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Sample records for semisolid metal processing

  1. Semisolid Metal Processing Consortium

    Energy Technology Data Exchange (ETDEWEB)

    Apelian,Diran

    2002-01-10

    Mathematical modeling and simulations of semisolid filling processes remains a critical issue in understanding and optimizing the process. Semisolid slurries are non-Newtonian materials that exhibit complex rheological behavior. There the way these slurries flow in cavities is very different from the way liquid in classical casting fills cavities. Actually filling in semisolid processing is often counter intuitive

  2. Trend and Development of Semisolid Metal Joining Processing

    Directory of Open Access Journals (Sweden)

    M. N. Mohammed

    2015-01-01

    Full Text Available The semisolid metal joining (SSMJ process or thixojoining process has recently been developed based on the principles of SSM processing, which is a technology that involves the formation of metal alloys between solidus and liquidus temperatures. Thixojoining has many potential benefits, which has encouraged researchers to carry out feasibility studies on various materials that could be utilized in this process and which could transform the production of metal components. This paper reviews the findings in the literature to date in this evolving field, specifically, the experimental details, technology considerations for industrialization, and advantages and disadvantages of the various types of SSMJ methods that have been proposed. It also presents details of the range of materials that have been joined by using the SSMJ process. Furthermore, it highlights the huge potential of this process and future directions for further research.

  3. T5 heat treatment of semi-solid metal processed aluminium alloy F357

    CSIR Research Space (South Africa)

    Moller, H

    2009-04-01

    Full Text Available The T5 heat treatment of semi-solid metal (SSM) processed alloy F357 was investigated by considering the effects of cooling rate and natural aging after casting, as well as artificial aging parameters on tensile properties. In addition, the tensile...

  4. Analysis of semi-solid processing for metal matrix composite synthesis using factorial design

    Directory of Open Access Journals (Sweden)

    Kratus Ranieri

    2012-02-01

    Full Text Available The main goal in this work is to conduct a quantitative analysis of the mechanical stir casting process for obtaining particulate metal matrix composites. A combined route of stirring at semi-solid state followed by stirring at liquid state is proposed. A fractional factorial design was developed to investigate the influence and interactions of factors as: time, rotation, initial fraction and particle size, on the incorporated fraction. The best incorporations were obtained with all factors at high levels, as well as that very long stirring periods have no strong influence being particle size and rotation the most important factors on the incorporated fraction. Particle wetting occurs during stirring at semi-solid state, highlighting the importance of the interactions between particles and the alloy globularized phase. The role of the alloying element Mg as a wettability-promoting agent is discussed. The shear forces resulting from the stirring system is emphasized and understood as the effect of rotation itself added to the propeller blade geometry.

  5. Fabrication of metal matrix composite by semi-solid powder processing

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Yufeng [Iowa State Univ., Ames, IA (United States)

    2011-01-01

    Various metal matrix composites (MMCs) are widely used in the automotive, aerospace and electrical industries due to their capability and flexibility in improving the mechanical, thermal and electrical properties of a component. However, current manufacturing technologies may suffer from insufficient process stability and reliability and inadequate economic efficiency and may not be able to satisfy the increasing demands placed on MMCs. Semi-solid powder processing (SPP), a technology that combines traditional powder metallurgy and semi-solid forming methods, has potential to produce MMCs with low cost and high efficiency. In this work, the analytical study and experimental investigation of SPP on the fabrication of MMCs were explored. An analytical model was developed to understand the deformation mechanism of the powder compact in the semi-solid state. The densification behavior of the Al6061 and SiC powder mixtures was investigated with different liquid fractions and SiC volume fractions. The limits of SPP were analyzed in terms of reinforcement phase loading and its impact on the composite microstructure. To explore adoption of new materials, carbon nanotube (CNT) was investigated as a reinforcing material in aluminum matrix using SPP. The process was successfully modeled for the mono-phase powder (Al6061) compaction and the density and density distribution were predicted. The deformation mechanism at low and high liquid fractions was discussed. In addition, the compaction behavior of the ceramic-metal powder mixture was understood, and the SiC loading limit was identified by parametric study. For the fabrication of CNT reinforced Al6061 composite, the mechanical alloying of Al6061-CNT powders was first investigated. A mathematical model was developed to predict the CNT length change during the mechanical alloying process. The effects of mechanical alloying time and processing temperature during SPP were studied on the mechanical, microstructural and

  6. Energy Saving Melting and Revert Reduction Technology: Innovative Semi-Solid Metal (SSM) Processing

    Energy Technology Data Exchange (ETDEWEB)

    Diran Apelian

    2012-08-15

    Semi-solid metal (SSM) processing has emerged as an attractive method for near-net-shape manufacturing due to the distinct advantages it holds over conventional near-net-shape forming technologies. These advantages include lower cycle time, increased die life, reduced porosity, reduced solidification shrinkage, improved mechanical properties, etc. SSM processing techniques can not only produce the complex dimensional details (e.g. thin-walled sections) associated with conventional high-pressure die castings, but also can produce high integrity castings currently attainable only with squeeze and low-pressure permanent mold casting processes. There are two primary semi-solid processing routes, (a) thixocasting and (b) rheocasting. In the thixocasting route, one starts from a non-dendritic solid precursor material that is specially prepared by a primary aluminum manufacturer, using continuous casting methods. Upon reheating this material into the mushy (a.k.a. "two-phase") zone, a thixotropic slurry is formed, which becomes the feed for the casting operation. In the rheocasting route (a.k.a. "slurry-on-demand" or "SoD"), one starts from the liquid state, and the thixotropic slurry is formed directly from the melt via careful thermal management of the system; the slurry is subsequently fed into the die cavity. Of these two routes, rheocasting is favored in that there is no premium added to the billet cost, and the scrap recycling issues are alleviated. The CRP (Trade Marked) is a process where the molten metal flows through a reactor prior to casting. The role of the reactor is to ensure that copious nucleation takes place and that the nuclei are well distributed throughout the system prior to entering the casting cavity. The CRP (Trade Marked) has been successfully applied in hyper-eutectic Al-Si alloys (i.e., 390 alloy) where two liquids of equal or different compositions and temperatures are mixed in the reactor and creating a SSM slurry. The process has been mostly

  7. 3D primary grain shapes resulting from semi-solid metal processing

    CSIR Research Space (South Africa)

    Curle, Ulyate A

    2017-07-01

    Full Text Available ) size. Are these 2D globules also spherical in shape in 3D or are these 2D shapes remnants of the 3D shapes after sectioning along planes? An Al-Si-Mg alloy is semi-solid processed using a patented processing coil that induces contactless stirring while...

  8. Semi-solid high pressure die casting of metal matrix composites produced by liquid state processing

    CSIR Research Space (South Africa)

    Ivanchev, L

    2012-10-01

    Full Text Available stirring. The composite was then transferred to a High Pressure Die Casting (HPDC) machine in the semi-solid state. The micron size particles were found to be predominantly in the intergranular eutectic while the nano-particles were predominantly...

  9. Rheo-processing of an alloy specifically designed for semi-solid metal processing based on the Al-Mg-Si system

    International Nuclear Information System (INIS)

    Patel, J.B.; Liu, Y.Q.; Shao, G.; Fan, Z.

    2008-01-01

    Semi-solid metal (SSM) processing is a promising technology for forming alloys and composites to near-net shaped products. Alloys currently used for SSM processing are mainly conventional aluminium cast alloys. This is an obstacle to the realisation of full potential of SSM processing, since these alloys were originally designed for liquid state processing and not for semi-solid state processing. Therefore, there is a significant need for designing new alloys specifically for semi-solid state processing to fulfil its potential. In this study, thermodynamic calculations have been carried out to design alloys based on the Al-Mg-Si system for SSM processing via the 'rheo-route'. The suitability of a selected alloy composition has been assessed in terms of the criteria considered by the thermodynamic design process, mechanical properties and heat treatability. The newly designed alloy showed good processability with rheo-processing in terms of good control of solid fraction during processing and a reasonably large processing window. The mechanical property variation was very small and the alloy showed good potential for age hardening by T5 temper heat treatment after rheo-processing

  10. Influence of temper condition on microstructure and mechanical properties of semisolid metal processed Al–Si–Mg alloy A356

    CSIR Research Space (South Africa)

    Moller, H

    2009-01-01

    Full Text Available The microstructures and mechanical properties of strontium modified semisolid metal high pressure die cast A356 alloy are presented. The alloy A356-F (as cast) has a globular primary grain structure containing a fine eutectic. Solution treatment...

  11. Microstructural Evolution during DPRM Process of Semisolid Ledeburitic D2 Tool Steel

    OpenAIRE

    M. N. Mohammed; M. Z. Omar; J. Syarif; Z. Sajuri; M. S. Salleh; K. S. Alhawari

    2013-01-01

    Semisolid metal processing is a relatively new technology that offers several advantages over liquid processing and solid processing because of the unique behaviour and characteristic microstructure of metals in this state. With the aim of finding a minimum process chain for the manufacture of high-quality production at minimal cost for forming, the microstructural evolution of the ledeburitic AISI D2 tool steel in the semisolid state was studied experimentally. The potential of the direct pa...

  12. Near net shape forming unsing semi-solid metal forming

    CSIR Research Space (South Africa)

    Govender, G

    2005-10-01

    Full Text Available (NRC) – UBE • Semi-Solid Rheocasting (SSR) – MIT • New Semi-Solid Casting – Hitachi • Sub-liquidus Casting (SLC) –JLH Technologies & THT Presses • Slurry on Demand (SoD) – AEMP 2005 Contech –USA Citation – USA Intermet – USA Stampal - ITALY... Stampal - producing engine brackets for Fiat PUNTO 50000 pcs per month New Rheocasting (NRC) - UBE 2005 Semi-Solid Rheocasting – MIT 2005 Hitachi Process 2005 SLC Process 2005 Advantages and Disadvantages of Rheocasting Advantages Disadvantages...

  13. Method and apparatus for semi-solid material processing

    Science.gov (United States)

    Han, Qingyou [Knoxville, TN; Jian, Xiaogang [Knoxville, TN; Xu, Hanbing [Knoxville, TN; Meek, Thomas T [Knoxville, TN

    2009-02-24

    A method of forming a material includes the steps of: vibrating a molten material at an ultrasonic frequency while cooling the material to a semi-solid state to form non-dendritic grains therein; forming the semi-solid material into a desired shape; and cooling the material to a solid state. The method makes semi-solid castings directly from molten materials (usually a metal), produces grain size usually in the range of smaller than 50 .mu.m, and can be easily retrofitted into existing conventional forming machine.

  14. Simulation of the infiltration process of a ceramic open-pore body with a metal alloy in semi-solid state to design the manufacturing of interpenetrating phase composites

    Science.gov (United States)

    Schomer, Laura; Liewald, Mathias; Riedmüller, Kim Rouven

    2018-05-01

    Metal-ceramic Interpenetrating Phase Composites (IPC) belong to a special subcategory of composite materials and reveal enhanced properties compared to conventional composite materials. Currently, IPC are produced by infiltration of a ceramic open-pore body with liquid metal applying high pressure and I or high temperature to avoid residual porosity. However, these IPC are not able to gain their complete potential, because of structural damages and interface reactions occurring during the manufacturing process. Compared to this, the manufacturing of IPC using the semi-solid forming technology offers great perspectives due to relative low processing temperatures and reduced mechanical pressure. In this context, this paper is focusing on numerical investigations conducted by using the FLOW-3D software for gaining a deeper understanding of the infiltration of open-pore bodies with semi-solid materials. For flow simulation analysis, a geometric model and different porous media drag models have been used. They have been adjusted and compared to get a precise description of the infiltration process. Based on these fundamental numerical investigations, this paper also shows numerical investigations that were used for basically designing a semi-solid forming tool. Thereby, the development of the flow front and the pressure during the infiltration represent the basis of the evaluation. The use of an open and closed tool cavity combined with various geometries of the upper die shows different results relating to these evaluation arguments. Furthermore, different overflows were designed and its effects on the pressure at the end of the infiltration process were investigated. Thus, this paper provides a general guideline for a tool design for manufacturing of metal-ceramic IPC using semi-solid forming.

  15. Rheo-processing of semi-solid metal alloys: a new technology for manufacturing automotive and aerospace components

    CSIR Research Space (South Africa)

    Ivanchev, L

    2008-01-01

    Full Text Available The latest trend in the automotive industry to produce fuel-efficient vehicles has resulted in the increased use of aluminium and magnesium alloys. Liquid metal high pressure die-casting (HPDC) currently satisfies the bulk of the automotive industry...

  16. Rheo-processing of semi-solid metal alloys: a new technology for manufacturing Automotive and aerospace components - Conference paper

    CSIR Research Space (South Africa)

    Ivanchev, L

    2006-02-01

    Full Text Available -solid forming processes. The CSIR in SA, developed and patented a rheocasting process and equipment for semi solid casting, which is in the commercialization stage and an automotive component will be manufactured soon....

  17. Technical cost modelling for a novel semi-solid metal (SSM) casting processes for automotive component manufacturing

    CSIR Research Space (South Africa)

    Tlale, NS

    2008-09-01

    Full Text Available to predict the cost structure of a newly developed manufacturing process if it is to be considered by manufacturing enterprises for development to substitute a process that is in use. The costs of the new SSM technologies was established by technical cost...

  18. Technical cost modelling for a novel semi-solid metal (SSM) casting processes for automotive component manufacturing

    CSIR Research Space (South Africa)

    Tlale, NS

    2008-09-01

    Full Text Available . It has been well established that over 70% of the total development cost of a product and its manufacturing process is decided during the design phase, although this phase accounts for less than 7% of the total costs. It is thus important to be able...

  19. Semi-solid metal forming of beryllium-reinforced aluminum alloys

    International Nuclear Information System (INIS)

    Haws, W.; Lane, L.; Marder, J.; Nicholas, N.

    1995-01-01

    A Powder Metallurgy (PM) based, Semi-Solid Metal (SSM) forming process has been developed to produce low cost near-net shapes of beryllium-reinforced aluminum alloys. Beryllium acts as a reinforcing additive to the aluminum, in which there is nearly no mutual solid solubility. The modulus of elasticity of the alloy dramatically increases, while the density and thermal expansion coefficient decrease with increasing beryllium content. The material is suitable for complex thermal management and vibration resistance applications, as well as for airborne components which are density and stiffness sensitive. The forming process involves heating a blank of the material to a temperature at which the aluminum is semi-solid and the beryllium is solid. The semi-solid blank is then injected without turbulence into a permanent mold. High quality, near net shape components can be produced which are functionally superior to those produced by other permanent mold processes. Dimensional accuracy is equivalent to or better than that obtained in high pressure die casting. Cost effectiveness is the primary advantage of this technique compared to other forming processes. The advantages and limitations of the process are described. Physical and mechanical property data are presented, as well as directions for future investigation

  20. Study on the rheoformability of semi-solid 7075 wrought aluminum alloy using seed process =

    Science.gov (United States)

    Zhao, Qinfu

    Semisolid metal forming is becoming more and more attractive in the foundry industry due to its low cost and easy operation to produce high quality near-net-shape components. Over the past years, semisolid forming technique is mainly applied on the casting aluminum alloys due to their superior castability because of low melting temperature and viscosity. In semisolid forming field, thixoforming has been majorly used which involves of reheating the billet into semisolid state followed by casting process. Rheocasting is a more economic semisolid processing compared to thixoforming, which the semisolid billet is produced directly from liquid phase. The SEED process is one of reliable rheocasting techniques to produce high quality semisolid billets. To produce high quality semisolid billets, their unique rheological properties have been the most important issue need to be fully investigated. The aim of present project is to produce high quality semisolid AA7075 billets by SEED process and analyze their rheological properties under various process conditions. The effect of the SEED processing parameters and grain refiners on the semisolid microstructure and rheoformability were investigated. The deformation and rheological behavior of the semisolid billets of AA7075 base and its grain-refined alloys were studied using parallel-plate viscometer. In the first part, the evolution of liquid fraction to temperature of semisolid AA7075 alloy was investigated using Differential Scanning Calorimetry (DSC). It was found that the liquidus and solidus temperature of AA7075 alloy were 631 °C and 490°C respectively. And the corresponding temperatures of solid fraction of 40% and 60% were 622°C and 610°C, which was recognized as the temperature window for semisolid forming of this alloy. In the second part, the semisolid slurries were rheocasted using SEED technology and the effect of the SEED process parameters like swirling frequency and demolding temperature on evolution of

  1. Microstructural evolution during DPRM process of semisolid ledeburitic D2 tool steel.

    Science.gov (United States)

    Mohammed, M N; Omar, M Z; Syarif, J; Sajuri, Z; Salleh, M S; Alhawari, K S

    2013-01-01

    Semisolid metal processing is a relatively new technology that offers several advantages over liquid processing and solid processing because of the unique behaviour and characteristic microstructure of metals in this state. With the aim of finding a minimum process chain for the manufacture of high-quality production at minimal cost for forming, the microstructural evolution of the ledeburitic AISI D2 tool steel in the semisolid state was studied experimentally. The potential of the direct partial remelting (DPRM) process for the production of AISI D2 with a uniform globular microstructure was revealed. The liquid fraction was determined using differential scanning calorimetry. The microstructures of the samples were investigated using an optical microscope and a scanning electron microscope equipped with an energy dispersive spectroscopy analyser, while X-ray phase analysis was performed to identify the phase evolution and the type of carbides. Mechanical characterisation was completed by hardness measurements. The typical microstructure after DPRM consists of metastable austenite which was located particularly in the globular grains (average grain size about 50 μ m), while the remaining interspaces were filled by precipitated eutectic carbides on the grain boundaries and lamellar network.

  2. Microstructural Evolution during DPRM Process of Semisolid Ledeburitic D2 Tool Steel

    Directory of Open Access Journals (Sweden)

    M. N. Mohammed

    2013-01-01

    Full Text Available Semisolid metal processing is a relatively new technology that offers several advantages over liquid processing and solid processing because of the unique behaviour and characteristic microstructure of metals in this state. With the aim of finding a minimum process chain for the manufacture of high-quality production at minimal cost for forming, the microstructural evolution of the ledeburitic AISI D2 tool steel in the semisolid state was studied experimentally. The potential of the direct partial remelting (DPRM process for the production of AISI D2 with a uniform globular microstructure was revealed. The liquid fraction was determined using differential scanning calorimetry. The microstructures of the samples were investigated using an optical microscope and a scanning electron microscope equipped with an energy dispersive spectroscopy analyser, while X-ray phase analysis was performed to identify the phase evolution and the type of carbides. Mechanical characterisation was completed by hardness measurements. The typical microstructure after DPRM consists of metastable austenite which was located particularly in the globular grains (average grain size about 50 μm, while the remaining interspaces were filled by precipitated eutectic carbides on the grain boundaries and lamellar network.

  3. Microstructural Evolution during DPRM Process of Semisolid Ledeburitic D2 Tool Steel

    Science.gov (United States)

    Mohammed, M. N.; Omar, M. Z.; Syarif, J.; Sajuri, Z.; Salleh, M. S.; Alhawari, K. S.

    2013-01-01

    Semisolid metal processing is a relatively new technology that offers several advantages over liquid processing and solid processing because of the unique behaviour and characteristic microstructure of metals in this state. With the aim of finding a minimum process chain for the manufacture of high-quality production at minimal cost for forming, the microstructural evolution of the ledeburitic AISI D2 tool steel in the semisolid state was studied experimentally. The potential of the direct partial remelting (DPRM) process for the production of AISI D2 with a uniform globular microstructure was revealed. The liquid fraction was determined using differential scanning calorimetry. The microstructures of the samples were investigated using an optical microscope and a scanning electron microscope equipped with an energy dispersive spectroscopy analyser, while X-ray phase analysis was performed to identify the phase evolution and the type of carbides. Mechanical characterisation was completed by hardness measurements. The typical microstructure after DPRM consists of metastable austenite which was located particularly in the globular grains (average grain size about 50 μm), while the remaining interspaces were filled by precipitated eutectic carbides on the grain boundaries and lamellar network. PMID:24223510

  4. Microstructure of Semi-Solid 6063 Alloy Fabricated by Radial Forging Combined with Unidirectional Compression Recrystallization and Partial Melting Process

    Directory of Open Access Journals (Sweden)

    Wang Yongfei

    2017-01-01

    Full Text Available Radial forging combined with unidirectional compression (RFCUM is introduced in recrystallization and partial melting (RAP to fabricate semi-solid 6063 aluminum alloy, which can be defined as a process of RFCUM-RAP. In this study, the microstructures of semi-solid 6063 alloy prepared by semi-solid isothermal treatment (SSIT and RFCUM-RAP processes are investigated. The results show that, the solid grains of semi-solid alloy prepared by SSIT are large and irregular. However, solid grains of semi-solid billet prepared by RFCUC-RAP are fine and spherical. Additionally, during RFCUC-RAP process, with the increase of isothermal holding time, the shape of solid grain is more and more spherical, but the size of solid grain is gradually increased. To obtain ideal semi-solid microstructure, the optimal isothermal holding temperature and time are 630 °C and 5~10 min, respectively.

  5. Issues in the validation of CFD modelling of semi-solid metal forming

    International Nuclear Information System (INIS)

    Ward, P.J.; Atkinson, H.V.; Kirkwood, D.H.; Liu, T.Y.; Chin, S.B.

    2000-01-01

    Modelling of die filling during semi-solid metal processing (thixoforming) places particular demands on the CFD package being used. Not only are the velocities of the metal slurry in the die very high, the viscosity is too. Furthermore, the viscosity changes with shear rate (i.e. with changes in cross sectional area of the region the slurry travels through) and with time, as the injected material is thixotropic. The CFD software therefore requires good free surface tracking, accurate implicit solutions of the flow equations (as the CPU times for explicit solutions at high viscosities are impractical) and a model that adequately describes the slurry thixotropy. Finally, reliable, experimentally determined viscosity data are required. This paper describes the experiments on tin-lead and aluminium alloy slurries using compressive tests and rotating cylinder viscometry, followed by modelling using FLOW-3D. This package is known for its ability to track free surfaces accurately. Compressive tests allow rapid changes in shear rate to be imparted to the slurry, without wall slip, while the simple geometry of the viscometer makes it possible to compare analytical and numerical solutions. It is shown that the implicit viscous solver in its original form can reproduce the general trends found in the compressive and viscometry tests. However, sharp changes in shear rate lead to overestimation of pressure gradients in the slurry, making it difficult to separate these effects from those due to thixotropic breakdown. In order to achieve this separation, it is necessary to implement a more accurate implicit solver, which is currently under development. (author)

  6. Phase Evolution and Mechanical Behavior of the Semi-Solid SIMA Processed 7075 Aluminum Alloy

    Directory of Open Access Journals (Sweden)

    Behzad Binesh

    2016-02-01

    Full Text Available Microstructural and mechanical behaviors of semi-solid 7075 aluminum alloy were investigated during semi-solid processing. The strain induced melt activation (SIMA process consisted of applying uniaxial compression strain at ambient temperature and subsequent semi-solid treatment at 600–620 °C for 5–35 min. Microstructures were characterized by scanning electron microscope (SEM, energy dispersive spectroscopy (EDS, and X-ray diffraction (XRD. During the isothermal heating, intermetallic precipitates were gradually dissolved through the phase transformations of α-Al + η (MgZn2 → liquid phase (L and then α-Al + Al2CuMg (S + Mg2Si → liquid phase (L. However, Fe-rich precipitates appeared mainly as square particles at the grain boundaries at low heating temperatures. Cu and Si were enriched at the grain boundaries during the isothermal treatment while a significant depletion of Mg was also observed at the grain boundaries. The mechanical behavior of different SIMA processed samples in the semi-solid state were investigated by means of hot compression tests. The results indicated that the SIMA processed sample with near equiaxed microstructure exhibits the highest flow resistance during thixoforming which significantly decreases in the case of samples with globular microstructures. This was justified based on the governing deformation mechanisms for different thixoformed microstructures.

  7. Simulation and experimental verification of the filling process of semi-solid die forging for cup shell

    Directory of Open Access Journals (Sweden)

    Jianbo TAN

    2015-06-01

    Full Text Available The filling mold process of semi-solid alloy blank influences severely the forming and properties of finished piece. In this paper, DEFORM is applied to simulate the process of cup-type 6061 alloy die forging casting. The influences of the temperature of semi-solid alloy blank, preheating temperature, and downward press speed of pressure head on process of mold filling and velocity field are investigated. The results show that the mold filling of semi-solid alloy paste smoothly fills along the whole of mould cavity in “total wall thickness” form when the temperature of semi-solid alloy blank is 620 ℃, preheating temperature of pressure head is 200 ℃ and speed of pressure head is 40 mm/s. Along with the increase of the preheating temperature of pressure head, the filling process of the semi-solid alloy paste trends toward stable when the temperature of semi-solid alloy blank is 620 ℃ and the speed of pressure head is 20 mm/s. Along with the increasing of the temperature of semi-solid alloy, the process of mould filling becomes off balance and the liquid becomes turbulent flow. The velocity field in the process of mould filling affects severely the structure uniformity of the finished product.

  8. Simulation and experimental verification of the filling process of semi-solid die forging for cup shell

    OpenAIRE

    Jianbo TAN; Zichao WANG; Dongxu WANG

    2015-01-01

    The filling mold process of semi-solid alloy blank influences severely the forming and properties of finished piece. In this paper, DEFORM is applied to simulate the process of cup-type 6061 alloy die forging casting. The influences of the temperature of semi-solid alloy blank, preheating temperature, and downward press speed of pressure head on process of mold filling and velocity field are investigated. The results show that the mold filling of semi-solid alloy paste smoothly fills along th...

  9. Characterization of semi-solid processing of aluminium alloy 7075 with Sc and Zr additions

    Energy Technology Data Exchange (ETDEWEB)

    Rogal, Ł., E-mail: l.rogal@imim.pl [Institute of Metallurgy and Materials Science of the Polish Academy of Sciences, 25 Reymonta St., 30-059 Krakow (Poland); Dutkiewicz, J. [Institute of Metallurgy and Materials Science of the Polish Academy of Sciences, 25 Reymonta St., 30-059 Krakow (Poland); Atkinson, H.V. [The University of Leicester, Department of Engineering University Road, Leicester, LE1 7RH (United Kingdom); Lityńska-Dobrzyńska, L.; Czeppe, T. [Institute of Metallurgy and Materials Science of the Polish Academy of Sciences, 25 Reymonta St., 30-059 Krakow (Poland); Modigell, M. [RWTH Aachen—Department of Mechanical Process Engineering, 55 Templergraben St., Aachen (Germany)

    2013-09-15

    For thixoforming (semi-solid processing) it is necessary to have a fine globular microstructure in a semi-solid range. Here this has been obtained for 7075 aluminium alloy by addition of modifying agents: 0.5 weight % of scandium and zirconium. The thixoforming process was carried out at 632 °C which gave about 23 volume % of liquid phase. The microstructure of the thixo-formed part (a rotor) consisted of globular grains surrounded by precipitates of secondary phase. The average hardness of thixo-formed parts was 105 HV{sub 5} and the tensile strength 300 MPa. T6 heat treatments were performed with solutionisation at 450 °C for 30 min and 10 h. In both cases the ageing time was set as 18 h at 120 °C. The heat treatments led to an increase in average tensile strength up to 495 MPa. Transmission Electron Microscopy (TEM) analysis enabled the identification of precipitates of the metastable dispersoids of L1{sub 2}–Al{sub 3} (Zr, Sc) and η′ (MgZn{sub 2}) phases in the alloy after the thixoforming and T6 treatment. The measurements of rheological properties of 7075Al alloy with Sc and Zr additions in the semi-solid range indicated an increase of particle size and spheroidization leading to an observable decrease of viscosity during isothermal shearing. A shear rate jump experiment showed that with increasing shear rate the viscosity rapidly falls.

  10. Effect of initial as-cast microstructure on semisolid microstructure of AZ91D alloy during the strain-induced melt activation process

    International Nuclear Information System (INIS)

    Wang, J.G.; Lin, H.Q.; Li, Y.Q.; Jiang, Q.C.

    2008-01-01

    The effects of different as-cast microstructures which were initially cast in graphite, metal, sand and firebrick moulds, respectively on the semisolid microstructure of AZ91D alloy, have been investigated during the strain-induced melt activation (SIMA) process. The experimental results showed that the moulds with high cooling capacity could produce the fine-grained as-cast microstructure in which the fine α-Mg dendrites were surrounded by a narrow layer of eutectic mixtures. After compressive deformation, in the fine-grained as-cast microstructure, the more systemic strain energy would be gradually accumulated and abundantly stored due to uniform inner crystal lattice distortion, so the recrystallization was easily induced by the stored strain energy at the elevated temperature. As a channel for the diffusion of atoms, the subgrain boundary along which Al element was enriched, foremost melted above the eutectic temperature and resulted in the separation of neighboring subgrains from primary dendrites. Therefore, the refining role of recrystallization on the microstructural evolution from dendrite to globular particles in morphology was easier to play in the fine-grained as-cast microstructure, which was advantageous for the production of fine-grained semisolid microstructure. Additionally, in the fine-grained as-cast microstructure, the melting fracture of narrow secondary dendritic arms was easy to occur in their roots, which also attributed to the production of fine globular grains in semisolid microstructure from primary dendrites. The finer dendrites in the initial as-cast alloy could evolve into the finer globular grains with relatively small grain size distribution range in the semisolid microstructure during partial remelting; therefore, the finer the dendrites in the initial as-cast microstructure, the better were the tensile properties of the evolved semisolid microstructure

  11. Semi-solid A356 alloy slurry for rheocasting prepared by a new process

    Directory of Open Access Journals (Sweden)

    Liu Zheng

    2013-05-01

    Full Text Available To obtain the semi-solid slurry with uniform and fine structure morphology that satisfies the requirement of rheocasting process, a new process for preparing semi-solid Al alloy slurry was developed, in which local chilling was combined with low superheat pouring and slight electromagnetic stirring (LSPSEMS. The morphology and the size of primary α-Al in the A356 alloy slurry prepared with the new process, i.e., LSPSEMS with local chilling, were investigated using MIAPS image analyzing software, and the grain refinement mechanism was discussed. The results indicate that the semi-solid primary phase consists of particle-like or globular-like α-Al, and the morphology and grain size of primary α-Al in the slurry can be markedly improved by the new process. The fine primary α-Al distributes uniformly in the slurry, which satisfies the requirement of rheocasting. Compared with the alloy prepared by LSPSEMS, the average equal-area-circle grain diameter of primary α-Al in semi-solid A356 alloy ingot prepared by the new process is decreased from 85.6 μm to 68.8 μm at the central area, 112.6 μm to 77.6 μm at the transition area and is 84.7 μm in the edge area, respectively. The corresponding shape factor of primary α-Al is increased from 0.78 to 0.83, 0.54 to 0.77 and 0.28 to 0.59, respectively. In addition, the pouring temperature could be suitably raised from 620-630 ℃ of the traditional process to 650 ℃ using this technique, which is convenient for practical operation. The mechanism of grain refinement, in the new process, is that the local chilling quickens up the temperature decrease in the center of the melt. The nuclei could not grow up in a short time so the finer grains are formed in the melt.

  12. Modelling and optimization of semi-solid processing of 7075 Al alloy

    Science.gov (United States)

    Binesh, B.; Aghaie-Khafri, M.

    2017-09-01

    The new modified strain-induced melt activation (SIMA) process presented by Binesh and Aghaie-Khafri was optimized using a response surface methodology to improve the thixotropic characteristics of semi-solid 7075 alloy. The responses, namely the average grain size and the shape factor, were considered as functions of three independent input variables: effective strain, isothermal holding temperature and time. Mathematical models for the responses were developed using the regression analysis technique, and the adequacy of the models was validated by the analysis of variance method. The calculated results correlated fairly well with the experiments. It was found that all the first- and second-order terms of the independent parameters and the interactive terms of the effective strain and holding time were statistically significant for the responses. In order to simultaneously optimize the responses, the desirable values for the effective strain, holding temperature and time were predicted to be 5.1, 609 °C and 14 min, respectively, when employing the desirability function approach. Based on the optimization results, a significant improvement in the average grain size and shape factor of the semi-solid slurry prepared by the new modified SIMA process was observed.

  13. Effects of silicon, copper and iron on static and dynamic properties of alloy 206 (aluminum-copper) in semi-solids produced by the SEED process

    Science.gov (United States)

    Lemieux, Alain

    The advantages of producing metal parts by rheocasting are generally recognised for common foundry alloys of Al-Si. However, other more performing alloys in terms of mechanical properties could have a great interest in specialized applications in the automotive industry, while remaining competitive in the forming. Indeed, the growing demand for more competitive products requires the development of new alloys better suited to semi-solid processes. Among others, Al-Cu alloys of the 2XX series are known for their superior mechanical strength. However, in the past, 2XX alloys were never candidates for pressure die casting. The main reason is their propensity to hot tearing. Semi-solid processes provide better conditions for molding with the rheological behavior of dough and molding temperatures lower reducing this type of defect. In the initial phase, this research has studied factors that reduce hot tearing susceptibility of castings produced by semi-solid SEED of alloy 206. Subsequently, a comparative study on the tensile properties and fatigue was performed on four variants of the alloy 206. The results of tensile strength and fatigue were compared with the specifications for applications in the automotive industry and also to other competing processes and alloys. During this study, several metallurgical aspects were analyzed. The following main points have been validated: i) the main effects of compositional variations of silicon, iron and copper alloy Al-Cu (206) on the mechanical properties, and ii) certain relationships between the mechanism of hot cracking and the solidification rate in semi-solid. Parts produced from the semi-solid paste coming from the SEED process combined with modified 206 alloys have been successfully molded and achieved superior mechanical properties than the requirements of the automotive industry. The fatigue properties of the two best modified 206 alloys were higher than those of A357 alloy castings and are close to those of the

  14. Microstructural evolution and rheological properties of AA6063 alloy produced by semisolid processing (SIMA and MHD)

    International Nuclear Information System (INIS)

    Bustos, O.; Leiva, R.; Sanchez, C.; Ordonez, S.; Carvajal, L.; Mannheim, R.

    2007-01-01

    In this work the rheological behaviour and the microstructural evolution of alloy AA6063 submitted to two different processing routes were studied: cold deformation and partial fusion (SIMA process) and magneto hydrodynamic stirring during its solidification (MHD process). The microstructural evolution during the isothermal holding was studied to verify if the Ost wald ripening mechanisms, classic growth and coalescence, are applicable to alloys made by these processing routes. The rheological properties were evaluated using a compression rheometer with parallel plates and digital capture of position and time data. Compression tests were made in short cylinders extracted from ingots that showed: a dendritic microstructure typical of as cast material, a typical microstructure of cold deformed material and a microstructure of materials obtained by MHD process. It was found that a globular microstructure has a typical behaviour of a fluid when being formed in semisolid state, contrary to the behaviour of the as cast dendritic microstructure. In addition, the mechanisms that operate in the microstructural evolution during the isothermal holdings were verified, through metallographic analysis. (Author) 29 refs

  15. Formation of semisolid, oligomerized aqueous SOA: lab simulations of cloud processing.

    Science.gov (United States)

    Hawkins, Lelia N; Baril, Molly J; Sedehi, Nahzaneen; Galloway, Melissa M; De Haan, David O; Schill, Gregory P; Tolbert, Margaret A

    2014-02-18

    Glyoxal, methylglyoxal, glycolaldehyde, and hydroxyacetone form N-containing and oligomeric compounds during simulated cloud processing with small amines. Using a novel hygroscopicity tandem differential mobility analysis (HTDMA) system that allows varied humidification times, the hygroscopic growth (HG) of each of the resulting products of simulated cloud processing was measured. Continuous water uptake (gradual deliquescence) was observed beginning at ∼ 40% RH for all aldehyde-methylamine products. Particles containing ionic reaction products of either glyoxal or glycine were most hygroscopic, with HG between 1.16 and 1.20 at 80% RH. Longer humidification times (up to 20 min) produced an increase in growth factors for glyoxal-methylamine (19% by vol) and methylglyoxal-methylamine (8% by vol) aerosol, indicating that unusually long equilibration times can be required for HTDMA measurements of such particles. Glyoxal- and methylglyoxal-methylamine aerosol particles shattered in Raman microscopy impact-flow experiments, revealing that the particles were semisolid. Similar experiments on glycolaldehyde- and hydroxyacetone-methylamine aerosol found that the aerosol particles were liquid when dried for glyoxal > glycolaldehyde = hydroxyacetone, likely caused by the speed of oligomer formation in each system.

  16. Rheologic behaviors of A356 aluminum alloy billet produced by semisolid continuous casting process

    Directory of Open Access Journals (Sweden)

    Shuming XING

    2004-08-01

    Full Text Available The experiments for rheologic behaviors of semisolid continous casting billets of A356 alloy in semisolid state has been carried out with a multifunctional rheometer. The results show that the deformation rate increases with loading time, the maximum strain reaches 120% (which is one time larger than that of traditional casting billet and the strain can be rapidly eliminated to 10% after unloading. Moreover, there is a critic stress for billet deformation even in semisolid state, which is named as critic shear stress. This stress increases with the decreasing of heating time. The rheologic behaviors can be expressed by five elements mechanical model and can be modified with the increasing of heating time.

  17. Semi-solid process of 2024 wrought aluminum alloy by strain induced melt activation

    Directory of Open Access Journals (Sweden)

    Surachai Numsarapatnuk

    2013-10-01

    Full Text Available The aim of this study is to develop a production process of a fine globular structure feedstock of the 2024 aluminumalloy suitable for subsequent semi-solid forming. The 2024 wrought aluminum alloy was first annealed to reduce the effect ofwork hardening. Then, strain was induced in the alloy by cold compression. After that the microstructural evolution duringpartial melting was investigated. The samples were subjected to full annealing at 415°C for 3 hrs prior to cold compression of40% reduction of area (RA with 3 mm/min strain rate. After that samples were partially melted at 620°C with varying holdingtime from 0 to 60 min followed by water quenching. The grain size and the average grain diameter of solid grains weremeasured using the linear intercept method. The globularization was interpreted in terms of shape factor. Liquid fraction andthe distribution of the eutectic liquid was also investigated. It was found that during partial melting, the globular morphologywas formed by the liquid wetting and fragmentation of high angle boundaries of recrystallized grains. The suitable semi-solidmicrostructure was obtained from a condition of full annealing, 40% cold working and partial melting at 620°C for 6 minholding time. The near globular grains obtained in the range of 0-60 min consisted of uniform spheroid grains with an averagegrain diameter ranged from 73 to 121 m, quenched liquid fraction was approximately 13–27% and the shape factor was greaterthan 0.6. At a holding time of less than 6 min, grain coarsening was dominant by the immigration of high-angle grainboundaries. At a longer holding time, liquid fraction increased and Ostwald ripening was dominant. The coarsening rateconstant for the 2024 Al alloy was 400.36 mm3.s-1. At a soaking time of 60 min, it was found that a minimum diameter differencewas 1.06% with coarsening index n=3 in a power law equation. The non-dendritic slug of 2024 alloy was rapid compressedinto a disc with 90%RA

  18. Interface analysis of A1 matrix composites produced by hot isostatic pressing, squeeze casting and semi-solid processing

    International Nuclear Information System (INIS)

    Shamsul, J.B.; Zainal Arifin Ahmad; Faaizulaswad, M.S.; Azmi, R.

    2000-01-01

    The interface analysis has been carried out an aluminium based composites system produced by hot isostatic pressing, squeeze casting and semi-solid processing. A range of different fabrication techniques has been used to produce different types of microstructure of Al 2124 (Al-Cu-Mg) reinforced with 5 weight % SiC particles. Blending followed by hot isostatic pressing is used to fabricate composite I. Composite II was 6061 (Al-Si-Mg) wrought aluminium alloy reinforced with fibres of alumina-silica (V f = 0.58) and fabricated by squeeze casting. Finally, A356 (AlSi7Mg0.3) alloy was reinforced with 20 Vol.% of SiC particles (13 μm) and namely as composite III. Composite III is fabricated by semi-solid processing. Interface analysis was done by optical microscopy, scanning and transmission electron microscopy. Composite I exhibited good interface bonding and dislocation was also observed near the interface. Elements such as Al, Fe, Cr, Mn were found near the interface of composite II and intermetallic of iron rich inclusion and Mg 2 Si were observed near the interface of composite III. (Author)

  19. Semi-solid twin-roll casting process of magnesium alloy sheets

    International Nuclear Information System (INIS)

    Watari, H.; Davey, K.; Rasgado, M.T. Alonso; Haga, T.; Koga, N.

    2004-01-01

    An experimental approach has been performed to ascertain the effectiveness of semi-solid strip casting using a horizontal twin roll caster. The demand for light-weight products with high strength has grown recently due to the rapid development of automobile and aircraft technology. One key to such development has been utilization of magnesium alloys, which can potentially reduce the total product weight. However, the problems of utilizing magnesium alloys are still mainly related to high manufacturing cost. One of the solutions to this problem is to develop magnesium casting-rolling technology in order to produce magnesium sheet products at competitive cost for commercial applications. In this experiment, magnesium alloy AZ31B was used to ascertain the effectiveness of semi-solid roll strip casting for producing magnesium alloy sheets. The temperature of the molten magnesium, and the roll speeds of the upper and lower rolls, (which could be changed independently), were varied to find an appropriate manufacturing condition. Rolling and heat treatment conditions were changed to examine which condition would be appropriate for producing wrought magnesium alloys with good formability. Microscopic observation of the crystals of the manufactured wrought magnesium alloys was performed. It has been found that a limiting drawing ratio of 2.7 was possible in a warm deep drawing test of the cast magnesium alloy sheets after being hot rolled

  20. Three-dimensional granular model of semi-solid metallic alloys undergoing solidification: Fluid flow and localization of feeding

    International Nuclear Information System (INIS)

    Sistaninia, M.; Phillion, A.B.; Drezet, J.-M.; Rappaz, M.

    2012-01-01

    A three-dimensional (3-D) granular model which simulates fluid flow within solidifying alloys with a globular microstructure, such as that found in grain refined Al alloys, is presented. The model geometry within a representative volume element (RVE) consists of a set of prismatic triangular elements representing the intergranular liquid channels. The pressure field within the liquid channels is calculated using a finite elements (FEs) method assuming a Poiseuille flow within each channel and flow conservation at triple lines. The fluid flow is induced by solidification shrinkage and openings at grain boundaries due to deformation of the coherent solid. The granular model predictions are validated against bulk data calculated with averaging techniques. The results show that a fluid flow simulation of globular semi-solid materials is able to reproduce both a map of the 3-D intergranular pressure and the localization of feeding within the mushy zone. A new hot cracking sensitivity coefficient is then proposed. Based on a mass balance performed over a solidifying isothermal volume element, this coefficient accounts for tensile deformation of the semi-solid domain and for the induced intergranular liquid feeding. The fluid flow model is then used to calculate the pressure drop in the mushy zone during the direct chill casting of aluminum alloy billets. The predicted pressure demonstrates that deep in the mushy zone where the permeability is low the local pressure can be significantly lower than the pressure predicted by averaging techniques.

  1. Contribution to the rheological testing of pharmaceutical semisolids.

    Science.gov (United States)

    Siska, B; Snejdrova, E; Machac, I; Dolecek, P; Martiska, J

    2018-01-22

    Rheological behaviour of pharmaceutical semisolid preparations significantly affects manufacturing process, administration, stability, homogeneity of incorporated drug, accuracy of dosing, adhesion in the place of application, drug release, and resulting therapeutic effect of the product. We performed test of consistency by penetrometry, rotational, oscillation and creep tests, and squeeze and tack tests of model samples to introduce methods suitable for characterization and comparison of semisolids in practice. Penetrometry is a simple method allowing sorting the semisolids to low and high stress-resistant materials but deficient for rheological characterization of semisolids. Value of yield stress, generally considered to be appropriate feature of semisolids, is significantly influenced by the method of testing and the way of evaluation. The hysteresis loops of model semisolids revealed incomplete thixotropy, therefore, three-step thixotropy test was employed. Semisolids showed nonlinear response in the creep phase of tests and partial recovery of structure by storing energy in the recovery phase. Squeeze and tack tests seem to be convenient ways for comparison of semisolids. Our study can contribute to a better understanding of different flow behaviour of semisolids given by different physicochemical properties of excipients and can bring useful approaches to evaluation and comparison of semisolids in practice.

  2. Microstructure of Semi-Solid Billets Produced by Electromagnetic Stirring and Behavior of Primary Particles during the Indirect Forming Process

    Directory of Open Access Journals (Sweden)

    Chul Kyu Jin

    2018-04-01

    Full Text Available An A356 alloy semi-solid billet was fabricated using electromagnetic stirring. After inserting the semi-solid billet into an indirect die, a thin plate of 1.2 mm thickness was fabricated by applying compression. The microstructure of the semi-solid billets fabricated in various stirring conditions (solid fraction and stirring force were analyzed. The deformation and behavior of the primary α-Al particles were analyzed for various parameters (solid fraction, die friction, compression rate, and compression pressure. In the stirred billets, a globular structure was dominant, while a dendrite structure was dominant in the unstirred billets. As the solid fraction decreased and the stirring current increased, the equivalent diameter and roundness of the primary α-Al particles decreased. The primary α-Al particle sizes were reduced as the compressing velocity increased, while a greater number of particles could move as the compressing pressure increased. As the path over which the motion occurred became smoother, the fluidity of the particles improved. Under compression, bonded primary α-Al particles became separated into individual particles again, as the bonds were broken. As wearing caused by friction and collisions between the particles during this motion occurred, the particle sizes were reduced, and the particle shapes become increasingly spheroid.

  3. 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.

  4. Ferrous Metal Processing Plants

    Data.gov (United States)

    Department of Homeland Security — This map layer includes ferrous metal processing plants in the United States. The data represent commodities covered by the Minerals Information Team (MIT) of the...

  5. Nonferrous Metal Processing Plants

    Data.gov (United States)

    Department of Homeland Security — This map layer includes nonferrous metal processing plants in the United States. The data represent commodities covered by the Minerals Information Team (MIT) of the...

  6. T6 heat treatment of semi-solid metal processed alloy A356

    CSIR Research Space (South Africa)

    Moller, H

    2008-01-01

    Full Text Available -exponential factor, Q the apparent activation energy in J/mol and R the universal gas constant = 8.314 J/mol K). The equations that describe the time to reach maximum hardness (tT6) are given by equation 1 (with prior natural aging time) and equation 2 (for... quench to artificial aging does not have an influence on the apparent activation energy (Q). It does, however, decrease the pre-exponential factor C, thereby resulting in a much faster artificial aging response. The apparent activation energies...

  7. Comparison of heat treatment response of semisolid metal processed alloys A356 and F357

    CSIR Research Space (South Africa)

    Moller, H

    2010-01-01

    Full Text Available p phase. This phase, which dissolves in alloy A356 during solution treatment, persists in F357 and decreases the amount of magnesium in solid solution. This is the likely origin of the decrease in the aging response of the F357 alloy. The tensile...

  8. Natural and artificial aging response of semisolid metal processed Al–Si–Mg alloy A356

    CSIR Research Space (South Africa)

    Moller, H

    2007-12-01

    Full Text Available aging at 180uC (Table 2). It can be seen from Table 2 that it takes approximately six times longer to reach peak hardness at 160uC compared to at 180uC. The diffusivity of silicon in aluminium is about double that of magnesium in aluminium... in the content of alloying elements. In Al–Mg–Si alloys containing an excess of silicon, the decomposition of the super- saturated solid solution (SSS) is believed to occur as follows7 SSS?(MgzSi)clusters=GP(I)spherical ?b=GP(II)needles?b0rodsz...

  9. Natural and artificial aging response of semi-solid metal processed alloy A356

    CSIR Research Space (South Africa)

    Möller, H

    2008-09-01

    Full Text Available oC between 1 and 5 hours without any prior natural aging. A natural aging period as short as 1 hour results in a hardness peak (rather than a plateau) to be reached during artificial aging after 4 hours at 180oC...

  10. Actinide metal processing

    International Nuclear Information System (INIS)

    Sauer, N.N.; Watkin, J.G.

    1992-01-01

    A process for converting an actinide metal such as thorium, uranium, or plutonium to an actinide oxide material by admixing the actinide metal in an aqueous medium with a hypochlorite as an oxidizing agent for sufficient time to form the actinide oxide material and recovering the actinide oxide material is described together with a low temperature process for preparing an actinide oxide nitrate such as uranyl nitrate. Additionally, a composition of matter comprising the reaction product of uranium metal and sodium hypochlorite is provided, the reaction product being an essentially insoluble uranium oxide material suitable for disposal or long term storage

  11. A double metal process

    International Nuclear Information System (INIS)

    Hawley, F.; Vasche, G.; Caywood, J.M.; Houck, B.; Boyce, J.; Tso, L.

    1988-01-01

    A dual layer metallization process is studied using a Tungsten 10% Titanium/Molybdenum sandwich (TiW/Mo) first metal with an Al/.5% Cu for the second metal. This metallization process has: 1) very reliable shallow junction contacts without junction spiking, 2) very high electromigration resistance and (3) A very smooth defect free surface throughout the process. Contact resistance of 50 and 30 ohm-um2 for P and N type silicon respectively is achieved. The TiW/Mo film stress is studied and an optimum condition for low compressive stress is defined. The TiW/Mo is etched using a corrosion free etch process. Electromigration data is presented showing TiW/Mo to be at least an order of magnitude better than Al/Si. The intermetal oxide layer is a planarized sandwich of LTO/SOG/LTO providing a smooth positive slope surface for the Metal 2. Metal l/Metal 2 via resistances are studied with 1.25 ohm-um2 values obtained

  12. A Microstructural Evaluation of Friction Stir Welded 7075 Aluminum Rolled Plate Heat Treated to the Semi-Solid State

    Directory of Open Access Journals (Sweden)

    Ava Azadi Chegeni

    2018-01-01

    Full Text Available Two rolled plates of 7075 aluminum alloy were used as starting material. The plates were welded using a simultaneous double-sided friction stir welding (FSW process. One way of obtaining feedstock materials for Semi-solid processing or thixoforming is via deformation routes followed by partial melting in the semi-solid state. As both the base plate materials and the friction weld area have undergone extensive deformation specimens were subjected to a post welding heat-treatment in the semi-solid range at a temperature of 628 °C, for 3 min in order to observe the induced microstructural changes. A comparison between the microstructural evolution and mechanical properties of friction stir welded plates was performed before and after the heat-treatment in the Base Metal (BM, the Heat Affected Zone (HAZ, the Thermomechanically Affected Zone (TMAZ and the Nugget Zone (NZ using optical microscopy, Scanning Electron microscopy (SEM and Vickers hardness tests. The results revealed that an extremely fine-grained structure, obtained in the NZ after FSW, resulted in a rise of hardness from the BM to the NZ. Furthermore, post welding heat-treatment in the semi-solid state gave rise to a consistent morphology throughout the material which was similar to microstructures obtained by the thixoforming process. Moreover, a drop of hardness was observed after heat treatment in all regions as compared to that in the welded microstructure.

  13. The Effect of Temperature and Rotational Speed on Structure and Mechanical Properties of Cast Cu Base Alloy (Cu-Al-Si-Fe) Welded by Semisolid Stir Joining Method

    Science.gov (United States)

    Ferasat, Keyvan; Aashuri, Hossein; Kokabi, Amir Hossein; Shafizadeh, Mahdi; Nikzad, Siamak

    2015-12-01

    Semisolid stir joining has been under deliberation as a possible method for joining of copper alloys. In this study, the effect of temperature and rotational speed of stirrer on macrostructure evaluation and mechanical properties of samples were investigated. Optical microscopy and X-ray diffraction were performed for macro and microstructural analysis. A uniform micro-hardness profile was attained by semisolid stir joining method. The ultimate shear strength and bending strength of welded samples were improved in comparison with the cast sample. There is also lower area porosity in welded samples than the cast metal. The mechanical properties were improved by increasing temperature and rotational speed of the joining process.

  14. Tailorable Burning Behavior of Ti14 Alloy by Controlling Semi-Solid Forging Temperature.

    Science.gov (United States)

    Chen, Yongnan; Yang, Wenqing; Zhan, Haifei; Zhang, Fengying; Huo, Yazhou; Zhao, Yongqing; Song, Xuding; Gu, Yuantong

    2016-08-16

    Semi-solid processing (SSP) is a popular near-net-shape forming technology for metals, while its application is still limited in titanium alloy mainly due to its low formability. Recent works showed that SSP could effectively enhance the formability and mechanical properties of titanium alloys. The processing parameters such as temperature and forging rate/ratio, are directly correlated with the microstructure, which endow the alloy with different chemical and physical properties. Specifically, as a key structural material for the advanced aero-engine, the burn resistant performance is a crucial requirement for the burn resistant titanium alloy. Thus, this work aims to assess the burning behavior of Ti14, a kind of burn resistant alloy, as forged at different semi-solid forging temperatures. The burning characteristics of the alloy are analyzed by a series of burning tests with different burning durations, velocities, and microstructures of burned sample. The results showed that the burning process is highly dependent on the forging temperature, due to the fact that higher temperatures would result in more Ti₂Cu precipitate within grain and along grain boundaries. Such a microstructure hinders the transport of oxygen in the stable burning stage through the formation of a kind of oxygen isolation Cu-enriched layer under the burn product zone. This work suggests that the burning resistance of the alloy can be effectively tuned by controlling the temperature during the semi-solid forging process.

  15. Direct observation of grain rotations during coarsening of a semisolid Al-Cu alloy

    DEFF Research Database (Denmark)

    Dake, Jules M.; Oddershede, Jette; Sørensen, Henning O.

    2016-01-01

    ideal arrangements of constituent powders while ignoring their underlying crystallinity, achieve at best a qualitative description of the rearrangement, densification, and coarsening of powder compacts during thermal processing. Treating a semisolid Al-Cu alloy as a model system for late-stage sintering......Sintering is a key technology for processing ceramic and metallic powders into solid objects of complex geometry, particularly in the burgeoning field of energy storage materials. The modeling of sintering processes, however, has not kept pace with applications. Conventional models, which assume...

  16. Investigation of the T4 and T6 heat treatment cycles of semi-solid processed aluminium alloy A356

    CSIR Research Space (South Africa)

    Moller, H

    2008-01-01

    Full Text Available of the solution treatment time at 540 C from 6 hours to 1 hour does not alter the T4 or T6 tensile properties of the SSM processed A356 alloy. Slightly better impact properties are obtained with the shorter solution treatment. This could lead to time and energy...

  17. Microbiological metal extraction processes

    International Nuclear Information System (INIS)

    Torma, A.E.

    1991-01-01

    Application of biotechnological principles in the mineral processing, especially in hydrometallurgy, has created new opportunities and challenges for these industries. During the 1950's and 60's, the mining wastes and unused complex mineral resources have been successfully treated in bacterial assisted heap and dump leaching processes for copper and uranium. The interest in bio-leaching processes is the consequence of economic advantages associated with these techniques. For example, copper can be produced from mining wastes for about 1/3 to 1/2 of the costs of copper production by the conventional smelting process from high-grade sulfide concentrates. The economic viability of bio leaching technology lead to its world wide acceptance by the extractive industries. During 1970's this technology grew into a more structured discipline called 'bio hydrometallurgy'. Currently, bio leaching techniques are ready to be used, in addition to copper and uranium, for the extraction of cobalt, nickel, zinc, precious metals and for the desulfurization of high-sulfur content pyritic coals. As a developing technology, the microbiological leaching of the less common and rare metals has yet to reach commercial maturity. However, the research in this area is very active. In addition, in a foreseeable future the biotechnological methods may be applied also for the treatment of high-grade ores and mineral concentrates using adapted native and/or genetically engineered microorganisms. (author)

  18. Liquid Segregation Phenomenological Behaviors of Ti14 Alloy during Semisolid Deformation

    Directory of Open Access Journals (Sweden)

    Y. N. Chen

    2014-05-01

    Full Text Available The liquid segregation phenomenon and its effect on deformation mechanism of Ti14 alloy in semisolid metal processing were investigated by thermal simulation test. Microstructure of depth profile was determined by cross-section quantitative metallography, and liquid segregation phenomenon was described by Darcy's law. The results show that segregation phenomenon was affected by solid fraction, strain rate, and deformation rate. More liquid segregated from center to edge portion with high strain rate and/or deformation ratio as well as low solid fraction, which caused different distribution of dominating deformation mechanism. The relationship between liquid segregation and main deformation mechanism was also discussed by phenomenological model.

  19. Extraterrestrial Metals Processing, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — The Extraterrestrial Metals Processing (EMP) system produces iron, silicon, and light metals from Mars, Moon, or asteroid resources in support of advanced human...

  20. On the hot cracking susceptibility of a semisolid aluminium 6061 weld: Application of a coupled solidification- thermomechanical model

    International Nuclear Information System (INIS)

    Rajani, H R Zareie; Phillion, A B

    2015-01-01

    A coupled solidification-thermomechanical model is presented that investigates the hot tearing susceptibility of an aluminium 6061 semisolid weld. Two key phenomena are considered: excessive deformation of the semisolid weld, initiating a hot tear, and the ability of the semisolid weld to heal the hot tear by circulation of the molten metal. The model consists of two major modules: weld solidification and thermomechanical analysis. 1) By means of a multi-scale model of solidification, the microstructural evolution of the semisolid weld is simulated in 3D. The semisolid structure, which varies as a function of welding parameters, is composed of solidifying grains and a network of micro liquid channels. The weld solidification module is utilized to obtain the solidification shrinkage. The size of the micro liquid channels is used as an indicator to assess the healing ability of the semisolid weld. 2) Using the finite element method, the mechanical interaction between the weld pool and the base metal is simulated to capture the transient force field deforming the semisolid weld. Thermomechanical stresses and shrinkage stresses are both considered in the analysis; the solidification contractions are extracted from the weld solidification module and applied to the deformation simulation as boundary conditions. Such an analysis enables characterization of the potential for excessive deformation of the weld. The outputs of the model are used to study the effect of welding parameters including welding current and speed, and also welding constraint on the hot cracking susceptibility of an aluminium alloy 6061 semisolid weld. (paper)

  1. Extraterrestrial Metals Processing, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The Extraterrestrial Metals Processing (EMP) system produces ferrosilicon, silicon monoxide, a glassy mixed oxide slag, and smaller amounts of alkali earth...

  2. X-ray tomography studies on porosity and particle size distribution in cast in-situ Al-Cu-TiB{sub 2} semi-solid forged composites

    Energy Technology Data Exchange (ETDEWEB)

    Mathew, James; Mandal, Animesh [School of Minerals, Metallurgical and Materials Engineering, Indian Institute of Technology, Bhubaneswar (India); Warnett, Jason; Williams, Mark A. [WMG, University of Warwick, Coventry CV4 7AL (United Kingdom); Chakraborty, Madhusudan [Department of Metallurgical and Materials Engineering, Indian Institute of Technology, Kharagpur (India); Srirangam, Prakash, E-mail: p.srirangam@warwick.ac.uk [WMG, University of Warwick, Coventry CV4 7AL (United Kingdom)

    2016-08-15

    X-ray computed tomography (XCT) was used to characterise the internal microstructure and clustering behaviour of TiB{sub 2} particles in in-situ processed Al-Cu metal matrix composites prepared by casting method. Forging was used in semi-solid state to reduce the porosity and to uniformly disperse TiB{sub 2} particles in the composite. Quantification of porosity and clustering of TiB{sub 2} particles was evaluated for different forging reductions (30% and 50% reductions) and compared with an as-cast sample using XCT. Results show that the porosity content was decreased by about 40% due to semi-solid forging as compared to the as-cast condition. Further, XCT results show that the 30% forging reduction resulted in greater uniformity in distribution of TiB{sub 2} particles within the composite compared to as-cast and the 50% forge reduction in semi-solid state. These results show that the application of forging in semi-solid state enhances particle distribution and reduces porosity formation in cast in-situ Al-Cu-TiB{sub 2} metal matrix composites. - Highlights: •XCT was used to visualise 3D internal structure of Al-Cu-TiB{sub 2} MMCs. •Al-Cu-TiB{sub 2} MMC was prepared by casting using flux assisted synthesis method. •TiB{sub 2} particles and porosity size distribution were evaluated. •Results show that forging in semi-solid condition decreases the porosity content and improve the particle dispersion in MMCs.

  3. Microstructures and Tensile Properties of Al–Cu Matrix Composites Reinforced with Nano-Sized SiCp Fabricated by Semisolid Stirring Process

    Directory of Open Access Journals (Sweden)

    Feng Qiu

    2017-02-01

    Full Text Available The nano-sized SiCp/Al–Cu composites were successfully fabricated by combining semisolid stirring with ball milling technology. Microstructures were examined by an olympus optical microscope (OM, field emission scanning electron microscope (FESEM and transmission electron microscope (TEM. Tensile properties were studied at room temperature. The results show that the α-Al dendrites of the composites were strongly refined, especially in the composite with 3 wt. % nano-sized SiCp, of which the morphology of the α-Al changes from 200 μm dendritic crystal to 90 μm much finer equiaxial grain. The strength and ductility of the composites are improved synchronously with the addition of nano-sized SiCp particles. The as-cast 3 wt. % nano-sized SiCp/Al–Cu composite displays the best tensile properties, i.e., the yield strength, ultimate tensile strength (UTS and fracture strain increase from 175 MPa, 310 MPa and 4.1% of the as-cast Al–Cu alloy to 220 MPa, 410 MPa and 6.3%, respectively. The significant improvement in the tensile properties of the composites is mainly due to the refinement of the α-Al dendrites, nano-sized SiCp strengthening, and good interface combination between the SiCp and Al–Cu alloys.

  4. METAL PLATING PROCESS

    Science.gov (United States)

    Walker, D.E.; Noland, R.A.

    1958-08-12

    A process ts described for obtaining a closely bonded coating of steel or iron on uranium. The process consists of providing, between the steel and uramium. a layer of silver. amd then pressure rolling tbe assembly at about 600 deg C until a reduction of from l0 to 50% has been obtained.

  5. Extraction process for removing metallic impurities from alkalide metals

    Science.gov (United States)

    Royer, Lamar T.

    1988-01-01

    A development is described for removing metallic impurities from alkali metals by employing an extraction process wherein the metallic impurities are extracted from a molten alkali metal into molten lithium metal due to the immiscibility of the alkali metals in lithium and the miscibility of the metallic contaminants or impurities in the lithium. The purified alkali metal may be readily separated from the contaminant-containing lithium metal by simple decanting due to the differences in densities and melting temperatures of the alkali metals as compared to lithium.

  6. Tritium processing using metal hydrides

    International Nuclear Information System (INIS)

    Mallett, M.W.

    1986-01-01

    E.I. duPont de Nemours and Company is commissioned by the US Department of Energy to operate the Savannah River Plant and Laboratory. The primary purpose of the plant is to produce radioactive materials for national defense. In keeping with current technology, new processes for the production of tritium are being developed. Three main objectives of this new technology are to ease the processing of, ease the storage of, and to reduce the operating costs of the tritium production facility. Research has indicated that the use of metal hydrides offers a viable solution towards satisfying these objectives. The Hydrogen and Fuels Technology Division has the responsibility to conduct research in support of the tritium production process. Metal hydride technology and its use in the storage and transportation of hydrogen will be reviewed

  7. PROCESS FOR PREPARING URANIUM METAL

    Science.gov (United States)

    Prescott, C.H. Jr.; Reynolds, F.L.

    1959-01-13

    A process is presented for producing oxygen-free uranium metal comprising contacting iodine vapor with crude uranium in a reaction zone maintained at 400 to 800 C to produce a vaporous mixture of UI/sub 4/ and iodine. Also disposed within the maction zone is a tungsten filament which is heated to about 1600 C. The UI/sub 4/, upon contacting the hot filament, is decomposed to molten uranium substantially free of oxygen.

  8. 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.

  9. Perceived creaminess of semi-solid foods

    NARCIS (Netherlands)

    Wijk, R.A.de; Terpstra, M.E.J.; Janssen, A.M.; Prinz, J.F.

    2006-01-01

    Results of sensory, physiological and physico-chemical studies from our laboratory on perceived creaminess of semi-solids foods are reviewed. Most results stem from studies using model vanilla custard desserts, allowing systematic variation of fat, flavor and thickener properties. The

  10. Numerical simulation of the induction heating of hybrid semi-finished materials into the semi-solid state

    Science.gov (United States)

    Seyboldt, Christoph; Liewald, Mathias

    2017-10-01

    Current research activities at the Institute for Metal Forming Technology (IFU) of the University of Stuttgart are focusing on the manufacturing of hybrid components using semi-solid forming strategies. As part of the research project "Hybrid interaction during and after thixoforging of multi-material systems", which is founded by the German Research Foundation (DFG), a thixoforging process for producing hybrid components with cohesive metal-to-metal connections is developed. In this context, this paper deals with the numerical simulation of the inductive heating process of hybrid semi-finished materials, consisting of two different aluminium alloys. By reason of the skin effect that leads to inhomogeneous temperature distributions during inductive heating processes, the aluminium alloy with the higher melting point is thereby assembled in the outer side and the alloy with the lower melting point is assembled in the core of the semi-finished material. In this way, the graded heat distribution can be adapted to the used materialś flow properties that are heavily heat dependent. Without this graded heat distribution a proper forming process in the semi-solid state will not be possible. For numerically modelling the inductive heating system of the institute, a coupling of the magnetostatic and the thermal solver was realized by using Ansys Workbench. While the electromagnetic field and its associated heat production rate were solved in a frequency domain, the temperature development was solved in the time based domain. The numerical analysis showed that because of the high thermal conductivity of the aluminium, which leads to a rapid temperature equalization in the semi-finished material, the heating process has to be fast and with a high frequency for produce most heat in the outer region of the material. Finally, the obtained numerical results were validated with experimental heating tests.

  11. Chemical ageing and transformation of diffusivity in semi-solid multi-component organic aerosol particles

    Science.gov (United States)

    Pfrang, C.; Shiraiwa, M.; Pöschl, U.

    2011-07-01

    Recent experimental evidence underlines the importance of reduced diffusivity in amorphous semi-solid or glassy atmospheric aerosols. This paper investigates the impact of diffusivity on the ageing of multi-component reactive organic particles approximating atmospheric cooking aerosols. We apply and extend the recently developed KM-SUB model in a study of a 12-component mixture containing oleic and palmitoleic acids. We demonstrate that changes in the diffusivity may explain the evolution of chemical loss rates in ageing semi-solid particles, and we resolve surface and bulk processes under transient reaction conditions considering diffusivities altered by oligomerisation. This new model treatment allows prediction of the ageing of mixed organic multi-component aerosols over atmospherically relevant timescales and conditions. We illustrate the impact of changing diffusivity on the chemical half-life of reactive components in semi-solid particles, and we demonstrate how solidification and crust formation at the particle surface can affect the chemical transformation of organic aerosols.

  12. Dynamic texture perception and oral processing of semi-solid food gels: Part 1: Comparison between QDA, progressive profiling and TDS

    NARCIS (Netherlands)

    Devezeaux de Lavergne, M.S.M.; Delft, van J.M.; Velde, van de F.; Boekel, van M.A.J.S.; Stieger, M.A.

    2015-01-01

    Texture perception of food is a dynamic phenomenon depending on food properties and oral processing. Several sensory techniques enable to measure texture perception over time. The aim of this study was to compare quantitative descriptive analysis (QDA), temporal dominance of sensation (TDS) and

  13. Process for improving metal production in steelmaking processes

    Science.gov (United States)

    Pal, Uday B.; Gazula, Gopala K. M.; Hasham, Ali

    1996-01-01

    A process and apparatus for improving metal production in ironmaking and steelmaking processes is disclosed. The use of an inert metallic conductor in the slag containing crucible and the addition of a transition metal oxide to the slag are the disclosed process improvements.

  14. Semi-solid near-net shape rheocasting of heat treatable wrought aluminum alloys

    CSIR Research Space (South Africa)

    Curle, UA

    2010-09-01

    Full Text Available Flexibility of the CSIR-RCS, induction stirring with simultaneous air cooling process, in combination with high pressure die casting is successfully demonstrated by semi-solid rheocasting of plates performed on commercial 2024, 6082 and 7075 wrought...

  15. Process for making rare earth metal chlorides

    International Nuclear Information System (INIS)

    Kruesi, P.R.

    1981-01-01

    An uncombined metal or a metal compound such as a sulfide, oxide, carbonate or sulfate is converted in a liquid salt bath to the corresponding metal chloride by reacting it with chlorine gas or a chlorine donor. The process applies to metals of groups 1b, 2a, 2b, 3a, 3b, 4a, 5a and 8 of the periodic table and to the rare earth metals. The chlorine donor may be ferric or sulfur chloride. The liquid fused salt bath is made up of chlorides of alkali metals, alkaline earth metals, ammonia, zinc and ferric iron. Because the formed metal chlorides are soluble in the liquid fused salt bath, they can be recovered by various conventional means

  16. 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.

  17. Modeling steel deformation in the semi-solid state

    CERN Document Server

    Hojny, Marcin

    2017-01-01

    This book addresses selected aspects of steel-deformation modelling, both at very high temperatures and under the conditions in which the liquid and the solid phases coexist. Steel-deformation modelling with its simultaneous solidification is particularly difficult due to its specificity and complexity. With regard to industrial applications and the development of new, integrated continuous casting and rolling processes, the issues related to modelling are becoming increasingly important. Since the numerous industrial tests that are necessary when traditional methods are used to design the process of continuous casting immediately followed by rolling are expensive, new modelling concepts have been sought. Comprehensive tests were applied to solve problems related to the deformation of steel with a semi-solid core. Physical tests using specialist laboratory instruments (Gleeble 3800thermo-mechanical simulator, NANOTOM 180 N computer tomography, Zwick Z250 testing equipment, 3D blue-light scanning systems), and...

  18. Advances in Thermal Spray Deposition of Billets for Particle Reinforced Light Metals

    International Nuclear Information System (INIS)

    Wenzelburger, Martin; Zimmermann, Christian; Gadow, Rainer

    2007-01-01

    Forming of light-metals in semi-solid state offers some advantages like low process temperatures, improved mould durability, good flow behavior and fine, globular microstructure of the final material. By the introduction of ceramic particles, increased elastic modulus and yield strength as well as wear resistance and creep behavior can be obtained. By semi-solid forging or semi-solid casting, particle reinforced metals (PRM) can be produced with improved matrix microstructure and beneficial forming process parameters compared to conventional MMC manufacturing techniques. The production of this kind of light metal matrix composites requires the supply of dense semi-finished parts with well defined volume fractions of homogeneously distributed particulate reinforcement. A manufacturing method for cylindrical light metal billets is described that applies thermal spraying as a build-up process for simultaneous deposition of matrix and reinforcement phase with cored wires as spraying material. Thermal spraying leads to small grain sizes and prevents dendrite formation. However, long process cycle times lead to billet heating and recrystallization of the matrix microstructure. In order to preserve small grain sizes that enable semi-solid forming, the thermal spraying process was analyzed by in-flight particle analysis and thermography. As a consequence, the deposition process was optimized by adaptation of the thermal spraying parameters and by application of additional cooling, leading to lower billet temperatures and finer PRM billet microstructure

  19. Process for cleaning radioactively contaminated metal surfaces

    International Nuclear Information System (INIS)

    Mihram, R.G.; Snyder, G.A.

    1975-01-01

    A process is described for removing radioactive scale from a ferrous metal surface, including the steps of initially preconditioning the surface by contacting it with an oxidizing solution (such as an aqueous solution of an alkali metal permanganate or hydrogen peroxide), then, after removal or decomposition of the oxidizing solution, the metallic surface is contacted with a cleaning solution which is a mixture of a mineral acid and a complexing agent (such as sulfuric acid and oxalic acid), and which preferably contains a corrosion inhibitor. A final step in the process is the treatment of the spent cleaning solution containing radioactive waste materials in solution by adding a reagent selected from the group consisting of calcium hydroxide or potassium permanganate and an alkali metal hydroxide to thereby form easily recovered metallic compounds containing substantially all of the dissolved metals and radioactivity. (auth)

  20. Semisolid forming of S48C steel grade

    Science.gov (United States)

    Plata, Gorka; Lozares, Jokin; Azpilgain, Zigor; Hurtado, Iñaki; Loizaga, Iñigo; Idoyaga, Zuriñe

    2017-10-01

    Steel production and component manufacturing industries have to face the challenge of globalization, trying to overcome the economic pressure to remain competitive. Moreover, the lightweighting trend of the latter years implies an even higher challenge to maintain the steel use. Therefore, advanced manufacturing processes will be the cornerstone. In this field, Semisolid forming (SSF) has demonstrated the capability of obtaining complex geometries and saving raw material and energy. Despite it is complicated the SSF of sound components, in Mondragon Unibertsitatea it has been successfully demonstrated the capability of producing strong enough automotive components with 42CrMo4 steel grade. In this work, we demonstrate the capability of SSF S48C steel grade with great mechanical properties.

  1. Process for electrolytically preparing uranium metal

    Science.gov (United States)

    Haas, Paul A.

    1989-01-01

    A process for making uranium metal from uranium oxide by first fluorinating uranium oxide to form uranium tetrafluoride and next electrolytically reducing the uranium tetrafluoride with a carbon anode to form uranium metal and CF.sub.4. The CF.sub.4 is reused in the fluorination reaction rather than being disposed of as a hazardous waste.

  2. Catalytic extraction processing of contaminated scrap metal

    International Nuclear Information System (INIS)

    Griffin, T.P.; Johnston, J.E.; Payea, B.M.; Zeitoon, B.M.

    1995-01-01

    Molten Metal Technology was awarded a contract to demonstrate the applicability of the Catalytic Extraction Process, a proprietary process that could be applied to US DOE's inventory of low level mixed waste. This paper is a description of that technology, and included within this document are discussions of: (1) Program objectives, (2) Overall technology review, (3) Organic feed conversion to synthetic gas, (4) Metal, halogen, and transuranic recovery, (5) Demonstrations, (6) Design of the prototype facility, and (7) Results

  3. Catalytic extraction processing of contaminated scrap metal

    International Nuclear Information System (INIS)

    Griffin, T.P.; Johnston, J.E.

    1994-01-01

    The contract was conceived to establish the commercial capability of Catalytic Extraction Processing (CEP) to treat contaminated scrap metal in the DOE inventory. In so doing, Molten Metal Technology, Inc. (MMT), pursued the following objectives: demonstration of the recycling of ferrous and non-ferrous metals--to establish that radioactively contaminated scrap metal can be converted to high-grade, ferrous and non-ferrous alloys which can be reused by DOE or reintroduced into commerce; immobilize radionuclides--that CEP will concentrate the radionuclides in a dense vitreous phase, minimize secondary waste generation and stabilize and reduce waste volume; destroy hazardous organics--that CEP will convert hazardous organics to valuable industrial gases, which can be used as feed gases for chemical synthesis or as an energy source; recovery volatile heavy metals--that CEP's off-gas treatment system will capture volatile heavy metals, such as mercury and lead; and establish that CEP is economical for processing contaminated scrap metal in the DOE inventory--that CEP is a more cost-effective and, complete treatment and recycling technology than competing technologies for processing contaminated scrap. The process and its performance are described

  4. Optimization and control of metal forming processes

    NARCIS (Netherlands)

    Havinga, Gosse Tjipke

    2016-01-01

    Inevitable variations in process and material properties limit the accuracy of metal forming processes. Robust optimization methods or control systems can be used to improve the production accuracy. Robust optimization methods are used to design production processes with low sensitivity to the

  5. Metals and Alloys Material Stabilization Process Plan

    Energy Technology Data Exchange (ETDEWEB)

    RISENMAY, H.R.; BURK, R.A.

    2000-05-18

    This Plan outlines the process for brushing metal and alloys in accordance with the path forward discussed in the Integrated Project Management Plan for the Plutonium Finishing Plant Stabilization and Deactivation Project, HNF-3617, and requirements set forth in the Project Management Plan for Materials Stabilization, HNF-3605. This plan provides the basis for selection of the location to process, the processes involved, equipment to be used, and the characterization of the contents of the can. The scope of the process is from retrieval of metals and alloys from storage to transfer back to storage in a repackaged configuration.

  6. Metals and Alloys Material Stabilization Process Plan

    International Nuclear Information System (INIS)

    RISENMAY, H.R.; BURK, R.A.

    2000-01-01

    This Plan outlines the process for brushing metal and alloys in accordance with the path forward discussed in the Integrated Project Management Plan for the Plutonium Finishing Plant Stabilization and Deactivation Project, HNF-3617, and requirements set forth in the Project Management Plan for Materials Stabilization, HNF-3605. This plan provides the basis for selection of the location to process, the processes involved, equipment to be used, and the characterization of the contents of the can. The scope of the process is from retrieval of metals and alloys from storage to transfer back to storage in a repackaged configuration

  7. Predicting the constitutive behavior of semi-solids via a direct finite element simulation: application to AA5182

    Science.gov (United States)

    Phillion, A. B.; Cockcroft, S. L.; Lee, P. D.

    2009-07-01

    The methodology of direct finite element (FE) simulation was used to predict the semi-solid constitutive behavior of an industrially important aluminum-magnesium alloy, AA5182. Model microstructures were generated that detail key features of the as-cast semi-solid: equiaxed-globular grains of random size and shape, interconnected liquid films, and pores at the triple-junctions. Based on the results of over fifty different simulations, a model-based constitutive relationship which includes the effects of the key microstructure features—fraction solid, grain size and fraction porosity—was derived using regression analysis. This novel constitutive equation was then validated via comparison with both the FE simulations and experimental stress/strain data. Such an equation can now be used to incorporate the effects of microstructure on the bulk semi-solid flow stress within a macro- scale process model.

  8. Predicting the constitutive behavior of semi-solids via a direct finite element simulation: application to AA5182

    International Nuclear Information System (INIS)

    Phillion, A B; Cockcroft, S L; Lee, P D

    2009-01-01

    The methodology of direct finite element (FE) simulation was used to predict the semi-solid constitutive behavior of an industrially important aluminum-magnesium alloy, AA5182. Model microstructures were generated that detail key features of the as-cast semi-solid: equiaxed-globular grains of random size and shape, interconnected liquid films, and pores at the triple-junctions. Based on the results of over fifty different simulations, a model-based constitutive relationship which includes the effects of the key microstructure features—fraction solid, grain size and fraction porosity—was derived using regression analysis. This novel constitutive equation was then validated via comparison with both the FE simulations and experimental stress/strain data. Such an equation can now be used to incorporate the effects of microstructure on the bulk semi-solid flow stress within a macro- scale process model

  9. Identification of the steel viscosity and dynamic yield stress for the numerical modelling of casting simulations in the semi-solid state

    Directory of Open Access Journals (Sweden)

    Solek K.

    2017-03-01

    Full Text Available Conditions of some casting processes cause flow of both liquid and semi-liquid metal alloys inside the die cavity. Generally, the continuous casting, squeeze casting or thixoforming could be classified as such processes. Design or optimisation of casting technology using numerical simulations requires knowledge of the rheological properties. The main objective of the experimental work, presented in this publication, is an analysis of the viscosity of 1.2080 (X210Cr12 high carbon steel in liquid and semisolid state. The secondary purpose of the experimental work was a development of the viscosity models used in continuous casting and thixoforming simulations. The significant achievement of this particular study was identification of thixotropy phenomenon which occurs not only during thixoforming, but also during magnetohydrodynamic stirring in continuous casting processes.

  10. Particle and liquid motion in semi-solid aluminium alloys: A quantitative in situ microradioscopy study

    International Nuclear Information System (INIS)

    Zabler, S.; Ershov, A.; Rack, A.; Garcia-Moreno, F.; Baumbach, T.; Banhart, J.

    2013-01-01

    Semi-solid melts exhibit a very unpredictable rheology and filling dynamics, when injected into thin-walled components. Optimization of the process requires an insight into the casting process during injection. For this purpose we injected semi-solid an Al–Ge alloy into two different thin channel geometries while recording high resolution radiographs at fast frame rates (up to 1000 images per s). Comparison of a bottleneck channel, which has previously been used for slower experiments, with a right-angle turn geometry reveals a significant influence of the channel shape on the flow behaviour of the particle–liquid mixture. While the bottleneck is quickly sealed with densified solid, turbulences in the right-angle turn apparently permit solid particles and clusters to move conjointly with the liquid and thus achieve a more complete filling. Single particle trajectories and rapid break-up of solid skeletons in such a system have been observed for the first time in situ

  11. Rheological behavior of semi-solid 7075 aluminum alloy at steady state

    Directory of Open Access Journals (Sweden)

    Li Yageng

    2014-03-01

    Full Text Available The further application of semi-solid processing lies in the in-depth fundamental study like rheological behavior. In this research, the apparent viscosity of the semi-solid slurry of 7075 alloy was measured using a Couette type viscometer. The effects of solid fraction and shearing rate on the apparent viscosity of this alloy were investigated under different processing conditions. It can be seen that the apparent viscosity increases with an increase in the solid fraction from 10% to 50% (temperature 620 篊 to 630 篊 at steady state. When the solid fraction was fixed, the apparent viscosity can be decreased by altering the shearing rate from 61.235 s-1 to 489.88 s-1 at steady state. An empirical equation that shows the effects of solid fraction and shearing rate on the apparent viscosity is fitted. The microstructure of quenched samples was examined to understand the alloy抯 rheological behavior.

  12. Stationary semi-solid battery module and method of manufacture

    Science.gov (United States)

    Slocum, Alexander; Doherty, Tristan; Bazzarella, Ricardo; Cross, III, James C.; Limthongkul, Pimpa; Duduta, Mihai; Disko, Jeffry; Yang, Allen; Wilder, Throop; Carter, William Craig; Chiang, Yet-Ming

    2015-12-01

    A method of manufacturing an electrochemical cell includes transferring an anode semi-solid suspension to an anode compartment defined at least in part by an anode current collector and an separator spaced apart from the anode collector. The method also includes transferring a cathode semi-solid suspension to a cathode compartment defined at least in part by a cathode current collector and the separator spaced apart from the cathode collector. The transferring of the anode semi-solid suspension to the anode compartment and the cathode semi-solid to the cathode compartment is such that a difference between a minimum distance and a maximum distance between the anode current collector and the separator is maintained within a predetermined tolerance. The method includes sealing the anode compartment and the cathode compartment.

  13. Mass fractionation processes of transition metal isotopes

    Science.gov (United States)

    Zhu, X. K.; Guo, Y.; Williams, R. J. P.; O'Nions, R. K.; Matthews, A.; Belshaw, N. S.; Canters, G. W.; de Waal, E. C.; Weser, U.; Burgess, B. K.; Salvato, B.

    2002-06-01

    Recent advances in mass spectrometry make it possible to utilise isotope variations of transition metals to address some important issues in solar system and biological sciences. Realisation of the potential offered by these new isotope systems however requires an adequate understanding of the factors controlling their isotope fractionation. Here we show the results of a broadly based study on copper and iron isotope fractionation during various inorganic and biological processes. These results demonstrate that: (1) naturally occurring inorganic processes can fractionate Fe isotope to a detectable level even at temperature ˜1000°C, which challenges the previous view that Fe isotope variations in natural system are unique biosignatures; (2) multiple-step equilibrium processes at low temperatures may cause large mass fractionation of transition metal isotopes even when the fractionation per single step is small; (3) oxidation-reduction is an importation controlling factor of isotope fractionation of transition metal elements with multiple valences, which opens a wide range of applications of these new isotope systems, ranging from metal-silicate fractionation in the solar system to uptake pathways of these elements in biological systems; (4) organisms incorporate lighter isotopes of transition metals preferentially, and transition metal isotope fractionation occurs stepwise along their pathways within biological systems during their uptake.

  14. Processing facility for metal waste

    International Nuclear Information System (INIS)

    Awano, Toshihiko; Kataoka, Yoshitsune.

    1998-01-01

    Each steps of temporarily storing materials to be reduced in the volume to a storage vessel, transferring them to a weighing machine by a conveyor, weighing them by a weighing machine, drying them by a drying means, packing them in containing canisters, sealing and welding them, carrying out the containing canisters after sealing are conducted independently respectively or optionally simultaneously in parallel. Accordingly, isolation from peripheral circumstances is ensured, and improvement of working efficiency, ensuring of safety and simplification of structure of processing devices can be attained. (T.M.)

  15. Pyrometallurgical process of actinide metal

    International Nuclear Information System (INIS)

    Yoo, Jae Hyung; Kang, Young Ho; Woo, Mun Sik; Hwang, Sung Chan

    1999-06-01

    Major subject on pyrometallurgical partitioning technology is to separate transmutation elements (TRU) from rare earth elements(RE). Distribution coefficients of TRU and RE between molten chloride and liquid cadmium were measured for reductive extraction, and TRU were separated from RE in simplified molten chloride system by electrorefining. And separation efficiency between TRU and RE were estimated by using thermodynamics data. The results indicate that uranium, neptunium and plutonium are easy to separate from RE but some amount of RE accompany americium, and that processes have to be optimized to attain good separation efficiency of TRU. (author)

  16. Atomization process for metal powder

    International Nuclear Information System (INIS)

    Lagutkin, Stanislav; Achelis, Lydia; Sheikhaliev, Sheikhali; Uhlenwinkel, Volker; Srivastava, Vikas

    2004-01-01

    A new atomization process has been developed, which combines pressure and gas atomization. The melt leaves the pressure nozzle as a hollow thin film cone. After the pre-filming step, the melt is atomized by a gas stream delivered by a ring nozzle. The objectives of this investigation are to achieve a narrow size distribution and low specific gas consumption compared to conventional gas atomization techniques. Both lead to a higher efficiency and low costs. Tin and some alloys have been atomized successfully with this technique. The mass median diameters from different experiments are between 20 and 100 μm. Sieving analysis of the tin powder shows close particle size distributions

  17. Semi-solid electrodes having high rate capability

    Energy Technology Data Exchange (ETDEWEB)

    Chiang, Yet-Ming; Duduta, Mihai; Holman, Richard; Limthongkul, Pimpa; Tan, Taison

    2017-11-28

    Embodiments described herein relate generally to electrochemical cells having high rate capability, and more particularly to devices, systems and methods of producing high capacity and high rate capability batteries having relatively thick semi-solid electrodes. In some embodiments, an electrochemical cell includes an anode and a semi-solid cathode. The semi-solid cathode includes a suspension of an active material of about 35% to about 75% by volume of an active material and about 0.5% to about 8% by volume of a conductive material in a non-aqueous liquid electrolyte. An ion-permeable membrane is disposed between the anode and the semi-solid cathode. The semi-solid cathode has a thickness of about 250 .mu.m to about 2,000 .mu.m, and the electrochemical cell has an area specific capacity of at least about 7 mAh/cm.sup.2 at a C-rate of C/4. In some embodiments, the semi-solid cathode slurry has a mixing index of at least about 0.9.

  18. Rheology of StelliteTM 21 Alloy in Semi-Solid State

    Directory of Open Access Journals (Sweden)

    Sołek K.

    2016-12-01

    Full Text Available The main objective of this study was to conduct an analysis of the rheological properties of StelliteTM 21 alloy in the semi-solid state, as the results could be used for identifying the appropriate temperature range for thixoforming of this alloy, and a secondary objective of the experimental work was the development of mathematical model of the alloy’s apparent viscosity. Such viscosity models are necessary for numerical simulations of the thixoforming processes. The StelliteTM 21 alloy exhibits high hardness and thus shaping in the semi-solid state is promising route of production of parts from this alloy. Within the confines of experimental work the measurement methods of the rheological properties at high temperatures was developed. They are based on the use of specially designed viscometer equipped with high temperature furnace.

  19. Development of Axial Continuous Metal Expeller for melt conditioning of alloys

    International Nuclear Information System (INIS)

    Cassinath, Z.; Prasada Rao, A.K.

    2016-01-01

    ACME (Axial, centrifugal metal expeller) is a novel processing technology developed independently for conditioning liquid metal prior to solidification processing. The ACME process is based on an axial compressor and uses a rotor stator mechanism to impose a high shear rate and a high intensity of turbulence to the liquid metal, so that the conditioned liquid metal has uniform temperature and uniform chemical composition as it is expelled. The microstructural refinement is achieved through the process of dendrite fragmentation while taking advantage of the thixotropic property of semisolid metal slurry so that it can be conveyed for further downstream operations. This paper introduces the concept and its advantages over current technologies. (paper)

  20. Development of Axial Continuous Metal Expeller for melt conditioning of alloys

    Science.gov (United States)

    Cassinath, Z.; Prasada Rao, A. K.

    2016-02-01

    ACME (Axial, centrifugal metal expeller) is a novel processing technology developed independently for conditioning liquid metal prior to solidification processing. The ACME process is based on an axial compressor and uses a rotor stator mechanism to impose a high shear rate and a high intensity of turbulence to the liquid metal, so that the conditioned liquid metal has uniform temperature and uniform chemical composition as it is expelled. The microstructural refinement is achieved through the process of dendrite fragmentation while taking advantage of the thixotropic property of semisolid metal slurry so that it can be conveyed for further downstream operations. This paper introduces the concept and its advantages over current technologies.

  1. Process for etching zirconium metallic objects

    International Nuclear Information System (INIS)

    Panson, A.J.

    1988-01-01

    In a process for etching of zirconium metallic articles formed from zirconium or a zirconium alloy, wherein the zirconium metallic article is contacted with an aqueous hydrofluoric acid-nitric acid etching bath having an initial ratio of hydrofluoric acid to nitric acid and an initial concentration of hydrofluoric and nitric acids, the improvement, is described comprising: after etching of zirconium metallic articles in the bath for a period of time such that the etching rate has diminished from an initial rate to a lesser rate, adding hydrofluoric acid and nitric acid to the exhausted bath to adjust the concentration and ratio of hydrofluoric acid to nitric acid therein to a value substantially that of the initial concentration and ratio and thereby regenerate the etching solution without removal of dissolved zirconium therefrom; and etching further zirconium metallic articles in the regenerated etching bath

  2. Study on the Microstructure and Liquid Phase Formation in a Semisolid Gray Cast Iron

    Science.gov (United States)

    Benati, Davi Munhoz; Ito, Kazuhiro; Kohama, Kazuyuki; Yamamoto, Hajime; Zoqui, Eugenio José

    2017-10-01

    The development of high-quality semisolid raw materials requires an understanding of the phase transformations that occur as the material is heated up to the semisolid state, i.e., its melting behavior. The microstructure of the material plays a very important role during semisolid processing as it determines the flow behavior of the material when it is formed, making a thorough understanding of the microstructural evolution essential. In this study, the phase transformations and microstructural evolution in Fe2.5C1.5Si gray cast iron specially designed for thixoforming processes as it was heated to the semisolid state were observed using in situ high-temperature confocal laser scanning microscopy. At room temperature, the alloy has a matrix of pearlite and ferrite with fine interdendritic type D flake graphite. During heating, the main transformations observed were graphite precipitation inside the grains and at the austenite grain boundaries; graphite flakes and graphite precipitates growing and becoming coarser with the increasing temperature; and the beginning of melting at around 1413 K to 1423 K (1140 °C to 1150 °C). Melting begins with the eutectic phase ( i.e., the carbon-rich phase) and continues with the primary phase (primary austenite), which is consumed as the temperature increases. Melting of the eutectic phase composed by coarsened interdendritic graphite flakes produced a semi-continuous liquid network homogeneously surrounding and wetting the dendrites of the solid phase, causing grains to detach from each other and producing the intended solid globules immersed in liquid.

  3. Processing method of radioactive metal wastes

    International Nuclear Information System (INIS)

    Uetake, Naoto; Urata, Megumu; Sato, Masao.

    1985-01-01

    Purpose: To reduce the volume and increase the density of radioactive metal wastes easily while preventing scattering of radioactivity and process them into suitable form to storage and treatment. Method: Metal wastes mainly composed of zirconium are discharged from nuclear power plants or fuel re-processing plants, and these metals such as zirconium and titanium vigorously react with hydrogen and rapidly diffuse as hydrides. Since the hydrides are extremely brittle and can be pulverized easily, they can be volume-reduced. However, since metal hydrides have no ductility, dehydrogenation is applied for the molding fabrication in view of the subsequent storage and processing. The dehydrogenation is easy like the hydrogenation and fine metal pieces can be molded in a small compression device. For the dehydrogenation, a temperature is slightly increased as compared with that in the hydrogenation, pressure is reduced through the vacuum evacuation system and the removed hydrogen is purified for reuse. The upper limit for the temperature of the hydrogenation is 680 0 C in order to prevent the scttering of radioactivity. (Kamimura, M.)

  4. An automatic granular structure generation and finite element analysis of heterogeneous semi-solid materials

    International Nuclear Information System (INIS)

    Sharifi, Hamid; Larouche, Daniel

    2015-01-01

    The quality of cast metal products depends on the capacity of the semi-solid metal to sustain the stresses generated during the casting. Predicting the evolution of these stresses with accuracy in the solidification interval should be highly helpful to avoid the formation of defects like hot tearing. This task is however very difficult because of the heterogeneous nature of the material. In this paper, we propose to evaluate the mechanical behaviour of a metal during solidification using a mesh generation technique of the heterogeneous semi-solid material for a finite element analysis at the microscopic level. This task is done on a two-dimensional (2D) domain in which the granular structure of the solid phase is generated surrounded by an intergranular and interdendritc liquid phase. Some basic solid grains are first constructed and projected in the 2D domain with random orientations and scale factors. Depending on their orientation, the basic grains are combined to produce larger grains or separated by a liquid film. Different basic grain shapes can produce different granular structures of the mushy zone. As a result, using this automatic grain generation procedure, we can investigate the effect of grain shapes and sizes on the thermo-mechanical behaviour of the semi-solid material. The granular models are automatically converted to the finite element meshes. The solid grains and the liquid phase are meshed properly using quadrilateral elements. This method has been used to simulate the microstructure of a binary aluminium–copper alloy (Al–5.8 wt% Cu) when the fraction solid is 0.92. Using the finite element method and the Mie–Grüneisen equation of state for the liquid phase, the transient mechanical behaviour of the mushy zone under tensile loading has been investigated. The stress distribution and the bridges, which are formed during the tensile loading, have been detected. (paper)

  5. Laser Processing Technology using Metal Powders

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Jeong-Hwan; Moon, Young-Hoon [Pusan National University, Busan (Korea, Republic of)

    2012-03-15

    The purpose of this paper is to review the state of laser processing technology using metal powders. In recent years, a series of research and development efforts have been undertaken worldwide to develop laser processing technologies to fabricate metal-based parts. Layered manufacturing by the laser melting process is gaining ground for use in manufacturing rapid prototypes (RP), tools (RT) and functional end products. Selective laser sintering / melting (SLS/SLM) is one of the most rapidly growing rapid prototyping techniques. This is mainly due to the processes's suitability for almost any materials, including polymers, metals, ceramics and many types of composites. The interaction between the laser beam and the powder material used in the laser melting process is one of the dominant phenomena defining feasibility and quality. In the case of SLS, the powder is not fully melted during laser scanning, therefore the SLS-processed parts are not fully dense and have relatively low strength. To overcome this disadvantage, SLM and laser cladding (LC) processes have been used to enable full melting of the powder. Further studies on the laser processing technology will be continued due to the many potential applications that the technology offers.

  6. Process for production of a metal hydride

    Science.gov (United States)

    Allen, Nathan Tait; Butterick, III, Robert; Chin, Arthur Achhing; Millar, Dean Michael; Molzahn, David Craig

    2014-08-12

    A process for production of a metal hydride compound MH.sub.x, wherein x is one or two and M is an alkali metal, Be or Mg. The process comprises combining a compound of formula (R.sup.1O).sub.xM with aluminum, hydrogen and at least one metal selected from among titanium, zirconium, hafnium, niobium, vanadium, tantalum and iron to produce a compound of formula MH.sub.x. R.sup.1 is phenyl or phenyl substituted by at least one alkyl or alkoxy group. A mole ratio of aluminum to (R.sup.1O).sub.xM is from 0.1:1 to 1:1. The catalyst is present at a level of at least 200 ppm based on weight of aluminum.

  7. INVESTIGATION OF THE METAL MELTING PROCESS

    Directory of Open Access Journals (Sweden)

    V. I. Timoshpolskij

    2006-01-01

    Full Text Available The nonlinear mathematical model of calculation of temperature fields in the process of metal melting is formulated and solved using the method of equivalent source taking into account nonlinearity of thermophysical properties of material and variable terms of heat exchange.

  8. Process technology - rare and refractory metals

    International Nuclear Information System (INIS)

    Gupta, C.K.; Bose, D.K.

    1989-01-01

    India has fairly rich resreves of rare and refractory metals. Abundant sources of ilmenite, rutile, zircon and rare earths are found in the placer deposits of the southern and eastern coasts of the country. Columbite-tantalite occur in mica and the mining belts of Bihar and cassiterite deposits are found in Bastar (Madhya Pradesh). Vanadium as a minor associate occurs in bauxites and in the vast deposits of titaniferrous magnetites. Over the years, research and development and pilot plant works in many research organisations in India have built up a sound technological base in the country for process metallurgy of many refractory and rare earth metals starting from their indigenous sources. The present paper provides a comprehensive view of the developments that have taken place till now on the processing of various refractory and rare earth metals with particular reference to the extensive work carried out at the Department of Atomic Energy. The coverage includes mineral benification separation of individual elements, preparation of pure intermediates, techniques of reduction to metal and final purification. The paper also reviews some of the recent developments that have been taken place in these fields and the potential application of these metals in the foreseeable future. (author). 22 refs., 18 fi g., 7 tabs

  9. Chemical ageing and transformation of diffusivity in semi-solid multi-component organic aerosol particles

    Directory of Open Access Journals (Sweden)

    C. Pfrang

    2011-07-01

    Full Text Available Recent experimental evidence underlines the importance of reduced diffusivity in amorphous semi-solid or glassy atmospheric aerosols. This paper investigates the impact of diffusivity on the ageing of multi-component reactive organic particles approximating atmospheric cooking aerosols. We apply and extend the recently developed KM-SUB model in a study of a 12-component mixture containing oleic and palmitoleic acids. We demonstrate that changes in the diffusivity may explain the evolution of chemical loss rates in ageing semi-solid particles, and we resolve surface and bulk processes under transient reaction conditions considering diffusivities altered by oligomerisation. This new model treatment allows prediction of the ageing of mixed organic multi-component aerosols over atmospherically relevant timescales and conditions. We illustrate the impact of changing diffusivity on the chemical half-life of reactive components in semi-solid particles, and we demonstrate how solidification and crust formation at the particle surface can affect the chemical transformation of organic aerosols.

  10. Sensing the gas metal arc welding process

    Science.gov (United States)

    Carlson, N. M.; Johnson, J. A.; Smartt, H. B.; Watkins, A. D.; Larsen, E. D.; Taylor, P. L.; Waddoups, M. A.

    1994-01-01

    Control of gas metal arc welding (GMAW) requires real-time sensing of the process. Three sensing techniques for GMAW are being developed at the Idaho National Engineering Laboratory (INEL). These are (1) noncontacting ultrasonic sensing using a laser/EMAT (electromagnetic acoustic transducer) to detect defects in the solidified weld on a pass-by-pass basis, (2) integrated optical sensing using a CCD camera and a laser stripe to obtain cooling rate and weld bead geometry information, and (3) monitoring fluctuations in digitized welding voltage data to detect the mode of metal droplet transfer and assure that the desired mass input is achieved.

  11. Relaxation processes during amorphous metal alloys heating

    International Nuclear Information System (INIS)

    Malinochka, E.Ya.; Durachenko, A.M.; Borisov, V.T.

    1982-01-01

    Behaviour of Te+15 at.%Ge and Fe+13 at.%P+7 at.%C amorphous metal alloys during heating has been studied using the method of differential scanning calorimetry (DSC) as the most convenient one for determination of the value of heat effects, activation energies, temperature ranges of relaxation processes. Thermal effects corresponding to high-temperature relaxation processes taking place during amorphous metal alloys (AMA) heating are detected. The change of ratio of relaxation peaks values on DSC curves as a result of AMA heat treatment can be explained by the presence of a number of levels of inner energy in amorphous system, separated with potential barriers, the heights of which correspond to certain activation energies of relaxation processes

  12. Improved leaching process for metal ores

    International Nuclear Information System (INIS)

    Kar-Kwan Yung, K.; Barlow, C.B.; Glass, J.R.

    1980-01-01

    The general overall sequence of process steps in the technique of the invention in set forth. In sequence, the ore is crushed, and solubilizing reagents and moisture are added to the crushed ore in preselected controlled portions. The mixture of ore, reagent, and moisture is then cured followed in the preferred process by conditioning for filtration. The slurry that is produced from conditioning is then subjected to multiple stage washing on a belt filter. The filtrate is further processed for metal value recovery and the solids are transported to tailings disposal

  13. Hygroscopic influence on the semisolid-to-liquid transition of secondary organic materials.

    Science.gov (United States)

    Bateman, Adam P; Bertram, Allan K; Martin, Scot T

    2015-05-14

    The effect of relative humidity (RH) on the rebound of particles composed of isoprene, α-pinene, and toluene secondary organic materials (SOMs) was studied. A three-arm impaction apparatus was used to study rebound from 5 to 95% RH at 298 K. Calibration experiments using sucrose particles of variable but known viscosities showed that the transition from rebounding to adhering particles occurred for a change in viscosity from 100 to 1 Pa s, corresponding to a transition from semisolid to liquid material. The experimentally determined rebound fractions of the studied SOMs were compared with results from a model of the rebound processes of hard particles, taking into account the particle kinetic energy, van der Waals forces, and RH-dependent capillary forces. For low RH values, the hard-particle model explained the diameter-dependent rebound behavior for all studied SOMs. For elevated RH, however, the experimental observations deviated from the model predictions. On the basis of the calibration experiments using sucrose particles as well as a comparison between the observations and the predictions of the hard-particle model, the interpretation is made that a semisolid-to-liquid transition occurred at elevated RH. Material softening, increased adhesion, or a combination of the two implied the action of additional modes of energy relaxation that were not included in the hard-particle model. The RH threshold for the semisolid-to-liquid phase transition was 40% RH for isoprene SOM, 70% for toluene SOM, and 70% for α-pinene SOM. A correlation between the rebound fraction and the hygroscopic growth factor G was demonstrated, implying that absorbed water volume was a dominant governing factor of the semisolid-to-liquid transition for the studied classes of SOM. Simple heuristic rules based on G of 1.15 for the semisolid-to-liquid phase transition could be used for prognostication of the SOM phase in modeling applications at 298 K. With respect to atmospheric processes, the

  14. Description of Latvian Metal Production and Processing Enterprises' Air Emissions

    OpenAIRE

    Pubule, J; Zahare, D; Blumberga, D

    2010-01-01

    The metal production and processing sector in Latvia has acquired a stable position in the national economy. Smelting of ferrous and nonferrous metals, production of metalware, galvanisation, etc. are developed in Latvia. The metal production and processing sector has an impact on air quality due to polluting substances which are released in the air from metal treatment processes. Therefore it is necessary to determine the total volume of emissions produced by the metal production and process...

  15. Laser processing of metals and alloys

    International Nuclear Information System (INIS)

    Goswami, G.L.; Kumar, Dilip; Roy, P.R.

    1988-01-01

    Laser, due to its high degree of coherence can produce powder density in the range of 10 3 -10 11 W/mm 2 . This high power density of the laser beam enables it to be utilized for many industrial applications, e.g. welding, cutting, drilling, surface treatment, etc. Laser processing of materials has many advantages, e.g. good quality product at high processing speed, least heat affected zone, minimum distortion, etc. In addition, the same laser system can be utilized for different applications, a very cost effective factor for any industry. Therefore laser has been adopted for processing of different materials for a wide range of applications and is now replacing conventional materials processing techniques on commercial merits with several economic and metallurgical advantages. Applications of laser to process materials of different thicknesses varying from 0.1 mm to 100 mm have demonstrat ed its capability as an important manufacturing tool for engineering industries. While lasers have most widely been utilized in welding, cutting and drilling they have also found applications in surface treatment of metals and alloys, e.g. transfor mation hardening and annealing. More recently, there has been significant amount of research being undertaken in laser glazing, laser surface alloying and laser cladding for obtaining improved surface properties. This report reviews the stat us of laser processing of metals and alloys emphasising its metallurgical aspects a nd deals with the different laser processes like welding, cutting, drilling and surface treatment highlighting the types and choice of laser and its interaction with metals and alloys and the applications of these processes. (author). 93 refs., 32 figs., 7 tables

  16. Semi-solid electrodes having high rate capability

    Energy Technology Data Exchange (ETDEWEB)

    Chiang, Yet-Ming; Duduta, Mihai; Holman, Richard; Limthongkul, Pimpa; Tan, Taison

    2017-11-28

    Embodiments described herein relate generally to electrochemical cells having high rate capability, and more particularly to devices, systems and methods of producing high capacity and high rate capability batteries having relatively thick semi-solid electrodes. In some embodiments, an electrochemical cell includes an anode, a semi-solid cathode that includes a suspension of an active material and a conductive material in a liquid electrolyte, and an ion permeable membrane disposed between the anode and the cathode. The semi-solid cathode has a thickness in the range of about 250 .mu.m-2,500 .mu.m, and the electrochemical cell has an area specific capacity of at least 5 mAh/cm.sup.2 at a C-rate of C/2.

  17. Solar Convective Furnace for Metals Processing

    Science.gov (United States)

    Patidar, Deepesh; Tiwari, Sheetanshu; Sharma, Piyush; Pardeshi, Ravindra; Chandra, Laltu; Shekhar, Rajiv

    2015-11-01

    Metals processing operations, primarily soaking, heat treatment, and melting of metals are energy-intensive processes using fossil fuels, either directly or indirectly as electricity, to operate furnaces at high temperatures. Use of concentrated solar energy as a source of heat could be a viable "green" option for industrial heat treatment furnaces. This paper introduces the concept of a solar convective furnace which utilizes hot air generated by an open volumetric air receiver (OVAR)-based solar tower technology. The potential for heating air above 1000°C exists. Air temperatures of 700°C have already been achieved in a 1.5-MWe volumetric air receiver demonstration plant. Efforts to retrofit an industrial aluminium soaking furnace for integration with a solar tower system are briefly described. The design and performance of an OVAR has been discussed. A strategy for designing a 1/15th-scale model of an industrial aluminium soaking furnace has been presented. Preliminary flow and thermal simulation results suggest the presence of recirculating flow in existing furnaces that could possibly result in non-uniform heating of the slabs. The multifarious uses of concentrated solar energy, for example in smelting, metals processing, and even fuel production, should enable it to overcome its cost disadvantage with respect to solar photovoltaics.

  18. Mesoporous metal oxides and processes for preparation thereof

    Energy Technology Data Exchange (ETDEWEB)

    Suib, Steven L.; Poyraz, Altug Suleyman

    2018-03-06

    A process for preparing a mesoporous metal oxide, i.e., transition metal oxide. Lanthanide metal oxide, a post-transition metal oxide and metalloid oxide. The process comprises providing an acidic mixture comprising a metal precursor, an interface modifier, a hydrotropic ion precursor, and a surfactant; and heating the acidic mixture at a temperature and for a period of time sufficient to form the mesoporous metal oxide. A mesoporous metal oxide prepared by the above process. A method of controlling nano-sized wall crystallinity and mesoporosity in mesoporous metal oxides. The method comprises providing an acidic mixture comprising a metal precursor, an interface modifier, a hydrotropic ion precursor, and a surfactant; and heating the acidic mixture at a temperature and for a period of time sufficient to control nano-sized wall crystallinity and mesoporosity in the mesoporous metal oxides. Mesoporous metal oxides and a method of tuning structural properties of mesoporous metal oxides.

  19. Catalysed electrolytic metal oxide dissolution processes

    International Nuclear Information System (INIS)

    Machuron-Mandard, X.

    1994-01-01

    The hydrometallurgical processes designed for recovering valuable metals from mineral ores as well as industrial wastes usually require preliminary dissolution of inorganic compounds in aqueous media before extraction and purification steps. Unfortunately, most of the minerals concerned hardly or slowly dissolve in acidic or basic solutions. Metallic oxides, sulfides and silicates are among the materials most difficult to dissolve in aqueous solutions. They are also among the main minerals containing valuable metals. The redox properties of such materials sometimes permit to improve their dissolution by adding oxidizing or reducing species to the leaching solution, which leads to an increase in the dissolution rate. Moreover, limited amounts of redox promoters are required if the redox agent is regenerated continuously thanks to an electrochemical device. Nuclear applications of such concepts have been suggested since the dissolution of many actinide compounds (e.g., UO 2 , AmO 2 , PuC, PuN,...) is mainly based on redox reactions. In the 1980s, improvements of the plutonium dioxide dissolution process have been proposed on the basis of oxidation-reduction principles, which led a few years later to the design of industrial facilities (e.g., at Marcoule or at the french reprocessing plant of La Hague). General concepts and well-established results obtained in France at the Atomic Energy Commission (''Commissariat a l'Energie Atomique'') will be presented and will illustrate applications to industrial as well as analytical problems. (author)

  20. Reliable processing of graphene using metal etchmasks

    Directory of Open Access Journals (Sweden)

    Peltekis Nikos

    2011-01-01

    Full Text Available Abstract Graphene exhibits exciting properties which make it an appealing candidate for use in electronic devices. Reliable processes for device fabrication are crucial prerequisites for this. We developed a large area of CVD synthesis and transfer of graphene films. With patterning of these graphene layers using standard photoresist masks, we are able to produce arrays of gated graphene devices with four point contacts. The etching and lift off process poses problems because of delamination and contamination due to polymer residues when using standard resists. We introduce a metal etch mask which minimises these problems. The high quality of graphene is shown by Raman and XPS spectroscopy as well as electrical measurements. The process is of high value for applications, as it improves the processability of graphene using high-throughput lithography and etching techniques.

  1. Method of processing radioactive metal wastes

    International Nuclear Information System (INIS)

    Inoue, Yoichi; Kitagawa, Kazuo; Tsuzura, Katsuhiko.

    1980-01-01

    Purpose: To enable long and safety storage for radioactive metal wastes such as used fuel cans after the procession or used pipe, instruments and the likes polluted with various radioactive substances, by compacting them to solidify. Method: Metal wastes such as used fuel cans, which have been cut shorter and reprocessed, are pressed into generally hexagonal blocks. The block is charged in a capsule of a hexagonal cross section made of non-gas permeable materials such as soft steels, stainless steels and the likes. Then, the capsule is subjected to static hydraulic hot pressing as it is or after deaeration and sealing. While various combinations are possible for temperature, pressure and time as the conditions for the static hydraulic hot pressing, dense block with no residual gas pores can be obtained, for example, under the conditions of 900 0 C, 1000 Kg/cm 2 and one hour where the wastes are composed of zircaloy. (Kawakami, Y.)

  2. METAL CHIP HEATING PROCESS INVESTIGATION (Part I

    Directory of Open Access Journals (Sweden)

    O. M. Dyakonov

    2007-01-01

    Full Text Available The main calculation methods for heat- and mass transfer in porous heterogeneous medium have been considered. The paper gives an evaluation of the possibility to apply them for calculation of metal chip heating process. It has been shown that a description of transfer processes in a chip has its own specific character that is attributed to difference between thermal and physical properties of chip material and lubricant-coolant components on chip surfaces. It has been determined that the known expressions for effective heat transfer coefficients can be used as basic ones while approaching mutually penetrating continuums. A mathematical description of heat- and mass transfer in chip medium can be considered as a basis of mathematical modeling, numerical solution and parameter optimization of the mentioned processes.

  3. New process for weld metal reliability

    International Nuclear Information System (INIS)

    Hebel, A.G.

    1985-01-01

    The industry-wide nature of weld cracking alerts one to the possibility that there is a fundamental law being overlooked. And in overlooking this law, industry is unable to counteract it. That law mandates that restraint during welding causes internal stress; internal stress causes weld metal to crack. Component restraint during welding, according to the welding standard, is the major cause of weld metal failures. When the metal working industry accepts this fact and begins to counter the effects of restraint, the number of weld failures experienced fall dramatically. Bonal Technologies, inc., of Detroit, has developed the first consistently effective non-thermal process to relieve stress caused by restraint during welding. Bonal's patented Mets-Lax sub-resonant stress relief acts as a restraint neutralizer when used during welding. Meta-Lax weld conditioning produces a finer more uniform weld grain structure. A finer, more uniform grain structure is a clear metallurgical indication of improved mechanical weld properties. Other benefits like less internal stress, and less warpage are also achieved

  4. Simulation of the metallic powders compaction process

    International Nuclear Information System (INIS)

    Prado, J.M.; Riera, M.D.

    1998-01-01

    The simulation by means of finite elements of the forming processes of mechanical components is a very useful tool for their design and validation. In this work, the simulation of the compaction of a metal powder is presented. The finite element software ABAQUS is used together with the modified CAM-clay plasticity model in order to represent the elastoplastic behaviour of the material. Density distributions are obtained and therefore the motion of the compaction punches which improve this distribution can be found. Stress distribution in the different parts of the mould can also be determined. (Author) 9 refs

  5. Gongronema Latifolium delays gastric emptying of semi-solid meals ...

    African Journals Online (AJOL)

    The aim of the study was to investigate sonographically the effect of Gongronema latifolium on gastric emptying of semi-solid meals in diabetic dogs. Twenty-five alloxan-induced diabetic dogs were randomly allotted into five groups of five dogs each in a randomised placebo-controlled study. These are placebo, prokinetic ...

  6. Nutritional composition of bioproducts generated from semi-solid ...

    African Journals Online (AJOL)

    Nutritional composition of bioproducts generated from semi-solid fermentation of pineapple peel by edible mushrooms. Raiane Áila Teixeira Souza, Tamiris Rio Branco da Fonseca, Larissa de Souza Kirsch, Larissa Svetlana Cavalcante Silva, Mircella Marialva Alecrim, Raimundo Felipe da Cruz Filho, Maria Francisca ...

  7. Study of the microstructural evolution and rheological behavior by semisolid compression between parallel plate of the alloy A356 solidified under a continuously rotating magnetic field

    International Nuclear Information System (INIS)

    Leiva L, Ricardo; Sanchez V, Cristian; Mannheim C, Rodolfo; Bustos C, Oscar

    2004-01-01

    This work presents a study of the rheological behavior of the alloy A356, with and without continuous magnetic agitation during its solidification, in semisolid state. The evaluation was performed using a parallel plate compression rheometer with the digital recording of position and time data. The microstructural evolution was also studied at the start and end of the semisolid compression test. The procedure involved tests of short cylinders extracted from billets with a non dendritic microstructure cast under a continuously rotating magnetic field. These pieces were tested in different solid fractions, at constant charges and at constant deformation velocities. When the test is carried out at a constant charge the equation can be determined that governs the rheological behavior of the material in semisolid state following a power grade of two Ostwald-de-Waele parameters. But when the test is done at a constant deformation speed the flow behavior of the material can be described in the semisolid shaping process. The results obtained show that the morphology of the phases present in the microstructure is highly relevant to its rheological behavior. A globular coalesced rosette to rosette type microstructure was found to have the typical behavior of a fluid when shaped in a semisolid state but a cast dendritic structure did not behave this way. Also the Arrhenius type dependence of viscosity with temperature was established (CW)

  8. Simulation of Semi-Solid Material Mechanical Behavior Using a Combined Discrete/Finite Element Method

    Science.gov (United States)

    Sistaninia, M.; Phillion, A. B.; Drezet, J.-M.; Rappaz, M.

    2011-01-01

    As a necessary step toward the quantitative prediction of hot tearing defects, a three-dimensional stress-strain simulation based on a combined finite element (FE)/discrete element method (DEM) has been developed that is capable of predicting the mechanical behavior of semisolid metallic alloys during solidification. The solidification model used for generating the initial solid-liquid structure is based on a Voronoi tessellation of randomly distributed nucleation centers and a solute diffusion model for each element of this tessellation. At a given fraction of solid, the deformation is then simulated with the solid grains being modeled using an elastoviscoplastic constitutive law, whereas the remaining liquid layers at grain boundaries are approximated by flexible connectors, each consisting of a spring element and a damper element acting in parallel. The model predictions have been validated against Al-Cu alloy experimental data from the literature. The results show that a combined FE/DEM approach is able to express the overall mechanical behavior of semisolid alloys at the macroscale based on the morphology of the grain structure. For the first time, the localization of strain in the intergranular regions is taken into account. Thus, this approach constitutes an indispensible step towards the development of a comprehensive model of hot tearing.

  9. Process for the disposal of alkali metals

    International Nuclear Information System (INIS)

    Lewis, L.C.

    1979-01-01

    The invention describes a method of disposing of alkali metals by forming a solid waste for storage. The method comprises preparing an aqueous disposal solution of at least 55 weight percent alkali metal hydroxide, heating the alkali metal to melting temperature to form a feed solution, and spraying the molten feed solution into the disposal solution. The alkali metal reacts with the water in the disposal solution in a controlled reaction which produces alkali metal hydroxide, hydrogen and heat and thereby forms a solution of alkali metal hydroxides. Water is added to the solution in amounts sufficient to maintain the concentration of alkali metal hydroxides in the solution at 70 to 90 weight percent, and to maintain the temperature of the solution at about the boiling point. Removing and cooling the alkali metal hydroxide solution thereby forms a solid waste for storage. The method is particularly applicable to radioactive alkali metal reactor coolant. (auth)

  10. Metal processing with ultrashort laser pulses

    Science.gov (United States)

    Banks, Paul S.; Felt, M. D.; Komashko, Aleksey M.; Perry, Michael D.; Rubenchik, Alexander M.; Stuart, Brent C.

    2000-08-01

    Femtosecond laser ablation has been shown to produce well-defined cuts and holes in metals with minimal heat effect to the remaining material. Ultrashort laser pulse processing shows promise as an important technique for materials processing. We will discuss the physical effects associated with processing based experimental and modeling results. Intense ultra-short laser pulse (USLP) generates high pressures and temperatures in a subsurface layer during the pulse, which can strongly modify the absorption. We carried out simulations of USLP absorption versus material and pulse parameters. The ablation rate as function of the laser parameters has been estimated. Since every laser pulse removes only a small amount of material, a practical laser processing system must have high repetition rate. We will demonstrate that planar ablation is unstable and the initially smooth crater bottom develops a corrugated pattern after many tens of shots. The corrugation growth rate, angle of incidence and the polarization of laser electric field dependence will be discussed. In the nonlinear stage, the formation of coherent structures with scales much larger than the laser wavelength was observed. Also, there appears to be a threshold fluence above which a narrow, nearly perfectly circular channel forms after a few hundred shots. Subsequent shots deepen this channel without significantly increasing its diameter. The role of light absorption in the hole walls will be discussed.

  11. Laser Processing of Metals and Polymers

    Energy Technology Data Exchange (ETDEWEB)

    Singaravelu, Senthilraja [Old Dominion Univ., Norfolk, VA (United States)

    2012-05-01

    A laser offers a unique set of opportunities for precise delivery of high quality coherent energy. This energy can be tailored to alter the properties of material allowing a very flexible adjustment of the interaction that can lead to melting, vaporization, or just surface modification. Nowadays laser systems can be found in nearly all branches of research and industry for numerous applications. Sufficient evidence exists in the literature to suggest that further advancements in the field of laser material processing will rely significantly on the development of new process schemes. As a result they can be applied in various applications starting from fundamental research on systems, materials and processes performed on a scientific and technical basis for the industrial needs. The interaction of intense laser radiation with solid surfaces has extensively been studied for many years, in part, for development of possible applications. In this thesis, I present several applications of laser processing of metals and polymers including polishing niobium surface, producing a superconducting phase niobium nitride and depositing thin films of niobium nitride and organic material (cyclic olefin copolymer). The treated materials were examined by scanning electron microscopy (SEM), electron probe microanalysis (EPMA), atomic force microscopy (AFM), high resolution optical microscopy, surface profilometry, Fourier transform infrared spectroscopy (FTIR) and x-ray diffraction (XRD). Power spectral density (PSD) spectra computed from AFM data gives further insight into the effect of laser melting on the topography of the treated niobium.

  12. Catalytic extraction processing of contaminated scrap metal

    Energy Technology Data Exchange (ETDEWEB)

    Griffin, T.P.; Johnston, J.E.; Payea, B.M. [Molten Metal Technology, Inc., Waltham, MA (United States)] [and others

    1995-10-01

    The U.S. Department of Energy issued a Planned Research and Development Announcement (PRDA) in 1993, with the objective of identifying unique technologies which could be applied to the most hazardous waste streams at DOE sites. The combination of radioactive contamination with additional contamination by hazardous constituents such as those identified by the Resource Conservation and Recovery Act (RCRA) pose an especially challenging problem. Traditional remediation technologies are increasingly becoming less acceptable to stakeholders and regulators because of the risks they pose to public health and safety. Desirable recycling technologies were described by the DOE as: (1) easily installed, operated, and maintained; (2) exhibiting superior environmental performance; (3) protective of worker and public health and safety; (4) readily acceptable to a wide spectrum of evaluators; and (5) economically feasible. Molten Metal Technology, Inc. (MMT) was awarded a contract as a result of the PRDA initiative to demonstrate the applicability of Catalytic Extraction Processing (CEP), MMT`s proprietary elemental recycling technology, to DOE`s inventory of low level mixed waste. This includes DOE`s inventory of radioactively- and RCRA-contaminated scrap metal and other waste forms expected to be generated by the decontamination and decommissioning (D&D) of DOE sites.

  13. Catalytic extraction processing of contaminated scrap metal

    International Nuclear Information System (INIS)

    Griffin, T.P.; Johnston, J.E.; Payea, B.M.

    1995-01-01

    The U.S. Department of Energy issued a Planned Research and Development Announcement (PRDA) in 1993, with the objective of identifying unique technologies which could be applied to the most hazardous waste streams at DOE sites. The combination of radioactive contamination with additional contamination by hazardous constituents such as those identified by the Resource Conservation and Recovery Act (RCRA) pose an especially challenging problem. Traditional remediation technologies are increasingly becoming less acceptable to stakeholders and regulators because of the risks they pose to public health and safety. Desirable recycling technologies were described by the DOE as: (1) easily installed, operated, and maintained; (2) exhibiting superior environmental performance; (3) protective of worker and public health and safety; (4) readily acceptable to a wide spectrum of evaluators; and (5) economically feasible. Molten Metal Technology, Inc. (MMT) was awarded a contract as a result of the PRDA initiative to demonstrate the applicability of Catalytic Extraction Processing (CEP), MMT's proprietary elemental recycling technology, to DOE's inventory of low level mixed waste. This includes DOE's inventory of radioactively- and RCRA-contaminated scrap metal and other waste forms expected to be generated by the decontamination and decommissioning (D ampersand D) of DOE sites

  14. Research progress on microstructure evolution of semi-solid aluminum alloys in ultrasonic field and their rheocasting

    Directory of Open Access Journals (Sweden)

    Wu Shusen

    2014-07-01

    Full Text Available The effects of ultrasonic vibration (UV treatment on microstructure of semi-solid aluminum alloys and the application of UV in rheocasting process are reviewed. Good semi-solid slurry can be produced by high-intensity UV process for aluminum alloys. The microstructures of Al-Si, Al-Mg and Al-Cu alloys produced by rheocasting assisted with UV are compact and with fine grains. The mechanical properties of the UV treated alloys are increased by about 20%-30%. Grain refinement of the alloys is generally considered because of cavitation and acoustic streaming caused by UV. Apart from these mechanisms, a hypothesis of the fuse of dendrite root caused by capillary infiltration in the ultrasonic field, as well as a mechanism of crystallites falling off from the mould-wall and crystal multiplication by mechanical vibration effect in indirect ultrasonic vibration are proposed to explain the microstructure evolution of the alloys.

  15. Microstructural evolution and thixoformability of semi-solid aluminum 319s alloy during re-melting

    International Nuclear Information System (INIS)

    Hu, X.G.; Zhu, Q.; Lu, H.X.; Zhang, F.; Li, D.Q.; Midson, S.P.

    2015-01-01

    The aim of this paper is to characterize both microstructural evolution and thixoformability during partial melting of semi-solid 319s alloy. The thixoformability criteria of 319s was initially investigated by thermodynamic analysis. In-situ observation of partial re-melting was performed by a Confocal Laser Scanning Microscope to determine the effect of heating rate on melting characteristics. Meanwhile, the microstructural evolution of 319s alloy at extremely low heating rate was also investigated in order to understand the mechanism of re-melting process. The studies demonstrated that 319s alloy is suitable for thixocasting because of the controllable liquid fraction in the operating window of 15 °C. The process window was effected by both temperature and heating time. The primary particles evolution in 319s alloy can be divided into four stages, and the coarsening rate during isothermal test is 227 μm 3 /s. The effective method to obtain desirable microstructure is to manage the time in the semi-solid state by controlling heating rate and soaking time. - Highlights: • The thixoformability of 319s is discussed by using SPSC and thermodynamic analysis. • The re-melting processes at different heating rate are in-situ observed. • We identified the four stages of microstructural evolution during re-melting. • The coarsening rate K for 319s during isothermal test is identified. • The variation tendency of Si particle size with increasing time is reported

  16. Process for the enhanced capture of heavy metal emissions

    Science.gov (United States)

    Biswas, Pratim; Wu, Chang-Yu

    2001-01-01

    This invention is directed to a process for forming a sorbent-metal complex. The process includes oxidizing a sorbent precursor and contacting the sorbent precursor with a metallic species. The process further includes chemically reacting the sorbent precursor and the metallic species, thereby forming a sorbent-metal complex. In one particular aspect of the invention, at least a portion of the sorbent precursor is transformed into sorbent particles during the oxidation step. These sorbent particles then are contacted with the metallic species and chemically reacted with the metallic species, thereby forming a sorbent-metal complex. Another aspect of the invention is directed to a process for forming a sorbent metal complex in a combustion system. The process includes introducing a sorbent precursor into a combustion system and subjecting the sorbent precursor to an elevated temperature sufficient to oxidize the sorbent precursor and transform the sorbent precursor into sorbent particles. The process further includes contacting the sorbent particles with a metallic species and exposing the sorbent particles and the metallic species to a complex-forming temperature whereby the metallic species reacts with the sorbent particles thereby forming a sorbent-metal complex under UV irradiation.

  17. Development of rheometer for semi-solid highmelting point alloys

    Directory of Open Access Journals (Sweden)

    LIU Wen

    2005-11-01

    Full Text Available A rheometer for semi-solid high-melting point alloys was developed based on the principle of a double-bucket rheometer, with which the solidifying of semi-solid high-melting point alloy melt could be effectively controlled by the control of temperature and the outer force-field; and different microstructures have also been obtained. This rheometer can be used to investigate the rheological behavior under different conditions by changing the Theological parameters. By way of full-duplex communication between the computer and each sensor, automatic control of the test equipment and real- timemeasurement of rheological parameters were realized. Finally, the influencing factors on torque are also quantitatively analyzed.

  18. Effect of temperature on viscoelastic properties of semisolid dairy desserts

    OpenAIRE

    Tárrega, Amparo; Durán, Luis; Costell, Elvira

    2003-01-01

    The “natillas”, semisolid dairy dessert of wide consumption in Spain, is composed of milk, starch, hydrocolloids, sugars, colorants and aromas. The particular characteristics of some ingredients, like fat content of milk, type of starch, and/or type and concentration of hydrocolloids, and their crossed interactions, will be reflected in notable differences in their rheological and sensory properties. Little information is available on the differences to be found in commercial samples of this ...

  19. Effects Of Thermal Exchange On Material Flow During Steel Thixoextrusion Process

    International Nuclear Information System (INIS)

    Becker, Eric; Gu Guochao; Langlois, Laurent; Bigot, Regis; Pesci, Raphael

    2011-01-01

    Semisolid processing is an innovative technology for near net-shape production of components, where the metallic alloys are processed in the semisolid state. Taking advantage of the thixotropic behavior of alloys in the semisolid state, significant progress has been made in semisolid processing. However, the consequences of such behavior on the flow during thixoforming are still not completely understood. To explore and better understand the influence of the different parameters on material flow during thixoextrusion process, thixoextrusion experiments were performed using the low carbon steel C38. The billet was partially melted at high solid fraction. Effects of various process parameters including the initial billet temperature, the temperature of die, the punch speed during process and the presence of a Ceraspray layer at the interface of tool and billet were investigated through experiments and simulation. After analyzing the results thus obtained, it was identified that the aforementioned parameters mainly affect thermal exchanges between die and part. The Ceraspray layer not only plays a lubricant role, but also acts as a thermal barrier at the interface of tool and billet. Furthermore, the thermal effects can affect the material flow which is composed of various distinct zones.

  20. Process to separate alkali metal salts from alkali metal reacted hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Gordon, John Howard; Alvare, Javier; Larsen, Dennis; Killpack, Jeff

    2017-06-27

    A process to facilitate gravimetric separation of alkali metal salts, such as alkali metal sulfides and polysulfides, from alkali metal reacted hydrocarbons. The disclosed process is part of a method of upgrading a hydrocarbon feedstock by removing heteroatoms and/or one or more heavy metals from the hydrocarbon feedstock composition. This method reacts the oil feedstock with an alkali metal and an upgradant hydrocarbon. The alkali metal reacts with a portion of the heteroatoms and/or one or more heavy metals to form an inorganic phase containing alkali metal salts and reduced heavy metals, and an upgraded hydrocarbon feedstock. The inorganic phase may be gravimetrically separated from the upgraded hydrocarbon feedstock after mixing at a temperature between about 350.degree. C. to 400.degree. C. for a time period between about 15 minutes and 2 hours.

  1. Noble Metal/Ceramic Composites in Flame Processes

    DEFF Research Database (Denmark)

    Schultz, Heiko; Madler, Lutz; Strobel, Reto

    conditions influence the resulting noble metal particles size in those systems [1]. For every specific application the particle size and the metal/metal oxide interaction affect the performance of these nano-composite materials [2]. Recently, aerosol processes have been successfully used to produce platinum...

  2. Application of Hydroforming Process in Sheet Metal Formation

    OpenAIRE

    GRIZELJ, Branko; CUMIN, Josip; ERGIĆ, Todor

    2009-01-01

    This article deals with the theory and application of a hydroforming process. Nowadays automobile manufacturers use high strength sheet metal plates. This high strength steel sheet metal plates are strain hardened in the process of metal forming. With the use of high strength steel, cars are made lightweight, which is intended for low fuel consumption because of high energy prices. Some examples of application of a hydroforming process are simulated with FEM.

  3. Process for the disposal of alkali metals

    International Nuclear Information System (INIS)

    Lewis, L.C.

    1977-01-01

    Large quantities of alkali metals may be safely reacted for ultimate disposal by contact with a hot concentrated caustic solution. The alkali metals react with water in the caustic solution in a controlled reaction while steam dilutes the hydrogen formed by the reaction to a safe level. 6 claims

  4. Low-level radioactive waste from rare metals processing facilities

    International Nuclear Information System (INIS)

    Eng, J.; Hendricks, D.W.; Feldman, J.; Giardina, P.A.

    1980-01-01

    This paper reviews the situations at the existing Teledyne Wah Chang Co., Inc. located at Albany, Oregon, and the former Carborundum Corp./Amax Specialty Metals, Inc., facilities located at Parkersburg, West Virginia, and Akron, New York, in order to show the extent of the radioactivity problem at rare metals processing facilities and the need to identify for radiological review other rare metal and rare earth processing sites

  5. Antipollution processing of a used refining catalyst and metal recovery

    Energy Technology Data Exchange (ETDEWEB)

    Trinh Dinh Chan; Llido, E.

    1992-04-30

    The used catalyst, containing metals such as vanadium, nickel and iron, is unloaded from the plant and is first processed by stripping; it is then calcined in critical conditions, and the catalyst metals are leached with a sodium hydroxide or sodium carbonate aqueous solution. The antipollution process can be applied to oil fraction hydroconversion or hydroprocessing catalysts.

  6. High-Speed Synchrotron X-ray Imaging Studies of the Ultrasound Shockwave and Enhanced Flow during Metal Solidification Processes

    Science.gov (United States)

    Tan, Dongyue; Lee, Tung Lik; Khong, Jia Chuan; Connolley, Thomas; Fezzaa, Kamel; Mi, Jiawei

    2015-07-01

    The highly dynamic behavior of ultrasonic bubble implosion in liquid metal, the multiphase liquid metal flow containing bubbles and particles, and the interaction between ultrasonic waves and semisolid phases during solidification of metal were studied in situ using the complementary ultrafast and high-speed synchrotron X-ray imaging facilities housed, respectively, at the Advanced Photon Source, Argonne National Laboratory, US, and Diamond Light Source, UK. Real-time ultrafast X-ray imaging of 135,780 frames per second revealed that ultrasonic bubble implosion in a liquid Bi-8 wt pctZn alloy can occur in a single wave period (30 kHz), and the effective region affected by the shockwave at implosion was 3.5 times the original bubble diameter. Furthermore, ultrasound bubbles in liquid metal move faster than the primary particles, and the velocity of bubbles is 70 ~ 100 pct higher than that of the primary particles present in the same locations close to the sonotrode. Ultrasound waves can very effectively create a strong swirling flow in a semisolid melt in less than one second. The energetic flow can detach solid particles from the liquid-solid interface and redistribute them back into the bulk liquid very effectively.

  7. Reproducibility of esophageal scintigraphy using semi-solid yoghurt

    Energy Technology Data Exchange (ETDEWEB)

    Imai, Yukinori; Kinoshita, Manabu; Asakura, Yasushi; Kakinuma, Tohru; Shimoji, Katsunori; Fujiwara, Kenji; Suzuki, Kenji; Miyamae, Tatsuya [Saitama Medical School, Moroyama (Japan)

    1999-10-01

    Esophageal scintigraphy is a non-invasive method which evaluate esophageal function quantitatively. We applied new technique using semi-solid yoghurt, which can evaluate esophageal function in a sitting position. To evaluate the reproducibility of this method, scintigraphy were performed in 16 healthy volunteers. From the result of four swallows except the first one, the mean coefficients of variation in esophageal transit time and esophageal emptying time were 12.8% and 13.4% respectively (interday variation). As regards the interday variation, this method had also good reproducibility from the result on the 2 separate days. (author)

  8. Semisolid forming of 44MnSiV6 microalloyed steel

    Science.gov (United States)

    Plata, Gorka; Lozares, Jokin; Hurtado, Iñaki; Azpilgain, Zigor; Idoyaga, Zuriñe

    2018-05-01

    Globalisation is forcing many sectors to be more cost-effective due to the low manpower cost of developing countries. This, in combination with European trends of green production and reduction of emissions, enhances the necessity of advanced technologies to remain at the forefront of the market. It is precisely in this field where the Semisolid forming (SSF) exhibits a great potential. In Mondragon Unibertsitatea, it has been demonstrated the capability of producing sound components of 42CrMo4 and S48C steels by saving material, energy and attaining as hot forged properties. To make the process even more cost-effective, it has also been proved the capacity of SSF 44MnSiV6 microalloyed steel that enables the striking of the post processing heat treatment.

  9. Manufacturing processes of cellular metals. Part I. Liquid route processes

    International Nuclear Information System (INIS)

    Fernandez, P.; Cruz, L. J.; Coleto, J.

    2008-01-01

    With its interesting and particular characteristics, cellular metals are taking part of the great family of new materials. They can have open or closed porosity. At the present time, the major challenge for the materials researchers is based in the manufacturing techniques improvement in order to obtain reproducible and reliable cellular metals with quality. In the present paper, the different production methods to manufacture cellular metals by liquid route are reviewed; making a short description about the main parameters involved and the advantages and drawbacks in each of them. (Author) 106 refs

  10. Separation of Metals From Spent Catalysts Waste by Bioleaching Process

    OpenAIRE

    Sirin Fairus, Tria Liliandini, M.Febrian, Ronny Kurniawan

    2010-01-01

    A kind of waste that hard to be treated is a metal containing solid waste. Leaching method is one thealternative waste treatment. But there still left an obstacle on this method, it is the difficulty to find theselective solvent for the type of certain metal that will separated. Bioleaching is one of the carry ablealternative waste treatments to overcome that obstacle. Bioleaching is a metal dissolving process orextraction from a sediment become dissolve form using microorganisms. On this met...

  11. Method of processing radioactive metallic sodium with recycling alcohols

    International Nuclear Information System (INIS)

    Sakai, Takuhiko; Mitsuzuka, Norimasa.

    1980-01-01

    Purpose: To employ high safety alcohol procession and decrease the amount of wastes in the procession of radioactive metallic sodium discharged from LMFBR type reactors. Method: Radioactive metallic sodium containing long half-decay period nuclides such as cesium, strontium, barium, cerium, lanthanum or zirconium is dissolved in an alcohol at about 70% purity. After extracting the sodium alcoholate thus formed, gaseous hydrochloride is blown-in to separate the sodium alcoholate into alcohol and sodium chloride, and regenerated alcohol is used again for dissolving sodium metal. The sodium chloride thus separated is processed into solid wastes. (Furukawa, Y.)

  12. A bioseparation process for removing heavy metals from waste ...

    African Journals Online (AJOL)

    The role of cell structure, cell wall, micropores and macropores is evaluated in terms of the potential of these biosorbents for metal sequestration. Binding mechanisms are discussed, including the key functional groups involved and the ion-exchange process. Quantification of metal-biomass interactions is fundamental to the ...

  13. Time evolution of absorption process in nonlinear metallic photonic crystals

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Mahi R.; Hatef, Ali [Department of Physics and Astronomy, University of Western Ontario, London (Canada)

    2009-05-15

    The time evolution of the absorption coefficient in metallic photonic crystals has been studied numerically. These crystals are made from metallic spheres which are arranged periodically in air. The refractive index of the metallic spheres depends on the plasma frequency. Probe and pump fields are applied to monitor the absorption process. Ensembles of three-level particles are embedded in the crystal. Nanoparticles are interacting with the metallic crystals via the electron-photon interaction. It is found that when the resonance states lie away from the band edges system goes to transparent state. (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  14. Determination of reduction yield of lithium metal reduction process

    International Nuclear Information System (INIS)

    Choi, In Kyu; Cho, Young Hwan; Kim, Taek Jin; Jee, Kwang Young

    2004-01-01

    Metal reduction of spent oxide fuel is the first step for the effective storage of spent fuel in Korea as well as transmutation purpose of long-lived radio-nuclides. During the reduction of uranium oxide by lithium metal to uranium metal, lithium oxide is stoichiometrically produced. By determining the concentration of lithium oxide in lithium chloride, we can estimate that how much uranium oxide is converted to uranium metal. Previous method to determine the lithium oxide concentration in lithium chloride is tedious and timing consuming. This paper describe the on-line monitoring method of lithium oxide during the reduction process

  15. PROCESSING OF URANIUM-METAL-CONTAINING FUEL ELEMENTS

    Science.gov (United States)

    Moore, R.H.

    1962-10-01

    A process is given for recovering uranium from neutronbombarded uranium- aluminum alloys. The alloy is dissolved in an aluminum halide--alkali metal halide mixture in which the halide is a mixture of chloride and bromide, the aluminum halide is present in about stoichiometric quantity as to uranium and fission products and the alkali metal halide in a predominant quantity; the uranium- and electropositive fission-products-containing salt phase is separated from the electronegative-containing metal phase; more aluminum halide is added to the salt phase to obtain equimolarity as to the alkali metal halide; adding an excess of aluminum metal whereby uranium metal is formed and alloyed with the excess aluminum; and separating the uranium-aluminum alloy from the fission- productscontaining salt phase. (AEC)

  16. Process of treating surfaces of metals

    International Nuclear Information System (INIS)

    Kimura, T.; Murao, A.; Kuwahara, T.

    1975-01-01

    Both higher corrosion resistance and paint adherence are given to films formed on the surfaces of metals by treating the surfaces with aqueous solutions of one or more materials selected from the group consisting of water soluble vinyl monomer or water soluble high polymer and then irradiating with ionizing radioactive rays on the nearly dried surface film. When a water soluble inorganic compound is mixed with the above mentioned aqueous solution, the film properties are greatly improved. The inorganic ionic material should contain a cation from the group consisting of Ca, Mg, Zn, Cr, Al, Fe, and Ni. Electron beams may be used. (U.S.)

  17. Electrochemical activity of heavy metal oxides in the process of ...

    Indian Academy of Sciences (India)

    Unknown

    2002-02-02

    Feb 2, 2002 ... Electrochemical activity of heavy metal oxides in the process of chloride induced .... represents the protective barrier moderating the chloride attack which ... inhibitors and their influence on the physical properties of. Portland ...

  18. Hopper design for metallic powders used in additive manufacturing processes

    CSIR Research Space (South Africa)

    Visagie, N

    2013-10-01

    Full Text Available The influence of hopper geometry on the flow behaviour of typical metallic powders used in additive manufacturing processes is investigated. Bulk hopper theory provides a method of determining critical hopper parameters for bulk amounts...

  19. Titanium and zirconium metal powder spheroidization by thermal plasma processes

    OpenAIRE

    Bissett, H.; van der Walt, I.J.; Havenga, J.L.; Nel, J.T.

    2015-01-01

    New technologies used to manufacture high-quality components, such as direct laser sintering, require spherical powders of a narrow particle size distribution as this affects the packing density and sintering mechanism. The powder also has to be chemically pure as impurities such as H, O, C, N, and S causes brittleness, influence metal properties such as tensile strength, hardness, and ductility, and also increase surface tension during processing. Two new metal powder processes have been dev...

  20. Metal Catalyzed Fusion: Nuclear Active Environment vs. Process

    Science.gov (United States)

    Chubb, Talbot

    2009-03-01

    To achieve radiationless dd fusion and/or other LENR reactions via chemistry: some focus on environment of interior or altered near-surface volume of bulk metal; some on environment inside metal nanocrystals or on their surface; some on the interface between nanometal crystals and ionic crystals; some on a momentum shock-stimulation reaction process. Experiment says there is also a spontaneous reaction process.

  1. Sol-gel processing with inorganic metal salt precursors

    Science.gov (United States)

    Hu, Zhong-Cheng

    2004-10-19

    Methods for sol-gel processing that generally involve mixing together an inorganic metal salt, water, and a water miscible alcohol or other organic solvent, at room temperature with a macromolecular dispersant material, such as hydroxypropyl cellulose (HPC) added. The resulting homogenous solution is incubated at a desired temperature and time to result in a desired product. The methods enable production of high quality sols and gels at lower temperatures than standard methods. The methods enable production of nanosize sols from inorganic metal salts. The methods offer sol-gel processing from inorganic metal salts.

  2. Process for the regeneration of metallic catalysts

    Science.gov (United States)

    Katzer, James R.; Windawi, Hassan

    1981-01-01

    A method for the regeneration of metallic hydrogenation catalysts from the class consisting of Ni, Rh, Pd, Ir, Pt and Ru poisoned with sulfur, with or without accompanying carbon deposition, comprising subjecting the catalyst to exposure to oxygen gas in a concentration of about 1-10 ppm. intermixed with an inert gas of the group consisting of He, A, Xe, Kr, N.sub.2 and air substantially free of oxygen to an extent such that the total oxygen molecule throughout is in the range of about 10 to 20 times that of the hydrogen sulfide molecular exposure producing the catalyst poisoning while maintaining the temperature in the range of about 300.degree. to 500.degree. C.

  3. Ceramic/metal nanocomposites by lyophilization: Processing and HRTEM study

    International Nuclear Information System (INIS)

    Gutierrez-Gonzalez, C.F.; Agouram, S.; Torrecillas, R.; Moya, J.S.; Lopez-Esteban, S.

    2012-01-01

    Highlights: ► A cryogenic route has been used to obtain ceramic/metal nanostructured powders. ► The powders present good homogeneity and dispersion of metal. ► The metal nanoparticle size distributions are centred in 17–35 nm. ► Both phases, ceramic and metal, present a high degree of crystallinity. ► Good metal/ceramic interfaces due to epitaxial growth, studied by HRTEM. -- Abstract: This work describes a wet-processing route based on spray-freezing and subsequent lyophilization designed to obtain nanostructured ceramic/metal powders. Starting from the ceramic powder and the corresponding metal salt, a water-based suspension is sprayed on liquid nitrogen. The frozen powders are subsequently freeze-dried, calcined and reduced. The material was analyzed using X-ray diffraction analysis at all stages. High resolution transmission electron microscopy studies showed a uniform distribution of metal nanoparticles on the ceramic grain surfaces, good interfaces and high crystallinity, with an average metal particle size in the nanometric range.

  4. Studies on the optimization of deformation processed metal metal matrix composites

    Energy Technology Data Exchange (ETDEWEB)

    Ellis, Tim W. [Iowa State Univ., Ames, IA (United States)

    1994-01-04

    A methodology for the production of deformation processed metal metal matrix composites from hyper-eutectic copper-chromium alloys was developed. This methodology was derived from a basic study of the precipitation phenomena in these alloys encompassing evaluation of microstructural, electrical, and mechanical properties. The methodology developed produces material with a superior combination of electrical and mechanical properties compared to those presently available in commercial alloys. New and novel alloying procedures were investigated to extend the range of production methods available for these material. These studies focused on the use of High Pressure Gas Atomization and the development of new containment technologies for the liquid alloy. This allowed the production of alloys with a much more refined starting microstructure and lower contamination than available by other methods. The knowledge gained in the previous studies was used to develop two completely new families of deformation processed metal metal matrix composites. These composites are based on immissible alloys with yttrium and magnesium matrices and refractory metal reinforcement. This work extends the physical property range available in deformation processed metal metal matrix composites. Additionally, it also represents new ways to apply these metals in engineering applications.

  5. Fabrication of subwavelength metallic structures by using a metal direct imprinting process

    International Nuclear Information System (INIS)

    Hsieh, C W; Hsiung, H Y; Lu, Y T; Sung, C K; Wang, W H

    2007-01-01

    This work employs a metal direct imprinting process, which possesses the characteristics of simplicity, low-cost and high resolution, for the fabrication of subwavelength structures on a metallic thin film. Herein, the mould featuring periodic line structures is manufactured by using E-beam lithography and followed by a dry etching process; meanwhile, the thin film is fabricated by sputtering Al on a silicon substrate. AFM section analyses are employed to measure imprinting depths of the subwavelength metallic structures and it is found that the uniformity of the imprinting depths is affected by the designed patterns, the material property of thin film and mould deformation. The process temperature and the mould filling that influence the transferred quality are investigated. In addition, TEM is also utilized to examine defects in the subwavelength metallic structures. Finally, good quality subwavelength metallic structures are fabricated under a pressure of 300 MPa for 60 s at room temperature. In this study, we have demonstrated that subwavelength metallic structures with a minimum linewidth of less than 100 nm on the Al thin film are successfully constructed by the metal direct imprinting process

  6. Application of molten salts in pyrochemical processing of reactive metals

    International Nuclear Information System (INIS)

    Mishra, B.; Olson, D.L.; Averill, W.A.

    1992-01-01

    Various mixes of chloride and fluoride salts are used as the media for conducting pyrochemical processes in the production and purification of reactive metals. These processes generate a significant amount of contaminated waste that has to be treated for recycling or disposal. Molten calcium chloride based salt systems have been used in this work to electrolytically regenerate calcium metal from calcium oxide for the in situ reduction of reactive metal oxides. The recovery of calcium is characterized by the process efficiency to overcome back reactions in the electrowinning cell. A thermodynamic analysis, based on fundamental rate theory, has been performed to understand the process parameters controlling the metal deposition, rate, behavior of the ceramic anode-sheath and influence of the back-reactions. It has been observed that the deposition of calcium is dependent on the ionic diffusion through the sheath. It has also been evidenced that the recovered calcium is completely lost through the back-reactions in the absence of a sheath. A practical scenario has also been presented where the electrowon metal can be used in situ as a reductant to reduce another reactive metal oxide

  7. Vaginal semisolid products: Technological performance considering physiologic parameters.

    Science.gov (United States)

    Machado, Rita Monteiro; Palmeira-de-Oliveira, Ana; Martinez-de-Oliveira, José; Palmeira-de-Oliveira, Rita

    2017-11-15

    Vaginal semisolid products are frequently used to treat vaginal infections and atrophy-related symptoms of menopause. Formulations composition and the methods for their characterization, especially those developed concerning the target epithelia, are key tools to predict in vivo results at early stages of product development. However, recent studies on this subject have been almost exclusively focused on anti-HIV preparations. The aim of this work consists on improving traditional characterization methods by using physiological parameters in order to construct predictive tools to characterize a new ideal vaginal semisolid formulation whatever target it may have. Ten vaginal antimicrobial and hormonal products already available in the market were studied (Gino-Canesten®, Sertopic®, Dermofix®, Gyno-pevaryl®, Lomexin®, Gino Travogen®, Dalacin V®, Ovestin®, Blissel®, Colpotrophine®). Furthermore, Universal Placebo gel and Replens® were used for comparison. Products were characterized in terms of: pH and buffering capacity in a vaginal fluid simulant (VFS); osmolality - directly and upon dilution in VFS; textural parameters (firmness, adhesiveness and bioadhesion) using vaginal ex vivo porcine epithelium; and viscosity (including VFS dilution at 37°C and after administration on an ex vivo model). Interestingly, the majority of the tested commercial vaginal formulations did not present technological characteristics close to the ideal ones when tested under target biological conditions. The inclusion of such methodologic adaptations is expected to optimize cost-efficiency of new formulations development by predicting efficacy and safety profiles at early stages of product development. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Overview of friction modelling in metal forming processes

    DEFF Research Database (Denmark)

    Nielsen, Chris Valentin; Bay, Niels Oluf

    2017-01-01

    In metal forming processes, friction between tool and workpiece is an important parameter influencing the material flow, surface quality and tool life. Theoretical models of friction in metal forming are based on analysis of the real contact area in tool-workpiece interfaces. Several research...... groups have studied and modelled the asperity flattening of workpiece material against tool surface in dry contact or in contact interfaces with only thin layers of lubrication with the aim to improve understanding of friction in metal forming. This paper aims at giving a review of the most important...... future work in order to advance further in modelling of real contact area in relation to implementation of frictional conditions existing finite element codes for simulation of metal forming processes. © 2017 The Authors. Published by Elsevier Ltd....

  9. Synthesis and processing of composites by reactive metal penetration

    Energy Technology Data Exchange (ETDEWEB)

    Loehman, R.E.; Ewsuk, K.G. [Sandia National Laboratories, Albuquerque, NM (United States); Tomsia, A.P. [Pask Research and Engineering, Berkeley, CA (United States)] [and others

    1995-05-01

    Ceramic-metal composites are being developed because their high stiffness-to weight ratios, good fracture toughness, and variable electrical and thermal properties give them advantages over more conventional materials. However, because ceramic-metal composite components presently are more expensive than monolithic materials, improvements in processing are required to reduce manufacturing costs. Reactive metal penetration is a promising new method for making ceramic- and metal-matrix composites that has the advantage of being inherently a net-shape process. This technique, once fully developed, will provide another capability for manufacturing the advanced ceramic composites that are needed for many light-weight structural and wear applications. The lower densities of these composites lead directly to energy savings in use. Near-net-shape fabrication of composite parts should lead to additional savings because costly and energy intensive grinding and machining operations are significantly reduced, and the waste generated from such finishing operations is minimized. The goals of this research program are: (1) to identify feasible compositional systems for making composites by reactive metal penetration; (2) to understand the mechanism(s) of composite formation by reactive metal penetration; and (3) to learn how to control and optimize reactive metal penetration for economical production of composites and composite coatings.

  10. Valuable metals - recovery processes, current trends, and recycling strategies

    Energy Technology Data Exchange (ETDEWEB)

    Froehlich, Peter; Lorenz, Tom; Martin, Gunther; Brett, Beate; Bertau, Martin [Institut fuer Technische Chemie, TU Bergakademie Freiberg, Leipziger Strasse 29, 09599, Freiberg (Germany)

    2017-03-01

    This Review provides an overview of valuable metals, the supply of which has been classified as critical for Europe. Starting with a description of the current state of the art, novel approaches for their recovery from primary resources are presented as well as recycling processes. The focus lies on developments since 2005. Chemistry strategies which are used in metal recovery are summarized on the basis of the individual types of deposit and mineral. In addition, the economic importance as well as utilization of the metals is outlined. (copyright 2017 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

  11. Study on Thixojoining Process Using Partial Remelting Method

    Directory of Open Access Journals (Sweden)

    M. N. Mohammed

    2013-01-01

    Full Text Available Cold-work tool steel is considered to be a nonweldable metal due to its high percentage content of carbon and alloy elements. The application of a new process of the semisolid joining of two dissimilar metals is proposed. AISI D2 cold-work tool steel was thixojoined to 304 stainless steel by using a partial remelting method. After thixojoining, microstructural examination including metallographic analysis, energy dispersive spectroscopy (EDS, and Vickers hardness tests was performed. From the results, metallographic analyses along the joint interface between semisolid AISI D2 and stainless steel showed a smooth transition from one to another and neither oxides nor microcracking was observed. Hardness values obtained from the points in the diffusion zone were much higher than those in the 304 stainless steel but lower than those in the AISI D2 tool steel. The study revealed that a new type of nonequilibrium diffusion interfacial structure was constructed at the interface of the two different types of steel. The current work successfully confirmed that avoidance of a dendritic microstructure in the semisolid joined zone and high bonding quality components can be achieved without the need for force or complex equipment when compared to conventional welding processes.

  12. Survey of electrochemical metal winning processes. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Vaaler, L.E.

    1979-03-01

    The subject program was undertaken to find electrometallurgical technology that could be developed into energy saving commercial metal winning processes. Metals whose current production processes consume significant energy (excepting copper and aluminum) are magnesium, zinc, lead, chromium, manganese, sodium, and titanium. The technology of these metals, with the exception of titanium, was reviewed. Growth of titanium demand has been too small to justify the installation of an electrolyte process that has been developed. This fact and the uncertainty of estimates of future demand dissuaded us from reviewing titanium technology. Opportunities for developing energy saving processes were found for magnesium, zinc, lead, and sodium. Costs for R and D and demonstration plants have been estimated. It appeared that electrolytic methods for chromium and manganese cannot compete energywise or economically with the pyrometallurgical methods of producing the ferroalloys, which are satisfactory for most uses of chromium and manganese.

  13. Process for removing heavy metal compounds from heavy crude oil

    Science.gov (United States)

    Cha, Chang Y.; Boysen, John E.; Branthaver, Jan F.

    1991-01-01

    A process is provided for removing heavy metal compounds from heavy crude oil by mixing the heavy crude oil with tar sand; preheating the mixture to a temperature of about 650.degree. F.; heating said mixture to up to 800.degree. F.; and separating tar sand from the light oils formed during said heating. The heavy metals removed from the heavy oils can be recovered from the spent sand for other uses.

  14. Process control for sheet-metal stamping process modeling, controller design and shop-floor implementation

    CERN Document Server

    Lim, Yongseob; Ulsoy, A Galip

    2014-01-01

    Process Control for Sheet-Metal Stamping presents a comprehensive and structured approach to the design and implementation of controllers for the sheet metal stamping process. The use of process control for sheet-metal stamping greatly reduces defects in deep-drawn parts and can also yield large material savings from reduced scrap. Sheet-metal forming is a complex process and most often characterized by partial differential equations that are numerically solved using finite-element techniques. In this book, twenty years of academic research are reviewed and the resulting technology transitioned to the industrial environment. The sheet-metal stamping process is modeled in a manner suitable for multiple-input multiple-output control system design, with commercially available sensors and actuators. These models are then used to design adaptive controllers and real-time controller implementation is discussed. Finally, experimental results from actual shopfloor deployment are presented along with ideas for further...

  15. Development of Metal Plate with Internal Structure Utilizing the Metal Injection Molding (MIM Process

    Directory of Open Access Journals (Sweden)

    Kwangho Shin

    2013-12-01

    Full Text Available In this study, we focus on making a double-sided metal plate with an internal structure, such as honeycomb. The stainless steel powder was used in the metal injection molding (MIM process. The preliminary studies were carried out for the measurement of the viscosity of the stainless steel feedstock and for the prediction of the filling behavior through Computer Aided Engineering (CAE simulation. PE (high density polyethylene (HDPE and low density polyethylene (LDPE and polypropylene (PP resins were used to make the sacrificed insert with a honeycomb structure using a plastic injection molding process. Additionally, these sacrificed insert parts were inserted in the metal injection mold, and the metal injection molding process was carried out to build a green part with rectangular shape. Subsequently, debinding and sintering processes were adopted to remove the sacrificed polymer insert. The insert had a suitable rigidity that was able to endure the filling pressure. The core shift analysis was conducted to predict the deformation of the insert part. The 17-4PH feedstock with a low melting temperature was applied. The glass transition temperature of the sacrificed polymer insert would be of a high grade, and this insert should be maintained during the MIM process. Through these processes, a square metal plate with a honeycomb structure was made.

  16. Solution processed metal oxide thin film hole transport layers for high performance organic solar cells

    Science.gov (United States)

    Steirer, K. Xerxes; Berry, Joseph J.; Chesin, Jordan P.; Lloyd, Matthew T.; Widjonarko, Nicodemus Edwin; Miedaner, Alexander; Curtis, Calvin J.; Ginley, David S.; Olson, Dana C.

    2017-01-10

    A method for the application of solution processed metal oxide hole transport layers in organic photovoltaic devices and related organic electronics devices is disclosed. The metal oxide may be derived from a metal-organic precursor enabling solution processing of an amorphous, p-type metal oxide. An organic photovoltaic device having solution processed, metal oxide, thin-film hole transport layer.

  17. Texture and mouthfeel of semi-solid foods : commercial mayonnaises, dressings, custard desserts and warm sauces

    NARCIS (Netherlands)

    Weenen, H.; Gemert, van L.J.; Doorn, van J.M.; Dijksterhuis, G.B.; Wijk, de R.A.

    2003-01-01

    Texture and mouthfeel sensations of three groups of semisolid foodstuffs (mayonnaises and dressings, custard desserts and warm sauces) were characterised, measured, evaluated and compared based on quantitative descriptive sensory analysis of commercial products. Six groups of texture attributes were

  18. Texture and mouthfeel of semisolid foods: Commercial mayonnaises, dressings, custard desserts and warm sauces

    NARCIS (Netherlands)

    Weenen, H.; Gemert, L.J. van; Doorn, J.M. van; Dijksterhuis, G.B.; Wijk, R.A. de

    2003-01-01

    Texture and mouthfeel sensations of three groups of semisolid foodstuffs (mayonnaises and dressings, custard desserts and warm sauces) were characterised, measured, evaluated and compared based on quantitative descriptive sensory analysis of commercial products. Six groups of texture attributes were

  19. Comparative study of resist stabilization techniques for metal etch processing

    Science.gov (United States)

    Becker, Gerry; Ross, Matthew F.; Wong, Selmer S.; Minter, Jason P.; Marlowe, Trey; Livesay, William R.

    1999-06-01

    This study investigates resist stabilization techniques as they are applied to a metal etch application. The techniques that are compared are conventional deep-UV/thermal stabilization, or UV bake, and electron beam stabilization. The electron beam tool use din this study, an ElectronCure system from AlliedSignal Inc., ELectron Vision Group, utilizes a flood electron source and a non-thermal process. These stabilization techniques are compared with respect to a metal etch process. In this study, two types of resist are considered for stabilization and etch: a g/i-line resist, Shipley SPR-3012, and an advanced i-line, Shipley SPR 955- Cm. For each of these resist the effects of stabilization on resist features are evaluated by post-stabilization SEM analysis. Etch selectivity in all cases is evaluated by using a timed metal etch, and measuring resists remaining relative to total metal thickness etched. Etch selectivity is presented as a function of stabilization condition. Analyses of the effects of the type of stabilization on this method of selectivity measurement are also presented. SEM analysis was also performed on the features after a compete etch process, and is detailed as a function of stabilization condition. Post-etch cleaning is also an important factor impacted by pre-etch resist stabilization. Results of post- etch cleaning are presented for both stabilization methods. SEM inspection is also detailed for the metal features after resist removal processing.

  20. [Exposure to metal compounds in occupational galvanic processes].

    Science.gov (United States)

    Surgiewicz, Jolanta; Domański, Wojciech

    2006-01-01

    Occupational galvanic processes are provided in more than 600 small and medium enterprises in Poland. Workers who deal with galvanic coating are exposed to heavy metal compounds: tin, silver, copper and zinc. Some of them are carcinogenic, for example, hexavalent chromium compounds, nickel and cadmium compounds. Research covered several tens of workstations involved in chrome, nickel, zinc, tin, silver, copper and cadmium plating. Compounds of metals present in the air were determined: Cr, Ni, Cd, Sn, Ag--by atomic absorption spectrometry with electrothermal atomization (ET-AAS) and Zn--by atomic absorption spectrometry with flame atomization (F-AAS). The biggest metal concentrations--of silver and copper--were found at workstations of copper, brass, cadmium, nickel and chrome plating, conducted at the same time. Significant concentrations of copper were found at workstations of maintenance bathing and neutralizing of sewage. The concentrations of metals did not exceed Polish MAC values. MAC values were not exceeded for carcinogenic chromium(VI), nickel or cadmium, either. In galvanic processes there was no hazard related to single metals or their compounds, even carcinogenic ones. Combined exposure indicators for metals at each workstation did not exceed 1, either. However, if there are even small quantities of carcinogenic agents, health results should always be taken into consideration.

  1. Semi-solid electrode cell having a porous current collector and methods of manufacture

    Science.gov (United States)

    Chiang, Yet-Ming; Carter, William Craig; Cross, III, James C.; Bazzarella, Ricardo; Ota, Naoki

    2017-11-21

    An electrochemical cell includes an anode, a semi-solid cathode, and a separator disposed therebetween. The semi-solid cathode includes a porous current collector and a suspension of an active material and a conductive material disposed in a non-aqueous liquid electrolyte. The porous current collector is at least partially disposed within the suspension such that the suspension substantially encapsulates the porous current collector.

  2. Preliminary investigations of the copper/bismuth/tin system in a proposed new net-shaping process

    International Nuclear Information System (INIS)

    Macnamara, D.S.; Meltcalfe, R.D.; Krezalek, I.

    2002-01-01

    Full text: Mixed-phase near net-shape forming processes such as semi-solid and thixotropic moulding are receiving increasing interest. Problems met in these processes include homogenisation of the semi-solid melt and temperature control in the semi-solid region. Injection moulding of a paste of solid particles of relatively high melting point in a liquid metal matrix removes the need for precision temperature control. Ideally the process should also require neither mechanical stirring nor agitation. In this project, powder precursors are subjected to uniaxial compaction to improve particle distribution and provide good metal-to-metal contact. Static heating tests to determine the composition of the mixed-phase melt and dynamic tests to investigate the homogeneity, density and net shape of extruded samples have been carried out. Initial investigations have concentrated on copper particles suspended in a near-eutectic bismuth-tin alloy. This provides a good density match between liquid and solid phases, a low temperature melt, and good optical contrast for traditional metallography. We used the scanning electron microscope to highlight fine detail of microstructural features, and electron probe microanalysis for compositional information on the resultant material. Detailed results are presented. Copyright (2002) Australian Society for Electron Microscopy Inc

  3. Novel forward osmosis process to effectively remove heavy metal ions

    KAUST Repository

    Cui, Yue; Ge, Qingchun; Liu, Xiangyang; Chung, Neal Tai-Shung

    2014-01-01

    In this study, a novel forward osmosis (FO) process for the removal of heavy metal ions from wastewater was demonstrated for the first time. The proposed FO process consists of a thin-film composite (TFC) FO membrane made from interfacial polymerization on a macrovoid-free polyimide support and a novel bulky hydroacid complex Na4[Co(C6H4O7)2]·r2H2O (Na-Co-CA) as the draw solute to minimize the reverse solute flux. The removal of six heavy metal solutions, i.e., Na2Cr2O7, Na2HAsO4, Pb(NO3)2, CdCl2, CuSO4, Hg(NO3)2, were successfully demonstrated. Water fluxes around 11L/m2/h (LMH) were harvested with heavy metals rejections of more than 99.5% when employing 1M Na-Co-CA as the draw solution to process 2000ppm(1 ppm=1 mg/L) heavy metal solutions at room temperature. This FO performance outperforms most nanofiltration (NF) processes. In addition, the high rejections were maintained at 99.5% when a more concentrated draw solution (1.5M) or feed solution (5000ppm) was utilized. Furthermore, rejections greater than 99.7% were still achieved with an enhanced water flux of 16.5LMH by operating the FO process at 60°C. The impressive heavy metal rejections and satisfactory water flux under various conditions suggest great potential of the newly developed FO system for the treatment of heavy metal wastewater. © 2014 Elsevier B.V.

  4. Novel forward osmosis process to effectively remove heavy metal ions

    KAUST Repository

    Cui, Yue

    2014-10-01

    In this study, a novel forward osmosis (FO) process for the removal of heavy metal ions from wastewater was demonstrated for the first time. The proposed FO process consists of a thin-film composite (TFC) FO membrane made from interfacial polymerization on a macrovoid-free polyimide support and a novel bulky hydroacid complex Na4[Co(C6H4O7)2]·r2H2O (Na-Co-CA) as the draw solute to minimize the reverse solute flux. The removal of six heavy metal solutions, i.e., Na2Cr2O7, Na2HAsO4, Pb(NO3)2, CdCl2, CuSO4, Hg(NO3)2, were successfully demonstrated. Water fluxes around 11L/m2/h (LMH) were harvested with heavy metals rejections of more than 99.5% when employing 1M Na-Co-CA as the draw solution to process 2000ppm(1 ppm=1 mg/L) heavy metal solutions at room temperature. This FO performance outperforms most nanofiltration (NF) processes. In addition, the high rejections were maintained at 99.5% when a more concentrated draw solution (1.5M) or feed solution (5000ppm) was utilized. Furthermore, rejections greater than 99.7% were still achieved with an enhanced water flux of 16.5LMH by operating the FO process at 60°C. The impressive heavy metal rejections and satisfactory water flux under various conditions suggest great potential of the newly developed FO system for the treatment of heavy metal wastewater. © 2014 Elsevier B.V.

  5. A new insight into high-strength Ti62Nb12.2Fe13.6Co6.4Al5.8 alloys with bimodal microstructure fabricated by semi-solid sintering.

    Science.gov (United States)

    Liu, L H; Yang, C; Kang, L M; Qu, S G; Li, X Q; Zhang, W W; Chen, W P; Li, Y Y; Li, P J; Zhang, L C

    2016-03-31

    It is well known that semi-solid forming could only obtain coarse-grained microstructure in a few alloy systems with a low melting point, such as aluminum and magnesium alloys. This work presents that semi-solid forming could also produce novel bimodal microstructure composed of nanostructured matrix and micro-sized (CoFe)Ti2 twins in a titanium alloy, Ti62Nb12.2Fe13.6Co6.4Al5.8. The semi-solid sintering induced by eutectic transformation to form a bimodal microstructure in Ti62Nb12.2Fe13.6Co6.4Al5.8 alloy is a fundamentally different approach from other known methods. The fabricated alloy exhibits high yield strength of 1790 MPa and plastic strain of 15.5%. The novel idea provides a new insight into obtaining nano-grain or bimodal microstructure in alloy systems with high melting point by semi-solid forming and into fabricating high-performance metallic alloys in structural applications.

  6. Polyimide and Metals MEMS Multi-User Processes

    KAUST Repository

    Arevalo, Arpys

    2016-11-01

    The development of a polyimide and metals multi-user surface micro-machining process for Micro-electro-mechanical Systems (MEMS) is presented. The process was designed to be as general as possible, and designed to be capable to fabricate different designs on a single silicon wafer. The process was not optimized with the purpose of fabricating any one specific device but can be tweaked to satisfy individual needs depending on the application. The fabrication process uses Polyimide as the structural material and three separated metallization layers that can be interconnected depending on the desired application. The technology allows the development of out-of-plane compliant mechanisms, which can be combined with six variations of different physical principles for actuation and sensing on a single processed silicon wafer. These variations are: electrostatic motion, thermal bimorph actuation, capacitive sensing, magnetic sensing, thermocouple-based sensing and radio frequency transmission and reception.

  7. Multiphase Model of Semisolid Slurry Generation and Isothermal Holding During Cooling Slope Rheoprocessing of A356 Al Alloy

    Science.gov (United States)

    Das, Prosenjit; Samanta, Sudip K.; Mondal, Biswanath; Dutta, Pradip

    2018-04-01

    In the present paper, we present an experimentally validated 3D multiphase and multiscale solidification model to understand the transport processes involved during slurry generation with a cooling slope. In this process, superheated liquid alloy is poured at the top of the cooling slope and allowed to flow along the slope under the influence of gravity. As the melt flows down the slope, it progressively loses its superheat, starts solidifying at the melt/slope interface with formation of solid crystals, and eventually exits the slope as semisolid slurry. In the present simulation, the three phases considered are the parent melt as the primary phase, and the solid grains and air as secondary phases. The air phase forms a definable air/liquid melt interface as the free surface. After exiting the slope, the slurry fills an isothermal holding bath maintained at the slope exit temperature, which promotes further globularization of microstructure. The outcomes of the present model include prediction of volume fractions of the three different phases considered, grain evolution, grain growth, size, sphericity and distribution of solid grains, temperature field, velocity field, macrosegregation and microsegregation. In addition, the model is found to be capable of making predictions of morphological evolution of primary grains at the onset of isothermal coarsening. The results obtained from the present simulations are validated by performing quantitative image analysis of micrographs of the rapidly oil-quenched semisolid slurry samples, collected from strategic locations along the slope and from the isothermal slurry holding bath.

  8. New applications and novel processing of refractory metal alloys

    International Nuclear Information System (INIS)

    Briant, C.L.

    2001-01-01

    Refractory metals have often been limited in their application because of their propensity to oxidize and to undergo a loos of yield strength at elevated temperatures. However, recent developments in both processing and alloy composition have opened the possibility that these materials might be used in structural applications that were not considered possible in the past. At the same time, the use of refractory metals in the electronics industry is growing, particularly with the use of tantalum as a diffusion barrier for copper metallization. Finally, the application of grain boundary engineering to the problem of intergranular fracture in these materials may allow processes to be developed that will produce alloys with a greater resistance to fracture. (author)

  9. Microfabrication process for patterning metallic lithium encapsulated electrodes

    International Nuclear Information System (INIS)

    Oukassi, Sami; Dunoyer, Nicolas; Salot, Raphael; Martin, Steve

    2009-01-01

    This work presents recent achievements concerning thin film encapsulation of metallic lithium negative electrode. In the context of this study, the encapsulation stack includes polymer and dielectric layers combined in such way to optimize barrier performances of the whole structure towards oxygen and water vapor permeation. The first part of this work is dedicated to the description of the barrier stack architecture and properties. A second part presents the application of a microfabrication process to the metallic lithium negative electrode and barrier stack so as to have very small features (100 μm x 100 μm patterns). The microfabrication process includes several steps of photolithography and etching (dry and wet) blocks, which allows us to reach the target critical dimensions. These results show a method of patterning functional metallic lithium. It demonstrates the feasibility of energy sources miniaturization which is an important issue in the field of autonomous and wireless sensor networks.

  10. A Method Based on Semi-Solid Forming for Eliminating Coarse Dendrites and Shrinkage Porosity of H13 Tool Steel

    Directory of Open Access Journals (Sweden)

    Yifeng Guo

    2018-04-01

    Full Text Available A method called forging solidifying metal (FSM, which is applied for eliminating coarse dendrites and shrinkage porosity defects of ferrous alloys was proposed based on semi-solid forming technology (SSF. To verify its feasibility, the effects of liquid fraction (FL on the microstructure of the deformed H13 steel were investigated experimentally. The coarse dendrites structure still existed and cracks appeared when the 0.1/s 50% FSM method was carried out at ~20% FL. What is significantly different from that is, the elimination of the coarse dendrites structure and shrinkage porosity defects became more significant, when this method was conducted at the end of solidification (FL < 10%. The microstructure of H13 steel was significantly refined and also became dense in such condition.

  11. Corrosion processes of physical vapor deposition-coated metallic implants.

    Science.gov (United States)

    Antunes, Renato Altobelli; de Oliveira, Mara Cristina Lopes

    2009-01-01

    Protecting metallic implants from the harsh environment of physiological fluids is essential to guaranteeing successful long-term use in a patient's body. Chemical degradation may lead to the failure of an implant device in two different ways. First, metal ions may cause inflammatory reactions in the tissues surrounding the implant and, in extreme cases, these reactions may inflict acute pain on the patient and lead to loosening of the device. Therefore, increasing wear strength is beneficial to the performance of the metallic implant. Second, localized corrosion processes contribute to the nucleation of fatigue cracks, and corrosion fatigue is the main reason for the mechanical failure of metallic implants. Common biomedical alloys such as stainless steel, cobalt-chrome alloys, and titanium alloys are prone to at least one of these problems. Vapor-deposited hard coatings act directly to improve corrosion, wear, and fatigue resistances of metallic materials. The effectiveness of the corrosion protection is strongly related to the structure of the physical vapor deposition layer. The aim of this paper is to present a comprehensive review of the correlation between the structure of physical vapor deposition layers and the corrosion properties of metallic implants.

  12. Application of laser assisted cold spraying process for metal deposition

    CSIR Research Space (South Africa)

    Tlotleng, Monnamme

    2014-02-01

    Full Text Available Laser assisted cold spraying (LACS) process is a hybrid technique that uses laser and cold spray to deposit solid powders on metal substrates. For bonding to occur, the particle velocities must be supersonic which are achieved by entraining...

  13. Process of forming a sol-gel/metal hydride composite

    Science.gov (United States)

    Congdon, James W [Aiken, SC

    2009-03-17

    An external gelation process is described which produces granules of metal hydride particles contained within a sol-gel matrix. The resulting granules are dimensionally stable and are useful for applications such as hydrogen separation and hydrogen purification. An additional coating technique for strengthening the granules is also provided.

  14. Trace Metal Levels in Raw and Heat Processed Nigerian Staple ...

    African Journals Online (AJOL)

    The levels of some trace metals (Fe, Zn, Cu, Ni, Cd) were quantitatively determined in raw and heat processed staple food cultivars (yam, cassava, cocoyam and maize) from oil producing areas of part of the Niger Delta and compared with a non-oil producing area of Ebonyi State as control. The survey was conducted to ...

  15. Coagulation / flocculation process in the removal of trace metals ...

    African Journals Online (AJOL)

    Attempts were made in this study to examine the effectiveness of polymer addition to coagulation process during treatment of a beverage industrial wastewater to remove some of its trace metals content such as lead, cadmium, total iron, total chromium, nickel and zinc. Experiments were conducted using the standard Jar ...

  16. Continuous process for selective metal extraction with an ionic liquid

    NARCIS (Netherlands)

    Parmentier, D.; Paradis, S.; Metz, S.J.; Wiedmer, S.K.; Kroon, M.C.

    2016-01-01

    This work describes for the first time a continuous process for selective metal extraction with an ionic liquid (IL) at room temperature. The hydrophobic fatty acid based IL tetraoctylphosphonium oleate ([P8888][oleate]) was specifically chosen for its low viscosity and high selectivity towards

  17. Gas discharge processes in the standard and metal channel PMTs

    International Nuclear Information System (INIS)

    Morozov, V.A.; Morozova, N.V.

    2015-01-01

    The effect of the potential difference at the focusing chamber electrodes of the XP2020, FEU-85, FEU-87, and FEU-93 photomultipliers on the intensity of afterpulses resulting from gas discharge processes is investigated. The time distribution of the afterpulses in the metal channel PMTs - H6780 and R7600U-200 - is studied as well

  18. Electrochemical activity of heavy metal oxides in the process of ...

    Indian Academy of Sciences (India)

    Unknown

    2002-02-02

    Feb 2, 2002 ... Electrochemical activity of heavy metal oxides in the process of chloride induced .... decrease of pH value by MeOx, a synergism of acidic and chloride ... inhibitors and their influence on the physical properties of. Portland ...

  19. Impact of heavy metals on the oil products biodegradation process.

    Science.gov (United States)

    Zukauskaite, Audrone; Jakubauskaite, Viktorija; Belous, Olga; Ambrazaitiene, Dalia; Stasiskiene, Zaneta

    2008-12-01

    Oil products continue to be used as a principal source of energy. Wide-scale production, transport, global use and disposal of petroleum have made them major contaminants in prevalence and quantity in the environment. In accidental spills, actions are taken to remove or remediate or recover the contaminants immediately, especially if they occur in environmentally sensitive areas, for example, in coastal zones. Traditional methods to cope with oil spills are confined to physical containment. Biological methods can have an advantage over the physical-chemical treatment regimes in removing spills in situ as they offer biodegradation of oil fractions by the micro-organisms. Recently, biological methods have been known to play a significant role in bioremediation of oil-polluted coastal areas. Such systems are likely to be of significance in the effective management of sensitive coastal ecosystems chronically subjected to oil spillage. For this reason the aim of this paper is to present an impact of Mn, Cu, Co and Mo quantities on oil biodegradation effectiveness in coastal soil and to determine the relationship between metal concentrations and degradation of two oil products (black oil and diesel fuel). Soil was collected in the Baltic Sea coastal zone oil products degradation area (Klaipeda, Lithuania). The experiment consisted of two parts: study on the influence of micro-elements on the oil product biodegradation process; and analysis of the influence of metal concentration on the number of HDMs. The analysis performed and results obtained address the following areas: impact of metal on a population of hydrocarbon degrading micro-organisms, impact of metals on residual concentrations of oil products, influence of metals on the growth of micro-organisms, inter-relation of metal concentrations with degradation rates. Statistical analysis was made using ;Statgraphics plus' software. The influence of metals on the growth of micro-organisms, the biodegradation process

  20. Process Modeling and Validation for Metal Big Area Additive Manufacturing

    Energy Technology Data Exchange (ETDEWEB)

    Simunovic, Srdjan [ORNL; Nycz, Andrzej [ORNL; Noakes, Mark W. [ORNL; Chin, Charlie [Dassault Systemes; Oancea, Victor [Dassault Systemes

    2017-05-01

    Metal Big Area Additive Manufacturing (mBAAM) is a new additive manufacturing (AM) technology based on the metal arc welding. A continuously fed metal wire is melted by an electric arc that forms between the wire and the substrate, and deposited in the form of a bead of molten metal along the predetermined path. Objects are manufactured one layer at a time starting from the base plate. The final properties of the manufactured object are dependent on its geometry and the metal deposition path, in addition to depending on the basic welding process parameters. Computational modeling can be used to accelerate the development of the mBAAM technology as well as a design and optimization tool for the actual manufacturing process. We have developed a finite element method simulation framework for mBAAM using the new features of software ABAQUS. The computational simulation of material deposition with heat transfer is performed first, followed by the structural analysis based on the temperature history for predicting the final deformation and stress state. In this formulation, we assume that two physics phenomena are coupled in only one direction, i.e. the temperatures are driving the deformation and internal stresses, but their feedback on the temperatures is negligible. The experiment instrumentation (measurement types, sensor types, sensor locations, sensor placements, measurement intervals) and the measurements are presented. The temperatures and distortions from the simulations show good correlation with experimental measurements. Ongoing modeling work is also briefly discussed.

  1. The obtained of concentrates containing precious metals for pyrometallurgical processing

    Directory of Open Access Journals (Sweden)

    B. Oleksiak

    2014-10-01

    Full Text Available In the presented study the flotation process has been proposed as a method of enrichment of silver-bearing jewellery waste. This method, traditionally used for the enrichment of non-ferrous metal ores, is based on differences in wettability between individual minerals. Flotation concentrate, enriched with Ag, was subjected to further processing by the pyrometallurgical method in order to produce silver from these wastes.

  2. The obtained of concentrates containing precious metals for pyrometallurgical processing

    OpenAIRE

    Oleksiak, B.; Siwiec, G.; Blacha-Grzechnik, A.; Wieczorek, J.

    2014-01-01

    In the presented study the flotation process has been proposed as a method of enrichment of silver-bearing jewellery waste. This method, traditionally used for the enrichment of non-ferrous metal ores, is based on differences in wettability between individual minerals. Flotation concentrate, enriched with Ag, was subjected to further processing by the pyrometallurgical method in order to produce silver from these wastes.

  3. Synthesis and processing of composites by reactive metal penetration

    Energy Technology Data Exchange (ETDEWEB)

    Loehman, R.E.; Ewsuk, K.G. [Sandia National Labs., Albuquerque, NM (United States); Tomsia, A.P. [Pask Research and Engineering, Berkeley, CA (United States)] [and others

    1997-04-01

    Achieving better performance in commercial products and processes often is dependent on availability of new and improved materials. Ceramic-metal composites have advantages over more conventional materials because of their high stiffness-to-weight ratios, good fracture toughness, and because their electrical and thermal properties can be varied through control of their compositions and microstructures. However, ceramic composites will be more widely used only when their costs are competitive with other materials and when designers have more confidence in their reliability. Over the past four years reactive metal penetration has been shown to be a promising technique for making ceramic and metal-matrix composites to near-net-shape with control of both composition and microstructure. It appears that, with sufficient development, reactive metal penetration could be an economical process for manufacturing many of the advanced ceramic composites that are needed for light-weight structural and wear applications for transportation and energy conversion devices. Near-net-shape fabrication of parts is a significant advantage because costly and energy intensive grinding and machining operations are substantially reduced, and the waste generated from such finishing operations is minimized. The most promising compositions to date consist of Al and Al{sub 2}O{sub 3}; thus, these composites should be of particular interest to the aluminum industry. The goals of this ceramic-metal composite research and development program are: (1) to identify compositions favorable for making composites by reactive metal penetration; (2) to understand the mechanism(s) by which these composites are formed; (3) to control and optimize the process so that composites and composite coatings can be made economically; and (4) to apply R&D results to problems of interest to the aluminum industry.

  4. Semi-solid state fermentation of bagasse for hydrogen production; the cost-effective approach in Indian context

    International Nuclear Information System (INIS)

    Singh, S.P.; Asthana, R.K.; Singh, A.P.

    2006-01-01

    Semi-solid state fermentation route of hydrogen production from agro-waste sugar cane bagasse was tried using the photosynthetic bacterium Rhodopseudomonas (BHU strain-1) and the non-photosynthetic Enterobacter aerogenes MTCC2822. The process seems an alternative to submerged fermentation that requires high volumes of nutrient broth. Bagasse (10 g) pre-hydrolyzed with NaOH (2%, w/v) was coated with Ca-alginate (1.5%, v/v) containing Rhodopseudomonas and E. aerogenes in the co-immobilized state (300 μg bacterial biomass ml -1 ). The fermenting medium was just 150 ml to sustain the moistened bagasse in a 0.5 L fermenter kept in light. A parallel set of free bacterial cells served as control. Hydrogen production by the immobilized sets reached 30 L within 60 h with the average rate of 0.177 L H 2 h -1 . For free cells, the values for hydrogen output (20 L) or the rate 0.1125 L H 2 h -1 were approximately 1.5-fold low. It is proposed that semi-solid fermentation route of hydrogen production from bagasse will be a cost-effective technology in countries generating this agro-waste. (authors)

  5. Semi-solid state fermentation of bagasse for hydrogen production; the cost-effective approach in Indian context

    Energy Technology Data Exchange (ETDEWEB)

    Singh, S.P.; Asthana, R.K.; Singh, A.P. [Centre of Advanced Study in Botany, Banaras Hindu University, Varanasi-221005, (India)

    2006-07-01

    Semi-solid state fermentation route of hydrogen production from agro-waste sugar cane bagasse was tried using the photosynthetic bacterium Rhodopseudomonas (BHU strain-1) and the non-photosynthetic Enterobacter aerogenes MTCC2822. The process seems an alternative to submerged fermentation that requires high volumes of nutrient broth. Bagasse (10 g) pre-hydrolyzed with NaOH (2%, w/v) was coated with Ca-alginate (1.5%, v/v) containing Rhodopseudomonas and E. aerogenes in the co-immobilized state (300 {mu}g bacterial biomass ml{sup -1}). The fermenting medium was just 150 ml to sustain the moistened bagasse in a 0.5 L fermenter kept in light. A parallel set of free bacterial cells served as control. Hydrogen production by the immobilized sets reached 30 L within 60 h with the average rate of 0.177 L H{sub 2} h{sup -1}. For free cells, the values for hydrogen output (20 L) or the rate 0.1125 L H{sub 2} h{sup -1} were approximately 1.5-fold low. It is proposed that semi-solid fermentation route of hydrogen production from bagasse will be a cost-effective technology in countries generating this agro-waste. (authors)

  6. Infiltration processing of metal matrix composites using coated ceramic particulates

    Science.gov (United States)

    Leon-Patino, Carlos Alberto

    2001-07-01

    A new process was developed to fabricate particulate metal matrix composites (MMCs). The process involves three steps: (1) modifying the particulate surface by metal coating, (2) forming a particulate porous compact; and (3) introducing metal into the channel network by vacuum infiltration. MMCs with different reinforcements, volume fractions, and sizes can be produced by this technique. Powders of alumina and silicon carbide were successfully coated with nickel and copper in preparation for infiltration with molten aluminum. Electroless Ni and Cu deposition was used since it enhances the wettability of the reinforcements for composite fabrication. While Cu deposits were polycrystalline, traces of phosphorous co-deposited from the electroless bath gave an amorphous Ni-P coating. The effect of metal coating on wetting behavior was evaluated at 800°C on plain and metal-coated ceramic plates using a sessile drop technique. The metallic films eliminated the non-wetting behavior of the uncoated ceramics, leading to equilibrium contact angles in the order of 12° and below 58° for Ni and Cu coated ceramics, respectively. The spreading data indicated that local diffusion at the triple junction was the governing mechanism of the wetting process. Precipitation of intermetallic phases in the drop/ceramic interface delayed the formation of Al4C3. Infiltration with molten Al showed that the coated-particulates are suitable as reinforcing materials for fabricating MMCs, giving porosity-free components with a homogeneously distributed reinforcing phase. The coating promoted easy metal flow through the preform, compared to the non-infiltration behavior of the uncoated counterparts. Liquid state diffusion kinetics due to temperature dependent viscosity forces controlled the infiltration process. Microstructural analysis indicated the formation of intermetallic phases such as CuAl 2, in the case of Cu coating, and Ni2Al3 and NiAl 3 when Ni-coated powders were infiltrated. The

  7. Nuclear processes in deuterium/natural hydrogen-metal systems

    International Nuclear Information System (INIS)

    Zelensky, V.F.

    2013-01-01

    The survey presents the analysis of the phenomena taking place in deuterium - metal and natural hydrogen - metal systems under cold fusion experimental conditions. The cold fusion experiments have shown that the generation of heat and helium in the deuterium-metal system without emission of energetic gamma-quanta is the result of occurrence of a chain of chemical, physical and nuclear processes observed in the system, culminating in both the fusion of deuterium nuclei and the formation of a virtual, electron-modified excited 4He nucleus. The excitation energy of the helium nucleus is transferred to the matrix through emission of conversion electrons, and that, under appropriate conditions, provides a persistent synthesis of deuterium. The processes occurring in the deuterium/natural hydrogen - metal systems have come to be known as chemonuclear DD- and HD-fusion. The mechanism of stimulation of weak interaction reactions under chemonuclear deuterium fusion conditions by means of strong interaction reactions has been proposed. The results of numerous experiments discussed in the survey bear witness to the validity of chemonuclear fusion. From the facts discussed it is concluded that the chemonuclear deuterium fusion scenario as presented in this paper may serve as a basis for expansion of deeper research and development of this ecologically clean energy source. It is shown that the natural hydrogen-based system, containing 0.015% of deuterium, also has good prospects as an energy source. The chemonuclear fusion processes do not require going beyond the scope of traditional physics for their explanation

  8. Bilayer lift-off process for aluminum metallization

    Science.gov (United States)

    Wilson, Thomas E.; Korolev, Konstantin A.; Crow, Nathaniel A.

    2015-01-01

    Recently published reports in the literature for bilayer lift-off processes have described recipes for the patterning of metals that have recommended metal-ion-free developers, which do etch aluminum. We report the first measurement of the dissolution rate of a commercial lift-off resist (LOR) in a sodium-based buffered commercial developer that does not etch aluminum. We describe a reliable lift-off recipe that is safe for multiple process steps in patterning thin (recipe consists of an acid cleaning of the substrate, the bilayer (positive photoresist/LOR) deposition and development, the sputtering of the aluminum film along with a palladium capping layer and finally, the lift-off of the metal film by immersion in the LOR solvent. The insertion into the recipe of postexposure and sequential develop-bake-develop process steps are necessary for an acceptable undercut. Our recipe also eliminates any need for accompanying sonication during lift-off that could lead to delamination of the metal pattern from the substrate. Fine patterns were achieved for both 100-nm-thick granular aluminum/palladium bilayer bolometers and 500-nm-thick aluminum gratings with 6-μm lines and 4-μm spaces.

  9. Spectral BRDF measurements of metallic samples for laser processing applications

    International Nuclear Information System (INIS)

    Vitali, L; Fustinoni, D; Gramazio, P; Niro, A

    2015-01-01

    The spectral bidirectional reflectance distribution function (BRDF) of metals plays an important role in industrial processing involving laser-surface interaction. In particular, in laser metal machining, absorbance is strongly dependent on the radiation incidence angle as well as on finishing and contamination grade of the surface, and in turn it can considerably affect processing results. Very recently, laser radiation is also used to structure metallic surfaces, in order to produce many particular optical effects, ranging from a high level polishing to angular color shifting. Of course, full knowledge of the spectral BRDF of these structured layers makes it possible to infer reflectance or color for any irradiation and viewing angles. In this paper, we present Vis-NIR spectral BRDF measurements of laser-polished metallic, opaque, flat samples commonly employed in such applications. The resulting optical properties seem to be dependent on the atmospheric composition during the polishing process in addition to the roughness. The measurements are carried out with a Perkin Elmer Lambda 950 double-beam spectrophotometer, equipped with the Absolute Reflectance/Transmittance Analyzer (ARTA) motorized goniometer. (paper)

  10. Esophageal transit scintigraphy in healthy volunteers using TC-99M sulphur colloid semisolid jelly

    International Nuclear Information System (INIS)

    Ashwani Sood; Kumar, U.; Gambhir, S.; Sewatkar, A.B.; Kheruka, S.C.; Dube, V.

    2004-01-01

    Functional symptoms caused by esophageal motor disorders are very common. The esophageal transit scintigraphy has been done using liquid and solid meals to understand pathophysiology of esophageal motor disorders better. The present study was aimed to develop and standardize a stable and easily acceptable radioactive semisolid meal for esophageal transit scintigraphy. Semisolid jelly incorporated with Tc-99m sulphur colloid was prepared from the commercially available edible jelly powder-containing gelatin. The tracer stability was investigated by in-vitro method up to 4 hours to test the affinity of tracer and mechanical stability of semisolid meal. The amount of semisolid meal per bolus was also standardized in relation to ease of swallowing and free passage of it through whole of esophagus. The additional objective was to establish the normal esophageal transit scintigraphic parameters. Materials and methods: A total of 31 normal volunteers were studied. The esophageal transit scintigraphy was performed in supine and sitting positions thrice using single bolus of 2 gm semisolid jelly containing 7.4 MBq (200uCi) of tracer for the acquisition period of 192 seconds. The esophageal emptying time for 50% (T50) and for 90% (T90) were calculated by computer analysis in addition to generation of condensed dynamic images. Results: The 50% and 90% whole esophageal emptying time are given below in the table in sitting and supine positions respectively.(P<0.05). Conclusions: Condensed dynamic images revealed normal transit pattern without delay or stasis and fragmentation of bolus through the esophagus. The stability and homogeneity of tracer in the semisolid meal provided a simple and reliable method for carrying out esophageal transit scintigraphy. It was found that this bolus was well accepted by normal volunteers and values obtained were well within the acceptable range. Thus we established the normal values in our laboratory and also standardized a semisolid meal with

  11. Review of friction modeling in metal forming processes

    DEFF Research Database (Denmark)

    Nielsen, C.V.; Bay, N.

    2018-01-01

    Abstract In metal forming processes, friction between tool and workpiece is an important parameter influencing the material flow, surface quality and tool life. Theoretical models of friction in metal forming are based on analysis of the real contact area in tool-workpiece interfaces. Several...... research groups have studied and modeled the asperity flattening of workpiece material against tool surface in dry contact or in contact interfaces with only thin layers of lubrication with the aim to improve understanding of friction in metal forming. This paper aims at giving a review of the most...... conditions, normal pressure, sliding length and speed, temperature changes, friction on the flattened plateaus and deformation of the underlying material. The review illustrates the development in the understanding of asperity flattening and the methods of analysis....

  12. Research on plant of metal fuel fabrication using casting process

    International Nuclear Information System (INIS)

    Senda, Yasuhide; Mori, Yukihide

    2003-12-01

    This document presents the plant concept of metal fuel fabrication system (38tHM/y) using casting process in electrolytic recycle, which based on recent studies of its equipment design and quality control system. And we estimate the cost of its construction and operation, including costs of maintenance, consumed hardware and management of waste. The content of this work is as follows. (1) Designing of fuel fabrication equipment: We make material flow diagrams of the fuel fabrication plant and rough designs of the injection casting furnace, demolder and inspection equipment. (2) Designing of resolution system of liquid waste, which comes from analytical process facility. Increased analytical items, we rearrange analytical process facility, estimate its chemicals and amount of waste. (3) Arrangement of equipments: We made a arrangement diagram of the metal fuel fabrication equipments in cells. (4) Estimation of cost data: We estimated cost to construct the facility and to operate it. (author)

  13. Advanced Wear Simulation for Bulk Metal Forming Processes

    Directory of Open Access Journals (Sweden)

    Behrens Bernd-Arno

    2016-01-01

    Full Text Available In the recent decades the finite element method has become an essential tool for the cost-efficient virtual process design in the metal forming sector in order to counter the constantly increasing quality standards, particularly from the automotive industry as well as intensified international competition in the forging industry. An optimized process design taking precise tool wear prediction into account is a way to increase the cost-efficiency of the bulk metal forming processes. The main objective of the work presented in this paper is a modelling algorithm, which allows predicting die wear with respect to a geometry update during the forming simulation. Changes in the contact area caused by geometry update lead to the different die wear distribution. It primarily concerns the die areas, which undergo high thermal and mechanical loads.

  14. Porosity Measurements and Analysis for Metal Additive Manufacturing Process Control.

    Science.gov (United States)

    Slotwinski, John A; Garboczi, Edward J; Hebenstreit, Keith M

    2014-01-01

    Additive manufacturing techniques can produce complex, high-value metal parts, with potential applications as critical metal components such as those found in aerospace engines and as customized biomedical implants. Material porosity in these parts is undesirable for aerospace parts - since porosity could lead to premature failure - and desirable for some biomedical implants - since surface-breaking pores allows for better integration with biological tissue. Changes in a part's porosity during an additive manufacturing build may also be an indication of an undesired change in the build process. Here, we present efforts to develop an ultrasonic sensor for monitoring changes in the porosity in metal parts during fabrication on a metal powder bed fusion system. The development of well-characterized reference samples, measurements of the porosity of these samples with multiple techniques, and correlation of ultrasonic measurements with the degree of porosity are presented. A proposed sensor design, measurement strategy, and future experimental plans on a metal powder bed fusion system are also presented.

  15. Relaxation processes and physical aging in metallic glasses

    Science.gov (United States)

    Ruta, B.; Pineda, E.; Evenson, Z.

    2017-12-01

    Since their discovery in the 1960s, metallic glasses have continuously attracted much interest across the physics and materials science communities. In the forefront are their unique properties, which hold the alluring promise of broad application in fields as diverse as medicine, environmental science and engineering. However, a major obstacle to their wide-spread commercial use is their inherent temporal instability arising from underlying relaxation processes that can dramatically alter their physical properties. The result is a physical aging process which can bring about degradation of mechanical properties, namely through embrittlement and catastrophic mechanical failure. Understanding and controlling the effects of aging will play a decisive role in our on-going endeavor to advance the use of metallic glasses as structural materials, as well as in the more general comprehension of out-of-equilibrium dynamics in complex systems. This review presents an overview of the current state of the art in the experimental advances probing physical aging and relaxation processes in metallic glasses. Similarities and differences between other hard and soft matter glasses are highlighted. The topic is discussed in a multiscale approach, first presenting the key features obtained in macroscopic studies, then connecting them to recent novel microscopic investigations. Particular emphasis is put on the occurrence of distinct relaxation processes beyond the main structural process in viscous metallic melts and their fate upon entering the glassy state, trying to disentangle results and formalisms employed by the different groups of the glass-science community. A microscopic viewpoint is presented, in which physical aging manifests itself in irreversible atomic-scale processes such as avalanches and intermittent dynamics, ascribed to the existence of a plethora of metastable glassy states across a complex energy landscape. Future experimental challenges and the comparison with

  16. The Chemophytostabilisation Process of Heavy Metal Polluted Soil.

    Science.gov (United States)

    Grobelak, Anna; Napora, Anna

    2015-01-01

    Industrial areas are characterised by soil degradation processes that are related primarily to the deposition of heavy metals. Areas contaminated with metals are a serious source of risk due to secondary pollutant emissions and metal leaching and migration in the soil profile and into the groundwater. Consequently, the optimal solution for these areas is to apply methods of remediation that create conditions for the restoration of plant cover and ensure the protection of groundwater against pollution. Remediation activities that are applied to large-scale areas contaminated with heavy metals should mainly focus on decreasing the degree of metal mobility in the soil profile and metal bioavailability to levels that are not phytotoxic. Chemophytostabilisation is a process in which soil amendments and plants are used to immobilise metals. The main objective of this research was to investigate the effects of different doses of organic amendments (after aerobic sewage sludge digestion in the food industry) and inorganic amendments (lime, superphosphate, and potassium phosphate) on changes in the metals fractions in soils contaminated with Cd, Pb and Zn during phytostabilisation. In this study, the contaminated soil was amended with sewage sludge and inorganic amendments and seeded with grass (tall fescue) to increase the degree of immobilisation of the studied metals. The contaminated soil was collected from the area surrounding a zinc smelter in the Silesia region of Poland (pH 5.5, Cd 12 mg kg-1, Pb 1100 mg kg-1, Zn 700 mg kg-1). A plant growth experiment was conducted in a growth chamber for 5 months. Before and after plant growth, soil subsamples were subjected to chemical and physical analyses. To determine the fractions of the elements, a sequential extraction method was used according to Zeien and Brümmer. Research confirmed that the most important impacts on the Zn, Cd and Pb fractions included the combined application of sewage sludge from the food industry and

  17. The Chemophytostabilisation Process of Heavy Metal Polluted Soil.

    Directory of Open Access Journals (Sweden)

    Anna Grobelak

    Full Text Available Industrial areas are characterised by soil degradation processes that are related primarily to the deposition of heavy metals. Areas contaminated with metals are a serious source of risk due to secondary pollutant emissions and metal leaching and migration in the soil profile and into the groundwater. Consequently, the optimal solution for these areas is to apply methods of remediation that create conditions for the restoration of plant cover and ensure the protection of groundwater against pollution. Remediation activities that are applied to large-scale areas contaminated with heavy metals should mainly focus on decreasing the degree of metal mobility in the soil profile and metal bioavailability to levels that are not phytotoxic. Chemophytostabilisation is a process in which soil amendments and plants are used to immobilise metals. The main objective of this research was to investigate the effects of different doses of organic amendments (after aerobic sewage sludge digestion in the food industry and inorganic amendments (lime, superphosphate, and potassium phosphate on changes in the metals fractions in soils contaminated with Cd, Pb and Zn during phytostabilisation. In this study, the contaminated soil was amended with sewage sludge and inorganic amendments and seeded with grass (tall fescue to increase the degree of immobilisation of the studied metals. The contaminated soil was collected from the area surrounding a zinc smelter in the Silesia region of Poland (pH 5.5, Cd 12 mg kg-1, Pb 1100 mg kg-1, Zn 700 mg kg-1. A plant growth experiment was conducted in a growth chamber for 5 months. Before and after plant growth, soil subsamples were subjected to chemical and physical analyses. To determine the fractions of the elements, a sequential extraction method was used according to Zeien and Brümmer. Research confirmed that the most important impacts on the Zn, Cd and Pb fractions included the combined application of sewage sludge from the

  18. Quantification of active ingredients in semi-solid pharmaceutical formulations by near infrared spectroscopy.

    Science.gov (United States)

    Schlegel, Lisa B; Schubert-Zsilavecz, Manfred; Abdel-Tawab, Mona

    2017-08-05

    Near infrared (NIR) spectroscopy is increasingly gaining significance in the pharmaceutical industry for quality and in-process control. However, the potential of this method for quantitative quality control in pharmacies has long been neglected and little data is available on its application in analysis of creams and ointments. This study evaluated the applicability of NIR spectrometer with limited wavelength range (1000-1900nm) for quantitative quality control of six different dermatological semi-solid pharmaceutical preparations. Each contained a frequently used active ingredient in a common concentration either in a water-free lipid base or in an aqueous cream matrix. Based on direct NIR transflectance measurements through standardized glass beakers and partial least squares (PLS) multivariate calibration, quantitative models were generated comparing several data pre-processing methods Whereas difficulties were observed for mixtures containing 2% (w/w) metronidazole or 4% (w/w) erythromycin, content determination was possible with sufficient accuracy for salicylic acid (5 % (w/w)) and urea (10% (w/w)) in hydrophilic as well as in lipophilic formulations meeting the limit of a maximum deviation of±5% (relative) from the reference values. Exemplarily, one of the methods was successfully validated according to the EMA Guideline, determining several figures of merit such as specificity, linearity, accuracy, precision and robustness. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Process, structure, property and applications of metallic glasses

    Directory of Open Access Journals (Sweden)

    B. Geetha Priyadarshini

    2016-07-01

    Full Text Available Metallic glasses (MGs are gaining immense technological significance due to their unique structure-property relationship with renewed interest in diverse field of applications including biomedical implants, commercial products, machinery parts, and micro-electro-mechanical systems (MEMS. Various processing routes have been adopted to fabricate MGs with short-range ordering which is believed to be the genesis of unique structure. Understanding the structure of these unique materials is a long-standing unsolved mystery. Unlike crystalline counterpart, the outstanding properties of metallic glasses owing to the absence of grain boundaries is reported to exhibit high hardness, excellent strength, high elastic strain, and anti-corrosion properties. The combination of these remarkable properties would significantly contribute to improvement of performance and reliability of these materials when incorporated as bio-implants. The nucleation and growth of metallic glasses is driven by thermodynamics and kinetics in non-equilibrium conditions. This comprehensive review article discusses the various attributes of metallic glasses with an aim to understand the fundamentals of relationship process-structure-property existing in such unique class of material.

  20. Different strategies for recovering metals from CARON process residue

    International Nuclear Information System (INIS)

    Cabrera, G.; Gomez, J.M.; Hernandez, I.; Coto, O.; Cantero, D.

    2011-01-01

    The capacity of Acidithiobacillus thiooxidans DMS 11478 to recover the heavy metals contained in the residue obtained from the CARON process has been evaluated. Different bioreactor configurations were studied: a two-stage batch system and two semi-continuous systems (stirred-tank reactor leaching and column leaching). In the two-stage system, 46.8% Co, 36.0% Mg, 26.3% Mn and 22.3% Ni were solubilised after 6 h of contact between the residue and the bacteria-free bioacid. The results obtained with the stirred-tank reactor and the column were similar: 50% of the Mg and Co and 40% of the Mn and Ni were solubilised after thirty one days. The operation in the column reactor allowed the solid-liquid ratio to be increased and the pH to be kept at low values (<1.0). Recirculation of the leachate in the column had a positive effect on metal removal; at sixty five days (optimum time) the solubilisation levels were as follows: 86% Co, 83% Mg, 72% Mn and Ni, 62% Fe and 23% Cr. The results corroborate the feasibility of the systems studied for the leaching of metals from CARON process residue and these methodologies can be considered viable for the recovery of valuable metals.

  1. Semi solid metal processing: The fraction solid dilemma

    International Nuclear Information System (INIS)

    Nafisi, S.; Emadi, D.; Ghomashchi, R.

    2009-01-01

    One of the most challenging aspects in semi solid metal (SSM) processing is to determine the actual volume fraction of the solid at the processing temperature. The fraction has great impact on the SSM slurry viscosity and the subsequent filling of the mold in the casting stage. Three methods, namely quantitative metallography, thermodynamic calculation, and thermal analysis are employed to investigate and clarify the contradictory open literature reports about the real value of the volume fraction of primary particles. It is reported that the discrepancies between the results obtained by different methods are caused mainly by variations in cooling rates and by coarsening of the primaries during the quenching process

  2. Semi solid metal processing: The fraction solid dilemma

    Energy Technology Data Exchange (ETDEWEB)

    Nafisi, S. [EVRAZ Inc. NA 100 Armour Road, Regina, SK, S4P 3C7 (Canada)], E-mail: Shahrooz.Nafisi@evrazincna.com; Emadi, D. [CEPG, CanmetENERGY, Natural Resources Canada, Ottawa, ON, K1A 1M1 (Canada); Ghomashchi, R. [Advanced Materials and Processing Research Institute, Suite 122, A7-1390 Major MacKenzie, ON, L4S 0A1 (Canada)

    2009-05-15

    One of the most challenging aspects in semi solid metal (SSM) processing is to determine the actual volume fraction of the solid at the processing temperature. The fraction has great impact on the SSM slurry viscosity and the subsequent filling of the mold in the casting stage. Three methods, namely quantitative metallography, thermodynamic calculation, and thermal analysis are employed to investigate and clarify the contradictory open literature reports about the real value of the volume fraction of primary particles. It is reported that the discrepancies between the results obtained by different methods are caused mainly by variations in cooling rates and by coarsening of the primaries during the quenching process.

  3. SOLVENT EXTRACTION PROCESS FOR SEPARATING ACTINIDE AND LANTHANIDE METAL VALUES

    Science.gov (United States)

    Hildebrandt, R.A.; Hyman, H.H.; Vogler, S.

    1962-08-14

    A process of countercurrently extracting an aqueous mineral acid feed solution for the separation of actinides from lanthanides dissolved therern is described. The feed solution is made acid-defrcient with alkali metal hydroxide prior to.contact with acid extractant; during extraction, however, acid is transferred from organic to aqueous solution and the aqueous solution gradually becomes acid. The acid-deficient phase ' of the process promotes the extraction of the actinides, while the latter acid phase'' of the process improves retention of the lanthanides in the aqueous solution. This provides for an improved separation. (AEC)

  4. A metallic buried interconnect process for through-wafer interconnection

    International Nuclear Information System (INIS)

    Ji, Chang-Hyeon; Herrault, Florian; Allen, Mark G

    2008-01-01

    In this paper, we present the design, fabrication process and experimental results of electroplated metal interconnects buried at the bottom of deep silicon trenches with vertical sidewalls. A manual spray-coating process along with a unique trench-formation process has been developed for the electroplating of a metal interconnection structure at the bottom surface of the deep trenches. The silicon etch process combines the isotropic dry etch process and conventional Bosch process to fabricate a deep trench with angled top-side edges and vertical sidewalls. The resulting trench structure, in contrast to the trenches fabricated by wet anisotropic etching, enables spray-coated photoresist patterning with good sidewall and top-side edge coverage while maintaining the ability to form a high-density array of deep trenches without excessive widening of the trench opening. A photoresist spray-coating process was developed and optimized for the formation of electroplating mold at the bottom of 300 µm deep trenches having vertical sidewalls. A diluted positive tone photoresist with relatively high solid content and multiple coating with baking between coating steps has been experimentally proven to provide high quality sidewall and edge coverage. To validate the buried interconnect approach, a three-dimensional daisy chain structure having a buried interconnect as the bottom connector and traces on the wafer surface as the top conductor has been designed and fabricated

  5. Manufacturing process for the metal ceramic hybrid fuel cladding tube

    International Nuclear Information System (INIS)

    Jung, Yang Il; Kim, Sun Han; Park, Jeong Yong

    2012-01-01

    For application in LWRs with suppressed hydrogen release, a metal-ceramic hybrid cladding tube has been proposed. The cladding consists of an inner zirconium tube and outer SiC fiber matrix SiC ceramic composite. The inner zirconium allows the matrix to remain fully sealed even if the ceramic matrix cracks through. The outer SiC composite can increase the safety margin by taking the merits of the SiC itself. However, it is a challenging task to fabricate the metal-ceramic hybrid tube. Processes such as filament winding, matrix impregnation, and surface costing are additionally required for the existing Zr based fuel cladding tubes. In the current paper, the development of the manufacturing process will be introduced

  6. Biological removal of metal ions from aqueous process streams

    International Nuclear Information System (INIS)

    Shumate, S.E. II; Strandberg, G.W.; Parrott, J.R. Jr.

    1978-01-01

    Aqueous waste streams from nuclear fuel processing operations may contain trace quantities of heavy metals such as uranium. Conventional chemical and physical treatment may be ineffective or very expensive when uranium concentrations in the range of 10 to 100 g/m 3 must be reduced to 1 g/m 3 or less. The ability of some microorganisms to adsorb or complex dissolved heavy metals offers an alternative treatment method. Uranium uptake by Saccharomyces cerevisiae NRRL Y-2574 and a strain of Pseudomonas aeruginosa was examined to identify factors which might affect a process for the removal of uranium from wastewater streams. At uranium concentrations in the range of 10 to 500 g/m 3 , where the binding capacity of the biomass was not exceeded, temperature, pH, and initial uranium concentration were found to influence the rate of uranium uptake, but not the soluble uranium concentration at equilibrium. 6 figs

  7. Manufacturing process for the metal ceramic hybrid fuel cladding tube

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Yang Il; Kim, Sun Han; Park, Jeong Yong [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2012-10-15

    For application in LWRs with suppressed hydrogen release, a metal-ceramic hybrid cladding tube has been proposed. The cladding consists of an inner zirconium tube and outer SiC fiber matrix SiC ceramic composite. The inner zirconium allows the matrix to remain fully sealed even if the ceramic matrix cracks through. The outer SiC composite can increase the safety margin by taking the merits of the SiC itself. However, it is a challenging task to fabricate the metal-ceramic hybrid tube. Processes such as filament winding, matrix impregnation, and surface costing are additionally required for the existing Zr based fuel cladding tubes. In the current paper, the development of the manufacturing process will be introduced.

  8. Effect of semisolid formulation of persea americana mill (avocado) oil on wound healing in rats.

    Science.gov (United States)

    de Oliveira, Ana Paula; Franco, Eryvelton de Souza; Rodrigues Barreto, Rafaella; Cordeiro, Daniele Pires; de Melo, Rebeca Gonçalves; de Aquino, Camila Maria Ferreira; E Silva, Antonio Alfredo Rodrigues; de Medeiros, Paloma Lys; da Silva, Teresinha Gonçalves; Góes, Alexandre José da Silva; Maia, Maria Bernadete de Sousa

    2013-01-01

    The aim of this study was to evaluate the wound-healing activity of a semisolid formulation of avocado oil, SSFAO 50%, or avocado oil in natura, on incisional and excisional cutaneous wound models in Wistar rats. An additional objective was to quantify the fatty acids present in avocado oil. On the 14th day, a significant increase was observed in percentage wound contraction and reepithelialization in the groups treated with 50% SSFAO or avocado oil compared to the petroleum jelly control. Anti-inflammatory activity, increase in density of collagen, and tensile strength were observed inSSFAO 50% or avocado oil groups, when compared to control groups. The analysis of the components of avocado oil by gas chromatography detected the majority presence of oleic fatty acid (47.20%), followed by palmitic (23.66%), linoleic (13.46%) docosadienoic (8.88%), palmitoleic (3.58%), linolenic (1.60%), eicosenoic (1.29%), and myristic acids (0.33%). Our results show that avocado oil is a rich source of oleic acid and contains essential fatty acids. When used in natura or in pharmaceutical formulations for topical use, avocado oil can promote increased collagen synthesis and decreased numbers of inflammatory cells during the wound-healing process and may thus be considered a new option for treating skin wounds.

  9. [INVITED] Evaluation of process observation features for laser metal welding

    Science.gov (United States)

    Tenner, Felix; Klämpfl, Florian; Nagulin, Konstantin Yu.; Schmidt, Michael

    2016-06-01

    In the present study we show how fast the fluid dynamics change when changing the laser power for different feed rates during laser metal welding. By the use of two high-speed cameras and a data acquisition system we conclude how fast we have to image the process to measure the fluid dynamics with a very high certainty. Our experiments show that not all process features which can be measured during laser welding do represent the process behavior similarly well. Despite the good visibility of the vapor plume the monitoring of its movement is less suitable as an input signal for a closed-loop control. The features measured inside the keyhole show a good correlation with changes of process parameters. Due to its low noise, the area of the keyhole opening is well suited as an input signal for a closed-loop control of the process.

  10. Architectural design of heterogeneous metallic nanocrystals--principles and processes.

    Science.gov (United States)

    Yu, Yue; Zhang, Qingbo; Yao, Qiaofeng; Xie, Jianping; Lee, Jim Yang

    2014-12-16

    CONSPECTUS: Heterogeneous metal nanocrystals (HMNCs) are a natural extension of simple metal nanocrystals (NCs), but as a research topic, they have been much less explored until recently. HMNCs are formed by integrating metal NCs of different compositions into a common entity, similar to the way atoms are bonded to form molecules. HMNCs can be built to exhibit an unprecedented architectural diversity and complexity by programming the arrangement of the NC building blocks ("unit NCs"). The architectural engineering of HMNCs involves the design and fabrication of the architecture-determining elements (ADEs), i.e., unit NCs with precise control of shape and size, and their relative positions in the design. Similar to molecular engineering, where structural diversity is used to create more property variations for application explorations, the architectural engineering of HMNCs can similarly increase the utility of metal NCs by offering a suite of properties to support multifunctionality in applications. The architectural engineering of HMNCs calls for processes and operations that can execute the design. Some enabling technologies already exist in the form of classical micro- and macroscale fabrication techniques, such as masking and etching. These processes, when used singly or in combination, are fully capable of fabricating nanoscopic objects. What is needed is a detailed understanding of the engineering control of ADEs and the translation of these principles into actual processes. For simplicity of execution, these processes should be integrated into a common reaction system and yet retain independence of control. The key to architectural diversity is therefore the independent controllability of each ADE in the design blueprint. The right chemical tools must be applied under the right circumstances in order to achieve the desired outcome. In this Account, after a short illustration of the infinite possibility of combining different ADEs to create HMNC design

  11. Solidification in direct metal deposition by LENS processing

    Science.gov (United States)

    Hofmeister, William; Griffith, Michelle

    2001-09-01

    Thermal imaging and metallographic analysis were used to study Laser Engineered Net Shaping (LENS™) processing of 316 stainless steel and H13 tool steel. The cooling rates at the solid-liquid interface were measured over a range of conduction conditions. The length scale of the molten zone controls cooling rates during solidification in direct metal deposition. In LENS processing, the molten zone ranges from 0.5 mm in length to 1.5 mm, resulting in cooling rates at the solid-liquid interface ranging from 200 6,000 Ks-1.

  12. Carbon formation and metal dusting in advanced coal gasification processes

    Energy Technology Data Exchange (ETDEWEB)

    DeVan, J.H.; Tortorelli, P.F.; Judkins, R.R.; Wright, I.G.

    1997-02-01

    The product gases generated by coal gasification systems contain high concentrations of CO and, characteristically, have relatively high carbon activities. Accordingly, carbon deposition and metal dusting can potentially degrade the operation of such gasifier systems. Therefore, the product gas compositions of eight representative gasifier systems were examined with respect to the carbon activity of the gases at temperatures ranging from 480 to 1,090 C. Phase stability calculations indicated that Fe{sub 3}C is stable only under very limited thermodynamic conditions and with certain kinetic assumptions and that FeO and Fe{sub 0.877}S tend to form instead of the carbide. As formation of Fe{sub 3}C is a necessary step in the metal dusting of steels, there are numerous gasifier environments where this type of carbon-related degradation will not occur, particularly under conditions associated with higher oxygen and sulfur activities. These calculations also indicated that the removal of H{sub 2}S by a hot-gas cleanup system may have less effect on the formation of Fe{sub 3}C in air-blown gasifier environments, where the iron oxide phase can exist and is unaffected by the removal of sulfur, than in oxygen-blown systems, where iron sulfide provides the only potential barrier to Fe{sub 3}C formation. Use of carbon- and/or low-alloy steels dictates that the process gas composition be such that Fe{sub 3}C cannot form if the potential for metal dusting is to be eliminated. Alternatively, process modifications could include the reintroduction of hydrogen sulfide, cooling the gas to perhaps as low as 400 C and/or steam injection. If higher-alloy steels are used, a hydrogen sulfide-free gas may be processed without concern about carbon deposition and metal dusting.

  13. Process of technology management in SMEs of the metal processing industry – the case study investigation

    Directory of Open Access Journals (Sweden)

    Krawczyk-Dembicka Elżbieta

    2017-03-01

    Full Text Available The main purpose of this work is to identify the factors that influence the process of technology management in the sector of small- and medium-sized enterprises of the metal processing industry, considering the shape and course required to achieve modern operation conditions by enterprises in the market.

  14. Process for producing metal oxide kernels and kernels so obtained

    International Nuclear Information System (INIS)

    Lelievre, Bernard; Feugier, Andre.

    1974-01-01

    The process desbribed is for producing fissile or fertile metal oxide kernels used in the fabrication of fuels for high temperature nuclear reactors. This process consists in adding to an aqueous solution of at least one metallic salt, particularly actinide nitrates, at least one chemical compound capable of releasing ammonia, in dispersing drop by drop the solution thus obtained into a hot organic phase to gel the drops and transform them into solid particles. These particles are then washed, dried and treated to turn them into oxide kernels. The organic phase used for the gel reaction is formed of a mixture composed of two organic liquids, one acting as solvent and the other being a product capable of extracting the anions from the metallic salt of the drop at the time of gelling. Preferably an amine is used as product capable of extracting the anions. Additionally, an alcohol that causes a part dehydration of the drops can be employed as solvent, thus helping to increase the resistance of the particles [fr

  15. Sustainability assessment of shielded metal arc welding (SMAW) process

    Science.gov (United States)

    Alkahla, Ibrahim; Pervaiz, Salman

    2017-09-01

    Shielded metal arc welding (SMAW) process is one of the most commonly employed material joining processes utilized in the various industrial sectors such as marine, ship-building, automotive, aerospace, construction and petrochemicals etc. The increasing pressure on manufacturing sector wants the welding process to be sustainable in nature. The SMAW process incorporates several types of inputs and output streams. The sustainability concerns associated with SMAW process are linked with the various input and output streams such as electrical energy requirement, input material consumptions, slag formation, fumes emission and hazardous working conditions associated with the human health and occupational safety. To enhance the environmental performance of the SMAW welding process, there is a need to characterize the sustainability for the SMAW process under the broad framework of sustainability. Most of the available literature focuses on the technical and economic aspects of the welding process, however the environmental and social aspects are rarely addressed. The study reviews SMAW process with respect to the triple bottom line (economic, environmental and social) sustainability approach. Finally, the study concluded recommendations towards achieving economical and sustainable SMAW welding process.

  16. Peculiarities of metal welding process modelling for the Arctic

    Science.gov (United States)

    Lagunov, Alexey; Fofanov, Andrey; Losunov, Anton

    2017-09-01

    M etal being rather tough has been used in the Arctic for a long time. In severe weather conditions metal construction is subject to strong corrosion and erosion. These processes affect the welds particular strongly. Violation of weld integrity leads to the different industrial accidents. Therefore, the welding quality is given such a strong focus. M ost high-quality welding is obtained if welding zone is provided with gas what eliminates the influence of oxygen on the process. But in this case it is very difficult to find the right concentration, gas pressure, direction of the jet. Study of the welding process using video and photography is expensive, in terms of money and time. Mathematical modelling of welding process using the program FlowVision enables to solve this issue at less cost. It's essential that obtained results qualitatively conform to the experimental ones and can be used in real application.

  17. Discontinuity Detection in the Shield Metal Arc Welding Process.

    Science.gov (United States)

    Cocota, José Alberto Naves; Garcia, Gabriel Carvalho; da Costa, Adilson Rodrigues; de Lima, Milton Sérgio Fernandes; Rocha, Filipe Augusto Santos; Freitas, Gustavo Medeiros

    2017-05-10

    This work proposes a new methodology for the detection of discontinuities in the weld bead applied in Shielded Metal Arc Welding (SMAW) processes. The detection system is based on two sensors-a microphone and piezoelectric-that acquire acoustic emissions generated during the welding. The feature vectors extracted from the sensor dataset are used to construct classifier models. The approaches based on Artificial Neural Network (ANN) and Support Vector Machine (SVM) classifiers are able to identify with a high accuracy the three proposed weld bead classes: desirable weld bead, shrinkage cavity and burn through discontinuities. Experimental results illustrate the system's high accuracy, greater than 90% for each class. A novel Hierarchical Support Vector Machine (HSVM) structure is proposed to make feasible the use of this system in industrial environments. This approach presented 96.6% overall accuracy. Given the simplicity of the equipment involved, this system can be applied in the metal transformation industries.

  18. Metal chelate process to remove pollutants from fluids

    Science.gov (United States)

    Chang, S.G.T.

    1994-12-06

    The present invention relates to improved methods using an organic iron chelate to remove pollutants from fluids, such as flue gas. Specifically, the present invention relates to a process to remove NO[sub x] and optionally SO[sub 2] from a fluid using a metal ion (Fe[sup 2+]) chelate wherein the ligand is a dimercapto compound wherein the --SH groups are attached to adjacent carbon atoms (HS--C--C--SH) or (SH--C--CCSH) and contain a polar functional group so that the ligand of DMC chelate is water soluble. Alternatively, the DMC is covalently attached to a water insoluble substrate such as a polymer or resin, e.g., polystyrene. The chelate is regenerated using electroreduction or a chemical additive. The dimercapto compound bonded to a water insoluble substrate is also useful to lower the concentration or remove hazardous metal ions from an aqueous solution. 26 figures.

  19. Parameters in selective laser melting for processing metallic powders

    Science.gov (United States)

    Kurzynowski, Tomasz; Chlebus, Edward; Kuźnicka, Bogumiła; Reiner, Jacek

    2012-03-01

    The paper presents results of studies on Selective Laser Melting. SLM is an additive manufacturing technology which may be used to process almost all metallic materials in the form of powder. Types of energy emission sources, mainly fiber lasers and/or Nd:YAG laser with similar characteristics and the wavelength of 1,06 - 1,08 microns, are provided primarily for processing metallic powder materials with high absorption of laser radiation. The paper presents results of selected variable parameters (laser power, scanning time, scanning strategy) and fixed parameters such as the protective atmosphere (argon, nitrogen, helium), temperature, type and shape of the powder material. The thematic scope is very broad, so the work was focused on optimizing the process of selective laser micrometallurgy for producing fully dense parts. The density is closely linked with other two conditions: discontinuity of the microstructure (microcracks) and stability (repeatability) of the process. Materials used for the research were stainless steel 316L (AISI), tool steel H13 (AISI), and titanium alloy Ti6Al7Nb (ISO 5832-11). Studies were performed with a scanning electron microscope, a light microscopes, a confocal microscope and a μCT scanner.

  20. Demonstration of pyrometallurgical processing for metal fuel and HLW

    International Nuclear Information System (INIS)

    Tadafumi, Koyama; Kensuke, Kinoshita; Takatoshi, Hizikata; Tadashi, Inoue; Ougier, M.; Rikard, Malmbeck; Glatz, J.P.; Lothar, Koch

    2001-01-01

    CRIEPI and JRC-ITU have started a joint study on pyrometallurgical processing to demonstrate the capability of this type of process for separating actinide elements from spent fuel and HLW. The equipment dedicated for this experiments has been developed and installed in JRC-ITU. The stainless steel box equipped with tele-manipulators is operated under pure Ar atmosphere, and prepared for later installation in a hot cell. Experiments on pyro-processing of un-irradiated U-Pu-Zr metal alloy fuel by molten salt electrorefining has been carried out. Recovery of U and Pu from this type alloy fuel was first demonstrated with using solid iron cathode and liquid Cd cathode, respectively. (author)

  1. Process Optimization for Valuable Metal Recovery from Dental Amalgam Residues

    Directory of Open Access Journals (Sweden)

    C.M. Parra–Mesa

    2009-07-01

    Full Text Available In this paper, the methodology used for optimizing leaching in a semi pilot plant is presented. This leaching process was applied to recover value metals from dental amalgam residues. 23 factorial design was used to characterize the process during the first stage and in the second one, a central compound rotational design was used for modeling copper percentage dissolved, a function of the nitric acid concentration, leaching time and temperature. This model explained the 81% of the response variability, which is considered satisfactory given the complexity of the process kinetics and, furthermore, it allowed the definition of the operation conditions for better copper recovery, which this was of 99.15%, at a temperature of 55°C, a concentration of 30% by weight and a time of 26 hours.

  2. Superior metallic alloys through rapid solidification processing (RSP) by design

    Energy Technology Data Exchange (ETDEWEB)

    Flinn, J.E. [Idaho National Engineering Laboratory, Idaho Falls, ID (United States)

    1995-05-01

    Rapid solidification processing using powder atomization methods and the control of minor elements such as oxygen, nitrogen, and carbon can provide metallic alloys with superior properties and performance compared to conventionally processing alloys. Previous studies on nickel- and iron-base superalloys have provided the baseline information to properly couple RSP with alloy composition, and, therefore, enable alloys to be designed for performance improvements. The RSP approach produces powders, which need to be consolidated into suitable monolithic forms. This normally involves canning, consolidation, and decanning of the powders. Canning/decanning is expensive and raises the fabrication cost significantly above that of conventional, ingot metallurgy production methods. The cost differential can be offset by the superior performance of the RSP metallic alloys. However, without the performance database, it is difficult to convince potential users to adopt the RSP approach. Spray casting of the atomized molten droplets into suitable preforms for subsequent fabrication can be cost competitive with conventional processing. If the fine and stable microstructural features observed for the RSP approach are preserved during spray casing, a cost competitive product can be obtained that has superior properties and performance that cannot be obtained by conventional methods.

  3. Processing of Refractory Metal Alloys for JOYO Irradiations

    International Nuclear Information System (INIS)

    RF Luther; ME Petrichek

    2006-01-01

    This is a summary of the refractory metal processing experienced by candidate Prometheus materiats as they were fabricated into specimens destined for testing within the JOYO test reactor, ex-reactor testing at Oak Ridge National Laboratory (ORNL), or testing within the NRPCT. The processing is described for each alloy from the point of inception to the point where processing was terminated due to the cancellation of Naval Reactor's involvement in the Prometheus Project. The alloys included three tantalum-base alloys (T-111, Ta-10W, and ASTAR-811C), a niobium-base alloy, (FS-85), and two molybdenum-rhenium alloys, one containing 44.5 w/o rhenium, and the other 47.5 w/o rhenium. Each of these alloys was either a primary candidate or back-up candidate for cladding and structural applications within the space reactor. Their production was intended to serve as a forerunner for large scale production ingots that were to be procured from commercial refractory metal vendors such as Wah Chang

  4. Regulable process for sawage electrochemical treatment from heavy metals

    International Nuclear Information System (INIS)

    Covaliov, V.; Covaliova, O.

    2004-01-01

    The invention relates to a process for sewage treatment and may be used in the protection for metal working, in particular, for electroplating. The disperse magnetic particle are obtaining in the comminution of the sintered spheric particle into a magnetilique faction block at the electrolyser at the outlet from the electrolyzer it is determined the suspension magnetization value concentration of the solid phase and the redox potential of the values it is automatically regulated the feed of magnetic particles and the current intensity correspondingly

  5. PM - processing for manufacturing of metals with cellular structures

    International Nuclear Information System (INIS)

    Strobl, S.; Danninger, H.

    2001-01-01

    In this review the major Processes about manufacturing of metals with cellular structure are described - based on powder metallurgy, chemical deposition and some other methods (without melting techniques). It can be shown that during the last decade many interesting innovations led to new production methods to design cellular materials. Some of them are used nowadays in industry. Also characterization and properties become more important and have therefore been carried out carefully, because of their strong influence on the functions and applications of such materials. (author)

  6. Metal matrix composite fabrication processes for high performance aerospace structures

    Science.gov (United States)

    Ponzi, C.

    A survey is conducted of extant methods of metal matrix composite (MMC) production in order to serve as a basis for prospective MMC users' selection of a matrix/reinforcement combination, cost-effective primary fabrication methods, and secondary fabrication techniques for the achievement of desired performance levels. Attention is given to the illustrative cases of structural fittings, control-surface connecting rods, hypersonic aircraft air inlet ramps, helicopter swash plates, and turbine rotor disks. Methods for technical and cost analysis modeling useful in process optimization are noted.

  7. VOLATILE CHLORIDE PROCESS FOR THE RECOVERY OF METAL VALUES

    Science.gov (United States)

    Hanley, W.R.

    1959-01-01

    A process is presented for recovering uranium, iron, and aluminum from centain shale type ores which contain uranium in minute quantities. The ore is heated wiih a chlorinating agent. such as chlorine, to form a volatilized stream of metal chlorides. The chloride stream is then passed through granular alumina which preferentially absorbs the volatile uranium chloride and from which the uranium may later be recovered. The remaining volatilized chlorides, chiefly those of iron and aluminum, are further treated to recover chlorine gas for recycle, and to recover ferric oxide and aluminum oxide as valuable by-products.

  8. Cleaning Process Development for Metallic Additively Manufactured Parts

    Science.gov (United States)

    Tramel, Terri L.; Welker, Roger; Lowery, Niki; Mitchell, Mark

    2014-01-01

    Additive Manufacturing of metallic components for aerospace applications offers many advantages over traditional manufacturing techniques. As a new technology, many aspects of its widespread utilization remain open to investigation. Among these are the cleaning processes that can be used for post finishing of parts and measurements to verify effectiveness of the cleaning processes. Many cleaning and drying processes and measurement methods that have been used for parts manufactured using conventional techniques are candidates that may be considered for cleaning and verification of additively manufactured parts. Among these are vapor degreasing, ultrasonic immersion and spray cleaning, followed by hot air drying, vacuum baking and solvent displacement drying. Differences in porosity, density, and surface finish of additively manufactured versus conventionally manufactured parts may introduce new considerations in the selection of cleaning and drying processes or the method used to verify their effectiveness. This presentation will review the relative strengths and weaknesses of different candidate cleaning and drying processes as they may apply to additively manufactured metal parts for aerospace applications. An ultrasonic cleaning technique for exploring the cleanability of parts will be presented along with an example using additively manufactured Inconel 718 test specimens to illustrate its use. The data analysis shows that this ultrasonic cleaning approach results in a well-behaved ultrasonic cleaning/extraction behavior. That is, it does not show signs of accelerated cavitation erosion of the base material, which was later confirmed by neutron imaging. In addition, the analysis indicated that complete cleaning would be achieved by ultrasonic immersion cleaning at approximately 5 minutes, which was verified by subsequent cleaning of additional parts.

  9. Novel Chemical Process for Producing Chrome Coated Metal

    Directory of Open Access Journals (Sweden)

    Christopher Pelar

    2018-01-01

    Full Text Available This work demonstrates that a version of the Reduction Expansion Synthesis (RES process, Cr-RES, can create a micron scale Cr coating on an iron wire. The process involves three steps. I. A paste consisting of a physical mix of urea, chrome nitrate or chrome oxide, and water is prepared. II. An iron wire is coated by dipping. III. The coated, and dried, wire is heated to ~800 °C for 10 min in a tube furnace under a slow flow of nitrogen gas. The processed wires were then polished and characterized, primarily with scanning electron microscopy (SEM. SEM indicates the chrome layer is uneven, but only on the scale of a fraction of a micron. The evidence of porosity is ambiguous. Elemental mapping using SEM electron microprobe that confirmed the process led to the formation of a chrome metal layer, with no evidence of alloy formation. Additionally, it was found that thickness of the final Cr layer correlated with the thickness of the precursor layer that was applied prior to the heating step. Potentially, this technique could replace electrolytic processing, a process that generates carcinogenic hexavalent chrome, but further study and development is needed.

  10. Novel Chemical Process for Producing Chrome Coated Metal.

    Science.gov (United States)

    Pelar, Christopher; Greenaway, Karima; Zea, Hugo; Wu, Chun-Hsien; Luhrs, Claudia C; Phillips, Jonathan

    2018-01-05

    This work demonstrates that a version of the Reduction Expansion Synthesis (RES) process, Cr-RES, can create a micron scale Cr coating on an iron wire. The process involves three steps. I. A paste consisting of a physical mix of urea, chrome nitrate or chrome oxide, and water is prepared. II. An iron wire is coated by dipping. III. The coated, and dried, wire is heated to ~800 °C for 10 min in a tube furnace under a slow flow of nitrogen gas. The processed wires were then polished and characterized, primarily with scanning electron microscopy (SEM). SEM indicates the chrome layer is uneven, but only on the scale of a fraction of a micron. The evidence of porosity is ambiguous. Elemental mapping using SEM electron microprobe that confirmed the process led to the formation of a chrome metal layer, with no evidence of alloy formation. Additionally, it was found that thickness of the final Cr layer correlated with the thickness of the precursor layer that was applied prior to the heating step. Potentially, this technique could replace electrolytic processing, a process that generates carcinogenic hexavalent chrome, but further study and development is needed.

  11. Process model for carbothermic production of silicon metal

    Energy Technology Data Exchange (ETDEWEB)

    Andresen, B.

    1995-09-12

    This thesis discusses an advanced dynamical two-dimensional cylinder symmetric model for the high temperature part of the carbothermic silicon metal process, and its computer encoding. The situation close to that which is believed to exist around one of three electrodes in full-scale industrial furnaces is modelled. This area comprises a gas filled cavity surrounding the lower tip of the electrode, the metal pool underneath and the lower parts of the materials above. The most important phenomena included are: Heterogeneous chemical reactions taking place in the high-temperature zone (above 1860 {sup o}C), Evaporation and condensation of silicon, Transport of materials by dripping, Turbulent or laminar fluid flow, DC electric arcs, Heat transport by convection, conduction and radiation. The results from the calculations, such as production rates, gas- and temperature distributions, furnace- and particle geometries, fluid flow fields etc, are presented graphically. In its present state the model is a prototype. The process is very complex, and the calculations are time consuming. The governing equations are coded into a Fortran 77 computer code applying the commercial 3D code FLUENT as a basis. 64 refs., 110 figs., 11 tabs.

  12. Relative importance of cohesion and adhesion for sensory stickiness of semisolid foods

    NARCIS (Netherlands)

    Dunnewind, B.; Janssen, A.M.; Vliet, T. van; Weenen, H.

    2004-01-01

    The relative importance of cohesion and adhesion for sensory stickness of semisolid foods was investigated using a texture analyzers. Products included commercial mayon-naises, custard desserts and warm sauces which varied in apparent viscosity between 0.3 and 18.3 Pa.s. It was observed that the

  13. Tribological properties of rice starch in liquid and semi-solid food model systems

    NARCIS (Netherlands)

    Liu, K.; Stieger, M.A.; Linden, van der E.; Velde, van de Fred

    2016-01-01

    This study investigated the tribological and rheological properties of liquid and semi-solid food model systems containing micro-granular rice starch. Native (uncooked) and gelatinized rice starch dispersions, o/w emulsions and emulsion-filled gelatin gels were studied as food model systems. Native

  14. The effect of saliva composition on texture perception of semi-solids

    NARCIS (Netherlands)

    Engelen, L.; Keybus, P.A.M. van den; Wijk, R.A. de; Veerman, E.C.I.; Amerongen, A.V.N.; Bosman, F.; Prinz, J.F.; Bilt, A. van der

    2007-01-01

    Saliva is expected to be of significance for the perception of food stimuli in the mouth. Mixing the food with saliva, including breakdown and dilution, is considered to be of large importance for semi-solids as these products are masticated without chewing. It is known that there are large

  15. Instrumental and sensory quantification of oral coatings retained after swallowing semi-solid foods

    NARCIS (Netherlands)

    Prinz, J.F.; Huntjens, L.; Wijk, de R.A.

    2006-01-01

    After a mouthful of food has been swallowed, some food material is always retained in the mouth. With semi-solid foods this is in the form of a coating that adheres to the oral mucosa. The amount and location of this material may play an important role in food sensations. In this study two

  16. Removal and recovery of metal ions from process and waste streams using polymer filtration

    International Nuclear Information System (INIS)

    Jarvinen, G.D.; Smith, B.F.; Robison, T.W.; Kraus, K.M.; Thompson, J.A.

    1999-01-01

    Polymer Filtration (PF) is an innovative, selective metal removal technology. Chelating, water-soluble polymers are used to selectively bind the desired metal ions and ultrafiltration is used to concentrate the polymer-metal complex producing a permeate with low levels of the targeted metal ion. When applied to the treatment of industrial metal-bearing aqueous process streams, the permeate water can often be reused within the process and the metal ions reclaimed. This technology is applicable to many types of industrial aqueous streams with widely varying chemistries. Application of PF to aqueous streams from nuclear materials processing and electroplating operations will be described

  17. 3D finite element modelling of sheet metal blanking process

    Science.gov (United States)

    Bohdal, Lukasz; Kukielka, Leon; Chodor, Jaroslaw; Kulakowska, Agnieszka; Patyk, Radoslaw; Kaldunski, Pawel

    2018-05-01

    The shearing process such as the blanking of sheet metals has been used often to prepare workpieces for subsequent forming operations. The use of FEM simulation is increasing for investigation and optimizing the blanking process. In the current literature a blanking FEM simulations for the limited capability and large computational cost of the three dimensional (3D) analysis has been largely limited to two dimensional (2D) plane axis-symmetry problems. However, a significant progress in modelling which takes into account the influence of real material (e.g. microstructure of the material), physical and technological conditions can be obtained by using 3D numerical analysis methods in this area. The objective of this paper is to present 3D finite element analysis of the ductile fracture, strain distribution and stress in blanking process with the assumption geometrical and physical nonlinearities. The physical, mathematical and computer model of the process are elaborated. Dynamic effects, mechanical coupling, constitutive damage law and contact friction are taken into account. The application in ANSYS/LS-DYNA program is elaborated. The effect of the main process parameter a blanking clearance on the deformation of 1018 steel and quality of the blank's sheared edge is analyzed. The results of computer simulations can be used to forecasting quality of the final parts optimization.

  18. Gastric Emptying of Elemental Liquid Diets Versus Semisolid Diets in Bedridden Gastrostomy-fed Patients.

    Science.gov (United States)

    Horiuchi, Akira; Sakai, Ryosei; Tamaki, Michio; Kajiyama, Masashi; Tanaka, Naoki; Morikawa, Akio

    2018-03-21

    Aspiration is a common problem in bedridden gastrostomy-fed patients. We compared gastric emptying of an elemental liquid diet and a commercial semisolid diet in bedridden gastrostomy-fed patients. Study 1: from January 2013 to December 2016, consecutive bedridden patients receiving percutaneous endoscopic gastrostomy (PEG) semisolid feeding hospitalized due to aspiration pneumonia were switched to elemental liquid diet feedings. The frequency of defecation, tube feed contents aspirated from the trachea, and aspiration pneumonia during hospitalization were retrospectively reviewed. Study 2 was a randomized, crossover trial comparing C sodium acetate gastric emptying of a commercial elemental liquid or a commercial semisolid diet in bedridden PEG patients and controls. Study 1: 18 patients were enrolled. Elemental liquid diet was aspirated from the trachea in 1 (5.6%) (once in 24 observations); neither aspiration pneumonia nor diarrhea developed during elemental liquid diet feeding over 2 weeks observation. Study 2: 8 PEG patients and 8 healthy subjects were separately randomized to assess gastric emptying of the commercial elemental and semisolid diets. The elemental liquid diet was associated with a significant decrease of the 10%, 30%, or 50% emptying (excretion) time (Pbedridden PEG patients. They may prevent or reduce aspiration pneumonia compared with semisolid diets.This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CCBY-NC-ND), where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially without permission from the journal. http://creativecommons.org/licenses/by-nc-nd/4.0/.

  19. Workplace exposure to nanoparticles from gas metal arc welding process

    International Nuclear Information System (INIS)

    Zhang, Meibian; Jian, Le; Bin, Pingfan; Xing, Mingluan; Lou, Jianlin; Cong, Liming; Zou, Hua

    2013-01-01

    Workplace exposure to nanoparticles from gas metal arc welding (GMAW) process in an automobile manufacturing factory was investigated using a combination of multiple metrics and a comparison with background particles. The number concentration (NC), lung-deposited surface area concentration (SAC), estimated SAC and mass concentration (MC) of nanoparticles produced from the GMAW process were significantly higher than those of background particles before welding (P < 0.01). A bimodal size distribution by mass for welding particles with two peak values (i.e., 10,000–18,000 and 560–320 nm) and a unimodal size distribution by number with 190.7-nm mode size or 154.9-nm geometric size were observed. Nanoparticles by number comprised 60.7 % of particles, whereas nanoparticles by mass only accounted for 18.2 % of the total particles. The morphology of welding particles was dominated by the formation of chain-like agglomerates of primary particles. The metal composition of these welding particles consisted primarily of Fe, Mn, and Zn. The size distribution, morphology, and elemental compositions of welding particles were significantly different from background particles. Working activities, sampling distances from the source, air velocity, engineering control measures, and background particles in working places had significant influences on concentrations of airborne nanoparticle. In addition, SAC showed a high correlation with NC and a relatively low correlation with MC. These findings indicate that the GMAW process is able to generate significant levels of nanoparticles. It is recommended that a combination of multiple metrics is measured as part of a well-designed sampling strategy for airborne nanoparticles. Key exposure factors, such as particle agglomeration/aggregation, background particles, working activities, temporal and spatial distributions of the particles, air velocity, engineering control measures, should be investigated when measuring workplace

  20. Alkali and heavy metals emissions of the PCFB-process

    International Nuclear Information System (INIS)

    Kuivalainen, R.; Eriksson, T.; Koskinen, J.; Lehtonen, P.

    1995-01-01

    Pressurized Circulating Fluidized Bed (PCFB) combustion technology has been developed by A. Ahlstrom Corporation since 1986. As a part of the development, a 10 MV PCFB Test Facility was constructed at Hans Ahlstrom Laboratory in Karhula, Finland in 1989. The Test Facility has been used for performance testing with different coal types through the years 1990-1994 for obtaining data for design and commercialization of the high-efficiency low-emission PCFB combustion technology. The project Y44 'Alkali and heavy metal emissions of the PCFB-process' is part of national LIEKKI 2 research program and it continues the work started under alkali measurement project Y33 in 1994. The objective of the project is to measure vapor phase alkali and heavy metal concentrations in the PCFB flue gas after high-temperature high-pressure particulate filter and to investigate the effects of process conditions and sorbents on alkali release. The measured Na concentrations were between 0,03 and 0,21 ppm(w). The results of K were between 0,01 and 0,08 ppm(w). The accuracy of the results is about +-50 percent at this concentration range. The scatter of the data covers the effects of different process variables on the alkali emission. The measured emissions at 800-850 deg C are at the same order of magnitude as the guideline emission limits given by gas turbine manufacturers for flue gas at 1000-1200 deg C. The measurements and development of the analyses methods are planned to be continued during PCFB test runs in autumn 1995 in cooperation with laboratories of VTT Energy and Tampere University of Technology. (author)

  1. Workplace exposure to nanoparticles from gas metal arc welding process

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Meibian [Zhejiang Provincial Center for Disease Control and Prevention (China); Jian, Le [Curtin University of Technology, School of Public Health, Curtin Health Innovation Research Institute (Australia); Bin, Pingfan [Wujin District Center for Disease Control and Prevention (China); Xing, Mingluan [Zhejiang Provincial Center for Disease Control and Prevention (China); Lou, Jianlin [Zhejiang Academy of Medical Sciences (China); Cong, Liming; Zou, Hua, E-mail: hzou@cdc.zj.cn [Zhejiang Provincial Center for Disease Control and Prevention (China)

    2013-11-15

    Workplace exposure to nanoparticles from gas metal arc welding (GMAW) process in an automobile manufacturing factory was investigated using a combination of multiple metrics and a comparison with background particles. The number concentration (NC), lung-deposited surface area concentration (SAC), estimated SAC and mass concentration (MC) of nanoparticles produced from the GMAW process were significantly higher than those of background particles before welding (P < 0.01). A bimodal size distribution by mass for welding particles with two peak values (i.e., 10,000–18,000 and 560–320 nm) and a unimodal size distribution by number with 190.7-nm mode size or 154.9-nm geometric size were observed. Nanoparticles by number comprised 60.7 % of particles, whereas nanoparticles by mass only accounted for 18.2 % of the total particles. The morphology of welding particles was dominated by the formation of chain-like agglomerates of primary particles. The metal composition of these welding particles consisted primarily of Fe, Mn, and Zn. The size distribution, morphology, and elemental compositions of welding particles were significantly different from background particles. Working activities, sampling distances from the source, air velocity, engineering control measures, and background particles in working places had significant influences on concentrations of airborne nanoparticle. In addition, SAC showed a high correlation with NC and a relatively low correlation with MC. These findings indicate that the GMAW process is able to generate significant levels of nanoparticles. It is recommended that a combination of multiple metrics is measured as part of a well-designed sampling strategy for airborne nanoparticles. Key exposure factors, such as particle agglomeration/aggregation, background particles, working activities, temporal and spatial distributions of the particles, air velocity, engineering control measures, should be investigated when measuring workplace

  2. The influence of heavy metals on the production of extracellular polymer substances in the processes of heavy metal ions elimination.

    Science.gov (United States)

    Mikes, J; Siglova, M; Cejkova, A; Masak, J; Jirku, V

    2005-01-01

    Wastewaters from a chemical industry polluted by heavy metal ions represent a hazard for all living organisms. It can mean danger for ecosystems and human health. New methods are sought alternative to traditional chemical and physical processes. Active elimination process of heavy metals ions provided by living cells, their components and extracellular products represents a potential way of separating toxic heavy metals from industrial wastewaters. While the abilities of bacteria to remove metal ions in solution are extensively used, fungi have been recognized as a promising kind of low-cost adsorbents for removal of heavy-metal ions from aqueous waste sources. Yeasts and fungi differ from each other in their constitution and in their abilities to produce variety of extracellular polymeric substances (EPS) with different mechanisms of metal interactions. The accumulation of Cd(2+), Cr(6+), Pb(2+), Ni(2+) and Zn(2+) by yeasts and their EPS was screened at twelve different yeast species in microcultivation system Bioscreen C and in the shaking Erlenmayer's flasks. This results were compared with the production of yeast EPS and the composition of yeast cell walls. The EPS production was measured during the yeast growth and cell wall composition was studied during the cultivations in the shaking flasks. At the end of the process extracellular polymers and their chemical composition were isolated and amount of bound heavy metals was characterized. The variable composition and the amount of the EPS were found at various yeast strains. It was influenced by various compositions of growth medium and also by various concentrations of heavy metals. It is evident, that the amount of bound heavy metals was different. The work reviews the possibilities of usage of various yeast EPS and components of cell walls in the elimination processes of heavy metal ions. Further the structure and properties of yeasts cell wall and EPS were discussed. The finding of mechanisms mentioned

  3. Contaminated Metal Components in Dismantling by Hot Cutting Processes

    International Nuclear Information System (INIS)

    Cesari, Franco G.; Conforti, Gianmario; Rogante, Massimo; Giostri, Angelo

    2006-01-01

    During the preparatory dismantling activities of Caorso's Nuclear Power Plant (NPP), an experimental campaign using plasma and oxyacetylene metal cutting processes has been performed and applied to plates and tubes exposed to the coolant steam of the reactor. The plant (Boiling Water Reactor, 870 MWe) was designed and built in the 70's, and it was fully operating by 1981 to 1986 being shut down after 1987 Italy's poll that abrogated nuclear power based on U235 fission. The campaign concerns no activated materials, even if the analyses have been performed of by use contaminated components under the free release level, not yet taking into account radioactivity. In this paper, the parameters related to inhalable aerosol, solid and volatile residuals production have been, studied during hot processes which applies the same characteristics of the cutting in field for the dismantling programs of Caorso NPP. The technical parameters such as cutting time and cutting rate vs. pipe diameter/thickness/schedule or plate thickness for ferritic alloys and the emissions composition coming from the sectioning are also reported. The results underline the sort of trouble that can emerge in the cutting processes, in particular focusing on the effects comparison between the two cutting processes and the chemical composition of powders captured by filtering the gaseous emission. Some preliminary considerations on methodology to be used during the dismantling have been presented. (authors)

  4. Pyrometallurgical processing of Integral Fast Reactor metal fuels

    International Nuclear Information System (INIS)

    Battles, J.E.; Miller, W.E.; Gay, E.C.

    1991-01-01

    The pyrometallurgical process for recycling spent metal fuels from the Integral Fast Reactor is now in an advanced state of development. This process involves electrorefining spent fuel with a cadmium anode, solid and liquid cathodes, and a molten salt electrolyte (LiCl-KCl) at 500 degrees C. The initial process feasibility and flowsheet verification studies have been conducted in a laboratory-scale electrorefiner. Based on these studies, a dual cathode approach has been adopted, where uranium is recovered on a solid cathode mandrel and uranium-plutonium is recovered in a liquid cadmium cathode. Consolidation and purification (salt and cadmium removal) of uranium and uranium-plutonium products from the electrorefiner have been successful. The process is being developed with the aid of an engineering-scale electrorefiner, which has been successfully operated for more than three years. In this electrorefiner, uranium has been electrotransported from the cadmium anode to a solid cathode in 10 kg quantities. Also, anodic dissolution of 10 kg batches of chopped, simulated fuel (U--10% Zr) has been demonstrated. Development of the liquid cadmium cathode for recovering uranium-plutonium is under way

  5. Process for recovering uranium and other base metals

    International Nuclear Information System (INIS)

    Jan, R. J-J.

    1979-01-01

    Uranium and other base metals are leached from their ores with aqueous solutions containing bicarbonate ions that have been generated or reconstituted by converting other non-bicarbonate anions into bicarbonate ions. The conversion is most conveniently effected by contacting solutions containing SO 4 - and Cl - ions with a basic anion exchange resin so that the SO 4 - and Cl - ions are converted into or exhanged for HCO 3 - ions. CO 2 may be dissolved in the solution so it is present during the exhange. The resin is preferably in bicarbonate form prior to contact and CO 2 partial pressure is adjusted so that the resin is not fouled by depositing metal precipitates. In-situ uranium mining is conducted by circulating such solutions through the ore deposit. Oxidizing agents are included in the injected lixiviant. The leaching strength of the circulating bicarbonate lixiviant is maintained by converting the anions generated during leaching or above-ground recovery processes into HCO 3 - ions. The resin may conveniently be eluted and reformed intermittently

  6. Process for recovering uranium and other base metals

    International Nuclear Information System (INIS)

    Jan, R.J.

    1981-01-01

    Uranium and other base metals are leached from their ores with aqueous solutions containing bicarbonate ions that have been generated or reconstituted by converting other non-bicarbonate anions into bicarbonate ions. The conversion is most conveniently effected by contacting solutions containing SO 4 -- and C1 - ions with a basic anion exchange resin so that the SO 4 -- and Cl - ions are converted into or exchanged for HCO 3 - ions. CO 2 may be dissolved in the solution so it is present during the exchange. The resin is preferably in bicarbonate form prior to contact and CO 2 partial pressure is adjusted so that the resin is not fouled by depositing metal precipitates. In-situ uranium mining is conducted by circulating such solutions through the ore deposit. Oxidizing agents are included in the injected lixiviant. The leaching strength of the circulating bicarbonate lixiviant is maintained by converting the anions generated during leaching or above-ground recovery processes into HCO 3 - ions. The resin may conveniently be eluted and performed intermittently. (author)

  7. Process for recovering uranium and other base metals

    International Nuclear Information System (INIS)

    Jan, R.J.

    1984-01-01

    Uranium and other base metals are leached from their ores with aqueous solutions containing bicarbonate ions that have been generated or reconstituted by converting other non-bicarbonate anions into bicarbonate ions. The conversion is most conveniently effected by contacting solutions containing SO 4 2- and Cl - ions with a basic anion exchange resin so that the SO 4 2- and Cl - ions are converted into or exchanged for HCO 3 - ions. CO 2 may be dissolved in the solution so it is present during the exchange. The resin is preferably in bicarbonate form prior to contact and CO 2 partial pressure is adjusted so that the resin is not fouled by depositing metal precipitates. In-situ uranium mining is conducted by circulating such solutions through the ore deposit. Oxidizing agents are included in the injected lixiviant. The leaching strength of the circulating bicarbonate lixiviant is maintained by converting the anions generated during leaching or above-ground recovery processes into HCO 3 - ions. The resin may conveniently be eluted and reformed intermittently

  8. Hydrodynamics of heavy liquid metal coolant processes and filtering apparatus

    International Nuclear Information System (INIS)

    Albert K Papovyants; Yuri I Orlov; Pyotr N Martynov; Yuri D Boltoev

    2005-01-01

    to S ≤ 0,2 d p . It is demonstrated that the filtration efficiency can be significantly influenced by the properties of the capillary-porous structure of the filter material: the fiber diameter, type of braiding providing the availability of stagnant zones, porosity and wetting angle. With some simplifying prerequisites, the evaluation of the dynamics of the sedimentation growth on the porous partition has been performed as a function of time. Analysis of the conditions of the hydrodynamic separation of filter entrained particles (d p ≅ 2 μm) by the coolant flow revealed that to realize this process, it is necessary that the wall flow velocity be about V = 0,2 m/s. The object of investigations was a broad class of filter materials, including metallo-ceramics, metallic grids, carbon cloth, glass-fibers, needle-pierced cloth made of metallic fibers, grainy materials (made of aluminium oxides). By the complex of technical characteristics, with the thermal stability, cleaning efficiency (fineness), impurity retention capacity and hydraulic resistance considered, the multi-layer siliceous textured cloth (SiO 2 >95%, t 400 deg. C) and needle-pierced cloth made of 40 μm-d. metallic fibers (X18H10T steel, t ≤ 400-550 deg. C) are recommended for HLMC cleaning. The routine monitoring of the filter operation is implemented based on its resistance and the reduction of the flow rate through the filter, induced by its clogging by impurities, the clogging being dependent on the concentration of suspensions in coolant. The investigations as conducted made it possible to construct high temperature filter specimens, including those for an output capacity of 900 m 3 /h, in reference to operation and maintenance conditions of heavy liquid metal cooled nuclear power installations. (authors)

  9. Codeformation processing of mechanically-dissimilar metal/intermetallic composites

    Science.gov (United States)

    Marte, Judson Sloan

    A systematic and scientific approach has been applied to the study of codeformation processing. A series of composites having mechanically-dissimilar phases were developed in which the high temperature flow behavior of the reinforcement material could be varied independent of the matrix. This was accomplished through the use of a series of intermetallic matrix composites (IMCs) as discontinuous reinforcements in an otherwise conventional metal matrix composite. The IMCs are produced using an in-situ reaction synthesis technique, called the XD(TM) process. The temperature of the exothermic synthesis reaction, called the adiabatic temperature, has been calculated and shown to increase with increasing volume percentage of TiB2 reinforcement. Further, this temperature has been shown to effect the size and spacing of the TiB2, microstructural features which are often used in discontinuous composite strength models. Study of the high temperature flow behavior of the components of the metal/IMC composite is critical to the development of an understanding of codeformation. A series of compression tests performed at 1000° to 1200°C and strain-rates of 10-3 and 10-4 sec-1. Peak flow stresses were used to evaluate the influence of material properties and process conditions. These data were incorporated into phenomenologically-based constitutive equations that have been used to predict the flow behavior. It has been determined that plastic deformation of the IMCs occurs readily, and is largely TiB2 independent, at temperatures approaching the melting point of the intermetallic matrices. Ti-6Al-4V/IMC powder blends were extruded at high temperatures to achieve commensurately deformed microstructures. The results of codeformation processing were analyzed in terms of the plastic strain of the IMC particulates. IMC particle deformation was shown to increase with increasing IMC particle size, volume percentage of IMC, extrusion temperature, homologous temperature, extrusion

  10. Enhancement of surface integrity of titanium alloy with copper by means of laser metal deposition process

    CSIR Research Space (South Africa)

    Erinosho, MF

    2016-04-01

    Full Text Available The laser metal deposition process possesses the combination of metallic powder and laser beam respectively. However, these combinations create an adhesive bonding that permanently solidifies the laser-enhanced-deposited powders. Titanium alloys (Ti...

  11. Process for treating waste water having low concentrations of metallic contaminants

    Science.gov (United States)

    Looney, Brian B; Millings, Margaret R; Nichols, Ralph L; Payne, William L

    2014-12-16

    A process for treating waste water having a low level of metallic contaminants by reducing the toxicity level of metallic contaminants to an acceptable level and subsequently discharging the treated waste water into the environment without removing the treated contaminants.

  12. Metal Advanced Manufacturing Bot-Assisted Assembly (MAMBA) Process, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Tethers Unlimited, Inc. (TUI) proposes to develop the Metal Advanced Manufacturing Bot-Assisted Assembly (MAMBA) Process, a robotically managed metal press and...

  13. 279 Watt Metal-Wrap-Through module using industrial processes

    Energy Technology Data Exchange (ETDEWEB)

    Guillevin, N.; Heurtault, B.; Geerligs, L.J.; Anker, J.; Van Aken, B.B.; Bennett, I.J.; Jansen, M.J.; Berkeveld, L.D.; Weeber, A.W.; Bultman, J.H. [ECN Solar Energy, PO Box 1, 1755 ZG Petten (Netherlands); Wenchao, Zhao; Jianming, Wang; Ziqian, Wang; Yingle, Chen; Yanlong, Shen; Zhiyan, Hu; Gaofei, Li; Jianhui, Chen; Bo, Yu; Shuquan, Tian; Jingfeng, Xiong [Yingli Solar, 3399 Chaoyang North Street, Baoding (China)

    2012-09-15

    This paper describes results of metal wrap through (MWT) cells produced from n-type Czochralski silicon wafers, and modules produced from those cells. The use of n-type silicon as base material allows for high efficiencies: for front emitter contacted industrial cells, efficiencies up to 20% have been reported. MWT cells allow even higher cell efficiency due to reduced front metal coverage, and additionally full back-contacting of the MWT cells in a module results in reduced cell to module (CTM) fill factor losses. MWT cells were produced by industrial process technologies. The efficiency of the MWT cells reproducibly exceeds the efficiency of front contact cells based on the same technology by about 0.2-0.3%, and routes for further improvement are analyzed. 60-cell modules were produced from both types of cells (MWT and H-pattern front emitter). In a direct module performance comparison, the MWT module, based on integrated backfoil, produced 3% higher power output than the comparable tabbed front emitter contact module. CTM current differences arise from the higher packing density, and in this experiment from a lower reflectance of the backfoil, in MWT modules. CTM FF differences are related to resistive losses in copper circuitry on the backfoil versus tabs. The CTM FF loss of the MWT module was reduced by 2.2%abs compared to the tabbed front emitter contact module. Finally, simple process optimizations were tested to improve the n-type MWT cell and module efficiency. A module made using MWT cells of 19.6% average efficiency resulted in a power output of 279W. The cell and module results are analyzed and routes for improvements are discussed.

  14. Salts of alkali metal anions and process of preparing same

    Science.gov (United States)

    Dye, James L.; Ceraso, Joseph M.; Tehan, Frederick J.; Lok, Mei Tak

    1978-01-01

    Compounds of alkali metal anion salts of alkali metal cations in bicyclic polyoxadiamines are disclosed. The salts are prepared by contacting an excess of alkali metal with an alkali metal dissolving solution consisting of a bicyclic polyoxadiamine in a suitable solvent, and recovered by precipitation. The salts have a gold-color crystalline appearance and are stable in a vacuum at -10.degree. C. and below.

  15. Process for the preparation of fine grain metal carbide powders

    International Nuclear Information System (INIS)

    Gortsema, F.P.

    1976-01-01

    Fine grain metal carbide powders are conveniently prepared from the corresponding metal oxide by heating in an atmosphere of methane in hydrogen. Sintered articles having a density approaching the theoretical density of the metal carbide itself can be fabricated from the powders by cold pressing, hot pressing or other techniques. 8 claims, no drawings

  16. Research process of nondestructive testing pitting corrosion in metal material

    Directory of Open Access Journals (Sweden)

    Bo ZHANG

    2017-12-01

    Full Text Available Pitting corrosion directly affects the usability and service life of metal material, so the effective nondestructive testing and evaluation on pitting corrosion is of great significance for fatigue life prediction because of data supporting. The features of pitting corrosion are elaborated, and the relation between the pitting corrosion parameters and fatigue performance is pointed out. Through introducing the fundamental principles of pitting corrosion including mainly magnetic flux leakage inspection, pulsed eddy current and guided waves, the research status of nondestructive testing technology for pitting corrosion is summarized, and the key steps of nondestructive testing technologies are compared and analyzed from the theoretical model, signal processing to industrial applications. Based on the analysis of the signal processing specificity of different nondestructive testing technologies in detecting pitting corrosion, the visualization combined with image processing and signal analysis are indicated as the critical problems of accurate extraction of pitting defect information and quantitative characterization for pitting corrosion. The study on non-contact nondestructive testing technologies is important for improving the detection precision and its application in industries.

  17. Sequential optimization and reliability assessment method for metal forming processes

    International Nuclear Information System (INIS)

    Sahai, Atul; Schramm, Uwe; Buranathiti, Thaweepat; Chen Wei; Cao Jian; Xia, Cedric Z.

    2004-01-01

    Uncertainty is inevitable in any design process. The uncertainty could be due to the variations in geometry of the part, material properties or due to the lack of knowledge about the phenomena being modeled itself. Deterministic design optimization does not take uncertainty into account and worst case scenario assumptions lead to vastly over conservative design. Probabilistic design, such as reliability-based design and robust design, offers tools for making robust and reliable decisions under the presence of uncertainty in the design process. Probabilistic design optimization often involves double-loop procedure for optimization and iterative probabilistic assessment. This results in high computational demand. The high computational demand can be reduced by replacing computationally intensive simulation models with less costly surrogate models and by employing Sequential Optimization and reliability assessment (SORA) method. The SORA method uses a single-loop strategy with a series of cycles of deterministic optimization and reliability assessment. The deterministic optimization and reliability assessment is decoupled in each cycle. This leads to quick improvement of design from one cycle to other and increase in computational efficiency. This paper demonstrates the effectiveness of Sequential Optimization and Reliability Assessment (SORA) method when applied to designing a sheet metal flanging process. Surrogate models are used as less costly approximations to the computationally expensive Finite Element simulations

  18. System and process for aluminization of metal-containing substrates

    Energy Technology Data Exchange (ETDEWEB)

    Chou, Yeong-Shyung; Stevenson, Jeffry W.

    2017-12-12

    A system and method are detailed for aluminizing surfaces of metallic substrates, parts, and components with a protective alumina layer in-situ. Aluminum (Al) foil sandwiched between the metallic components and a refractory material when heated in an oxidizing gas under a compression load at a selected temperature forms the protective alumina coating on the surface of the metallic components. The alumina coating minimizes evaporation of volatile metals from the metallic substrates, parts, and components in assembled devices that can degrade performance during operation at high temperature.

  19. System and process for aluminization of metal-containing substrates

    Science.gov (United States)

    Chou, Yeong-Shyung; Stevenson, Jeffry W

    2015-11-03

    A system and method are detailed for aluminizing surfaces of metallic substrates, parts, and components with a protective alumina layer in-situ. Aluminum (Al) foil sandwiched between the metallic components and a refractory material when heated in an oxidizing gas under a compression load at a selected temperature forms the protective alumina coating on the surface of the metallic components. The alumina coating minimizes evaporation of volatile metals from the metallic substrates, parts, and components in assembled devices during operation at high temperature that can degrade performance.

  20. Preparation of magnesium metal matrix composites by powder metallurgy process

    Science.gov (United States)

    Satish, J.; Satish, K. G., Dr.

    2018-02-01

    Magnesium is the lightest metal used as the source for constructional alloys. Today Magnesium based metal matrix composites are widely used in aerospace, structural, oceanic and automobile applications for its light weight, low density(two thirds that of aluminium), good high temperature mechanical properties and good to excellent corrosion resistance. The reason of designing metal matrix composite is to put in the attractive attributes of metals and ceramics to the base metal. In this study magnesium metal matrix hybrid composite are developed by reinforcing pure magnesium with silicon carbide (SiC) and aluminium oxide by method of powder metallurgy. This method is less expensive and very efficient. The Hardness test was performed on the specimens prepared by powder metallurgy method. The results revealed that the micro hardness of composites was increased with the addition of silicon carbide and alumina particles in magnesium metal matrix composites.

  1. Rejuvenation of residual oil hydrotreating catalysts by leaching of foulant metals. Modelling of the metal leaching process

    Energy Technology Data Exchange (ETDEWEB)

    Marafi, M.; Kam, E.K.T.; Stanislaus, A.; Absi-Halabi, M. [Petroleum Technology Department, Petroleum, Petrochemicals and Materials Division, Kuwait Institute for Scientific Research, Safat (Kuwait)

    1996-11-19

    Increasing emphasis has been paid in recent years on the development of processes for the rejuvenation of spent residual oil hydroprocessing catalysts, which are deactivated by deposition of metals (e.g. vanadium) and coke. As part of a research program on this subject, we have investigated selective removal of the major metal foulant from the spent catalyst by chemical leaching. In the present paper, we report the development of a model for foulant metals leaching from the spent catalyst. The leaching process is considered to involve two consecutive operations: (1) removal of metal foulants along the main mass transfer channels connected to the narrow pores until the pore structure begins to develop and (2) removal of metal foulants from the pore structure. Both kinetic and mass transfer aspects were considered in the model development, and a good agreement was noticed between experimental and simulated results

  2. Knowledge Based Cloud FE Simulation of Sheet Metal Forming Processes.

    Science.gov (United States)

    Zhou, Du; Yuan, Xi; Gao, Haoxiang; Wang, Ailing; Liu, Jun; El Fakir, Omer; Politis, Denis J; Wang, Liliang; Lin, Jianguo

    2016-12-13

    The use of Finite Element (FE) simulation software to adequately predict the outcome of sheet metal forming processes is crucial to enhancing the efficiency and lowering the development time of such processes, whilst reducing costs involved in trial-and-error prototyping. Recent focus on the substitution of steel components with aluminum alloy alternatives in the automotive and aerospace sectors has increased the need to simulate the forming behavior of such alloys for ever more complex component geometries. However these alloys, and in particular their high strength variants, exhibit limited formability at room temperature, and high temperature manufacturing technologies have been developed to form them. Consequently, advanced constitutive models are required to reflect the associated temperature and strain rate effects. Simulating such behavior is computationally very expensive using conventional FE simulation techniques. This paper presents a novel Knowledge Based Cloud FE (KBC-FE) simulation technique that combines advanced material and friction models with conventional FE simulations in an efficient manner thus enhancing the capability of commercial simulation software packages. The application of these methods is demonstrated through two example case studies, namely: the prediction of a material's forming limit under hot stamping conditions, and the tool life prediction under multi-cycle loading conditions.

  3. Development of electrolytic process in molten salt media for light rare-earth metals production. The metallic cerium electrodeposition

    International Nuclear Information System (INIS)

    Restivo, T.A.G.

    1994-01-01

    The development of molten salt process and the respective equipment aiming rare-earth metals recovery was described. In the present case, the liquid cerium metal electrodeposition in a molten electrolytes of cerium chloride and an equimolar mixture of sodium and potassium chlorides in temperatures near 800 C was studied. Due the high chemical reactivity of the rare-earth metals in the liquid state and their molten halides, an electrolytic cell was constructed with controlled atmosphere, graphite crucibles and anodes and a tungsten cathode. The electrolytic process variables and characteristics were evaluated upon the current efficiency and metallic product purity. Based on this evaluations, were suggested some alterations on the electrolytic reactor design and upon the process parameters. (author). 90 refs, 37 figs, 20 tabs

  4. Process for recovering tritium from molten lithium metal

    Science.gov (United States)

    Maroni, Victor A.

    1976-01-01

    Lithium tritide (LiT) is extracted from molten lithium metal that has been exposed to neutron irradiation for breeding tritium within a thermonuclear or fission reactor. The extraction is performed by intimately contacting the molten lithium metal with a molten lithium salt, for instance, lithium chloride - potassium chloride eutectic to distribute LiT between the salt and metal phases. The extracted tritium is recovered in gaseous form from the molten salt phase by a subsequent electrolytic or oxidation step.

  5. Asymmetric battery having a semi-solid cathode and high energy density anode

    Energy Technology Data Exchange (ETDEWEB)

    Tan, Taison; Chiang, Yet-Ming; Ota, Naoki; Wilder, Throop; Duduta, Mihai

    2017-11-28

    Embodiments described herein relate generally to devices, systems and methods of producing high energy density batteries having a semi-solid cathode that is thicker than the anode. An electrochemical cell can include a positive electrode current collector, a negative electrode current collector and an ion-permeable membrane disposed between the positive electrode current collector and the negative electrode current collector. The ion-permeable membrane is spaced a first distance from the positive electrode current collector and at least partially defines a positive electroactive zone. The ion-permeable membrane is spaced a second distance from the negative electrode current collector and at least partially defines a negative electroactive zone. The second distance is less than the first distance. A semi-solid cathode that includes a suspension of an active material and a conductive material in a non-aqueous liquid electrolyte is disposed in the positive electroactive zone, and an anode is disposed in the negative electroactive zone.

  6. Semi-Solid and Solid Dosage Forms for the Delivery of Phage Therapy to Epithelia

    Science.gov (United States)

    Petrovski, Steve; Chan, Hiu Tat; Angove, Michael J.; Tucci, Joseph

    2018-01-01

    The delivery of phages to epithelial surfaces for therapeutic outcomes is a realistic proposal, and indeed one which is being currently tested in clinical trials. This paper reviews some of the known research on formulation of phages into semi-solid dosage forms such as creams, ointments and pastes, as well as solid dosage forms such as troches (or lozenges and pastilles) and suppositories/pessaries, for delivery to the epithelia. The efficacy and stability of these phage formulations is discussed, with a focus on selection of optimal semi-solid bases for phage delivery. Issues such as the need for standardisation of techniques for formulation as well as for assessment of efficacy are highlighted. These are important when trying to compare results from a range of experiments and across different delivery bases. PMID:29495355

  7. Applications of a Hybrid Manufacturing Process for Fabrication and Repair of Metallic Structures (Preprint)

    National Research Council Canada - National Science Library

    Liou, Frank; Slattery, Kevin; Kinsella, Mary; Newkirk, Joseph; Chou, Hsin-Nan; Landers, Robert

    2006-01-01

    .... Coupled between the additive and the subtractive processes into a single workstation, the integrated process, or hybrid process, can produce a metal part with machining accuracy and surface finish...

  8. Near net shape processing of zirconium or hafnium metals and alloys

    International Nuclear Information System (INIS)

    Evans, S.C.

    1992-01-01

    This patent describes a process for producing a metal shape. It comprises: plasma arc melting a metal selected from zirconium, hafnium and alloys thereof comprising at least about 90 w/o of these metals to form a liquid pool; pouring the metal form the pool into a mold to form a near net shape; and reducing the metal from its near net shape to a final size while maintaining the metal temperature below the alpha-beta transition temperature throughout the size reducing step

  9. Metal droplet erosion and shielding plasma layer under plasma flows typical of transient processes in tokamaks

    Energy Technology Data Exchange (ETDEWEB)

    Martynenko, Yu. V., E-mail: Martynenko-YV@nrcki.ru [National Research Nuclear University “MEPhI” (Russian Federation)

    2017-03-15

    It is shown that the shielding plasma layer and metal droplet erosion in tokamaks are closely interrelated, because shielding plasma forms from the evaporated metal droplets, while droplet erosion is caused by the shielding plasma flow over the melted metal surface. Analysis of experimental data and theoretical models of these processes is presented.

  10. Semi-solid dosage form of clonazepam for rapid oral mucosal absorption.

    Science.gov (United States)

    Sakata, Osamu; Machida, Yoshiharu; Onishi, Hiraku

    2011-07-01

    In order to obtain an alternative to the intravenous (i.v.) dosage form of clonazepam (CZ), an oral droplet formulation of CZ was developed previously; however, the droplet was physically unstable. Therefore, in the present study, it was attempted to develop an easily-handled dosage form, which was more physically stable and allowed rapid drug absorption from oral mucosa. A semi-solid dosage form, composed of polyethylene glycol 1500 (PEG), CZ, and oleic acid (OA) at 37/1/2 (w/w) and named PEG/CZ/OA, and a semi-solid dosage form containing PEG and CZ at 39/1 (w/w), called PEG/CZ, were prepared. Their physical stability in air at room temperature and oral mucosal absorption in rats were investigated. The semi-solid dosage forms were much more stable physically than the droplet, that is, no recrystallization of CZ was observed for at least 8 days. The effective concentration for humans and rats (20 ng/mL or more) was achieved within 30 min after buccal administration for both PEG/CZ/OA and PEG/CZ. The plasma concentration increased gradually and less varied at each time point for PEG/CZ/OA. PEG/CZ/OA was found to show more rapid and higher absorption of CZ in buccal administration than in sublingual administration. Buccal administration with the semi-solid dosage PEG/CZ with or without OA was suggested to be a possibly useful novel dosage form as an alternative to i.v. injection.

  11. Loss of the ability to generate large burst-forming unit-like megakaryocytic colonies from thawed cord blood in semisolid cultures after short term suspension culture.

    Science.gov (United States)

    Eskola, M; Bäckman, S; Möttönen, S; Kekomäki, R

    2015-04-01

    Total colony-forming cells from thawed cord blood units (CBUs) include megakaryocytic colony-forming units (CFU-Mks), which survive the freezing process. The aim of this study was to evaluate whether different megakaryocytic progenitors from unseparated CBUs survive the freezing process and a short-term liquid culture. Thawed samples of CBUs were cultured in liquid medium. During the cultures, serial samples were drawn to assess the growth of different megakaryocytic progenitors in a semisolid collagen medium with identical cytokines as in the liquid medium. Megakaryocytic cells were detected using immunohistochemistry and flow cytometry. In suspension culture, the megakaryocytic progenitors almost completely lost the ability to generate large (burst-forming unit-like, BFU-like) megakaryocytic colonies in semisolid cultures (large colonies, median count per chamber d0: 7.25 vs. d7: 1.5; P culture in suspension resulted in the decline of small colonies as well (d7: 16.0 vs. d14: 5.75; P = 0.0088). Total CFU-Mk count declined from 23.3 (range 12.5-34.0) at d0 to 7.25 (range 1.0-13.5) at d14 (P culture after a short suspension culture. Small CFU-Mks were observed throughout the cultures. It may be that the BFU-Mk colonies matured and acquired CFU-Mk behaviour. © 2014 International Society of Blood Transfusion.

  12. Process margin enhancement for 0.25-μm metal etch process

    Science.gov (United States)

    Lee, Chung Y.; Ma, Wei Wen; Lim, Eng H.; Cheng, Alex T.; Joy, Raymond; Ross, Matthew F.; Wong, Selmer S.; Marlowe, Trey

    2000-06-01

    This study evaluates electron beam stabilization of UV6, a positive tone Deep-UV (DUV) resist from Shipley, for a 0.25 micrometer metal etch application. Results are compared between untreated resist and resist treated with different levels of electron beam stabilization. The electron beam processing was carried out in an ElectronCureTM flood electron beam exposure system from Honeywell International Inc., Electron Vision. The ElectronCureTM system utilizes a flood electron beam source which is larger in diameter than the substrate being processed, and is capable of variable energy so that the electron range is matched to the resist film thickness. Changes in the UV6 resist material as a result of the electron beam stabilization are monitored via spectroscopic ellipsometry for film thickness and index of refraction changes and FTIR for analysis of chemical changes. Thermal flow stability is evaluated by applying hot plate bakes of 150 degrees Celsius and 200 degrees Celsius, to patterned resist wafers with no treatment and with an electron beam dose level of 2000 (mu) C/cm2. A significant improvement in the thermal flow stability of the patterned UV6 resist features is achieved with the electron beam stabilization process. Etch process performance of the UV6 resist was evaluated by performing a metal pattern transfer process on wafers with untreated resist and comparing these with etch results on wafers with different levels of electron beam stabilization. The etch processing was carried out in an Applied Materials reactor with an etch chemistry including BCl3 and Cl2. All wafers were etched under the same conditions and the resist was treated after etch to prevent further erosion after etch but before SEM analysis. Post metal etch SEM cross-sections show the enhancement in etch resistance provided by the electron beam stabilization process. Enhanced process margin is achieved as a result of the improved etch resistance, and is observed in reduced resist side

  13. INVESTIGATION OF MATERIAL RESISTANCE TO PLASTIC DEFORMATION AT PROCESSING METALS BY PRESSURE WITH IMPOSING ULTRASONIC OSCILLATIONS

    Directory of Open Access Journals (Sweden)

    V. V. Klubovich

    2007-01-01

    Full Text Available The paper contains substantiation for application of experimental technique in order to investigate material resistance to plastic deformation at processing metals by pressure with imposing ultrasonic oscillations while proceeding from laws of similarity. It is shown that at modeling any metal processing by pressure with imposing ultrasonic oscillations it is possible to consider that actual elastic and plastic metal properties remain constant during processing under ultrasound action. The second aspect that requires a special attention at modeling is pulse or vibration-shock deformation at processing metals by pressure with imposing ultrasonic oscillations.

  14. Research of plasma-electrolyte discharge in the processes of obtaining metallic powders

    Science.gov (United States)

    Kashapov, R. N.; Kashapov, L. N.; Kashapov, N. F.

    2017-11-01

    The use of the plasma electrolyte process has never been considered as a simple, cheap and fast method of obtaining powders used in selective laser melting processes. Therefore, the adaptation of the plasma-electrolyte process to the production of metal powders used in additive production is an urgent task. The paper presents the results of studies of gas discharge parameters between a metal and liquid electrode in the processes of obtaining metallic iron powders. The discharge combustion conditions necessary for the formation of metal powders of micron size are determined. A possible mechanism for the formation of powder particles in a discharge plasma is proposed.

  15. Hot-rolled Process of Multilayered Composite Metal Plate

    Directory of Open Access Journals (Sweden)

    YU Wei

    2017-02-01

    Full Text Available For multi-layer plate, it is a difficult problem to increase product yield rate and improve bonding interface quality. A high yield hot-rolled method of multilayered plate was proposed. The raw strips and plate were fixed by argon arc welding. The combined billet was put into a metal box and vacuum pumped, and then heated and rolled by multi passes at the temperature of 1000-1200℃. The 67 layered plate with the thickness of 2.5mm was successfully produced. The interfacial microstructures and diffusion behavior were investigated and analyzed by optical microscopy and scan electronic microscopy. The tensile and shear strength were tested,and the shear fractures were analyzed. The results show that the multilayered plate yield rate is more than 90% by two steps billet combination method and rolling process optimization. The good bonding interface quality is obtained, the shear strength of multilayered plate reaches 241 MPa. Nickel interlayer between 9Cr18 and 1Cr17 can not only prevent the diffusion of carbon, but also improve the microstructure characteristics.

  16. Hydrogen production during processing of radioactive sludge containing noble metals

    International Nuclear Information System (INIS)

    Ha, B.C.; Ferrara, D.M.; Bibler, N.E.

    1992-01-01

    Hydrogen was produced when radioactive sludge from Savannah River Site radioactive waste containing noble metals was reacted with formic acid. This will occur in a process tank in the Defense Waste Facility at SRS when waste is vitrified. Radioactive sludges from four tanks were tested in a lab-scale apparatus. Maximum hydrogen generation rates varied from 5 x10 -7 g H 2 /hr/g of sludge from the least reactive sludge (from Waste Tank 51) to 2 x10 -4 g H 2 /hr/g of sludge from the most reactive sludge (from Waste Tank 11). The time required for the hydrogen generation to reach a maximum varied from 4.1 to 25 hours. In addition to hydrogen, carbon dioxide and nitrous oxide were produced and the pH of the reaction slurry increased. In all cases, the carbon dioxide and nitrous oxide were generated before the hydrogen. The results are in agreement with large-scale studies using simulated sludges

  17. Multiscale processing of loss of metal: a machine learning approach

    Science.gov (United States)

    De Masi, G.; Gentile, M.; Vichi, R.; Bruschi, R.; Gabetta, G.

    2017-07-01

    Corrosion is one of the principal causes of degradation to failure of marine structures. In practice, localized corrosion is the most dangerous mode of attack and can result in serious failures, in particular in marine flowlines and inter-field lines, arousing serious concerns relatively to environmental impact. The progress in time of internal corrosion, the location along the route and across the pipe section, the development pattern and the depth of the loss of metal are a very complex issue: the most important factors are products characteristics, transport conditions over the operating lifespan, process fluid-dynamics, and pipeline geometrical configuration. Understanding which factors among them play the most important role is a key step to develop a model able to predict with enough accuracy the sections more exposed to risk of failure. Some factors play a crucial role at certain spatial scales while other factors at other scales. The Mutual Information Theory, intimately related to the concept of Shannon Entropy in Information theory, has been applied to detect the most important variables at each scale. Finally, the variables emerged from this analysis at each scale have been integrated in a predicting data driven model sensibly improving its performance.

  18. Inverse mathematical modelling and identification in metal powder compaction process

    International Nuclear Information System (INIS)

    Gakwaya, A.; Hrairi, M.; Guillot, M.

    2000-01-01

    An online assessment of the quality of advanced integrated computer aided manufacturing systems require the knowledge of accurate and reliable non-linear constitutive material behavior. This paper is concerned with material parameter identification based on experimental data for which non uniform distribution of stresses and deformation within the volume of the specimen is considered. Both geometric and material non linearities as well interfacial frictional contact are taken into account during the simulation. Within the framework of finite deformation theory, a multisurface multiplicative plasticity model for metal powder compaction process is presented. The model is seen to involve several parameters which are not always activated by a single state variable even though it may be technologically important in assessing the final product quality and manufacturing performance. The resulting expressions are presented in spatial setting and gradient based descent method utilizing the modified Levenberg-Marquardt scheme is used for the minimization of least square functional so as to obtain the best agreement between relevant experimental data and simulated data in a specified energy norm. The identification of a subset of material parameters of the cap model for stainless steel powder compaction is performed. The obtained parameters are validated through a simulation of an industrial part manufacturing case. A very good agreement between simulated final density and measured density is obtained thus demonstrating the practical usefulness of the proposed approach. (author)

  19. Titanium Metal Powder Production by the Plasma Quench Process

    Energy Technology Data Exchange (ETDEWEB)

    R. A. Cordes; A. Donaldson

    2000-09-01

    The goals of this project included the scale-up of the titanium hydride production process to a production rate of 50 kg/hr at a purity level of 99+%. This goal was to be achieved by incrementally increasing the production capability of a series of reactor systems. This methodic approach was designed to allow Idaho Titanium Technologies to systematically address the engineering issues associated with plasma system performance, and powder collection system design and performance. With quality powder available, actual fabrication with the titanium hydride was to be pursued. Finally, with a successful titanium production system in place, the production of titanium aluminide was to be pursued by the simultaneously injection of titanium and aluminum precursors into the reactor system. Some significant accomplishments of the project are: A unique and revolutionary torch/reactor capable of withstanding temperatures up to 5000 C with high thermal efficiency has been operated. The dissociation of titanium tetrachloride into titanium powder and HC1 has been demonstrated, and a one-megawatt reactor potentially capable of producing 100 pounds per hour has been built, but not yet operated at the powder level. The removal of residual subchlorides and adsorbed HC1 and the sintering of powder to form solid bodies have been demonstrated. The production system has been operated at production rates up to 40 pounds per hour. Subsequent to the end of the project, Idaho Titanium Technologies demonstrated that titanium hydride powder can indeed be sintered into solid titanium metal at 1500 C without sintering aids.

  20. Process for continuous production of metallic uranium and uranium alloys

    Science.gov (United States)

    Hayden, Jr., Howard W.; Horton, James A.; Elliott, Guy R. B.

    1995-01-01

    A method is described for forming metallic uranium, or a uranium alloy, from uranium oxide in a manner which substantially eliminates the formation of uranium-containing wastes. A source of uranium dioxide is first provided, for example, by reducing uranium trioxide (UO.sub.3), or any other substantially stable uranium oxide, to form the uranium dioxide (UO.sub.2). This uranium dioxide is then chlorinated to form uranium tetrachloride (UCl.sub.4), and the uranium tetrachloride is then reduced to metallic uranium by reacting the uranium chloride with a metal which will form the chloride of the metal. This last step may be carried out in the presence of another metal capable of forming one or more alloys with metallic uranium to thereby lower the melting point of the reduced uranium product. The metal chloride formed during the uranium tetrachloride reduction step may then be reduced in an electrolysis cell to recover and recycle the metal back to the uranium tetrachloride reduction operation and the chlorine gas back to the uranium dioxide chlorination operation.

  1. Study of heavy metals bioaccumulation in the process of ...

    African Journals Online (AJOL)

    Jane

    2011-07-18

    Jul 18, 2011 ... The bioaccumulation of heavy metals (Cd, Zn, Ni, Pb and Cr) and the relationship between them was investigated on ... this elements in 14 days) exposure, the metal accumulation was measured using atomic absorption spectroscopy. ... sed to the point that it endangers human life in some areas, and the ...

  2. Process for continuous production of metallic uranium and uranium alloys

    Science.gov (United States)

    Hayden, H.W. Jr.; Horton, J.A.; Elliott, G.R.B.

    1995-06-06

    A method is described for forming metallic uranium, or a uranium alloy, from uranium oxide in a manner which substantially eliminates the formation of uranium-containing wastes. A source of uranium dioxide is first provided, for example, by reducing uranium trioxide (UO{sub 3}), or any other substantially stable uranium oxide, to form the uranium dioxide (UO{sub 2}). This uranium dioxide is then chlorinated to form uranium tetrachloride (UCl{sub 4}), and the uranium tetrachloride is then reduced to metallic uranium by reacting the uranium chloride with a metal which will form the chloride of the metal. This last step may be carried out in the presence of another metal capable of forming one or more alloys with metallic uranium to thereby lower the melting point of the reduced uranium product. The metal chloride formed during the uranium tetrachloride reduction step may then be reduced in an electrolysis cell to recover and recycle the metal back to the uranium tetrachloride reduction operation and the chlorine gas back to the uranium dioxide chlorination operation. 4 figs.

  3. Applications of Laser-Induced Breakdown Spectroscopy (LIBS) in Molten Metal Processing

    Science.gov (United States)

    Hudson, Shaymus W.; Craparo, Joseph; De Saro, Robert; Apelian, Diran

    2017-10-01

    In order for metals to meet the demand for critical applications in the automotive, aerospace, and defense industries, tight control over the composition and cleanliness of the metal must be achieved. The use of laser-induced breakdown spectroscopy (LIBS) for applications in metal processing has generated significant interest for its ability to perform quick analyses in situ. The fundamentals of LIBS, current techniques for deployment on molten metal, demonstrated capabilities, and possible avenues for development are reviewed and discussed.

  4. Semi-solid rheocasting of grain refined aluminum alloy 7075

    CSIR Research Space (South Africa)

    Curle, UA

    2010-09-01

    Full Text Available mm×6 mm. Fig.1 shows the whole casting including the runner and the biscuit. A batch of the 7075 alloy was melted in a 20 kg tilting furnace and degassed with argon. A sample was poured and cooled to analyze the starting chemical composition... of the liquid metal by optical emission spectroscopy (Thermo Quantris OES). Thermodynamic properties of the starting alloy were then calculated (Scheil solidification model) with an aluminum thermodynamic database (ProCast 2009.1) using the OES composition...

  5. Process for Making a Noble Metal on Tin Oxide Catalyst

    Science.gov (United States)

    Davis, Patricia; Miller, Irvin; Upchurch, Billy

    2010-01-01

    To produce a noble metal-on-metal oxide catalyst on an inert, high-surface-area support material (that functions as a catalyst at approximately room temperature using chloride-free reagents), for use in a carbon dioxide laser, requires two steps: First, a commercially available, inert, high-surface-area support material (silica spheres) is coated with a thin layer of metal oxide, a monolayer equivalent. Very beneficial results have been obtained using nitric acid as an oxidizing agent because it leaves no residue. It is also helpful if the spheres are first deaerated by boiling in water to allow the entire surface to be coated. A metal, such as tin, is then dissolved in the oxidizing agent/support material mixture to yield, in the case of tin, metastannic acid. Although tin has proven especially beneficial for use in a closed-cycle CO2 laser, in general any metal with two valence states, such as most transition metals and antimony, may be used. The metastannic acid will be adsorbed onto the high-surface-area spheres, coating them. Any excess oxidizing agent is then evaporated, and the resulting metastannic acid-coated spheres are dried and calcined, whereby the metastannic acid becomes tin(IV) oxide. The second step is accomplished by preparing an aqueous mixture of the tin(IV) oxide-coated spheres, and a soluble, chloride-free salt of at least one catalyst metal. The catalyst metal may be selected from the group consisting of platinum, palladium, ruthenium, gold, and rhodium, or other platinum group metals. Extremely beneficial results have been obtained using chloride-free salts of platinum, palladium, or a combination thereof, such as tetraammineplatinum (II) hydroxide ([Pt(NH3)4] (OH)2), or tetraammine palladium nitrate ([Pd(NH3)4](NO3)2).

  6. Improvements in process technology for uranium metal production

    International Nuclear Information System (INIS)

    Meghal, A.M.; Singh, H.; Koppiker, K.S.

    1991-01-01

    The research reactors in Trombay use uranium metal as a fuel. The plant to produce nuclear grade uranium metal ingots has been in operation at Trombay since 1959. Recently, the capacity of the plant has been expanded to meet the additional demand of the uranium metal. The operation of the expanded plant, has brought to the surface various shortcomings. This paper identifies various problems and describes the measures to be taken to upgrade the technology. Some comments are made on the necessity for development of technology for future requirement. (author). 6 refs., 1 fig

  7. Metallization of Extruded Briquettes (BREX in Midrex Process

    Directory of Open Access Journals (Sweden)

    Aitber Bizhanov

    2017-07-01

    Full Text Available The results of the full-scale testing of the Extruded Briquettes (BREX as the charge components of the industrial Midrex reactor are discussed. The influence of the type of binder on the degree of metallization of BREX is analyzed. Magnesium sulfate-based binder helps to reach highest metallization degree of BREX. Mineralogical study shows the difference in the iron-silicate phase’s development as well as in the porosity change during metallization depending on the binder used.

  8. TRANSURANIC METAL HALIDES AND A PROCESS FOR THE PRODUCTION THEREOF

    Science.gov (United States)

    Fried, S.

    1951-03-20

    Halides of transuranic elements are prepared by contacting with aluminum and a halogen, or with an aluminum halide, a transuranic metal oxide, oxyhalide, halide, or mixture thereof at an elevated temperature.

  9. Coagulation / flocculation process in the removal of trace metals ...

    African Journals Online (AJOL)

    DR. MIKE HORSFALL

    elements such as Cu, Zn, Ni and Cr, as well as ... solids, (2) separation of suspended solids by chemical ... Total Metal Concentration Of The Wastewater: The .... Copper adsorption by esterifies and unesterified fractions of sphagnum peat ...

  10. Metals recovery of spent household batteries using a hydrometallurgical process

    International Nuclear Information System (INIS)

    Souza, K.P.; Tenorio, J.A.S.

    2010-01-01

    The objective of the work is to study a method for metals recovery from a sample composed by a mixture of the main types of spent household batteries. Segregation of the main metals is investigated using a treatment route consisting of the following steps: manual identified and dismantling, grinding, electric furnace reduction, acid leaching and selective precipitation with sodium hydroxide with and without hydrogen peroxide. Before and after precipitations the solutions had been analyzed by Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP/OES) and the precipitated analyzed by Scanning Electron Microscopy (SEM) with Spectrometry of Energy Dispersion Spectroscopy (EDS). The results had indicated that the great majority of metals had been precipitated in pHs studied, also had co-precipitation or simultaneous precipitation of metals in some pHs. (author)

  11. Anticancer Activity of Metal Complexes: Involvement of Redox Processes

    Science.gov (United States)

    Jungwirth, Ute; Kowol, Christian R.; Keppler, Bernhard K.; Hartinger, Christian G.; Berger, Walter; Heffeter, Petra

    2012-01-01

    Cells require tight regulation of the intracellular redox balance and consequently of reactive oxygen species for proper redox signaling and maintenance of metal (e.g., of iron and copper) homeostasis. In several diseases, including cancer, this balance is disturbed. Therefore, anticancer drugs targeting the redox systems, for example, glutathione and thioredoxin, have entered focus of interest. Anticancer metal complexes (platinum, gold, arsenic, ruthenium, rhodium, copper, vanadium, cobalt, manganese, gadolinium, and molybdenum) have been shown to strongly interact with or even disturb cellular redox homeostasis. In this context, especially the hypothesis of “activation by reduction” as well as the “hard and soft acids and bases” theory with respect to coordination of metal ions to cellular ligands represent important concepts to understand the molecular modes of action of anticancer metal drugs. The aim of this review is to highlight specific interactions of metal-based anticancer drugs with the cellular redox homeostasis and to explain this behavior by considering chemical properties of the respective anticancer metal complexes currently either in (pre)clinical development or in daily clinical routine in oncology. PMID:21275772

  12. INTEGRATED BIOREACTOR SYSTEM FOR THE TREATMENT OF CYANIDE, METALS AND NITRATES IN MINE PROCESS WATER

    Science.gov (United States)

    An innovative biological process is described for the tratment of cyanide-, metals- and nitrate-contaminated mine process water. The technology was tested for its ability to detoxify cyanide and nitrate and to immobilize metals in wastewater from agitation cyanide leaching. A pil...

  13. Uptake of heavy metals by Typha capensis from wetland sites polluted by effluent from mineral processing plants: implications of metal-metal interactions.

    Science.gov (United States)

    Zaranyika, M F; Nyati, W

    2017-10-01

    The aim of the present work was to demonstrate the existence of metal-metal interactions in plants and their implications for the absorption of toxic elements like Cr. Typha capensis , a good accumulator of heavy metals, was chosen for the study. Levels of Fe, Cr, Ni, Cd, Pb, Cu and Zn were determined in the soil and roots, rhizomes, stems and leaves of T. capensis from three Sites A, B and C polluted by effluent from a chrome ore processing plant, a gold ore processing plant, and a nickel ore processing plant, respectively. The levels of Cr were extremely high at Site A at 5415 and 786-16,047 μg g -1 dry weight in the soil and the plant, respectively, while the levels of Ni were high at Site C at 176 and 24-891 μg g -1 in the soil and the plant, respectively. The levels of Fe were high at all three sites at 2502-7500 and 906-13,833 μg g -1 in the soil and plant, respectively. For the rest of the metals, levels were modest at 8.5-148 and 2-264 μg g -1 in the soil and plant, respectively. Pearson's correlation analysis confirmed mutual synergistic metal-metal interactions in the uptake of Zn, Cu, Co, Ni, Fe, and Cr, which are attributed to the similarity in the radii and coordination geometry of the cations of these elements. The implications of such metal-metal interactions (or effects of one metal on the behaviour of another) on the uptake of Cr, a toxic element, and possible Cr detoxification mechanism within the plant, are discussed.

  14. Effect of a Semisolid Formulation of Linum usitatissimum L. (Linseed Oil on the Repair of Skin Wounds

    Directory of Open Access Journals (Sweden)

    Eryvelton de Souza Franco

    2012-01-01

    Full Text Available The purpose of this study was to investigate the effects of a semisolid formulation of linseed oil, SSFLO (1%, 5%, or 10% or in natura linseed oil on skin wounds of rats. We used wound models, incisional and excisional, to evaluate, respectively, the contraction/reepithelialization of the wound and resistance to mechanical traction. The groups (n=6 treated with SSFLO (1% or 5% began the process of reepithelialization, to a significant extent (P<.05, on the sixth day, when compared to the petroleum jelly control group. On 14th day for the groups treated with SSFLO (1% or 5%, 100% reepithelialization was found, while in the petroleum jelly control group, this was only 33.33%. Our study showed that topical administration of SSFLO (1% or 5% in excisional wounds allowed reepithelialization in 100% of treated animals. Therefore, a therapeutic potential of linseed oil, when used at low concentrations in the solid pharmaceutical formulations, is suggested for the process of dermal repair.

  15. Containerless Heating Process of a Deeply Undercooled Metal Droplet by Electrostatic Levitation

    International Nuclear Information System (INIS)

    Wang Fei-Long; Dai Bin; Liu Xue-Feng; Sun Yi-Ning; Sun Zhi-Bin; Yu Qiang; Zhai Guang-Jie

    2015-01-01

    We present the containerless heating process of a deeply undercooled metal droplet by electrostatic levitation. The problem of surface charge loss in the heating process is discussed and specific formulas are given to describe the basic process of charge supplement by the photoelectric and thermoelectric effects. The pure metal zirconium is used to be melted and solidified to analyze the heating process. The temperature-time curve clearly shows the features including melting, undercooling, recalescence and solid-state phase transformation. (paper)

  16. Numerical Modeling of Fiber-Reinforced Metal Matrix Composite Processing by the Liquid Route: Literature Contribution

    Science.gov (United States)

    Lacoste, Eric; Arvieu, Corinne; Mantaux, Olivier

    2018-04-01

    One of the technologies used to produce metal matrix composites (MMCs) is liquid route processing. One solution is to inject a liquid metal under pressure or at constant rate through a fibrous preform. This foundry technique overcomes the problem of the wettability of ceramic fibers by liquid metal. The liquid route can also be used to produce semiproducts by coating a filament with a molten metal. These processes involve physical phenomena combined with mass and heat transfer and phase change. The phase change phenomena related to solidification and also to the melting of the metal during the process notably result in modifications to the permeability of porous media, in gaps in impregnation, in the appearance of defects (porosities), and in segregation in the final product. In this article, we provide a state-of-the-art review of numerical models and simulation developed to study these physical phenomena involved in MMC processing by the liquid route.

  17. Process development study on production of uranium metal from monazite sourced crude uranium tetra-fluoride

    International Nuclear Information System (INIS)

    Chowdhury, S; Satpati, S.K.; Hareendran, K.N.; Roy, S.B.

    2014-01-01

    Development of an economic process for recovery, process flow sheet development, purification and further conversion to nuclear grade uranium metal from the crude UF 4 has been a technological challenge and the present paper, discusses the same.The developed flow-sheet is a combination of hydrometallurgical and pyrometallurgical processes. Crude UF 4 is converted to uranium di-oxide (UO 2 ) by chemical conversion route and UO 2 produced is made fluoride-free by repeated repulping, followed by solid liquid separation. Uranium di-oxide is then purified by two stages of dissolution and suitable solvent extraction methods to get uranium nitrate pure solution (UNPS). UNPS is then precipitated with air diluted ammonia in a leak tight stirred vessel under controlled operational conditions to obtain ammonium di-uranate (ADU). The ADU is then calcined and reduced to produce metal grade UO 2 followed by hydro-fluorination using anhydrous hydrofluoric acid to obtain metal grade UF 4 with ammonium oxalate insoluble (AOI) content of 4 is essential for critical upstream conversion process. Nuclear grade uranium metal ingot is finally produced by metallothermic reduction process at 650℃ in a closed vessel, called bomb reactor. In the process, metal-slag separation plays an important role for attaining metal purity as well as process yield. Technological as well economic feasibility of indigenously developed process for large scale production of uranium metal from the crude UF 4 has been established in Bhabha Atomic Research Centre (BARC), India

  18. Powder metallurgical processing and metal purity: A case for ...

    Indian Academy of Sciences (India)

    Unknown

    The paper reviews the role of sintered tantalum as volumetric efficient electrical capacitor. Powder characteristics ... Tantalum is used mainly as a corrosion resistant metal in the chemical industries, as high temperature heating elements and in .... materials cleaning and careful control of plant cleanliness. Table 1. Impurity ...

  19. Trace metals transfer during vine cultivation and winemaking processes

    Czech Academy of Sciences Publication Activity Database

    Vystavna, Yuliya; Zaichenko, L.; Klimenko, N.; Rätsep, R.

    2017-01-01

    Roč. 97, č. 13 (2017), s. 4520-4525 ISSN 0022-5142 Institutional support: RVO:60077344 Keywords : white wine * Chardonnay * Vitis * Ukraine * vineyard * trace metals Subject RIV: DJ - Water Pollution ; Quality OBOR OECD: Environmental sciences (social aspects to be 5.7) Impact factor: 2.463, year: 2016

  20. Microstructure Development and Characteristics of Semisolid Aluminum Alloys; FINAL

    International Nuclear Information System (INIS)

    Merton Flemings; Srinath Viswanathan

    2001-01-01

    A drop forge viscometer was employed to investigate the flow behavior under very rapid compression rates of A357, A356 diluted with pure aluminum and Al-4.5%Cu alloys. The A357 alloys were of commercial origin (MHD and SIMA) and the rheocast, modified A356 and Al-4.5Cu alloys were produced by a process developed at the solidification laboratory of MIT

  1. Process for the recovery of alkali metal salts from aqueous solutions thereof

    International Nuclear Information System (INIS)

    Vitner, J.

    1984-01-01

    In an integrated process for the recovery of alkakli metal phenates and carboxylates from aqueous solutions thereof, the aqueous solution is spray dried and the drying gas stream is contacted with an aqueous alkali metal salt solution which dissolves the particles of the alkali metal salt that were entrained in the drying gas stream. The salt-free inert gas stream is then dried, heated, and returned to the spray dryer

  2. Physical removal of metallic carbon nanotubes from nanotube network devices using a thermal and fluidic process

    International Nuclear Information System (INIS)

    Ford, Alexandra C; Shaughnessy, Michael; Wong, Bryan M; Kane, Alexander A; Krafcik, Karen L; Léonard, François; Kuznetsov, Oleksandr V; Billups, W Edward; Hauge, Robert H

    2013-01-01

    Electronic and optoelectronic devices based on thin films of carbon nanotubes are currently limited by the presence of metallic nanotubes. Here we present a novel approach based on nanotube alkyl functionalization to physically remove the metallic nanotubes from such network devices. The process relies on preferential thermal desorption of the alkyls from the semiconducting nanotubes and the subsequent dissolution and selective removal of the metallic nanotubes in chloroform. The approach is versatile and is applied to devices post-fabrication. (paper)

  3. Development Trends And Economic Assessment Of The Integration Processes On The Metals Market

    OpenAIRE

    Romanova, Olga A.; Makarov, Eduard V.

    2018-01-01

    The article examines the integration process from the perspective of three dimensions, which characterize the increase in quantity and appearance of new relationships; strength, character and stability of emerging communications; dynamics and the proper form of the process. The authors identify the development trends of the integration processes in the metals market and provide justification for the breaking of the period of Russian metal trading for 1991–2016 into five stages of development....

  4. Evaluating the Metal Tolerance Capacity of Microbial Communities Isolated from Alberta Oil Sands Process Water.

    Directory of Open Access Journals (Sweden)

    Mathew L Frankel

    Full Text Available Anthropogenic activities have resulted in the intensified use of water resources. For example, open pit bitumen extraction by Canada's oil sands operations uses an estimated volume of three barrels of water for every barrel of oil produced. The waste tailings-oil sands process water (OSPW-are stored in holding ponds, and present an environmental concern as they are comprised of residual hydrocarbons and metals. Following the hypothesis that endogenous OSPW microbial communities have an enhanced tolerance to heavy metals, we tested the capacity of planktonic and biofilm populations from OSPW to withstand metal ion challenges, using Cupriavidus metallidurans, a known metal-resistant organism, for comparison. The toxicity of the metals toward biofilm and planktonic bacterial populations was determined by measuring the minimum biofilm inhibitory concentrations (MBICs and planktonic minimum inhibitory concentrations (MICs using the MBEC ™ assay. We observed that the OSPW community and C. metallidurans had similar tolerances to 22 different metals. While thiophillic elements (Te, Ag, Cd, Ni were found to be most toxic, the OSPW consortia demonstrated higher tolerance to metals reported in tailings ponds (Al, Fe, Mo, Pb. Metal toxicity correlated with a number of physicochemical characteristics of the metals. Parameters reflecting metal-ligand affinities showed fewer and weaker correlations for the community compared to C. metallidurans, suggesting that the OSPW consortia may have developed tolerance mechanisms toward metals present in their environment.

  5. Semisolid matrix-filled hard gelatin capsules for rapid dissolution of amlodipine besilate: Development and assessment

    Directory of Open Access Journals (Sweden)

    Vijay K Tyagi

    2013-01-01

    Full Text Available The objective of the study was to prepare semisolid capsules (SSCs of poorly water-soluble drug amlodipine besilate (AB using a combination of technologies involving solid dispersion (SD preparation and converting it into semisolid matrix filled in hard gelatin capsules (termed as SSCs with the aim of reducing lag time in drug release and to improve the dissolution rate. AB is used for its anti-arrhythmic, anti-anginal, and anti-hypertensive activity. These are the emergency activities which should be treated as fast as possible like in the case of angina attack (heart attack. Any lag time that is generated due to its poor dissolution can add on in this emergency and that can be avoided by developing a readily dissolvable formulation: SDs of AB. SD of AB was prepared by fusion method using varying combinations of Poloxamer 407 and Plasdone S630. A total of nine batches (SD1−SD9 were characterized for the in vitro dissolution behavior in phosphate buffer pH7.4. SD8 with 95.8% cumulative drug release in 60 min, t50% = 4.1 min and DE 30 Min = 84.2% were selected for the development of the semisolid matrix. Differential scanning calorimetry of SD8 revealed molecular dispersion of AB and Plasdone S630 in Poloxamer 407. SD8 was then formulated as SSCs using gelucire 44/14 and PEG 400 as semisolid components and PEG 6000 as a suspending agent to achieve the reduction in lag time for drug release. A total of seven SSC formulations were prepared and evaluated for drug release. Formulation of SSC4 showed maximum cumulative drug release (CDR of 98.9% within 20 min that was almost a threefold reduction in the time required to achieve similar CDR by SD of AB. Thus, SSCs present an excellent approach to enhance the dissolution as well as to reduce the lag time of dissolution for poor water-soluble drugs especially to those therapeutic classes that are intended for faster onset of action.

  6. Optimisation de la fermentation en milieu semi-solide pour la ...

    African Journals Online (AJOL)

    Objectif : Evaluer trois équipements pour la fermentation de la pâte destinée à préparer l'ablo (pâte cuite à la vapeur) puis, l'influence de la température, de la durée de fermentation et du taux de levure ajoutée à la pâte. Méthodologie et résultats : La pâte semi-solide a été fermentée durant quatre heures à température ...

  7. Comparative evaluation of microbial and chemical leaching processes for heavy metal removal from dewatered metal plating sludge

    International Nuclear Information System (INIS)

    Bayat, Belgin; Sari, Bulent

    2010-01-01

    The purpose of the study described in this paper was to evaluate the application of bioleaching technique involving Acidithiobacillus ferrooxidans to recover heavy metals (Zn, Cu, Ni, Pb, Cd and Cr) in dewatered metal plating sludge (with no sulfide or sulfate compounds). The effect of some conditional parameters (i.e. pH, oxidation-reduction potential (ORP), sulfate production) and operational parameters (i.e. pulp density of the sludge and agitation time) were investigated in a 3 l completely mixed batch (CMB) reactor. The metal recovery yields in bioleaching were also compared with chemical leaching of the sludge waste using commercial inorganic acids (sulfuric acids and ferric chloride). The leaching of heavy metals increased with decreasing of pH and increasing of ORP and sulfate production during the bioleaching experiment. Optimum pulp density for bioleaching was observed at 2% (w/v), and leaching efficiency decreased with increasing pulp density in bioleaching experiments. Maximum metal solubilization (97% of Zn, 96% of Cu, 93% of Ni, 84% of Pb, 67% of Cd and 34% of Cr) was achieved at pH 2, solids contents of 2% (w/v), and a reaction temperature of 25 ± 2 deg. C during the bioleaching process. The maximum removal efficiencies of 72% and 79% Zn, 70% and 75% Cu, 69% and 73% Ni, 57% and 70% Pb, 55% and 65% Cd, and 11% and 22% Cr were also attained with the chemical leaching using sulfuric acids and ferric chloride, respectively, at pH 2, solids contents of 2% (w/v), and a reaction temperature of 25 ± 2 deg. C during the acid leaching processes. The rates of metal leaching for bioleaching and chemical leaching are well described by a kinetic equation related to time. Although bioleaching generally requires a longer period of operation compared to chemical leaching, it achieves higher removal efficiency for heavy metals. The efficiency of leaching processes can be arranged in descending order as follows: bioleaching > ferric chloride leaching > sulfuric acid

  8. Comparative evaluation of microbial and chemical leaching processes for heavy metal removal from dewatered metal plating sludge

    Energy Technology Data Exchange (ETDEWEB)

    Bayat, Belgin, E-mail: bbayat@cu.edu.tr [Department of Environmental Engineering, Faculty of Engineering and Architecture, Cukurova University, Balcali, Adana 01330 (Turkey); Sari, Bulent [Department of Environmental Engineering, Faculty of Engineering and Architecture, Cukurova University, Balcali, Adana 01330 (Turkey)

    2010-02-15

    The purpose of the study described in this paper was to evaluate the application of bioleaching technique involving Acidithiobacillus ferrooxidans to recover heavy metals (Zn, Cu, Ni, Pb, Cd and Cr) in dewatered metal plating sludge (with no sulfide or sulfate compounds). The effect of some conditional parameters (i.e. pH, oxidation-reduction potential (ORP), sulfate production) and operational parameters (i.e. pulp density of the sludge and agitation time) were investigated in a 3 l completely mixed batch (CMB) reactor. The metal recovery yields in bioleaching were also compared with chemical leaching of the sludge waste using commercial inorganic acids (sulfuric acids and ferric chloride). The leaching of heavy metals increased with decreasing of pH and increasing of ORP and sulfate production during the bioleaching experiment. Optimum pulp density for bioleaching was observed at 2% (w/v), and leaching efficiency decreased with increasing pulp density in bioleaching experiments. Maximum metal solubilization (97% of Zn, 96% of Cu, 93% of Ni, 84% of Pb, 67% of Cd and 34% of Cr) was achieved at pH 2, solids contents of 2% (w/v), and a reaction temperature of 25 {+-} 2 deg. C during the bioleaching process. The maximum removal efficiencies of 72% and 79% Zn, 70% and 75% Cu, 69% and 73% Ni, 57% and 70% Pb, 55% and 65% Cd, and 11% and 22% Cr were also attained with the chemical leaching using sulfuric acids and ferric chloride, respectively, at pH 2, solids contents of 2% (w/v), and a reaction temperature of 25 {+-} 2 deg. C during the acid leaching processes. The rates of metal leaching for bioleaching and chemical leaching are well described by a kinetic equation related to time. Although bioleaching generally requires a longer period of operation compared to chemical leaching, it achieves higher removal efficiency for heavy metals. The efficiency of leaching processes can be arranged in descending order as follows: bioleaching > ferric chloride leaching > sulfuric

  9. Toxic metals in WEEE: Characterization and substance flow analysis in waste treatment processes

    Energy Technology Data Exchange (ETDEWEB)

    Oguchi, Masahiro, E-mail: oguchi.masahiro@nies.go.jp; Sakanakura, Hirofumi; Terazono, Atsushi

    2013-10-01

    Waste electrical and electronic equipment (WEEE) has received extensive attention as a secondary source of metals. Because WEEE also contains toxic substances such as heavy metals, appropriate management of these substances is important in the recycling and treatment of WEEE. As a basis for discussion toward better management of WEEE, this study characterizes various types of WEEE in terms of toxic metal contents. The fate of various metals contained in WEEE, including toxic metals, was also investigated in actual waste treatment processes. Cathode-ray tube televisions showed the highest concentration and the largest total amount of toxic metals such as Ba, Pb, and Sb, so appropriate recycling and disposal of these televisions would greatly contribute to better management of toxic metals in WEEE. A future challenge is the management of toxic metals in mid-sized items such as audio/visual and ICT equipment because even though the concentrations were not high in these items, the total amount of toxic metals contained in them is not negligible. In the case of Japan, such mid-sized WEEE items as well as small electronic items are subject to municipal solid waste treatment. A case study showed that a landfill was the main destination of toxic metals contained in those items in the current treatment systems. The case study also showed that changes in the flows of toxic metals will occur when treatment processes are modified to emphasize resource recovery. Because the flow changes might lead to an increase in the amount of toxic metals released to the environment, the flows of toxic metals and the materials targeted for resource recovery should be considered simultaneously. - Highlights: ► Appropriate management of toxic metals contained in WEEE is important during recycling and treatment of WEEE. ► CRT TVs contain large amount of toxic metals with high concentration and thus appropriate management is highly important. ► Mid-sized equipment is a future target for

  10. Wear of semi-solid rheocast SiCp/Al metal matrix composites

    CSIR Research Space (South Africa)

    Curle, UA

    2010-09-01

    Full Text Available ). Hardness increases as the volume fractions of SiC increases. Wear rates of the MMCs in the F and T6 heat treatment conditions were assessed with a metallographic preparation machine. It is found that the 11% SiC MMC wear rate is higher on SiC abrasives...

  11. Metal Halide Perovskite Single Crystals: From Growth Process to Application

    Directory of Open Access Journals (Sweden)

    Shuigen Li

    2018-05-01

    Full Text Available As a strong competitor in the field of optoelectronic applications, organic-inorganic metal hybrid perovskites have been paid much attention because of their superior characteristics, which include broad absorption from visible to near-infrared region, tunable optical and electronic properties, high charge mobility, long exciton diffusion length and carrier recombination lifetime, etc. It is noted that perovskite single crystals show remarkably low trap-state densities and long carrier diffusion lengths, which are even comparable with the best photovoltaic-quality silicon, and thus are expected to provide better optoelectronic performance. This paper reviews the recent development of crystal growth in single-, mixed-organic-cation and fully inorganic halide perovskite single crystals, in particular the solution approach. Furthermore, the application of metal hybrid perovskite single crystals and future perspectives are also highlighted.

  12. Physical masking process for integrating micro metallic structures on polymer substrate

    DEFF Research Database (Denmark)

    Islam, Mohammad Aminul; Hansen, Hans Nørgaard

    2009-01-01

    plasmon devices need micro metallic structures on a polymer substrate with an uniform metal layer thickness in the nanometer range. A well known fabrication process to achieve such metallic surface pattern on polymer substrate is photolithography which involves an expensive mask and toxic chemicals......Integration of micro metallic structures in polymer devices is a broad multi-disciplinary research field, consisting of various combinations of mechanical, chemical and physical fabrication methods. Each of the methods has its specific advantages and disadvantages. Some applications like surface....... The current study shows a novel approach for fabricating thin micro metallic structures on polymer substrates using a simple physical mask and a PVD equipment. The new process involves fewer process steps, it is cost effective and suitable for high volume industrial production. Current study suggests...

  13. Heavy metal evaporation kinetics in thermal waste treatment processes

    Energy Technology Data Exchange (ETDEWEB)

    Ludwig, Ch; Stucki, S; Schuler, A J [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1999-08-01

    To investigate the evaporation kinetics of heavy metals, experiments were performed by conventional thermogravimetry and a new method using Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES). The new method allows online measurements in time intervals that are typically below one minute. The evaporation of Cd, Cu, Pb, and Zn from synthetic mixtures and filter ashes from municipal solid waste incineration (MSWI) was of major interest. (author) 2 figs., 4 refs.

  14. New antipollution processing of a used refining catalyst and complete recovery of the catalyst metallic components

    Energy Technology Data Exchange (ETDEWEB)

    Trinh Dinh Chan; Llido, E.

    1992-05-15

    The used refining catalyst, containing metals such as vanadium, nickel and iron, is first processed by stripping; it is then calcined in critical conditions and heat processed in the presence of a melted alkaline base; the resulting solid matter is then water processed. The antipollution process can be applied to oil fraction hydroconversion or hydroprocessing catalysts.

  15. A case in support of implementing innovative bio-processes in the metal mining industry

    NARCIS (Netherlands)

    Sanchez Andrea, I.; Stams, A.J.M.; Weijma, J.; Gonzalez Contreras, P.A.; Dijkman, H.; Rozendal, R.A.; Johnson, D.B.

    2016-01-01

    The metal mining industry faces many large challenges in future years, among which is the increasing need to process low-grade ores as accessible higher grade ores become depleted. This is against a backdrop of increasing global demands for base and precious metals, and rare earth elements.

  16. Fused salt processing of impure plutonium dioxide to high-purity plutonium metal

    International Nuclear Information System (INIS)

    Mullins, L.J.; Christensen, D.C.; Babcock, B.R.

    1982-01-01

    A process for converting impure plutonium dioxide (approx. 96% pure) to high-purity plutonium metal (>99.9%) was developed. The process consists of reducing the oxide to an impure plutonium metal intermediate with calcium metal in molten calcium chloride. The impure intermediate metal is cast into an anode and electrorefined to produce high-purity plutonium metal. The oxide reduction step is being done now on a 0.6-kg scale with the resulting yield being >99.5%. The electrorefining is being done on a 4.0-kg scale with the resulting yield being 80 to 85%. The purity of the product, which averages 99.98%, is essentially insensitive to the purity of the feed metal. The yield, however, is directly dependent on the chemical composition of the feed. To date, approximately 250 kg of impure oxide has been converted to pure metal by this processing sequence. The availability of impure plutonium dioxide, together with the need for pure plutonium metal, makes this sequence a valuable plutonium processing tool

  17. Forming processes and mechanics of sheet metal forming

    NARCIS (Netherlands)

    Burchitz, I.A.

    2004-01-01

    The report is dealing with the numerical analysis of forming processes. Forming processes is the large group of manufacturing processes used to obtain various product shapes by means of plastic deformations. The report is organized as follows. An overview of the deformation processes and the

  18. Composites Strengthened with Graphene Platelets and Formed in Semisolid State Based on α and α/β MgLiAl Alloys

    Science.gov (United States)

    Dutkiewicz, Jan; Rogal, Łukasz; Fima, Przemyslaw; Ozga, Piotr

    2018-05-01

    MgLiAl base composites strengthened with graphene platelets were prepared by semisolid processing of ball-milled alloy chips with 2% of graphene platelets. Composites strengthened with graphene platelets show higher hardness and yield stress than the cast alloys, i.e., 160 MPa as compared to 90 MPa for as-cast alloy MgLi9Al1.5. Mechanical properties for MgLiAl-based composites were similar or higher than for composites based on conventional AZ91 or WE43 alloys. The strengthening however was not only due to the presence of graphene, but also phases resulting from the reaction between carbon and lithium, i.e., Li2C2 carbide. Graphene platelets were located at globules boundaries resulting from semisolid processing for all investigated composites. Graphene platelets were in agglomerates forming continuous layers at grain boundaries in the composite based on the alloy MgLi4.5Al1.5. The shape of agglomerates was more complex and wavy in the composite based on MgLi9Al1.5 alloy most probably due to lithium-graphene reaction. Electron diffraction from the two-phase region α + β in MgLi9Al1.5 indicated that [001]α and [110]β directions are rotated about 4° from the ideal relationship [001] hex || [110] bcc phases. It showed higher lattice rotation than in earlier studies what is most probably caused by lattice slip and rotation during semisolid pressing causing substantial deformation particularly within the β phase. Raman spectroscopy studies confirmed the presence of graphene platelets within agglomerates and in addition the presence mainly of Li2C2 carbides in composites based on MgLi4.5Al1.5 and Mg9Li1.5Al alloys. From the character of Raman spectra refinement of graphene platelets was found in comparison with their initial size. The graphene areas without carbides contain graphene nanoplatelets with lateral dimension close to initial graphene sample. Electron diffraction allowed to confirm the presence of Li2C2 carbide at the surface of agglomerates found from

  19. Numerical simulation of the alloying process during impulse induction heating of the metal substrate

    Science.gov (United States)

    Popov, V. N.

    2017-10-01

    2D numerical modeling of the processes during the alloying of the substrate surface metal layer is carried out. Heating, phase transition, heat and mass transfer in the molten metal, solidification of the melt are considered with the aid the proposed mathematical model. Under study is the applicability of the high-frequency electromagnetic field impulse for metal heating and melting. The distribution of the electromagnetic energy in the metal is described by empirical formulas. According to the results of numerical experiments, the flow structure in the melt and distribution of the alloying substances is evaluated.

  20. Bio-processing of solid wastes and secondary resources for metal extraction – A review

    International Nuclear Information System (INIS)

    Lee, Jae-chun; Pandey, Banshi Dhar

    2012-01-01

    Highlights: ► Review focuses on bio-extraction of metals from solid wastes of industries and consumer goods. ► Bio-processing of certain effluents/wastewaters with metals is also included in brief. ► Quantity/composition of wastes are assessed, and microbes used and leaching conditions included. ► Bio-recovery using bacteria, fungi and archaea is highlighted for resource recycling. ► Process methodology/mechanism, R and D direction and scope of large scale use are briefly included. - Abstract: Metal containing wastes/byproducts of various industries, used consumer goods, and municipal waste are potential pollutants, if not treated properly. They may also be important secondary resources if processed in eco-friendly manner for secured supply of contained metals/materials. Bio-extraction of metals from such resources with microbes such as bacteria, fungi and archaea is being increasingly explored to meet the twin objectives of resource recycling and pollution mitigation. This review focuses on the bio-processing of solid wastes/byproducts of metallurgical and manufacturing industries, chemical/petrochemical plants, electroplating and tanning units, besides sewage sludge and fly ash of municipal incinerators, electronic wastes (e-wastes/PCBs), used batteries, etc. An assessment has been made to quantify the wastes generated and its compositions, microbes used, metal leaching efficiency etc. Processing of certain effluents and wastewaters comprising of metals is also included in brief. Future directions of research are highlighted.

  1. New catalysts for coal processing: Metal carbides and nitrides

    Energy Technology Data Exchange (ETDEWEB)

    S. Ted Oyama; David F. Cox

    1999-12-03

    The subject of this research project was to investigate the catalytic properties of a new class of materials, transition metal carbides and nitrides, for treatment of coal liquid and petroleum feedstocks. The main objectives were: (1) preparation of catalysts in unsupported and supported form; (2) characterization of the materials; (3) evaluation of their catalytic properties in HDS and HDN; (4) measurement of the surface properties; and (5) observation of adsorbed species. All of the objectives were substantially carried out and the results will be described in detail below. The catalysts were transition metal carbides and nitrides spanning Groups 4--6 in the Periodic Table. They were chosen for study because initial work had shown they were promising materials for hydrotreating. The basic strategy was first to prepare the materials in unsupported form to identify the most promising catalyst, and then to synthesize a supported form of the material. Already work had been carried out on the synthesis of the Group VI compounds Mo{sub 2}C, Mo{sub 2}N, and WC, and new methods were developed for the Group V compounds VC and NbC. All the catalysts were then evaluated in a hydrotreating test at realistic conditions. It was found that the most active catalyst was Mo{sub 2}C, and further investigations of the material were carried out in supported form. A new technique was employed for the study of the bulk and surface properties of the catalysts, near edge x-ray absorption spectroscopy (NEXAFS), that fingerprinted the electronic structure of the materials. Finally, two new research direction were explored. Bimetallic alloys formed between two transition metals were prepared, resulting in catalysts having even higher activity than Mo{sub 2}C. The performance of the catalysts in hydrodechloration was also investigated.

  2. Unusual presentation of failed metal-on-metal total hip arthroplasty with features of neoplastic process

    Directory of Open Access Journals (Sweden)

    Robert P. Runner, MD

    2017-06-01

    Full Text Available Metal-on-metal (MoM total hip arthroplasty (THA is associated with increased incidence of failure from metallosis, adverse tissue reactions, and the formation of pseudotumors. This case highlights a 53-year-old female with an enlarging painful thigh mass 12 years status post MoM THA. Radiographs and advanced imaging revealed an atypical mass with cortical bone destruction and spiculation, concerning for periprosthetic malignancy. Open frozen section biopsy was performed before undergoing revision THA in a single episode of care. This case illustrates that massive pseudotumors can be locally aggressive causing significant femoral bone destruction and may mimic malignancy. It is important that orthopaedic surgeons, radiologists and pathologists understand the relative infrequency of periprosthetic malignancy in MoM THA to mitigate patient concerns, misdiagnosis, and allow for an evidence based discussion when treating massive pseudotumors.

  3. Process for electrolytic deposition of metals on zirconium materials

    International Nuclear Information System (INIS)

    Donaghy, R.E.

    1981-01-01

    An article made of a zirconium alloy can be electrolytically plated with a layer of a metal such as copper, nickel or chromium when the article is free of any loosely adhering film formed during an activation step. The article is activated in an aged aqueous solution of ammonium bifluoride and sulfuric acid. Next the loosely adhering film formed in the first step is removed by chemical treatment, ultrasonic cleaning, or by swabbing the surface with cotton or an organic material. Finally the article is contacted with an electrolytic plating solution in the presence of an electrode receiving current

  4. Probabilistic Design in a Sheet Metal Stamping Process under Failure Analysis

    International Nuclear Information System (INIS)

    Buranathiti, Thaweepat; Cao, Jian; Chen, Wei; Xia, Z. Cedric

    2005-01-01

    Sheet metal stamping processes have been widely implemented in many industries due to its repeatability and productivity. In general, the simulations for a sheet metal forming process involve nonlinearity, complex material behavior and tool-material interaction. Instabilities in terms of tearing and wrinkling are major concerns in many sheet metal stamping processes. In this work, a sheet metal stamping process of a mild steel for a wheelhouse used in automobile industry is studied by using an explicit nonlinear finite element code and incorporating failure analysis (tearing and wrinkling) and design under uncertainty. Margins of tearing and wrinkling are quantitatively defined via stress-based criteria for system-level design. The forming process utilizes drawbeads instead of using the blank holder force to restrain the blank. The main parameters of interest in this work are friction conditions, drawbead configurations, sheet metal properties, and numerical errors. A robust design model is created to conduct a probabilistic design, which is made possible for this complex engineering process via an efficient uncertainty propagation technique. The method called the weighted three-point-based method estimates the statistical characteristics (mean and variance) of the responses of interest (margins of failures), and provide a systematic approach in designing a sheet metal forming process under the framework of design under uncertainty

  5. Discussion of Carbon Emissions for Charging Hot Metal in EAF Steelmaking Process

    Science.gov (United States)

    Yang, Ling-zhi; Jiang, Tao; Li, Guang-hui; Guo, Yu-feng

    2017-07-01

    As the cost of hot metal is reduced for iron ore prices are falling in the international market, more and more electric arc furnace (EAF) steelmaking enterprises use partial hot metal instead of scrap as raw materials to reduce costs and the power consumption. In this paper, carbon emissions based on 1,000 kg molten steel by charging hot metal in EAF steelmaking is studied. Based on the analysis of material and energy balance calculation in EAF, the results show that 146.9, 142.2, 137.0, and 130.8 kg/t of carbon emissions are produced at a hot metal ratio of 0 %, 30 %, 50 %, and 70 %, while 143.4, 98.5, 65.81, and 31.5 kg/t of carbon emissions are produced at a hot metal ratio of 0 %, 30 %, 50 %, and 70 % by using gas waste heat utilization (coal gas production) for EAF steelmaking unit process. However, carbon emissions are increased by charging hot metal for the whole blast furnace-electric arc furnace (BF-EAF) steelmaking process. In the condition that the hot metal produced by BF is surplus, as carbon monoxide in gas increased by charging hot metal, the way of coal gas production can be used for waste heat utilization, which reduces carbon emissions in EAF steelmaking unit process.

  6. Semisolid slurry of 7A04 aluminum alloy prepared by electromagnetic stirring and Sc, Zr additions

    Directory of Open Access Journals (Sweden)

    Jun-wen Zhao

    2017-05-01

    Full Text Available Slurry preparation is one of the most critical steps for semisolid casting, and its primary goal is to prepare slurry with uniformly distributed fine globules. In this work, electromagnetic stirring (EMS and the addition of Sc and Zr elements were used to prepare semisolid slurry of 7A04 aluminum alloy in a large diameter slurry maker. The effects of different treatments on the microstructure, composition and their radial homogeneity were investigated. The results show that, compared to the slurry without any treatment, large volume slurry with finer and more uniform microstructure can be obtained when treated by EMS, Sc, or Zr additions individually. EMS is more competent in the microstructural and chemical homogenization of the slurry while Sc and Zr additions are more excellent in its microstructural refinement. The combined treatment of EMS, Sc and Zr produces premium 7A04 aluminum alloy slurry with uniformly distributed fine α-Al globules and composition. The interaction mechanism between EMS and Sc and Zr additions was also discussed.

  7. Gastric emptying time (GET) with Tc-99m-labeled semisolid meal in diabetic patients

    International Nuclear Information System (INIS)

    Tada, Akira; Koizumi, Kiyoshi; Aburano, Tamio; Bunko, Hisashi; Tonami, Norihisa

    1984-01-01

    Measurement of gastric emptying in diabetic gastroenteropathy is of interest because of the gastric atony that may produce signs and symptoms of visceral neuropathy. The purpose of this study is to present the result of GET measurements in diabetic patients. The correlation between GET and complications, fasting blood sugar (FBS), duration of disease, age, sex, and HbAlc was evaluated. Included in this study were 21 diabetic patients. Fourteen patients had diabetic complications such as peripheral neuropathy, autonomic neuropathy, nephropathy and retinopathy. Following an overnight fast, semisolid test meal mixed with 200 uCi of Tc-99m Sn-colloid was ingested by the patients. In nine normal volunteers, the GET range previously established by this method in our institution was from 47 to 78 minutes (mean 62.5 +- 7.7). In the patients with diabetic complication, particulary with triopathy, GET was significantly prolonged compared to those of normal subjects and diabetic patients without complication. On the contrary, four out of seven patients without complications, showed rapid emptying than normal subjects. This rapid emptying may reveal the early stage of pathophysiological change in diabetics. No correlation between GET and FBS, duration of disease, age, sex and HbAlc was seen. This test of radiolabeled semisolid meal was found to provide a convenient, safe and effective diagnostic tool to examine gastric emptying function in diabetic patients. (author)

  8. Gastric emptying time (GET) with Tc-99m-labeled semisolid meal in diabetic patients

    Energy Technology Data Exchange (ETDEWEB)

    Tada, Akira; Koizumi, Kiyoshi; Aburano, Tamio; Bunko, Hisashi; Tonami, Norihisa [Kanazawa Univ. (Japan). School of Medicine

    1984-01-01

    Measurement of gastric emptying in diabetic gastroenteropathy is of interest because of the gastric atony that may produce signs and symptoms of visceral neuropathy. The purpose of this study is to present the result of GET measurements in diabetic patients. The correlation between GET and complications, fasting blood sugar (FBS), duration of disease, age, sex, and HbAlc was evaluated. Included in this study were 21 diabetic patients. Fourteen patients had diabetic complications such as peripheral neuropathy, autonomic neuropathy, nephropathy and retinopathy. Following an overnight fast, semisolid test meal mixed with 200 uCi of Tc-99m Sn-colloid was ingested by the patients. In nine normal volunteers, the GET range previously established by this method in our institution was from 47 to 78 minutes (mean 62.5 +- 7.7). In the patients with diabetic complication, particulary with triopathy, GET was significantly prolonged compared to those of normal subjects and diabetic patients without complication. On the contrary, four out of seven patients without complications, showed rapid emptying than normal subjects. This rapid emptying may reveal the early stage of pathophysiological change in diabetics. No correlation between GET and FBS, duration of disease, age, sex and HbAlc was seen. This test of radiolabeled semisolid meal was found to provide a convenient, safe and effective diagnostic tool to examine gastric emptying function in diabetic patients.

  9. Volcano Relation for the Deacon Process over Transition-Metal Oxides

    DEFF Research Database (Denmark)

    Studt, Felix; Abild-Pedersen, Frank; Hansen, Heine Anton

    2010-01-01

    We establish an activity relation for the heterogeneous catalytic oxidation of HCI (the Deacon Process) over rutile transition-metal oxide catalysts by combining density functional theory calculations (DFT) with microkinetic modeling. Linear energy relations for the elementary reaction steps...

  10. Fully solution-processed organic solar cells on metal foil substrates

    KAUST Repository

    Gaynor, Whitney; Lee, Jung-Yong; Peumans, Peter

    2009-01-01

    We demonstrate fully solution-processed organic photovoltaic cells on metal foil substrates with power conversion efficiencies similar to those obtained in devices on transparent substrates. The cells are based on the regioregular poly- (3

  11. An expert system for process planning of sheet metal parts produced ...

    Indian Academy of Sciences (India)

    Sachin Salunkhe

    set of production rules and frames for process planning of axisymmetric deep ... parameters for design of stamping die for manufacturing of circular cup with ..... proper sequence of operations to manufacture sheet metal part correctly and ...

  12. Design and In-Situ Processing of Metal-Ceramic and Ceramic-Ceramic Microstructures

    National Research Council Canada - National Science Library

    Sass, Stephen

    1997-01-01

    .... Metal-ceramic microstructures have been synthesized in situ by a variety of novel processing techniques, including the partial reduction of oxide compounds and displacement reactions and sol-gel...

  13. Radiative proton-capture nuclear processes in metallic hydrogen

    International Nuclear Information System (INIS)

    Ichimaru, Setsuo

    2001-01-01

    Protons being the lightest nuclei, metallic hydrogen may exhibit the features of quantum liquids most relevant to enormous enhancement of nuclear reactions; thermonuclear and pycnonuclear rates and associated enhancement factors of radiative proton captures of high-Z nuclei as well as of deuterons are evaluated. Atomic states of high-Z impurities are determined in a way consistent with the equations of state and screening characteristics of the metallic hydrogen. Rates of pycnonuclear p-d reactions are prodigiously high at densities ≥20 g/cm 3 , pressures ≥1 Gbar, and temperatures ≥950 K near the conditions of solidification. It is also predicted that proton captures of nuclei such as C, N, O, and F may take place at considerable rates, owing to strong screening by K-shell electrons, if the densities ≥60-80 g/cm 3 , the pressures ≥7-12 Gbar, and the temperatures just above solidification. The possibilities and significance of pycnonuclear p-d fusion experiments are specifically remarked

  14. Experimental Methodology for Determining Optimum Process Parameters for Production of Hydrous Metal Oxides by Internal Gelation

    Energy Technology Data Exchange (ETDEWEB)

    Collins, J.L.

    2005-10-28

    The objective of this report is to describe a simple but very useful experimental methodology that was used to determine optimum process parameters for preparing several hydrous metal-oxide gel spheres by the internal gelation process. The method is inexpensive and very effective in collection of key gel-forming data that are needed to prepare the hydrous metal-oxide microspheres of the best quality for a number of elements.

  15. 40 CFR Table 4 to Subpart Vvvvvv... - Emission Limits and Compliance Requirements for Metal HAP Process Vents

    Science.gov (United States)

    2010-07-01

    ... Requirements for Metal HAP Process Vents 4 Table 4 to Subpart VVVVVV of Part 63 Protection of Environment... of Part 63—Emission Limits and Compliance Requirements for Metal HAP Process Vents As required in § 63.11496(f), you must comply with the requirements for metal HAP process vents as shown in the...

  16. Process and equipment qualification of the ceramic and metal waste forms for spent fuel treatment

    International Nuclear Information System (INIS)

    Marsden, Ken; Knight, Collin; Bateman, Kenneth; Westphal, Brian; Lind, Paul

    2005-01-01

    The electrometallurgical process for treating sodium-bonded spent metallic fuel at the Materials and Fuels Complex of the Idaho National Laboratory separates actinides and partitions fission products into two waste forms. The first is the metal waste form, which is primarily composed of stainless steel from the fuel cladding. This stainless steel is alloyed with 15w% zirconium to produce a very corrosion-resistant metal which binds noble metal fission products and residual actinides. The second is the ceramic waste form which stabilizes fission product-loaded chloride salts in a sodalite and glass composite. These two waste forms will be packaged together for disposal at the Yucca Mountain repository. Two production-scale metal waste furnaces have been constructed. The first is in a large argon-atmosphere glovebox and has been used for equipment qualification, process development, and process qualification - the demonstration of process reliability for production of the DOE-qualified metal waste form. The second furnace will be transferred into a hot cell for production of metal waste. Prototype production-scale ceramic waste equipment has been constructed or procured; some equipment has been qualified with fission product-loaded salt in the hot cell. Qualification of the remaining equipment with surrogate materials is underway. (author)

  17. Standard practice for process compensated resonance testing via swept sine input for metallic and Non-Metallic parts

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2010-01-01

    1.1 This practice describes a general procedure for using the process compensated resonance testing (PCRT) via swept sine input method to identify metallic and non-metallic parts’ resonant pattern differences that can be used to indentify parts with anomalies causing deficiencies in the expected performance of the part in service. This practice is intended for use with instruments capable of exciting, measuring, recording, and analyzing multiple whole body mechanical vibration resonant frequencies within parts exhibiting acoustical ringing in the audio, or ultrasonic, resonant frequency ranges, or both. PCRT is used in the presence of manufacturing process variance to distinguish acceptable parts from those containing significant anomalies in physical characteristics expected to significantly alter the performance. Such physical characteristics include, but are not limited to, cracks, voids, porosity, shrink, inclusions, discontinuities, grain and crystalline structure differences, density related anomalies...

  18. Plasma Processing of Metallic and Semiconductor Thin Films in the Fisk Plasma Source

    Science.gov (United States)

    Lampkin, Gregory; Thomas, Edward, Jr.; Watson, Michael; Wallace, Kent; Chen, Henry; Burger, Arnold

    1998-01-01

    The use of plasmas to process materials has become widespread throughout the semiconductor industry. Plasmas are used to modify the morphology and chemistry of surfaces. We report on initial plasma processing experiments using the Fisk Plasma Source. Metallic and semiconductor thin films deposited on a silicon substrate have been exposed to argon plasmas. Results of microscopy and chemical analyses of processed materials are presented.

  19. The effect of tooling deformation on process control in multistage metal forming

    NARCIS (Netherlands)

    Havinga, Gosse Tjipke; van den Boogaard, Antonius H.; Chinesta, F; Cueto, E; Abisset-Chavanne, E.

    2016-01-01

    Forming of high-strength steels leads to high loads within the production process. In multistage metal forming, the loads in different process stages are transferred to the other stages through elastic deformation of the stamping press. This leads to interactions between process steps, affecting the

  20. A case in support of implementing innovative bio-processes in the metal mining industry.

    Science.gov (United States)

    Sánchez-Andrea, Irene; Stams, Alfons J M; Weijma, Jan; Gonzalez Contreras, Paula; Dijkman, Henk; Rozendal, Rene A; Johnson, D Barrie

    2016-06-01

    The metal mining industry faces many large challenges in future years, among which is the increasing need to process low-grade ores as accessible higher grade ores become depleted. This is against a backdrop of increasing global demands for base and precious metals, and rare earth elements. Typically about 99% of solid material hauled to, and ground at, the land surface currently ends up as waste (rock dumps and mineral tailings). Exposure of these to air and water frequently leads to the formation of acidic, metal-contaminated run-off waters, referred to as acid mine drainage, which constitutes a severe threat to the environment. Formation of acid drainage is a natural phenomenon involving various species of lithotrophic (literally 'rock-eating') bacteria and archaea, which oxidize reduced forms of iron and/or sulfur. However, other microorganisms that reduce inorganic sulfur compounds can essentially reverse this process. These microorganisms can be applied on industrial scale to precipitate metals from industrial mineral leachates and acid mine drainage streams, resulting in a net improvement in metal recovery, while minimizing the amounts of leachable metals to the tailings storage dams. Here, we advocate that more extensive exploitation of microorganisms in metal mining operations could be an important way to green up the industry, reducing environmental risks and improving the efficiency and the economy of metal recovery. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  1. Design, fabrication, and application of a directional thermal processing system for controlled devitrification of metallic glasses

    Science.gov (United States)

    Meyer, Megan Anne Lamb

    The potential of using metallic glass as a pathway to obtaining novel morphologies and metastable phases has been garnering attention since their discovery. Several rapid solidification techniques; such as gas atomization, melt spinning, laser melting, and splat quenching produce amorphous alloys. A directional thermal processing system (DTPS) was designed, fabricated and characterized for the use of zone processing or gradient-zone processing of materials. Melt-spun CuZr metallic glass alloy was subjected to the DTPS and the relaxation and crystallization responses of the metallic glass were characterized. A range of processing parameters were developed and analyzed that would allow for devitrification to occur. The relaxation and crystallization responses were compared with traditional heat treatment methods of metallic glasses. The new processing method accessed equilibrium and non-equilibrium phases of the alloy and the structures were found to be controllable and sensitive to processing conditions. Crystallized fraction, crystallization onset temperature, and structural relaxation were controlled through adjusting the processing conditions, such as the hot zone temperature and sample velocity. Reaction rates computed from isothermal (TTT) transformation data were not found to be reliable, suggesting that the reaction kinetics are not additive. This new processing method allows for future studying of the thermal history effects of metallic glasses.

  2. High peak power processing up to 100 MV/M on various metallic samples

    International Nuclear Information System (INIS)

    Luong, M.; Bonin, B.; Safa, H.

    1996-01-01

    The high peak power processing (HPPP) is a well established way to reduce electronic field emission from radiofrequency (RF) metallic surfaces. The processing occurs because of some kind of instability destroys the emitter, but the basic physical mechanism at work has not yet been clearly identified. RF processing experiments on samples of restricted area, are described with well localized artificial emitting sites (protrusions from scratches on the sample surface). In order to disentangle the role of thermal and mechanical effects, in the processing, the samples were made from metals with different melting temperatures and tensile strengths. (author)

  3. High peak power processing up to 100 MV/m on various metallic samples

    International Nuclear Information System (INIS)

    Luong, M.; Bonin, B.; Safa, H.; Le Goff, A.

    1996-01-01

    The high peak power processing (HPPP) is a well established way to reduce electronic field emission from radiofrequency (RF) metallic surfaces. The processing occurs because of some kind of instability destroys the emitter, but the basic physical mechanism at work has not yet been clearly identified. The present study describes RF processing experiments on samples of restricted area, with well localized artificial emitting sites (protrusions from scratches on the sample surface). In order to disentangle the role of thermal and mechanical effects in the processing, the samples were made from metals with different melting temperatures and tensile strengths. (author)

  4. Arc plasma assisted rotating electrode process for preparation of metal pebbles

    International Nuclear Information System (INIS)

    Mohanty, T.; Tripathi, B.M.; Mahata, T.; Sinha, P.K.

    2014-01-01

    Spherical beryllium pebbles of size ranging from 0.2-2 mm are required as neutron multiplying material in solid Test Blanket Module (TBM) of International Thermonuclear Experimental Reactor (ITER). Rotating electrode process (REP) has been identified as a suitable technique for preparation of beryllium pebbles. In REP, arc plasma generated between non-consumable electrode (cathode) and rotating metal electrode (anode) plays a major role for continuous consumption of metal electrode and preparation of spherical metal pebbles. This paper focuses on description of the process, selection of sub-systems for development of REP experimental set up and optimization of arc parameters, such as, cathode geometry, arc current, arc voltage, arc gap and carrier gas flow rate for preparation of required size spherical metal pebbles. Other parameters which affect the pebbles sizes are rotational speed, metal electrode diameter and physical properties of the metal. As beryllium is toxic in nature its surrogate metals such as stainless steel (SS) and Titanium (Ti) were selected to evaluate the performance of the REP equipment. Several experiments were carried out using SS and Ti electrode and process parameters have been optimized for preparation of pebbles of different sizes. (author)

  5. A study of liberation and separation process of metals from printed circuit boards (PCBs) scrap

    International Nuclear Information System (INIS)

    Noorliyana, H.A.; Zaheruddin, K.; Mohd Fazlul Bari; M. Sri Asliza; Nurhidayah, A.Z.; Kamarudin, H.

    2009-01-01

    Since the metallic elements are covered with or encapsulated by various plastic or ceramic materials on printed circuit boards, a mechanical pre-treatment process allowing their liberation and separation is first needed in order to facilitate their efficient extraction with hydrometallurgy route. Even though many studies have been performed on the mechanical pre-treatment processing for the liberation and separation of the metallic components of printed circuit boards scrap, further studies are required to pave the way for efficient recycling of waste printed circuit boards through a combination of mechanical pre-treatment and hydrometallurgical technology. In this work, a fundamental study has been carried out on the mechanical pre-treatment that is necessary to recover metallic concentrates from printed circuit boards scraps. The most important problem is to separate or release particles from the associated gangue minerals at the possible liberation particle size. The distribution of metallic elements has been also investigated in relation to the particle size of the milled printed circuit boards. The samples of printed circuit boards were separated into the magnetic and non-magnetic fractions by Rare-earth Roll Magnetic separator. Thereafter, the magnetic and non-magnetic fractions were separated to heavy fraction (metallic elements) and light fraction (plastic) by Mozley Laboratory Table Separator. The recovery ratios and the evaluation of the metallic concentrates recovered by each separation process were also investigated. This study is expected to provide useful data for the efficient mechanical separation of metallic components from printed circuit boards scraps. (author)

  6. Demonstration of an N7 integrated fab process for metal oxide EUV photoresist

    Science.gov (United States)

    De Simone, Danilo; Mao, Ming; Kocsis, Michael; De Schepper, Peter; Lazzarino, Frederic; Vandenberghe, Geert; Stowers, Jason; Meyers, Stephen; Clark, Benjamin L.; Grenville, Andrew; Luong, Vinh; Yamashita, Fumiko; Parnell, Doni

    2016-03-01

    Inpria has developed a directly patternable metal oxide hard-mask as a robust, high-resolution photoresist for EUV lithography. In this paper we demonstrate the full integration of a baseline Inpria resist into an imec N7 BEOL block mask process module. We examine in detail both the lithography and etch patterning results. By leveraging the high differential etch resistance of metal oxide photoresists, we explore opportunities for process simplification and cost reduction. We review the imaging results from the imec N7 block mask patterns and its process windows as well as routes to maximize the process latitude, underlayer integration, etch transfer, cross sections, etch equipment integration from cross metal contamination standpoint and selective resist strip process. Finally, initial results from a higher sensitivity Inpria resist are also reported. A dose to size of 19 mJ/cm2 was achieved to print pillars as small as 21nm.

  7. Thomson scattering diagnostics of steady state and pulsed welding processes without and with metal vapor

    International Nuclear Information System (INIS)

    Kühn-Kauffeldt, M; Schein, J; Marqués, J-L

    2015-01-01

    Thomson scattering is applied to measure temperature and density of electrons in the arc plasma of the direct current gas tungsten arc welding (GTAW) process and pulsed gas metal arc welding (GMAW) process. This diagnostic technique allows to determine these plasma parameters independent from the gas composition and heavy particles temperature. The experimental setup is adapted to perform measurements on stationary as well as transient processes. Spatial and temporal electron temperature and density profiles of a pure argon arc in the case of the GTAW process and argon arc with the presence of aluminum metal vapor in the case of the GMAW process were obtained. Additionally the data is used to estimate the concentration of the metal vapor in the GMAW plasma. (fast track communication)

  8. Determination of Optimal Parameters for Diffusion Bonding of Semi-Solid Casting Aluminium Alloy by Response Surface Methodology

    Directory of Open Access Journals (Sweden)

    Kaewploy Somsak

    2015-01-01

    Full Text Available Liquid state welding techniques available are prone to gas porosity problems. To avoid this solid state bonding is usually an alternative of preference. Among solid state bonding techniques, diffusion bonding is often employed in aluminium alloy automotive parts welding in order to enhance their mechanical properties. However, there has been no standard procedure nor has there been any definitive criterion for judicious welding parameters setting. It is thus a matter of importance to find the set of optimal parameters for effective diffusion bonding. This work proposes the use of response surface methodology in determining such a set of optimal parameters. Response surface methodology is more efficient in dealing with complex process compared with other techniques available. There are two variations of response surface methodology. The one adopted in this work is the central composite design approach. This is because when the initial upper and lower bounds of the desired parameters are exceeded the central composite design approach is still capable of yielding the optimal values of the parameters that appear to be out of the initially preset range. Results from the experiments show that the pressing pressure and the holding time affect the tensile strength of jointing. The data obtained from the experiment fits well to a quadratic equation with high coefficient of determination (R2 = 94.21%. It is found that the optimal parameters in the process of jointing semi-solid casting aluminium alloy by using diffusion bonding are the pressing pressure of 2.06 MPa and 214 minutes of the holding time in order to achieve the highest tensile strength of 142.65 MPa

  9. Platinum group metal recovery and catalyst manufacturing process

    Energy Technology Data Exchange (ETDEWEB)

    Chung, H. S.; Kim, Y. S.; Yoo, J. H.; Lee, H. S.; Ahn, D. H.; Kim, K. R.; Lee, S. H.; Paek, S. W.; Kang, H. S.

    1998-03-01

    The fission product nuclides generated during the irradiation of reactor fuel include many useful elements, among them platinum group metal such as ruthenium, rhodium and palladium which are of great industrial importance, occur rarely in nature and are highly valuable. In this research, the authors reviewed various PGM recovery methods. Recovery of palladium from seven-component simulated waste solution was conducted by selective precipitation method. The recovery yield was more than 99.5% and the purity of the product was more than 99%. Wet-proof catalyst was prepared with the recovered palladium. The specific surface area of the catalyst support was more than 400 m{sup 2}/g. The content of palladium impregnated on the support was 10 wt.%. Hydrogen isotope exchange efficiency of 93 % to equilibrium with small amount of the catalyst was obtained. It was turned out possible to consider using such palladium or other very low active PGM materials in applications where its actively is unimportant as in nuclear industries. (author). 63 refs., 38 tabs., 36 figs.

  10. Metal alkoxides as starting materials for hydrolysis processes

    International Nuclear Information System (INIS)

    Mukhtar, Omaima Awad

    1999-12-01

    In this thesis the preparation of some metal alkoxides and their hydrolysis products were studied. The characteristic of each prepared alkoxides and their hydrolyzates were determined. Tetra ethoxysilane was prepared by the elemental route (the reaction of silicon powder with liquid ethanol) in the presence of tin ethoxide as a catalyst. The use of tin alkoxide is considered one of the most developed ways used recently in chemistry, compared to the usage of acids and bases as catalyst previously. It had been confirmed by the usage of (infrared) IR spectroscopy, the structure of the prepared material. Also tin isopropoxide had been prepared and hydrolyzed. Ethoxides of aluminium, magnesium and tin had been prepared by the elemental route. The gelation product had been analyzed. tetraethoxysilane had been also prepared by the halosilane route. Isopropoxide of each aluminium, magnesium and tin had been synthesized, hydrolyzed, allowed to gel and analyzed by IR (infrared) spectroscopy and gas-liquid chromatography. However, results obtained indicated that tin ethoxide is an effective catalyst in the direct synthesis of tetraethoxysilane from silicon powder and liquid ethanol. Gas-liquid chromatography, infra-red (IR) analysis showed that the final reaction product was tetraethoxysilane. (Author)

  11. Influence of surface effects on subsecond processes in liquid metals

    International Nuclear Information System (INIS)

    Tkachenko, S.I.; Vorob'ev, V.S.; Khishchenko, K.V.

    2001-01-01

    Full Text: We discuss a problem of experimental-data interpretation during subsecond measurements of thermophysical properties of matter at high temperatures and pressures. Peculiarity of these measurements is optical opaqueness of matter under interesting conditions (T∼1 eV, ρ∼10 4 kg m -3 ), so only at assuming of bulk specimen uniformity one can obtain a temperature dependencies of the specific properties of matter. Changing circuit current and changing sample geometry we can avoid a development of hydromagnetic instability and decrease a nonuniform heating due to skin effect. As temperature of wire surface reaches the boiling temperature under normal pressure so part of internal energy is lost because of evaporation and surface radiation at high temperature. So one can register a surface temperature and ascribe it to the whole sample bulk. Computer simulation of wire explosion taking into account surface radiation losses was carried out. Typical phase tracks for matter were obtained in both case as in consideration of radiation losses as without it. Comparison of the results with data concerning to isobaric-expansion experiments and semi-empirical multi-phase equation of state were carried out. It was proposed uniformity criterion for investigation of thermophysical properties of liquid metal by subsecond wire explosion. (author)

  12. Heat-processing method and facility for helium-containing metal material

    International Nuclear Information System (INIS)

    Kato, Takahiko; Kodama, Hideyo; Matsumoto, Toshimi; Aono, Yasuhisa; Nagata, Tetsuya; Hattori, Shigeo; Kaneda, Jun-ya; Ono, Shigeki.

    1996-01-01

    Electric current is supplied to an objective portion of a He-containing metal material to be applied with heat processing without causing melting, to decrease the He content of the portion. Subsequently, the defect portion of the tissues of the He-containing metal is modified by heating the portion with melting. Since electric current can be supplied to the metal material in a state where the metal material is heated and the temperature thereof is elevated, an effect of further reducing the He content can be obtained. Further, if the current supply and/or the heating relative to the metal material is performed in a vacuum or inert gas atmosphere, an effect of reducing the degradation of the surface of the objective portion to be supplied with electric current can be obtained. (T.M.)

  13. Effects of slag composition and process variables on decontamination of metallic wastes by melt refining

    International Nuclear Information System (INIS)

    Heshmatpour, B.; Copeland, G.L.

    1981-01-01

    Melt refining has been suggested as an alternative for decontamination and volume reduction of low-level-contaminated metallic wastes. Knowledge of metallurgical and thermochemical aspects of the process is essential for effective treatment of various metals. Variables such as slag type and composition, melting technique, and refractory materials need to be identified for each metal or alloy. Samples of contaminated metals were melted with fluxes by resistance furnace or induction heating. The resulting ingots as well as the slags were analyzed for their nuclide contents, and the corresponding partition ratios were calculated. Compatibility of slags and refractories was also investigated, and proper refractory materials were identified. Resistance furnace melting appeared to be a better melting technique for nonferrous scrap, while induction melting was more suitable for ferrous metals. In general uranium contents of the metals, except for aluminum, could be reduced to as low as 0.01 to 0.1 ppM by melt refining. Aluminum could be decontaminated to about 1 to 2 ppM U when certain fluoride slags were used. The extent of decontamination was not very sensitive to slag type and composition. However, borosilicate and basic oxidizing slags were more effective on ferrous metals and Cu; NaNO 3 -NaCl-NaOH type fluxes were desirable for Zn, Pb, and Sn; and fluoride type slags were effective for decontamination of Al. Recrystallized alumina proved to be the most compatible refractory for melt refining both ferrous and nonferrous metals, while graphite was suitable for nonferrous metal processing. In conclusion, melt refining is an effective technique for volume reduction ad decontamination of contaminated metal scrap when proper slags, melting technique, and refractories are used

  14. Chemical Separation of Fission Products in Uranium Metal Ingots from Electrolytic Reduction Process

    International Nuclear Information System (INIS)

    Lee, Chang-Heon; Kim, Min-Jae; Choi, Kwang-Soon; Jee, Kwang-Yong; Kim, Won-Ho

    2006-01-01

    Chemical characterization of various process materials is required for the optimization of the electrolytic reduction process in which uranium dioxide, a matrix of spent PWR fuels, is electrolytically reduced to uranium metal in a medium of LiCl-Li 2 O molten at 650 .deg. C. In the uranium metal ingots of interest in this study, residual process materials and corrosion products as well as fission products are involved to some extent, which further adds difficulties to the determination of trace fission products. Besides it, direct inductively coupled plasma atomic emission spectrometric (ICP-AES) analysis of uranium bearing materials such as the uranium metal ingots is not possible because a severe spectral interference is found in the intensely complex atomic emission spectra of uranium. Thus an adequate separation procedure for the fission products should be employed prior to their determinations. In present study ion exchange and extraction chromatographic methods were adopted for selective separation of the fission products from residual process materials, corrosion products and uranium matrix. The sorption behaviour of anion and tri-nbutylphosphate (TBP) extraction chromatographic resins for the metals in acidic solutions simulated for the uranium metal ingot solutions was investigated. Then the validity of the separation procedure for its reliability and applicability was evaluated by measuring recoveries of the metals added

  15. Application of boiling liquid metals in industrial processes

    International Nuclear Information System (INIS)

    Kottowski, H.M.; Savatteri, C.; Mol, M.; Fiebelmann, P.

    1976-01-01

    The successful development of coated particle fuel and of special graphites for the structural components of VHTR-cores has opened up the possibility of an economical nuclear heat source to provide temperatures in excess of 1000 0 C as ''process heat application''. In order to exploit this temperature potential the heat has to be transferred to the appropriate chemical processes and there is little doubt that the only practical way of achieving this on a large scale is by the use of intermediate heat exchanger systems. The aim of the paper is to exhibit a technological possibility, both to substitute the secondary circuit of the sodium cooled reactors and to transfer the heat from the VHTR to the chemical process plant which satisfies the safety requirements and demonstrates technological advantages

  16. Morphology evolution and nanostructure of chemical looping transition metal oxide materials upon redox processes

    International Nuclear Information System (INIS)

    Qin, Lang; Cheng, Zhuo; Guo, Mengqing; Fan, Jonathan A.; Fan, Liang-Shih

    2017-01-01

    Transition metal are heavily used in chemical looping technologies because of their high oxygen carrying capacity and high thermal reactivity. These oxygen activities result in the oxide formation and oxygen vacancy formation that affect the nanoscale crystal phase and morphology within these materials and their subsequent bulk chemical behavior. In this study, two selected earlier transition metals manganese and cobalt as well as two selected later transition metals copper and nickel that are important to chemical looping reactions are investigated when they undergo cyclic redox reactions. We found Co microparticles exhibited increased CoO impurity presence when oxidized to Co_3O_4 upon cyclic oxidation; CuO redox cycles prefer to be limited to a reduced form of Cu_2O and an oxidized form of CuO; Mn microparticles were oxidized to a mixed phases of MnO and Mn_3O_4, which causes delamination during oxidation. For Ni microparticles, a dense surface were observed during the redox reaction. The atomistic thermodynamics methods and density functional theory (DFT) calculations are carried out to elucidate the effect of oxygen dissociation and migration on the morphological evolution of nanostructures during the redox processes. Our results indicate that the earlier transition metals (Mn and Co) tend to have stronger interaction with O_2 than the later transition metals (Ni and Cu). Also, our modified Brønsted−Evans−Polanyi (BEP) relationship for reaction energies and total reaction barriers reveals that reactions of earlier transition metals are more exergonic and have lower oxygen dissociation barriers than those of later transition metals. In addition, it was found that for these transition metal oxides the oxygen vacancy formation energies increase with the depth. The oxide in the higher oxidation state of transition metal has lower vacancy formation energy, which can facilitate forming the defective nanostructures. The fundamental understanding of these metal

  17. Novel Chemical Process for Producing Chrome Coated Metal

    OpenAIRE

    Pelar, Christopher; Greenaway, Karima; Zea, Hugo; Wu, Chun-Hsien; Luhrs, Claudia C.; Phillips, Jonathan

    2018-01-01

    The article of record as published may be found at http://dx.doi.org/10.3390/ma11010078 This work demonstrates that a version of the Reduction Expansion Synthesis (RES) process, Cr-RES, can create a micron scale Cr coating on an iron wire. The process involves three steps. I. A paste consisting of a physical mix of urea, chrome nitrate or chrome oxide, and water is prepared. II. An iron wire is coated by dipping. III. The coated, and dried, wire is heated to ~800 ◦C for 10 min in a tube fu...

  18. Leaching characteristics of the metal waste form from the electrometallurgical treatment process: Product consistency testing

    International Nuclear Information System (INIS)

    Johnson, S. G.; Keiser, D. D.; Frank, S. M.; DiSanto, T.; Noy, M.

    1999-01-01

    Argonne National Laboratory is developing an electrometallurgical treatment for spent fuel from the experimental breeder reactor II. A product of this treatment process is a metal waste form that incorporates the stainless steel cladding hulls, zirconium from the fuel and the fission products that are noble to the process, i.e., Tc, Ru, Nb, Pd, Rh, Ag. The nominal composition of this waste form is stainless steel/15 wt% zirconium/1--4 wt% noble metal fission products/1--2 wt % U. Leaching results are presented from several tests and sample types: (1) 2 week monolithic immersion tests on actual metal waste forms produced from irradiated cladding hulls, (2) long term (>2 years) pulsed flow tests on samples containing technetium and uranium and (3) crushed sample immersion tests on cold simulated metal waste form samples. The test results will be compared and their relevance for waste form product consistency testing discussed

  19. Behavior of solid matters and heavy metals during conductive drying process of sewage sludge

    Directory of Open Access Journals (Sweden)

    Jianping Luo

    2016-12-01

    Full Text Available Behavior of solid matters and heavy metals during conductive drying process of sewage sludge was evaluated in a sewage sludge disposal center in Beijing, China. The results showed most of solid matters could be retained in the dried sludge after drying. Just about 3.1% of solid matters were evaporated with steam mainly by the form of volatile fatty acids. Zn was the dominant heavy metal in the sludge, followed by Cu, Cr, Pb, Ni, Hg, and Cd. The heavy metals in the condensate were all below the detection limit except Hg. Hg in the condensate accounted for less than 0.1% of the total Hg. It can be concluded that most of the heavy metals are also retained in the dried sludge during the drying process, but their bioavailability could be changed significantly. The results are useful for sewage sludge utilization and its condensate treatment.

  20. Morphology Analysis and Process Research on Novel Metal Fused-coating Additive Manufacturing

    Science.gov (United States)

    Wang, Xin; Wei, Zheng ying; Du, Jun; Ren, Chuan qi; Zhang, Shan; Zhang, Zhitong; Bai, Hao

    2017-12-01

    Existing metal additive manufacturing equipment has high capital costs and slow throughput printing. In this paper, a new metal fused-coating additive manufacturing (MFCAM) was proposed. Experiments of single-track formation were conducted using MFCAM to validate the feasibility. The low melting alloy was selected as the forming material. Then, the effect of process parameters such as the flow rate, deposition velocity and initial distance on the forming morphology. There is a strong coupling effect between the single track forming morphology. Through the analysis of influencing factors to improve the forming quality of specimens. The experimental results show that the twice as forming efficiency as the metal droplet deposition. Additionally, the forming morphology and quality were analyzed by confocal laser scanning microscope and X-ray. The results show that the metal fused-coating process can achieve good surface morphology and without internal tissue defect.

  1. High Metal Removal Rate Process for Machining Difficult Materials

    Energy Technology Data Exchange (ETDEWEB)

    Bates, Robert; McConnell, Elizabeth

    2016-06-29

    Machining methods across many industries generally require multiple operations to machine and process advanced materials, features with micron precision, and complex shapes. The resulting multiple machining platforms can significantly affect manufacturing cycle time and the precision of the final parts, with a resultant increase in cost and energy consumption. Ultrafast lasers represent a transformative and disruptive technology that removes material with micron precision and in a single step manufacturing process. Such precision results from athermal ablation without modification or damage to the remaining material which is the key differentiator between ultrafast laser technologies and traditional laser technologies or mechanical processes. Athermal ablation without modification or damage to the material eliminates post-processing or multiple manufacturing steps. Combined with the appropriate technology to control the motion of the work piece, ultrafast lasers are excellent candidates to provide breakthrough machining capability for difficult-to-machine materials. At the project onset in early 2012, the project team recognized that substantial effort was necessary to improve the application of ultrafast laser and precise motion control technologies (for micromachining difficult-to-machine materials) to further the aggregate throughput and yield improvements over conventional machining methods. The project described in this report advanced these leading-edge technologies thru the development and verification of two platforms: a hybrid enhanced laser chassis and a multi-application testbed.

  2. Modelling the mechanical behaviour of metal powder during Die compaction process

    Directory of Open Access Journals (Sweden)

    G. Cricrì

    2016-07-01

    Full Text Available In this work, powder compaction process was investigated by using a numerical material model, which involves Mohr-Coulomb theory and an elliptical surface plasticity model. An effective algorithm was developed and implemented in the ANSYS finite element (FEM code by using the subroutine USERMAT. Some simulations were performed to validate the proposed metal powder material model. The interaction between metal powder and die walls was considered by means of contact elements. In addition to the analysis of metal powder behaviour during compaction, the actions transmitted to die were also investigated, by considering different friction coefficients. This information is particularly useful for a correct die design.

  3. Friction stir processed Al - Metal oxide surface composites: Anodization and optical appearance

    DEFF Research Database (Denmark)

    Gudla, Visweswara Chakravarthy; Jensen, Flemming; Canulescu, Stela

    2014-01-01

    Multiple-pass friction stir processing (FSP) was employed to impregnate metal oxide (TiO2, Y2O3 and CeO2) particles into the surface of an Aluminium alloy. The surface composites were then anodized in a sulphuric acid electrolyte. The effect of anodizing parameters on the resulting optical...... dark to greyish white. This is attributed to the localized microstructural and morphological differences around the metal oxide particles incorporated into the anodic alumina matrix. The metal oxide particles in the FSP zone electrochemically shadowed the underlying Al matrix and modified the local...

  4. ANALYSIS OF NONMAGNETIC METAL INDUCTION HEATING PROCESSES BY FLAT-TYPE CIRCULAR SOLENOIDAL FIELD

    Directory of Open Access Journals (Sweden)

    Yu. Batygin

    2016-12-01

    Full Text Available The article analyzes the electromagnetic processes in the system of induction heating with estimating the main characteristics of heating the non-magnetic sheet metal. The analytical expressions for numerical estimates of the induced current in terms of the phase of the excitation signal are presented. The dependence for the heating temperature of the considered circular sheet metal area for the time corresponding to the interval phase has been determined.

  5. Biorefine: Recovery of nutrients and metallic trace elements from different wastes by chemical and biochemical processes

    OpenAIRE

    Tarayre, Cédric; Fischer, Christophe; De Clercq, Lies; Michels, Evi; Meers, Erik; Buysse, Jeroen; Delvigne, Frank; Thonart, Philippe

    2014-01-01

    At present, most waste processing operations are not oriented towards the valorization of valuable reusable components such as nitrogen, phosphorus, potassium and even Metallic Trace Elements (MTEs). Currently, sewage sludge, for example is usually used as a fertilizer in agriculture, in energy production or in the field of construction. Ashes originating from sludge incineration contain heavy metals and minerals in large quantities. Manure is mainly used in agriculture, although considerable...

  6. Application of Multivariate Adaptive Regression Splines to Sheet Metal Bending Process for Springback Compensation

    Directory of Open Access Journals (Sweden)

    Dilan Rasim Aşkın

    2016-01-01

    Full Text Available An intelligent regression technique is applied for sheet metal bending processes to improve bending performance. This study is a part of another extensive study, automated sheet bending assistance for press brakes. Data related to material properties of sheet metal is collected in an online manner and fed to an intelligent system for determining the most accurate punch displacement without any offline iteration or calibration. The overall system aims to reduce the production time while increasing the performance of press brakes.

  7. Thermal Diffusion Processes in Metal-Tip-Surface Interactions: Contact Formation and Adatom Mobility

    DEFF Research Database (Denmark)

    Sørensen, Mads Reinholdt; Jacobsen, Karsten Wedel; Jonsson, Hannes

    1996-01-01

    and the surface can occur by a sequence of atomic hop and exchange processes which become active on a millisecond time scale when the tip is about 3-5 Angstrom from the surface. Adatoms on the surface are stabilized by the presence of the tip and energy barriers for diffusion processes in the region under the tip......We have carried out computer simulations to identify and characterize various thermally activated atomic scale processes that can play an important role in room temperature experiments where a metal tip is brought close to a metal surface. We find that contact formation between the tip...

  8. Experimental Investigation of Comparative Process Capabilities of Metal and Ceramic Injection Molding for Precision Applications

    DEFF Research Database (Denmark)

    Islam, Aminul; Giannekas, Nikolaos; Marhöfer, David Maximilian

    2016-01-01

    and discussion presented in the paper will be useful for thorough understanding of the MIM and CIM processes and to select the right material and process for the right application or even to combine metal and ceramic materials by molding to produce metal–ceramic hybrid components.......The purpose of this paper is to make a comparative study on the process capabilities of the two branches of the powder injection molding (PIM) process—metal injection molding (MIM) and ceramic injection molding (CIM), for high-end precision applications. The state-of-the-art literature does...

  9. Mydriatics release from solid and semi-solid ophthalmic formulations using different in vitro methods.

    Science.gov (United States)

    Pescina, Silvia; Macaluso, Claudio; Gioia, Gloria Antonia; Padula, Cristina; Santi, Patrizia; Nicoli, Sara

    2017-09-01

    The aim of the present paper was the development of semi-solid (hydrogels) and solid (film) ophthalmic formulations for the controlled release of two mydriatics: phenylephrine and tropicamide. The formulations - based on polyvinylalcohol and hyaluronic acid - were characterized, and release studies were performed with three different in vitro set-ups, i.e. Franz-type diffusion cell, vial method and inclined plane; for comparison, a solution and a commercial insert, both clinically used to induce mydriasis, were evaluated. Both gels and film allowed for a controlled release of drugs, appearing a useful alternative for mydriatics administration. However, the release kinetic was significantly influenced by the method used, highlighting the need for optimization and standardization of in vitro models for the evaluation of drug release from ophthalmic dosage forms.

  10. Mechanical behaviour of Nd-Fe-B alloys in the semi-solid state

    International Nuclear Information System (INIS)

    Oliveira, I.L.; Sinka, V.; Ferrante, M.

    1996-01-01

    Two alloys with composition Nd 17.6 Fe 75.3 B1.2 Cu 5.9 and Nd 15.9 Fe 77.7 B 5 Cu 1.4 were vacuum induction melted and cast into cylindrical ingots. Samples with 12.3 and 13 mm diameter were deformed with different rates and deformation ratios. One alloy was deformed at 800 deg C between two parallel disks under constant load. Results show that these alloys behave as no-Newtonian fluids. This fact gives a better understanding of both magnetic and crystallographic texture development. Also, changes were detected in the behaviour of semisolid in the course of deformation. (author)

  11. Synchrotron radiography of direct-shear in semi-solid alloys

    International Nuclear Information System (INIS)

    Gourlay, C M; Nagira, T; Nakatsuka, N; Yasuda, H; Dahle, A K; Uesugi, K

    2012-01-01

    Understanding phenomena occurring at the scale of the crystals during the deformation of semi-solid alloys is important for the development of physically-based rheological models. A range of deformation mechanisms have been proposed including agglomeration and disagglomeration, viscoplastic deformation of the solid skeleton, and granular phenomena such as jamming and dilatancy. This paper overviews in-situ experiments that directly image crystal-scale deformation mechanisms in equiaxed Al alloys at solid fractions shortly after the crystals have impinged to form a loose crystal network. Direct evidence is presented for granular deformation mechanisms including shear-induced dilation in both equiaxed-dendritic and globular microstructures. Modelling approaches suitable for capturing this behaviour are then discussed.

  12. In vitro propagation of Morus alba L. in semisolid culture medium.

    Directory of Open Access Journals (Sweden)

    Enrique Salas Barbosa

    2005-04-01

    Full Text Available Apical buds as explants were used with the objective to propagate in vitro mulberry plants in semisolid MS culture medium suplemented with 6-BAP and KIN in their establishment and, with different combinations of 6-BAP with ANA in the multiplication phase. In vitro plants were evaluated during the acclimatization phase. It is necessary to supplement the basal MS culture media with 0.5 mg.l-1 of 6-BAP to induce the sprouting and, 0.5 mg.l-1 of 6-BAP and 0.5 mg.l-1 of ANA to multiply the mulberry by nodal segments. In the acclimatization phase a 95% of survival, 30.2 cm of height, 9.8 leaves and 2.02 g.plant-1 of dry mass was observed. In vitro propagation of mulberry was achieved as an alternative for plants production. Key words: acclimatization, apical buds, establishment, explant, shooting

  13. Effects of grain refinement on the rheological behaviors of semisolid hypoeutectic Al-Si alloys

    International Nuclear Information System (INIS)

    Yan, M.; Luo, W.

    2007-01-01

    The paper experimentally investigated the effects of grain refinement on the rheological response of Al and hypoeutectic Al-Si alloys. Selected refiners included K 2 TiF 6 , K 2 TiF 6 plus graphite and Al-5Ti-B. The apparent viscosity of semisolid Al alloys was measured during solidification. Samples at different solid fractions were quenched to observe the microstructure. It was found that grain refinement drastically lowered the apparent viscosity of Al-Si alloys. Among selected refiners, the effect of Al-5Ti-B was the best. The effect of K 2 TiF 6 plus graphite was better than that of K 2 TiF 6 . Silicon contents in Al alloys affected the apparent viscosity. With increasing silicon content the apparent viscosity decreased, resulted from promotion of silicon to both refining effects of titanium and boron

  14. A mucosa-mimetic material for the mucoadhesion testing of thermogelling semi-solids.

    Science.gov (United States)

    da Silva, Jéssica Bassi; Khutoryanskiy, Vitaliy V; Bruschi, Marcos L; Cook, Michael T

    2017-08-07

    Mucosa-mimetic materials are synthetic substrates which aim to replace animal tissue in mucoadhesion experiments. One potential mucosa-mimetic material is a hydrogel comprised of N-acryloyl-d-glucosamine and 2-hydroxyethylmethacrylate, which has been investigated as a surrogate for animal mucosae in the mucoadhesion testing of tablets and solution formulations. This study aims to investigate the efficacy of this mucosa-mimetic material in the testing of thermogelling semi-solid formulations, which transition from solution to gel upon warming. Two methods for assessing mucoadhesion have been used; tensile testing and a flow-through system, which allow for investigation under dramatically different conditions. It was found that the mucosa-mimetic material was a good surrogate for buccal mucosa using both testing methods. This material may be used to replace animal tissue in these experiments, potentially reducing the number of laboratory animals used in studies of this type. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Semi-solid microbial fermentation of rice and wheat straw for protein enrichment and increased digestibility

    Energy Technology Data Exchange (ETDEWEB)

    Balasubramanya, R.H.; Bhatawdekar, S.P.

    1980-12-01

    Rice and wheat straws were hydrolyzed in various concentrations of sulfuric acid at different temperatures and different water: substrate ratios. The maximum amount of sugars of about 30-34% was released when heated at 121 degrees C with 0.5 N H2SO4 at a water: substrate ratio of 3:1. The pH of the hydrolyzed straws was raised to 5.0-5.5 with 5 N NH4OH. Such ammoniated straws were inoculated with the cultures of Penicillium funiculosum Thom. and Candida utilis (Henneb.) Lodder and Kreger-van Rij, and fermentation was carried out on semi-solid substrate for 5-7 days at room temperature. The fermentation resulted in 37-180% increase in crude protein, 23-100% increase in crude fat and 20-30% increase in the digestibility. (Refs. 29).

  16. Review on the processes of reduction and refining of metallic vanadium

    International Nuclear Information System (INIS)

    Mourao, M.B.; Capocchi, J.D.T.

    1982-01-01

    A literature survey on the processes of vanadium reduction and refining is presented. The results achieved by several research workers are comented. Enphasis is given to the aluminothermic reduction of V 2 O 5 followed by purification of the crude metal in an electron beam melting furnace or by high temperature molten salts electrolitic processes. (Author) [pt

  17. An expert system for process planning of sheet metal parts produced

    Indian Academy of Sciences (India)

    Process planning of sheet metal part is an important activity in the design of compound die. Traditional methods of carrying out this task are manual, tedious, time-consuming, error-prone and experiencebased. This paper describes the research work involved in the development of an expert system for process planning of ...

  18. Processes of conversion of a hot metal particle into aerogel through clusters

    Energy Technology Data Exchange (ETDEWEB)

    Smirnov, B. M., E-mail: bmsmirnov@gmail.com [Russian Academy of Sciences, Joint Institute for High Temperatures (Russian Federation)

    2015-10-15

    Processes are considered for conversion into a fractal structure of a hot metal micron-size particle that is located in a buffer gas or a gas flow and is heated by an external electric or electromagnetic source or by a plasma. The parameter of this heating is the particle temperature, which is the same in the entire particle volume because of its small size and high conductivity. Three processes determine the particle heat balance: particle radiation, evaporation of metal atoms from the particle surface, and heat transport to the surrounding gas due to its thermal conductivity. The particle heat balance is analyzed based on these processes, which are analogous to those for bulk metals with the small particle size, and its high temperature taken into account. Outside the particle, where the gas temperature is lower than on its surface, the formed metal vapor in a buffer gas flow is converted into clusters. Clusters grow as a result of coagulation until they become liquid, and then clusters form fractal aggregates if they are removed form the gas flow. Subsequently, associations of fractal aggregates join into a fractal structure. The rate of this process increases in medium electric fields, and the formed fractal structure has features of aerogels and fractal fibers. As a result of a chain of the above processes, a porous metal film may be manufactured for use as a filter or catalyst for gas flows.

  19. Process Stability of Ultrasonic-Wave-Assisted Gas Metal Arc Welding

    Science.gov (United States)

    Fan, Chenglei; Xie, Weifeng; Yang, Chunli; Lin, Sanbao; Fan, Yangyang

    2017-10-01

    As a newly developed arc welding method, ultrasonic-wave-assisted arc welding successfully introduced power ultrasound into the arc and weld pool, during which the ultrasonic acts on the top of the arc in the coaxial alignment direction. The advanced process for molten metals can be realized by using an additional ultrasonic field. Compared with the conventional gas metal arc welding (GMAW), the welding arc is compressed, the droplet size is decreased, and the droplet transfer frequency is increased significantly in ultrasonic-wave-assisted GMAW (U-GMAW). However, the stability of the metal transfer has deep influence on the welding quality equally, and the ultrasonic wave effect on the stability of the metal transfer is a phenomenon that is not completely understood. In this article, the stabilities of the short-circuiting transfer process and globular transfer process are studied systematically, and the effect of ultrasonic wave on the metal transfer is analyzed further. The transfer frequency and process stability of the U-GMAW process are much higher than those of the conventional GMAW. Analytical results show that the additional ultrasonic wave is helpful for improving welding stability.

  20. Effect of heavy metals on nitrification performance in different activated sludge processes

    International Nuclear Information System (INIS)

    You, Sheng-Jie; Tsai, Yung-Pin; Huang, Ru-Yi

    2009-01-01

    To understand the toxic effect of heavy metals on the nitrification mechanisms of activated sludge, this study identified the specific ammonia utilization rate (SAUR) inhibited by Pb, Ni and/or Cd shock loadings. Seven different heavy metal combinations (Pb, Ni, Cd, Pb + Ni, Ni + Cd, Pb + Cd, and Pb + Ni + Cd) with seven different heavy metal concentrations (0, 2, 5, 10, 15, 25, and 40 ppm, respectively) were examined by batch experiments, where the activated sludge was taken from either sequencing batch reactor (SBR) or anaerobic-anoxic-oxic (A 2 O) processes. The experimental results showed the SAUR inhibition rate was Ni > Cd > Pb. No significant inhibition in the nitrification reaction of the activated sludge was observed even when as much as 40 ppm Pb was added. In addition, no synergistic effect was found when different heavy metals were simultaneously added in different concentrations, and the overall inhibition effect depended on the heavy metal with the highest toxicity. Further, first order kinetic reaction could model the behavior of SAUR inhibition on activated sludge when adding heavy metals, and the SAUR inhibition formula was derived as SAUR=(SAUR max -SAUR min )xe -r i c +SAUR min . On the other hand, the heavy metal adsorption ability in both the activated sludge system was Pb = Cd > Ni. The specific adsorption capacity of activated sludge on heavy metal increased as the heavy metal concentration increased or the mixed liquid volatile suspended solid (MLVSS) decreased. The batch experiments also showed the heavy metal adsorption capacity of the SBR sludge was larger than the A 2 O sludge. Finally, the most predominant bacteria in the phylogenetic trees of SBR and A 2 O activated sludges were proteobacteria, which contributed to 42.1% and 42.8% of the total clones.

  1. Recycling of spent noble metal catalysts with emphasis on pyrometallurgical processing

    Energy Technology Data Exchange (ETDEWEB)

    Hagelueken, C. [Degussa Huels AG, Hanau (Germany)

    1999-09-01

    Precious metal catalysts for catalytic Naphta Reforming, Isomerization, Hydrogenation and other chemical and petrochemical processes are valuable assets for oil refineries and chemical companies. At the end of the service life of a reactor load of catalyst, the efficient and reliable recovery of the precious metals contained in the catalyst is of paramount importance. More than 150 years of technological advances at Degussa-Huels have resulted in refining methods for all kinds of precious metal containing materials which guarantee an optimum technical yield of the precious metals included. The refining of catalysts today is one of the important activities in the precious metals business unit. In the state-of-the-art precious metal refinery at Hanau in the centre of Germany, a wide variety of processes for the recovery of all precious metals is offered. These processes include accurate preparation, sampling and analysis as well as both wet-chemical and pyrometallurgical recovery techniques. Special emphasis in this presentation is laid on the advantages of pyrometallurgical processes for certain kinds of catalysts. To avoid any risks during transport, sampling and treatment of the spent catalyst, all parties involved in the recycling chain strictly have to follow the relevant safety regulations. Under its commitment to 'Responsible Care' standard procedures have been developed which include pre-shipment samples, safety data sheets/questionnaires and inspection of spent catalysts. These measures not only support a safe and environmentally sound catalyst recycling but also enable to determine the most suitable and economic recovery process - for the benefit of the customer. (orig.)

  2. Monitoring of Soil Remediation Process in the Metal Mining Area

    Science.gov (United States)

    Kim, Kyoung-Woong; Ko, Myoung-Soo; Han, Hyeop-jo; Lee, Sang-Ho; Na, So-Young

    2016-04-01

    Stabilization using proper additives is an effective soil remediation technique to reduce As mobility in soil. Several researches have reported that Fe-containing materials such as amorphous Fe-oxides, goethite and hematite were effective in As immobilization and therefore acid mine drainage sludge (AMDS) may be potential material for As immobilization. The AMDS is the by-product from electrochemical treatment of acid mine drainage and mainly contains Fe-oxide. The Chungyang area in Korea is located in the vicinity of the huge abandoned Au-Ag Gubong mine which was closed in the 1970s. Large amounts of mine tailings have been remained without proper treatment and the mobilization of mine tailings can be manly occurred during the summer heavy rainfall season. Soil contamination from this mobilization may become an urgent issue because it can cause the contamination of groundwater and crop plants in sequence. In order to reduce the mobilization of the mine tailings, the pilot scale study of in-situ stabilization using AMDS was applied after the batch and column experiments in the lab. For the monitoring of stabilization process, we used to determine the As concentration in crop plants grown on the field site but it is not easily applicable because of time and cost. Therefore, we may need simple monitoring technique to measure the mobility or leachability which can be comparable with As concentration in crop plants. We compared several extraction methods to suggest the representative single extraction method for the monitoring of soil stabilization efficiency. Several selected extraction methods were examined and Mehlich 3 extraction method using the mixture of NH4F, EDTA, NH4NO3, CH3COOH and HNO3 was selected as the best predictor of the leachability or mobility of As in the soil remediation process.

  3. Effects of different drying processes on the concentrations of metals and metalloids in plant materials

    International Nuclear Information System (INIS)

    Anawar, H.M.; Canha, N.; Freitas, M.C; Santa Regina, I.; Garcia-Sanchez, A.

    2011-01-01

    The drying process of fresh plant materials may affect the porous structure, dehydration and a number of quality characteristics of these materials. Therefore, this study has investigated the effect of different drying processes on the variation of metal and metalloid concentrations in the dried plant materials. Seven varieties of native plant species collected from Sao Domingos mine were analyzed by instrumental neutron activation analysis (INAA) to investigate the effects of freeze-drying (FD), ambient air-drying (AAD) and oven-drying (OD) process on the concentrations of metals and metalloids in the plant biomass. Comparison of ambient air-dried, oven-dried and freeze-dried preparations allows a phenomenological description of the dehydration artefacts. In the quantitative analysis of metals and metalloids, FD and OD plant samples show the higher concentrations of metals and metalloids when compared to those in the AAD plant biomass. The freeze-drying process is comparatively reliable for determination of metals and metalloids concentrations in plant materials. (author)

  4. Environmental Benign Process for Production of Molybdenum Metal from Sulphide Based Minerals

    Science.gov (United States)

    Rajput, Priyanka; Janakiram, Vangada; Jayasankar, Kalidoss; Angadi, Shivakumar; Bhoi, Bhagyadhar; Mukherjee, Partha Sarathi

    2017-10-01

    Molybdenum is a strategic and high temperature refractory metal which is not found in nature in free state, it is predominantly found in earth's crust in the form of MoO3/MoS2. The main disadvantage of the industrial treatment of Mo concentrate is that the process contains many stages and requires very high temperature. Almost in every step many gaseous, liquid, solid chemical substances are formed which require further treatment. To overcome the above drawback, a new alternative one step novel process is developed for the treatment of sulphide and trioxide molybdenum concentrates. This paper presents the results of the investigations on molybdenite dissociation (MoS2) using microwave assisted plasma unit as well as transferred arc thermal plasma torch. It is a single step process for the preparation of pure molybdenum metal from MoS2 by hydrogen reduction in thermal plasma. Process variable such as H2 gas, Ar gas, input current, voltage and time have been examined to prepare molybdenum metal. Molybdenum recovery of the order of 95% was achieved. The XRD results confirm the phases of molybdenum metal and the chemical analysis of the end product indicate the formation of metallic molybdenum (Mo 98%).

  5. A study on the manufacturing conditions of metal matrix composites by low pressure infiltration process

    Energy Technology Data Exchange (ETDEWEB)

    Park, Won Jo; Hessian, Md Anowar; Park, Sung Ho [Gyeongsang National University, Tongyoung (Korea, Republic of); Huh, Sun Chul [Gyeongsang National University, JinJu (Korea, Republic of)

    2007-10-15

    Metal fiber preform reinforced aluminum alloy composite as made by the infiltration of molten metal under low pressure casting process. The infiltration behavior of filling pattern and the velocity profile with low-pressure casting process was investigated. The thermocouple was inserted into the preform in order to observe the infiltration behavior. The infiltration of applied pressure time, 1, 2 and 5 s under constant pressure of 0.4 MPa was completely filled during 0.4 s. In these conditions, molten aluminum alloy has successfully infiltrated to FeCrSi metal fiber preform by low-pressure casting process. It was observed the porosity of composites for reliability of composites. The automobile piston was developed with FeCrSi reinforced aluminum alloy that is 0% porosity by the optimal applied pressure and applied pressure time.

  6. Effects of holding pressure and process temperatures on the mechanical properties of moulded metallic parts

    DEFF Research Database (Denmark)

    Islam, Aminul; Hansen, Hans Nørgaard; Esteves, N.M.

    2013-01-01

    Metal injection moulding is gaining more and more importance over the time and needs more research to be done to understand the sensitivity of process to different process parameters. The current paper makes an attempt to better understand the effects of holding pressure and process temperatures...... on the moulded metallic parts. Stainless steel 316L is used in the investigation to produce the specimen by metal injection moulding (MIM) and multiple analyses were carried out on samples produced with different combinations of holding pressure, mould temperature and melt temperature. Finally, the parts were...... characterized to investigate mechanical properties like density, ultimate tensile strength, shrinkage etc. The results are discussed in the paper. The main conclusion from this study is unlike plastic moulding, the tensile properties of MIM parts doesn’t vary based on the flow direction of the melt, and tensile...

  7. Feasibility Study on Flexibly Reconfigurable Roll Forming Process for Sheet Metal and Its Implementation

    Directory of Open Access Journals (Sweden)

    Jun-Seok Yoon

    2014-06-01

    Full Text Available A multicurved sheet metal surface for a skin structure has usually been manufactured using a conventional die forming process involving the use of both a die and a press machine in accordance with the product shape. However, such processes are economically inefficient because additional production costs are incurred for the development and management of forming tools. To overcome this drawback, many alternative processes have been developed; however, these still suffer from problems due to defects such as dimples and wrinkles occurring in the sheet. In this study, a new sheet metal forming process called the flexibly reconfigurable roll forming (FRRF process is proposed as an alternative to existing processes. Unlike existing processes, FRRF can reduce additional production costs resulting from material loss and significantly reduce forming errors. Furthermore, it involves the use of a smaller apparatus. The methodology and applicable procedure of the FRRF process are described. Numerical forming simulations of representative multicurved sheet surfaces are conducted using FEM. In addition, a simple apparatus is developed for verifying the feasibility of this process, and a doubly curved metal is formed to verify the applicability of the reconfigurable roller, a critical component in this forming process.

  8. Reduction of Surface Roughness by Means of Laser Processing over Additive Manufacturing Metal Parts.

    Science.gov (United States)

    Alfieri, Vittorio; Argenio, Paolo; Caiazzo, Fabrizia; Sergi, Vincenzo

    2016-12-31

    Optimization of processing parameters and exposure strategies is usually performed in additive manufacturing to set up the process; nevertheless, standards for roughness may not be evenly matched on a single complex part, since surface features depend on the building direction of the part. This paper aims to evaluate post processing treating via laser surface modification by means of scanning optics and beam wobbling to process metal parts resulting from selective laser melting of stainless steel in order to improve surface topography. The results are discussed in terms of roughness, geometry of the fusion zone in the cross-section, microstructural modification, and microhardness so as to assess the effects of laser post processing. The benefits of beam wobbling over linear scanning processing are shown, as heat effects in the base metal are proven to be lower.

  9. A REVIEW ON HEAVY METALS CONTENTS IN HIDE, SKIN AND PROCESSED LEATHERS

    Directory of Open Access Journals (Sweden)

    KOIZHAIGANOVA Meruyert

    2016-05-01

    Full Text Available Heavy metals are metals with high atomic weight which can be deposited in soil, water, plants and animals. It is generally known that mammal tissues are good bioindicators of trace elements, including heavy metals. Heavy metal analysis serves to identify and quantify the elements that are a potential hazard to the consumer after varying levels of contact. Usage area of leather is increasingly expanding in these days and it has also become a material requested and demanded by effect of fashion. Leather must protect its appearance and physical stability and also be problem-free in ecological terms and harmless to human health. There is a lack of data concerning the content of toxic elements in raw hide and skin of animals. Mainly information concerning metals content, including toxic ones, in processed leathers may be found in the literature. The aim of the present study was to review and compare the content of some heavy metals in raw hide, skin and the processed leathers in order to evaluate their accumulation and transition to the end-up product.

  10. Decontamination processes for low level radioactive waste metal objects

    International Nuclear Information System (INIS)

    Longnecker, E.F.; Ichikawa, Sekigo; Kanamori, Osamu

    1996-01-01

    Disposal and safe storage of contaminated nuclear waste is a problem of international scope. Although the greatest volume of such waste is concentrated in the USA and former Soviet Union, Western Europe and Japan have contaminated nuclear waste requiring attention. Japan's radioactive nuclear waste is principally generated at nuclear power plants since it has no nuclear weapons production. However, their waste reduction, storage and disposal problems may be comparable to that of the USA on an inhabited area basis when consideration is given to population density where Japan's population, half that of the USA, lives in an area slightly smaller than that of California's. If everyone's backyard was in California, the USA might have insoluble radioactive waste reduction, storage and disposal problems. Viewing Japan's contaminated nuclear waste as a national problem requiring solutions, as well as an economic opportunity, Morikawa began research and development for decontaminating low level radioactive nuclear waste seven years ago. As engineers and manufacturers of special machinery for many years Morikawa brings special electro/mechanical/pneumatic Skills and knowledge to solving these unique problems. Genden Engineering Services and Construction Company (GESC), an affiliate of Japan Atomic Power Company, recently joined with Morikawa in this R ampersand D effort to decontaminate low level radioactive nuclear waste (LLW) and to substantially reduce the volume of such nuclear waste requiring long term storage. This paper will present equipment with both mechanical and chemical processes developed over these several years by Morikawa and most recently in cooperation with GESC

  11. The process of biosorption of heavy metals in bioreactors loaded with sanitary sewage sludge

    Directory of Open Access Journals (Sweden)

    A. J. Morais Barros

    2006-06-01

    Full Text Available This work on the process of biosorption of nickel and chromium in an ascendant continuous-flow, fixed packed-bed bioreactor of sanitary sewage sludge was conducted in a search for solutions to the environmental problem caused by heavy metals. Analysis of the results demonstrated that the absorbent had an extraordinary capacity for biosorption of the heavy metals studied at about 9.0 pH of the effluent, with a removal percentage of over 90.0% for the two metals. Chemometric study results demonstrated that 20 days of the experimental system function were sufficient for achieving the maximum efficiency of sorption of the heavy metals studied by the sanitary sewage sludge employed.

  12. Induction skull melting facility: an advanced system for electromagnetic processing of metals and alloys

    International Nuclear Information System (INIS)

    Sugilal, G.; Agarwal, K.

    2017-01-01

    Induction Skull Melting (ISM) is an advanced technology for processing highly refractory and extremely reactive metals and their alloys to produce ultra-high purity products. In ISM, the metallic charge is melted in a water-cooled, copper crucible. The crucible is segmented so that the magnetic field can penetrate into the metallic charge to be melted. By virtue of the strong electromagnetic stirring, the ISM technology can also be used to homogenize alloys of metals, which are difficult to be combined uniformly in composition due to large difference in specific gravity. In view of various important applications in frontier areas of material research, development and production, Bhabha Atomic Research Centre developed the ISM technology indigenously

  13. Preface to the Viewpoint Set: Nanostructured metals - Advances in processing, characterization and application

    DEFF Research Database (Denmark)

    Huang, Xiaoxu

    2009-01-01

    with increasingly finer structures in order to improve properties and sustainability. The structural scale of interest in such materials is therefore reduced to the nanometer range, which means that characterization and modeling of nanostructured metals now address an audience including not only physicists...... and materials scientists but also technologists and engineers. The present Viewpoint Set therefore covers metallic materials with a structural scale ranging from micrometer to nanometer in dimensions and focuses on processing techniques such as plastic deformation and phase transformations. As a result......The theme of two viewpoint sets has been nanostructured metals: one in 2003 on “Mechanical properties of fully dense nanocrystalline metals” (Scripta Materialia 2003;49:625–680) and one in 2004 on “Metals and alloys with a structural scale from the micrometer to the atomic dimensions” (Scripta...

  14. 3-D Modelling of Electromagnetic, Thermal, Mechanical and Metallurgical Couplings in Metal Forming Processes

    International Nuclear Information System (INIS)

    Chenot, Jean-Loup; Bay, Francois

    2007-01-01

    The different stages of metal forming processes often involve - beyond the mechanical deformations processes - other physical coupled problems, such as heat transfer, electromagnetism or metallurgy. The purpose of this paper is to focus on problems involving electromagnetic couplings. After a brief recall on electromagnetic modeling, we shall then focus on induction heating processes and present some results regarding heat transfer, as well as mechanical couplings. A case showing coupling for metallurgic microstructure evolution will conclude this paper

  15. Trends And Economic Assessment Of Integration Processes At The Metal Market

    OpenAIRE

    Olga Aleksandrovna Romanova; Eduard Vyacheslavovich Makarov

    2015-01-01

    The article discussed the integration process from the perspective of three dimensions that characterize the corresponding increase in the number and appearance of new relationships; strength, character, and stability of emerging communications; dynamics and the appropriate form of the process. In the article, trends of development of integration processes in metallurgy are identified, identification of five stages of development in Russian metal trading are justified. We propose a s...

  16. Considerations of metal joining processes for space fabrication, construction and repair

    Science.gov (United States)

    Russell, C.; Poorman, R.; Jones, C.; Nunes, A.; Hoffman, D.

    1991-01-01

    A comprehensive evaluation is conducted of candidate processes for metalworking in orbital (vacuum-microgravity) conditions. Attention is given to electron-beam welding, brazing, gas-tungsten arc welding, laser welding, plasma arc welding, and gas-metal arc welding. It is established that several of these processes will be required to cover all foreseeable requirements. Microgravity effects are considered minor, and efforts are being concentrated on problems associated with vacuum conditions and with process-operator safety.

  17. Decontamination of alpha contaminated metallic waste by cerium IV redox process

    International Nuclear Information System (INIS)

    Shah, J.G.; Dhami, P.S.; Gandhi, P.M.; Wattal, P.K.

    2012-01-01

    Decontamination of alpha contaminated metallic waste is an important aspect in the management of waste generated during dismantling and decommissioning of nuclear facilities. Present work on cerium redox process targets decontamination of alpha contaminated metallic waste till it qualifies for the non alpha waste category for disposal in near surface disposal facility. Recovery of the alpha radio nuclides and cerium from aqueous secondary waste streams was also studied deploying solvent extraction process and established. The alpha-lean secondary waste stream has been immobilised in cement based matrix for final disposal. (author)

  18. Plasma assisted measurements of alkali metal concentrations in pressurized combustion processes

    International Nuclear Information System (INIS)

    Hernberg, R.; Haeyrinen, V.

    1995-01-01

    The plasma assisted method for continuous measurement of alkali metal concentrations in product gas flows of pressurized energy processes will be tested and applied at the 1.6 MW PFBC/G facility at Delft University of Technology in the Netherlands. Measurements will be performed during 1995 and 1996 at different stages of the research programme. The results are expected to give information about the influence of different process conditions on the generation of alkali metal vapours, the comparison of different methods for alkali measurement and the specific performance of our system. The project belongs to the Joule II extension program under contract JOU2-CT93-0431. (author)

  19. The effect of additives on release and in vitro skin retention of flavonoids from emulsion and gel semisolid formulations.

    Science.gov (United States)

    Dyja, R; Jankowski, A

    2017-08-01

    To assess the effect of two different additives (propylene glycol (PG) and polyethylene glycol 400 (PEG 400)) on release and in vitro skin retention of quercetin and chrysin from semisolid bases (amphiphilic creams and acidic carbomer gels). For obtaining semisolid formulations, flavonoids were pre-dissolved in the liquid (PG or PEG 400) or directly suspended in the semisolid base. Three chrysin formulations ('cream 0', 'PG-cream' and 'PEG 400-cream') and five quercetin formulations ('cream 0', 'PG cream', 'PEG 400 cream', 'gel 0' and 'PG gel') were prepared. The release studies were carried out in Franz diffusion cells by means of a cellulose membrane. The porcine ear skin was used in in vitro skin retention studies. The dissolution was a prerequisite to increase the release rates of tested flavonoids from obtained semisolid formulations. The cumulative amount of chrysin released after 6 h from 'PEG 400 cream' containing partly dissolved form of that flavonoid was higher than that from 'cream 0' or 'PG cream' containing its suspended form. The formulations containing quercetin dissolved in PG ('PG cream', 'PG gel') or PEG 400 ('PEG 400 cream') exhibited higher release rates of that flavonoid than corresponding semisolid suspensions ('cream 0' or 'gel 0'). The effects of both liquid additives (PG and PEG 400) on the cumulative amount of quercetin released after 6 h were comparable. However, there was no correlation between the release rate and the skin retention. The amounts of the flavonoids found in the skin were strongly affected by the type of the used solvent. While PG increased the skin retention of both flavonoids, PEG 400 had no effect on chrysin skin retention and delayed quercetin skin absorption. The proper choice of the solvent added to the semisolid base is crucial for enhanced skin delivery of the tested flavonoids. PG is more efficient absorption promoter than PEG 400 of both chrysin and quercetin. © 2017 Society of Cosmetic Scientists and the Soci

  20. Bio-processing of solid wastes and secondary resources for metal extraction - A review.

    Science.gov (United States)

    Lee, Jae-Chun; Pandey, Banshi Dhar

    2012-01-01

    Metal containing wastes/byproducts of various industries, used consumer goods, and municipal waste are potential pollutants, if not treated properly. They may also be important secondary resources if processed in eco-friendly manner for secured supply of contained metals/materials. Bio-extraction of metals from such resources with microbes such as bacteria, fungi and archaea is being increasingly explored to meet the twin objectives of resource recycling and pollution mitigation. This review focuses on the bio-processing of solid wastes/byproducts of metallurgical and manufacturing industries, chemical/petrochemical plants, electroplating and tanning units, besides sewage sludge and fly ash of municipal incinerators, electronic wastes (e-wastes/PCBs), used batteries, etc. An assessment has been made to quantify the wastes generated and its compositions, microbes used, metal leaching efficiency etc. Processing of certain effluents and wastewaters comprising of metals is also included in brief. Future directions of research are highlighted. Copyright © 2011 Elsevier Ltd. All rights reserved.

  1. Metal adsorption process in activated carbon fiber from textile PAN fiber aim electrode production

    International Nuclear Information System (INIS)

    Rodrigues, Aline Castilho; Goncalves, Emerson Sarmento; Silva, Elen Leal da; Marcuzzo, Jossano Saldanha; Baldan, Mauricio Ribeiro; Cuna, Andres

    2016-01-01

    Full text: Carbon fibers have a variety of applications in industry and have been increasingly studied to explore their various characteristics. Studies show that the activated carbon fiber has been effective in removing small contaminants as well as activated carbon, because of its characteristic porosity. Other studies relate carbonaceous materials to the electrical conductivity devices application. This work is based on the use of an activated carbon fiber from textile polyacrylonitrile (PAN) for metallic ion adsorption from aqueous solution. Consequently, it improves the electrical characteristics and this fact show the possibility to use this material as electrode. The work was performed by adsorption process in saline solution (NO 3 Ag and ClPd) and activated carbon fiber in felt form as adsorbent. The metal adsorption on activated carbon fiber was characterized by textural analysis, x-ray diffraction (XRD), scanning electron microscopy equipped with energy dispersive x-ray (SEM-EDX), Raman spectroscopy and x-ray photoelectron spectroscopy (XPS). It was observed that activated carbon fiber showed good adsorption capacity for the metals used. At the end of the process, the activated carbon fiber samples gained about 15% by weight, related to metallic fraction incorporated into the fiber and the process of adsorption does not changed the structural, morphological and chemistry inertness of the samples. The results indicate the feasibility of this metal incorporation techniques activated carbon fiber for the production of electrodes facing the electrochemical area. (author)

  2. Metal adsorption process in activated carbon fiber from textile PAN fiber aim electrode production

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, Aline Castilho; Goncalves, Emerson Sarmento, E-mail: alinerodrigues_1@msn.com [Instituto Tecnologico Aeroespacial (ITA), Sao Jose dos Campos, SP (Brazil); Silva, Elen Leal da; Marcuzzo, Jossano Saldanha; Baldan, Mauricio Ribeiro [Instituto Nacional de Pesquisas Espaciais (INPE), Sao Jose dos Campos, SP (Brazil); Cuna, Andres [Faculdade de Quimica, Universidad de la Republica (Uruguay)

    2016-07-01

    Full text: Carbon fibers have a variety of applications in industry and have been increasingly studied to explore their various characteristics. Studies show that the activated carbon fiber has been effective in removing small contaminants as well as activated carbon, because of its characteristic porosity. Other studies relate carbonaceous materials to the electrical conductivity devices application. This work is based on the use of an activated carbon fiber from textile polyacrylonitrile (PAN) for metallic ion adsorption from aqueous solution. Consequently, it improves the electrical characteristics and this fact show the possibility to use this material as electrode. The work was performed by adsorption process in saline solution (NO{sub 3}Ag and ClPd) and activated carbon fiber in felt form as adsorbent. The metal adsorption on activated carbon fiber was characterized by textural analysis, x-ray diffraction (XRD), scanning electron microscopy equipped with energy dispersive x-ray (SEM-EDX), Raman spectroscopy and x-ray photoelectron spectroscopy (XPS). It was observed that activated carbon fiber showed good adsorption capacity for the metals used. At the end of the process, the activated carbon fiber samples gained about 15% by weight, related to metallic fraction incorporated into the fiber and the process of adsorption does not changed the structural, morphological and chemistry inertness of the samples. The results indicate the feasibility of this metal incorporation techniques activated carbon fiber for the production of electrodes facing the electrochemical area. (author)

  3. The impact of metal transport processes on bioavailability of free and complex metal ions in methanogenic granular sludge

    NARCIS (Netherlands)

    Bartacek, J.; Fermoso, F.G.; Vergeldt, F.; Gerkema, E.; Maca, J.; As, van H.; Lens, P.N.L.

    2012-01-01

    Bioavailability of metals in anaerobic granular sludge has been extensively studied, because it can have a major effect on metal limitation and metal toxicity to microorganisms present in the sludge. Bioavailability of metals can be manipulated by bonding to complexing molecules such as

  4. SINTERING, A PROCESS OF METAL FORMING AS AN ECONOMIC ALTERNATIVE WITH A LOW ENVIRONMENTAL IMPACT

    Directory of Open Access Journals (Sweden)

    Ángel Silvio Machado Rodríguez

    2017-07-01

    Full Text Available Sintering is a process of metal forming using metal powders, and it has a wide range of applications including for example, the manufacturing of parts for automotive components, home appliances, cutting tools, power tools, for the manufacturing of dental devices, among others. The process is characterized by the production of large-scale low cost parts and has a low environmental impact compared to other existing technologies, it requires less energy for processing and enables high utilization of raw materials. Also, it has the characteristic of obtaining, in most cases, the parts with final tolerances necessary for direct use by the customer, which ultimately reduces considerably the cost of production. The process is characterized by minimizing the loss of raw materials; facilitating precise control of the desired chemical composition; eliminating or reducing machining operations; providing a good surface finish; being an easy production process of automation; obtaining high purity; and ensuring exactly resistance characteristics required for each project.

  5. Fabrication of metal-matrix composites and adaptive composites using ultrasonic consolidation process

    International Nuclear Information System (INIS)

    Kong, C.Y.; Soar, R.C.

    2005-01-01

    Ultrasonic consolidation (UC) has been used to embed thermally sensitive and damage intolerant fibres within aluminium matrix structures using high frequency, low amplitude, mechanical vibrations. The UC process can induce plastic flow in the metal foils being bonded, to allow the embedding of fibres at typically 25% of the melting temperature of the base metal and at a fraction of the clamping force when compared to fusion processes. To date, the UC process has successfully embedded Sigma silicon carbide (SiC) fibres, shape memory alloy wires and optical fibres, which are presented in this paper. The eventual aim of this research is targeted at the fabrication of adaptive composite structures having the ability to measure external stimuli and respond by adapting their structure accordingly, through the action of embedded active and passive functional fibres within a freeform fabricated metal-matrix structure. This paper presents the fundamental studies of this research to identify embedding methods and working range for the fabrication of adaptive composite structures. The methods considered have produced embedded fibre specimens in which large amounts of plastic flow have been observed, within the matrix, as it is deformed around the fibres, resulting in fully consolidated specimens without damage to the fibres. The microscopic observation techniques and macroscopic functionality tests confirms that the UC process could be applied to the fabrication of metal-matrix composites and adaptive composites, where fusion techniques are not feasible and where a 'cold' process is necessary

  6. Metals Processing Laboratory Users (MPLUS) Facility Annual Report FY 2002 (October 1, 2001-September 30, 2002)

    Energy Technology Data Exchange (ETDEWEB)

    Angelini, P

    2004-04-27

    The Metals Processing Laboratory Users Facility (MPLUS) is a Department of Energy (DOE), Energy Efficiency and Renewable Energy, Industrial Technologies Program, user facility designated to assist researchers in key industries, universities, and federal laboratories in improving energy efficiency, improving environmental aspects, and increasing competitiveness. The goal of MPLUS is to provide access to the specialized technical expertise and equipment needed to solve metals processing issues that limit the development and implementation of emerging metals processing technologies. The scope of work can also extend to other types of materials. MPLUS has four primary user centers: (1) Processing--casting, powder metallurgy, deformation processing (including extrusion, forging, rolling), melting, thermomechanical processing, and high-density infrared processing; (2) Joining--welding, monitoring and control, solidification, brazing, and bonding; (3) Characterization--corrosion, mechanical properties, fracture mechanics, microstructure, nondestructive examination, computer-controlled dilatometry, and emissivity; and (4) Materials/Process Modeling--mathematical design and analyses, high-performance computing, process modeling, solidification/deformation, microstructure evolution, thermodynamic and kinetic, and materials databases A fully integrated approach provides researchers with unique opportunities to address technologically related issues to solve metals processing problems and probe new technologies. Access is also available to 16 additional Oak Ridge National Laboratory (ORNL) user facilities ranging from state-of-the-art materials characterization capabilities, and high-performance computing to manufacturing technologies. MPLUS can be accessed through a standardized user-submitted proposal and a user agreement. Nonproprietary (open) or proprietary proposals can be submitted. For open research and development, access to capabilities is provided free of charge

  7. Metals Processing Laboratory Users (MPLUS) Facility Annual Report: October 1, 2000 through September 30, 2001

    Energy Technology Data Exchange (ETDEWEB)

    Angelini, P

    2004-04-27

    The Metals Processing Laboratory Users Facility (MPLUS) is a Department of Energy (DOE), Energy Efficiency and Renewable Energy, Industrial Technologies Program user facility designated to assist researchers in key industries, universities, and federal laboratories in improving energy efficiency, improving environmental aspects, and increasing competitiveness. The goal of MPLUS is to provide access to the specialized technical expertise and equipment needed to solve metals processing issues that limit the development and implementation of emerging metals processing technologies. The scope of work can also extend to other types of materials. MPLUS has four primary User Centers including: (1) Processing--casting, powder metallurgy, deformation processing including (extrusion, forging, rolling), melting, thermomechanical processing, high density infrared processing; (2) Joining--welding, monitoring and control, solidification, brazing, bonding; (3) Characterization--corrosion, mechanical properties, fracture mechanics, microstructure, nondestructive examination, computer-controlled dilatometry, and emissivity; (4) Materials/Process Modeling--mathematical design and analyses, high performance computing, process modeling, solidification/deformation, microstructure evolution, thermodynamic and kinetic, and materials data bases. A fully integrated approach provides researchers with unique opportunities to address technologically related issues to solve metals processing problems and probe new technologies. Access is also available to 16 additional Oak Ridge National Laboratory (ORNL) user facilities ranging from state of the art materials characterization capabilities, high performance computing, to manufacturing technologies. MPLUS can be accessed through a standardized User-submitted Proposal and a User Agreement. Nonproprietary (open) or proprietary proposals can be submitted. For open research and development, access to capabilities is provides free of charge while

  8. Springback prediction in sheet metal forming process based on the hybrid SA

    International Nuclear Information System (INIS)

    Guo Yuqin; Jiang Hong; Wang Xiaochun; Li Fuzhu

    2005-01-01

    In terms of the intensive similarity between the sheet metal forming-springback process and that of the annealing of metals, it is suggested that the simulation of the sheet metal forming process is performed with the Nonlinear FEM and the springback prediction is implemented by solving the large-scale combinational optimum problem established on the base of the energy descending and balancing in deformed part. The BFGS-SA hybrid SA approach is proposed to solve this problem and improve the computing efficiency of the traditional SA and its capability of obtaining the global optimum solution. At the same time, the correlative annealing strategies for the SA algorithm are determined in here. By comparing the calculation results of sample part with those of experiment measurement at the specified sections, the rationality of the schedule of springback prediction used and the validity of the BFGS-SA algorithm proposed are verified

  9. Trace metal pyritization variability in response to mangrove soil aerobic and anaerobic oxidation processes.

    Science.gov (United States)

    Machado, W; Borrelli, N L; Ferreira, T O; Marques, A G B; Osterrieth, M; Guizan, C

    2014-02-15

    The degree of iron pyritization (DOP) and degree of trace metal pyritization (DTMP) were evaluated in mangrove soil profiles from an estuarine area located in Rio de Janeiro (SE Brazil). The soil pH was negatively correlated with redox potential (Eh) and positively correlated with DOP and DTMP of some elements (Mn, Cu and Pb), suggesting that pyrite oxidation generated acidity and can affect the importance of pyrite as a trace metal-binding phase, mainly in response to spatial variability in tidal flooding. Besides these aerobic oxidation effects, results from a sequential extraction analyses of reactive phases evidenced that Mn oxidized phase consumption in reaction with pyrite can be also important to determine the pyritization of trace elements. Cumulative effects of these aerobic and anaerobic oxidation processes were evidenced as factors affecting the capacity of mangrove soils to act as a sink for trace metals through pyritization processes. Copyright © 2013 Elsevier Ltd. All rights reserved.

  10. Pseudomacrocyclic effect in extraction processes of metal salts by polyethers from nitric acid solutions

    International Nuclear Information System (INIS)

    Yakshin, V.V.; Vilkova, O.M.; Kotlyar, S.A.; Kamalov, G.L.

    1997-01-01

    Comparison of macrocyclic (ME) and pseudmacrocyclic effects (PME), originating by conduct of the metal salt extraction processes (Cs, Sr, In, Zr, Cd, etc) from nitric acid solutions through linear and cyclic polyethers, containing 5 or 6 atoms of ether oxygen and having close molecular masses (290-360), is carried out. It is shown that ordinary ethers practically do not extract the studied metals from nitric acid solutions. By transfer from linear polyethers to their macrocyclic analogs the ME impact is expressed clearly enough: the separation coefficient value grows by tens and hundred times. At the some time the PME role in the extraction processes of metal nitrates through crown-ethers with alkyl and groups is expressed less clearly

  11. Characteristics of diffusion zone in changing glass-metal composite processing conditions

    Science.gov (United States)

    Lyubimova, O. N.; Morkovin, A. V.; Andreev, V. V.

    2018-03-01

    The influence of manufacturing technology on the characteristics of the glass and steel contact zone in manufacturing new structural material - glass-metal composite is studied theoretically and experimentally. Different types of structures in the contact zone and its dimensions affect the strength characteristics of the composite. Knowledge about changing the width of the glass and steel contact zone after changing such parameters of the technological regime as temperature, holding time and use of solders will allow one to control the structure and characteristics of the glass-metal composite. Experimental measurements of the width of the diffusion zone in the glass-metal composite for different regimes and their statistical processing according to the full factor experiment are presented in this article. The results of analysis of some mechanical characteristics of the diffusion zone are presented: microhardness and modulus of elasticity for samples, prepared according to different processing regimes.

  12. Development of a new process for deposition of metallic vapours and ions

    International Nuclear Information System (INIS)

    Gabrielli, O. de.

    1989-01-01

    Surface treatment processes by deposition, enabling surface properties to be altered without altering the volume, are making rapid progress in industry. The description of these processes has led us to consider the role and the importance of methods using plasmas. The new plasma source we have developed is the subject of this experimental research: it is the basis of the deposition process (metallic ion and vapour deposition). The specifications and preliminary results enable us to compare this process with others in use. Fast deposition rates and excellent adhesion are the two main characteristics of this process [fr

  13. System and process for production of magnesium metal and magnesium hydride from magnesium-containing salts and brines

    Science.gov (United States)

    McGrail, Peter B.; Nune, Satish K.; Motkuri, Radha K.; Glezakou, Vassiliki-Alexandra; Koech, Phillip K.; Adint, Tyler T.; Fifield, Leonard S.; Fernandez, Carlos A.; Liu, Jian

    2016-11-22

    A system and process are disclosed for production of consolidated magnesium metal products and alloys with selected densities from magnesium-containing salts and feedstocks. The system and process employ a dialkyl magnesium compound that decomposes to produce the Mg metal product. Energy requirements and production costs are lower than for conventional processing.

  14. Mechanical behavior and microstructure during compression of semi-solid ZK60-RE magnesium alloy at high solid content

    International Nuclear Information System (INIS)

    Shan Weiwei; Luo Shoujing

    2007-01-01

    Mechanical behavior during compression of semi-solid ZK60-RE magnesium alloy at high solid content is researched in this paper. The alloy was prepared from ZK60 alloy and rare earth elements by casting, equal channel angular extruding, and liquidus forging. Semi-solid isothermal pre-treatment was carried out to make the grains globular before the compression. Here, several groups of true strain-true stress curves with different variables during compression are given to make comparisons of their mechanical behaviors. Liquid paths were the most essential to deformation, and its variation during compression depends on the strain rate. Here, thixotropic strength is defined as the true stress at the first peak in the true stress-true strain curve

  15. Wear study of Al-SiC metal matrix composites processed through microwave energy

    Science.gov (United States)

    Honnaiah, C.; Srinath, M. S.; Prasad, S. L. Ajit

    2018-04-01

    Particulate reinforced metal matrix composites are finding wider acceptance in many industrial applications due to their isotropic properties and ease of manufacture. Uniform distribution of reinforcement particulates and good bonding between matrix and reinforcement phases are essential features in order to obtain metal matrix composites with improved properties. Conventional powder metallurgy technique can successfully overcome the limitation of stir casting techniques, but it is time consuming and not cost effective. Use of microwave technology for processing particulate reinforced metal matrix composites through powder metallurgy technique is being increasingly explored in recent times because of its cost effectiveness and speed of processing. The present work is an attempt to process Al-SiC metal matrix composites using microwaves irradiated at 2.45 GHz frequency and 900 W power for 10 minutes. Further, dry sliding wear studies were conducted at different loads at constant velocity of 2 m/s for various sliding distances using pin-on-disc equipment. Analysis of the obtained results show that the microwave processed Al-SiC composite material shows around 34 % of resistance to wear than the aluminium alloy.

  16. Workplace Basic Skills in the Metal Casting Industry for World Class Process and Technology.

    Science.gov (United States)

    Rasmussen, Bonnie

    A workplace basic skills project for the metal casting industry was established jointly by Central Alabama Community College and Robinson Foundry, Inc. Evaluation of the project was made through a commercial test of hourly workers' general literacy level gains, instructor-developed pre- and posttests of mastery of the industrial process and…

  17. Static friction in rubber-metal contacts with application to rubber pad forming processes

    NARCIS (Netherlands)

    Deladi, E.L.

    2006-01-01

    A static friction model suitable for rubber-metal contact is presented in this dissertation. In introduction, the motivation and the aims of the research are introduced together with the background regarding the related industrial application, which is the rubber pad forming process.

  18. Heavy metals in soil at a waste electrical and electronic equipment processing area in China.

    Science.gov (United States)

    Gu, Weihua; Bai, Jianfeng; Yao, Haiyan; Zhao, Jing; Zhuang, Xuning; Huang, Qing; Zhang, Chenglong; Wang, JingWei

    2017-11-01

    For the objective of evaluating the contamination degree of heavy metals and analysing its variation trend in soil at a waste electrical and electronic equipment processing area in Shanghai, China, evaluation methods, which include single factor index method, geo-accumulation index method, comprehensive pollution index method, and potential ecological risk index method, were adopted in this study. The results revealed that the soil at a waste electrical and electronic equipment processing area was polluted by arsenic, cadmium, copper, lead, zinc, and chromium. It also demonstrated that the concentrations of heavy metals were increased over time. Exceptionally, the average value of the metalloid (arsenic) was 73.31 mg kg -1 in 2014, while it was 58.31 mg kg -1 in the first half of 2015, and it was 2.93 times and 2.33 times higher than that of the Chinese Environmental Quality Standard for Soil in 2014 and the first half of 2015, respectively. The sequences of the contamination degree of heavy metals in 2014 and the first half of 2015 were cadmium > lead > copper > chromium > zinc and cadmium > lead > chromium > zinc > copper. From the analysis of the potential ecological risk index method, arsenic and cadmium had higher ecological risk than other heavy metals. The integrated ecological risk index of heavy metals (cadmium, copper, lead, zinc, and chromium) and metalloid (arsenic) was 394.10 in 2014, while it was 656.16 in the first half of 2015, thus documenting a strong ecological risk.

  19. Determination of uranium and plutonium in metal conversion products from electrolytic reduction process

    International Nuclear Information System (INIS)

    Lee, Chang Heon; Suh, Moo Yul; Joe, Kih Soo; Sohn, Se Chul; Jee, Kwang Young; Kim, Won Ho

    2005-01-01

    Chemical characterization of process materials is required for the optimization of an electrolytic reduction process in which uranium dioxide, a matrix of spent PWR fuels, is electrolytically reduced to uranium metal in a medium of LiCl-Li 2 O molten at 650 .deg. C. A study on the determination of fissile materials in the uranium metal products containing corrosion products, fission products and residual process materials has been performed by controlled-potential coulometric titration which is well known in the field of nuclear science and technology. Interference of Fe, Ni, Cr and Mg (corrosion products), Nd (fission product) and LiCl molten salt (residual process material) on the determination of uranium and plutonium, and the necessity of plutonium separation prior to the titration are discussed in detail. Under the analytical condition established already, their recovery yields are evaluated along with analytical reliability

  20. Formation of metal and dielectric liners using a solution process for deep trench capacitors.

    Science.gov (United States)

    Ham, Yong-Hyun; Kim, Dong-Pyo; Baek, Kyu-Ha; Park, Kun-Sik; Kim, Moonkeun; Kwon, Kwang-Ho; Shin, Hong-Sik; Lee, Kijun; Do, Lee-Mi

    2012-07-01

    We demonstrated the feasibility of metal and dielectric liners using a solution process for deep trench capacitor application. The deep Si trench via with size of 10.3 microm and depth of 71 microm were fabricated by Bosch process in deep reactive ion etch (DRIE) system. The aspect ratio was about 7. Then, nano-Ag ink and poly(4-vinylphenol) (PVPh) were used to form metal and dielectric liners, respectively. The thicknesses of the Ag and PVPh liners were about 144 and 830 nm, respectively. When the curing temperature of Ag film increased from 120 to 150 degrees C, the sheet resistance decreased rapidly from 2.47 to 0.72 Omega/sq and then slightly decreased to 0.6 Omega/sq with further increasing the curing temperature beyond 150 degrees C. The proposed liner formation method using solution process is a simple and cost effective process for the high capacity of deep trench capacitor.

  1. Universal gas metal arc welding - a cost-effective and low dilution surfacing process

    International Nuclear Information System (INIS)

    Shahi, AS.; Pandey, Sunil

    2006-01-01

    This paper describes the use of a new variant of the gas metal arc welding (GMAW) process, termed u niversal gas metal arc welding (UGMAW), for the weld cladding of low carbon steels with stainless steel. The experimental work included single layer cladding of 12 mm thick low carbon steel with austenitic stainless steel 316L solid filler wire of 1.14 mm diameter. Low dilution conditions were employed using both mechanised GMAW and UGMAW processes. Metallurgical aspects of the as welded overlays were studied to evaluate the suitability of these processes for service conditions. It was found that UGMAW claddings contained higher ferrite content; higher concentrations of chromium, nickel and molybdenum; and lower carbon content compared to GMAW claddings. As a result, the UGMAW overlays exhibited superior mechanical and corrosion resistance properties. The findings of this study establish that the new process is technically superior and results in higher productivity, justifying its use for low cost surfacing applications

  2. Combinational approach using solid dispersion and semi-solid matrix technology to enhance in vitro dissolution of telmisartan

    Directory of Open Access Journals (Sweden)

    Syed Faisal Ali

    2016-02-01

    Full Text Available The present investigation was focused to formulate semi-solid capsules (SSCs of hydrophobic drug telmisartan (TLMS by encapsulating semi-solid matrix of its solid dispersion (SD in HPMC capsules. The combinational approach was used to reduce the lag time in drug release and improvise its dissolution. SDs of TLMS was prepared using hot fusion method by varying the combinations of Pluronic-F68, Gelucire 50/13 and Plasdone S630. A total of nine batches (SD1-SD9 were characterized for micromeritic properties, in vitro dissolution behavior and surface characterization. SD4 with 52.43% cumulative drug release (CDR in phosphate buffer, pH 7.4, in 120 min, t50% 44.2 min and DE30min 96.76% was selected for the development of semi-solid capsules. Differential scanning calorimetry of SD4 revealed molecular dispersion of TLMS in Pluronic-F68. SD4 was formulated into SSCs using Gelucire 44/14 and PEG 400 as semi-solid components and PEG 6000 as a suspending agent to achieve reduction in lag time for effective drug dissolution. SSC6 showed maximum in vitro drug dissolution 97.49 % in phosphate buffer, pH 7.4 with in 20 min that was almost a three folds reduction in the time required to achieve similar dissolution by SD. Thus, SSCs present an excellent approach to enhance in vitro dissolution as well as to reduce the lag time of dissolution for poorly water soluble drugs especially to those therapeutic classes that are intended for faster onset of action. Developed approach based on HPMC capsules provided a better alternative to target delivery of telmisartan to the vegetarian population.

  3. Determination of drug content in semisolid formulations by non-invasive spectroscopic methods: FTIR - ATR, - PAS, - Raman and PDS

    International Nuclear Information System (INIS)

    Gotter, B; Hein, J; Neubert, R H H; Faubel, W; Heissler, St

    2010-01-01

    This study elucidates the potential use of photothermal deflection spectroscopy (PDS), FTIR photoacoustic (FTIR-PAS), FT Raman, and FTIR-attenuated total reflection (FTIR-ATR) spectroscopy as analytical tools for investigating the drug content in semisolid formulations. Regarding the analytical parameters, this study demonstrates the photothermal beam deflection to be definitely comparable to well established spectroscopic methods for this purpose. The correlation coefficients range from 0.990 to 0.999. Likewise, repeatability and limit of detection are comparable.

  4. Development of processes for the production of solar grade silicon from halides and alkali metals

    Science.gov (United States)

    Dickson, C. R.; Gould, R. K.

    1980-01-01

    High temperature reactions of silicon halides with alkali metals for the production of solar grade silicon in volume at low cost were studied. Experiments were performed to evaluate product separation and collection processes, measure heat release parameters for scaling purposes, determine the effects of reactants and/or products on materials of reactor construction, and make preliminary engineering and economic analyses of a scaled-up process.

  5. Dynamical interaction of He atoms with metal surfaces: Charge transfer processes

    International Nuclear Information System (INIS)

    Flores, F.; Garcia Vidal, F.J.; Monreal, R.

    1993-01-01

    A self-consistent Kohn-Sham LCAO method is presented to calculate the charge transfer processes between a He * -atom and metal surfaces. Intra-atomic correlation effects are taken into account by considering independently each single He-orbital and by combining the different charge transfer processes into a set of dynamical rate equations for the different ion charge fractions. Our discussion reproduces qualitatively the experimental evidence and gives strong support to the method presented here. (author). 24 refs, 4 figs

  6. Metal Removal Process Optimisation using Taguchi Method - Simplex Algorithm (TM-SA) with Case Study Applications

    OpenAIRE

    Ajibade, Oluwaseyi A.; Agunsoye, Johnson O.; Oke, Sunday A.

    2018-01-01

    In the metal removal process industry, the current practice to optimise cutting parameters adoptsa conventional method. It is based on trial and error, in which the machine operator uses experience,coupled with handbook guidelines to determine optimal parametric values of choice. This method is notaccurate, is time-consuming and costly. Therefore, there is a need for a method that is scientific, costeffectiveand precise. Keeping this in mind, a different direction for process optimisation is ...

  7. Semisolid casting with ultrasonically melt-treated billets of Al-7mass%Si alloys

    Directory of Open Access Journals (Sweden)

    Yoshiki Tsunekawa

    2012-02-01

    Full Text Available The demand for high performance cast aluminum alloy components is often disturbed by increasing impurity elements, such as iron accumulated from recycled scraps. It is strongly required that coarse plate-like iron compound of モ-Al5FeSi turns into harmless form without the need for applying refining additives or expensive virgin ingots. The microstructural modification of Al-7mass%Si alloy billets with different iron contents was examined by applying ultrasonic vibration during the solidification. Ultrasonically melt-treated billets were thixocast right after induction heating up to the semisolid temperature of 583 ìC, the microstructure and tensile properties were evaluated in the thixocast components. Globular primary メ-Al is required to fill up a thin cavity in thixocasting, so that the microstructural modification by ultrasonic melt-treatment was firstly confirmed in the billets. With ultrasonic melt-treatment in the temperature range of 630 ìC to 605 ìC, the primary メ-Al transforms itself from dendrite into fine globular in morphology. The coarse plate-like モ-Al5FeSi compound becomes markedly finer compared with those in non-treated billets. Semisolid soaking up to 583 ìC, does not appreciably affect the size of モ-Al5FeSi compounds; however, it affects the solid primary メ-Al morphology to be more globular, which is convenient for thixocasting. After thixocasting with preheated billets, eutectic silicon plates are extremely refined due to the rapid solidification arising from low casting temperature. The tensile strength of thixocast samples with different iron contents does not change much even at 2mass% of iron, when thixocast with ultrasonically melt-treated billets. However, thixocast Al-7mass%Si-2mass%Fe alloy with non-treated billets exhibits an inferior strength of 80 MPa, compared with 180 MPa with ultrasonically melt-treated billets. The elongation is also improved by about a factor of two in thixocastings with

  8. Processing capabilties for the elimination of contaminated metal scrapyards at DOE/ORO-managed sites

    International Nuclear Information System (INIS)

    Mack, J.E.; Williams, L.C.

    1982-01-01

    Capabilities exist for reducing all the contaminated nickel, aluminum, and copper scrap to ingot form by smelting. Processing these metals at existing facilities could be completed in about 5 or 6 years. However, these metals represent only about 20% of the total metal inventories currently on hand at the DOE/ORO-managed sites. No provisions have been made for the ferrous scrap. Most of the ferrous scrap is unclassified and does not require secured storage. Also, the potential resale value of the ferrous scrap at about $100 per ton is very low in comparison. Consequently, this scrap has been allowed to accumulate. With several modifications and equipment additions, the induction melter at PGDP could begin processing ferrous scrap after its commitment to nickel and aluminum. The PGDP smelter is a retrofit installation, and annual throughput capabilities are limited. Processing of the existing ferrous scrap inventories would not be completed until the FY 1995-2000 time frame. An alternative proposal has been the installation of induction melters at the other two enrichment facilities. Conceptual design of a generic metal smelting facility is under way. The design study includes capital and operating costs for scrap preparation through ingot storage at an annual throughput of 10,000 tons per year. Facility design includes an induction melter with the capability of melting both ferrous and nonferrous metals. After three years of operation with scrapyard feed, the smelter would have excess capacity to support on-site decontamination and decomissioning projects or upgrading programs. The metal smelting facility has been proposed for FY 1984 line item funding with start-up operations in FY 1986

  9. Metal flow of a tailor-welded blank in deep drawing process

    Science.gov (United States)

    Yan, Qi; Guo, Ruiquan

    2005-01-01

    Tailor welded blanks were used in the automotive industry to consolidate parts, reduce weight, and increase safety. In recent years, this technology was developing rapidly in China. In Chinese car models, tailor welded blanks had been applied in a lot of automobile parts such as rail, door inner, bumper, floor panel, etc. Concerns on the properties of tailor welded blanks had become more and more important for automobile industry. A lot of research had shown that the strength of the welded seam was higher than that of the base metal, such that the weld failure in the aspect of strength was not a critical issue. However, formability of tailor welded blanks in the stamping process was complex. Among them, the metal flow of tailor welded blanks in the stamping process must be investigated thoroughly in order to reduce the scrap rate during the stamping process in automobile factories. In this paper, the behavior of metal flow for tailor welded blanks made by the laser welding process with two types of different thickness combinations were studied in the deep drawing process. Simulations and experiment verification of the movement of weld line for tailor welded blanks were discussed in detail. Results showed that the control on the movement of welded seam during stamping process by taking some measures in the aspect of blank holder was effective.

  10. On the manufacturing of a gas turbine engine part through metal spinning process

    Science.gov (United States)

    Hassanin, A. El; Astarita, A.; Scherillo, F.; Velotti, C.; Squillace, A.; Liguori, A.

    2018-05-01

    Metal spinning processes represents an interesting alternative to traditional sheet metal forming processes in several industrial contexts, such as automotive and aerospace. In this work, the production of a combustion chamber liner top prototype using AISI 304L stainless steel is proposed, in order to evaluate the process feasibility for the required part geometry. The prototypes production was carried out using a two-stage semiautomatic spinning process. The effects in terms of wall thickness reduction were investigated. Using optical microscopy and Scanning Electron Microscopy (SEM) techniques, the microstructural behavior of the metal subjected to the forming process was investigated, while for an evaluation of the influence on the mechanical properties Vickers micro-indentation tests were performed. The main result of the process, as observed from all the investigation techniques adopted, is the formation of strain induced martensite due to the severe plastic deformation and cold reduction of the material, ranging in this case from 30% to 50%. In some areas of the part section, some rips indicating an excessive tensile stress were also detected.

  11. Uranium Metal to Oxide Conversion by Air Oxidation –Process Development

    Energy Technology Data Exchange (ETDEWEB)

    Duncan, A

    2001-12-31

    Published technical information for the process of metal-to-oxide conversion of uranium components has been reviewed and summarized for the purpose of supporting critical decisions for new processes and facilities for the Y-12 National Security Complex. The science of uranium oxidation under low, intermediate, and high temperature conditions is reviewed. A process and system concept is outlined and process parameters identified for uranium oxide production rates. Recommendations for additional investigations to support a conceptual design of a new facility are outlined.

  12. Monitoring and Control of the Hybrid Laser-Gas Metal-Arc Welding Process

    Energy Technology Data Exchange (ETDEWEB)

    Kunerth, D. C.; McJunkin, T. R.; Nichol, C. I.; Clark, D.; Todorov, E.; Couch, R. D.; Yu, F.

    2013-07-01

    Methods are currently being developed towards a more robust system real time feedback in the high throughput process combining laser welding with gas metal arc welding. A combination of ultrasonic, eddy current, electronic monitoring, and visual techniques are being applied to the welding process. Initial simulation and bench top evaluation of proposed real time techniques on weld samples are presented along with the concepts to apply the techniques concurrently to the weld process. Consideration for the eventual code acceptance of the methods and system are also being researched as a component of this project. The goal is to detect defects or precursors to defects and correct when possible during the weld process.

  13. Simple metal model for predicting uptake and chemical processes in sewage-fed aquaculture ecosystem

    DEFF Research Database (Denmark)

    Azanu, David; Jorgensen, Sven Erik; Darko, Godfred

    2016-01-01

    but not working properly for chromium and mercury. Additional processes, including precipitation of chromium and bio-magnification of methylmercury were introduced to explain concentration of chromium and mercury in fish. Comparison of measured and predicted metal concentration used for validation gave a linear......% was the best, which is also in accordance to the fish growth. The ratio of fish food was also calibrated to be 70% due to a food chain in the water and 30% due to a food chain in the sediment. This gave the lowest uncertainty of the model. The simple metal model was working acceptably well for Pb, Cu and Cd...

  14. Survey the Effect of Pistachio Waste Composting Process with Different Treatments on Concentration of Heavy Metals

    Directory of Open Access Journals (Sweden)

    M Jalili

    2016-09-01

    Full Text Available Abstract Introduction: Composting is one of the pistachio wastes management methods. In the appropriate compost production nutrients and heavy metals are determinant. The aim of this study is survey the effect of pistachio wastes composting process with different treatments on the concentration of heavy metals. Methods: In this study, during the 60-day pistachio wastes composting process with two treatments of dewatered sewage sludge and cow manure, pH, EC, carbon to nitrogen ratio, Heavy metals and nutrients indicators were studied. The results were compared with WHO and Iranian National standard. Drawing the diagrams by Excel software (Version 2007 and Statistical analysis was performed by Spss Software (version 20 at a significance level of 0.005.  Results: During the 60-day composting pH initially had downward trend and then increased. The Cu, Zn, Fe, Mn and C/N ratio had downward trend and the EC, Na, K had increasing trend. Eventually, Iron, zinc, copper and manganese were less than the standard, Sodium was in Standard range and potassium was more than specified standards in the produced compost from pistachios waste with both treatments.  Conclusion: The results showed that the concentration of heavy metals and nutrients in the produced compost with both treatments were in the acceptable range. Eventually quality of produced compost with cow manure treatment due to better decomposition and greater stability was better than processed compost with dewatered sewage sludge treatment.

  15. Solidification of metal chloride waste from pyrochemical process via dechlorination-chlorination reaction system

    Energy Technology Data Exchange (ETDEWEB)

    Park, H.S.; Cho, I.H.; Lee, K.R.; Choi, J.H.; Eun, H.C.; Kim, I.T.; Park, G.I. [Korea Atomic Energy Research Inst., Deajeon (Korea, Republic of)

    2014-07-01

    The metal chloride wastes generated from the pyro-chemical process to recover uranium and TRUs has been considered as a problematic waste due to the high volatility and low compatibility with conventional silicate glass. Our research group has suggested the dechlorination approach for the solidification of this kind of waste by using a synthetic composite, SAP (SiO{sub 2}-Al{sub 2}O{sub 3}-P{sub 2}O{sub 5}). During the dechlorination, metal elements are chemically interacted with the inorganic composite, SAP, while chlorine is vaporized as gaseous chlorine. Metal elements in the salt were immobilized into phosphate and silicate glass which are uniformly distributed in tens of nm scale. During the dechlorination, gaseous chlorine is captured by Li{sub 2}O-Li{sub 2}O{sub 2} composite that can be converted into metal chloride (LiCl). About 98wt% of oxide composite was converted into LiCl that can be used as an electrolyte in the electrochemical process. The method suggested in this study can provide a chance to minimize the waste volume for the final disposal of salt wastes from a pyro-chemical process. (author)

  16. Initial Evaluation of Processing Methods for an Epsilon Metal Waste Form

    International Nuclear Information System (INIS)

    Crum, Jarrod V.; Strachan, Denis M.; Zumhoff, Mac R.

    2012-01-01

    During irradiation of nuclear fuel in a reactor, the five metals, Mo, Pd, Rh, Ru, and Tc, migrate to the fuel grain boundaries and form small metal particles of an alloy known as epsilon metal ((var e psilon)-metal). When the fuel is dissolved in a reprocessing plant, these metal particles remain behind with a residue - the undissolved solids (UDS). Some of these same metals that comprise this alloy that have not formed the alloy are dissolved into the aqueous stream. These metals limit the waste loading for a borosilicate glass that is being developed for the reprocessing wastes. Epsilon metal is being developed as a waste form for the noble metals from a number of waste streams in the aqueous reprocessing of used nuclear fuel (UNF) - (1) the (var e psilon)-metal from the UDS, (2) soluble Tc (ion-exchanged), and (3) soluble noble metals (TRUEX raffinate). Separate immobilization of these metals has benefits other than allowing an increase in the glass waste loading. These materials are quite resistant to dissolution (corrosion) as evidenced by the fact that they survive the chemically aggressive conditions in the fuel dissolver. Remnants of (var e psilon)-metal particles have survived in the geologically natural reactors found in Gabon, Africa, indicating that they have sufficient durability to survive for ∼ 2.5 billion years in a reducing geologic environment. Additionally, the (var e psilon)-metal can be made without additives and incorporate sufficient foreign material (oxides) that are also present in the UDS. Although (var e psilon)-metal is found in fuel and Gabon as small particles (∼10 (micro)m in diameter) and has survived intact, an ideal waste form is one in which the surface area is minimized. Therefore, the main effort in developing (var e psilon)-metal as a waste form is to develop a process to consolidate the particles into a monolith. Individually, these metals have high melting points (2617 C for Mo to 1552 C for Pd) and the alloy is expected

  17. Radiation-induced processes in the metallic powders after electron and gamma-radiation

    International Nuclear Information System (INIS)

    Zajkin, Yu.A.; Aliev, B.A.

    2001-01-01

    In the work the quantitative assessments for conditions both healing and growth of micropores in metal volume and surface layers have been made. Taking into account of these rules is important at a choice of radiation processing conditions for fine-disperse powders characterizing with increased porosity. Numerical evaluation shows, that under irradiation of a metals by electrons with energy 2 MeV and electron current density about 1 μA/cm 2 within 300-400 K temperature range the optimal doses for the micropores healing make up a several Mrad. Further increase of dose could lead to formation of pores in the crystal volume. Principal conclusions about radiation porosity development character of metallic particles surface layers one can make from analysis of the point defects distribution near surface and computing of radiation-induced diffusion coefficients

  18. Simultaneous heavy metals removal and municipal sewage sludge dewaterability improvement in bioleaching processes by various inoculums.

    Science.gov (United States)

    Shi, Chaohong; Zhu, Nengwu; Shang, Ru; Kang, Naixin; Wu, Pingxiao

    2015-11-01

    The heavy metals content and dewaterability of municipal sewage sludge (MSS) are important parameters affecting its subsequent disposal and land application. Six kinds of inoculums were prepared to examine the characteristics of heavy metals removal and MSS dewaterability improvement in bioleaching processes. The results showed that Cu, Zn and Cd bioleaching efficiencies (12 days) were 81-91, 87-93 and 81-89%, respectively, which were significantly higher than those of Fe-S control (P bioleaching boosted by the prepared inoculums could also significantly enhance MSS dewaterability (P bioleaching for heavy metals removal and dewaterability improvement. It also suggested that the synergy of sulfur/ferrous-oxidizing bacteria (SFOB) enriched from AMD and the cooperation of exogenous and indigenous SFOB significantly promoted bioleaching efficiencies.

  19. Thin layer activation : on-line monitoring of metal loss in process plant

    International Nuclear Information System (INIS)

    Boulton, L.H.; Wallace, G.

    1993-01-01

    Corrosion, erosion and wear of metals is a common cause of failure in some process plant and equipment. Monitoring of these destructive effects has been done for many years to help plant engineers minimise the damage, in order to avoid unexpected failures and unscheduled shutdowns. Traditional methods of monitoring, such as standard NDT techniques, inform the engineer of what has happened, providing data such as culmulative loss of wall thickness. The modern approach to monitoring however, is to employ a technique which gives both current loss rates as well as integrated losses. Thin Layer Activation (TLA) provides on-line monitoring of corrosion, erosion and wear of metals, to a high degree of accuracy. It also gives cumulative information which can be backed up with weight-loss results if required. Thus current rather than historical loss rates are measured before any significant loss of metal has occurred. (author). 14 refs., 2 figs

  20. Deposition of metallic nanoparticles on carbon nanotubes via a fast evaporation process

    International Nuclear Information System (INIS)

    Ren Guoqiang; Xing Yangchuan

    2006-01-01

    A new technique was developed for the deposition of colloidal metal nanoparticles on carbon nanotubes. It involves fast evaporation of a suspension containing sonochemically functionalized carbon nanotubes and colloidal nanoparticles. It was demonstrated that metallic nanoparticles with different sizes and concentrations can be deposited on the carbon nanotubes with only a few agglomerates. The technique does not seem to be limited by what the nanoparticles are, and therefore would be applicable to the deposition of other nanoparticles on carbon nanotubes. PtPd and CoPt 3 alloy nanoparticles were used to demonstrate the deposition process. It was found that the surfactants used to disperse the nanoparticles can hinder the nanoparticle deposition. When the nanoparticles were washed with ethanol, they could be well deposited on the carbon nanotubes. The obtained carbon nanotube supported metal nanoparticles were characterized by transmission electron microscopy, energy dispersive x-ray spectroscopy, x-ray photoelectron spectroscopy, and cyclic voltammetry

  1. On the self-diffusion process in liquid metals and alloys by the radioactive tracer method

    International Nuclear Information System (INIS)

    Ganovici, L.

    1978-01-01

    A theoretical and experimental study of self-diffusion process in liquid metals and alloys is presented. There are only a few pure metals for which diffusion coefficients in a liquid state are known. The thesis aims at increasing the number of liquid metals for which diffusion coefficients are available, by determining these values for liquids: Cd, Tl, Sb and Te. The self-diffusion coefficients of Te in some tellurium based liquid alloys such as Tl 2 Te, PbTe and Bi 90 Te 10 were also determined. Self-diffusion coefficients have been measured using two radioactive tracer methods: a) the capillary-reservoir method; b) the semi-infinite capillary method. The self-diffusion coefficients were derived from the measured radioactive concentration profile, using the solutions of Fick's second law for appropriate initial and limit conditions. The temperature dependence study of self-diffusion coefficients in liquids Cd, Tl, Sb and Te, was used to check some theoretical models on the diffusion mechanism in metallic melts. The experimental diffusion data interpreted in terms of the Arrhenius type temperature dependence, was used to propose two simple empiric relations for determining self diffusion coefficients of group I liquid metals and for liquid semi-metals. It was established a marked decrease of self-diffusion coefficients of liquid Te close to the solidification temperature. The diffusivity of Te in liquid Tl 2 Te points to an important decrease close to the solidification temperature. A simplified model was proposed for the diffusion structural unit in this alloy and the hard sphere model for liquid metals was checked by comparing the theoretical and experimental self-diffusion coefficients. (author)

  2. Process for the production of metal nitride sintered bodies and resultant silicon nitride and aluminum nitride sintered bodies

    Science.gov (United States)

    Yajima, S.; Omori, M.; Hayashi, J.; Kayano, H.; Hamano, M.

    1983-01-01

    A process for the manufacture of metal nitride sintered bodies, in particular, a process in which a mixture of metal nitrite powders is shaped and heated together with a binding agent is described. Of the metal nitrides Si3N4 and AIN were used especially frequently because of their excellent properties at high temperatures. The goal is to produce a process for metal nitride sintered bodies with high strength, high corrosion resistance, thermal shock resistance, thermal shock resistance, and avoidance of previously known faults.

  3. Failure Analysis of a Sheet Metal Blanking Process Based on Damage Coupling Model

    Science.gov (United States)

    Wen, Y.; Chen, Z. H.; Zang, Y.

    2013-11-01

    In this paper, a blanking process of sheet metal is studied by the methods of numerical simulation and experimental observation. The effects of varying technological parameters related to the quality of products are investigated. An elastoplastic constitutive equation accounting for isotropic ductile damage is implemented into the finite element code ABAQUS with a user-defined material subroutine UMAT. The simulations of the damage evolution and ductile fracture in a sheet metal blanking process have been carried out by the FEM. In order to guarantee computation accuracy and avoid numerical divergence during large plastic deformation, a specified remeshing technique is successively applied when severe element distortion occurs. In the simulation, the evolutions of damage at different stage of the blanking process have been evaluated and the distributions of damage obtained from simulation are in proper agreement with the experimental results.

  4. Time resolved Thomson scattering diagnostic of pulsed gas metal arc welding (GMAW) process

    International Nuclear Information System (INIS)

    Kühn-Kauffeldt, M; Schein, J; Marquès, J L

    2014-01-01

    In this work a Thomson scattering diagnostic technique was applied to obtain time resolved electron temperature and density values during a gas metal arc welding (GMAW) process. The investigated GMAW process was run with aluminum wire (AlMg 4,5 Mn) with 1.2 mm diameter as a wire electrode, argon as a shielding gas and peak currents in the range of 400 A. Time resolved measurements could be achieved by triggering the laser pulse at shifted time positions with respect to the current pulse driving the process. Time evaluation of resulting electron temperatures and densities is used to investigate the state of the plasma in different phases of the current pulse and to determine the influence of the metal vapor and droplets on the plasma properties

  5. Microstructure characteristics of nickel reinforced metal matrix composites (Ni/AC8A) by low-pressure metal infiltration process

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hyun Jun; Rong, Hua Wei; Jun, Ji Ang; Park, Sung Ho; Huh, Sun Chul; Park, Won Jo [Gyeongsang National University, Jinju (Korea, Republic of)

    2009-07-01

    MMCs(Metal Matrix Composites) can obtain mechanical characteristics of application purposes that a single material is difficult to obtain. Al alloy composite material that nickel is added by reinforcement is used for piston of diesel engine, because high temperature properties, strength, corrosion resistant are improved excellently than existent Al alloy. And, in case of processing, interface between Ni and Al improves wear resistant by intermetallic compound of high hardness. Also, in the world, industrial circles are proceeding research to apply excellent composite material. Existent process methods of MMC using preform were manufactured by high-pressure. But, it cause deformation of preform or fault of completed MMC. Using low-pressure as infiltration pressure can prevent this problem, and there is an advantage that is able to reduce the cost of production by small scale of production equipment. Accordingly, process methods of MMC have to consider low-pressure infiltration for the strength of preform, and nowadays, there are many studies about reducing infiltration pressure. In this study produced Al composite material that Ni is added by reinforcement by low-pressure infiltration, and observed microstructure of completed MMCs.

  6. Improving Passivation Process of Si Nanocrystals Embedded in SiO2 Using Metal Ion Implantation

    Directory of Open Access Journals (Sweden)

    Jhovani Bornacelli

    2013-01-01

    Full Text Available We studied the photoluminescence (PL of Si nanocrystals (Si-NCs embedded in SiO2 obtained by ion implantation at MeV energy. The Si-NCs are formed at high depth (1-2 μm inside the SiO2 achieving a robust and better protected system. After metal ion implantation (Ag or Au, and a subsequent thermal annealing at 600°C under hydrogen-containing atmosphere, the PL signal exhibits a noticeable increase. The ion metal implantation was done at energies such that its distribution inside the silica does not overlap with the previously implanted Si ion . Under proper annealing Ag or Au nanoparticles (NPs could be nucleated, and the PL signal from Si-NCs could increase due to plasmonic interactions. However, the ion-metal-implantation-induced damage can enhance the amount of hydrogen, or nitrogen, that diffuses into the SiO2 matrix. As a result, the surface defects on Si-NCs can be better passivated, and consequently, the PL of the system is intensified. We have selected different atmospheres (air, H2/N2 and Ar to study the relevance of these annealing gases on the final PL from Si-NCs after metal ion implantation. Studies of PL and time-resolved PL indicate that passivation process of surface defects on Si-NCs is more effective when it is assisted by ion metal implantation.

  7. Application of Characterization, Modeling, and Analytics Towards Understanding Process Structure Linkages in Metallic 3D Printing (Postprint)

    Science.gov (United States)

    2017-08-01

    METALLIC 3D PRINTING (POSTPRINT) M.A. Groeber, E. Schwalbach, S. Donegan, K. Chaput, T. Butler, and J. Miller AFRL/RX 27 JULY...MODELING, AND ANALYTICS TOWARDS UNDERSTANDING PROCESS- STRUCTURE LINKAGES IN METALLIC 3D PRINTING (POSTPRINT) 5a. CONTRACT NUMBER IN-HOUSE 5b...characterization, modelling, and analytics towards understanding process-structure linkages in metallic 3D printing M A Groeber, E Schwalbach, S Donegan, K

  8. Exploring imperfect squeezing flow measurements in a Teflon geometry for semisolid foods.

    Science.gov (United States)

    Terpstra, M E J; Janssen, A M; Linden, E van der

    2007-11-01

    The method of imperfect lubricated squeezing flow in a Teflontrade mark geometry has been explored for the characterization of elongational behavior of custard and mayonnaise. Two Newtonian products, one of low (0.07 Pas) and one of high (18 Pas) shear viscosity, were used as references. Measurements of custards and mayonnaises did not behave according to either the theory of lubricated or nonlubricated squeezing flow, as there were effects of the initial sample height and compression speed. Also, calculated values for the flow index were not as we had expected. The same was true for the Newtonian samples. An important factor explaining the effect of compression speed was the presence of a certain amount of friction, rendering both lubricated theory and nonlubricated theory nonapplicable. Correcting for (pseudo-) thixotropic behavior of custard and mayonnaise appears to be an effective way of obtaining realistic values for the flow index. The presence of buoyancy also affected the results, especially in the case of low viscous products and the effect of initial sample height. Other factors that played a role in the results were yield stress for custard and mayonnaise and instrumental artifacts associated with the imperfect setup of the measurement, especially for the highly viscous products. Quantitatively correcting the results for all of these factors is not possible at this point. Although the imperfect squeezing flow technique in a Teflon geometry is a very practical way to measure semisolids such as custard and mayonnaise under (partly) elongational deformation, the results should be regarded as more qualitative than quantitative.

  9. Low Temperature Synthesis of Metal Oxides by a Supercritical Seed Enhanced Crystallization (SSEC) Process

    DEFF Research Database (Denmark)

    Jensen, Henrik; Brummerstedt Iversen, Steen; Joensen, Karsten Dan

    2006-01-01

    A novel method for producing crystalline nanosized metal oxides by a Supercritical Seed Enhanced Crystallization (SSEC) Process has been developed. The process is a modified sol-gel process taking place at temperatures as low as 95 ºC with supercritical CO2 as solvent and polypropylene as seeding...... material. The nanocrystalline product is obtained without having to resort to costly post-reaction processing and the product is obtained directly after the SSEC process. TiO2 powders produced by the SSEC process were shown to have a crystallinity of 60 % and a crystal size of 7.3 ± 2.6 nm....... The crystallinity can be controlled by changing the heating rate of the initial formation of the nanoparticles and the morphology can be altered by changing the process time....

  10. Effect of process parameters on hardness, temperature profile and solidification of different layers processed by direct metal laser sintering (DMLS)

    International Nuclear Information System (INIS)

    Ahmed, Sazzad Hossain; Mian, Ahsan; Srinivasan, Raghavan

    2016-01-01

    In DMLS process objects are fabricated layer by layer from powdered material by melting induced by a controlled laser beam. Metallic powder melts and solidifies to form a single layer. Solidification map during layer formation is an important route to characterize micro-structure and grain morphology of sintered layer. Generally, solidification leads to columnar, equiaxed or mixture of these two types grain morphology depending on solidification rate and thermal gradient. Eutectic or dendritic structure can be formed in fully equiaxed zone. This dendritic growth has a large effect on material properties. Smaller dendrites generally increase ductility of the layer. Thus, materials can be designed by creating desired grain morphology in certain regions using DMLS process. To accomplish this, hardness, temperature distribution, thermal gradient and solidification cooling rate in processed layers will be studied under change of process variables by using finite element analysis, with specific application to Ti-6Al-4V.

  11. Effect of process parameters on hardness, temperature profile and solidification of different layers processed by direct metal laser sintering (DMLS)

    Science.gov (United States)

    Ahmed, Sazzad Hossain; Mian, Ahsan; Srinivasan, Raghavan

    2016-07-01

    In DMLS process objects are fabricated layer by layer from powdered material by melting induced by a controlled laser beam. Metallic powder melts and solidifies to form a single layer. Solidification map during layer formation is an important route to characterize micro-structure and grain morphology of sintered layer. Generally, solidification leads to columnar, equiaxed or mixture of these two types grain morphology depending on solidification rate and thermal gradient. Eutectic or dendritic structure can be formed in fully equiaxed zone. This dendritic growth has a large effect on material properties. Smaller dendrites generally increase ductility of the layer. Thus, materials can be designed by creating desired grain morphology in certain regions using DMLS process. To accomplish this, hardness, temperature distribution, thermal gradient and solidification cooling rate in processed layers will be studied under change of process variables by using finite element analysis, with specific application to Ti-6Al-4V.

  12. Effect of process parameters on hardness, temperature profile and solidification of different layers processed by direct metal laser sintering (DMLS)

    Energy Technology Data Exchange (ETDEWEB)

    Ahmed, Sazzad Hossain; Mian, Ahsan, E-mail: ahsan.mian@wright.edu; Srinivasan, Raghavan [Department of Mechanical and Materials Engineering, Wright State University, Dayton, Ohio 45435 (United States)

    2016-07-12

    In DMLS process objects are fabricated layer by layer from powdered material by melting induced by a controlled laser beam. Metallic powder melts and solidifies to form a single layer. Solidification map during layer formation is an important route to characterize micro-structure and grain morphology of sintered layer. Generally, solidification leads to columnar, equiaxed or mixture of these two types grain morphology depending on solidification rate and thermal gradient. Eutectic or dendritic structure can be formed in fully equiaxed zone. This dendritic growth has a large effect on material properties. Smaller dendrites generally increase ductility of the layer. Thus, materials can be designed by creating desired grain morphology in certain regions using DMLS process. To accomplish this, hardness, temperature distribution, thermal gradient and solidification cooling rate in processed layers will be studied under change of process variables by using finite element analysis, with specific application to Ti-6Al-4V.

  13. Production of metal fullerene surface layer from various media in the process of steel carbonization

    Directory of Open Access Journals (Sweden)

    KUZEEV Iskander Rustemovich

    2018-04-01

    Full Text Available Studies devoted to production of metal fullerene layer in steels when introducing carbon from organic and inorganic media were performed. Barium carbonate was used as an inorganic medium and petroleum pitch was used as an organic medium. In order to generate the required amount of fullerenes in the process of steel samples carbonization, optimal temperature mode was found. The higher temperature, absorption and cohesive effects become less important and polymeric carbon structures destruction processes become more important. On the bottom the temperature is limited by petroleum pitch softening temperature and its transition to low-viscous state in order to enhance molecular mobility and improve the possibility of their diffusion to metal surface. Identification of fullerenes in the surface modified layer was carried out following the methods of IR-Fourier spectrometry and high-performance liquid chromatography. It was found out that nanocarbon structures, formed during carbonization in barium carbonate and petroleum pitch mediums, possess different morphology. In the process of metal carbonization from carbonates medium, the main role in fullerenes synthesis is belonged to catalytic effect of surface with generation of endohedral derivatives in the surface layer; but in the process of carbonization from pitch medium fullerenes are formed during crystallization of the latter and crystallization centers are of fullerene type. Based on theoretical data and dataof spectral and chromatographic analysis, optimal conditions of metal fullerene layer formation in barium carbonate and petroleum pitch mediums were determined. Low cohesion of layer, modified in barium carbonate medium, with metal basis was discovered. That was caused by limited carbon diffusion in the volume of α-Fe. According to the detected mechanism of fullerenes formation on steel surface in gaseous medium, fullerenes are formed on catalytic centers – ferrum atoms, forming thin metal

  14. Process defects and in situ monitoring methods in metal powder bed fusion: a review

    Science.gov (United States)

    Grasso, Marco; Colosimo, Bianca Maria

    2017-04-01

    Despite continuous technological enhancements of metal Additive Manufacturing (AM) systems, the lack of process repeatability and stability still represents a barrier for the industrial breakthrough. The most relevant metal AM applications currently involve industrial sectors (e.g. aerospace and bio-medical) where defects avoidance is fundamental. Because of this, there is the need to develop novel in situ monitoring tools able to keep under control the stability of the process on a layer-by-layer basis, and to detect the onset of defects as soon as possible. On the one hand, AM systems must be equipped with in situ sensing devices able to measure relevant quantities during the process, a.k.a. process signatures. On the other hand, in-process data analytics and statistical monitoring techniques are required to detect and localize the defects in an automated way. This paper reviews the literature and the commercial tools for in situ monitoring of powder bed fusion (PBF) processes. It explores the different categories of defects and their main causes, the most relevant process signatures and the in situ sensing approaches proposed so far. Particular attention is devoted to the development of automated defect detection rules and the study of process control strategies, which represent two critical fields for the development of future smart PBF systems.

  15. Process defects and in situ monitoring methods in metal powder bed fusion: a review

    International Nuclear Information System (INIS)

    Grasso, Marco; Colosimo, Bianca Maria

    2017-01-01

    Despite continuous technological enhancements of metal Additive Manufacturing (AM) systems, the lack of process repeatability and stability still represents a barrier for the industrial breakthrough. The most relevant metal AM applications currently involve industrial sectors (e.g. aerospace and bio-medical) where defects avoidance is fundamental. Because of this, there is the need to develop novel in situ monitoring tools able to keep under control the stability of the process on a layer-by-layer basis, and to detect the onset of defects as soon as possible. On the one hand, AM systems must be equipped with in situ sensing devices able to measure relevant quantities during the process, a.k.a. process signatures. On the other hand, in-process data analytics and statistical monitoring techniques are required to detect and localize the defects in an automated way. This paper reviews the literature and the commercial tools for in situ monitoring of powder bed fusion (PBF) processes. It explores the different categories of defects and their main causes, the most relevant process signatures and the in situ sensing approaches proposed so far. Particular attention is devoted to the development of automated defect detection rules and the study of process control strategies, which represent two critical fields for the development of future smart PBF systems. (paper)

  16. Mass production of multi-wall carbon nanotubes by metal dusting process with high yield

    Energy Technology Data Exchange (ETDEWEB)

    Ghorbani, H. [School of Metallurgy and Materials Engineering, Iran University of Science and Technology, Narmak, Tehran (Iran, Islamic Republic of); Rashidi, A.M., E-mail: Rashidiam@ripi.ir [Nanotechnology Research Center, Research Institute of Petroleum Industry (RIPI), West Blvd. Azadi Sport Complex, P.O. Box 14665-1998, Tehran (Iran, Islamic Republic of); Rastegari, S.; Mirdamadi, S. [School of Metallurgy and Materials Engineering, Iran University of Science and Technology, Narmak, Tehran (Iran, Islamic Republic of); Alaei, M. [Nanotechnology Research Center, Research Institute of Petroleum Industry (RIPI), West Blvd. Azadi Sport Complex, P.O. Box 14665-1998, Tehran (Iran, Islamic Republic of)

    2011-05-15

    Research highlights: {yields} Synthesis of carbon nanotubes over Fe-Ni nanoparticles supported alloy 304L. {yields} Production of carbon nanotubes with high yield (700-1000%) and low cost catalyst. {yields} Optimum growth condition is CO/H{sub 2} = 1/1, 100 cm{sup 3}/min, at 620 {sup o}C under long term repetitive thermal cycling. {yields} Possibility of the mass production by metal dusting process with low cost. -- Abstract: Carbon nanotube materials were synthesized over Fe-Ni nanoparticles generated during disintegration of the surface of alloy 304L under metal dusting environment. The metal dusting condition was simulated and optimized through exposing stainless steel samples during long term repetitive thermal cycling in CO/H{sub 2} = 1/1, total gas flow rate 100 cm{sup 3}/min, at 620 {sup o}C for 300 h. After reaction, surface morphology of the samples and also carbonaceous deposition which had grown on sample surfaces were examined by stereoscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Results revealed that multi-wall carbon nanotubes could be formed over nanocatalyst generated on the alloy surface by exploiting metal dusting process. By optimization of reaction parameters the yields of carbon nanotube materials obtained were 700-1000%. Also it has been shown herein that the amount of carbon nanotube materials remarkably increases when the reaction time is extended up to 300 h, indicating a possibility of the mass production by this easy method.

  17. Mass production of multi-wall carbon nanotubes by metal dusting process with high yield

    International Nuclear Information System (INIS)

    Ghorbani, H.; Rashidi, A.M.; Rastegari, S.; Mirdamadi, S.; Alaei, M.

    2011-01-01

    Research highlights: → Synthesis of carbon nanotubes over Fe-Ni nanoparticles supported alloy 304L. → Production of carbon nanotubes with high yield (700-1000%) and low cost catalyst. → Optimum growth condition is CO/H 2 = 1/1, 100 cm 3 /min, at 620 o C under long term repetitive thermal cycling. → Possibility of the mass production by metal dusting process with low cost. -- Abstract: Carbon nanotube materials were synthesized over Fe-Ni nanoparticles generated during disintegration of the surface of alloy 304L under metal dusting environment. The metal dusting condition was simulated and optimized through exposing stainless steel samples during long term repetitive thermal cycling in CO/H 2 = 1/1, total gas flow rate 100 cm 3 /min, at 620 o C for 300 h. After reaction, surface morphology of the samples and also carbonaceous deposition which had grown on sample surfaces were examined by stereoscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Results revealed that multi-wall carbon nanotubes could be formed over nanocatalyst generated on the alloy surface by exploiting metal dusting process. By optimization of reaction parameters the yields of carbon nanotube materials obtained were 700-1000%. Also it has been shown herein that the amount of carbon nanotube materials remarkably increases when the reaction time is extended up to 300 h, indicating a possibility of the mass production by this easy method.

  18. Application of Electrochemical Process in Removal of Heavy Metals from Landfill Leachate

    Directory of Open Access Journals (Sweden)

    Mostafaii Gh.1 PhD,

    2016-08-01

    Full Text Available Aims Municipal landfill leachate contains high concentrations of heavy metals, organics, ammonia. The efficeincy of electrochemically removal of heavy metals from landfill leachate was studied. Materials & Methods The leachate was obtained from Kahrizak landfill in south of Tehran. The experiments were carried out by batch process. The 2liter batch reactor was made of glass. There were eight anodes and cathodes electrodes. The electrodes were placed vertically parallel to each other and they were connected to a digital DC power supply. The pH and conductivity were adjusted to a desirable value using NaOH or H2SO4, and NaCl. All the runs were performed at constant temperature of 25°C. In each run, 1.5liter of the leachate was placed into the electrolytic cell. Samples were extracted every 10min and then filtered through a mixed cellulose acetate membrane (0.42μm. The amount of Lead, Zinc and Nickel removal was measured at pH=7 and in current density of 0.5, 0.75, and 1A. Findings When current density and time reaction increased, removal efficiency of heavy metals such as Lead, Zinc and Nickel increased. At initial pH=7, density 1A and reaction time= 60min, Lead, Nickel and Zinc were removed up to 86, 93 and 95%, respectively. Conclusion Electrochemical process can be proposed as a suitable technique to remove heavy metal from landfill leachate.

  19. Influence of voltage input to heavy metal removal from electroplating wastewater using electrocoagulation process

    Science.gov (United States)

    Wulan, D. R.; Cahyaningsih, S.; Djaenudin

    2017-03-01

    In medium capacity, electroplating industry usually treats wastewater until 5 m3 per day. Heavy metal content becomes concern that should be reduced. Previous studies performed electrocoagulation method on laboratory scale, either batch or continuous. This study was aimed to compare the influence of voltage input variation into heavy metal removal in electroplating wastewater treatment using electrocoagulation process on laboratory-scale in order to determine the optimum condition for scaling up the reactor into pilot-scale. The laboratory study was performed in 1.5 L glass reactor in batch system using wastewater from electroplating industry, the voltage input varied at 20, 30 and 40 volt. The electrode consisted of aluminium 32 cm2 as sacrifice anode and copper 32 cm2 as cathode. During 120 min electrocoagulation process, the pH value was measured using pH meter, whereas the heavy metal of chromium, copper, iron, and zinc concentration were analysed using Atomic Absorption Spectrophotometer (AAS). Result showed that removal of heavy metals from wastewater increased due to the increasing of voltage input. Different initial concentration of heavy metals on wastewater, resulted the different detention time. At pilot-scale reactor with 30 V voltage input, chromium, iron, and zinc reached removal efficiency until 89-98%, when copper reached 79% efficiency. At 40V, removal efficiencies increased on same detention time, i.e. chromium, iron, and zinc reached 89-99%, whereas copper reached 85%. These removal efficiencies have complied the government standard except for copper that had higher initial concentration in wastewater. Kinetic rate also calculated in this study as the basic factor for scaling up the process.

  20. Optimal fabrication processes for unidirectional metal-matrix composites: A computational simulation

    Science.gov (United States)

    Saravanos, D. A.; Murthy, P. L. N.; Morel, M.

    1990-01-01

    A method is proposed for optimizing the fabrication process of unidirectional metal matrix composites. The temperature and pressure histories are optimized such that the residual microstresses of the composite at the end of the fabrication process are minimized and the material integrity throughout the process is ensured. The response of the composite during the fabrication is simulated based on a nonlinear micromechanics theory. The optimal fabrication problem is formulated and solved with non-linear programming. Application cases regarding the optimization of the fabrication cool-down phases of unidirectional ultra-high modulus graphite/copper and silicon carbide/titanium composites are presented.

  1. Optimal fabrication processes for unidirectional metal-matrix composites - A computational simulation

    Science.gov (United States)

    Saravanos, D. A.; Murthy, P. L. N.; Morel, M.

    1990-01-01

    A method is proposed for optimizing the fabrication process of unidirectional metal matrix composites. The temperature and pressure histories are optimized such that the residual microstresses of the composite at the end of the fabrication process are minimized and the material integrity throughout the process is ensured. The response of the composite during the fabrication is simulated based on a nonlinear micromechanics theory. The optimal fabrication problem is formulated and solved with nonlinear programming. Application cases regarding the optimization of the fabrication cool-down phases of unidirectional ultra-high modulus graphite/copper and silicon carbide/titanium composites are presented.

  2. Metallization and photolithographic processes and procedures for MC2730 RTG thermopile intraconnections

    International Nuclear Information System (INIS)

    Komarek, E.E.; Wright, R.E.; Knauss, G.L.

    1974-03-01

    Processes and procedures were developed for applying the thin film tungsten electrical intraconnections to the MC2730 RTG ''one-dimensional'' thermopile. After polishing, the surface to be metallized was cleaned with a detergent/organic solvent procedure and then etched with hydrofluoric acid to minimize the oxide. Tungsten contacts were sputtered onto the thermopile and the individual contacts photolithographically defined using a negative acting photoresist in conjunction with a potassium ferricyanide etchant. The processes were used to process 89 thermopiles with an 80 percent effective yield

  3. Impact of process temperature on GaSb metal-oxide-semiconductor interface properties fabricated by ex-situ process

    Energy Technology Data Exchange (ETDEWEB)

    Yokoyama, Masafumi, E-mail: yokoyama@mosfet.t.u-tokyo.ac.jp; Takenaka, Mitsuru; Takagi, Shinichi [Department of Electrical Engineering and Information Systems, The University of Tokyo, Yayoi 2-11-16, Bunkyo, Tokyo 113-0032 (Japan); JST-CREST, Yayoi 2-11-16, Bunkyo, Tokyo 113-0032 (Japan); Asakura, Yuji [Department of Electrical Engineering and Information Systems, The University of Tokyo, Yayoi 2-11-16, Bunkyo, Tokyo 113-0032 (Japan); Yokoyama, Haruki [NTT Photonics Laboratories, NTT Corporation, Atsugi 243-0198 (Japan)

    2014-06-30

    We have studied the impact of process temperature on interface properties of GaSb metal-oxide-semiconductor (MOS) structures fabricated by an ex-situ atomic-layer-deposition (ALD) process. We have found that the ALD temperature strongly affects the Al{sub 2}O{sub 3}/GaSb MOS interface properties. The Al{sub 2}O{sub 3}/GaSb MOS interfaces fabricated at the low ALD temperature of 150 °C have the minimum interface-trap density (D{sub it}) of ∼4.5 × 10{sup 13 }cm{sup −2} eV{sup −1}. We have also found that the post-metalization annealing at temperature higher than 200 °C degrades the Al{sub 2}O{sub 3}/GaSb MOS interface properties. The low-temperature process is preferable in fabricating GaSb MOS interfaces in the ex-situ ALD process to avoid the high-temperature-induced degradations.

  4. Molten salt extraction process for the recovery of valued transition metals from land-based and deep-sea minerals

    Science.gov (United States)

    Maroni, V.A.; von Winbush, S.

    1987-05-01

    A process for extracting transition metals and particularly cobalt and manganese together with iron, copper and nickel from low grade ores (including ocean-floor nodules) by converting the metal oxides or other compositions to chlorides in a molten salt, and subsequently using a combination of selective distillation at temperatures below about 500/degree/C, electrolysis at a voltage not more negative that about /minus/1.5 volt versus Ag/AgCl, and precipitation to separate the desired manganese and cobalt salts from other metals and provide cobalt and manganese in metallic forms or compositions from which these metals may be more easily recovered.

  5. Selective removal/recovery of RCRA metals from waste and process solutions using polymer filtration{trademark} technology

    Energy Technology Data Exchange (ETDEWEB)

    Smith, B.F. [Los Alamos National Lab., NM (United States)

    1997-10-01

    Resource Conservation and Recovery Act (RCRA) metals are found in a number of process and waste streams at many DOE, U.S. Department of Defense, and industrial facilities. RCRA metals consist principally of chromium, mercury, cadmium, lead, and silver. Arsenic and selenium, which form oxyanions, are also considered RCRA elements. Discharge limits for each of these metals are based on toxicity and dictated by state and federal regulations (e.g., drinking water, RCRA, etc.). RCRA metals are used in many current operations, are generated in decontamination and decommissioning (D&D) operations, and are also present in old process wastes that require treatment and stabilization. These metals can exist in solutions, as part of sludges, or as contaminants on soils or solid surfaces, as individual metals or as mixtures with other metals, mixtures with radioactive metals such as actinides (defined as mixed waste), or as mixtures with a variety of inert metals such as calcium and sodium. The authors have successfully completed a preliminary proof-of-principle evaluation of Polymer Filtration{trademark} (PF) technology for the dissolution of metallic mercury and have also shown that they can remove and concentrate RCRA metals from dilute solutions for a variety of aqueous solution types using PF technology. Another application successfully demonstrated is the dilute metal removal of americium and plutonium from process streams. This application was used to remove the total alpha contamination to below 30 pCi/L for the wastewater treatment plant at TA-50 at Los Alamos National Laboratory (LANL) and from nitric acid distillate in the acid recovery process at TA-55, the Plutonium Facility at LANL (ESP-CP TTP AL16C322). This project will develop and optimize the PF technology for specific DOE process streams containing RCRA metals and coordinate it with the needs of the commercial sector to ensure that technology transfer occurs.

  6. Selective removal/recovery of RCRA metals from waste and process solutions using polymer filtration trademark technology

    International Nuclear Information System (INIS)

    Smith, B.F.

    1997-01-01

    Resource Conservation and Recovery Act (RCRA) metals are found in a number of process and waste streams at many DOE, U.S. Department of Defense, and industrial facilities. RCRA metals consist principally of chromium, mercury, cadmium, lead, and silver. Arsenic and selenium, which form oxyanions, are also considered RCRA elements. Discharge limits for each of these metals are based on toxicity and dictated by state and federal regulations (e.g., drinking water, RCRA, etc.). RCRA metals are used in many current operations, are generated in decontamination and decommissioning (D ampersand D) operations, and are also present in old process wastes that require treatment and stabilization. These metals can exist in solutions, as part of sludges, or as contaminants on soils or solid surfaces, as individual metals or as mixtures with other metals, mixtures with radioactive metals such as actinides (defined as mixed waste), or as mixtures with a variety of inert metals such as calcium and sodium. The authors have successfully completed a preliminary proof-of-principle evaluation of Polymer Filtration trademark (PF) technology for the dissolution of metallic mercury and have also shown that they can remove and concentrate RCRA metals from dilute solutions for a variety of aqueous solution types using PF technology. Another application successfully demonstrated is the dilute metal removal of americium and plutonium from process streams. This application was used to remove the total alpha contamination to below 30 pCi/L for the wastewater treatment plant at TA-50 at Los Alamos National Laboratory (LANL) and from nitric acid distillate in the acid recovery process at TA-55, the Plutonium Facility at LANL (ESP-CP TTP AL16C322). This project will develop and optimize the PF technology for specific DOE process streams containing RCRA metals and coordinate it with the needs of the commercial sector to ensure that technology transfer occurs

  7. Trends And Economic Assessment Of Integration Processes At The Metal Market

    Directory of Open Access Journals (Sweden)

    Olga Aleksandrovna Romanova

    2015-03-01

    Full Text Available The article discussed the integration process from the perspective of three dimensions that characterize the corresponding increase in the number and appearance of new relationships; strength, character, and stability of emerging communications; dynamics and the appropriate form of the process. In the article, trends of development of integration processes in metallurgy are identified, identification of five stages of development in Russian metal trading are justified. We propose a step by step way to implement the integration process, developed a methodical approach to assessing the feasibility of economic integration processes steel producers and steel traders, including three consecutive stages of its implementing respectively, the principles of reflexive control, entropy approach, the traditional assessment of mergers and acquisitions. The algorithm for the practical realization of the author’s approach, which allows to identify the optimal trajectory of the integration process as a series of horizontal and vertical integration steps is developed.

  8. Improvement of formability for fabricating thin continuously corrugated structures in sheet metal forming process

    International Nuclear Information System (INIS)

    Choi, Sung Woo; Park, Sang Hu; Park, Seong Hun; Ha, Man Yeong; Jeong, Ho Seung; Cho, Jong Rae

    2012-01-01

    A stamping process is widely used for fabricating various sheet metal parts for vehicles, airplanes, and electronic devices by the merit of low processing cost and high productivity. Recently, the use of thin sheets with a corrugated structure for sheet metal parts has rapidly increased for use in energy management devices, such as heat exchangers, separators in fuel cells, and many others. However, it is not easy to make thin corrugated structures directly using a single step stamping process due to their geometrical complexity and very thin thickness. To solve this problem, a multi step stamping (MSS) process that includes a heat treatment process to improve formability is proposed in this work: the sequential process is the initial stamping, heat treatment, and final shaping. By the proposed method, we achieved successful results in fabricating thin corrugated structures with an average thickness of 75μm and increased formability of about 31% compared to the single step stamping process. Such structures can be used in a plate-type heat exchanger requiring low weight and a compact shape

  9. 2D modeling of direct laser metal deposition process using a finite particle method

    Science.gov (United States)

    Anedaf, T.; Abbès, B.; Abbès, F.; Li, Y. M.

    2018-05-01

    Direct laser metal deposition is one of the material additive manufacturing processes used to produce complex metallic parts. A thorough understanding of the underlying physical phenomena is required to obtain a high-quality parts. In this work, a mathematical model is presented to simulate the coaxial laser direct deposition process tacking into account of mass addition, heat transfer, and fluid flow with free surface and melting. The fluid flow in the melt pool together with mass and energy balances are solved using the Computational Fluid Dynamics (CFD) software NOGRID-points, based on the meshless Finite Pointset Method (FPM). The basis of the computations is a point cloud, which represents the continuum fluid domain. Each finite point carries all fluid information (density, velocity, pressure and temperature). The dynamic shape of the molten zone is explicitly described by the point cloud. The proposed model is used to simulate a single layer cladding.

  10. Characterization of Transition Metal Carbide Layers Synthesized by Thermo-reactive Diffusion Processes

    DEFF Research Database (Denmark)

    Laursen, Mads Brink; Fernandes, Frederico Augusto Pires; Christiansen, Thomas Lundin

    2015-01-01

    . In this study halide-activated pack cementation techniques were used on tool steel Vanadis 6 and martensitic stainless steel AISI 420 in order to produce hard layers of titanium carbide (TiC), vanadium carbide (V8C7) and chromium carbides (Cr23C6 and Cr7C3). Surface layers were characterized by scanning......Hard wear resistant surface layers of transition metal carbides can be produced by thermo-reactive diffusion processes where interstitial elements from a steel substrate together with external sources of transition metals (Ti, V, Cr etc.) form hard carbide and/or nitride layers at the steel surface...... electron microscopy, X-ray diffraction and Vickers hardness testing. The study shows that porosityfree, homogenous and very hard surface layers can be produced by thermo-reactive diffusion processes. The carbon availability of the substrate influences thickness of obtained layers, as Vanadis 6 tool steel...

  11. Prediction Of Formability In Sheet Metal Forming Processes Using A Local Damage Model

    International Nuclear Information System (INIS)

    Teixeira, P.; Santos, Abel; Cesar Sa, J.; Andrade Pires, F.; Barata da Rocha, A.

    2007-01-01

    The formability in sheet metal forming processes is mainly conditioned by ductile fracture resulting from geometric instabilities due to necking and strain localization. The macroscopic collapse associated with ductile failure is a result of internal degradation described throughout metallographic observations by the nucleation, growth and coalescence of voids and micro-cracks. Damage influences and is influenced by plastic deformation and therefore these two dissipative phenomena should be coupled at the constitutive level. In this contribution, Lemaitre's ductile damage model is coupled with Hill's orthotropic plasticity criterion. The coupling between damaging and material behavior is accounted for within the framework of Continuum Damage Mechanics (CDM). The resulting constitutive equations are implemented in the Abaqus/Explicit code, for the prediction of fracture onset in sheet metal forming processes. The damage evolution law takes into account the important effect of micro-crack closure, which dramatically decreases the rate of damage growth under compressive paths

  12. Power characteristics of the metal compounds formation process during the friction stir welding

    Directory of Open Access Journals (Sweden)

    Rzaev Radmir

    2017-01-01

    Full Text Available An influence of the power characteristics on the formation process of the uniform metals compound during the welding with friction stirringis being examined in this article.A dependency between the machine-tool engine power input and the instrument tilt during the FSW for the aluminum alloy AD31, copper alloy M1, titanium alloy OT4-1 and steel St-3 low-alloyed has been explored. A question of the stabilization of power consumption process while the establishment of superplastic condition of welded metal during the FSW has also been reviewed. A dependency revealed between the power characteristics, the geometry of the formation, the rotation speeds, the longitudinal displacement of the tool and its dimensions for fixed values of the parameters during the FSW.

  13. Effect of organosolv and soda pulping processes on the metals content of non-woody pulps.

    Science.gov (United States)

    González, M; Cantón, L; Rodríguez, A; Labidi, J

    2008-09-01

    In this work the effect of different pulping processes (ethyleneglycol, diethyleneglycol, ethanolamine and soda) of tow abounded raw materials (empty fruit bunches - EFB and rice straw) on the ash, silicates and metals (Fe, Zn, Cu, Pb, Mn, Ni and Cd) content of the obtained pulps have been studied. Results showed that pulps obtained by diethyleneglycol pulping process presented lower metals content (756 microg/g and 501 microg/g for EFB and rice straw pulp, respectively) than soda pulps (984 microg/g and 889 microg/g). Ethanolamine pulps presented values of holocellulose (74% and 77% for EFB and rice straw pulp, respectively), alpha-cellulose (74% and 69%), kappa number (18.7 and 18.5) and viscosity (612 and 90 6ml/g) similar to those of soda pulp, and lower lignin contents (11% and 12%).

  14. Cube-textured metal substrates for reel-to-reel processing of coated conductors

    DEFF Research Database (Denmark)

    Wulff, Anders Christian

    This thesis presents the results of a study aimed at investigating important fabrication aspects of reel-to-reel processing of metal substrates for coated conductors and identifying a new substrate candidate material with improved magnetic properties. The eect of mechanical polishing on surface...... texture and the fraction of low angle grain boundaries. Finally, a Ni-5Cu-5W substrate may be a good candidate material as a substrate in future coated conductors....

  15. Numerical simulation of minor actinide recovery behaviour in batch processing of spent metallic fuel by electrorefining

    Energy Technology Data Exchange (ETDEWEB)

    Nawada, H P; Bhat, N P [Metallurgy Division, Indira Gandhi Centre for Atomic Research, Kalpakkam (India); Balasubramanian, G R [Atomic Energy Commission, Mumbai (India)

    1994-06-01

    Numerical simulation of electro-transport of fuel actinides (FAs), minor actinides (MAs) and rare earths (REs) in the electro-refiner (ER) for pyrochemical reprocessing of a typical spent IFR metallic fuel has been attempted based on improved thermo-chemical model developed for application to multi-component system in the ER. Optimization of MA recovery and decontamination factors (DFs) for MAs and REs in batch processing is presented. (author). 7 refs., 4 figs., 1 tab.

  16. Modernity Evaluation of the Machines Used During Production Process of Metal Products

    OpenAIRE

    Ingaldi, Manuela; Dziuba, Szymon T.

    2015-01-01

    Most manufacturing companies realize its technologies, implemented through concrete machinery parts. They differ in terms of importance, the relevance of their selection and the level of their modernity. Modernity and efficiency of the machine are also very important during production process of the metal products. They have an influence on the quality of these products. The purpose of this article is to analyse the chosen production machine (CNC machine AFE-3D8-T) used during pro...

  17. Treatment of uranium-containing effluent in the process of metallic uranium parts

    International Nuclear Information System (INIS)

    Yuan Guoqi

    1993-01-01

    The anion exchange method used in treatment of uranium-containing effluent in the process of metallic parts is the subject of the paper. The results of the experiments shows that the uranium concentration in created water remains is less than 10 μg/l when the waste water flowed through 10000 column volume. A small facility with column volume 150 litre was installed and 1500 m 3 of waste water can be cleaned per year. (1 tab.)

  18. Creep of crystals: High-temperature deformation processes in metals, ceramics and minerals

    Science.gov (United States)

    Poirier, J. P.

    An introductory text describing high-temperature deformation processes in metals, ceramics, and minerals is presented. Among the specific topics discussed are: the mechanical aspects of crystal deformation; lattice defects; and phenomenological and thermodynamical analysis of quasi-steady-state creep. Consideration is also given to: dislocation creep models; the effect of hydrostatic pressure on deformation; creep polygonization; and dynamic recrystallization. The status of experimental techniques for the study of transformation plasticity in crystals is also discussed.

  19. Double layer resist process scheme for metal lift-off with application in inductive heating of microstructures

    DEFF Research Database (Denmark)

    Ouattara, Lassana; Knutzen, Michael; Keller, Stephan Urs

    2010-01-01

    We present a new method to define metal electrodes on top of high-aspect-ratio microstructures using standard photolithography equipment and a single chromium mask. A lift-off resist (LOR) layer is implemented in an SU-8 photolithography process to selectively remove metal at the end of the proce......We present a new method to define metal electrodes on top of high-aspect-ratio microstructures using standard photolithography equipment and a single chromium mask. A lift-off resist (LOR) layer is implemented in an SU-8 photolithography process to selectively remove metal at the end...

  20. Recovery of metals from a mixture of various spent batteries by a hydrometallurgical process.

    Science.gov (United States)

    Tanong, Kulchaya; Coudert, Lucie; Mercier, Guy; Blais, Jean-Francois

    2016-10-01

    Spent batteries contain hazardous materials, including numerous metals (cadmium, lead, nickel, zinc, etc.) that are present at high concentrations. Therefore, proper treatment of these wastes is necessary to prevent their harmful effects on human health and the environment. Current recycling processes are mainly applied to treat each type of spent battery separately. In this laboratory study, a hydrometallurgical process has been developed to simultaneously and efficiently solubilize metals from spent batteries. Among the various chemical leaching agents tested, sulfuric acid was found to be the most efficient and cheapest reagent. A Box-Behnken design was used to identify the influence of several parameters (acid concentration, solid/liquid ratio, retention time and number of leaching steps) on the removal of metals from spent batteries. According to the results, the solid/liquid ratio and acid concentration seemed to be the main parameters influencing the solubilization of zinc, manganese, nickel, cadmium and cobalt from spent batteries. According to the results, the highest metal leaching removals were obtained under the optimal leaching conditions (pulp density = 180 g/L (w/v), [H2SO4] = 1 M, number of leaching step = 3 and leaching time = 30 min). Under such optimum conditions, the removal yields obtained were estimated to be 65% for Mn, 99.9% for Cd, 100% for Zn, 74% for Co and 68% for Ni. Further studies will be performed to improve the solubilization of Mn and to selectively recover the metals. Copyright © 2016 Elsevier Ltd. All rights reserved.