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By Kandipati Sreenivasarao

Ion flotation is a promising separation process for continuously removing toxic metal ions from dilute process effluents. After treating the effluent with appropriate surfactant(s), the metal- bearing species adsorb onto the surface of rising gas bubbles and can be collected as foams. Suitable collectors have been identified for most of the elements of the periodic table. However, a better understanding of the thermodynamic, kinetic and engineering principles that determine the performance of ion flotation systems would facilitate commercial utilization of this technology. A model system of sodium dodecylsulfate-ethanol has been studied for the removal of Cu (11) from dilute solutions, using laboratory-scale flotation columns. This paper reports the effects of the air flow rate, solution height, foam drainage zone height and col1ector:metal ion ratio on the flotation kinetics, ultimate recovery of metal, flotation product grade, foam losses and effluent quality. Preliminary results for Pb (11) removal are also reported.

Jan 1, 1993

By Krzyszof Borowiec

With the aim of determining the thermodynamic conditions for sulfation of impurity elements, in particular magnesium, in titaniferous slags the equilibrium gas composition for the sulfation reaction: MO + so2 + 1/2 02 = MS04 has been studied by an EMF technique with a solid zro2 + Cao electrolyte. Here M denotes the impurity elements: Mg, Ca and Mn, and the following _oxide systems have been studied: Ti02-MgO-Fe2 o 3 , Ti02-MnO-Mn2 o 3 , and Ti02 -CaO-Si02 , all in the . temperature range 700-1000ºc. Reproducible EMF values were obtained by adding small amounts of -Na2so4 to the oxide-sulfate mixture. From the observed results the Gibbs energy of formation of the phases Mg 2Ti04 , MgTi03 , MgTi 2o 5 , MnTi03 , CaTi03 , and CaTiSio5 , as well as the activity of MgTi05 in the solid solution with Fe2Ti05 have been calculated. The results show that, from a thermodynamic viewpoint, sulfation of these impurities in titaniferous stags i:s favorable- at around and below 800ºC.

Jan 1, 1985

By Norihisa Iida, Yutaka Koshiba, Tsutoipu Masui

"Mitsubishi Materials has many years of experience in the production of oxygen free copper (OFC) and its alloys with a fully continuous-casting process. Four grades of OFC, commercial, electronic, superconductor, and ASTM class I are available according to user needs such as stabilizer for superconductivity, magnetron, and ultra-vacuum systems. Along with Cu-Ag and CuSn, we offer OFC based copper alloys such ·as Cu-Cr-Zr, Cu-Fe-P, Cu-Ni-Si and others, that are suitable for lead frame and connectors. Within the maximum sizes of 260mm X 1050mm for cakes and 385mm diameter for billets, we are very flexible and can adjust the ingot size to customer’s requirements. Other products that we can supply are semi-finished products such as hot rolled sheet, ·forged blank, extruded rod and finished products like mold for continuous casting of steel, ring mold for non-ferrous casting and backing plate for sputtering target.IntroductionMitsubishi Materials Corporation developed mass produced high quality oxygen free copper and. high copper alloy ingots in the 1960's. We produce 60,000 - 70,000 tons annually giving us 22 - 23% share of the world's market.Our oxygen free copper and. copper alloys are produced with a fully continuous casting process using only high-grade copper cathodes from our Naoshima and Onahama refineries. The raw material is melted and cast in' a carefully controlled atmosphere resulting in a product with low impurities and excellent properties.Using a controlled atmosphere it is possible to produce high quality copper alloys including active elements like chromium (Cr), zirconium (Zr), titanium (Ti), and magnesium (Mg) which are difficult to produce using standard batch casting methods.Using our own cakes and ·billets we produce and supply worldwide wrought materials like molds for ferrous and non-femous casting. These products receive special patented thermo-mechanical· treatments resulting in high strength and excellent conductivity with low cost."

Jan 1, 2000

By H. Kung, T. R. Jervis, M. Nastasi, T. E. Mitchell

"A systematic study of the structure-mechanical properties relationship is reported for nanolayered composites of MoSh-SiC, Mo-MoSh, Mo-MoShNx, MoSi2-MoSi2Nx, and Mo-MoShMoSi2Nx (x=3-4) synthesised by sputtering techniques. These composites have been studied by nano-indentation and cross-sectional TEM as a function of annealing temperature. As-deposited layers are amorphous except for Mo. With increasing annealing temperature, first MoSh and then SiC crystallize, while the hardness progressively increases until the layers start to spheroidize and grain growth sets in at 900ºC. For the case of Mo-MoSi2, the layers react and the composite deteriorates rapidly. However, MoSi2Nx remains amorphous up to 1000ºC, suggesting that it could act as a diffusion barrier between Mo and MoSi2. In fact the Mo. MoSi2Nx, MoSi2-MoSi2Nx and Mo-MoSi2-MoSi2Nx nanolayers are found to remain stable up to such temperatures. IntroductionMolybdenum dislicide, MoSh, is a potential matrix material for high temperature structural composites due to its high melting point and good oxidation resistance at elevated temperature [1]. The two major drawbacks for structural applications are inadequate high temperature strength and poor low temperature ductility. Silicon Carbide (SiC) being hard and thermally compatible with most ceramics and intermetallic compounds, has been found to be suitable for second phase reinforcement in various structural applications and, in particular, the addition of SiC whiskers improves the high temperature yield strength of MoSi2 [2]. While most of the research in MoSb-SiC composites has been on the particulate form of SiC, laminated composites may offer unique properties. It has been shown that synthetic multilayers with alternating layers of metal and/or compounds may exhibit interesting mechanical properties [3]. Enhancement in mechanical properties by decreasing the wavelength of multilayer spacing has been studied extensively. In general, two types of strengthening have been proposed: (1) Hall-Petch strengthening [4,5], where the strength increase is inversely proportional to the square root of the layer thickness; (2) Koehler modulus strengthening [6], which increases with modulus difference and decreasing layer thickness. In the present study, we have performed a systematic study of the relationship between strength and structure in a number of different nanolayered systems based on MoSh. Layer thicknesses have been varied and their nanostructures have been varied by heat treatment. Previous work on MoSi2-SiC is summarized [7]. In an attempt to improve fracture toughness, MoSh-Mo nanolayered materials have been prepared but are found to react and deteriorate. Previous work has shown that nitrided MoSi2 (MoSi2Nx with x=3-4) is highly stable [8] and so nanolayered composites of MoSi2-MoSi2Nx and Mo-MoSi2-MoSi2Nx have been prepared to assess the' stability and mechanical properties of these composites. Preliminary results are presented."

Jan 1, 1994

By K. Gao, R. Dry

"Carbon boil, which results in excessive spitting and even complete destruction of a metal drop, could significantly influence the efficiency of direct smelting processes. Carbon boil has been studied as a function of some key parameters such as melt sulfur content, oxygen partial pressure, and melt area/volume ratio. The time of carbon boil was determined using a CCO camera coupled with a time/date generator connected in parallel to a video recorder and a computer. The time of carbon boil was in the range ~5 - 15 seconds under the conditions in this study. A mechanism for carbon boil has been proposed.IntroductionThe occurrence of carbon boil in molten iron drops can result in excessive spitting and sometimes even complete destruction of a metal drop. In direct iron smelting processes, this could significantly influence the decarburisation of liquid metal and the post combustion and hence may influence the efficiency of smelting processes. The generation and consequent ejection of metal droplets into the gas phase occurs due to the intense turbulence in the bath which results from the injection of gases and coal. The aim of this investigation is to understand the fundamentals governing the carbon boil phenomenon under direct iron smelting conditions to assist control of process efficiency.Carbon boil phenomenon has been studied as a function of some key parameters such as melt sulfur content, oxygen partial pressure and melt area/volume ratio. The time for the occurrence of carbon boil has been determined in this study at 1440 °C using a novel approach which includes utilisation of a CCD camera coupled with a time/date generator connected in parallel to a video recorder and a computer. This arrangement permits the capture of the entire sequence of events leading up to carbon boil and therefore the determination of time of boil which is in the range -5 - 15 seconds under the conditions in this study."

Jan 1, 1996

By X. K. Lan

The greater demand for high-quality large-diameter crystals has led to the robust idea of a free- flying solar-powered furnace satellite, whereby the buoyancy-driven convection effects are almost nonexistent, and diffusion-controlled crystal growth with minimal radial segregation is promoted. In the proposed solar furnace, a paraboloid of revolution imaging concentrator is used to focus the sun's radiation onto an-ampoule which holds the solid charge to be processed. The charge will start melting in the vicinity of the focal point, after which it is translated in order for the melt to resolidify as a single crystal. A ray-trace method has been developed to determine the incident concentrated solar heat flux on the ampoule surface for a perfectly-aligned configuration with an incoming columnated beam. A transient 2- dimensional conduction problem with phase change is formulated, which is solved using the commercial code FIDAP. Results highlighting the feasibility of growing GaAs, Ge and Si crystals with diameters of the order of 20 cm using the solar furnace satellite concept are presented. The transient temperature fields within various charge materials are quantified.

Jan 1, 1994

By Kouji Mimura, Manabu Kishida, Minoru Isshiki

"Purification of metallurgical grade silicon (MG-Si) by the plasma-arc zone melting method (PZM) has been examined. The process consisted in the horizontal displacement of a molten zone heated by Ar- and 10%H2+Ar- plasma-arc under atmospheric pressure. This technique, especially using hydrogen plasma-arc, promoted the segregation of impurities from the head to the tail of the bar and the vaporization of impurities of higher vapor pressures. Metallic impurities such as Fe, Ti, Cr, Mn,. Cu, Al and Ca were reduced to less than 1 mass ppm at the head side of the Si bar. Non-metallic impurities such as boron, phosphorous, carbon and oxygen were also reduced by the zoning effect and, furthermore, by activated hydrogen atoms dissociated in the high temperature plasma-arc according to the following reaction: Q (in liq.Si) + 2H = H20. Plasma-arc zone melting with hydrogen plasma has been recognized to become an effective purification technique of MG-Si for the production of a low cost solar grade Si (SOG-Si).IntroductionDemand of high-purity Si for solar grade silicon (SOG-Si) is supposed to be further growing in the near future. The purity of SOG-Si required for the photovoltaic cell is more than six nines. An expensive semiconductor grade silicon (SEG-Si) with the purity of around eleven nines has been used to satisfy the demand. Development of techniques and processes for the production of a low cost SOG-Si is therefore necessary [l]. Although many purification techniques, such as directional solidification, plasmaarc melting and electron beam melting [1-6], and processes, such as carbothermic reduction of high purity silica [7], have been examined and proposed for this purpose, a more efficient and practical purification technique is still required.In the present work, the purification of MG-Si has been investigated using a plasma-arc zone melting (PZM) technique developed by the authors. Plasma-arc melting, which is well· known as a useful melting method for various metals and alloys, has been recognized to be efficient for refining and degassing several metals if hydrogen is added to the plasma generating gas, resulting in the so-called hydrogen plasma-arc. For example, deoxidation of Fe, Co and Ta [8,9], decarburization of Fe [9] and removal of metallic impurities from Zr, Ta and Fe [10-12] have been reported. This excellent refining effect is considered to be caused by dissociated and activated hydrogen atoms formed in the high temperature plasma-arc."

Jan 1, 2000

By Patrick R. Taylor

This investigation studied the inflight calcination kinetics of nuclear waste simulant using a thermal plasma reactor. A series of experiments were performed to determine the conversion of insoluble aluminum compounds to the soluble compounds and the decomposition of complex organic and nitrite compounds present in the simulant waste. Thermodynamic calculations based on free energy minimization were performed to establish a theoretical basis for this investigation. A kinetic model to describe the conversion of gibsite to sodium aluminate has been proposed. The products of the calcination were characterized using XRD, Gas Chromatography, and chemical analysis by ICP. The results of this investigation indicated 85% gibsite conversion to sodium aluminate, 90% of nitrate decomposition, 52% TOC decomposition and 90% conversion of chromium to soluble compounds. A process is identified for inflight calcination of wastes. Key words: Plasma, waste, simulant, calcination

Jan 1, 1996

By Stein Tore Johansen

Some ferro-silicon furnaces have heat-recovery equipment. Here, the recovery of electric energy from the off-gases can be increased by increasing the off-gas temperature. This is easily done by reducing the amount of air which usually is mixed into the?off?gas to cool the gas mixture. If the off-gas becomes too hot problems with severe fouling or clogging of the gas channels close to the furnace is observed. The result is irregular stops to clean the off-gas channels. The paper focuses on the nature of the clogging phenomena and some of the ways to avoid clogging. A detailed experimental study was carried out at the Elkem Thamshavn Plant. Theoretical studies were performed to understand the particle deposition, turbulent multiphase fluid flow and off gas combustion in the off-gas channels. The study has resulted in reduced clogging.

Jan 1, 1992

By Alain Jardy, Thibaut Quatravaux, Denis Ablitzer

"A numerical model of the Vacuum Arc Remelting process has been developed and applied to simulate remelting of various metallic materials, such as specialty steels, titanium and zirconium alloys. In practice, electromagnetic stirring is sometimes used, resulting in a complex 3D molten metal flow. After having validated the numerical model for different remelting conditions, we can use it to study the effect of applying a constant or alternated magnetic field on the thermohydrodynamic behaviour of the melt pool. The intensity of flow turbulence, computed with a classical k-E model, is shown to depend strongly on the nature of electromagnetic stirring.IntroductionThe principle of the Vacuum Arc Remelting (VAR) process, illustrated in figure I, consists in melting a consumable metallic electrode of the required grade under a high vacuum, in order to obtain a sound ingot of good structural quality.During remelting, an electric arc is maintained between the tip of the electrode and the top of the secondary ingot, in order to ensure melting of the electrode. The metal droplets fall through the arc plasma and progressively buid up the ingot, which solidifies in contact with the walls of a water-cooled copper crucible. The secondary ingot formed in this way contains three distinct zones, corresponding to the liquid pool, fully solidified metal and intermediate mushy zone. In order to stabilize the arc, it can be confined with the aid of a magnetic field created by an external induction coil. This field can also be used to stir the liquid metal, the rotation induced being in the orthoradial direction. By reversing periodically the coil current, stirring can be alternated."

Jan 1, 2004

By C. F. Ferron

A process has been developed to treat the copper gold ores from the Guelb Moghrein mine in Mauritania. The process consists of pressure leaching the sulphide concentrate, neutralising with the oxide ore, recovery of copper by SX/EW and of gold by cyanidation of the autoclave residue. This paper focuses on the pressure leaching step, and presents data from bench and pilot plant test programs. In particular, attention is drawn to the effects of temperature, grind size, neutralisation, retention time and solution recycle on the kinetics of copper dissolution from various flotation concentrates. Likely leach mechanisms are briefly discussed.

Jan 1, 2000

By Xiangru Chen, Qijie Zhai, Wei Zhang, Haicheng Li, Chao Yang

In this paper, ductile iron material with different content of niobium was prepared by a scientific melting method. Image Analysis Software was used to studied the effect of niobium microalloying on both pearlite content and pearlite lamellar spacing in ductile iron quantitatively. The results showed that the addition of a small amount of niobium could increase the pearlite content and decrease pearlite lamellar spacing of ductile iron effectively.

Jan 1, 2015

By L. Katgerman, E. N. Straatsma, Suyitno

"Single-roll strip casting process is studied using computational fluid dynamics which takes into account fluid flow, heat transfer and solidification. The computational model is based on the conservation Jaws of momentum, energy and continuity. Correlation of strip thickness, solidification zone length, and puddle shape on single-roll strip casting of Al-1 %Mn is explored. Feeding pressure and roll speed are investigated. The results show that the··strip thickness slightly increases with pressure, similarly the length of solidification zone. The variations of strip thickness and solidification zone length with roll speed show a sharp decline for strip thickness and slight decline for the length of solidification zone with increasing roll speed. The constraint and free-jet flow have different feature in term of flow field. Severe turbulence is observed on the free-jet flow.IntroductionThe near-net shape casting of strip metals is a demand nowadays. The demand is particularly stimulated by the challenge to become more competitive through enhanced performance. The improvement in the existing processes and new innovative technologies are introduced by the metal industry to gain better product quality, more efficiency in energy consumption, low throughput, yield and operating costs [1-3].There are many advantages that can be obtained by the direct casting of strip. The most prominence is the elimination of hot rolling. Beside that the high rate of heat extraction associated with strip casting offers the possibility of a finer, Jess segregated cast structure. The microstructure will result in the improvement of mechanical properties compared to conventional material, or alternatively the opportunity of using grades of metal outside the normal range for continuous casting.The concept of single-roll strip casting has been difficult to commercialize, because of the complex interactions between fluid flow, solidification, shrinkage, and stress, which lead to serious quality problems. Besides that, the quality and the thickness of the strip are affected by the thermal properties of the strip, roll cooling conditions, roll geometry, and other process parameters. To understand how these parameters affect the strip formation, some researchers have modeled the process [4]."

Jan 1, 2004

By H. H. Law

Large amounts of waste material in the form of flue dust are generated in the operation of copper smelter furnaces. As a result of increasingly stringent disposal, it has become important to develop methods for treating such metallurgical wastes to extract metals and convert them into salable products. A two-step closed-loop hydrometallurgical process, has been developed: (1) extraction with sulfuric acid removes about 90% of zinc and decreases the dust volume by 50%; (2) extraction with hydrochloric acid dissolves the lead and further decrease the dust volume by 75%. A process scheme for generating salable products is proposed.

Jan 1, 1992

By Sridhar Seetharuman

Sulfur and oxygen dissolved in nickel and cupronickel melts can be removed as gaseous oxides of sulfur by a vacuum treatment. Presented in this paper is a new matched thermochemical diagram that permits direct evaluation of the equilibrium partial pressure of SO, as a function of temperature over an alloy of specified composition. The matched thermochemical diagram consists of a central plot which shows the integral Gibbs' energy of mixing for the binary system S-O2, at different temperatures. The central plot is flanked on either side by terminal plots of the chemical potentials of oxygen and sulfur, as functions of temperature, for different alloy compositions. By projecting the chemical potentials of oxygen and sulfur from the terminal plots on to the central diagram, the equilibrium pressure of SO2,can be directly read on the nomograms on the central plot at different temperatures. The matched thermochemical diaerams are - useful in assuring the efficiency of vacuum refining.

Jan 1, 1993

By Soumitro Nagpal

Bacterial oxidation of a pyrite-arsenopyrite-gold ore concentrate was carried out in .14-liter continuous-flow stirred-tank reactors (CSTR). Oxygen and carbondioxide consumption rates mineral dissolution rates, and bacterial concentrations were measured at various steady-state residence times and with 6, 11, and 16 wt.% solids in the feed slurry. A sharp optimum in biooxidation rate .was found at a residence time of approximately 40 hours for operation at each of the three pulp-densities. Biooxidation rates increased consistently. with increasing pulp density. Cell washout accompanied by negligible biooxidation rates was found to occur at a residence time of approximately 20 hours. Mineral' oxidation was found to be strongly dependent on bacterial activity. Arsenopyrite was found to be preferentially oxidized? at the higher Pulp densities.

Jan 1, 1991

By Yuri Gelfgat

"This paper presents some results of the investigation of the steady magnetic field influence on hydrodynamics and heat/mass transfer in processes of semiconductor single crystal growth (Si, Ge, InSn). The investigation employed mathematical and physical simulation techniques of relevant processes and full-scale experiments on growth facilities. A number of additional MHD phenomena have been found generated in the melt due to the rearrangement of flow pattern, the formation of specific convective cells, and the origin of MHD boundary and shift layer.IntroductionMagnetohydrodynamic (MHD) means of creating forces by contact-free methods in liquid conducting media have been widely used in the production of volume semiconducting single crystals. The goal of this method is to control convective transfer processes in the melt volume and on the crystallization front [1-3]. This is due to the sufficiently high conductivity of semiconductor melts (s = 104 /106 O1m-1 ) and an obvious relationship between the hydrodynamics in the melt and at interfaces and the conditions of formation of single crystals and their quality [ 1].All types of MHD effects rest upon the generation of volume electromagnetic forces in the melt by various means as well as on the possibility to direct them arbitrary in space and to adjust easily their absolute values. Fig. l presents different means how to implement MHD phenomena during single crystal growth. It should be emphasized that in all the modifications given in Fig. l additional energy introduced into the melt cannot influence directly the crystallization process since it is incomparable to the energy of molecular forces. Both the influence and efficiency of MHD means are determined solely by the change of motion, heat and mass transfer characteristics."

Jan 1, 1998

By Behrouz Abedian, Livia M. Racz

"We address dynamic interactions between high-energy, reactive surfaces of polymer-matrix composites and solid surfaces. A common characteristic of these interfaces is that bonding occurs readily upon contact. In many industrial and biomedical applications, it is desirable to suppress this bonding phenomenon. This interfacial effect is discussed in light of the development of our new method of handling polymer-matrix composites in dental applications. This method involves vibration of the solid-polymer interface at different frequencies. For each material, there is a critical frequency at which the sum of the viscoelastic and inertial energies of the fluid at the surface exceeds the energy available for bonding. When the polymer is vibrated at or beyond this frequency, it does not adhere to solid surfaces. An important aspect of the developed process is that it can be used to characterize surface and interfacial properties of polymers under dynamic conditions, whereas existing techniques are restricted to the study of bulk dynamic properties.IntroductionThe purpose of this paper is to report on the development of a new method for manipulating polymer-matrix composite materials used in dental applications, and the potential of this process for use in materials characterization. The materials under discussion have polymer matrices of a combination of bisphenol A-glycidyl methacrylate (BIS-GMA) and triethylene glycol dimethacrylate (TEGDMA), and contain filler particles of silica and/or zirconia glasses. These materials are called direct aesthetic restorative materials, and are used for filling of cavities, repairing chipped teeth, and for other restorations in which appearance is of importance. They have the appearance of natural tooth material, and are therefore in great demand for use in the anterior portion of the mouth(l,2)."

Jan 1, 1998

By Robert W. Bartlett, Keith A. Prisbrey

"Natural biooxidation of shallow, refractory ore heaps, relying on gaseous oxygen diffusion from the heap surface is attractive because of its simplicity and potential low cost, especially without using a lined pad, which is possible if percolation of leachate through the heap is avoided. In this case, the excess oxidation enthalpy must be removed by water evaporation from within the wet ore heap, and the rising water vapor flux within it will impede the downward oxygen flux. An analysis of this process shows that for typical values of pyrite grades and limited temperature increases in the ore heap, the oxidation rate and penetration into the heap is reduced to values between about 30 percent and 50 percent of those obtained when leachate percolation occurs and water evaporation is not a significant mechanism of heat removal.IntroductionHeap biooxidation of refractory gold ores, needed as a pretreatment step to liberate the gold for subsequent extraction by leaching, requires large amounts of oxygen for the normal amounts of sulfide minerals that are typically present, one to two percent pyrite and/or arsenopyrite.The importance and potential limitations of oxygen transport into commercial ore heaps, which are much larger than encountered with column tests of ore and with pilot heaps, has been recognized111 • Commercial ore heaps using radial stacking conveyors are typically about nine meters high and may be 100 meters or more in lateral dimension. Three oxygen transport mechanisms have been identified and analyzed: ( 1) natural convection, which arises from an increase in buoyancy caused by the temperature rise and gas composition changes associated with the exothermic oxidation of the sulfide minerals within the ore heap, (2) forced air ventilation, using low pressure fans and air distribution pipes within the heap, and (3) diffusion of oxygen in the gas-filled void spaces within the ore heap driven by the oxygen concentration gradient from the surface of the heap to the mineral oxidation loci within it."

Jan 1, 1997

By Roderick I. L. Guthrie, Donghui Li, Mihaiela Isac, Luis Calzado

The HSBC is an ideal process for the production of BMG strips. The purpose of the present work was to investigate the casting of Ca-based, bulk amorphous strips. The possibility of casting three Ca-based alloys (60Ca-20Mg-20Al, 60Ca-15Mg-10Al-15Zn and 55Ca-15Mg-10Al-15Zn- 5Cu (at.%).) was investigated, using the HSBC simulator. Numerical simulation and mathematical modeling were used to predict temperature variations and cooling rates, under different interfacial gaseous atmospheres (helium and air) near the meniscus region. Given the critical cooling rates and glass temperatures needed to be reached for the vitrification of the respective alloys, this leads to predictions of the critical thicknesses possible with this novel casting process. To validate our predictions, these alloys were then prepared and cast onto the sand-blasted, solid copper substrate mould of the HSBC simulator. The possibility of producing Ca-based metallic glassy strips via the HSBC processes was confirmed, using optical microscopy, X-ray diffraction and Scanning Electron Microscopy, to characterize the glassy properties of the cast strips. It was found that the HSBC process would be able to provide sufficient cooling to form amorphous strips for the 60CA-15Mg-10Al-15Zn and 55Ca-15Mg- 10Al-15Zn-5Cu alloys, but not the 60Ca-20Mg-20Al alloy.

Jan 1, 2014