最新刊期
卷 ， 期 2 ， 2007
- 摘要：Effects of Si, Ba and Sn element on the as-cast microstructure of AZ91 magnesium alloy have been observed. The results show that although trace Si addition can refine the grain size of AZ91 magnesium alloy, 0.5%Si addition can result in the creation of coarse Chinese script Mg2Si phase in the alloy. Coarse Mg2Si particles can not be observed with adding minor Ba into AZ91 magnesium alloy containing 0.5% Si, which is attributed to the formation of Al4Ba phase in the alloy. Trace Sn addition can refine the grain size of the alloy due to the creation of Mg2Sn phase with a high melt point, where β-Mg 17 Al 12 phase is converted from net-like structure into disperoids with 0.50% Sn addition. And 0.50% Sn addition can increase solid solution degree in Al atom.关键词：AZ91 Magnesium Alloy;Si;Ba;Sn;As-cast Microstructure
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发布时间：2023-12-18 - 摘要：After smelting preheated tin ingot which is delivered into melting furnace by delivery roll, the first connector was employed to deliver the liquid tin from the bottom of melting furnace to the holding furnace, where the liquid surface in the melting furnace is 100200 mm higher than that in holding furnace. Furthermore, the second connector was used to deliver the liquid tin from the bottom of holding furnace to the prilling furnace, where the liquid surface in holding furnace is 3050 mm higher than that in prilling furnace. Through using above measures, the round and sound and pollution-free tin prill with clean surface and uniform distribution can be successfully prepared, which has been applied for electroplating tin steel plate.关键词：Short Flow;Tin Prill;Casting;Electroplating Tin
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发布时间：2023-12-18 - 摘要：The effects of Sb addition on the microstructure and mechanical properties of Mg-4Al-2Si alloy have been examined. The results show that 0.2%0.75% Sb addition can obviously refine Chinese script Mg2Si particles and matrix α-Mg phase, and create Mg3Sb2 phase in the alloy, improving the mechanical properties of the alloy, where Mg2Si particles can be greatly refined with 0.25%Sb addition and fine and homogeneousα-Mg equiaxed grain can be generated with 0.75% Sb addition to obtain maximum tensile strength and yield strength. With Sb addition more than 0.75%, the mechanical properties can be dramatically deteriorated, which is as a result of segregation and coarse of amounts of Mg2Si particles towards grain boundary.关键词：Mg-4Al-2Si Magnesium Alloy;Sb;Mg2Si Particles;Mechanical Properties
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发布时间：2023-12-18 - 摘要：Zr 41 Ti 14 Cu 12.5 Ni 10 Be 22.5 bulky metallic glass （BMG） was prepared by shock-wave quenching generated from high temperature and high pressure by high speed impaction of driving flying plate using double-level light artillery. The prepared BMG samples are different in structure, thermal stability and properties compared with that of prepared alloy samples by water-quenching due to the comprehensive effects of shock-wave on molten alloy, having higher glass transition temperature and crystallization temperature, lower density and higher acoustic speed, which shows that shock-wave quenching is a promising method for preparation of BMG.关键词：Bulky Metallic Glass;Shock-wave Effects;Glass Transition
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发布时间：2023-12-18 - 摘要：We have developed a system suitable for rapidly measuring hydrogen content in magnesium alloy melt by using computer and controlled circuit based on a mathematical model for measurement of hydrogen content in magnesium alloy to measure hydrogen content in AZ91 magnesium alloy. The results show that hydrogen content in AZ91 magnesium alloy is 614 cm2 per 100 g in the condition of gas protection, increasing with temperature increase.关键词：Magnesium Alloy Melt;Hydrogen Content;Mathematical Model;Hydrogen-measuring Apparatus
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发布时间：2023-12-18 - 摘要：TiO2 composite film containing P and Ca was prepared on surface of medical Ti materials by microarc oxidation with constant voltage. The effects of anode voltage on the morphology, phase constituent and Ca, P content in the oxide films were investigated by SEM, XRD and EDS, focusing on the Ca and P content disposition regularity in the oxide film surface and in intra-pore. The results show that the composite film is composed of mini-pore and anatase TiO2 phase with lower P and Ca contents as well as Ca/P ratio, in which the Ca and P contents in the mini-pore are lower than ones in film surface with low anode voltage treatment. The mini-pore, the volume number of the rutile TiO2 and the Ca and P contents as well as Ca/P ratio are increased with the increase of anode voltage. Ca and P contents in mini-pore is equivalent to ones in the film surface in case of high anode voltage treatment. The Ti oxidization reaction can be effectively promoted with increasing constant voltage. After MAO （micro-arc oxidation）, Ti surface porous morphology, phase constituent and Ca, P contents would have an important effect on the formation of hydroxyapatite in hydrothermal synthesis treatment.关键词：Micro-arc Oxidation;Ti;TiO2 Composites Film;Anode Voltage;Ca
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发布时间：2023-12-18 - 摘要：The temperature field and flow field of molten aluminum alloys during degassing and purification process by rotary impeller have been simulated by a computational model. The results indicate that a special pipeline fixed into the rotate pole can remarkably decrease the temperature in the rotate pole and prevent the spinning rotor from jamming resulting from spray flux softening at high temperature. The rotate speed and the flux have the important effects on the degassing and purification of molten aluminum alloys, so appropriate parameters should be considered according to the actual situation. With square furnace, the gas got out in the vertical section along shaft on the cross, while the volume fraction of the gas can be decreased remarkably in vertical section along shaft, even exhibiting hydrogen inhalation.关键词：Liquid Aluminum Alloy;Spinning Rotor;Degassing;Simulation
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发布时间：2023-12-18 -
- 摘要：The 3-dimensional flow and temperature field as well as turbulent flow models were established to simulate the liquid metal onflow of outer shell high speed steel during filling and liquid-solid bonding of roll core and shell metal based on the practical experimental data, observing the effects of pre-heating temperature of roll core on solidification and liquid-solid bonding. The results show that the molten high speed steel is progressively solidified from underside and two-side interfaces to upper and midst in the mold, however, the solidification characteristics are different with the preheating temperature variation of roll core. With lower pre-heating temperature, the end-solidification position lies in the middle of shell metal while it lies in the interface of shell metal and roll core with the higher preheating temperature at the same sections. The shell can tightly bond with the core to form the compound roll with proper preheating temperature, however, the metallurgical bonding can not be found with the lower preheating temperature for the core. The optimized preheating temperature of the core is about 1 1001 200 ℃.关键词：Compound Rolling;Casting;Filling;Solidification;Numerical Simulation
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发布时间：2023-12-18 - 摘要：Based on the large non-linear finite element software MSC.Marc, the three-dimensional thermodynamic coupled mathematical and physical models were built up, in which the thermal profile and the elastic deformation of the roller have been considered. Based on the high-temperature flow change constitutive formula and the thermal contact conductance computation model, the complicated boundary conditions and the heat contact conditions were established to conduct secondary development of the Marc using the Fotran language. The curves of roller’s shape in steady rolling-casting conditions have been mapped in case of uneven inlet temperature filed by visualizing practical production, which is well in agreement with practical result’s.关键词：Continuous Rolling-casting;Three-dimensional Thermodynamic Couple;Marc Finite Element;Thermal Profile of the Roller;Elastic Deformation of the Roller;Inlet Temperature
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发布时间：2023-12-18 - 摘要：The compression deformation behavior of semi-solid Y112 aluminum alloy manufactured by semi-solid isothermal treatment has been examined by means of Gleeble-1500 thermal-mechanical simulator in the conditions of different deformation temperatures and different deformation rates. It is found that when the compression strain is less than 0.8, compression stress of semi-solid aluminum alloy is firstly rapidly increased then rapidly decreased with the increase of compression strain. The maximum compression stress of semi-solid aluminum alloy can be observed with the compression strain approximately 0.07 at both different deformation temperaturse and different deformation stresses. In addition, the compression stress can be increased with decreasing in deformation temperature or increasing in deformation rate.
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发布时间：2023-12-18 - 摘要：We have developed a contour rotary viscometer to investigate steady apparent viscosity of hypereutectic ZL117 alloy. The results indicate that with the decrease of holding temperature, that is the increase of solid fraction, the steady apparent viscosity of the alloy slurry is increased. With the increase of stirring rate, the steady apparent viscosity is firstly decreased to the minimum value at about 14A, then increased. In addition, the steady apparent viscosity of the alloy slurry can be improved with raising the cooling rate.关键词：Hypereutectic Al-Si Alloy;Semi-Solid Slurry;Rheological Property;Steady Apparent Viscosity
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发布时间：2023-12-18 -
- 摘要：Aiming at easy formation of crack and contract in the process of die casting, the selection of parting surface and gating system design was paid attention to by analyzing the structure features of thin-walled lampshade for car light with complicated shape and deep cavity. Based on above analysis, Pro/E software was used to create die cavity and die core as well as gating system and push mechanism, and the design of whole die assemble was completed successfully.关键词：Lampshade;Die-casting Die;Parting Surface;Gating System;Pro/E Software
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发布时间：2023-12-18 -
- 摘要：Aiming at the characteristics of structure and performance of pump body in high pressure gear pump, squeezing casting was employed to manufacture the pump body, and the optimized die structure parameters and processing parameters were provided. It was feasible for manufacturing gear pump by direct squeezing casting. The leakage of the manufacrured gear pump can not be found at the pressure of 25 MPa, and the blast pressure is more than 60 MPa, saving more than 15% materials.关键词：Gear Pump;Squeezing Casting;Die Structure
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发布时间：2023-12-18 - 摘要：Link spraying manipulator for die casting machine was designed, in which the relevant structure parameters were optimized. The designed manipulator can be available for spraying die with different shapes and thickness as well as different sizes and thickness of parts. The structural optimization of the manipulator has been conducted by means of a mathematical software based on the linear weighting method, which was verified by attached program.关键词：Structure Design;Manipulator;Parameter Optimization;Die Casting
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发布时间：2023-12-18 -
- 摘要：It is difficult to cast the radiatior with air-tightness requirements in investment casting.Through analysis of structure of the radiator,some countermeasures,including design of gating system,filling velocity,pouring temperature of shell mold,super-heating of liquid steel,were conducted to improve the air-tightness of radiator and to decrease welding-repair,increasing the qualified rate of the investment casting radiators.关键词：Design of Gating System;Air-tightness;Pouring Temperature;Feeding
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发布时间：2023-12-18 - 摘要：Key designing point and noted items on processing of plate and ring parts in investment casting have been described, and designing regularity of multi-hot spot and multi-risers as well as series of countermeasures based on the above regularity have been approached. Riser-ring, ring module as well as how to improve the yield rate of these investment castings were introduced.关键词：Plate and Ring Investment Castings;Hot Spot;Riser-ring and Ring Module
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发布时间：2023-12-18 - 摘要：Wear-resistance of Ti-48Al-2Cr-2Nb prepared by metallic mold centrifugal casting was tested in the conditions of casting and hot isostatic press （1 270 ℃/173 MPa/4 h）. Experimental results reveal that the friction coefficient of as-cast samples is bout 0.140 with loading of 50 N for 10 min or loading of 100 N for 5min, while the friction coefficient of HIP treated alloy sample is about 0.158 with loading of 50 N for 10 min or loading of 100 N for 3 min. The microstructural observation indicates that the influence of HIP on friction coefficient of TiAl based alloy is attributed to eliminating shrinkage porosity in the samples to improve the compactness of the alloy and to convert the structure of the alloy from full laminar into duplex-structure.关键词：TiAl Base Alloy;Centrifugal Casting;HIP （Thermal Isostatic Press）;Friction Coefficient
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发布时间：2023-12-18 -
- 摘要：We have developed a continuous molding device to produce manganess series ferroalloy with low strength and high brittleness on the basis of analyzing physical properties of the alloy. Cu mould inlayed graphite sleeve was used in the device, which can reduce the friction resistance between the ferroalloy alloy and the mould due to the self-lubrication effects from graphite, and vertical drawing as well as eccentric wheel realizing sine vibration was used also, to ensure the successful preparation of the manganess series ferroalloy in continuous casting.关键词：Mould （crystallizer）;Mangnaness Series Alloy;Frictional Resistance;Graphite
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发布时间：2023-12-18 - 摘要：The lost foam technology in the Europe and the U.S.A, including the present status of development was overviewed based on the relevant content of the 4th symposium on lost foam casting in Paderbon. The developing trend of lost foam casting was also expounded. The symposiums have four themes as follows: first, international LF market; second, design and manufacture of LF mould; third, construction and research; forth, research and application of LF. It can be concluded that great progress has been made in the investigation of the mould filling of aluminum alloy and LFC technology for magnesium alloy, and in lost foam materials and in the new methods for lost foam casting with high quality surface, and in the role of pattern permeability.关键词：Lost Foam Casting;Aluminum Alloy;Magnesium Alloy
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发布时间：2023-12-18 - 摘要：The origination of casting defects in the forehand plate of air-conditioner compressor for car in shell mold method was analyzed. The casting defects can be effectively eliminated by optimizing gating system, conducting secondary inoculation for liquid Fe and adjusting content and controlling the chemical composition of liquid Fe, to greatly improve the quality of the forehand plate.关键词：Shell-mold Method;Gating System;Forehand Plate;Phy-chemical Properties
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发布时间：2023-12-18 -
- 摘要：Effects of heat treatment on microstructure of aluminosilicate short fiber reinforced ZL108 composites prepared by squeezing casting have been observed. The results reveal that the heat treatment can improve the microstructure of the composites. With increasing in holding time, the grain size in the microstructure of the composites becomes finer and finer. In addition, the creation of new phase in the heat treated composites can be found with increasing in heat treated temperature and cooling rate , which is attributed to the increase of cooling rate resulting in the decrement of eutectic growth temperature.关键词：ZL108 Alloy;Aluminosilicate Short Fiber;Composites;Heat Treatment;Cooling Rate
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发布时间：2023-12-18 - 摘要：Al2O3/Cu composites were prepared by internal oxidation of Cu-Al sheet at 900 ℃ to investigate the microstructure and properties of the composites, in which the Cu2O powder was used as oxidizer. The results indicate that the Al2O3 particles are dispersively distributed in the diffusion zone. The grain size in surface and inner of diffusion zone is sharply different, finer in the surface than in the inner. The micro-hardness of surface of diffusion zone can be improved due to Al2O3 disperoids strengthening Cu matrix. Compared with solid soluted Al atom in Cu matrix, the Al2O3 disperoids has slightly affected the electron diffraction, resulting in the increase of electric conductivity after Al2O3 precipitation. With increase of deformation rate of Al2O3/Cu sheet in case of cold working, the tangle of Al2O3 disperoids with dislocation becomes worse and worse.关键词：Al2O3/Cu Composites;Internal Oxidation;Electric Conductivity;Micro-Hardness
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发布时间：2023-12-18 -
- 摘要：Stirring friction welding was employed in the butt welding of the 7075 Al alloy with 8mm thickness in single pass. The desirable joint with tensile strength of 390 MPa can be achieved with the rotating speed of stirring joint at 1180r/min and welding speed at 37.5 mm/min, which is 78% of that of the matrix materials. The microstructure of the joint exhibits typical stirring friction joint structure, consisting of fine equiaxed grain with size of 67μm and finding the absence of enhancing phase in the welding nugget. Micro-hardness of the joint is symmetrically distributed along the welding line, however, the micro-hardness of TMAZ/HAZ transition zone and welding nugget zone is lower than that of the matrix materials, which should be the weak zone of the welds.关键词：Friction Stirring Welding;Microstructure;7075 Aluminum Alloy;Butt Welding
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发布时间：2023-12-18 -
- 摘要：The electrolytic Al-Si-Ti alloy （AST） and the electrolytic low Ti aluminum base alloy （LTA） were produced by two methods in the industrial electrolytic tank. SE（B） specimens of ZL101A alloy obtained by above two alloys have been prepared to observe the fatigue crack propagation of the AST alloy and LTA alloy. Two key parameters in the Paris formula and critical value can be given by fitting representative data points in one set data obtained by testing fatigue crack propagation rate on a MTS 810 material machine. The results show that compared with ZL101A alloy prepared by AST, the ZL101A alloy prepared by LTA exhibits better anti-fatigue crack propagation behavior, which is attributed to higher Fe content in AST alloy deteriorating the anti-fatigue crack propagation. Therefore, either decreasing Fe content or modifying Fe in the AST alloy can improve the anti-fatigue crack propagation behavior of AST alloy.关键词：Electrolytic Al-Si-Ti Alloy;Electrolytic Low Ti-Al Base Alloy;Stress Concentration Factor Range;Fatigue Crack Propagation Rate;Critical Value
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发布时间：2023-12-18 -
- 摘要：It is an necessary procedure to wash the workpiece with mixed acid before the spiral vibration polishing, however, the mechanism of acid pickling can not be well understood. The composition and roughness of the surface of aluminum alloy samples before and after acid pickling were examined by X-ray photoelectron spectroscopy （XPS） and contour measure apparatus. The results show that major Si phase in surface of aluminum alloy samples is dissolved by acid to form Al2O3 film with higher roughness after acid pickling, which is cut by the succedent spiral vibration polishing to form a more smooth and bright polished surface.关键词：Acid Pickling;XPS;Roughness;Al-Si Alloy;H2SiF6
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发布时间：2023-12-18 - 摘要：The microstructure of Ti 51.7 Ni 24.5 Cu 23.8 shape memory alloy ribbons prepared by rapid solidification has been observed in the conditions of spinning and annealing respectively. The results show that microstructure of as-spun ribbons is mainly composed of amorphous phase embedded with a small amount of crystalline particles that is indexed by B2 or B19. B19 martensites variants show various morphologies such as needle, coarse plate, strip and hook. The initial crystallization temperature of 436 ℃ can be observed and the crystallization activation energy of 444.7 kJ/mol of the as-spun ribbons can be determined by the Kissinger’s equation at a heating rate of 5 ℃/min by DSC linear scanning. Crystallization structure of the ribbon is mainly composed of single-pair variant B19 martensites, in which there exist two pairs of variants self-accommodated with perpendicular orientation in some particle, and the absence of the hook-like martensite variants can be found and new martensite is preferred to nucleate at the grain boundary to growth towards grain, with annealing at 400 ℃.关键词：Rapid Solidification;Ti-Ni-Cu Alloy;Ribbons;Microstructure
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发布时间：2023-12-18 - 摘要：The gas hole often can be generated in Cu alloy propeller containing Al, Mn,Ni elements due to the formation of absorption-gas during smelting, which is mainly relevant to the alloy composition, smelting process, drying level of mould. The gas-hole in the Cu alloy propeller can be effectively eliminated by some countermeasures, such as degassing in ladle, increasing preheating temperature of mould.关键词：Cu Alloy;Gas-hole;Propeller
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发布时间：2023-12-18 - 摘要：The resistance against the aging for matrix phase in Cu-24Al-3Mn-2Ti alloy has been tested by bending test, X-ray diffraction, optical metalloscope and SEM and TEM in the conditions of different aging for matrix phase. The results indicate that with a given strain, shape memory effects （SME） are firstly decreased then increased with increasing in holding temperature, in which the desirable SME can be observed at 400 ℃ and the most un-desirable SME can be found at 500 ℃. The SME can exhibit first increase then decrease with increasing in holding time, which shows slow decrease at 400 ℃ and somewhat rapid decrease at 500 ℃. The microstructure of the alloy can be refined with the Mn and Ti addition due to the creation of Mn-enrichment and Ti-enrichment phase, which can strengthen the microstructure and improve the SME of the alloy.关键词：Strain;Aging for Matrix Phase;SME;Holding Time;Holding Temperature
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发布时间：2023-12-18 -
- 摘要：The shape memory effects and mechanical properties of β-Cu based shape memory alloy can be badly deteriorated by high elastic anisotropy factors and large grain size, which can heavily obstruct industrial application. Based on above reasons, a single crystal furnace and crystallizer were designed to prepare single crystal Cu-Al-Be and Cu-Al-Ni alloy, in which the effects of grain boundary is relieved. The novelty of the apparatus is that the crystallizer goes through the furnace from the upper to bottom to ensure stabilization of single crystal growth. The experimental results verify that the self-designed single crystal directional furnace has successfully prepared single crystal Cu-Al-Be shape memory alloy.关键词：Shape Memory Alloy;Single Crystal;Cu-Al-Be Alloy;Cu-Al-Ni Alloy
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发布时间：2023-12-18 -
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