a) cavities caused by the insufficient supply of molten steel, (b) sand bites caused by the mold destruction due to thermal shock, and (c) pinholes caused by the gas absorption of molten steel. The third part describes the clarification of quality level and the measures quality project. Gaseous defects and the indications detected by magnetic powder test are attributed to electric furnace steel making. In particular, the method to minimize gas content is important. The fourth part describes the quality control of manufacturing processes. In practice, thirteen semi-automatic testers using gamma radiation are employed. A full automatic inspection plant having capacity of 20,000 radiographs per month is under design. The fifth part describes a quality warrant system. A check sheet system concerning quality and safety is employed in all work shops. The reliability of all testers and measuring instruments as well as the skill of workmen are examined periodically. The seventh part deals with future problems. The manufacturing plan must be controlled so that non-destructive inspection becomes the main means for quality control. (Iwakiri, K.)

Production of Steel Casts in Two-Layer Moulds with Alkaline Binders Part 2. Facing sand with the alkaline organic binder REZOLIT

Directory of Open Access Journals (Sweden)

M. Holtzer

2011-04-01

Full Text Available This paper constitutes the second part of the article concerning the implementation of the two-layer mould technology for steel casts inZ.M. POMET. The results of the laboratory examinations of the backing sand with the inorganic binder RUDAL were presented in thefirst part of the paper. Whereas in the second part the results of the laboratory testing of the facing sand with the alkaline resin REZOLITare given. The technology of two-layer moulds was already implemented in Z.M. POMET within the target project. Examples of castingsmade in this technology are shown in the final part of this paper.

Replication of specifically microstructured surfaces in A356-alloy via lost wax investment casting

International Nuclear Information System (INIS)

Ivanov, Todor; Bührig-Polaczek, Andreas; Vroomen, Uwe; Hartmann, Claudia; Holtkamp, Jens; Gillner, Arnold; Bobzin, Kirsten; Bagcivan, Nazlim; Theiss, Sebastian

2011-01-01

A common way of realizing microstructural features on metallic surfaces is to generate the designated pattern on each single part by means of microstructuring technologies such as e.g. laser ablation, electric discharge machining or micromilling. The disadvantage of these process chains is the limited productivity due to the additional processing of each part. The approach of this work is to replicate microstructured surfaces from a master pattern via lost wax investment casting in order to reach a higher productivity. We show that microholes of different sizes ( 15–22 µm at depths of 6–14 µm) can be replicated in AlSi7Mg-alloy from a laser-structured master pattern via investment casting. However, some loss of molding accuracy during the multi-stage molding process occurs. Approximately 50% of the original microfeature's heights are lost during the wax injection step. In the following process step of manufacturing a gypsum-bonded mold, a further loss in the surface quality of the microfeatures can be observed. In the final process step of casting the aluminum melt, the microfeatures are filled without any loss of molding accuracy and replicate the surface quality of the gypsum mold. The contact angle measurements of ultrapure water on the cast surfaces show a decrease in wettability on the microstructured regions (75°) compared to the unstructured region (60°)

Development of magnesium semi-solid injection molding; Magnesium han`yoyu shashutsu seikei gijutsu no kaihatsu

Energy Technology Data Exchange (ETDEWEB)

Sakamoto, K; Sakate, N; Ishida, K; Yamamoto, Y; Nishimura, K [Mazda Motor Corp., Hiroshima (Japan)

1997-10-01

Magnesium semi-solid injection molding is safety and clean process. We have investigated influence of molding conditions on mechanical properties and dimension accuracy of products by semi-solid injection molding. As a result it was proved that the accuracy of products by this process is superior to die casting. This advantage as well as better mechanical properties can be utilized for net shape molding of some automobile parts. 4 refs., 8 figs., 3 tabs.

Manufacturability evaluation for molded parts using fictitious physical models, and its application in topology optimization

OpenAIRE

Sato, Yuki; Yamada, Takayuki; Izui, Kazuhiro; Nishiwaki, Shinji

2017-01-01

Manufacturing methods using molds, such as casting and injection molding, are widely used in industries. A basic requirement when using such manufacturing methods is that design engineers must design products so that they incorporate certain geometrical features that allow the mold parts to be removed from the created solid object. In the present study, we propose a manufacturability evaluation method especially adapted for the use of molds. To evaluate the manufacturability, we introduce fic...

Development of High-Performance Cast Crankshafts. Final Technical Report

Energy Technology Data Exchange (ETDEWEB)

Bauer, Mark E [General Motors, Detroit, MI (United States)

2017-03-31

simulations with existing materials models to optimize crankshaft cost and performance. Prototype crankshafts of the final design were to be produced and validated using laboratory bench testing and on-engine durability testing. ICME process simulation tools were used to investigate a broad range of processing concepts. These concepts included casting orientation, various mold and core materials, and various filling and feeding strategies. Each crankshaft was first simulated without gating and risers, which is termed natural solidification. The natural solidification results were used as a baseline for strategy development of each concept. Casting process simulations and ICME tools were proven to be reasonable predictors of real world results. Potential alloys were developed that could meet the project material property goals with appropriate normalization and temper treatments. For the alloys considered, post-normalization temper treatments proved to be necessary to achieve the desired yield strengths and elongations and appropriate heat treatments were designed using ICME tools. The experimental data of all the alloys were analyzed in combination with ICME tools to establish chemistry-process-structure relations. Several GM small gas engine (SGE) crankshafts were successfully cast in sand molds using two different sprue, runner, gate, riser, chill designs. These crankshafts were cast in two different steel alloys developed during the project, but casting finishing (e.g. riser removal) remains a cost challenge. A long list of future work was left unfinished when this project was unexpectedly terminated.

Casting traceability with direct part marking using reconfigurable pin-type tooling based on paraffin–graphite actuators

DEFF Research Database (Denmark)

Vedel-Smith, Nikolaj Kjelgaard; Lenau, Torben Anker

2012-01-01

Green sand moulding machines for cast iron foundries are presently unable to uniquely identify individual castings. An insert tool concept is developed and tested via incremental mock-up development. The tool is part of the pattern plate and changes shape between each moulding, thus giving each...... mould a unique ID by embossing a Data Matrix symbol into the sand. In the process of producing the mould, each casting can be given a unique (DPM), enabling part tracking throughout the casting's life cycle. Sand embossing is achieved with paraffin-actuated reconfigurable pin-type tooling under...... simulated processing conditions. The marker geometry limitations have been tested using static symbol patterns, both for sand embossing and actual casting marking. The marked castings have successfully been identified with decoding software. The study shows that the function of each element...

ANN modelling for the determination of moulding sand matrix grain size

Directory of Open Access Journals (Sweden)

J. Jakubski

2011-10-01

Full Text Available One of the modern methods of the production optimisation are artificial neural networks. Neural networks are gaining broader and broader application in the foundry industry, among others for controlling melting processes in cupolas and in arc furnaces, for designing castings and supply systems, for controlling moulding sand processing, for predicting properties of cast alloys or selecting parameters of pressure castings. An attempt to apply neural networks for controlling the quality of bentonite moulding sands is presented in this paper. This is the assessment method of sands suitability by means of detecting correlations between their individual parameters. The presented investigations were obtained by using the Statistica 9.0 program. The aim of the investigations was to select the neural network suitable for prediction the moulding sand matrix grain size on the basis of the determined sand properties such as: permeability, compactibility, and compressive strength.

Flop casting of nuclear materials for advanced fuel cycle research - 5247

International Nuclear Information System (INIS)

Swift, A.J.; Koury, D.J.; Czerwinski, K.R.; Vollmer, J.M.

2015-01-01

Full text of publication follows. Next generation fast reactor designs of nuclear reactors utilizing metallic fuel are being developed as an alternative fuel cycle option in an effort to reduce carbon emissions. Metallic fuel systems are attractive because of their high thermal conductivity, fissile atom density, and inherent safety. Metallic fuel systems are also being investigated because of their potential to reach high burnups. The increased targeted burnups for metallic fuels lead to higher concentrations of actinides, lanthanides, and other fission products, which alter the fuel properties and impact the performance of the fuel. Before designs can be implemented, the fission product concentrations must be studied at variable fuel geometries and stages of fuel burnup. Arc flop casting serves as a viable option for casting alloys as the molds can be tailored to fit design specific requirements while cutting costs in time-consuming machining. Arc casting is done as the final preparation step in a small arc furnace with an argon or 5% hydrogen-argon atmosphere after the sample has been subsequently melted, overturned, and re-melted. The flop casting mold is then fitted to the chamber as needed and the previously prepared sample is quickly hit with a high current arc causing the molten metal to fill the copper mold. The U-Zr-Pu system will serve as the basis for this research as it has been extensively studied since the 1950 years, although flop casting can be adapted to any metallic fuel system. Multiple U-Zr-Pu with varying fission product concentrations alloys, Technetium metal, and Plutonium alloys have been flop cast based on burnup calculations. Prepared samples were cast using different molds and dimensions, then characterized by Scanning Electron Microscopy, X-ray diffraction, and Thermogravimetric Analysis. The goal of this research is to test and develop flop casting techniques for the production of metallic fuel alloys applicable for various stages and

Relationship between casting modulus and grain size in cast A356 aluminium alloys

International Nuclear Information System (INIS)

Niklas, A; Abaunza, U; Fernández-Calvo, A I; Lacaze, J

2012-01-01

Microstructure of Al-Si alloy castings depends most generally on melt preparation and on the cooling rate imposed by the thermal modulus of the component. In the case of Al-Si alloys, emphasis is put during melt preparation on refinement of pro-eutectic (Al) grains and on modification of the Al-Si eutectic. Thermal analysis has been used since long to check melt preparation before casting, i.e. by analysis of the cooling curve during solidification of a sample cast in an instrumented cup. The conclusions drawn from such analysis are however valid for the particular cooling conditions of the cups. It thus appeared of interest to investigate how these conclusions could extrapolate to predict microstructure in complicated cast parts showing local changes in the solidification conditions. For that purpose, thermal analysis cups and instrumented sand and die castings with different thermal moduli and thus cooling rates have been made, and the whole set of cooling curves thus recorded has been analysed. A statistical analysis of the characteristic features of the cooling curves related to grain refinement in sand and die castings allowed determining the most significant parameters and expressing the cube of grain size as a polynomial of these parameters. After introduction of a further parameter quantifying melt refining an excellent correlation, with a R 2 factor of 0.99 was obtained.

Characterisation of Q and T steel pole shoes manufactured by sand casting; Charakterisierung mit Sandguss hergestellter Polschuhe aus verguetetem Stahl

Energy Technology Data Exchange (ETDEWEB)

Asensio-Lozano, J.; Alvarez-Antolin, J.F. [Oviedo Univ. (Spain). Dept. of Materials Science and Metallurgical Engineering; Panta-Mesones, J.T. [National Univ. of Trujillo, La Libertad (Peru). Faculty of Mines, Metallurgy and Materials; Vander-Voort, G.F. [Buehler Ltd., Lake Bluff, IL (United States)

2008-04-15

This paper presents a study of the microstructural and mechanical characterization of the GS 35 CrMoV 10 4 alloy employed in the manufacture of sand-cast pole shoes for 4-pole synchronous electric power generators working at a frequency of 60 Hz. In addition, the most appropriate treatment for ensuring compliance with the technical specifications defined in DIN Standard No. 1.7755 has been designed. (orig.)

Analysis of Meniscus Fluctuation in a Continuous Casting Slab Mold

Science.gov (United States)

Zhang, Kaitian; Liu, Jianhua; Cui, Heng; Xiao, Chao

2018-03-01

A water model of slab mold was established to analyze the microscopic and macroscopic fluctuation of meniscus. The fast Fourier transform and wavelet entropy were adopted to analyze the wave amplitude, frequency, and components of fluctuation. The flow patterns under the meniscus were measured by using particle image velocimetry measurement and then the mechanisms of meniscus fluctuation were discussed. The results reflected that wavelet entropy had multi-scale and statistical properties, and it was suitable for the study of meniscus fluctuation details both in time and frequency domain. The basic wave, frequency of which exceeding 1 Hz in the condition of no mold oscillation, was demonstrated in this work. In fact, three basic waves were found: long-wave with low frequency, middle-wave with middle frequency, and short-wave with high frequency. In addition, the upper roll flow in mold had significant effect on meniscus fluctuation. When the position of flow impinged was far from the meniscus, long-wave dominated the fluctuation and the stability of meniscus was enhanced. However, when the velocity of flow was increased, the short-wave dominated the meniscus fluctuation and the meniscus stability was decreased.

Mathematical model of the crystallizing blank`s thermal state at the horizontal continuous casting machine

Directory of Open Access Journals (Sweden)

Kryukov Igor Yu.

2017-01-01

Full Text Available Present article is devoted to the development of the mathematical model, which describes thermal state and crystallization process of the rectangular cross-section blank while continious process of extraction from a horysontal continious casting machine (HCCM.The developed model took cue for the heat-transfer properties of non-iron metal teeming; its temperature on entry to the casting mold; cooling conditions of blank in the carbon molds in the presence of a copper water cooler. Besides, has been considered the asymmetry of heat interchange from blank`s head and drag at mold, coming out from fluid contraction and features of the horizontal casting mold. The developed mathematical model allows to determine alterations in crystallizing blank of the following factors with respect to time: temperature pattern of crystallizing blank under different technical working regimes of HCCM; boundaries of solid two-phase field and liquid two-phase filed; blank`s thickness variation under shrinkage of the ingot`s material

Neutron radiography inspection of investment castings

International Nuclear Information System (INIS)

Richards, W.J.; Barrett, J.R.; Springgate, M.E.; Shields, K.C.

2004-01-01

Investment casting, also known as the lost wax process, is a manufacturing method employed to produce near net shape metal articles. Traditionally, investment casting has been used to produce structural titanium castings for aero-engine applications with wall thickness less than 1 in (2.54 cm). Recently, airframe manufacturers have been exploring the use of titanium investment casting to replace components traditionally produced from forgings. Use of titanium investment castings for these applications reduces weight, cost, lead time, and part count. Recently, the investment casting process has been selected to produce fracture critical structural titanium airframe components. These airframe components have pushed the traditional inspection techniques to their physical limits due to cross sections on the order of 3 in (7.6 cm). To overcome these inspection limitations, a process incorporating neutron radiography (n-ray) has been developed. In this process, the facecoat of the investment casting mold material contains a cocalcined mixture of yttrium oxide and gadolinium oxide. The presence of the gadolinium oxide, allows for neutron radiographic imaging (and eventual removal and repair) of mold facecoat inclusions that remain within these thick cross sectional castings. Probability of detection (POD) studies have shown a 3x improvement of detecting a 0.050x0.007 in 2 (1.270x0.178 mm 2 ) inclusion of this cocalcined material using n-ray techniques when compared to the POD using traditional X-ray techniques. Further, it has been shown that this n-ray compatible mold facecoat material produces titanium castings of equal metallurgical quality when compared to the traditional materials. Since investment castings can be very large and heavy, the neutron radiography facilities at the University of California, Davis McClellan Nuclear Radiation Center (UCD/MNRC) were used to develop the inspection techniques. The UCD/MNRC has very unique facilities that can handle large parts

Optimization of casting defects analysis with supply chain in cast iron foundry process

Directory of Open Access Journals (Sweden)

C. Narayanaswamy

2016-10-01

Full Text Available Some of the foundries are in need of meeting production targets and due to the urgency they ignore the rejections. The objective of this paper is to analyze the various defects, [1] from molding process in a cast iron foundry. The Failure Mode Effects Analysis (FMEA in quality control [2-6] with suitable supply chain for mold making process considering rejection rates are identified and analyzed in terms of Risk Priority Number (RPN to prioritize the attention for each of the problem. The optimum levels of selected parameters [7] are obtained in this analysis.

The role of water in slip casting

Science.gov (United States)

Mccauley, R. A.; Phelps, G. W.

1984-01-01

Slips and casting are considered in terms of physical and colloidal chemistry. Casting slips are polydisperse suspensions of lyophobic particles in water, whose degree of coagulation is controlled by interaction of flocculating and deflocculating agents. Slip casting rate and viscosity are functions of temperature. Slip rheology and response to deflocculating agents varies significantly as the kinds and amounts of colloid modifiers change. Water is considered as a raw material. Various concepts of water/clay interactions and structures are discussed. Casting is a de-watering operation in which water moves from slip to cast to mold in response to a potential energy termed moisture stress. Drying is an evaporative process from a free water surface.

ELABORATION OF MANAGEMENT PLAN OF SOLID WASTE FROM SMALL CAST IRON FOUNDRIES

Directory of Open Access Journals (Sweden)

Carlos Alberto Mendes Moraes

2013-12-01

Full Text Available The foundry industry contributes to society meeting the demand of metal scrap recycling, but, at the same time, it brings a high risk of environmental impact for its many potentially pollutant wastes. Among these, there are slag and used foundry sand (cold cure molding. Through a survey about the production process of a small cast iron company, the collected data was compiled to determine the organizational setting in terms of generation and segregation of waste. From a complete environmental diagnosis carried out in eight small cast iron foundries, one of them was chosen to be a basis for the elaboration of an industrial solid waste management plan, which is becoming necessary to know and manage the generation of wastes qualitatively and quantitatively. A data assessment about the production process was carried out and compiled to determine the actual organizational scenario. As a result of that, it is possible to create a favorable environment to develop tools for environmental impacts prevention, which will permit the migration for more complex actions on the direction of more efficient process, cleaner production, and internal and external recycling of exceeding materials.

Effect of SiO2 concentration in silica sol on interface reaction during titanium alloy investment casting

Directory of Open Access Journals (Sweden)

Ya-meng Wei

2018-01-01

Full Text Available Using silica sol as a binder for titanium investment casting is very attractive due to its good stability and reasonable cost as compared with yttrium sol and zirconium sol. However, the mechanism of interface reaction in the related system remains unclear. In this investigation, the interface reaction between Y2O3-SiO2 (Y-Si shell mold and titanium alloys was studied. A group of shell molds were prepared by using Y2O3 sand and silica sol with different contents of SiO2. Ti-6Al-4V alloy was cast under vacuum by gravity casting through cold crucible induction melting (CCIM method. Scanning electron microscopy (SEM and energy dispersive x-ray spectroscopy (EDS were employed to characterize the micromorphology and composition of the reaction area, respectively. X-ray photoelectron spectroscopy (XPS was used to confirm the valence state of relevant elements. White light interferometer (WLI was used to obtain the surface topography of Y-Si shells. The results show that the thickness of reaction layers is below 3 μm when the SiO2 content of silica sol is below 20wt.%. Whereas, when the SiO2 content increases to 25wt.%, the thickness of the reaction layer increases sharply to about 15 μm. There is a good balance between chemical inertness and mechanical performance when the SiO2 content is between 15 and 20wt.%. Moreover, it was found that the distribution of SiO2 and the roughness at the surface of the shell are the key factors that determine the level of reaction.

Microstructural evolution in Mg-rich Mg-Zn-Y alloys

International Nuclear Information System (INIS)

Biswas, T.; Ranganathan, S.; Nair, S.; Bajargan, G.

2005-01-01

Mg-rich Mg-Zn-Y alloys with nominal compositions Mg 97 Zn 1 Y 2 , Mg 97 Zn 2 Y 1 , Mg 92 Zn 6.5 Y 1.5 and Mg 97-x Zn 1 Y 2 Zr x have been chosen for the present study. These alloys are prepared by using sand casting mold. The sand cast alloys are remelted and subjected to copper mold casting and melt spinning techniques. The effect of cooling rate on microstructures was studied. It is observed that the size of the precipitates decreases with an increase of cooling rate. The formation of nano precipitates results in higher strength of the alloy as compared to the conventional alloys. The microstructures of melt spun ribbons are compared with RS/PM (rapidly solidified power metallurgy) Mg 97 Zn 1 Y 2 alloy, obtained from a different source. (author)

Standardization of the process of smelting for sands with self-forgeling resins in the Military Industry Santa Bárbara Factory

Directory of Open Access Journals (Sweden)

Lina Consuelo Carvajal-Fernández

2014-12-01

Full Text Available This article describes the standardization of the smelting process for sands with self-forgeling resins in the Military Industry Santa Barbara Factory. The molding process was studied in the Smelter for six months, to set standards for workforce and raw materials, so that would allow truthfully evaluate the costs per kilogram of casting. 41 pieces of civil and military sectors throughout the development of the project were worked. Finally both standards were evaluated, labor as raw material for different parts, with results was evidenced improved process, essentially in workforce, while in raw material standards did not show significantly change, in this case is corroborated that existing ones are applicable to the process

Material properties of Al-Si-Cu aluminium alloy produced by the rotational cast technology

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Muhammad Syahid

2017-03-01

Full Text Available The aim of the present study is to explore microstructural and mechanical properties of cast Al-Si-Cu aluminum alloy (ADC12. To obtain excellent material properties, the cast Al alloys were produced by an originally developed mold rotational machine, namely liquid aluminum alloy is solidified during high speed rotating. The casting process was conducted under various casting conditions, in which the following factors were altered, e.g., melt temperature, metal mold temperature and different rotational speed. Microstructural characteristics were examined by direct observation using an optical microscope and a scanning electron microscope (SEM, and the secondary dendrite arm spacing of alpha-Al phase (SDAS and the size of Si eutectic phase were identified. Mechanical properties were investigated by micro-hardness and tensile tests. Rotation speed and melt temperature were directly attributed to the SDAS, and severe shear stress arising from the rotation made fine and complicated grain structure, leading to the high mechanical properties. The extent of the shear stress was altered depending on the area of the sample due to the different shear stress. Furthermore, high melt temperature and high rotational speed decrease the size of Si eutectic phases. The high mechanical properties were detected for the cast samples produced by the casting condition as follows: melt temperature 700oC, mold temperature 400oC and rotation speed 400 rpm

Casting Freedom, 1860-1862

Science.gov (United States)

Social Education, 2005

2005-01-01

Thomas Crawford, an American Sculptor, created the full-size figure of Freedom in clay. Molds were made, from which a full-size positive plaster model was cast in five main sections. This model is on view today in the basement rotunda of the Russell Senate Office Building. Clark Mills was a self-taught American sculptor with experience in casting…

MouldingSandDB – a modern database storing moulding sands properties research results

Directory of Open Access Journals (Sweden)

J. Jakubski

2011-01-01

Full Text Available The complexity of foundry processes requires the use of modern, advanced IT tools for optimization, storage and analysis of t echnicaldata. Properties of moulding and core sands that are collected in research laboratories, manufacturers, and finally in the foundries, are not in use later on. It seems important to create a database that will allow to use the results stored, along with the possibility of searching according to set criteria, adjusted to casting practice. This paper presents part of the database named „MouldingSandDB”, which allows to collect and search data for synthetic moulding sands.

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...... by measuring the heating curves. The viscosity of the coating, moisture content and the permeability of the cores were evaluated. The surface quality of the castings was investigated using SEM and OM. The results show that the moisture content of the cores affected the permeability. In furan cores the vapour...... 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...

Dominância coronariana em corações humanos em moldes por corrosão Coronary dominance patterns in the human heart investigated by corrosion casting

Directory of Open Access Journals (Sweden)

Décio Cavalet Soares Abuchaim

2009-12-01

Full Text Available OBJETIVO: Esse trabalho tem como objetivo analisar os padrões de dominância circulatória de corações humanos, o número de ramos que a artéria coronária direita fornece ao ventrículo esquerdo, o número de ramos que a artéria coronária esquerda fornece ao direito e a presença de anastomoses intercoronarianas, com sua localização e frequência. MÉTODOS: Foram produzidos 25 moldes de corações submetidos à instilação de acrílico colorido e posterior corrosão com ácido clorídrico, no Laboratório de Cirurgia Experimental da FURB. Peças com lesões e cicatrizes não foram usadas. RESULTADOS: Os corações pertenciam a indivíduos de ambos os sexos, sendo 17 (68% de indivíduos do sexo masculino, com idade média de 40,2 anos (15 a 70 anos. A dominância direita ocorreu em 18 (72% peças, com 1, 2, 3 e 4 ramos em 2, 14, 2 e 1 moldes, respectivamente; a dominância esquerda foi observada em 5 (20% casos, com 1 ramo em 4 moldes e 2 em 1 molde; e a dominância balanceada foi verificada em 2 (8% moldes. Houve diferença significativa entre a dominância direita e esquerda (α > 5%, direita e balanceada (α > 5% e sem significância entre esquerda e balanceada (α OBJECTIVES: The aim of this work was to analyze the dominance patterns of the circulation of the human heart, the number of branches from the right coronary artery to the left ventricle, the number of branches from the left coronary artery to the right ventricle and the frequency and location of intercoronary anastomoses. METHODS: Casts were made of 25 hearts by the injection of colored acrylic resin and subsequent corrosion using hydrochloric acid at the experimental surgery laboratory of Furb. Specimens with lesions or scars were discarded. RESULTS: The hearts, from both men (17 - 68% and women (8 - 32%, had a mean age of 40.2 (15 to 70 years-old. Right dominance occurred in 18 (72% subjects, with 1, 2, 3 and 4 branches leading to the left ventricle in 2, 14, 2 and 2

Optimization design of a gating system for sand casting aluminium A356 using a Taguchi method and multi-objective culture-based QPSO algorithm

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Wen-Jong Chen

2016-04-01

Full Text Available This article combined Taguchi method and analysis of variance with the culture-based quantum-behaved particle swarm optimization to determine the optimal models of gating system for aluminium (Al A356 sand casting part. First, the Taguchi method and analysis of variance were, respectively, applied to establish an L27(38 orthogonal array and determine significant process parameters, including riser diameter, pouring temperature, pouring speed, riser position and gating diameter. Subsequently, a response surface methodology was used to construct a second-order regression model, including filling time, solidification time and oxide ratio. Finally, the culture-based quantum-behaved particle swarm optimization was used to determine the multi-objective Pareto optimal solutions and identify corresponding process conditions. The results showed that the proposed method, compared with initial casting model, enabled reducing the filling time, solidification time and oxide ratio by 68.14%, 50.56% and 20.20%, respectively. A confirmation experiment was verified to be able to effectively reduce the defect of casting and improve the casting quality.

Fabrication of hierarchically structured superhydrophobic PDMS surfaces by Cu and CuO casting

Science.gov (United States)

Migliaccio, Christopher P.; Lazarus, Nathan

2015-10-01

Poly(dimethylsiloxane) (PDMS) films decorated with hierarchically structured pillars are cast from large area copper and copper oxide negative molds. The molds are fabricated using a single patterning step and electroplating. The process of casting structured PDMS films is simpler and cheaper than alternatives based on deep reactive ion etching or laser roughening of bulk silicone. Texture imparted to the pillars from the mold walls renders the PDMS films superhydrophobic, with the contact angle/hysteresis of the most non-wetting surfaces measuring 164°/9° and 158°/10° for surfaces with and without application of a low surface energy coating. The usefulness of patterned PDMS films as a "self-cleaning" solar cell module covering is demonstrated and other applications are discussed.

Casting characteristics of Al-Mg alloy 535 cast in permanent moulds

International Nuclear Information System (INIS)

Fasoyinu, F.A.; Thomson, J.; Cousineau, D.; Castles, T.; Sahoo, M.

2002-01-01

Aluminum alloy 535 could be used for automotive and marine applications because of its good corrosion resistance against mild alkaline and salt spray exposure. The majority of components from this alloy are usually produced by sand casting because it is prone to hot shortness and has poor fluidity when poured in permanent moulds. In an attempt to improve its castability in permanent moulds, casting characteristics such as casting fluidity and hot tear resistance have been studied. In addition, the effectiveness of titanium, boron, scandium, zirconium and a combination of selected elements from this group as grain refiners were evaluated. It s shown that alloy 535 exhibits good casting fluidity when poured with adequate metal superheat and that there is significant improvement in hot tear resistance following grain refinement. (author)

Stress and Friction Distribution around Slab Corner in Continuous Casting Mold with Different Corner Structures

Science.gov (United States)

Yu, Sheng; Long, Mujun; Chen, Huabiao; Chen, Dengfu; Liu, Tao; Duan, Huamei; Cao, Junsheng

2018-02-01

The non-uniform friction and thermal stress in the mold are important as causes of the transverse cracks around strand corner. To analyze the stress distribution features around strand corner, a three-dimensional thermo-elastoplastic finite-element mold model with different corner structures (right-angle, big-chamfer, multi-chamfer, and fillet) was established. The temperature field in the mold was indirectly coupled through a three-dimensional fluid flow and heat transfer model. In addition, the non-uniform mold friction stress loaded on the strand surface was calculated through a friction model. The results show that the stress distribution on the shell is similar to the temperature distribution. The stress concentration appears in the strand corner and the lower part of wide face. The friction stress enhances the corner stress around the edge of the air-gap. For chamfered molds, the stress around the corner between the wide face and chamfer face is larger than that between the narrow face and chamfer face. Around the corner region, both the stress peak and the area of the large stress zone of the right-angle strand are the largest, while those of big-chamfered, multi-chamfered, and fillet strands decrease in that order. The stress peak position of the chamfered strands is closer to the mold exit than that of the right-angle strand. Compared with the use of the right-angle mold, the application of chamfered molds is able to reduce the stress concentration around the strand corner.

Stress and Friction Distribution around Slab Corner in Continuous Casting Mold with Different Corner Structures

Science.gov (United States)

Yu, Sheng; Long, Mujun; Chen, Huabiao; Chen, Dengfu; Liu, Tao; Duan, Huamei; Cao, Junsheng

2018-06-01

The non-uniform friction and thermal stress in the mold are important as causes of the transverse cracks around strand corner. To analyze the stress distribution features around strand corner, a three-dimensional thermo-elastoplastic finite-element mold model with different corner structures (right-angle, big-chamfer, multi-chamfer, and fillet) was established. The temperature field in the mold was indirectly coupled through a three-dimensional fluid flow and heat transfer model. In addition, the non-uniform mold friction stress loaded on the strand surface was calculated through a friction model. The results show that the stress distribution on the shell is similar to the temperature distribution. The stress concentration appears in the strand corner and the lower part of wide face. The friction stress enhances the corner stress around the edge of the air-gap. For chamfered molds, the stress around the corner between the wide face and chamfer face is larger than that between the narrow face and chamfer face. Around the corner region, both the stress peak and the area of the large stress zone of the right-angle strand are the largest, while those of big-chamfered, multi-chamfered, and fillet strands decrease in that order. The stress peak position of the chamfered strands is closer to the mold exit than that of the right-angle strand. Compared with the use of the right-angle mold, the application of chamfered molds is able to reduce the stress concentration around the strand corner.

Engineering design of centrifugal casting machine

Science.gov (United States)

Kusnowo, Roni; Gunara, Sophiadi

2017-06-01

Centrifugal casting is a metal casting process in which metal liquid is poured into a rotating mold at a specific temperature. Given round will generate a centrifugal force that will affect the outcome of the casting. Casting method is suitable in the manufacture of the casting cylinder to obtain better results. This research was performed to design a prototype machine by using the concept of centrifugal casting. The design method was a step-by-step systematic approach in the process of thinking to achieve the desired goal of realizing the idea and build bridges between idea and the product. Design process was commenced by the conceptual design phase and followed by the embodiment design stage and detailed design stage. With an engineering design process based on the method developed by G. E. Dieter, draft prototype of centrifugal casting machine with dimension of 550×450×400 mm, ¼ HP motor power, pulley and belt mechanism, diameter of 120-150mm, simultaneously with the characteristics of simple casting product, easy manufacture and maintenance, and relatively inexpensive, was generated.

Castability of Ti-6Al-7Nb alloy for dental casting

OpenAIRE

Wang, Tie Jun; 小林, 郁夫; 土居, 壽; 米山, 隆之

1999-01-01

Castability of Ti-6Al-7Nb alloy, CP Ti, and Co-Cr alloy was examined for mesh type and plate type specimens. The casting was carried out with a pressure type casting machine and commercial molding material. The castability of the mesh type specimen was evaluated in terms of the number of cast segments (castability index), and that of the plate type was evaluated by the area of the speci­men (casting rate). X-ray images processed by a digital imaging technique were used to identify the casting...

Influence of reaction chamber shape on cast-iron spheroidization process in-mold

Directory of Open Access Journals (Sweden)

S. Pietrowski

2010-01-01

Full Text Available This paper presents a results concerning the influence of reaction chamber shape on cast – iron spheroidization process in form. The volume of the tested reaction chambers was about 118000mm3. Reaction chambers in the shape of: rectangular, cylinder and spherical cap were examined. It has been shown that the best graphite spheroidizing process was provided by spherical cap chamber shape. The reaction of cast – iron with magnesium in reaction chamber depends on the flow of cast – iron in the chamber. In rectangular and cylinder shape chambers proceed the impact of diphase stream on flat bottom wall. It causes the creation on its surface film, called: cast – iron “film”, where single grains of magnesium master alloy exist. The largest part of master alloy is drifted by liquid cast – iron to the top and only there graphite spheroidization process proceed. In the spherical cap shape reaction chamber, as a result of rotation movement of liquid cast – iron throughout its volume, graphite spheroidization process proceed. Apart from the reaction chamber shape, applying of mixing chamber ensure full cast – iron spheroidization process.

APPLICATION OF EXOTHERMIC PLUGS AT PRODUCTION OF STEEL CASTING IS THE WAY TO ECONOMY

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V. M. Gatsuro

2008-01-01

Full Text Available It is shown that application of exothermic plugs allows to decrease steel intensity of casting mold, labor intensiveness for trim, expenses for melting of 1 ton of good casting, material expenses for burden materials.

Reclaimability of the spent sand mixture – sand with bentonite – sand with furfuryl resin

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J. Dańko

2011-04-01

Full Text Available Introduction of new binding materials and new technologies of their hardening in casting moulds and cores production requires theapplication of reclamation methods adequate to their properties as well as special devices realizing tasks. The spent sands circulationsystem containing the same kind of moulding and core sands is optimal from the point of view of the expected reclamation results.However, in the face of a significant variability of applied technologies and related to them various reclamation methods, the need - of theobtained reclamation products assessment on the grounds of systematic criteria and uniform bases – arises, with a tendency of indicatingwhich criteria are the most important for the given sand system. The reclaimability results of the mixture of the spent moulding sand withGeko S bentonite and the spent core sand with the Kaltharz 404U resin hardened by acidic hardener 100 T3, are presented in the paper.Investigations were performed with regard to the estimation of an influence of core sands additions (10 –25% on the reclaimed materialquality. Dusts and clay content in the reclaim, its chemical reaction (pH and ignition loss were estimated. The verification of the reclaiminstrumental assessment was performed on the basis of the technological properties estimation of moulding sand with bentonite, where the reclaimed material was used as a matrix.

Temperature and microstructure characteristics of silumin casting AlSi9 made with investment casting method

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S. Pietrowski

2011-07-01

Full Text Available This work presents the research result of the temperature distribution and the microstructure in certain parts of the field-glass body frame casting made from silumin AlSi9 using the investment casting method in the ceramic mould. It was proved that the highest temperature of the silumin appears in the sprue in which the silumin is in the liquid-solid state, though the process of silumin crystallization in the casting is finished. It was stated that in certain elements of the casting the side opposite to the runner crystallizes and cools fastest. The differences in the rate of crystalline growth and cooling of certain casting elements cause differ- ent microstructure in them which can also influence the mechanic properties.It is necessary to state that the temperature of the initial heating of the ceramic mold equal to 60oC guarantees obtaining of the castings without defects and of little porosity. Incomplete modification of the silumin with strontium causes silica precipitation to appear close to the spherical ones.

The Strength of Moulding Sand Consisting of a Mixture of Bentonite, Tapioca Flour, and Sago Flour as a New Binder Formula to Improve the Quality of Al-Si Cast Alloy

Directory of Open Access Journals (Sweden)

Andoko Andoko

2017-08-01

Full Text Available The major factors determining the quality of sand casting products are the base sand and the composition of the sand mould and the binding material. In the foundry industry, the most commonly used binder for creating sand moulds is bentonite. However, the price of bentonite is likely to keep rising. This study aimed at discovering a new binder formula associated with the effect of binder composition i.e. bentonite, tapioca flour, and sago flour on the basis of its mechanical and physical properties. The new formula was expected to be a better binder in the production of sand moulds, resulting in high-quality casting products with minimal defects. Moreover, it is probable to be much more economical than bentonite. This research focused on testing the moulding sand composition with a number of different binders, i.e. bentonite, tapioca flour, and sago flour, each in a different proportion. The mixture of the moulding sand with each of the three binders will be tested in terms of its mechanical properties including compressive, shear, and tensile strength. Based on the test results, sago flour has the highest dry compressive strength of 28.6 N/cm2, whereas bentonite has the highest wet compressive strength, i.e. 11.83 N/cm2 and the highest wet shear strength i.e. 3.16 N/cm2. The binder with the highest dry shear strength is tapioca flour with 18.16 N/cm2. Regarding the tensile strength value, bentonite has the highest wet tensile strength of 0.85 N/cm2, while sago flour has the highest dry tensile strength of 1.73 N/cm2.

Flow Dynamics of green sand in the DISAMATIC moulding process using Discrete element method (DEM)

International Nuclear Information System (INIS)

Hovad, E; Walther, J H; Thorborg, J; Hattel, J H; Larsen, P

2015-01-01

The DISAMATIC casting process production of sand moulds is simulated with DEM (discrete element method). The main purpose is to simulate the dynamics of the flow of green sand, during the production of the sand mould with DEM. The sand shot is simulated, which is the first stage of the DISAMATIC casting process. Depending on the actual casting geometry the mould can be geometrically quite complex involving e.g. shadowing effects and this is directly reflected in the sand flow during the moulding process. In the present work a mould chamber with “ribs” at the walls is chosen as a baseline geometry to emulate some of these important conditions found in the real moulding process. The sand flow is simulated with the DEM and compared with corresponding video footages from the interior of the chamber during the moulding process. The effect of the rolling resistance and the static friction coefficient is analysed and discussed in relation to the experimental findings. (paper)

Effect of flask vibration time on casting integrity, Surface Penetration and Coating Inclusion in lost foam casting of Al-Si Alloy

International Nuclear Information System (INIS)

Karimian, Majid; Idris, M. H.; Ourdjini, A.; Muthu, Kali

2011-01-01

The paper presents the result of an experimental investigation conducted on medium aluminum silicon alloy casting- LM6, using no-vacuum assisted lost foam casting process. The study is directed for establishing the relationship between the flask vibrations times developed for molded sample on the casting integrity, surface penetration and coating inclusion defects of the casting. Four different flask vibration times namely 180, 120, 90 and 60 sec. were investigated. The casting integrity was investigated in terms of fulfilling in all portions and edges. The surface penetration was measured using optical microscope whilst image analyzer was used to quantify the percentage of coating inclusion in the casting. The results show that vibration time has significant influence on the fulfilling as well as the internal integrity of the lost foam casting. It was found that the lower vibration time produced comparatively sound casing.

Low Cost Al-Si Casting Alloy As In-Situ Composite for High Temperature Applications

Science.gov (United States)

Lee, Jonathan A.

2000-01-01

A new aluminum-silicon (Al-Si) alloy has been successfully developed at NASA- Marshall Space Flight Center (MSFC) that has significant improvement in tensile and fatigue strength at elevated temperatures (500 F-700 F). The alloy offers a number of benefits such as light weight, high hardness, low thermal expansion and high surface wear resistance. In hypereutectic form, this alloy is considered as an in-situ Al-Si composite with tensile strength of about 90% higher than the auto industry 390 alloy at 600 F. This composite is very economically produced by using either conventional permanent steel molds or die casting. The projected material cost is less than $0.90 per pound, and automotive components such as pistons can be cast for high production rate using conventional casting techniques with a low and fully accounted cost. Key Words: Metal matrix composites, In-situ composite, aluminum-silicon alloy, hypereutectic alloy, permanent mold casting, die casting.

A 1-D Analytical Model for the Thermally Induced Stresses in the Mould Surface During Die Casting

DEFF Research Database (Denmark)

Hattel, Jesper; Hansen, Preben

1994-01-01

This paper presents an anlytically based method for predicting the normal stresses in a die mold surface exposed to a thermal load. A example of application of the method is the high-pressure di casting process where the surface stresses in critical cases lead to cracks. Expressions for the normal...... stresses as afunction of the thermal and mechanical properties have been developed for a casting both without and with a coating. Finally, the resulting relationships are derived and evaluated, with particular emphasis on the effect of the heat transfer coefficient between the casting and the mold....

Assessment of Computer Simulation Software and Process Data for High Pressure Die Casting of Magnesium

Energy Technology Data Exchange (ETDEWEB)

Sabau, Adrian S [ORNL; Hatfield, Edward C [ORNL; Dinwiddie, Ralph Barton [ORNL; Kuwana, Kazunori [University of Kentucky; Viti, Valerio [University of Kentucky, Lexington; Hassan, Mohamed I [University of Kentucky, Lexington; Saito, Kozo [University of Kentucky

2007-09-01

Computer software for the numerical simulation of solidification and mold filling is an effective design tool for cast structural automotive magnesium components. A review of commercial software capabilities and their validation procedures was conducted. Aside form the software assessment, the program addressed five main areas: lubricant degradation, lubricant application, gate atomization, and heat transfer at metal mold interfaces. A test stand for lubricant application was designed. A sensor was used for the direct measurement of heat fluxes during lubricant application and casting solidification in graphite molds. Spray experiments were conducted using pure deionized water and commercial die lubricants. The results show that the sensor can be used with confidence for measuring heat fluxes under conditions specific to the die lube application. The data on heat flux was presented in forms suitable for use in HPDC simulation software. Severe jet breakup and atomization phenomena are likely to occur due to high gate velocities in HPDC. As a result of gate atomization, droplet flow affects the mold filling pattern, air entrapment, skin formation, and ensuing defects. Warm water analogue dies were designed for obtaining experimental data on mold filling phenomena. Data on break-up jet length, break-up pattern, velocities, and droplet size distribution were obtained experimentally and was used to develop correlations for jet break-up phenomena specific to die casting gate configurations.

Anodization of cast aluminium alloys produced by different casting methods

Directory of Open Access Journals (Sweden)

K. Labisz

2008-08-01

Full Text Available In this paper the usability of two casting methods, of sand and high pressure cast for the anodization of AlSi12 and AlSi9Cu3 aluminium cast alloys was investigated. With defined anodization parameters like electrolyte composition and temperature, current type and value a anodic alumina surface layer was produced. The quality, size and properties of the anodic layer was investigated after the anodization of the chosen aluminium cast alloys. The Alumina layer was observed used light microscope, also the mechanical properties were measured as well the abrasive wear test was made with using ABR-8251 equipment. The researches included analyze of the influence of chemical composition, geometry and roughness of anodic layer obtained on aluminum casts. Conducted investigations shows the areas of later researches, especially in the direction of the possible, next optimization anodization process of aluminum casting alloys, for example in the range of raising resistance on corrosion to achieve a suitable anodic surface layer on elements for increasing applications in the aggressive environment for example as materials on working building constructions, elements in electronics and construction parts in air and automotive industry.

Optimization of Casting Design Parameters on Fabrication of Reliable Semi-Solid Aluminum Suspension Control Arm

Science.gov (United States)

Ragab, Kh. A.; Bouaicha, A.; Bouazara, M.

2017-09-01

The semi-solid casting process has the advantage of providing reliable mechanical aluminum parts that work continuously in dynamic as control arm of the suspension system in automotive vehicles. The quality performance of dynamic control arm is related to casting mold and gating system designs that affect the fluidity of semi-solid metal during filling the mold. Therefore, this study focuses on improvement in mechanical performance, depending on material characterization, and casting design optimization, of suspension control arms made of A357 aluminum semi-solid alloys. Mechanical and design analyses, applied on the suspension arm, showed the occurrence of mechanical failures at unexpected weak points. Metallurgical analysis showed that the main reason lies in the difficult flow of semi-solid paste through the thin thicknesses of a complex geometry. A design modification procedure is applied to the geometry of the suspension arm to avoid this problem and to improve its quality performance. The design modification of parts was carried out by using SolidWorks design software, evaluation of constraints with ABAQUS, and simulation of flow with ProCast software. The proposed designs showed that the modified suspension arm, without ribs and with a central canvas designed as Z, is considered as a perfect casting design showing an increase in the structural strength of the component. In this case, maximum von Mises stress is 199 MPa that is below the yield strength of the material. The modified casting mold design shows a high uniformity and minim turbulence of molten metal flow during semi-solid casting process.

Selected parameters of moulding sands for designing quality control systems

Directory of Open Access Journals (Sweden)

J. Jakubski

2010-07-01

Full Text Available One of the modern methods of production optimisation are artificial neural networks. Neural networks owe their popularity to the fact thatthey are convenient tools, which can be utilised in a wide scope of problems. They are capable of reflecting complex functions. Especiallytheir non-linearity should be emphasised. They are gaining wider and wider application in the foundry industry, among others, to controlmelting processes in cupolas and arc furnaces, designing castings and supply systems, control of moulding sands treatments, prediction ofproperties of cast alloys as well as selecting die casting.An attempt of the application neural networks to the quality control of moulding sands with bentonite is presented in the paper. This isa method of assessing the suitability of moulding sands by finding correlations in between individual parameters, by means of artificialneural network systems. The presented investigations were performed with the application of the Statistica 8.0 program.The investigations were aimed at the selection of the proper kind of a neural network for prediction a sand moistness on the bases ofcertain moulding sand properties such as: permeability, compactibility and friability. These parameters – determined as sand moistness functions - were introduced as initial parameters.Application of the Statistica program allowed for an automatic selection of the most suitable network for the reflection of dependencies and interactions existing among the proposed parameters. The best results were obtained for unidirectional multi-layer perception network (MLP. The neural network sensitivity to individual moulding sand parameters was determined, which allowed to reject not important parameters when constructing the network.

Effective Laboratory Method of Chromite Content Estimation in Reclaimed Sands

Directory of Open Access Journals (Sweden)

Ignaszak Z.

2016-09-01

Full Text Available The paper presents an original method of measuring the actual chromite content in the circulating moulding sand of foundry. This type of material is applied for production of moulds. This is the case of foundry which most frequently perform heavy casting in which for the construction of chemical hardening mould is used, both the quartz sand and chromite sand. After the dry reclamation of used moulding sand, both types of sands are mixed in various ratios resulting that in reclaimed sand silos, the layers of varying content of chromite in mixture are observed. For chromite recuperation from the circulating moulding sand there are applied the appropriate installations equipped with separate elements generating locally strong magnetic field. The knowledge of the current ratio of chromite and quartz sand allows to optimize the settings of installation and control of the separation efficiency. The arduous and time-consuming method of determining the content of chromite using bromoform liquid requires operational powers and precautions during using this toxic liquid. It was developed and tested the new, uncomplicated gravimetric laboratory method using powerful permanent magnets (neodymium. The method is used in the production conditions of casting for current inspection of chromite quantity in used sand in reclamation plant.

Surface roughness characterization of cast components using 3D optical methods

DEFF Research Database (Denmark)

Nwaogu, Ugochukwu Chibuzoh; Tiedje, Niels Skat; Hansen, Hans Nørgaard

scanning probe image processor (SPIP) software and the results of the surface roughness parameters obtained were subjected to statistical analyses. The bearing area ratio was introduced and applied to the surface roughness analysis. From the results, the surface quality of the standard comparators...... is successfully characterised and it was established that the areal parameters are more informative for sand cast components. The roughness values of the standard visual comparators can serve as a control for the cast components and for order specifications in the foundry industry. A series of iron castings were...... made in green sand moulds and the surface roughness parameter (Sa) values were compared with those of the standards. Sa parameter suffices for the evaluation of casting surface texture. The S series comparators showed a better description of the surface of castings after shot blasting than the A series...

Methodology supporting production control in a foundry applying modern DISAMATIC molding line

Directory of Open Access Journals (Sweden)

Sika Robert

2017-01-01

Full Text Available The paper presents methodology of production control using statistical methods in foundry conditions, using the automatic DISAMATIC molding line. The authors were inspired by many years of experience in implementing IT tools for foundries. The authors noticed that there is a lack of basic IT tools dedicated to specific casting processes, that would greatly facilitate their oversight and thus improve the quality of manufactured products. More and more systems are installed in the ERP or CAx area, but they integrate processes only partially, mainly in the area of technology design and business management from finance and control. Monitoring of foundry processes can generate a large amount of process-related data. This is particularly noticeable in automated processes. An example is the modern DISAMATIC molding line, which integrates several casting processes, such as mold preparation, assembly, pouring or shake out. The authors proposed a methodology that supports the control of the above-mentioned foundry processes using statistical methods. Such an approach can be successfully used, for example, during periodic external audits. The mentioned methodology in the innovative DISAM-ProdC computer tool was implemented.

Development of casting technology and localization for a medical radioisotope transport cask

International Nuclear Information System (INIS)

Lee, Y. S.; Kim, H. S.; Jang, S. J.; Seo, K. S.; Kim, C. G.

2003-01-01

In order to localize the shielding casks for shipping medical isotopes, this research was carried out. The various casting factors such as the diameter of shielding casting, the temperature of melt and the temperature gradient of a mold were determined with the calculation results of solidification analysis computer code. Through the experiment, the manufacturing method of Ti core was developed to have no defects causing casting failure. As a results of casting experiment, depleted uranium shielding castings were successfully cast without any defect. Also as the results of the radiation shielding capability test, it was good enough to satisfied the standards of transport regulations

Rapid prototyping of biodegradable microneedle arrays by integrating CO2 laser processing and polymer molding

International Nuclear Information System (INIS)

Tu, K T; Chung, C K

2016-01-01

An integrated technology of CO 2 laser processing and polymer molding has been demonstrated for the rapid prototyping of biodegradable poly-lactic-co-glycolic acid (PLGA) microneedle arrays. Rapid and low-cost CO 2 laser processing was used for the fabrication of a high-aspect-ratio microneedle master mold instead of conventional time-consuming and expensive photolithography and etching processes. It is crucial to use flexible polydimethylsiloxane (PDMS) to detach PLGA. However, the direct CO 2 laser-ablated PDMS could generate poor surfaces with bulges, scorches, re-solidification and shrinkage. Here, we have combined the polymethyl methacrylate (PMMA) ablation and two-step PDMS casting process to form a PDMS female microneedle mold to eliminate the problem of direct ablation. A self-assembled monolayer polyethylene glycol was coated to prevent stiction between the two PDMS layers during the peeling-off step in the PDMS-to-PDMS replication. Then the PLGA microneedle array was successfully released by bending the second-cast PDMS mold with flexibility and hydrophobic property. The depth of the polymer microneedles can range from hundreds of micrometers to millimeters. It is linked to the PMMA pattern profile and can be adjusted by CO 2 laser power and scanning speed. The proposed integration process is maskless, simple and low-cost for rapid prototyping with a reusable mold. (paper)

Rapid prototyping of biodegradable microneedle arrays by integrating CO2 laser processing and polymer molding

Science.gov (United States)

Tu, K. T.; Chung, C. K.

2016-06-01

An integrated technology of CO2 laser processing and polymer molding has been demonstrated for the rapid prototyping of biodegradable poly-lactic-co-glycolic acid (PLGA) microneedle arrays. Rapid and low-cost CO2 laser processing was used for the fabrication of a high-aspect-ratio microneedle master mold instead of conventional time-consuming and expensive photolithography and etching processes. It is crucial to use flexible polydimethylsiloxane (PDMS) to detach PLGA. However, the direct CO2 laser-ablated PDMS could generate poor surfaces with bulges, scorches, re-solidification and shrinkage. Here, we have combined the polymethyl methacrylate (PMMA) ablation and two-step PDMS casting process to form a PDMS female microneedle mold to eliminate the problem of direct ablation. A self-assembled monolayer polyethylene glycol was coated to prevent stiction between the two PDMS layers during the peeling-off step in the PDMS-to-PDMS replication. Then the PLGA microneedle array was successfully released by bending the second-cast PDMS mold with flexibility and hydrophobic property. The depth of the polymer microneedles can range from hundreds of micrometers to millimeters. It is linked to the PMMA pattern profile and can be adjusted by CO2 laser power and scanning speed. The proposed integration process is maskless, simple and low-cost for rapid prototyping with a reusable mold.

A comparison between the dimensions of positive transtibial residual limb molds prepared by air pressure casting and weight-bearing casting methods.

Science.gov (United States)

Hajiaghaei, Behnam; Ebrahimi, Ismail; Kamyab, Mojtaba; Saeedi, Hassan; Jalali, Maryam

2016-01-01

Creating a socket with proper fit is an important factor to ensure the comfort and control of prosthetic devices. Several techniques are commonly used to cast transtibial stumps but their effect on stump shape deformation is not well understood. This study compares the dimensions, circumferences and volumes of the positive casts and also the socket comfort between two casting methods. Our hypothesis was that the casts prepared by air pressure method have less volume and are more comfortable than those prepared by weight bearing method. Fifteen transtibial unilateral amputees participated in the study. Two weight bearing and air pressure casting methods were utilized for their residual limbs. The diameters and circumferences of various areas of the residual limbs and positive casts were compared. The volumes of two types of casts were measured by a volumeter and compared. Visual Analogue Scale (VAS) was used to measure the sockets fit comfort. Circumferences at 10 and 15 cm below the patella on the casts were significantly smaller in air pressure casting method compared to the weight bearing method (p=0.00 and 0.01 respectively). The volume of the cast in air pressure method was lower than that of the weight bearing method (p=0.006). The amputees found the fit of the sockets prepared by air pressure method more comfortable than the weight bearing sockets (p=0.015). The air pressure casting reduced the circumferences of the distal portion of residual limbs which has more soft tissue and because of its snug fit it provided more comfort for amputees, according to the VAS measurements.

Manufacture of tube billets for fuel cans by vacuum centrifugal casting

International Nuclear Information System (INIS)

Zelenskij, V.F.; Neklyudov, I.M.; Chernyj, B.P.

1989-01-01

Vacuum device for induction melting with centrifugal casting in the ingot mold with rotation vertical or horisontal axis is presented. Removing and grinding of nonmetallic inclusions are realized by selection of casting conditions and of chemically active reducer, sound metal with high ductility is obtained. Data on micro- and macrostructure of casted tube billets made of 08Kh18N10T and 06Kh16H15M3B stainless steels, designed for manufacture of fuel cans are presented

The role and impact of 3D printing technologies in casting

Directory of Open Access Journals (Sweden)

Jin-wu Kang

2017-05-01

Full Text Available 3D printing is such a magical technology that it extends into almost every sector relating to manufacturing, not to mention casting production. In this paper, the past, present and future of 3D printing in the foundry sector are profoundly reviewed. 3D printing has the potential to supplement or partially replace the casting method. Today, some castings can be directly printed by metal powders, for example, titanium alloys, nickel alloys and steel parts. Meanwhile, 3D printing has found an unique position in other casting aspects as well, such as printing the wax pattern, ceramic shell, sand core, sand mould, etc. Most importantly, 3D printing is not just a manufacturing method, it will also revolutionize the design of products, assemblies and parts, such as castings, patterns, cores, moulds and shells in casting production. The solid structure of castings and moulds will be redesigned in future into truss or spatially open and skeleton structures. This kind of revolution is just sprouting, but it will bring unimaginable impact on manufacturing including casting production. Nobody doubts the potential of 3D printing technologies in manufacturing, but they do have limitations and drawbacks.

Multiphysics modeling of the steel continuous casting process

Science.gov (United States)

Hibbeler, Lance C.

This work develops a macroscale, multiphysics model of the continuous casting of steel. The complete model accounts for the turbulent flow and nonuniform distribution of superheat in the molten steel, the elastic-viscoplastic thermal shrinkage of the solidifying shell, the heat transfer through the shell-mold interface with variable gap size, and the thermal distortion of the mold. These models are coupled together with carefully constructed boundary conditions with the aid of reduced-order models into a single tool to investigate behavior in the mold region, for practical applications such as predicting ideal tapers for a beam-blank mold. The thermal and mechanical behaviors of the mold are explored as part of the overall modeling effort, for funnel molds and for beam-blank molds. These models include high geometric detail and reveal temperature variations on the mold-shell interface that may be responsible for cracks in the shell. Specifically, the funnel mold has a column of mold bolts in the middle of the inside-curve region of the funnel that disturbs the uniformity of the hot face temperatures, which combined with the bending effect of the mold on the shell, can lead to longitudinal facial cracks. The shoulder region of the beam-blank mold shows a local hot spot that can be reduced with additional cooling in this region. The distorted shape of the funnel mold narrow face is validated with recent inclinometer measurements from an operating caster. The calculated hot face temperatures and distorted shapes of the mold are transferred into the multiphysics model of the solidifying shell. The boundary conditions for the first iteration of the multiphysics model come from reduced-order models of the process; one such model is derived in this work for mold heat transfer. The reduced-order model relies on the physics of the solution to the one-dimensional heat-conduction equation to maintain the relationships between inputs and outputs of the model. The geometric

A Casting Yield Optimization Case Study: Forging Ram

DEFF Research Database (Denmark)

Kotas, Petr; Tutum, Cem Celal; Hattel, Jesper Henri

2010-01-01

This work summarizes the findings of multi-objective optimization of a gravity sand-cast steel part for which an increase of the casting yield via riser optimization was considered. This was accomplished by coupling a casting simulation software package with an optimization module. The benefits...... of this approach, recently adopted in foundry industry world wide and based on fully automated computer optimization, were demonstrated. First, analyses of filling and solidification of the original casting design were conducted in the standard simulation environment to determine potential flaws and inadequacies...

Quantification of Feeding Effects of Spot Feeding Ductile Iron Castings made in Vertically Parted Moulds

DEFF Research Database (Denmark)

Vedel-Smith, Nikolaj Kjelgaard; Tiedje, Niels Skat; Sällström, J.

In vertically parted molds it is traditionally difficult to feed heavy sections that cannot be reached by traditional side/top feeders or other conventional methods. This project aims at quantifying the effects of using molded-in ram-up spot feeders as a means of feeding isolated sections in cast...

Application of metal oxide refractories for melting and casting reactive metals

International Nuclear Information System (INIS)

Jessen, N.C. Jr.; Holcombe, C.E. Jr.; Townsend, A.B.

1979-01-01

Extensive investigations have been conducted to develop metal oxide refractories for containment of molten uranium and uranium alloys. Since uranium and uranium alloys are readily susceptable to the formation of complex oxides, carbides, nitrides, intermetallic compounds, and suboxide reactions, severe problems exist for the production of quality castings. These contamination reactions are dependent on temperature, pressure, and molten metal interfacial reactions. The need for high purity metals to meet specification repeatedly has resulted in the development of improved metal oxide refractories and sophisticated furnace controls. Applications of Y 2 O 3 for use as a crucible and mold coating, precision molds and cores, and high temperature castable ceramics are discussed. Experimental results on melt impurity levels, thermal controls during melting, surface interactions and casting quality are presented

Design optimization of clutch housing mold by fluid flow and solidification simulation

Energy Technology Data Exchange (ETDEWEB)

Hosseini, Seyedeh Maryam; Utlu, Zafer [Istanbul Aydin Univ., Istanbul (Turkmenistan)

2016-06-15

Aluminum die casting is so complex where flow momentum is critical matter in the mould filling process due the high velocity of the liquid metal. Actually, in complex parts the exact calculation of mould filling performance with using experimental knowledge is almost impossible. Aluminum die castings play a definitive role in the manufacturing of lightweight automobile bodies. Hence it is more essential today that these castings be produced with the high quality methods. In this condition the simulation is becoming more important in the designing procedure. This saves time and reduces the cost of the casting system design, which is an advantage of using simulation programs. Also, economical utilization of materials can be obtained when the quantity of test castings is decreased. This paper describes the advantages of the clutch housing die casting mold simulations to achieve better casting system design in High pressure die castings (HPDC). Filling analysis is used to determine the size and location of the gate as well as proper runner system design for ensuring a complete and balanced filling of the clutch housing part.

AN INTRODUCTION TO RAPID CASTING: DEVELOPMENT AND INVESTIGATION OF PROCESS CHAINS FOR SAND CASTING OF FUNCTIONAL PROTOTYPES

Directory of Open Access Journals (Sweden)

D. Dimitrov

2012-01-01

Full Text Available

ENGLISH ABSTRACT: This paper discusses the results obtained from studies on different Rapid Tooling process chains in order to improve the design and manufacture of foundry equipment that is used for sand casting of prototypes in final material. These prototypes are intended for functional and pre-production tests of vehicles. The Three Dimensional Printing process is used as core technology. Subsequently, while considering aspects such as time, cost, quality (accuracy and surface roughness, and tool life, a framework is presented for the evaluation and selection of the most suitable process chain in accordance with specific requirements. This research builds on an in-depth characterisation of the accuracy and repeatability of a 3D printing process.

AFRIKAANSE OPSOMMING: Hierdie artikel bespreek die resultate wat verkry is tydens studies op verskillende Snel-Gereedskapvervaardigingproseskettings wat ondersoek is teneinde die ontwerp en vervaardiging van sandgietgereedskap, om prototipes in finale materiaal te vervaardig, te verbeter. Die prototipes is bestem vir gebruik in funksionele- en voorproduksietoetse van voertuie. Die sogenaamde Driedimensionele Drukproses (3DP is as kerntegnologie aangewend. Gevolglik, na oorweging van aspekte soos tyd, koste, kwaliteit (akkuraatheid en oppervlakafwerking, en gereedskapleeftyd, is ’n raamwerk ontwikkel vir die evaluering en seleksie van die mees geskikte prosesketting met inagname van spesifieke vereistes. Hierdie navorsing bou op ’n diepgaande karakterisering van die akkuraatheids- en herhaalbaarheidsvermoë van ’n 3D drukproses.

Effect of rare earth element on microstructure formation and mechanical properties of thin wall ductile iron castings

International Nuclear Information System (INIS)

Choi, J.O.; Kim, J.Y.; Choi, C.O.; Kim, J.K.; Rohatgi, P.K.

2004-01-01

Ductile iron castings with 2, 3, 4, 6, 8, and 25 mm thickness and various amount of rare earth elements (RE) (from 0 to 0.04%), were cast in sand molds to identify the effects of sample thickness and the content of RE% on microstructural formation and selected mechanical properties. The effects of RE content and sample thickness on microstructural formation, including on graphite nodule count, graphite nodule shape, spherodization, and ferrite amount, were observed. The yield strength of the samples with RE within the range investigated were lower than those of the specimens without RE. The elongation was improved with the addition of RE up to 0.03% in ductile iron castings. The additions of 0.02% RE caused a smaller graphite nodule size and a higher number of graphite nodules than those in the specimen without RE at all levels of RE addition; the nodule count decreased with increase in section size. The chill zones were observed in the 2 mm thick samples, but were absent in the samples from castings which were thicker than 2 mm, irrespective of the addition of RE. The nodularity of graphite nodules improved due to the addition of 0.02-0.04% RE. The specimens with RE content up to 0.03% had a lower tensile strength and hardness, higher elongation than that of the specimens without RE. The ferrite content in all castings increased with additions of 0.02% RE. The tensile strengths of the 2 and 3 mm thick samples were also estimated using the relationship between strength and hardness, obtained from the data on the tensile strength and hardness of the 25 mm thick samples

Effects of Moisture Content on the Foundry Properties of Yola Natural Sand

Directory of Open Access Journals (Sweden)

Paul Aondona IHOM

2012-08-01

Full Text Available The effect of moisture content of Yola natural sand has been studied. The moisture content was varied from 1 to 9%. The effect of the moisture content on the green compression strength, green permeability and bulk density was investigated. Particle size distribution of the natural sand, the grain fineness number, average grain size, grain shape and the clay content of the natural sand were also studied. 5% moisture gave the optimum green compression strength of 118.6KN/m2. The dry compression strength increased with moisture content, an optimum value of 4000KN/m2 was obtained at 9% moisture. The Yola natural sand had a grain fineness number of 88.05AFS, average grain size of 335.78 microns and a clay content of 26%. A sand mixture containing 5% moisture was prepared and used to produce a test casting with aluminium scraps, the test casting was sound.

Pressing Speed, Specific Pressure and Mechanical Properties of Aluminium Cast

Directory of Open Access Journals (Sweden)

Gaspar S.

2016-06-01

Full Text Available Recent research in the process of aluminum alloy die castings production, which is nowadays deeply implemented into the rapidly growing automobile, shipping and aircraft industries, is aimed at increasing the useful qualitative properties of the die casting in order to obtain its high mechanical properties at acceptable economic cost. Problem of technological factors of high pressure die casting has been a subject of worldwide research (EU, US, Japan, etc.. The final performance properties of die castings are subjected to a large number of technological factors. The main technological factors of high pressure die casting are as follows: plunger pressing speed, specific (increase pressure, mold temperature as well as alloy temperature. The contribution discusses the impact of the plunger pressing speed and specific (increase pressure on the mechanical properties of the casting aluminum alloy.

Precision casting of Ti-15V-3Cr-3Al-3Sn alloy setting

OpenAIRE

Nan Hai; Liu Changkui; Huang Dong

2008-01-01

In this research, Ti-15V-3Cr-3Al-3Sn alloy ingots were prepared using ceramic mold and centrifugal casting. The Ti-15V-3Cr-3Al-3Sn setting casting, for aeronautic engine, with 1.5 mm in thickness was manufactured. The alloy melting process, precision casting process, and problems in casting application were discussed. Effects of Hot Isostatic Pressing and heat treatment on the mechanical properties and microstructure of the Ti-15V-3Cr-3Al-3Sn alloy were studied.

Filler metal alloy for welding cast nickel aluminide alloys

Science.gov (United States)

Santella, M.L.; Sikka, V.K.

1998-03-10

A filler metal alloy used as a filler for welding cast nickel aluminide alloys contains from about 15 to about 17 wt. % chromium, from about 4 to about 5 wt. % aluminum, equal to or less than about 1.5 wt. % molybdenum, from about 1 to about 4.5 wt. % zirconium, equal to or less than about 0.01 wt. % yttrium, equal to or less than about 0.01 wt. % boron and the balance nickel. The filler metal alloy is made by melting and casting techniques such as are melting the components of the filler metal alloy and cast in copper chill molds. 3 figs.

Friction Stir Processing of Cast Superalloys, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — This SBIR effort examines the feasibility of an innovative fabrication technology incorporating sand casting and friction stir processing (FSP) for producing...

Effect of technological parameters on formability of semi-solid rheological casting-forging 6061 alloy

Directory of Open Access Journals (Sweden)

Jianbo TAN

2016-02-01

Full Text Available The 6061 alloy cooling curve is determined by analysis software, and the 6061 semi-solid alloy is prepared by manual paddling process. The primary solid fraction is tested through prepared water quenched samples under different temperature. With H1F100 type servo press and cup type test mold, the forming of the 6061 semi-solid alloy rheological casting-forging is made. The influence of alloy temperature, forming pressure, upper mould temperature and holding time on the formability of 6061 alloy is researched. The results show that within the same set of mold completing casting and forging of the alloy is feasible. Along with the increase of the alloy temperature and the upper mould temperature, the formability of finished products becomes better. Under this experimentation, when the temperature of the semi-solid alloy is amongst 642 ℃ to 645 ℃ and the upper mould preheating temperature is amongst 200 ℃ to 300 ℃, casting defects such as cold insulation will form in the casting-forging sample of semi-solid 6061 alloy with the prolongation of holding time.

Journal of EEA, Vol. 30, 2013 SAND SINTERING PROBLEM ON ...

African Journals Online (AJOL)

dell

countries degree of roughness of the cast surface is determined by ... Coating reduces the casting surface adhering sand and chemical .... property in service and certain amount of zinc for compensation of its .... including pumps, pipes, taps and impellers .It is because they ... suitable for iron and steel melting. It should be ...

Fabrication of Hierarchically Micro- and Nano-structured Mold Surfaces Using Laser Ablation for Mass Production of Superhydrophobic Surfaces

Science.gov (United States)

Noh, Jiwhan; Lee, Jae-Hoon; Na, Suckjoo; Lim, Hyuneui; Jung, Dae-Hwan

2010-10-01

Many studies have examined the formation of surfaces with mixed patterns of micro- and nano-sized lotus leaves that have hydrophobic properties. In this study, micro- and nano-shapes such as lotus leaves were fabricated on a metal mold surface using laser ablation and ripple formation. A microstructure on the mold surface was replicated onto poly(dimethylsiloxane) (PDMS) using the polymer casting method to manufacture low-cost hydrophobic surfaces. A PDMS surface with micro- and nano-structures that were the inverse image of a lotus leaf showed hydrophobic characteristics (water contact angle: 157°). From these results, we deduced that portions of the microstructures were wet and that air gaps existed between the microstructures and the water drops. In this paper we suggest the possibility of the mass production of hydrophobic plastic surfaces and the development of a methodology for the hydrophobic texturing of various polymer surfaces, using the polymer casting method with laser-processed molds.

Friction Stir Processing of Cast Superalloys, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — This SBIR Phase I effort examines the feasibility of an innovative fabrication technology incorporating sand casting and friction stir processing (FSP) for producing...

Gases Emission From Surface Layers of Sand Moulds and Cores Stored Under the Humid Air Conditions

Directory of Open Access Journals (Sweden)

Kaźnica N.

2017-12-01

Full Text Available A large number of defects of castings made in sand moulds is caused by gases. There are several sources of gases: gases emitted from moulds, cores or protective coatings during pouring and casting solidification; water in moulding sands; moisture adsorbed from surroundings due to atmospheric conditions changes. In investigations of gas volumetric emissions of moulding sands amounts of gases emitted from moulding sand were determined - up to now - in dependence of the applied binders, sand grains, protective coatings or alloys used for moulds pouring. The results of investigating gas volumetric emissions of thin-walled sand cores poured with liquid metal are presented in the hereby paper. They correspond to the surface layer in the mould work part, which is decisive for the surface quality of the obtained castings. In addition, cores were stored under conditions of a high air humidity, where due to large differences in humidity, the moisture - from surroundings - was adsorbed into the surface layer of the sand mould. Due to that, it was possible to asses the influence of the adsorbed moisture on the gas volumetric emission from moulds and cores surface layers by means of the new method of investigating the gas emission kinetics from thin moulding sand layers heated by liquid metal. The results of investigations of kinetics of the gas emission from moulding sands with furan and alkyd resins as well as with hydrated sodium silicate (water glass are presented. Kinetics of gases emissions from these kinds of moulding sands poured with Al-Si alloy were compared.

Thermoluminescent dosimetric properties of Descalvado sand

International Nuclear Information System (INIS)

Teixeira, M.I.; Caldas, L.V.E.

2006-01-01

Sand samples proceeding from Descalvado, Sao Paulo, were studied with regard to their dosimetric properties using the thermoluminescence technique (TL) for high doses. These sand samples present steady physical and chemical characteristics to the end items, and they are used in the glass industry and for casting. The TL curves of the samples were obtained after an irradiation at the Gamma-Cell system ( 60 Co), of IPEN. The glow curves present two peaks at 80 C and 220 C approximately. Calibration curves were obtained for doses between 50 Gy and 5 kGy. The results indicate that the sand samples can be used for high-doses dosimetry in several areas of applications of ionizing radiation. (Author)

Thermoluminescent dosimetric properties of Descalvado sand

Energy Technology Data Exchange (ETDEWEB)

Teixeira, M.I.; Caldas, L.V.E

2006-07-01

Sand samples proceeding from Descalvado, Sao Paulo, were studied with regard to their dosimetric properties using the thermoluminescence technique (TL) for high doses. These sand samples present steady physical and chemical characteristics to the end items, and they are used in the glass industry and for casting. The TL curves of the samples were obtained after an irradiation at the Gamma-Cell system ({sup 60} Co), of IPEN. The glow curves present two peaks at 80 C and 220 C approximately. Calibration curves were obtained for doses between 50 Gy and 5 kGy. The results indicate that the sand samples can be used for high-doses dosimetry in several areas of applications of ionizing radiation. (Author)

INFLUENCE OF DIVIDING COVERINGS ON QUALITY OF CASTINGS AT MOLDING OF ALUMINUM ALLOYS UNDER PRESSURE

Directory of Open Access Journals (Sweden)

A. A. Pivovarchik

2014-01-01

Full Text Available The results of researches on influence of separating coverings on such properties of castings as corrosion resistance, roughness of cast surface, casting density are given in article.

Transferencia de calor en la colada continua de aceros. I parte. El molde

Directory of Open Access Journals (Sweden)

Cicutti, C.

1997-10-01

Full Text Available The continuous casting mold plays the important role of receiving the liquid steel and allowing an uniform and defect free solidified skin to be developed. In this work, the different heat transfer mechanisms which are present from the liquid steel to the mold cooling water are reviewed. The effect of operating variables on heat extraction and the relationship between global and distributed heat flux are also analyzed.

El molde de colada continua cumple la importante función de recibir el acero líquido y permitir que se desarrolle una capa solidificada uniforme y libre de defectos. En este trabajo se revisan los distintos mecanismos implicados en el proceso de transferencia de calor, desde el acero líquido hasta el agua de refrigeración del molde. Se analiza también el efecto de las distintas variables de funcionamiento en la extracción calórica producida y la relación entre el flujo global de calor y su distribución a lo largo del molde.

Manufacture of mold of polymeric composite water pipe reinforced charcoal

Science.gov (United States)

Zulfikar; Misdawati; Idris, M.; Nasution, F. K.; Harahap, U. N.; Simanjuntak, R. K.; Jufrizal; Pranoto, S.

2018-03-01

In general, household wastewater pipelines currently use thermoplastic pipes of Polyvinyl Chloride (PVC). This material is known to be not high heat resistant, contains hazardous chemicals (toxins), relatively inhospitable, and relatively more expensive. Therefore, researchers make innovations utilizing natural materials in the form of wood charcoal as the basic material of making the water pipe. Making this pipe requires a simple mold design that can be worked in the scale of household and intermediate industries. This research aims to produce water pipe mold with simple design, easy to do, and making time relatively short. Some considerations for molding materials are weight of mold, ease of raw material, strong, sturdy, and able to cast. Pipe molds are grouped into 4 (four) main parts, including: outer diameter pipe molding, pipe inside diameter, pipe holder, and pipe alignment control. Some materials have been tested as raw materials for outer diameter of pipes, such as wood, iron / steel, cement, and thermoset. The best results are obtained on thermoset material, where the process of disassembling is easier and the resulting mold weight is relatively lighter. For the inside diameter of the pipe is used stainless steel, because in addition to be resistant to chemical processes that occur, in this part of the mold must hold the press load due to shrinkage of raw materials of the pipe during the process of hardening (polymerization). Therefore, it needs high pressure resistant material and does not blend with the raw material of the pipe. The base of the mold is made of stainless steel material because it must be resistant to corrosion due to chemical processes. As for the adjustment of the pipe is made of ST 37 carbon steel, because its function is only as a regulator of the alignment of the pipe structure.

Influence of the section size and holding time on the graphite parameters of ductile iron production

Directory of Open Access Journals (Sweden)

S. Bockus

2009-01-01

Full Text Available This work was conducted to establish the conditions required to produce a desirable structure of the castings of various section sizes. This investigation was focused on the study of the influence of cooling rate or section size and holding time on graphite parameters of the ductile iron. Plates having thickness between 3 and 50mm were cast in sand molds using the same melt. The present investigation has shown that the section size of ductile iron castings and holding time had strong effect on the graphite parameters of the castings.

Fluid flow and heat transfer modeling for castings

International Nuclear Information System (INIS)

Domanus, H.M.; Liu, Y.Y.; Sha, W.T.

1986-01-01

Casting is fundamental to manufacturing of many types of equipment and products. Although casting is a very old technology that has been in existence for hundreds of years, it remains a highly empirical technology, and production of new castings requires an expensive and time-consuming trial-and-error approach. In recent years, mathematical modeling of casting has received increasing attention; however, a majority of the modeling work has been in the area of heat transfer and solidification. Very little work has been done in modeling fluid flow of the liquid melt. This paper presents a model of fluid flow coupled with heat transfer of a liquid melt for casting processes. The model to be described in this paper is an extension of the COMMIX code and is capable of handling castings with any shape, size, and material. A feature of this model is the ability to track the liquid/gas interface and liquid/solid interface. The flow of liquid melt through the sprue and runners and into the mold cavity is calculated as well as three-dimensional temperature and velocity distributions of the liquid melt throughout the casting process. 14 refs., 13 figs

Tribological and Wear Performance of Nanocomposite PVD Hard Coatings Deposited on Aluminum Die Casting Tool

Directory of Open Access Journals (Sweden)

Jose Mario Paiva

2018-02-01

Full Text Available In the aluminum die casting process, erosion, corrosion, soldering, and die sticking have a significant influence on tool life and product quality. A number of coatings such as TiN, CrN, and (Cr,AlN deposited by physical vapor deposition (PVD have been employed to act as protective coatings due to their high hardness and chemical stability. In this study, the wear performance of two nanocomposite AlTiN and AlCrN coatings with different structures were evaluated. These coatings were deposited on aluminum die casting mold tool substrates (AISI H13 hot work steel by PVD using pulsed cathodic arc evaporation, equipped with three lateral arc-rotating cathodes (LARC and one central rotating cathode (CERC. The research was performed in two stages: in the first stage, the outlined coatings were characterized regarding their chemical composition, morphology, and structure using glow discharge optical emission spectroscopy (GDOES, scanning electron microscopy (SEM, and X-ray diffraction (XRD, respectively. Surface morphology and mechanical properties were evaluated by atomic force microscopy (AFM and nanoindentation. The coating adhesion was studied using Mersedes test and scratch testing. During the second stage, industrial tests were carried out for coated die casting molds. In parallel, tribological tests were also performed in order to determine if a correlation between laboratory and industrial tests can be drawn. All of the results were compared with a benchmark monolayer AlCrN coating. The data obtained show that the best performance was achieved for the AlCrN/Si3N4 nanocomposite coating that displays an optimum combination of hardness, adhesion, soldering behavior, oxidation resistance, and stress state. These characteristics are essential for improving the die mold service life. Therefore, this coating emerges as a novelty to be used to protect aluminum die casting molds.

Tribological and Wear Performance of Nanocomposite PVD Hard Coatings Deposited on Aluminum Die Casting Tool.

Science.gov (United States)

Paiva, Jose Mario; Fox-Rabinovich, German; Locks Junior, Edinei; Stolf, Pietro; Seid Ahmed, Yassmin; Matos Martins, Marcelo; Bork, Carlos; Veldhuis, Stephen

2018-02-28

In the aluminum die casting process, erosion, corrosion, soldering, and die sticking have a significant influence on tool life and product quality. A number of coatings such as TiN, CrN, and (Cr,Al)N deposited by physical vapor deposition (PVD) have been employed to act as protective coatings due to their high hardness and chemical stability. In this study, the wear performance of two nanocomposite AlTiN and AlCrN coatings with different structures were evaluated. These coatings were deposited on aluminum die casting mold tool substrates (AISI H13 hot work steel) by PVD using pulsed cathodic arc evaporation, equipped with three lateral arc-rotating cathodes (LARC) and one central rotating cathode (CERC). The research was performed in two stages: in the first stage, the outlined coatings were characterized regarding their chemical composition, morphology, and structure using glow discharge optical emission spectroscopy (GDOES), scanning electron microscopy (SEM), and X-ray diffraction (XRD), respectively. Surface morphology and mechanical properties were evaluated by atomic force microscopy (AFM) and nanoindentation. The coating adhesion was studied using Mersedes test and scratch testing. During the second stage, industrial tests were carried out for coated die casting molds. In parallel, tribological tests were also performed in order to determine if a correlation between laboratory and industrial tests can be drawn. All of the results were compared with a benchmark monolayer AlCrN coating. The data obtained show that the best performance was achieved for the AlCrN/Si₃N₄ nanocomposite coating that displays an optimum combination of hardness, adhesion, soldering behavior, oxidation resistance, and stress state. These characteristics are essential for improving the die mold service life. Therefore, this coating emerges as a novelty to be used to protect aluminum die casting molds.

Effectiveness of SCADA Systems in Control of Green Sands Properties

Directory of Open Access Journals (Sweden)

Ignaszak Z.

2016-03-01

Full Text Available The paper undertakes an important topic of evaluation of effectiveness of SCADA (Supervisory Control and Data Acquisition systems, used for monitoring and control of selected processing parameters of classic green sands used in foundry. Main focus was put on process studies of properties of so-called 1st generation molding sands in the respect of their preparation process. Possible methods of control of this processing are presented, with consideration of application of fresh raw materials, return sand (regenerate and water. The studies conducted in one of European foundries were aimed at pointing out how much application of new, automated plant of sand processing incorporating the SCADA systems allows stabilizing results of measurement of selected sand parameters after its mixing. The studies concerned two comparative periods of time, before an implementation of the automated devices for green sands processing (ASMS - Automatic Sand Measurement System and MCM – Main Control Module and after the implementation. Results of measurement of selected sand properties after implementation of the ASMS were also evaluated and compared with testing studies conducted periodically in laboratory.

Effect of Y additions on the solidification behavior of a copper mold cast CuZrAl alloy with high oxygen content

International Nuclear Information System (INIS)

Coury, F.G.; Batalha, W.; Botta, W.J.; Bolfarini, C.; Kiminami, C.S.

2014-01-01

Bulk glassy samples of the CuAlZr system were produced by copper mold casting in the form of wedges with different amounts of yttrium (0 , 0.3 and 2 at%) , the processing conditions led to high oxygen contents on the samples (1000ppm). A reportedly good glass-former composition was chosen as the base alloy, it’s nominal composition is Cu47Zr45Al8. This study aimed to understand the influence of oxygen and yttrium in the solidification of these alloys. The samples were analyzed by scanning and transmission electron microscopy, differential scanning calorimetry and X-Ray diffraction. The sequence of formation of crystalline phases in these alloys was determined as a function of the different cooling rates inherent in the process. It was observed that the formation of CuZr2 phase was inhibited in samples with Y allowing the production of a fully glassy 8mm. (author)

The Suitability Of Local Quartz Sand In The Production Of Bath Crucibles.

Directory of Open Access Journals (Sweden)

C. O. Okpanachi

2017-03-01

Full Text Available The suitability of local quartz sand in the production of bath crucibles is a study that was carried out in order to impart overall strength on bath crucibles hence reduce breakages during fettling. Therefore this research constitutes a study to enhance the efficiency of production of bath crucibles by addition of quartz sand in slip preparation. The steps taken in the beneficiation of quartz sand for the production of bath crucibles are comminution which entails crushing and milling classification washing liquid dispersion sizing and reduction of iron content by magnetic separation. The slip contains materials like plastic clay feldspar kaolin talc sodium silicate water quartz sand etc. These were all milled in the ball mill for slip production casting and fettling glazing and sintering to get final bath crucibles as the end products. Quartz sand is used in a variety of products essentially as raw material for the foundry casting and glass industries and also in chemicals water filtration and ceramics the heat resistance nature of quartz sand makes it an excellent refractory substance for these industrial processes. Slip can be prepared for production of bath crucibles without the inclusion of quartz sand however the addition of quartz sand is needed to improve the mechanical performance of the slip in the production of bath crucibles.

Comparison in processing routes by copper mold casting injection and suction in the Cu46Zr42Al7Y5 vitreous alloy

International Nuclear Information System (INIS)

Batalha, W.; Aliaga, L.C.R.; Bolfarini, C.; Botta, W.J.; Kiminami, C.S.

2014-01-01

To expand the application of glassy metals, the development of processing routes and compositions that allow the production of parts with dimensions of millimeters or even centimeters, is very important. The present work aims the contribution to the technological development of processing routes for the production of Cu-based bulk metallic glasses. Wedge-shaped samples of Cu 46 Zr 42 Al 7 Y 5 (atom percent) chemical composition were processed using copper mold casting by suction and injection. Characterization was made combining scanning electron microscopy, x-ray diffraction and differential scanning calorimetry. The critical amorphous thickness obtained by those two different routes was carefully observed. The suction route allow obtaining the best results with critical amorphous thickness about 8 mm. This result was analyzed considering the different extrinsic parameters to the glass forming ability of the alloy. (author)

Systems and Methods for Fabricating Structures Including Metallic Glass-Based Materials Using Low Pressure Casting

Science.gov (United States)

Hofmann, Douglas C. (Inventor); Kennett, Andrew (Inventor)

2018-01-01

Systems and methods to fabricate objects including metallic glass-based materials using low-pressure casting techniques are described. In one embodiment, a method of fabricating an object that includes a metallic glass-based material includes: introducing molten alloy into a mold cavity defined by a mold using a low enough pressure such that the molten alloy does not conform to features of the mold cavity that are smaller than 100 microns; and cooling the molten alloy such that it solidifies, the solid including a metallic glass-based material.

Elimination or Minimization of Oscillation Marks: A Path To Improved Cast Surface Quality

Energy Technology Data Exchange (ETDEWEB)

Dr. Alan W. Cramb

2007-12-17

Oscillation marks are the most recognizable feature of continuous casting and can be related to the subsurface defects that can be found on product rolled from continuous cast slabs. The purpose of this work was to develop strategies that can be used on industrial continuous casters to reduce oscillation mark depth and, in particular, to minimize the formation of hook type defects that are prevalent on ultra low carbon grades. The major focus of the work was on developing a technique to allow heat transfer in the meniscus region of the continuous caster to be measured and the effect of mold slag chemistry and chrystallization to be documented. A new experimental technique was developed that allowed the effect of mold flux chemistry and chrystallization on the radiation heat transfer rate to be measured dynamically.

Using a micro-molding process to fabricate polymeric wavelength filters

Science.gov (United States)

Chuang, Wei-Ching; Lee, An-Chen; Ho, Chi-Ting

2008-08-01

A procedure for fabricating a high aspect ratio periodic structure on a UV polymer at submicron order using holographic interferometry and molding processes is described. First, holographic interferometry using a He-Cd (325 nm) laser was used to create the master of the periodic line structure on an i-line sub-micron positive photoresist film. A 20 nm nickel thin film was then sputtered on the photoresist. The final line pattern on a UV polymer was obtained from casting against the master mold. Finally, a SU8 polymer was spun on the polymer grating to form a planar waveguide or a channel waveguide. The measurement results show that the waveguide length could be reduced for the waveguide having gratings with a high aspect ratio.

Cast Ductile Iron 155mm M804 Bodies

Science.gov (United States)

1990-07-12

for the final delivery. The balance of the parts were returned to Wagner Castings for analysis, scrap, or de-militarization. The radiographic...as possible to avoid pre-cure. Mixing/ mulling time should be consistent with the system " worklife " or poor composite properties will result. Tensile...Burn-in on castings is caused by poor sand density, poor mixing, out of balance mix or improper drying of the wash. Long set times are an indication

The potential of centrifugal casting for the production of near net shape uranium parts

International Nuclear Information System (INIS)

Robertson, E.

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

Effect of reinforcement amount, mold temperature, superheat, and mold thickness on fluidity of in-situ Al-Mg2Si composites

Directory of Open Access Journals (Sweden)

Reza Vatankhah Barenji

2018-01-01

Full Text Available In the present study, the effects of mold temperature, superheat, mold thickness, and Mg2Si amount on the fluidity of the Al-Mg2Si as-cast in-situ composites were investigated using the mathematical models. Composites with different amounts of Mg2Si were fabricated, and the fluidity and microstructure of each were then analyzed. For this purpose, the experiments were designed using a central composite rotatable design, and the relationship between parameters and fluidity were developed using the response surface method. In addition, optical and scanning electron microscopes were used for microstructural observation. The ANOVA shows that the mathematical models can predict the fluidity accurately. The results show that by increasing the mold temperature from 25 °C to 200 °C, superheat from 50 °C to 250 °C, and thickness from 3 mm to 12 mm, the fluidity of the composites decreases, where the mold thickness is more effective than other factors. In addition, the higher amounts of Mg2Si in the range from 15wt.% to 25wt.% lead to the lower fluidity of the composites. For example, when the mold temperature, superheat, and thickness are respectively 100 °C, 150 °C, and 7 mm, the fluidity length is changed in the range of 11.9 cm to 15.3 cm. By increasing the amount of Mg2Si, the morphology of the primary Mg2Si becomes irregular and the size of primary Mg2Si is increased. Moreover, the change of solidification mode from skin to pasty mode is the most noticeable microstructural effect on the fluidity.

Experimental analysis of flow of ductile cast iron in stream lined gating systems

DEFF Research Database (Denmark)

Skov-Hansen, Søren Peter; Tiedje, Niels Skat

2008-01-01

Streamlined gating systems have been developed for production of high integrity ductile cast iron parts. Flow of ductile cast iron in streamlined gating systems was studied in glass fronted sand moulds where flow in the gating system and casting was recorded by a digital video camera. These results...... show how the quality of pouring, design of ingates, design of bends and flow over cores influence melt flow and act to determine the quality of the castings....

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

International Nuclear Information System (INIS)

Hekmat-Ardakan, A.; Elgallad, E.M.; Ajersch, F.; Chen, X.-G.

2012-01-01

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 2 CuMg, Al 2 Cu and Al 2 CuLi intermetallic phases formed at the aluminum dendrite boundaries, which can be completely dissolved in the α-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 θ′ (Al 2 Cu) and T1 (Al 2 CuLi) precipitates. However, the non-uniform distribution of T1 precipitates together with the large size and low density indicate that the role of θ′ 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.

Numerical and Experimental Analysis on the Cavity Formation and Shrinkage for Investment Cast Alloy 738 4 mm-Thick Rectangular Tube

International Nuclear Information System (INIS)

Park, Myeong-Il; Choi, Yoon Suk; Yoo, Jae-Hyun; Park, Sang-Hu; Kim, Kyeong-Min; Lee, Yeong-Chul; Lee, Jung-Seok; Lee, Jae-Hyun

2017-01-01

Investment casting for the thin (4 mm thick) rectangular tube (40 mm wide, 80 mm high and 200 mm long) was carried out numerically and experimentally for Alloy 738, which is a precipitation-hardened Ni-base superalloy. Two types of rectangular tubes, one with a regular array (10 mm by 10 mm square array) of protruded rods (3 mm in diameter and 3mm in height) embedded on the outer surface and the other with just smooth surface, were investment-cast at the same time through the side feeding mold design. The investment casting simulation predicted the presence of cavities, particularly in the area away from the gate for both types of rectangular tubes. In particular, for the rectangular tube with embedded protruded rods cavities were found mainly in the areas between the protruded rods. This simulation result was qualitatively consistent with the experimental observation from the X-ray analysis. Also, both prediction and experiment showed that the dimensional shrinkage (particularly in the longitudinal direction) of the investment-cast rectangular tube is reduced by having protruded rods embedded on the outer surface. Additional numerical attempts were made to check how the amount of cavities and dimensional shrinkage change by varying the preheating temperature and the thickness of the mold. The results predicted that the amount of cavities and the dimensional shrinkage are significantly reduced by increasing the preheating temperature of the mold by 200 ℃. However, an increase in mold thickness from 10 mm to 12 mm showed almost no difference in cavity population and a slight decrease in dimensional shrinkage.

Numerical and Experimental Analysis on the Cavity Formation and Shrinkage for Investment Cast Alloy 738 4 mm-Thick Rectangular Tube

Energy Technology Data Exchange (ETDEWEB)

Park, Myeong-Il; Choi, Yoon Suk; Yoo, Jae-Hyun; Park, Sang-Hu [Pusan National University, Busan (Korea, Republic of); Kim, Kyeong-Min; Lee, Yeong-Chul [Sung Il Turbine Co., Ltd., Busan (Korea, Republic of); Lee, Jung-Seok; Lee, Jae-Hyun [Changwon National University, Changwon (Korea, Republic of)

2017-02-15

Investment casting for the thin (4 mm thick) rectangular tube (40 mm wide, 80 mm high and 200 mm long) was carried out numerically and experimentally for Alloy 738, which is a precipitation-hardened Ni-base superalloy. Two types of rectangular tubes, one with a regular array (10 mm by 10 mm square array) of protruded rods (3 mm in diameter and 3mm in height) embedded on the outer surface and the other with just smooth surface, were investment-cast at the same time through the side feeding mold design. The investment casting simulation predicted the presence of cavities, particularly in the area away from the gate for both types of rectangular tubes. In particular, for the rectangular tube with embedded protruded rods cavities were found mainly in the areas between the protruded rods. This simulation result was qualitatively consistent with the experimental observation from the X-ray analysis. Also, both prediction and experiment showed that the dimensional shrinkage (particularly in the longitudinal direction) of the investment-cast rectangular tube is reduced by having protruded rods embedded on the outer surface. Additional numerical attempts were made to check how the amount of cavities and dimensional shrinkage change by varying the preheating temperature and the thickness of the mold. The results predicted that the amount of cavities and the dimensional shrinkage are significantly reduced by increasing the preheating temperature of the mold by 200 ℃. However, an increase in mold thickness from 10 mm to 12 mm showed almost no difference in cavity population and a slight decrease in dimensional shrinkage.

Used Furan Sand Reclamation in REGMAS Vibratory Unit

Directory of Open Access Journals (Sweden)

Dańko J.

2015-09-01

Full Text Available The paper, especially dealt with problems of reclamation of used furan sand, carried out in new, vibratory sand reclamation unit REGMAS developed by researches from AGH-University of Science and Technology, Faculty of Foundry Engineering in Cracow (Poland. Functional characteristics of reclamation unit as well as the results of reclamation of used sand with furfuryl resin are discussed in the paper. The quality of reclaim was tested by means of the LOI and pH value, dust content in the reclaim and at least by the the quality of the castings produced in moulds prepared with the use of reclaimed matrix.

APPLICATION OF POLYSTYRENE FOAM CORE FUSIBLE PATTERNS IN PRODUCTION OF GAS TURBINES’ CAST PARTS

Directory of Open Access Journals (Sweden)

O. I. Shinsky

2016-01-01

Full Text Available The task of replacing the LVM dissolves polystyrene molding on models is at the present time, technologically, economically and environmentally promising from the point of view of industrial applications for gas turbine plants in Ukraine. The authors proposed and tested manufacturing process of casting ceramic molds way to remove the polystyrene model of the dissolution of her organic solvents. Kinetic parameters of the process of dissolving and removing patterns of degradation products the polystyrene in the group of solvents depending on the type and amount of polystyrene were identified. The absence of surface defects of castings, reduction of roughness, increased their accuracy class in comparison to accepted technological regulations of the process of production, which reduced the cost of machined parts and increased utilization of expensive heat-resistant alloys were produced.

A non-contact 3D method to characterize the surface roughness of castings

DEFF Research Database (Denmark)

Nwaogu, Ugochukwu Chibuzoh; Tiedje, Niels Skat; Hansen, Hans Nørgaard

2013-01-01

that the surface quality of the standard comparators was successfully evaluated and it was established that the areal parameters are the most informative for cast components. The results from the surface comparators were compared with the results from a stylus instrument. Sand cast components were also evaluated...

Fabrication of Ti-0.48Al Alloy by Centrifugal Casting.

Science.gov (United States)

Park, Jong Bum; Lee, Jung-Il; Ryu, Jeong Ho

2018-09-01

Many of the unique properties of TiAl alloys that make are attractive for use in high-temperature structural applications also make it challenging to process them into useful products. Cast TiAl is rapidly nearing commercialization, particularly in the vehicle industry, owing to its low production cost. In this study, the centrifugal casting of a TiAl (Ti-48%Al, mole fraction) turbocharger was simulated and an experimental casting was created in vacuum using an induction melting furnace coupled to a ceramic composite mold. Numerical simulation results agreed with the experiment. The crystal structure, microstructure, and chemical composition of the TiAl prepared by centrifugal casting were studied by X-ray diffractometry, optical microscopy, field emission scanning electron microscopy (FE-SEM) and energy dispersive spectroscopy (EDS). FE-SEM and EDS examinations of the TiAl casting revealed that the thickness of the oxide layer (α-case) was typically less than 35 μm.

Preliminary study on tensile properties and fractography of the recycled aluminum cast product

International Nuclear Information System (INIS)

Hishamuddin Hussain; Mohd Harun; Hafizal Yazid; Shaiful Rizam Shamsudin; Zaiton Selamat; Mohd Shariff Sattar

2004-01-01

Among many mechanical properties of materials, tensile properties are probably the most frequently considered, evaluated, and referred by the industry. This paper presents the result of preliminary study regarding the tensile properties and fractography of the recycled aluminum cast product. For this purpose, three sets of specimen were prepared for tensile testing by using permanent mold casting technique. The cast products are in durable shaped tensile specimens with the gauge length of 50mm. The tensile testing was conducted in accordance with BS EN 10002-1 and ISO 6892 standards. Fracture surface analysis was also conducted to understand materials behaviour. (Author)

Suitability of a South African silica sand for three-dimensional printing of foundry moulds and cores

Directory of Open Access Journals (Sweden)

Nyembwe, Kasongo

2016-11-01

Full Text Available Applications of three-dimensional printing (3DP to metal casting include, among other things, the direct manufacturing of foundry moulds and cores in refractory materials such as silica sand. The main properties of silica sand that are essentially related to the traditional moulding and core-making processes are: size distribution, clay content, pH, acid demand, and refractoriness. The silica sand used for 3DP must also be appropriately selected for the layer-based manufacturing process involved in 3DP. Properties such as grain size distribution, grain surface morphology, angularity, flowability, and recoating abilities have a particular importance when determining sand suitability. Because of these extra requirements, only a limited range of available foundry silica sands can be used for 3DP processes. The latter situation explains the scarcity and high cost of suitable silica sands, thus contributing to the relatively high operational costs of the 3DP processes for the production of sand moulds and cores. This research paper investigates the suitability of a locally-available silica sand for use in a Voxeljet VX1000 3DP machine. The local silica sand was assessed and compared with an imported silica sand recommended by the manufacturer of 3DP equipment in terms of foundry characteristics and recoating behaviour. The study shows that, despite the differences between the characteristics of the two silica sands, the local sand could be considered a suitable alternative to imported sand for rapid sand casting applications.

On Degradation of Cast Iron Surface-Protective Paint Coat Joint

Directory of Open Access Journals (Sweden)

Tupaj M.

2016-09-01

Full Text Available The paper is a presentation of a study on issues concerning degradation of protective paint coat having an adverse impact on aesthetic qualities of thin-walled cast-iron castings fabricated in furan resin sand. Microscopic examination and microanalyses of chemistry indicated that under the coat of paint covering the surface of a thin-walled casting, layers of oxides could be found presence of which can be most probably attributed to careless cleaning of the casting surface before the paint application process, as well as corrosion pits evidencing existence of damp residues under the paint layers contributing to creation of corrosion micro-cells

Carbides in Nodular Cast Iron with Cr and Mo

Directory of Open Access Journals (Sweden)

S. Pietrowski

2007-07-01

Full Text Available In these paper results of elements microsegregation in carbidic nodular cast iron have been presented. A cooling rate in the centre of the cross-section and on the surface of casting and change of moulding sand temperature during casting crystallization and its self-cooling have been investigated. TDA curves have been registered. The linear distribution of elements concentration in an eutectic grain, primary and secondary carbides have been made. It was found, that there are two kinds of carbides: Cr and Mo enriched. A probable composition of primary and secondary carbides have been presented.

EXPERIMENTAL ANALYSIS AND ISHIKAWA DIAGRAM FOR BURN ON EFFECT ON MANGANESE SILICON ALLOY MEDIUM CARBON STEEL SHAFT

Directory of Open Access Journals (Sweden)

AsmamawTegegne

2013-12-01

Full Text Available Burn on/metal penetration is one of the surface defects of metal castings in general and steel castings in particular. A research on the effect of burn on the six ton medium carbon steel shaft for making a roller of cold rolled steel sheet produced at one of the metals industry was carried out. The shaft was cast using sand casting by pouring through riser/feeding head step by step (with time interval of pouring. As it was required to use foam casting method for better surface finish and dimensional accuracy of the cast, the pattern was prepared from polystyrene and embedded by silica sand. Physical observations, photographic analysis, visual inspection, measurement of depth of penetration and fish bone diagram were used as method of results analysis. The shaft produced has strongly affected by sand sintering (burn on/metal penetration. Many reasons may be the case for these defects, however analysis results showed that the use of poorly designed gating system led to turbulence flow, uncontrollable high temperature fused the silica sand and liquid polystyrene penetrated the poorly reclaimed and rammed sand mold as a result of which eroded sand has penetrated the liquid metal deeply and reacted with it, consequently after solidification and finishing the required 240mm diameter of the shaft has reduced un evenly to 133mm minimum and 229mm maximum mm that end in the rejection of the shaft from the product since it is below the required standard for the designed application. In addition, it was not possible to remove the adhered sand by grinding. Thus burn on is included in mechanical type burn on.

Casting Simulation of an Austrian Bronze Age Sword Hilt

Science.gov (United States)

Pola, Annalisa; Mödlinger, Marianne; Piccardo, Paolo; Montesano, Lorenzo

2015-07-01

Bronze Age swords with a metal hilt can be considered the peak of Bronze Age casting technologies. To reconstruct the casting techniques used more than 3000 years ago, a metal hilted sword of the Schalenknauf type from Lower Austria was studied with the aid of macroscopic analyses and simulation of mold filling and casting solidification. A three-dimensional model of the hilt was created based on optical scanner measurements performed on a hilt recently discovered during archaeological excavations. Three different configurations of the gating system were considered, two on the pommel disk and one on the knob, and the effect of its location on the formation of casting defects was investigated. Three-dimensional computed tomography was used to detect internal defects, such as gas and shrinkage porosity, which were then compared with those calculated by simulation. The best match between actual and predicted hilt quality demonstrated the location of the gating system, which turned out to be on the pommel disk.

LCD OF AIR INTAKE MANIFOLDS PHASE 2: FORD F250 AIR INTAKE MANIFOLD

Science.gov (United States)

The life cycle design methodology was applied to the design analysis of three alternatives for the lower plehum of the air intake manifold for us with a 5.4L F-250 truck engine: a sand cast aluminum, a lost core molded nylon composite, and a vibration welded nylon composite. The ...

Influence of the reclamation method of spent moulding sands on the possibility of creating favourable conditions for gases flow in a mould

Directory of Open Access Journals (Sweden)

Łucarz M.

2017-03-01

Full Text Available The results of investigations concerning the influence of the applied sand matrix (fresh sand, reclaim on the properties of moulding sands used for production of large dimensional castings (ingot moulds, ladles, are presented in the hereby paper. The performed investigations were aimed at determining the influence of various reclamation methods of spent moulding sands on the quality of the obtained reclaimed material. Moulding sands were prepared on the fresh quartz matrix as well as on sand matrices obtained after various reclamation methods. The selected moulding sand parameters were tested (strength, permeability, grindability, ignition losses, pH reactions. It can be stated, on the basis of the performed investigations, that the kind of the applied moulding sand matrix is of an essential meaning from the point of view of creating conditions minimising formation of large amounts of gases and their directional migration in a casting mould.

Low Loss Advanced Metallic Fuel Casting Evaluation

International Nuclear Information System (INIS)

Kim, Kihwan; Ko, Youngmo; Kim, Jonghwan; Song, Hoon; Lee Chanbock

2014-01-01

The fabrication process for SFR fuel is composed of fuel slug casting, loading and fabrication of the fuel rods, and the fabrication of the final fuel assemblies. Fuel slug casting is the dominant source of fuel losses and recycles streams in the fabrication process. Recycle streams include fuel slug reworks, returned scraps, and fuel casting heels, which are a special concern in the counter gravity injection casting process because of the large masses involved. Large recycle and waste streams result in lowering the productivity and the economic efficiency of fuel production. To increase efficiency the fuel losses in the furnace chamber, crucible, and the mold, after casting a considerable amount of fuel alloy in the casting furnace, will be quantitatively evaluated. After evaluation the losses will be identified and minimized. It is expected that this study will contribute to the minimization of fuel losses and the wastes streams in the fabrication process of the fuel slugs. Also through this study the technical readiness level of the metallic fuel fabrication process will be further enhanced. In this study, U-Zr alloy system fuel slugs were fabricated by a gravity casting method. Metallic fuel slugs were successfully fabricated with 19 slugs/batch with diameter of 5mm and length of 300mm. Fuel losses was quantitatively evaluated in casting process for the fuel slugs. Fuel losses of the fuel slugs were so low, 0.1∼1.0%. Injection casting experiments have been performed to reduce the fuel loss and improve the casting method. U-Zr fuel slug having φ5.4-L250mm was soundly fabricated with 0.1% in fuel loss. The fuel losses could be minimized to 0.1%, which showed that casting technology of fuel slugs can be a feasible approach to reach the goal of the fuel losses of 0.1% or less in commercial scale

Metallic Reinforcement of Direct Squeeze Die Casting Aluminum Alloys for Improved Strength and Fracture Resistance

Energy Technology Data Exchange (ETDEWEB)

D. Schwam: J.F. Wallace: Y. Zhu: J.W. Ki

2004-10-01

The utilization of aluminum die casting as enclosures where internal equipment is rotating inside of the casting and could fracture requires a strong housing to restrain the fractured parts. A typical example would be a supercharger. In case of a failure, unless adequately contained, fractured parts could injure people operating the equipment. A number of potential reinforcement materials were investigated. The initial work was conducted in sand molds to create experimental conditions that promote prolonged contact of the reinforcing material with molten aluminum. Bonding of Aluminum bronze, Cast iron, and Ni-resist inserts with various electroplated coatings and surface treatments were analyzed. Also toughening of A354 aluminum cast alloy by steel and stainless steel wire mesh with various conditions was analyzed. A practical approach to reinforcement of die cast aluminum components is to use a reinforcing steel preform. Such performs can be fabricated from steel wire mesh or perforated metal sheet by stamping or deep drawing. A hemispherical, dome shaped casting was selected in this investigation. A deep drawing die was used to fabricate the reinforcing performs. The tendency of aluminum cast enclosures to fracture could be significantly reduced by installing a wire mesh of austenitic stainless steel or a punched austenitic stainless steel sheet within the casting. The use of reinforcements made of austenitic stainless steel wire mesh or punched austenitic stainless steel sheet provided marked improvement in reducing the fragmentation of the casting. The best strengthening was obtained with austenitic stainless steel wire and with a punched stainless steel sheet without annealing this material. Somewhat lower results were obtained with the annealed punched stainless steel sheet. When the annealed 1020 steel wire mesh was used, the results were only slightly improved because of the lower mechanical properties of this unalloyed steel. The lowest results were

Dome style heavy wall steel casting manufactured by metallic core mould system

International Nuclear Information System (INIS)

Yamamoto, Shiro; Saeki, Keiji; Hirose, Yutaka; Takebayashi, Kazunari; Kawasaki, Masatoshi

1986-01-01

Semi-spherical thick walled steel castings are one of the main products of Nippon Chutanko K.K., but there have been the problems of internal defects peculiar to large thick walled steel castings, and the various improvements have been carried out so far for the manufacturing method, but still some of those remains. Based on the anxiety about the reliability of large steel castings, the conversion to forging has been studied. For the purpose of thoroughly improving the internal quality of thick walled steel castings to compete with forgings, on the basis of the operating experience of chills, the development of the casting techniques changing cores completely to metallic cores has been advanced. After the preliminary experiment using models, a semi-spherical thick walled steel casting mentioned before was manufactured by this metallic core casting method for trial, and the detailed investigation was carried out. As the result, the excellent internal quality was confirmed, accordingly at present, the production is made by this method. The form, dimensions and specification of the semi-spherical thick walled steel castings, the conventional casting plan, the metallic core casting plan, the design of metallic cores, molding and casting, and the examination of the castings made for trial are reported. (Kako, I.)

A coupled analysis of fluid flow, heat transfer and deformation behavior of solidifying shell in continuously cast beam blank

Energy Technology Data Exchange (ETDEWEB)

Lee, Jung Eui; Yeo, Tae Jung; Oh, Kyu Hwan; Yoon, Jong Kyu [School of Materials Science and Engineering, Seoul Nat` l Univ., Seoul (Korea, Republic of); Han, Heung Nam [Oxford Center for Advanced Materials and Composites, Department of Materials, Univ. of Oxford (United Kingdom)

1998-12-31

A mathematical model for a coupled analysis of fluid flow, heat transfer and deformation behavior in the continuously cast beam blank has been developed. The fluid flow, heat transfer and solidification in the mold region were analyzed with 3-dimensional finite difference method (FDM) based on control volume method. A body fitted coordinate system was introduced for the complex geometry of the beam blank. The effects of turbulence and natural convection of molten steel were taken into account in determining the fluid flow in the strand. The thermo-elasto-plastic deformation behavior in the cast strand and the formation of air gap between the solidifying shell and the mold were analyzed by the finite element method (FEM) using the 2-dimensional slice temperature profile calculated by the FDM. The heat flow between the strand and the mold was evaluated by the coupled analysis between the fluid flow-heat transfer analysis and the thermo-elasto-plastic stress analysis. In order to determine the solid fraction in the mushy zone, the microsegregation of solute element was assessed. The effects of fluid flow on the heat transfer, the solidification of steel and the distribution of shell thickness during the casting of the beam blank were simulated. The deformation behavior of the solidifying shell and the possibility of cracking of the strand were also investigated. The recirculating flows were developed in the regions of the web and the flange tip. The impinging of the inlet flow from the nozzle retarded the growing of solidifying shell in the regions of the fillet and the flange. The air gap between the strand and the mold was formed near the region of the corner of the flange tip. At the initial stage of casting, the probability of the surface cracking was high in the regions of the fillet and the flange tip. After the middle stage of casting, the internal cracking was predicted in the regions of the flange tip, and between the fillet and the flange tip. (author) 38

A coupled analysis of fluid flow, heat transfer and deformation behavior of solidifying shell in continuously cast beam blank

Energy Technology Data Exchange (ETDEWEB)

Lee, Jung Eui; Yeo, Tae Jung; Oh, Kyu Hwan; Yoon, Jong Kyu [School of Materials Science and Engineering, Seoul Nat`l Univ., Seoul (Korea, Republic of); Han, Heung Nam [Oxford Center for Advanced Materials and Composites, Department of Materials, Univ. of Oxford (United Kingdom)

1997-12-31

A mathematical model for a coupled analysis of fluid flow, heat transfer and deformation behavior in the continuously cast beam blank has been developed. The fluid flow, heat transfer and solidification in the mold region were analyzed with 3-dimensional finite difference method (FDM) based on control volume method. A body fitted coordinate system was introduced for the complex geometry of the beam blank. The effects of turbulence and natural convection of molten steel were taken into account in determining the fluid flow in the strand. The thermo-elasto-plastic deformation behavior in the cast strand and the formation of air gap between the solidifying shell and the mold were analyzed by the finite element method (FEM) using the 2-dimensional slice temperature profile calculated by the FDM. The heat flow between the strand and the mold was evaluated by the coupled analysis between the fluid flow-heat transfer analysis and the thermo-elasto-plastic stress analysis. In order to determine the solid fraction in the mushy zone, the microsegregation of solute element was assessed. The effects of fluid flow on the heat transfer, the solidification of steel and the distribution of shell thickness during the casting of the beam blank were simulated. The deformation behavior of the solidifying shell and the possibility of cracking of the strand were also investigated. The recirculating flows were developed in the regions of the web and the flange tip. The impinging of the inlet flow from the nozzle retarded the growing of solidifying shell in the regions of the fillet and the flange. The air gap between the strand and the mold was formed near the region of the corner of the flange tip. At the initial stage of casting, the probability of the surface cracking was high in the regions of the fillet and the flange tip. After the middle stage of casting, the internal cracking was predicted in the regions of the flange tip, and between the fillet and the flange tip. (author) 38

Dynamic of taking out molding parts at injection molding

Directory of Open Access Journals (Sweden)

E. Ragan

2012-10-01

Full Text Available Most plastic parts used in automobile production are manufactured by injection molding. Their quality depends also on taking out molding and on the manipulators for it. Task of this contribution is to theoretically describe a transport of molding at taking out after injection molding in relation on its regulation. The following quantities are derived at it: the transition characteristic of the taking out system, the blocking diagram of taking out molding regulation, the amplitude and phase characteristic and the transition characteristic of action quantity at taking out molding regulation.

Finite volume modeling of the solidification of an axial steel cast impeller

Directory of Open Access Journals (Sweden)

M. Copur

2014-04-01

Full Text Available In the foundry industry, obtaining the solidification contours in cast geometries are extremely important to know the last location(s to solidify in order to define the correct feeding path and the number of risers. This paper presents three-dimensional simulation of transient conduction heat transfer within an axial impeller, made of AISI 1016 steel, poured and solidified in chemically bonded mold and core medium, by using FVM technique and ANSYS CFX. Specific heat, density and thermal conductivity of AISI 1016 steel, mold and Core materials are considered as functions of temperatures. In this transient thermal analysis, the convection heat transfer phenomenon is also considered at the outer surfaces of the mold. In order to shorten the run-time, the nonlinear transient analysis has been made for 600/3600 segment of the impeller, core and mold. The solidification contours of the impeller as well as isothermal lines in core and mold have been obtained in 3-D. The cooling curves of diff erent points are also shown in the result section.

Grindability of cast Ti-Hf alloys.

Science.gov (United States)

Kikuchi, Masafumi; Takahashi, Masatoshi; Sato, Hideki; Okuno, Osamu; Nunn, Martha E; Okabe, Toru

2006-04-01

As part of our systematic studies characterizing the properties of titanium alloys, we investigated the grindability of a series of cast Ti-Hf alloys. Alloy buttons with hafnium concentrations up to 40 mass% were made using an argon-arc melting furnace. Each button was cast into a magnesia-based mold using a dental titanium casting machine; three specimens were made for each metal. Prior to testing, the hardened surface layer was removed. The specimens were ground at five different speeds for 1 min at 0.98 N using a carborundum wheel on an electric dental handpiece. Grindability was evaluated as the volume of metal removed per minute (grinding rate) and the volume ratio of metal removed compared to the wheel material lost (grinding ratio). The data were analyzed using ANOVA. A trend of increasing grindability was found with increasing amounts of hafnium, although there was no statistical difference in the grindability with increasing hafnium contents. We also found that hafnium may be used to harden or strengthen titanium without deteriorating the grindability.

Development of casting technology for manufacturing metal rods with simulated metallic spent fuels

International Nuclear Information System (INIS)

Lee, D. B.; Lee, Y. S.; Woo, Y. M.; Jang, S. J.; Kim, J. D; Kim, C. K.; Shin, Y. J.; Lee, J. H.

1999-01-01

The advanced casting equipment based on the directional solidification method was developed for manufacturing the uranium metal rod having 13.5 mm diameter and 1,200 mm length. In order to prevent surface-shrunk holes revealed easily in course of casting the small diameter and long rods, the vacuum casting furnace has the four pre-heaters equipped with temperature controller. On the other hand, the computer simulation to estimate the defective location and to analyze the solidus behavior of molten uranium in the mold were also performed by using MAGMA Code. As a result of the experimental and theoretical study, the sound rod has successfully been manufactured

Enhanced Injection Molding Simulation of Advanced Injection Molds

Directory of Open Access Journals (Sweden)

Béla Zink

2017-02-01

Full Text Available The most time-consuming phase of the injection molding cycle is cooling. Cooling efficiency can be enhanced with the application of conformal cooling systems or high thermal conductivity copper molds. The conformal cooling channels are placed along the geometry of the injection-molded product, and thus they can extract more heat and heat removal is more uniform than in the case of conventional cooling systems. In the case of copper mold inserts, cooling channels are made by drilling and heat removal is facilitated by the high thermal conductivity coefficient of copper, which is several times that of steel. Designing optimal cooling systems is a complex process; a proper design requires injection molding simulations, but the accuracy of calculations depends on how precise the input parameters and boundary conditions are. In this study, three cooling circuit designs and three mold materials (Ampcoloy 940, 1.2311 (P20 steel, and MS1 steel were used and compared using numerical methods. The effect of different mold designs and materials on cooling efficiency were examined using calculated and measured results. The simulation model was adjusted to the measurement results by considering the joint gap between the mold inserts.

Influence of Reclamation Process on the Ecological Quality of Reclaim Sand

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Dereń M.

2017-12-01

Full Text Available In this article, there were presented results of research on influence of reclamation process on the ecological quality of reclaim sand with furan resin used in nonferrous foundry. The quality of reclaimed sand is mainly define by two group of chemical substances from elution of reclaimed sand: Dissolves Organic Carbon (DOC and Total Dissolves Solids (TDS. Reclaimed sand used in test was prepared in experimental thermal reclaimer and mechanical vibration reclaimer REGMAS installed in Faculty of Foundry Engineering at University Of Science and Technology in Krakow. The reference point is molding sand shaking out and crumble in jaw crusher. Test of elution was made in accredited laboratory in Center For Research and Environmental Control in Katowice up to the standard with Dissolves Organic Carbon (DOC - PN-EN 1484:1999; Total Dissolves Solids (TDS - PN-EN 15216:2010. The standard for elution test is PN-EN 12457- 4:2006. Except that we were made loss of ignition test, to check how many resin was rest on sand grains.

A new low-cost method of reclaiming mixed foundry waste sand based on wet-thermal composite reclamation

OpenAIRE

Fan Zitian; Liu Fuchu; Long Wei

2014-01-01

A lot of mixed clay-resin waste sand from large-scale iron foundries is discharged every day; so mixed waste sand reclamation in low cost and high quality has a great realistic significance. In the study to investigate the possibility of reusing two types of waste foundry sands, resin bonded sand and clay bonded sand which came from a Chinese casting factory, a new low-cost reclamation method of the mixed foundry waste sand based on the wet-thermal composite reclamation was proposed. The wast...

High pressure die casting of Fe-based metallic glass

Science.gov (United States)

Ramasamy, Parthiban; Szabo, Attila; Borzel, Stefan; Eckert, Jürgen; Stoica, Mihai; Bárdos, András

2016-01-01

Soft ferromagnetic Fe-based bulk metallic glass key-shaped specimens with a maximum and minimum width of 25.4 and 5 mm, respectively, were successfully produced using a high pressure die casting (HPDC) method, The influence of die material, alloy temperature and flow rate on the microstructure, thermal stability and soft ferromagnetic properties has been studied. The results suggest that a steel die in which the molten metal flows at low rate and high temperature can be used to produce completely glassy samples. This can be attributed to the laminar filling of the mold and to a lower heat transfer coefficient, which avoids the skin effect in the steel mold. In addition, magnetic measurements reveal that the amorphous structure of the material is maintained throughout the key-shaped samples. Although it is difficult to control the flow and cooling rate of the molten metal in the corners of the key due to different cross sections, this can be overcome by proper tool geometry. The present results confirm that HPDC is a suitable method for the casting of Fe-based bulk glassy alloys even with complex geometries for a broad range of applications. PMID:27725780

High pressure die casting of Fe-based metallic glass.

Science.gov (United States)

Ramasamy, Parthiban; Szabo, Attila; Borzel, Stefan; Eckert, Jürgen; Stoica, Mihai; Bárdos, András

2016-10-11

Soft ferromagnetic Fe-based bulk metallic glass key-shaped specimens with a maximum and minimum width of 25.4 and 5 mm, respectively, were successfully produced using a high pressure die casting (HPDC) method, The influence of die material, alloy temperature and flow rate on the microstructure, thermal stability and soft ferromagnetic properties has been studied. The results suggest that a steel die in which the molten metal flows at low rate and high temperature can be used to produce completely glassy samples. This can be attributed to the laminar filling of the mold and to a lower heat transfer coefficient, which avoids the skin effect in the steel mold. In addition, magnetic measurements reveal that the amorphous structure of the material is maintained throughout the key-shaped samples. Although it is difficult to control the flow and cooling rate of the molten metal in the corners of the key due to different cross sections, this can be overcome by proper tool geometry. The present results confirm that HPDC is a suitable method for the casting of Fe-based bulk glassy alloys even with complex geometries for a broad range of applications.

High pressure die casting of Fe-based metallic glass

Science.gov (United States)

Ramasamy, Parthiban; Szabo, Attila; Borzel, Stefan; Eckert, Jürgen; Stoica, Mihai; Bárdos, András

2016-10-01

Soft ferromagnetic Fe-based bulk metallic glass key-shaped specimens with a maximum and minimum width of 25.4 and 5 mm, respectively, were successfully produced using a high pressure die casting (HPDC) method, The influence of die material, alloy temperature and flow rate on the microstructure, thermal stability and soft ferromagnetic properties has been studied. The results suggest that a steel die in which the molten metal flows at low rate and high temperature can be used to produce completely glassy samples. This can be attributed to the laminar filling of the mold and to a lower heat transfer coefficient, which avoids the skin effect in the steel mold. In addition, magnetic measurements reveal that the amorphous structure of the material is maintained throughout the key-shaped samples. Although it is difficult to control the flow and cooling rate of the molten metal in the corners of the key due to different cross sections, this can be overcome by proper tool geometry. The present results confirm that HPDC is a suitable method for the casting of Fe-based bulk glassy alloys even with complex geometries for a broad range of applications.

Three solutions to a single problem: alternative casting frames for treating infantile idiopathic scoliosis.

Science.gov (United States)

Halanski, Matthew A; Harper, Benjamin L; Cassidy, Jeffry A; Crawford, Haemish A

2013-07-01

This is a technique article discussing 3 alternative frames for casting children with infantile scoliosis. To provide surgeons with alternatives to expensive specialized casting tables to allow local treatment of these children utilizing readily available materials present at most institutions. Casting for infantile scoliosis has become more popular as reports have shown promising results with this technique without the morbidity and complications associated with more invasive procedures. However, without a specialized casting table, treating these patients has been limited to a few centers throughout the country often causing patients to travel large distances to receive care. Three different alternatives to commercially available casting frames are presented. Requirements, setup, and techniques are discussed. Each surgeon has had success with each of these frames. These provide adequate support and traction while allowing enough access to the trunk to apply a well-molded cast. Cotrel/Metha casting for infantile scoliosis can be accomplished without a specialized table using commonly available equipment.

Surface Replication of Molded Products with Microneedle Features in Injection Molding

Science.gov (United States)

Uchiumi, Kazuyasu; Takayama, Tetsuo; Ito, Hiroshi; Inou, Akinori

Micro-molding of microneedle features was conducted using several injection-molding techniques. Injection compression molding and injection molding were performed with supercritical carbon dioxide fluid and with or without vacuum processing inside the mold cavity. Effects of process parameters on processability and surface replication of the molded parts were evaluated. The height replication ratio for microneedles was improved using injection compression molding. At a shorter compression stroke, the needle height was improved, and the influence of compression delay time was also small. Moreover, the effects of vacuum processing inside the mold cavity under the filling process were slight. The height replication ratio for microneedles showed the highest values using injection molding using supercritical carbon dioxide fluid with vacuum inside the mold cavity.

Influence of Cast Iron Structure on the Glassmold Equipment Operational Defects

Directory of Open Access Journals (Sweden)

I. O. Leushin

2015-01-01

Full Text Available The growing demand for glass packaging contributes to the increase in production capacity of glass-container plants. Their equipment (cast iron glass-forming sets operates in continuous mode under complex cyclic thermal loads, which lead to the formation of operational defects on the working surfaces of details: graphite falling, cracks, oxidation, etc. Particular influence on the formation of these defects renders the microstructure of the material at the time of installation of details on the line.The article identifies the causes for formation of operational defects, formulates the ways to remedy them and prevent their occurrence.The authors studied details made from grey cast iron with flake and spherical forms of graphite. It is found that in the process of exploitation of the material is greatly reducing its hardness, strength, resistance to oxidation through of graphitization processes, chemical interaction of glass and iron, shock loads working edges. It is proved that the choice of initial microstructure of cast iron (the metal base, the graphite form, the presence of structural-free cementite exercises a determining influence on the durability of the mold tooling. The article proposes differential (layered arrangement of the graphite phase of cast iron in the alloy matrix (ferrite. This arrangement of high-carbon phase can simultaneously increase the thermal and oxidation resistance of the material. The formation of a layered structure of iron is produced by the intensification of the processes of alloying, modifying and directional freezing the melt.These data can be used to select the material of details by manufacturers glass-molds tooling.

Formation Mechanism of Surface Crack in Low Pressure Casting of A360 Alloy

Science.gov (United States)

Liu, Shan-Guang; Cao, Fu-Yang; Ying, Tao; Zhao, Xin-Yi; Liu, Jing-Shun; Shen, Hong-Xian; Guo, Shu; Sun, Jian-Fei

2017-12-01

A surface crack defect is normally found in low pressure castings of Al alloy with a sudden contraction structure. To further understand the formation mechanism of the defect, the mold filling process is simulated by a two-phase flow model. The experimental results indicate that the main reason for the defect deformation is the mismatching between the height of liquid surface in the mold and pressure in the crucible. In the case of filling, a sudden contraction structure with an area ratio smaller than 0.5 is obtained, and the velocity of the liquid front increases dramatically with the influence of inertia. Meanwhile, the pressurizing speed in the crucible remains unchanged, resulting in the pressure not being able to support the height of the liquid level. Then the liquid metal flows back to the crucible and forms a relatively thin layer solidification shell on the mold wall. With the increasing pressure in the crucible, the liquid level rises again, engulfing the shell and leading to a surface crack. As the filling velocity is characterized by the damping oscillations, surface cracks will form at different heights. The results shed light on designing a suitable pressurizing speed for the low pressure casting process.

Fractography of STIR casted Al-ZrO2 composites

International Nuclear Information System (INIS)

Baghchesara, M. A.; Abdizadeh, H.; Baharvandi, H. R.

2009-01-01

In this study, Al-ZrO 2 composites were produced by Vortex method using ZrO 2 powder with 1 micron average diameter as reinforce particles and Al-356 as the matrix metal. The melt composites were stirred for 13 minutes, then casted into a metallic mold. Different samples of 5, 10 and 15 volume percent of ZrO 2 , in different casting temperatures of 750, 850 and 950 d eg C were produced. The latter 2 casting temperatures are not a common practice but were chosen to enhance fluidity. Effects of volume percent of ZrO 2 particles and casting temperature on tensile strength, microstructure, and fracture surfaces of Al-ZrO 2 composites have been investigated. The highest tensile strength was achieved in the specimen containing 15 vol. % ZrO 2 produced at 750 d eg C which shows an increase of 60% in comparison to the Al-356 non-reinforced alloy. Microscopic investigations of fracture surfaces revealed that fracture in a brittle manner with little or no necking happening. By increasing ZrO 2 content and casting temperature, the composites fracture goes in a more severely brittle manner.

DOE applied to study the effect of process parameters on silicon spacing in lost foam Al-Si-Cu alloy casting

International Nuclear Information System (INIS)

Shayganpour, A; Izman, S; Idris, M H; Jafari, H

2012-01-01

Lost foam casting as a relatively new manufacturing process is extensively employed to produce sound complicated castings. In this study, an experimental investigation on lost foam casting of an Al-Si-Cu aluminium cast alloy was conducted. The research was aimed in evaluating the effect of different pouring temperatures, slurry viscosities, vibration durations and sand grain sizes on eutectic silicon spacing of thin-wall castings. A stepped-pattern was used in the study and the focus of the investigations was at the thinnest 3 mm section. A full two-level factorial design experimental technique was used to plan the experiments and afterwards identify the significant factors affecting casting silicon spacing. The results showed that pouring temperature and its interaction with vibration time have pronounced effect on eutectic silicon phase size. Increasing pouring temperature coarsened the eutectic silicon spacing while the higher vibration time diminished coarsening effect. Moreover, no significant effects on silicon spacing were found with variation of sand size and slurry viscosity.

Flow Dynamics of green sand in the DISAMATIC moulding process using Discrete element method (DEM)

DEFF Research Database (Denmark)

Hovad, Emil; Larsen, P.; Walther, Jens Honore

2015-01-01

casting process. Depending on the actual casting geometry the mould can be geometrically quite complex involving e.g. shadowing effects and this is directly reflected in the sand flow during the moulding process. In the present work a mould chamber with “ribs” at the walls is chosen as a baseline geometry...

Quantitative assessment of Aluminium cast Alloys` structural parameters to optimize ITS properties

Directory of Open Access Journals (Sweden)

L. Kuchariková

2017-01-01

Full Text Available The present work deals with evaluation of eutectic Si (its shape, size, and distribution, dendrite cell size and dendrite arm spacing in aluminium cast alloys which were cast into different moulds (sand and metallic. Structural parameters were evaluated using NIS-Elements image analyser software. This software is imaging analysis software for the evaluation, capture, archiving and automated measurement of structural parameters. The control of structural parameters by NIS Elements shows that optimum mechanical properties of aluminium cast alloys strongly depend on the distribution, morphology, size of eute ctic Si and matrix parameters.

High Cost/High Risk Components to Chalcogenide Molded Lens Model: Molding Preforms and Mold Technology

Energy Technology Data Exchange (ETDEWEB)

Bernacki, Bruce E.

2012-10-05

This brief report contains a critique of two key components of FiveFocal's cost model for glass compression molding of chalcogenide lenses for infrared applications. Molding preforms and mold technology have the greatest influence on the ultimate cost of the product and help determine the volumes needed to select glass molding over conventional single-point diamond turning or grinding and polishing. This brief report highlights key areas of both technologies with recommendations for further study.

Geologic continuous casting below continental and deep-sea detachment faults and at the striated extrusion of Sacsayhuaman, Peru

Science.gov (United States)

Spencer, J.E.

1999-01-01

In the common type of industrial continuous casting, partially molten metal is extruded from a vessel through a shaped orifice called a mold in which the metal assumes the cross-sectional form of the mold as it cools and solidifies. Continuous casting can be sustained as long as molten metal is supplied and thermal conditions are maintained. I propose that a similar process produced parallel sets of grooves in three geologic settings, as follows: (1) corrugated metamorphic core complexes where mylonized mid-crustal rocks were exhumed by movement along low-angle normal faults known as detachment faults; (2) corrugated submarine surfaces where ultramafic and mafic rocks were exhumed by normal faulting within oceanic spreading centers; and (3) striated magma extrusions exemplified by the famous grooved outcrops at the Inca fortress of Sacsayhuaman in Peru. In each case, rocks inferred to have overlain the corrugated surface during corrugation genesis molded and shaped a plastic to partially molten rock mass as it was extruded from a moderate- to high-temperature reservoir.

Reuse of waste iron as a partial replacement of sand in concrete.

Science.gov (United States)

Ismail, Zainab Z; Al-Hashmi, Enas A

2008-11-01

One of the major environmental issues in Iraq is the large quantity of waste iron resulting from the industrial sector which is deposited in domestic waste and in landfills. A series of 109 experiments and 586 tests were carried out in this study to examine the feasibility of reusing this waste iron in concrete. Overall, 130 kg of waste iron were reused to partially replace sand at 10%, 15%, and 20% in a total of 1703 kg concrete mixtures. The tests performed to evaluate waste-iron concrete quality included slump, fresh density, dry density, compressive strength, and flexural strength tests: 115 cubes of concrete were molded for the compressive strength and dry density tests, and 87 prisms were cast for the flexural strength tests. This work applied 3, 7, 14, and 28 days curing ages for the concrete mixes. The results confirm that reuse of solid waste material offers an approach to solving the pollution problems that arise from an accumulation of waste in a production site; in the meantime modified properties are added to the concrete. The results show that the concrete mixes made with waste iron had higher compressive strengths and flexural strengths than the plain concrete mixes.

Wetting Behavior of Mold Flux Droplet on Steel Substrate With or Without Interfacial Reaction

Science.gov (United States)

Zhou, Lejun; Li, Jingwen; Wang, Wanlin; Sohn, Il

2017-08-01

The slag entrapment in mold tends to cause severe defects on the slab surface, especially for casting steels containing active alloy elements such as Al, Ti, and Mn. The wetting behavior of molten mold flux on the initial solidified shell is considered to be a key factor to determine the entrapment of mold slag on the shell surface. Therefore, the wetting behavior of mold flux droplet on the steel substrate with or without interfacial reaction was investigated by the sessile drop method. The results indicated that the melting process of mold flux has a significant influence on the variation of contact angle, and the final contact angle for Flux1 droplet on 20Mn23AlV is only 15 deg, which is lower than the other two cases due to the intensive interracial reactions occurring in this case. In addition, the thickness of the interaction layer for the case of Flux1 on 20Mn23AlV is 10- μm greater than the other two cases, which confirms that the most intensive reactions occurred at the interface area. The microstructure and element distribution at the interface analyzed by a scanning electron microscope (SEM) and energy dispersive spectrum (EDS) suggested that the increase of wettability of mold flux droplet on the steel substrate is caused by the migration of Al, Mn, and Si elements occurring in the vicinity of the interface. The results obtained in this article can reveal the mechanism of flux entrapment by hook or shell and provide theoretic guidance for mold flux design and optimization.

Semi-continuous casting of magnesium alloy AZ91 using a filtered melt delivery system

Directory of Open Access Journals (Sweden)

Mainul Hasan

2015-12-01

Full Text Available A 3-D numerical simulation of an industrial-sized slab caster for magnesium alloy AZ91 has been carried out for the steady state operational phase of the caster. The simulated model consists of an open-top melt delivery system fitted with a porous filter near the hot-top. The melt flow through the porous filter was modeled on the basis of Brinkmann-Forchimier-Extended non-Darcy model for turbulent flow. An in-house 3-D CFD code was modified to account for the melt flow through the porous filter. Results are obtained for four casting speeds namely, 40, 60, 80, and 100 mm/min. The metal-mold contact region as well as the convective heat transfer coefficient at the mold wall were also varied. In addition to the above, the Darcy number for the porous media was also changed. All parametric studies were performed for a fixed inlet melt superheat of 64 °C. The results are presented pictorially in the form of temperature and velocity fields. The sump depth, mushy region thickness, solid shell thickness at the exit of the mold and axial temperature profiles are also presented and correlated with the casting speed through regression analysis.

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

International Nuclear Information System (INIS)

Bai Jing; Sun Yangshan; Xue Feng; Qiang Jing

2012-01-01

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 α-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 11 La 3 eutectic, and simultaneously Mg 17 Al 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 17 Al 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 11 La 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.

Numerical simulation and optimization of Al alloy cylinder body by low pressure die casting

Directory of Open Access Journals (Sweden)

Mi Guofa

2008-05-01

Full Text Available Shrinkage defects can be formed easily at Critical location during low pressure die casting (LPDC of aluminum alloy cylinder body. It has harmful effect on the products. Mold fi lling and solidifi cation process of a cylinder body was simulated by using of Z-CAST software. The casting method was improved based on the simulation results. In order to create effective feeding passage, the structure of casting was modifi ed by changing the location of strengthening ribs at the bottom, without causing any adverse effect on the part’s performance. Inserting copper billet at suitable location of the die is a valid way to create suitable solidifi cation sequence that is benefi cial to the feeding. Using these methods, the shrinkage defect was completely eliminated at the critical location.

Prediction of hot-ductility of steels during continuous casting using artificial neural networks

International Nuclear Information System (INIS)

Liu, W.J.; Emadi, D.; Essadiqi, E.

2000-01-01

During continuous casting, transversal cracks can be developed due to tensile stress in temperature regions where the steel exhibits a low ductility. The cracking tendency during continuous casting depends on the steel chemistry and the casting parameters such as lubrication, mold type, secondary cooling and bending/unbending temperatures. To prevent cracking one needs to predict the hot-ductility of a material under continuous-casting conditions. However, hot-ductility is one of the poorly understood material behaviors and cannot be readily modeled using conventional techniques. In the present study, we used an alternative method, namely Artificial Neural Networks (ANN), to model the ductility of a steel under continuous casting conditions. A hot-ductility database was established based on published literature. Several standard three-layer ANN models were then trained using data randomly selected from the database. The outputs of the ANN models were subsequently compared with the remaining data in the database. The results indicate that ANN is a suitable modelling technique for hot-ductility prediction. (author)

Centrifugally cast Zn-27Al-xMg-ySi alloys and their in situ (Mg2Si + Si)/ZA27 composites

International Nuclear Information System (INIS)

Wang Qudong; Chen Yongjun; Chen Wenzhou; Wei Yinhong; Zhai Chunquan; Ding Wenjiang

2005-01-01

Effects of composition, mold temperature, rotating rate and modification on microstructure of centrifugally cast Zn-27Al-xMg-ySi alloys have been investigated. In situ composites of Zn-27Al-6.3Mg-3.7Si and Zn-27Al-9.8Mg-5.2Si alloys were fabricated by centrifugal casting using heated permanent mold. These composites consist of three layers: inner layer segregates lots of blocky primary Mg 2 Si and a litter blocky primary Si, middle layer contains without primary Mg 2 Si and primary Si, outer layer contains primary Mg 2 Si and primary Si. The position, quantity and distribution of primary Mg 2 Si and primary Si in the composites are determined jointly by alloy composition, solidification velocity under the effect of centrifugal force and their floating velocity inward. Na salt modifier can refine grain and primary Mg 2 Si and make primary Mg 2 Si distribute more evenly and make primary Si nodular. For centrifugally cast Zn-27Al-3.2Mg-1.8Si alloy, the microstructures of inner layer, middle layer and outer layer are almost similar, single layer materials without primary Mg 2 Si and primary Si are obtained, and their grain sizes increased with the mold temperature increasing

Vacuum-induction melting, refining, and casting of uranium and its alloys

Energy Technology Data Exchange (ETDEWEB)

Jackson, R J

1989-10-11

The vacuum-induction melting (VIM), refining, and casting of uranium and its alloys are discussed. Emphasis is placed on historical development, VIM equipment, crucible and mold design, furnace atmospheres, melting parameters, impurity pickup, ingot quality, and economics. The VIM procedures used to produce high-purity, high-quality sound ingots at the US Department of Energy Rocky Flats Plant are discussed in detail.

Nutritional and Microbial Parameters of Earthworm Cast, Termite Mound and Surrounding Bulk Soil

OpenAIRE

Kawaguchi, Sadao; Nishi, Shingo

2007-01-01

A comparative analysis of nutritional and microbial parameters was conducted on two types of biogenetic structures of earthworm cast (8.7 cm in height, 7 casts/1m×1m) formed by litter eating Pheretima sp., and mound (64 cm in height, 1.0 mounds/10m×50m) built by fungus growing termite, Macrotermes gilvus, and compared to the surrounding bulk soil as control in the tropical monsoon forest in Cu Chi National Park of Viet Nam. The proportion of the sand in the earthworm cast was higher than in t...

Mechanical properties and grindability of dental cast Ti-Nb alloys.

Science.gov (United States)

Kikuchi, Masafumi; Takahashi, Masatoshi; Okuno, Osamu

2003-09-01

Aiming at developing a dental titanium alloy with better mechanical properties and machinability than unalloyed titanium, a series of Ti-Nb alloys with Nb concentrations up to 30% was made. They were cast into magnesia-based molds using a dental casting machine and the mechanical properties and grindability of the castings were examined. The hardness of the alloys with Nb concentrations of 5% and above was significantly higher than that of titanium. The yield strength and tensile strength of the alloys with Nb concentrations of 10% and above were significantly higher than those of titanium, while the elongation was significantly lower. A small addition of niobium to titanium did not contribute to improving the grindability of titanium. The Ti-30% Nb alloy exhibited significantly better grindability at low grinding speed with higher hardness, strength, and Young's modulus than titanium, presumably due to precipitation of the omega phase in the beta matrix.

Rapid control of mold temperature during injection molding process

Energy Technology Data Exchange (ETDEWEB)

Liparoti, Sara; Titomanlio, Giuseppe [Department of Industrial Engineering, University of Salerno Via Giovanni Paolo II, 132, 84084 Fisciano (Italy); Hunag, Tsang Min; Cakmak, Mukerrem [Department of Polymer Engineering, The University of Akron, Akron, OH 44325 (United States); Sorrentino, Andrea [Institute for Polymers, Composite and Biomaterials (IPCB) - CNR, P. Enrico Fermi 1, 80055 Portici (Italy)

2015-05-22

The control of mold surface temperature is an important factor that determines surface morphology and its dimension in thickness direction. It can also affect the frozen molecular orientation and the mold surface replicability in injection molded products. In this work, thin thermally active films were used to quickly control the mold surface temperature. In particular, an active high electrical conductivity carbon black loaded polyimide composites sandwiched between two insulating thin polymeric layers was used to condition the mold surface. By controlling the heating time, it was possible to control precisely the temporal variation of the mold temperature surface during the entire cycle. The surface heating rate was about 40°C/s and upon contact with the polymer the surface temperature decreased back to 40°C within about 5 s; the overall cycle time increased only slightly. The effect on cross section sample morphology of samples of iPP were analyzed and discussed on the basis of the recorded temperature evolution.

Moisture diffusion coefficients determination of furan bonded sands and water based foundry coatings

DEFF Research Database (Denmark)

Di Muoio, Giovanni Luca; Tiedje, Niels Skat

2016-01-01

Moisture content in furan bonded sand and water based coatings can be one of the main causes for gas related defects in large cast iron parts. Moisture diffusion coefficients for these materials are needed to precisely predict the possible moisture levels in foundry moulds. In this study, we first...... provide an example on how it is possible to apply this knowledge to estimate moisture variation in a sand mould during production....

Sequencing of Dust Filter Production Process Using Design Structure Matrix (DSM)

Science.gov (United States)

Sari, R. M.; Matondang, A. R.; Syahputri, K.; Anizar; Siregar, I.; Rizkya, I.; Ursula, C.

2018-01-01

Metal casting company produces machinery spare part for manufactures. One of the product produced is dust filter. Most of palm oil mill used this product. Since it is used in most of palm oil mill, company often have problems to address this product. One of problem is the disordered of production process. It carried out by the job sequencing. The important job that should be solved first, least implement, while less important job and could be completed later, implemented first. Design Structure Matrix (DSM) used to analyse and determine priorities in the production process. DSM analysis is sort of production process through dependency sequencing. The result of dependency sequences shows the sequence process according to the inter-process linkage considering before and after activities. Finally, it demonstrates their activities to the coupled activities for metal smelting, refining, grinding, cutting container castings, metal expenditure of molds, metal casting, coating processes, and manufacture of molds of sand.

A new production technique for wear resistant ring-hammers

Directory of Open Access Journals (Sweden)

Li Shifeng

2011-11-01

Full Text Available Based on a great number of laboratory experiments, a new technique has been developed for producing wear resistant ring-hammers. In this technology, lost foam casting with iron sand was combined to make mold; a special alloy was used to inoculate the molten steel, and proper heat treatment was used to further improve mechanical properties of wear resistant ring-hammers. The influence of this new production technology on the microstructure and mechanical properties of wear resistant ring-hammers was studied. Results show that iron sand molding, having the inherent characteristic of sand molding, changes the type of metallic compounds, refines crystal grains and increases the fineness of microstructure. Practical experience verified that the properties of the ring-hammers produced with this new technique are as follows: tensile strength (Rm 720 MPa, impact toughness (ak > 210 J•cm-2 and hardness > 200 HB. After water quenching from 1,080℃ (holding for 4 h and tempering at 320℃ for 3 h, the best wear resistance is obtained, and the wear resistance is 1.6 times higher than that of common high manganese ring-hammers.

A computational study of low-head direct chill slab casting of aluminum alloy AA2024

Science.gov (United States)

Hasan, Mainul; Begum, Latifa

2016-04-01

The steady state casting of an industrial-sized AA2024 slab has been modeled for a vertical low-head direct chill caster. The previously verified 3-D CFD code is used to investigate the solidification phenomena of the said long-range alloy by varying the pouring temperature, casting speed and the metal-mold contact heat transfer coefficient from 654 to 702 °C, 60-180 mm/min, and 1.0-4.0 kW/(m2 K), respectively. The important predicted results are presented and thoroughly discussed.

Allergies, asthma, and molds

Science.gov (United States)

Reactive airway - mold; Bronchial asthma - mold; Triggers - mold; Allergic rhinitis - pollen ... Things that make allergies or asthma worse are called triggers. Mold is a common trigger. When your asthma or allergies become worse due to mold, you are ...

The Effect of Shell Thickness, Insulation and Casting Temperature on Defects Formation During Investment Casting of Ni-base Turbine Blades

Directory of Open Access Journals (Sweden)

Raza M.

2015-12-01

Full Text Available Turbine blades have complex geometries with free form surface. Blades have different thickness at the trailing and leading edges as well as sharp bends at the chord-tip shroud junction and sharp fins at the tip shroud. In investment casting of blades, shrinkage at the tip-shroud and cord junction is a common casting problem. Because of high temperature applications, grain structure is also critical in these castings in order to avoid creep. The aim of this work is to evaluate the effect of different process parameters, such as, shell thickness, insulation and casting temperature on shrinkage porosity and grain size. The test geometry used in this study was a thin-walled air-foil structure which is representative of a typical hot-gas-path rotating turbine component. It was observed that, in thin sections, increased shell thickness helps to increase the feeding distance and thus avoid interdendritic shrinkage. It was also observed that grain size is not significantly affected by shell thickness in thin sections. Slower cooling rate due to the added insulation and steeper thermal gradient at metal mold interface induced by the thicker shell not only helps to avoid shrinkage porosity but also increases fill-ability in thinner sections.

Integrated Modeling of Process, Structures and Performance in Cast Parts

DEFF Research Database (Denmark)

Kotas, Petr

This thesis deals with numerical simulations of gravity sand casting processes for the production of large steel parts. The entire manufacturing process is numerically modeled and evaluated, taking into consideration mould filling, solidification, solid state cooling and the subsequent stress build...... and to defects occurrence. In other words, it is desired to eliminate all of the potential casting defects and at the same time to maximize the casting yield. The numerical optimization algorithm then takes these objectives and searches for a set of the investigated process, design or material parameters e.......g. chill design, riser design, gating system design, etc., which would satisfy these objectives the most. The first step in the numerical casting process simulation is to analyze mould filling where the emphasis is put on the gating system design. There are still a lot of foundry specialists who ignore...

Development of a New Ferrous Aluminosilicate Refractory Material for Investment Casting of Aluminum Alloys

Science.gov (United States)

Yuan, Chen; Jones, Sam; Blackburn, Stuart

2012-12-01

Investment casting is a time-consuming, labour intensive process, which produces complex, high value-added components for a variety of specialised industries. Current environmental and economic pressures have resulted in a need for the industry to improve current casting quality, reduce manufacturing costs and explore new markets for the process. Alumino-silicate based refractories are commonly used as both filler and stucco materials for ceramic shell production. A new ceramic material, norite, is now being produced based on ferrous aluminosilicate chemistry, having many potential advantages when used for the production of shell molds for casting aluminum alloy. This paper details the results of a direct comparison made between the properties of a ceramic shell system produced with norite refractories and a typical standard refractory shell system commonly used in casting industry. A range of mechanical and physical properties of the systems was measured, and a full-scale industrial casting trial was also carried out. The unique properties of the norite shell system make it a promising alternative for casting aluminum based alloys in the investment foundry.

Microcapillary Features in Silicon Alloyed High-Strength Cast Iron

Directory of Open Access Journals (Sweden)

R.K. Hasanli

2017-04-01

Full Text Available Present study explores features of silicon micro capillary in alloyed high-strength cast iron with nodular graphite (ductile iron produced in metal molds. It identified the nature and mechanism of micro liquation of silicon in a ductile iron alloyed with Nickel and copper, and demonstrated significant change of structural-quality characteristics. It was concluded that the matrix of alloyed ductile iron has a heterogeneous structure with cross reinforcement and high-silicon excrement areas.

Indirect three-dimensional printing of synthetic polymer scaffold based on thermal molding process

International Nuclear Information System (INIS)

Park, Jeong Hun; Jung, Jin Woo; Cho, Dong-Woo; Kang, Hyun-Wook

2014-01-01

One of the major issues in tissue engineering has been the development of three-dimensional (3D) scaffolds, which serve as a structural template for cell growth and extracellular matrix formation. In scaffold-based tissue engineering, 3D printing (3DP) technology has been successfully applied for the fabrication of complex 3D scaffolds by using both direct and indirect techniques. In principle, direct 3DP techniques rely on the straightforward utilization of the final scaffold materials during the actual scaffold fabrication process. In contrast, indirect 3DP techniques use a negative mold based on a scaffold design, to which the desired biomaterial is cast and then sacrificed to obtain the final scaffold. Such indirect 3DP techniques generally impose a solvent-based process for scaffold fabrication, resulting in a considerable increase in the fabrication time and poor mechanical properties. In addition, the internal architecture of the resulting scaffold is affected by the properties of the biomaterial solution. In this study, we propose an advanced indirect 3DP technique using projection-based micro-stereolithography and an injection molding system (IMS) in order to address these challenges. The scaffold was fabricated by a thermal molding process using IMS to overcome the limitation of the solvent-based molding process in indirect 3DP techniques. The results indicate that the thermal molding process using an IMS has achieved a substantial reduction in scaffold fabrication time and has also provided the scaffold with higher mechanical modulus and strength. In addition, cell adhesion and proliferation studies have indicated no significant difference in cell activity between the scaffolds prepared by solvent-based and thermal molding processes. (paper)

Development of a manufacturing technology of compacted graphite iron castings from a cupola furnace

Directory of Open Access Journals (Sweden)

O. Bouska

2012-01-01

Full Text Available Compacted graphite iron, also known as vermicular cast iron or semiductile cast iron is a modern material, the production of which is increasing globaly. Recently this material has been very often used in automotive industry. This paper reviews some findigs gained during the development of the manufacturing technology of compacted graphite iron under the conditions in Slévárna Heunisch Brno, Ltd. The new technology assumes usage of cupola furnace for melting and is beeing developed for production of castings weighing up to 300 kilograms poured into bentonite sand moulds.

Research on investment casting of TiAl alloy agitator treated by HIP and HT

Directory of Open Access Journals (Sweden)

LI Zhen-xi

2007-05-01

Full Text Available Using TiAl alloy to substitute superalloy is a hot topic in aeroengine industry because of its low density,high elevated temperature strength, and anti-oxidization ability. In this research, Ti-47.5AL-2Cr-2Nb-0.2B alloy was used as the test material. By applying a combination process of ceramic shell mold and core making, vacuum arc melting and centrifugal pouring, and heat isostatic pressing (HIP and heat treatment (HT etc., the TiAl vortex agitator casting for aeroengine was successfully made. This paper introduced key techniques in making the TiAl vortex agitator with investment casting process, provided some experimental results including mechanical properties and machinability, and explained some concerns that could affect applications of TiAl castings.

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.

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...

Process to Continuously Melt, Refine and Cast High Quality Steel

Energy Technology Data Exchange (ETDEWEB)

None

2005-09-01

The purpose of this project is to conduct research and development targeted at designing a revolutionary steelmaking process. This process will deliver high quality steel from scrap to the casting mold in one continuous process and will be safer, more productive, and less capital intensive to build and operate than conventional steelmaking. The new process will produce higher quality steel faster than traditional batch processes while consuming less energy and other resources.

Ageless Aluminum-Cerium-Based Alloys in High-Volume Die Casting for Improved Energy Efficiency

Science.gov (United States)

Stromme, Eric T.; Henderson, Hunter B.; Sims, Zachary C.; Kesler, Michael S.; Weiss, David; Ott, Ryan T.; Meng, Fanqiang; Kassoumeh, Sam; Evangelista, James; Begley, Gerald; Rios, Orlando

2018-04-01

Strong chemical reactions between Al and Ce lead to the formation of intermetallics with exceptional thermal stability. The rapid formation of intermetallics directly from the liquid phase during solidification of Al-Ce alloys leads to an ultrafine microconstituent structure that effectively strengthens as-cast alloys without further microstructural optimization via thermal processing. Die casting is a high-volume manufacturing technology that accounts for greater than 40% of all cast Al products, whereas Ce is highly overproduced as a waste product of other rare earth element (REE) mining. Reducing heat treatments would stimulate significant improvements in manufacturing energy efficiency, exceeding (megatonnes/year) per large-scale heat-treatment line. In this study, multiple compositions were evaluated with wedge mold castings to test the sensitivity of alloys to the variable solidification rate inherent in high-pressure die casting. Once a suitable composition was determined, it was successfully demonstrated at 800 lbs/h in a 600-ton die caster, after which the as-die cast parts performed similarly to ubiquitous A380 in the same geometry without requiring heat treatment. This work demonstrates the compatibility of Al REE alloys with high-volume die-casting applications with minimal heat treatments.

Ageless Aluminum-Cerium-Based Alloys in High-Volume Die Casting for Improved Energy Efficiency

Science.gov (United States)

Stromme, Eric T.; Henderson, Hunter B.; Sims, Zachary C.; Kesler, Michael S.; Weiss, David; Ott, Ryan T.; Meng, Fanqiang; Kassoumeh, Sam; Evangelista, James; Begley, Gerald; Rios, Orlando

2018-06-01

Strong chemical reactions between Al and Ce lead to the formation of intermetallics with exceptional thermal stability. The rapid formation of intermetallics directly from the liquid phase during solidification of Al-Ce alloys leads to an ultrafine microconstituent structure that effectively strengthens as-cast alloys without further microstructural optimization via thermal processing. Die casting is a high-volume manufacturing technology that accounts for greater than 40% of all cast Al products, whereas Ce is highly overproduced as a waste product of other rare earth element (REE) mining. Reducing heat treatments would stimulate significant improvements in manufacturing energy efficiency, exceeding (megatonnes/year) per large-scale heat-treatment line. In this study, multiple compositions were evaluated with wedge mold castings to test the sensitivity of alloys to the variable solidification rate inherent in high-pressure die casting. Once a suitable composition was determined, it was successfully demonstrated at 800 lbs/h in a 600-ton die caster, after which the as-die cast parts performed similarly to ubiquitous A380 in the same geometry without requiring heat treatment. This work demonstrates the compatibility of Al REE alloys with high-volume die-casting applications with minimal heat treatments.

Evaluation of marginal gap of Ni-Cr copings made with conventional and accelerated casting techniques.

Science.gov (United States)

Tannamala, Pavan Kumar; Azhagarasan, Nagarasampatti Sivaprakasam; Shankar, K Chitra

2013-01-01

Conventional casting techniques following the manufacturers' recommendations are time consuming. Accelerated casting techniques have been reported, but their accuracy with base metal alloys has not been adequately studied. We measured the vertical marginal gap of nickel-chromium copings made by conventional and accelerated casting techniques and determined the clinical acceptability of the cast copings in this study. Experimental design, in vitro study, lab settings. Ten copings each were cast by conventional and accelerated casting techniques. All copings were identical, only their mold preparation schedules differed. Microscopic measurements were recorded at ×80 magnification on the perpendicular to the axial wall at four predetermined sites. The marginal gap values were evaluated by paired t test. The mean marginal gap by conventional technique (34.02 μm) is approximately 10 μm lesser than that of accelerated casting technique (44.62 μm). As the P value is less than 0.0001, there is highly significant difference between the two techniques with regard to vertical marginal gap. The accelerated casting technique is time saving and the marginal gap measured was within the clinically acceptable limits and could be an alternative to time-consuming conventional techniques.

The simulation of magnesium wheel low pressure die casting based on PAM-CASTTM

International Nuclear Information System (INIS)

Peng Yinghong; Wang Yingchun; Li Dayong; Zeng Xiaoqin

2004-01-01

Magnesium is the lightest metal commonly used in engineering, with various excellent characteristics such as high strength and electromagnetic interference shielding capability. Particularly, the usage of magnesium in automotive industry can meet better the need to reduce fuel consumption and CO2 emissions. Nowadays, most current magnesium components in automobiles are made by die casting. In this paper, commercial software for die casting, PAM-CAST TM , was utilized to simulate the low pressure die casting process of magnesium wheel. Through calculating temperature field and velocity field during filling and solidification stages, the evolution of temperature distribution and liquid fraction was analyzed. Then, the potential defects including the gas entrapments in the middle of the spokes, shrinkages between the rim and the spokes were forecasted. The analytical results revealed that the mold geometry and die casting parameters should be improved in order to get the sound magnesium wheel. The reasons leading to these defects were also analyzed and the solutions to eliminate them were put forward. Furthermore, through reducing the pouring velocity, the air gas entrapments and partial shrinkages were eliminated effectively

Hierarchical modeling of professional skills in the field of castings manufacture engineering

Science.gov (United States)

Samuilă, V.; Soporan, V. F.; Conțiu, G.; Pădurețu, S.; Lehene, T. R.; Vescan, M. M.

2017-06-01

The paper presents a method of hierarchizing professional skills in the manufacturing of molded parts (castings) by using and adapting the FAHP algorithm (Fuzzy Analitical Hierarchy Process). Assessments are made regarding the peculiarities of the professional training process, specifying the activities to be carried out and the competences necessary for their development. The contribution of the design of the method extends to the design of the hierarchy system architecture, the linguistic determination of the importance of each characteristic, the construction of the fuzzy ordering matrices for each stage of the process, the determination of the share of the characteristics for each hierarchy step and establishing the hierarchy of the characteristics taking into account the influences of the others, grouped at the level of the steps and within the global matrix. The research carried out represents the support for generating an instrument of hierarchy of professional competencies that can be used in various professional and institutional contexts. Case study on the hierarchy of professional skills in the manufacturing of molded parts engineering. Keywords: Materials engineering, castings manufacture professional skills, hierarchy, AHP method, standard occupational curriculum.

Grindability of cast Ti-Cu alloys.

Science.gov (United States)

Kikuchi, Masafumi; Takada, Yukyo; Kiyosue, Seigo; Yoda, Masanobu; Woldu, Margaret; Cai, Zhuo; Okuno, Osamu; Okabe, Toru

2003-07-01

The purpose of the present study was to evaluate the grindability of a series of cast Ti-Cu alloys in order to develop a titanium alloy with better grindability than commercially pure titanium (CP Ti), which is considered to be one of the most difficult metals to machine. Experimental Ti-Cu alloys (0.5, 1.0, 2.0, 5.0, and 10.0 mass% Cu) were made in an argon-arc melting furnace. Each alloy was cast into a magnesia mold using a centrifugal casting machine. Cast alloy slabs (3.5 mm x 8.5 mm x 30.5 mm), from which the hardened surface layer (250 microm) was removed, were ground using a SiC abrasive wheel on an electric handpiece at four circumferential speeds (500, 750, 1000, or 1250 m/min) at 0.98 N (100 gf). Grindability was evaluated by measuring the amount of metal volume removed after grinding for 1min. Data were compared to those for CP Ti and Ti-6Al-4V. For all speeds, Ti-10% Cu alloy exhibited the highest grindability. For the Ti-Cu alloys with a Cu content of 2% or less, the highest grindability corresponded to an intermediate speed. It was observed that the grindability increased with an increase in the Cu concentration compared to CP Ti, particularly for the 5 or 10% Cu alloys at a circumferential speed of 1000 m/min or above. By alloying with copper, the cast titanium exhibited better grindability at high speed. The continuous precipitation of Ti(2)Cu among the alpha-matrix grains made this material less ductile and facilitated more effective grinding because small broken segments more readily formed.

Effects of heat treatment on the microstructure and mechanical properties of AA2618 DC cast alloy

International Nuclear Information System (INIS)

Elgallad, E.M.; Shen, P.; Zhang, Z.; Chen, X.-G.

2014-01-01

Highlights: • The microstructure and mechanical properties of AA2618 DC cast alloy were studied. • The Al 2 CuMg, Al 2 Cu, Al 7 Cu 4 Ni, Al 7 Cu 2 (Fe,Ni) and Al 9 FeNi phases were identified. • Solution treatment at 530 °C for 5 h is the optimum solution treatment. • Different combinations of strength and ductility can be achieved. • The strengthening of AA2618 DC cast alloy was caused by GPB zones and S′ phase. - Abstract: Direct chill (DC) cast ingot plates of AA2618 alloy have been increasingly used for large-mold applications in the plastics and automotive industries. The effects of different heat treatments on the microstructure and mechanical properties of AA2618 DC cast alloy were investigated using scanning electron microscopy (SEM), transmission electron microscopy (TEM) and hardness and tensile testing. The as-cast microstructure contained a considerable amount of coarse intermetallic phases, including Al 2 CuMg, Al 2 Cu, Al 7 Cu 4 Ni, Al 7 Cu 2 (Fe,Ni) and Al 9 FeNi, resulting in poor mechanical properties. Solution treatment at 530 °C for 5 h dissolved the first three phases into the solid solution and consequently improved the mechanical properties of the alloy. By utilizing the appropriate aging temperature and time, different combinations of strength and ductility could be obtained to fulfill the design requirements of large-mold applications. The strengthening of AA2618 DC cast alloy under the aging conditions studied was caused by GPB zones and S′ precipitates. The evolution of both precipitates in terms of their size and density was observed to have a significant effect on the mechanical properties of the alloy

Modelling the effect of coating on the stresses and microstructure evolution in chill casting of wind turbine main shafts

DEFF Research Database (Denmark)

Sonne, Mads Rostgaard; Thorborg, J.; Hattel, Jesper Henri

2017-01-01

The purpose of the present work is to quantify the effect of the inside coating on chills for casting of large wind turbine main shafts with respect to the evolution of internal stresses. These are known to affect the lifetime of the chills, and this is a major cost for the foundries today. Simul......, it is concluded that the material quality obtained from casting the main shafts in chills (and hence the performance of the part) is still much better than for sand casting, even though a very thick layer of coating is applied. Copyright © 2017 John Wiley & Sons, Ltd....... in the simulations. The outcome is validated by comparisons with samples taken out from a critical region of main shafts cast in sand and in chills. The results reveal minor reductions in the maximum principal stresses on the inner and outer surfaces of the chill of 3.1% and 18.5%, respectively, from changing...

Molds in the Environment

Science.gov (United States)

... on Facebook Tweet Share Compartir Molds in the Environment What are molds? What are some of the ... molds found? Molds are found in virtually every environment and can be detected, both indoors and outdoors, ...

Study on quality control measures of static casting main pipe in PWR nuclear power plant

International Nuclear Information System (INIS)

Jiang Zhenbiao; Li Guanying; Liu Zhicheng

2013-01-01

This study analyzes the main reasons which impact the quality of primary pipe static casting elbows in PWR-M310 nuclear power plant. The quality control measures are developed from the election and inspection of material, improving sand production and casting process, improving lean management of personnel. The static casting defects of primary pipe elbows for Fuqing Unit 1 and 2 were down to less than 50% of the former project. The quality of static casting for the primary pipe elbows was significantly improved. Moreover, the implementation saves human resources and financing to repair casting defects, and also helps to win the delivery schedule. The quality control measures are good reference for improving primary pipe casting process. This study provides valuable experience for further study of improving the quality of static casting for the primary pipe of PWR nuclear power plant. (authors)

[Comparison of surface light scattering of acrylic intraocular lenses made by lathe-cutting and cast-molding methods--long-term observation and experimental study].

Science.gov (United States)

Nishihara, Hitoshi; Ayaki, Masahiko; Watanabe, Tomiko; Ohnishi, Takeo; Kageyama, Toshiyuki; Yaguchi, Shigeo

2004-03-01

To compare the long-term clinical and experimental results of soft acrylic intraocular lenses(IOLs) manufactured by the lathe-cut(LC) method and by the cast-molding(CM) method. This was a retrospective study of 20 patients(22 eyes) who were examined in a 5- and 7-year follow-up study. Sixteen eyes were implanted with polyacrylic IOLs manufactured by the LC method and 6 eyes were implanted with polyacrylic IOLs manufactured by the CM method. Postoperative measurements included best corrected visual acuity, contrast sensitivity, biomicroscopic examination, and Scheimpflug slit-lamp images to evaluate surface light scattering. Scanning electron microscopy and three-dimensional surface analysis were conducted. At 7 years, the mean visual acuity was 1.08 +/- 0.24 (mean +/- standard deviation) in the LC group and 1.22 +/- 0.27 in the CM group. Surface light-seatter was 12.0 +/- 4.0 computer compatible tapes(CCT) in the LC group and 37.4 +/- 5.4 CCT in the CM group. Mean surface roughness was 0.70 +/- 0.07 nm in the LC group and 6.16 +/- 0.97 nm in the CM group. Acrylic IOLs manufactured by the LC method are more stable in long-termuse.

Production and characterization of cast aluminum sponges

International Nuclear Information System (INIS)

Rivarola, M.E; Marmo Lupano, J.M; Malachevsky, M.T

2004-01-01

Cellular materials have unique physical features that make them particularly appropriate for applications that require high mechanical resistance and low weight. They can be produced in different ways: by powder metallurgy, by infiltration over plastic foams, adding a releasing agent of gas to a fused metal or simply injecting gas into it. Cellular structures can also be formed by casting onto a pore forming material. This work proposes a method that is basically similar to the last one mentioned but that allows the resulting material's porosity and topology to be controlled. Thus, the mechanical or thermal features of the material that is being manufactured can be predicted and/or designed. First the three dimensional print of a mold is made in a 3D printer, which is the negative of the piece that will be produced. Then a vacuum assisted aluminum cast is made. A preliminary study is presented for the applicability of this method and the mechanical properties of the resulting sponges (CW)

Zr O2-Y2 O3 ceramic bodies forming by slip casting

International Nuclear Information System (INIS)

Menezes, Cristiane A.B. de; Menezes, Fernanda; Ussui, Valter; Lazar, Dolores R.R.; Paschoal, Jose Otavio A.

1996-01-01

Slip casting technique of 3 mol% yttria stabilized zirconia powders suspensions has been used for ceramic bodies forming. The powders were produced by coprecipitation process with ammonium hydroxide in the Zirconium Pilot Plant of IPEN (Institute for Energy and Nuclear Researches, Sao Paulo, SP, (Brazil). Experiments were performed by preparing suspensions of powders with dispersing agents. These suspensions were submitted to milling and casting in plaster molds. After drying and heating at 700 deg C, the obtained specimens were sintered at 1500 deg C for 3 hours. The ceramic bodies were investigated by scanning electron microscopy and X-ray diffraction, and tested in high temperature conditions. (author)

Phenolic Molding Compounds

Science.gov (United States)

Koizumi, Koji; Charles, Ted; de Keyser, Hendrik

Phenolic Molding Compounds continue to exhibit well balanced properties such as heat resistance, chemical resistance, dimensional stability, and creep resistance. They are widely applied in electrical, appliance, small engine, commutator, and automotive applications. As the focus of the automotive industry is weight reduction for greater fuel efficiency, phenolic molding compounds become appealing alternatives to metals. Current market volumes and trends, formulation components and its impact on properties, and a review of common manufacturing methods are presented. Molding processes as well as unique advanced techniques such as high temperature molding, live sprue, and injection/compression technique provide additional benefits in improving the performance characterisitics of phenolic molding compounds. Of special interest are descriptions of some of the latest innovations in automotive components, such as the phenolic intake manifold and valve block for dual clutch transmissions. The chapter also characterizes the most recent developments in new materials, including long glass phenolic molding compounds and carbon fiber reinforced phenolic molding compounds exhibiting a 10-20-fold increase in Charpy impact strength when compared to short fiber filled materials. The role of fatigue testing and fatigue fracture behavior presents some insight into long-term reliability and durability of glass-filled phenolic molding compounds. A section on new technology outlines the important factors to consider in modeling phenolic parts by finite element analysis and flow simulation.

Assessment of harmfulness of green sand with additions of dust from dry dedusting

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M. Holtzer

2010-07-01

Full Text Available Recently, in the literature about the problems cause to the environment by foundry industry, attention has been paid to the presence and harmful effect of aromatic hydrocarbons: benzene, toluene, ethylbenzene and isomers of xylenes (BTEX and polycyclic aromatic hydrocarbons (PAHs. The growing interest in these pollutants of the environment is a result of their biological activity; some of them are characterized by mutagenic and carcinogenic action. In foundries these hydrocarbons are emitted during the contact between mould or core sands and liquid metal.This article discusses the results of the studies made on the elution rate of some harmful compounds include polycyclic aromatic hydrocarbons (PAHs (Table 3 and 4 from waste mould sand with bentonite and coal dust M1 (mixture Kormix 75 and this one with addition of dust from dry dedusting of sand M2 preparing station (partial replacement of bentonite and emission of BTEX gases from this moulds poured with molten cast iron. From the results given in these tables it follows that both mould sands are characterized by low values of the concentration of investigation substances and haven’t negative influence for environment during casting or management in other means. Tests were done according to the methodology developed at Faculty of Foundry Engineering University of Science and Technology in Cracow.

Investigation of friction and wear characteristics of cast iron material under various conditions

Energy Technology Data Exchange (ETDEWEB)

Joo, Ji Hoon; Kim, Chang Lae; Oh, Jeong Taek; Kim, Dae Eun [Yonsei University, Seoul (Korea, Republic of); Nemati, Narguess [School of Materials and Metallurgy, University of Tehran, Tehran (Iran, Islamic Republic of)

2015-08-15

Cast iron is widely used in fields such as the transport and heavy industries. For parts where contact damage is expected to occur, it is necessary to understand the friction and wear characteristics of cast iron. In this study, we use cast iron plates as the specimens to investigate their friction and wear characteristics. We perform various experiments using a reciprocating type tribotester. We assess the frictional characteristics by analyzing the friction coefficient values that were obtained during the sliding tests. We observe the wear surfaces of cast iron and steel balls using a scanning electron microscope, confocal microscope, and 3D profiler. We investigate the friction and wear characteristics of cast iron by injecting sand and alumina particles having various sizes. Furthermore, we estimate the effect of temperature on the friction and wear characteristics. The results obtained are expected to aid in the understanding of the tribological characteristics of cast iron in industry.

Investigation of gating parameter, temperature and density effects on mold filling in the lost foam casting (LFC process by direct observation method

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A. Sharifi

2013-03-01

Full Text Available Mold filling sequence of A356 aluminum alloy was investigated with the aid of direct observation method (photography method. The results show that increase of the foam density causes decrease of the filling rate and increase of the filling time. Foam density has more pronounced effect on mold filling rate rather than pouring temperature. Gating design also affects the profile of molten metal advancement in the mold. The results show that the higher filling rate was obtained with G2 gating than with other gating system. Regarding the mold filling pattern, G3 gating system has more effective contact interface than G2 gating system and has lower filling time. Filling time in G4 gating and G1 gating system are nearly the same.

Properties of experimental titanium cast investment mixing with water reducing agent solution.

Science.gov (United States)

Zhang, Zutai; Ding, Ning; Tamaki, Yukimichi; Hotta, Yasuhiro; Han-Cheol, Cho; Miyazaki, Takashi

2012-01-01

This study aimed to develop a dental investment for titanium casting. ZrO(2) and Al(2)O(3) were selected as refractory materials to prepare three investments (Codes: A-C) according to the quantity of Zr. Al(2)O(3) cement was used as a binder at a ratio of 15%, they were mixed with special mixing liquid. B1 was used as a control mixed with water. Fundamental examinations were statistically evaluated. A casting test was performed with investment B. Fluidities, setting times, and green strengths showed no remarkable differences; however, they were significantly different from those of B1. Expansion values for A, B, C, and B1 at 850°C were 1.03%±0.08%, 1.96%±0.17%, 4.35%±0.23%, and 1.50%±0.28%, respectively. Castings were covered by only small amounts of mold materials. The hardness test showed no significant differences between castings from B and the ones from commercial investments. The experimental special mixing liquid effectively reduced the water/powder ratio and improved the strength and thermal expansion.

Transferability of glass lens molding

Science.gov (United States)

Katsuki, Masahide

2006-02-01

Sphere lenses have been used for long time. But it is well known that sphere lenses theoretically have spherical aberration, coma and so on. And, aspheric lenses attract attention recently. Plastic lenses are molded easily with injection machines, and are relatively low cost. They are suitable for mass production. On the other hand, glass lenses have several excellent features such as high refractive index, heat resistance and so on. Many aspheric glass lenses came to be used for the latest digital camera and mobile phone camera module. It is very difficult to produce aspheric glass lenses by conventional process of curve generating and polishing. For the solution of this problem, Glass Molding Machine was developed and is spreading through the market. High precision mold is necessary to mold glass lenses with Glass Molding Machine. The mold core is ground or turned by high precision NC aspheric generator. To obtain higher transferability of the mold core, the function of the molding machine and the conditions of molding are very important. But because of high molding temperature, there are factors of thermal expansion and contraction of the mold and glass material. And it is hard to avoid the factors. In this session, I introduce following items. [1] Technology of glass molding and the machine is introduced. [2] The transferability of glass molding is analyzed with some data of glass lenses molded. [3] Compensation of molding shape error is discussed with examples.

Resistant metatarsus adductus: prospective randomized trial of casting versus orthosis.

Science.gov (United States)

Herzenberg, John E; Burghardt, Rolf D

2014-03-01

Metatarsus adductus is a common pediatric foot deformity related to intrauterine molding. It is usually a mild deformity that responds well to simple observation or minimal treatment with a home program of stretching. Resistant cases may need a more aggressive approach such as serial casting or special bracing to avoid the need for surgical intervention. We compared clinical outcomes using serial casting with orthoses for resistant metatarsus adductus. We prospectively treated 27 infants (43 feet) between the ages 3 and 9 months who failed home stretching treatment. Patients were randomized to either serial plaster casting or Bebax orthoses. Footprints and simulated weight-bearing anteroposterior and lateral view radiographs were made at entry and follow-up. There was no statistical difference between casting and Bebax for the following parameters: age at study entry, length of treatment, number of clinic visits, follow-up, and follow-up maintenance treatments. Both groups showed improvement in footprint and radiographic measurements post-treatment, without worsening of heel valgus. The Bebax group had greater improvement in the footprint heel bisector measurement than the casting group. The Bebax treatment requires more active parental cooperation. A simulated cost analysis of materials and office visit charges, however, revealed that Bebax treatment was significantly less expensive, about half the cost of casting. Because of the cost savings and virtually identical clinical results, we recommend the Bebax orthosis for resistant metatarsus in pre-walking infants with parents who are compliant. Other considerations include specific insurance plans, which may pay for casts but not orthoses.

Stress analysis of biomass fuel molding machine piston type stamping forming cone

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Wu Gaofeng

2015-01-01

Full Text Available It is established the ram biomass straw machine as the analysis object in this paper,the molding machine cones of stress in the forming process of the analysis of the system. We used pottery instead of Wear-resistant cast iron for improving the performance of forming sleeve. The structure of the forming sleeve was analyzed with the mechanical module of a soft named Pro/engineer in this paper. The result indicated that the program was feasible. With the sensitivity analysis we identified the suitable angle for the sleeve.

Metal Injection Molding (MIM of Magnesium and Its Alloys

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Martin Wolff

2016-05-01

Full Text Available Current research has highlighted that magnesium and its alloys as biodegradable material are highly suitable for biomedical applications. The new material fully degrades into nontoxic elements and offers material properties matching those of human bone tissue. As biomedical implants are rather small and complex in shape, the metal injection molding (MIM technique seems to be well suited for the near net shape mass production of such parts. Furthermore, MIM of Mg-alloys is of high interest in further technical fields. This study focusses on the performance of MIM-processing of magnesium alloy powders. It includes Mg-specific development of powder blending, feedstock preparation, injection molding, solvent and thermal debinding and final sintering. Even though Mg is a highly oxygen-affine material forming a stable oxide layer on each particle surface, the material can be sintered to nearly dense parts, providing mechanical properties matching those of as cast material. An ultimate tensile strength of 142 MPa, yield strength of 67 MPa, elastic modulus of 40 GPa and 8% elongation at fracture could be achieved using novel organic polymer binders for the feedstock preparation. Thus, first implant demonstrator parts could be successfully produced by the MIM technique.

Resource-saving technology for manufacturing billets for piston’s rings

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A. N. Krutilin

2010-10-01

Full Text Available Piston’s rings are one of the most critical parts of heavy-duty engines for wear-work in conditions of prolonged exposure of alternating loads and high temperatures. Currently in the world production of billets for piston’s rings is dominated by the two methods of casting: production of individual and oiling billets of gray and ductile cast iron in green-sand mold and shell mold and centrifugal casting method (intended primarily for oiling billets of ductile iron; the technology for individual production billets for piston’s rings with a diameter up to 250 mm, from 250 to 450 mm with individual and oiling ways, over 450 mm - preference of oiling billet. The best parameters of physical-mechanical and operational characteristics piston’s rings are in the case of manufacture of billets to the maximum extent approaching the configuration to the finished product. The rings made of shaped billets are characterized by uniform distribution of properties from the perimeter, provide a given diagram of pressures and full fit to the cylinder. Because of deficiencies of traditional methods of casting, continuous quality requirements for billets, the need for economy of material, fuel and energy resources, are finding new progressive technological processes of production of high-quality billets for piston’s rings. One of the most promising for piston rings billet is a method of casting consists of immersing the sand molds into the melt. It is interesting idea, expressed by A. Sutherland and subsequently patented in several countries in the way of casting method, called "immersion pouring technology" (ICT-Immersion Casting Technique [1]. Experiments, conducted in the laboratory of the Belarusian National Technical University, have identified significant shortcomings of immersion method of casting. When forms are immersing, have an intensive gassing in molten metal, and freezing of the metal on the out surface of the form. But despite some

Chemorheology of in-mold coating for compression molded SMC applications

Science.gov (United States)

Ko, Seunghyun; Straus, Elliott J.; Castro, Jose M.

2015-05-01

In-mold coating (IMC) is applied to compression molded sheet molding compound (SMC) exterior automotive or truck body panels as an environmentally friendly alternative to make the surface conductive for subsequent electrostatic painting operations. The coating is a thermosetting liquid that when injected onto the surface of the part cures and bonds to provide a smooth conductive surface. In order to optimize the IMC process, it is essential to predict the time available for flow, that is the time before the thermosetting reaction starts (inhibition time) as well as the time when the coating has enough structural integrity so that the mold can be opened without damaging the part surface (cure time). To predict both the inhibition time and the cure time, it is critical to study the chemorheology of IMC. In this paper, we study the chemorheology for a typical commercial IMC system, and show its relevance to both the flow and cure time for the IMC stage during SMC compression molding.

Thermal Stress of Surface of Mold Cavities and Parting Line of Silicone Molds

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Bajčičák Martin

2014-06-01

Full Text Available The paper is focused on the study of thermal stress of surface of mold cavities and parting line of silicone molds after pouring. The silicone mold White SD - THT was thermally stressed by pouring of ZnAl4Cu3 zinc alloy with pouring cycle 20, 30 and 40 seconds. The most thermally stressed part of surface at each pouring cycle is gating system and mold cavities. It could be further concluded that linear increase of the pouring cycle time leads to the exponential increasing of the maximum temperature of mold surface after its cooling. The elongated pouring cycle increases the temperature accumulated on the surface of cavities and the ability of silicone mold to conduct the heat on its surface decreases, because the low thermal conductivity of silicone molds enables the conduction of larger amount of heat into ambient environment.

The Through Process Simulation of Mold filling, Solidification, and Heat Treatment of the Al Alloy Bending Beam Low-pressure Casting

International Nuclear Information System (INIS)

Yin, Yajun; Guo, Zhao; Wang, Huan; Liao, Dunming; Chen, Tao; Zhou, Jianxin

2015-01-01

The research on the simulation for the through process of low-pressure casting and heat treatment is conducive to combine information technology and advanced casting technology, which will help to predict the defects and mechanical properties of the castings in the through process. In this paper, we focus on the simulation for through process of low-pressure casting and heat treatment of ZL114A Bending beam. Firstly, we analyzethe distribution of the shrinkage and porosities in filling and solidification process, and simulate the distribution of stress and strain in the late solidification of casting. Then, the numerical simulation of heat treatment process for ZL114A Bending beam is realized according to the heat treatment parameters and the corresponding simulation results of temperature field, stress, strain, and aging performance are given. Finally, we verify that simulation platform for the through process of low-pressure casting and heat treatment can serve the production practice perfectly and provide technical guidance and process optimization for the through process of low-pressure casting and heat treatment. (paper)

Experimental and Numerical Modeling of Fluid Flow Processes in Continuous Casting: Results from the LIMMCAST-Project

Science.gov (United States)

Timmel, K.; Kratzsch, C.; Asad, A.; Schurmann, D.; Schwarze, R.; Eckert, S.

2017-07-01

The present paper reports about numerical simulations and model experiments concerned with the fluid flow in the continuous casting process of steel. This work was carried out in the LIMMCAST project in the framework of the Helmholtz alliance LIMTECH. A brief description of the LIMMCAST facilities used for the experimental modeling at HZDR is given here. Ultrasonic and inductive techniques and the X-ray radioscopy were employed for flow measurements or visualizations of two-phase flow regimes occurring in the submerged entry nozzle and the mold. Corresponding numerical simulations were performed at TUBAF taking into account the dimensions and properties of the model experiments. Numerical models were successfully validated using the experimental data base. The reasonable and in many cases excellent agreement of numerical with experimental data allows to extrapolate the models to real casting configurations. Exemplary results will be presented here showing the effect of electromagnetic brakes or electromagnetic stirrers on the flow in the mold or illustrating the properties of two-phase flows resulting from an Ar injection through the stopper rod.

Rapid prototyping of a complex model for the manufacture of plaster molds for slip casting ceramic

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D. P. C. Velazco

2014-12-01

Full Text Available Computer assisted designing (CAD is well known for several decades and employed for ceramic manufacturing almost since the beginning, but usually employed in the first part of the projectual ideation processes, neither in the prototyping nor in the manufacturing stages. The rapid prototyping machines, also known as 3D printers, have the capacity to produce in a few hours real pieces using plastic materials of high resistance, with great precision and similarity with respect to the original, based on unprecedented digital models produced by means of modeling with specific design software or from the digitalization of existing parts using the so-called 3D scanners. The main objective of the work is to develop the methodology used in the entire process of building a part in ceramics from the interrelationship between traditional techniques and new technologies for the manufacture of prototypes. And to take advantage of the benefits that allow us this new reproduction technology. The experience was based on the generation of a complex piece, in digital format, which served as the model. A regular 15 cm icosahedron presented features complex enough not to advise the production of the model by means of the traditional techniques of ceramics (manual or mechanical. From this digital model, a plaster mold was made in the traditional way in order to slip cast clay based slurries, freely dried in air and fired and glazed in the traditional way. This experience has shown the working hypothesis and opens up the possibility of new lines of work to academic and technological levels that will be explored in the near future. This technology provides a wide range of options to address the formal aspect of a part to be performed for the field of design, architecture, industrial design, the traditional pottery, ceramic art, etc., which allow you to amplify the formal possibilities, save time and therefore costs when drafting the necessary and appropriate matrixes

Hydrogen silsesquioxane mold coatings for improved replication of nanopatterns by injection molding

DEFF Research Database (Denmark)

Hobæk, Thor Christian; Matschuk, Maria; Kafka, Jan

2015-01-01

of replication, thus allowing more time to fill the nanoscale cavities compared to standard metal molds. A monolayer of a fluorinated silane (heptadecafluorotrichlorosilane) deposited on the mold surface reduces the mold/polymer interfacial energy to support demolding of the polymer replica. The mechanical...

Investigations of the Influence of the Matrix Recycling on Properties of the Moulding Sand with Geopol 618 Binder

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J. Kamińska

2013-01-01

Full Text Available Self-hardening moulding sands with water-glass hardened by liquid esters are applied in several foundry plants for making moulds for the production of heavy iron and steel castings. The main good point of this process is a low cost of sands. However, on account of a lowsusceptibility of this moulding sand for the matrix reclamation the fraction of sands originated from the reclamation is limited.The investigations presented in this work were aimed at the determination of the addition of the reclaimed material, obtained in the dry mechanical reclamation, on properties of the moulding sand with the Geopol 618 binder, which is water-glass modified by polymers and hardened by esters.

Investigations of the Influence of the Matrix Recycling on Properties of the Moulding Sand with Geopol 618 Binder

Directory of Open Access Journals (Sweden)

Kamińska J.

2013-03-01

Full Text Available Self-hardening moulding sands with water-glass hardened by liquid esters are applied in several foundry plants for making moulds for the production of heavy iron and steel castings. The main good point of this process is a low cost of sands. However, on account of a low susceptibility of this moulding sand for the matrix reclamation the fraction of sands originated from the reclamation is limited. The investigations presented in this work were aimed at the determination of the addition of the reclaimed material, obtained in the dry mechanical reclamation, on properties of the moulding sand with the Geopol 618 binder, which is water-glass modified by polymers and hardened by esters.

Study of the Mechanism of Liquid Slag Infiltration for Lubrication in Slab Continuous Casting

Science.gov (United States)

Zhang, Shaoda; Wang, Qiangqiang; He, Shengping; Wang, Qian

2018-04-01

Consistent and uniform lubrication of the solidifying shell, especially in the meniscus, is crucial for the smooth continuous casting operation and production of strands free of surface defects. Thus, the current study established a coupled model to study the inflow behavior of liquid slag to the mold-strand channel, taking the solidification of steel and slag and the periodic oscillation of mold into account. The difficulties and solutions for the simulation were described in detail. The predicted profiles of the slag rim and initial shell were in good agreement with the reports. The main results indicated that liquid slag could be squeezed out and back into the slag pool in a negative strip period while a large amount of liquid slag could infiltrate into the mold-strand channel. Thus, the amount of slag consumed in the negative strip period was relatively small compared with that in the positive strip period. The predicted variation of slag consumption during mold oscillation was periodic, and the average value was 0.274 kg/m2, which agreed well with the slag consumption in industrial practice. The current model can predict and optimize the oscillation parameters aiming at stable lubrication conditions.

Environmental characterization foundry sands used in sanitary landfills

International Nuclear Information System (INIS)

Domingues, L.G.F.; Ferreira, G.C.S.; Pires, M.S.G.; Teixeira, I.; Carnin, R.; Sarro, W.S.

2016-01-01

The national solid waste policy recommends reducing solid waste generation and reusing them in different applications. Preliminary studies show that the foundry sand generated from cast metal parts undercut, has excellent applicability in grain size stabilization of soils for geotechnical functions, and therefore, should not be discarded as waste. This study aimed at environmental characterization of two lots of waste foundry sand (WFS), from different industries, to the particle size stabilization of a clayey soil for use in coverage of solid waste in landfills. The methodology included physicochemical characterization tests (grain size, permeability, XRF and heavy metals) and environmental (NBR 10004: 2004, NBR 10005: 2004, NBR 10006: 20004 and acute toxicity with Vibrio fischeri). The results prove the environmental viability of using these lots of WFS as functional material in the composition of landfills. (author)

Interactive Mold House Tour

Science.gov (United States)

Get a quick glimpse of some of the most important ways to protect your home from mold by this interactive tour of the Mold House. Room-by-room, you'll learn about common mold issues and how to address them.

Study of strength of Dsub(y)150 gate valve case, manufactured by centrifugal casting

International Nuclear Information System (INIS)

Umanskaya, L.G.; Semenov, P.V.; Tinyakov, V.G.; Babkina, R.I.; Khatuntsev, Eh.V.

1982-01-01

A process for manufacturing centrifugal-cast gate valve body is developed. Structural strength of such items, homogeneity, ductile and strength properties over the cross section as well as the metal susceptibility to embrittlement have been investigated. Three cast gate valve bodies have been taken: one - of 20GSL steel - for hydraulic testing, and two - of 15Kh1MFL steel - for investigation into the metal properties across the valve thickness. The strength properties of the centrifugal-cast gate valve body of 15Kh1M1FL steel are stated to meet the specifications. The gate valve metal ductility (delta and PSI) is twice as high as that of a sand-cast valve. The microstructure, strength and ductility are uniform both over wall thickness and over different body cross sections

A Comparative Study on Permanent Mold Cast and Powder Thixoforming 6061 Aluminum Alloy and Sicp/6061Al Composite: Microstructures and Mechanical Properties

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Xuezheng Zhang

2016-05-01

Full Text Available Microstructural and mechanical characterization of 10 vol% SiC particles (SiCp reinforced 6061 Al-based composite fabricated by powder thixoforming (PTF was investigated in comparison with the PTF and permanent mold cast (PMC 6061 monolithic alloys. The results reveal that the microstructure of the PMC alloy consists of coarse and equiaxed α dendrites and interdendritic net-like eutectic phases. However, the microstructure of the PTF composite, similar to that of the PTF alloy, consists of near-spheroidal primary particles and intergranular secondarily solidified structures except SiCp, which are distributed in the secondarily solidified structures. The eutectics amount in the PTF materials is distinctly lower than that in the PMC alloy, and the microstructures of the former materials are quite compact while that of the latter alloy is porous. Therefore, the PTF alloy shows better tensile properties than the PMC alloy. Owing to the existence of the SiC reinforcing particles, the PTF composite attains an ultimate tensile strength and yield strength of 230 MPa and 128 MPa, representing an enhancement of 27.8% and 29.3% than those (180 MPa and 99 MPa of the PTF alloy. A modified model based on three strengthening mechanisms was proposed to calculate the yield strength of the PTF composite. The obtained theoretical results were quite consistent with the experimental data.

A Comparative Study on Permanent Mold Cast and Powder Thixoforming 6061 Aluminum Alloy and Sicp/6061Al Composite: Microstructures and Mechanical Properties.

Science.gov (United States)

Zhang, Xuezheng; Chen, Tijun; Qin, He; Wang, Chong

2016-05-24

Microstructural and mechanical characterization of 10 vol% SiC particles (SiC p ) reinforced 6061 Al-based composite fabricated by powder thixoforming (PTF) was investigated in comparison with the PTF and permanent mold cast (PMC) 6061 monolithic alloys. The results reveal that the microstructure of the PMC alloy consists of coarse and equiaxed α dendrites and interdendritic net-like eutectic phases. However, the microstructure of the PTF composite, similar to that of the PTF alloy, consists of near-spheroidal primary particles and intergranular secondarily solidified structures except SiC p , which are distributed in the secondarily solidified structures. The eutectics amount in the PTF materials is distinctly lower than that in the PMC alloy, and the microstructures of the former materials are quite compact while that of the latter alloy is porous. Therefore, the PTF alloy shows better tensile properties than the PMC alloy. Owing to the existence of the SiC reinforcing particles, the PTF composite attains an ultimate tensile strength and yield strength of 230 MPa and 128 MPa, representing an enhancement of 27.8% and 29.3% than those (180 MPa and 99 MPa) of the PTF alloy. A modified model based on three strengthening mechanisms was proposed to calculate the yield strength of the PTF composite. The obtained theoretical results were quite consistent with the experimental data.

Freckle Defect Formation near the Casting Interfaces of Directionally Solidified Superalloys.

Science.gov (United States)

Hong, Jianping; Ma, Dexin; Wang, Jun; Wang, Fu; Sun, Baode; Dong, Anping; Li, Fei; Bührig-Polaczek, Andreas

2016-11-16

Freckle defects usually appear on the surface of castings and industrial ingots during the directional solidification process and most of them are located near the interface between the shell mold and superalloys. Ceramic cores create more interfaces in the directionally solidified (DS) and single crystal (SX) hollow turbine blades. In order to investigate the location of freckle occurrence in superalloys, superalloy CM247 LC was directionally solidified in an industrial-sized Bridgman furnace. Instead of ceramic cores, Alumina tubes were used inside of the casting specimens. It was found that freckles occur not only on the casting external surfaces, but also appear near the internal interfaces between the ceramic core and superalloys. Meanwhile, the size, initial position, and area of freckle were investigated in various diameters of the specimens. The initial position of the freckle chain reduces when the diameter of the rods increase. Freckle area follows a linear relationship in various diameters and the average freckle fraction is 1.1% of cross sectional area of casting specimens. The flow of liquid metal near the interfaces was stronger than that in the interdendritic region in the mushy zone, and explained why freckle tends to occur on the outer or inner surfaces of castings. This new phenomenon suggests that freckles are more likely to occur on the outer or inner surfaces of the hollow turbine blades.

Freckle Defect Formation near the Casting Interfaces of Directionally Solidified Superalloys

Directory of Open Access Journals (Sweden)

Jianping Hong

2016-11-01

Full Text Available Freckle defects usually appear on the surface of castings and industrial ingots during the directional solidification process and most of them are located near the interface between the shell mold and superalloys. Ceramic cores create more interfaces in the directionally solidified (DS and single crystal (SX hollow turbine blades. In order to investigate the location of freckle occurrence in superalloys, superalloy CM247 LC was directionally solidified in an industrial-sized Bridgman furnace. Instead of ceramic cores, Alumina tubes were used inside of the casting specimens. It was found that freckles occur not only on the casting external surfaces, but also appear near the internal interfaces between the ceramic core and superalloys. Meanwhile, the size, initial position, and area of freckle were investigated in various diameters of the specimens. The initial position of the freckle chain reduces when the diameter of the rods increase. Freckle area follows a linear relationship in various diameters and the average freckle fraction is 1.1% of cross sectional area of casting specimens. The flow of liquid metal near the interfaces was stronger than that in the interdendritic region in the mushy zone, and explained why freckle tends to occur on the outer or inner surfaces of castings. This new phenomenon suggests that freckles are more likely to occur on the outer or inner surfaces of the hollow turbine blades.

An easy mold

International Nuclear Information System (INIS)

Kim, Nam Hun; Choe, Jong Sun

1988-04-01

This book deals with an easy mold, which introduces what is a mold kinds and classification of mold. It gives descriptions of easy theories such as basic knowledge on shearing work, clearance, power for punching and shear angle, basic knowledge for bending such as transform by bending, the minimal bending radius, spring back, the length of material, flexural strength for bending, fundamental knowledge for drawing work with transform of drawing and limitation of drawing.

Using sol-gel component as additive to foundry coatings to improve casting quality

DEFF Research Database (Denmark)

Nwaogu, Ugochukwu Chibuzoh; Poulsen, T.; Gravesen, B.

2012-01-01

The improvement of foundry coatings to enhance performance is important. This paper investigates the effect of using sol‐gel component as an additive to foundry coatings applied on chemically bonded sand cores. Three parameters at three levels each were investigated using Taguchi experimental...... was evaluated. The results show that the surface quality of castings obtained by adding the sol‐gel component to the coatings for cold box cores has no significant difference from castings produced with coatings without sol‐gel component. On the other hand, the addition of the sol‐gel component in coatings...

Moulding Sands with New InorganicBinders - Ecology Assessment in the Aspect of Work Environment

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I. Szanda

2012-09-01

Full Text Available The development of economy and industry introducing new technologies and materials often means the increased threat of occurrenceof factors harmful to humans and environment. Workers employed in foundries as mould pourers are the group of high professional risk.Foundry moulding sands when poured with liquid metal are a source of the emission of harmful, toxic and carcinogenic (benzene,PAHs compounds.The paper presents the results of studies on the concentration of chemical compounds emitted in the process of casting aluminiumalloy and brass using moulding sands with the new inorganic binders. The specific values of the exposure indices were compared with thelimit values. This enabled an assessment of the impact of moulding sands on work environment. The obtained results were compared withthe values of contaminants emitted when pouring foundry moulds made from furan sands and bentonite sands with an addition of coaldust.Studies were carried out under the project POIG.01.01.02-00-015/09 "Advanced materials and technologies."

The role of aluminum distribution on the local corrosion resistance of the microstructure in a sand-cast AM50 alloy

International Nuclear Information System (INIS)

Danaie, Mohsen; Asmussen, Robert Matthew; Jakupi, Pellumb; Shoesmith, David W.; Botton, Gianluigi A.

2013-01-01

Highlights: •Site-specific analytical electron microscopy was performed on corroded AM50. •Areas close to eutectic microstructure show less corrosion damage. •Eutectic Mg grains develop an Al-rich layer between the alloy and corrosion product. •We demonstrate, using low-loss EELS, that the Al-rich layer is metallic in character. •Primary α-Mg grains, with lower Al content, do not develop the Al-rich layer and corrode severely. -- Abstract: Site-specific analytical electron microscopy was performed on a corroded sand-cast AM50 alloy. Areas close to partially divorced eutectic were the regions with less corrosion damage. The corrosion product layer in these areas consisted of a columnar section of predominantly amorphous MgO. At the alloy interface, an aluminum-rich layer was identified. Electron energy-loss spectroscopy suggests this layer is metallic in character. The corrosion product film on the primary α-Mg grains possessed a bi-layer morphology: a thin columnar film and a thicker, porous sub-layer. The formation of the Al-rich layer depends on the Al content in solid solution at a specific location

Mechanical Properties of Al-Si-Mg Alloy Castings as a Function of Structure Refinement and Porosity Fraction

Directory of Open Access Journals (Sweden)

Hajkowski M.

2012-12-01

Full Text Available During design of the casting products technology, an important issue is a possibility of prediction of mechanical properties resulting from the course of the casting solidification process. Frequently there is a need for relations describing mechanical properties of silumin alloys as a function of phase refinement in a structure and a porosity fraction, and relations describing phase refinement in the structure and the porosity fraction as a function of solidification conditions. The study was conducted on castings of a 22 mm thick plate, made of EN AC-AlSi7Mg0,3 alloy in moulds: of quartz sand, of quartz sand with chill and in permanent moulds. On the basis of cooling curves, values of cooling rate in various casting parts were calculated. The paper also presents results of examination of distance between arms in dendrites of a solid solution α (DASL, precipitations length of silicon in an eutectic (DlSi and gas-shrinkage porosity (Por as a function of cooling rate. Statistical relations of DASL, DlSi, Por as a function of cooling rate and statistical multiparameter dependencies describing mechanical properties (tensile strength, yield strength, elongation of alloy as a function of DASL, DlSi and Por are also presented in the paper.

Autonomous Optimization of a Solidification Pattern and Its Effect on Porosity and Segregation in Steel Castings

DEFF Research Database (Denmark)

Kotas, Petr; Tutum, Cem Celal; Hattel, Jesper Henri

2011-01-01

The present paper considers optimization of a solidification pattern of a gravity sand-cast steel part. That is, the choice of proper riser and chill designs has been investigated using genetic algorithms while simultaneously considering their impact on centerline porosity and macrosegregation...... distribution. This was accomplished by coupling a casting simulation software package with an optimization module. The casting process of the original casting design was simulated using a transient 3D thermal model incorporated in a commercial simulation software package to determine potential flaws...... and inadequacies. After this initial assessment, a new geometrical model was suggested with the redesigned gating system and rearranged chills to obtain better filling and solidification patterns. Based on the improved model, relevant optimization targets and constraints were defined. One multi...

The effect of annealing temperatures and cooling rates on microstructure and mechanical properties of investment cast Ti-6Al-4V alloy

International Nuclear Information System (INIS)

Jovanovic, M.T.; Tadic, S.; Zec, S.; Miskovic, Z.; Bobic, I.

2006-01-01

Production of investment castings of titanium alloys was considerably increased during last years due to the significant cost savings compared to complicated machined parts. However, the disadvantage of as-cast titanium alloys is that the heat-treatment remains only a limited option for improvement of their properties. The object of this paper was to study the effect of heat-treatment of investment cast Ti-6Al-4V alloy performing X-ray diffraction analysis, light microscopy and quantitative metallography together with hardness and room temperature tensile tests. The effect of annealing temperatures (above and below β transus temperature) and cooling rates on microstructure and mechanical properties was discussed in terms of the β → α transformation. The results of this paper also show that, besides heat treatment parameters, melting and casting practice together with mold technology strongly influence the properties of castings

Formation mechanism of spheroidal carbide in ultra-low carbon ductile cast iron

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Bin-guo Fu

2016-09-01

Full Text Available The formation mechanism of the spheroidal carbide in the ultra-low carbon ductile cast iron fabricated by the metal mold casting technique was systematically investigated. The results demonstrated that the spheroidal carbide belonged to eutectic carbide and crystallized in the isolated eutectic liquid phase area. The formation process of the spheroidal carbide was related to the contact and the intersection between the primary dendrite and the secondary dendrite of austenite. The oxides of magnesium, rare earths and other elements can act as heterogeneous nucleation sites for the spheroidal carbide. It was also found that the amount of the spheroidal carbide would increase with an increase in carbon content. The cooling rate has an important influence on the spheroidal carbide under the same chemical composition condition.

Hydrophobicity Tuning by the Fast Evolution of Mold Temperature during Injection Molding

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Sara Liparoti

2018-03-01

Full Text Available The surface topography of a molded part strongly affects its functional properties, such as hydrophobicity, cleaning capabilities, adhesion, biological defense and frictional resistance. In this paper, the possibility to tune and increase the hydrophobicity of a molded polymeric part was explored. An isotactic polypropylene was injection molded with fast cavity surface temperature evolutions, obtained adopting a specifically designed heating system layered below the cavity surface. The surface topology was characterized by atomic force microscopy (AFM and, concerning of hydrophobicity, by measuring the water static contact angle. Results show that the hydrophobicity increases with both the temperature level and the time the cavity surface temperature was kept high. In particular, the contact angle of the molded sample was found to increase from 90°, with conventional molding conditions, up to 113° with 160 °C of cavity surface temperature kept for 18 s. This increase was found to be due to the presence of sub-micro and nano-structures characterized by high values of spatial frequencies which could be more accurately replicated by adopting high heating temperatures and times. The surface topography and the hydrophobicity resulted therefore tunable by selecting appropriate injection molding conditions.

Grindability of dental cast Ti-Ag and Ti-Cu alloys.

Science.gov (United States)

Kikuchi, Masafumi; Takahashi, Masatoshi; Okabe, Toru; Okuno, Osamu

2003-06-01

Experimental Ti-Ag alloys (5, 10, and 20 mass% Ag) and Ti-Cu alloys (2, 5, and 10 mass% Cu) were cast into magnesia molds using a dental casting machine, and their grindability was investigated. At the lowest grinding speed (500 m min(-1)), there were no statistical differences among the grindability values of the titanium and titanium alloys. The grindability of the alloys increased as the grinding speed increased. At the highest grinding speed (1500 m x min(-1)), the grindability of the 20% Ag, 5% Cu, and 10% Cu alloys was significantly higher than that of titanium. It was found that alloying with silver or copper improved the grindability of titanium, particularly at a high speed. It appeared that the decrease in elongation caused by the precipitation of small amounts of intermetallic compounds primarily contributed to the favorable grindability of the experimental alloys.

Effecting aging time of epoxy molding compound to molding process for integrated circuit packaging

Science.gov (United States)

Tachapitunsuk, Jirayu; Ugsornrat, Kessararat; Srisuwitthanon, Warayoot; Thonglor, Panakamon

2017-09-01

This research studied about effecting aging time of epoxy molding compound (EMC) that effect to reliability performance of integrated circuit (IC) package in molding process. Molding process is so important of IC packaging process for protecting IC chip (or die) from temperature and humidity environment using encapsulated EMC. For general molding process, EMC are stored in the frozen at 5°C and left at room temperature at 25 °C for aging time on self before molding of die onto lead frame is 24 hours. The aging time effect to reliability performance of IC package due to different temperature and humidity inside the package. In experiment, aging time of EMC were varied from 0 to 24 hours for molding process of SOIC-8L packages. For analysis, these packages were tested by x-ray and scanning acoustic microscope to analyze properties of EMC with an aging time and also analyzed delamination, internal void, and wire sweep inside the packages with different aging time. The results revealed that different aging time of EMC effect to properties and reliability performance of molding process.

Effect of surface reaction layer on grindability of cast titanium alloys.

Science.gov (United States)

Ohkubo, Chikahiro; Hosoi, Toshio; Ford, J Phillip; Watanabe, Ikuya

2006-03-01

The purpose of this study was to investigate the effect of the cast surface reaction layer on the grindability of titanium alloys, including free-machining titanium alloy (DT2F), and to compare the results with the grindability of two dental casting alloys (gold and Co-Cr). All titanium specimens (pure Ti, Ti-6Al-4V and DT2F) were cast using a centrifugal casting machine in magnesia-based investment molds. Two specimen sizes were used to cast the titanium metals so that the larger castings would be the same size as the smaller gold and Co-Cr alloy specimens after removal of the surface reaction layer (alpha-case). Grindability was measured as volume loss ground from a specimen for 1 min using a handpiece engine with a SiC abrasive wheel at 0.1 kgf and four circumferential wheel speeds. For the titanium and gold alloys, grindability increased as the rotational speed increased. There was no statistical difference (p>0.05) in grindability for all titanium specimens either with or without the alpha-case. Of the titanium metals tested, Ti-6 Al-4V had the greatest grindability at higher speeds, followed by DT2F and CP Ti. The grindability of the gold alloy was similar to that of Ti-6 Al-4V, whereas the Co-Cr alloy had the lowest grindability. The results of this study indicated that the alpha-case did not significantly affect the grindability of the titanium alloys. The free-machining titanium alloy had improved grindability compared to CP Ti.

Prevention of burn-on defect on surface of hydroturbine blade casting of ultra-low-carbon refining stainless steel

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Li Ling

2008-08-01

Full Text Available The burn-on sand is common surface defect encountered in CO2-cured silicate-bonded sand casting of hydroturbine blade of ultra-low-carbon martensitic stainless steel, its feature, causes and prevention measures are presented in this paper. Experiments showed that the burn-on defect is caused by oxidization of chromium in the molten steel at high temperature and can be effectively eliminated by using chromium-corundum coating.

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

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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.

Effects of mold geometry on fiber orientation of powder injection molded metal matrix composites

Energy Technology Data Exchange (ETDEWEB)

Ahmad, Faiz, E-mail: faizahmad@petronas.com.my; Aslam, Muhammad, E-mail: klaira73@gmail.com; Altaf, Khurram, E-mail: khurram.altaf@petronas.com.my; Shirazi, Irfan, E-mail: irfanshirazi@hotmail.com [Mechanical Engineering Universiti Teknologi PETRONAS Malaysia (Malaysia)

2015-07-22

Fiber orientations in metal matrix composites have significant effect on improving tensile properties. Control of fiber orientations in metal injection molded metal composites is a difficult task. In this study, two mold cavities of dimensions 6x6x90 mm and 10x20x180 mm were used for comparison of fiber orientation in injection molded metal composites test parts. In both mold cavities, convergent and divergent flows were developed by modifying the sprue dimensions. Scanning electron microscope (SEM) was used to examine the fiber orientations within the test samples. The results showed highly aligned fiber in injection molded test bars developed from the convergent melt flow. Random orientation of fibers was noted in the composites test bars produced from divergent melt flow.

A Study of the Heat Transfer Behavior of Mold Fluxes with Different Amounts of Al2O3

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Lejun Zhou

2016-06-01

Full Text Available The element Al in molten aluminum containing steel reacts with the liquid mold flux and thus be transferred into the mold flux during the continuous casting process. Additionally, the increase in alumina in a mold flux changes its performance significantly. Thus, in this paper, the heat transfer properties of mold fluxes with the Al2O3 content ranging from 7 to 40 wt. % were studied with the Infrared Emitter Technique (IET. Results found that heat flux at the final steady state decreased from 423 kW·m−2 to 372 kW·m−2 with the increase in Al2O3 content from 7% to 30%, but it increased to 383 kW·m−2 when the Al2O3 content was further increased to 40%. Both crystalline layer thickness and crystalline fraction first increased, then decreased with the further addition of A2O3 content. Moreover, it indicated that the heat transfer process inside the mold was dominated by both a crystallization of mold flux and the resulting interfacial thermal resistance. Further, the Rint increased from 9.2 × 10−4 m2·kW−1 to 11.0 × 10−4 m2·kW−1 and then to 16.0 × 10−4 m2·kW−1 when the addition of Al2O3 content increased from 7% to 20% and then to 30%, respectively; however, it decreased to 13.6 × 10−4 m2·kW−1 when the Al2O3 content reached 40%.

Creating mold-free buildings: a key to avoiding health effects of indoor molds.

Science.gov (United States)

Small, Bruce M

2003-08-01

In view of the high costs of building diagnostics and repair subsequent to water damage--as well as the large medical diagnostic and healthcare costs associated with mold growth in buildings--commitment to a philosophy of proactive preventive maintenance for home, apartment, school, and commercial buildings could result in considerable cost savings and avoidance of major health problems among building occupants. The author identifies common causes of mold growth in buildings and summarizes key building design and construction principles essential for preventing mold contamination indoors. Physicians and healthcare workers must be made aware of conditions within buildings that can give rise to mold growth, and of resulting health problems. Timely advice provided to patients already sensitized by exposure to molds could save these individuals, and their families, from further exposures as a result of inadequate building maintenance or an inappropriate choice of replacement housing.

Gas-liquid Two Phase Flow Modelling of Incompressible Fluid and Experimental Validation Studies in Vertical Centrifugal Casting

International Nuclear Information System (INIS)

Zhou, J X; Shen, X; Yin, Y J; Guo, Z; Wang, H

2015-01-01

In this paper, Gas-liquid two phase flow mathematic models of incompressible fluid were proposed to explore the feature of fluid under certain centrifugal force in vertical centrifugal casting (VCC). Modified projection-level-set method was introduced to solve the mathematic models. To validate the simulation results, two methods were used in this study. In the first method, the simulation result of basic VCC flow process was compared with its analytic solution. The relationship between the numerical solution and deterministic analytic solution was presented to verify the correctness of numerical algorithms. In the second method, systematic water simulation experiments were developed. In this initial experiment, special experimental vertical centrifugal device and casting shapes were designed to describe typical mold-filling processes in VCC. High speed camera system and data collection devices were used to capture flow shape during the mold-filling process. Moreover, fluid characteristic at different rotation speed (from 40rpm, 60rpmand 80rpm) was discussed to provide comparative resource for simulation results. As compared with the simulation results, the proposed mathematical models could be proven and the experimental design could help us advance the accuracy of simulation and further studies for VCC. (paper)

Functional nanostructures on injection molded plastic

DEFF Research Database (Denmark)

Johansson, Alicia Charlotte; Søgaard, Emil; Andersen, Nis Korsgaard

Nanotechnology can be used to make inexpensive plastic parts with functional surfaces. The plastic parts can be molded using a standard injection molding process. The nanostructures are directly transferred from the surface of the molding tool to the surface of the molded plastic part during...

Development of casting investment preventing blackening of noble metal alloys Part 2. Application of developed investment for type 4 gold alloy.

Science.gov (United States)

Nakai, Akira; Kakuta, Kiyoshi; Goto, Shin-ichi; Kato, Katuma; Yara, Atushi; Ogura, Hideo

2003-09-01

The objective of this study was to evaluate the efficacy of the developed investment for the prevention of blackening of a cast Type 4 gold and to analyze the oxides on its surface in relation to the blackening of the alloy. The experimental investments were prepared using a gypsum-bonded investment in which boron (B) or aluminum (Al) was added as a reducing agent. A Type 4 gold alloy was cast into the mold made of the prepared investment. The effect of the additives was evaluated from the color difference (deltaE*) between the as-cast surface and the polished surface of the cast specimen. B and Al were effective to prevent the blackening of a Type 4 gold alloy and the color of the as-cast surface approached that of the polished surface with increasing B and Al content. The prevention of the blackening of the gold alloy can be achieved by restraining the formation of CuO.

Traditional Mold Analysis Compared to a DNA-based Method of Mold Analysis with Applications in Asthmatics' Homes

Science.gov (United States)

Traditional environmental mold analysis is based-on microscopic observations and counting of mold structures collected from the air on a sticky surface or culturing of molds on growth media for identification and quantification. A DNA-based method of mold analysis called mol...

Elasticity of Moulding Sands – a Method of Reducing Core Cracking

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Dobosz St. M.

2017-03-01

Full Text Available This paper focuses on mechanical properties of self hardening moulding sands with furfuryl and alkyd binders. Elasticity as a new parameter of moulding sands is investigated. With the use of presented testing equipment, it is possible to determine force kinetics and deformation of moulding sand in real time. The need for this kind of study comes from the modern casting industry. New foundries can be characterized with high intensity of production which is correlated with high level of mechanization and automatization of foundry processes. The increasingly common use of manipulators in production of moulds and cores can lead to generation of new types of flaws, caused by breakage in moulds and cores which could occur during mould assembly. Hence it is required that moulds and cores have high resistance to those kinds of factors, attributing it with the phenomenon of elasticity. The article describes the theoretical basis of this property, presents methods of measuring and continues earlier research.

Computer-aided injection molding system

Science.gov (United States)

Wang, K. K.; Shen, S. F.; Cohen, C.; Hieber, C. A.; Isayev, A. I.

1982-10-01

Achievements are reported in cavity-filling simulation, modeling viscoelastic effects, measuring and predicting frozen-in birefringence in molded parts, measuring residual stresses and associated mechanical properties of molded parts, and developing an interactive mold-assembly design program and an automatic NC maching data generation and verification program. The Cornell Injection Molding Program (CIMP) consortium is discussed as are computer user manuals that have been published by the consortium. Major tasks which should be addressed in future efforts are listed, including: (1) predict and experimentally determine the post-fillin behavior of thermoplastics; (2) simulate and experimentally investigate the injection molding of thermosets and filled materials; and (3) further investigate residual stresses, orientation and mechanical properties.

Wearing Quality of Austenitic, Duplex Cast Steel, Gray and Spheroidal Graphite Iron

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S. Pietrowski

2012-04-01

Full Text Available The current work presents the research results of abrasion wear and adhesive wear at rubbing and liquid friction of new austenitic, austenitic-ferritic (“duplex” cast steel and gray cast iron EN-GJL-250, spheroidal graphite iron EN-GJS-600-3, pearlitic with ledeburitic carbides and spheroidal graphite iron with ledeburitic carbides with a microstructure of the metal matrix: pearlitic, upper bainite, mixture of upper and lower bainite, martensitic with austenite, pearlitic-martensitic-bainitic-ausferritic obtained in the raw state. The wearing quality test was carried out on a specially designed and made bench. Resistance to abrasion wear was tested using sand paper P40. Resistance to adhesive wear was tested in interaction with steel C55 normalized, hardened and sulfonitrided. The liquid friction was obtained using CASTROL oil. It was stated that austenitic cast steel and “duplex” are characterized by a similar value of abrasion wear and adhesive wear at rubbing friction. The smallest decrease in mass was shown by the cast steel in interaction with the sulfonitrided steel C55. Austenitic cast steel and “duplex��� in different combinations of friction pairs have a higher wear quality than gray cast iron EN-GJL- 250 and spheroidal graphite iron EN-GJS-600-3. Austenitic cast steel and “duplex” are characterized by a lower wearing quality than the spheroidal graphite iron with bainitic-martensitic microstructure. In the adhesive wear test using CASTROL oil the tested cast steels and cast irons showed a small mass decrease within the range of 1÷2 mg.

Mechanical properties of chemically bonded sand core materials dipped in sol-gel coating impregnated with filter

DEFF Research Database (Denmark)

Nwaogu, Ugochukwu Chibuzoh; Tiedje, Niels Skat

2012-01-01

A novel sol-gel coating impregnated with filter dust was applied on chemically bonded sand core materials by dipping. After curing, the strengths of the core materials were measured under uniaxial loading using a new strength testing machine (STM). The STM presents the loading history as a force-...... of the chemically bonded sand core materials, a combination of flexural and compression tests is suggested for improving the casting quality. © 2012 W. S. Maney & Son Ltd.......A novel sol-gel coating impregnated with filter dust was applied on chemically bonded sand core materials by dipping. After curing, the strengths of the core materials were measured under uniaxial loading using a new strength testing machine (STM). The STM presents the loading history as a force...... the strengths were increased under compression. The mode of fracture of the chemically bonded sand core materials was observed to be intergranular through the binder. The stiffness of the chemically bonded sand core materials was determined. For better understanding of the mechanical properties...

Experimental investigation on high performance RC column with manufactured sand and silica fume

Science.gov (United States)

Shanmuga Priya, T.

2017-11-01

In recent years, the use High Performance Concrete (HPC) has increased in construction industry. The ingredients of HPC depend on the availability and characteristics of suitable alternative materials. Those alternative materials are silica fume and manufactured sand, a by products from ferro silicon and quarry industries respectively. HPC made with silica fume as partial replacement of cement and manufactured sand as replacement of natural sand is considered as sustainable high performance concrete. In this present study the concrete was designed to get target strength of 60 MPa as per guide lines given by ACI 211- 4R (2008). The laboratory study was carried out experimentally to analyse the axial behavior of reinforced cement HPC column of size 100×100×1000mm and square in cross section. 10% of silica fume was preferred over ordinary portland cement. The natural sand was replaced by 0, 20, 40, 60, 80 and 100% with Manufactured Sand (M-Sand). In this investigation, totally 6 column specimens were cast for mixes M1 to M6 and were tested in 1000kN loading frame at 28 days. From this, Load-Mid height deflection curves were drawn and compared. Maximum ultimate load carrying capacity and the least deflection is obtained for the mix prepared by partial replacement of cement with 10% silica fume & natural sand by 100% M-Sand. The fine, amorphous and pozzalonic nature of silica fume and fine mineral particles in M- Sand increased the stiffness of HPC column. The test results revealed that HPC can be produced by using M-Sand with silica fume.

Parameters of the Two-Phase Sand-Air Stream in the Blowing Process

Directory of Open Access Journals (Sweden)

Danko J.

2012-12-01

Full Text Available Theoretical problems concerning the determination of work parameters of the two-phase sand-air stream in the cores making process by blowing methods as well as experimental methods of determination of the main and auxiliary parameters of this process decisive on the cores quality assessed by the value and distribution of their apparent density are presented in the paper. In addition the results of visualisations of the core-box filling with the sand-air stream, from the blowing chamber, obtained by the process filming by means of the quick-action camera are presented in the paper and compared with the results of simulation calculations with the application of the ProCast software.

Parameters of the Two-Phase Sand-Air Stream in the Blowing Process

Directory of Open Access Journals (Sweden)

J. Danko

2012-12-01

Full Text Available Theoretical problems concerning the determination of work parameters of the two-phase sand-air stream in the cores making process byblowing methods as well as experimental methods of determination of the main and auxiliary parameters of this process decisive on thecores quality assessed by the value and distribution of their apparent density are presented in the paper. In addition the results of visualisations of the core-box filling with the sand-air stream, from the blowing chamber, obtained by the process filming by means of the quick-action camera are presented in the paper and compared with the results of simulation calculations with the application of the ProCast software.

Performance of molded plastic scintillators

International Nuclear Information System (INIS)

Gen, N.S.; Leman, V.E.; Solomonov, V.M.

1989-01-01

The performance of molded plastic scintillators is studied. The plastic scintillators studied were formed by transfer molding and intrusion from a scintillation composition consisting of polystyrene and a standard system of luminescent additives: 2 mass % of paraterphenyl + 0.06 mass % 1,4-di-/2-[5-phenyloxazoyly]/benzene and a plasticizer. The combined effect of mechanical load and temperature was studied. The effect of radiation on molded plastic scintillators was studied using gamma radiation from a 60 Co source. The studies show that the main operating characteristics of molded plastic scintillators are on a par with those of polymerized plastic scintillators. At the same time, molded plastic scintillators are superior in thermal stability at temperatures below the glass transition temperature and with respect to their working temperature range