最新刊期
卷 ， 期 1 ， 2005
- 摘要：Metal-gas eutectic directional solidification （Gasar） ia a novel technology for preparing lotus-type metals with oriented pores parallel to the solidification direction. We developed a Gasar apparatus to have successfully prepared lotus-type porous Mg samples. Effects of technological parameters, including preheating temperature of cast mold and gas pressure, on gas-hole rate, gas-hole size and gas-hole distribution in the lotus-type porous Mg were investigated. The results indicate that gas holes in metal shell can be eliminated by the increase of the preheating temperature of cast mold. Average diameters of the ingot decrease with hydrogen pressure increase.About 8% hydrogen is overflowed during the total Gasar solidification.关键词：Porous Metal;Eutectic;Directional Solidification;Lotus-type Structure
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发布时间：2023-12-18 -
- 摘要：Ultra-fine crystalline Fe 76B 12Si 12 alloy with a diameter of 16 mm, a height of 15 mm and average grain size of about 120 nm, whose magnetic losses of P 400 1t and P 1000 1t are 40% and 65% of those of conventional silical-steel sheet respectively, were successfully prepared by quenching high under-cooled samples in water.Influences of constituent structure and Fe 2B（Si） phase size on the soft magnetic properties of the alloy are examined. It is found that the optimum soft magnetic properties of the alloy occur in the microstructure zone with second anomalous eutectic and completely granularized Fe 2B（Si） phase.Furthermore, the soft magnetic properties can be significantly improved with the phase size reduction when fined Fe 2B（Si） phase size is less than 0.36～0.50 μm. The mechanism was approached also.关键词：Fe 76B 12Si 12 Alloy;High Under-Cooled;Ultra-fine Crystalline Materials;Solidification Microstructure;Soft Magnetic Properties
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发布时间：2023-12-18 -
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- 摘要：Magnetic flux density distribution of traveling magnetic field generator used for electromagnetic casting and its action on the melt were investigated. The results show that magnetic flux density in z and y direction （B z and B y） varies inversely.Existence of B z results in pit defects in surface during mold filling.Although B z can obviously accelerate the melt flow velocity to improve the ability to filling mold, section of the melt front is decreased to take converse filling mold, resulting in cold shut defects. The surface quality can be improved by ferromagnetic up-mold via enhancing B z and weakening B y. The pulling force exerted on metal from magnetic field is related to the projective area of metal on the inductor. The metal cannot be moved even in the existence of electromagnetic force with the projective area less than a critical projective area.关键词：Electromagnetic Casting;Magnetic Flux Density;Mold Filling;Defect
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发布时间：2023-12-18 - 摘要：A new forming method,the ceramic matrix composites thixoforming in pseudo-semi-solid state,was presented based on the powder metallurgy in combination with the semi-solid metal forming and the developing direction of the ceramic forming in the 21st century. The angle-frames were produced by the method with SiC p as the matrix materials and 30Al as the plasticization phase.The results show that the component’ microstructure with 6.43 GPa Hv and about 0.5% strain stress as well as about 300 MPa tesile strength is homogeneously formed. It will play a very important role in promoting the application of the ceramic matrix composites and high melt point materials in more fields.关键词：Powder Metallurgy;Pseudo-semi-solid;Thixoforming;SiCp Composites
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发布时间：2023-12-18 - 摘要：The microstructure and properties of 3% particulate TiC reinforced bearing steel matrix composites prepared by electroslag smelting-casting method were examined. The results show that the composites possess the characteristics of small porosity and high soundness. The un-changed TiC particulate is uniformly distributed into the steel matrix and the Fe 3C compound is formed in the crystal boundary. The wear experiment show that the wear-resistance of the composites are higher than that of the steel matrix.关键词：Electroslag Smelting-casting Method;TiC Particulate;Microstructure;Wear
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发布时间：2023-12-18 - 摘要：In-situ Mg 2Si/Mg composites were fabricated by conventional gravity casting based on the crystallization characteristics of Mg-Si binary alloy,focusing on the effects of Sb on morphology of Mg 2Si enhancing phase in the composites. The results show that addition of 0.8% Sb into Mg-10Si alloy can not only promote homogeneous nucleation of Mg 2Si enhancing phase but also restrain the further growth of Mg 2Si enhancing phase because of the segregation of Sb at the interface. Consequently, morphology of Mg 2Si enhancing phase transformed from coarse dendrite into uniformly dispersed particulate and Mg 2Si particulate reinforced Mg matrix composites with desirable microstructure are obtained.关键词：Mg-Si Alloy;Mg 2Si/Mg Composites;Microstructure;Sb;Modification
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发布时间：2023-12-18 -
- 摘要：Desirable WC particle reinforced HT300 matrix composites with the thickness of about 6 mm in compound layer were prepared by cast-infiltration in V-EPC, in which WC particles were distributed into the compound layer. Liquid Fe infiltrated into compound layer while a little Cr infiltrated into the matrix during cast-infiltration process. Alloying layer and the matrix belong to metallugirical bonding. The hardness of the composite decreases from the compound layer to matrix and the average hardness of the compound layer increases by about three times over that of the HT300 matrix materials.关键词：Fe Matrix Surface Composites;Cast-Infiltration;V-EPC;Hardness
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发布时间：2023-12-18 - 摘要：A fully coupled model was developed to describe the temperature field, solute field and turbulent flow field in continuous casting process, which was used to predict the solidification of the thin slab and the formation of the macrosegregation. The results show that injection flow from the submerged entry nozzle impacts the narrow face of the crystallizer to divide into upper and lower backflows. The turbulent flow has a significantly effects on heat transfer and solute transfer. The macrosegregation is formed in central area of the billet resulted from the continuous enrichment of solute during solidification process. The solute transfer model of Schneider is employed to predict the effects of the counter diffusion on the distribution of solute in the mushy zone and solid phase.关键词：Thin Slab;Continuous Casting;Solidification;Numerical Simulation;Macrosegregation
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- 509
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发布时间：2023-12-18 - 摘要：Interaction CAD system for die casting dies was developed by visual basic （VB） program conducting sub-development of AutoCAD. In the system the parametrized method and module mehod were effectively combined. Only if several basic parameters of the diecasting parts are input in the system, the design of the whole of die casting die can be completed and the corresponding part drawing can be output so that the die casting die design is high efficient and faster.关键词：Die Casting Die;CAD;Parametrized Design;Visual Basic
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- 113
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发布时间：2023-12-18 -
- 摘要：Research status of strengthening mechanism of crystallization of alloy materials in squeezing casting was introduced briefly. Aluminum, zinc, magnesium alloys and their composites in squeezing casting were approached. It is pointed out that the rational squeezing casting technology can refine microstructure and improve the component compactness as well as the mechanical properties of alloy.关键词：Squeezing Casting;Aluminum Alloy;Zinc Alloy;Mg Alloy;Composites
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发布时间：2023-12-18 - 摘要：RE giant magnetostrictive TbDyFe alloy bar with high surface quality and uniform chemical composition can be prepared by a gradient directional solidification equipment at super-high temperature. Compared with an electric arc furnace, the gradient directional equipment has the features of low investment for equipment, simple operation and accurate control for chemical composition as well as the completion of smelting and directional solidification of TbDyFe alloy bar in equipment one step. The chemical composition analysis indicate that the burning losses of Tb and Dy in normal smelting are less than 2% and 3% respectively.关键词：Directional Solidification;Smelting and Casting;TbDyFe Alloy;Bar
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发布时间：2023-12-18 - 摘要：The brief development history and dominant factors of forming ability of bulk amorphous alloys were surveyed. The forming mechanisms of bulk amorphous alloys were investigated from the viewpoints of thermodynamics, kinetics and structure. The criteria for bulk amorphous alloys design were introduced. It was pointed out that,molten metal having high density random close-packed topology structure, restraining the homogeneous nucleation and nuclei growth of the supercooled melt as possible, increasing the cooling rate and reducing or eliminating heterogeneous nucleation,would be helpful to form bulk amorphous alloy.关键词：Bulk Amorphous Alloys;Dominant Factors;Forming Mechanism;Alloy Design
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- 705
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发布时间：2023-12-18 - 摘要：Die casting Mg alloy for crankshaft house and wheel of motorcycle were investigated systemically. The results show that application of diecasting Mg alloy in motorcycle can be realized by analyzing the component service condition and failure type,establishing a component service model and analyzing service condition, redesigning the structure based on alloy performance, optimizing the simulation of production process and production of Mg alloy component as well as measuring the operation performance.关键词：Die Casting;Mg Alloy;Crank House
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- 179
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发布时间：2023-12-18 -
- 摘要：The structures and mechanical properties of the ZL112Y Al alloy kickstand of generator in JH70 motorcycle in thixoforming were examined. The experimental results show that the parts without inner void and shrinkage porosity can be heat-treated. Compared with the machanical properties of the parts in conventional die casting, the maximum tensile strength, average values of tensile strength, yield strength, elongation and hardness HRB of the parts in semi-solid thixo-die casting increase by 60.10%, 50.83%, 41.52%, 514.29%, 12.41% respectively.关键词：ZL112Y Aluminum Alloy;Semi-solid Thixo-Casting;Heat Treatment;Microstructure;Mechanical Properties
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发布时间：2023-12-18 - 摘要：Casting defects, including misrun, shrinkage hole, shrinkage porosity and deformation of radiator often appear in initial production of cylinder cover of FG sand bus. The defects can be significantly reduced or eliminated by increasing blade thickness and reducing pressure for elevating liquid metal,so as to improve the sound parts rate.关键词：Misrun;Shrinkage Hole;Shrinkage Porosity;Deformation;Casting Defects
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发布时间：2023-12-18 - 摘要：Recycled waxes were used not only to make ingate but also to widely press wax pattern for civil and commericial investment castings in USA and Europe since the 1990 s.Recycled waxes by holding deposition at home cann’t meet the requirements of wax performance,especially dramatical superscale in ash content.Multilevel filtration-purification system is the key technology in recycled-refreshed wax.Recycled-refreshed wax with qualifed ash content,softening point and viscosity can be used to produce the pattern.关键词：Recycled-refreshed Wax;Filtration-purification System;Ash Content
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- 139
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发布时间：2023-12-18 -
- 摘要：The properties, including bending strength, linear contraction, thermal stability, melting point and ashes content, of the PW-1 type pattern materials with the organic macromolecular polymer Px as additive at different injection temperatures were measured.The microstructures of pure wax and PW-1 pattern material were observed. It was indicated that compared with pure wax, PW-1 pattern materials possess 3.65 MPa bending strength, 0.76% linear contraction, 37 ℃ thermal stability,0.008% ashes content at 57～59 ℃ homogeneous grain size and fine microstructure,optimization comprehensive properties are realized.关键词：Investment Casting;Pattern Materials;Microstructure;Properties
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发布时间：2023-12-18 - 摘要：The phase compositions of unbaked shell waste, baked shell waste,poured shell waste of conventional sodium silicate ceramic shell and silica sol ceramic shell waste were analyzed respectively.Some approaches to recycle ceramic shell waste were proposed.关键词：Investment Casting;Ceramic Shell;Waste;Recycle
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发布时间：2023-12-18 - 摘要：The vorticity compressor parts were manufactured by the V-EPC process. Compared with the parts by green sand process, the parts by the V-EPC process have vorticity line near to the finished parts and clear profile have the features of fine and sound microstructure, which can significantly reduce the production cost and save raw materials. The possible defects encountered in production and their solution method were reviewed.关键词：V-EPC;Vorticity Compressor;Casting Defects
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发布时间：2023-12-18 - 摘要：By analyzing the casting defects in aluminum alloy blade, it is pointed out that the casting defects are closely relative to pouring position, gating system design, exhaust of the mold house and the mold filling temperature. Based on the mentioned analysis, some improvment methods, including mold tilt, horizontal pouring and vertical cooling, design of exhaust gutter along the parting surface, changing in thickness of coating layer and adjustment of solidification sequence,are presented.关键词：Defect Analysis;Large Aluminum Alloy Blade;Permanent Mold Casting
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发布时间：2023-12-18 - 摘要：We developed a Al5Ti0.25C master alloy to refine the AlMg10 alloy. The results show that the Al5Ti0.25C master alloy can significantly refine the AlMg10 alloy. Average grain size can change from 650 μm to 71μm with 0.2% addition of Al5Ti0.25C for 5 min at 670 ℃,which realizs a optimized refinement effects.关键词：AlTiC;AlMg10;TiC Particle;Grain Refinement
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发布时间：2023-12-18 -
- 摘要：A new cast copper alloy with excellent comprehensive mechanical properties of σ b≥550 MPa ,σ 0.2≥280 MPa,δ 5≥18% and a excellent corrosion resistance to seawater used for seawater pumper and valves was developed. In the seawater with a velocity of 7 m/s, the errosion rate of the alloy is 0.042 mm/a while in the sand-contained seawater with a velocity of 3.5 m/s, the errosion rate is only 0.144 mm/s. The difference of corrosion potentials between the developed alloy and （10/90） Cu-Ni alloy used for widely the seawater pump and valves is less than 100mV with a galvanic corrosion rate of 0.009 2 mm/a, which can effectively restrain galvanic corrosion of seawater pump and raise the service life of the pump and valves. Compared with other conventional copper for seawater pump and valves, the alloy subjeted to higher pressure possesses higher tensile strength and yield-strength ratio so that it can be widely used for the fields, such as deep-sea engineering.关键词：Copper Alloy;Ni-Al Bronze;Sea-water Errosion;Sea-water Pump;Seawater Valves
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发布时间：2023-12-18 -
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