最新刊期
卷 ， 期 5 ， 2006
- 摘要：Thixoforming of pseudo-semi-solid ceramic matrix composites was investigated by combining semi-solid metal forming technology with ceramic matrix composites forming based on powder metallurgy. The satellite angle-frames were made of Al/SiCp composites with different volume fractions of 2Al12 alloy by the new method. The results show that the satellite angle-frames possess a homogeneously distributed microstructure and higher hardness as well as certain plasticity.关键词：Powder Metallurgy;Pseudo-semi-solid Thixoforming;High-melting Alloy;Satellite Angle-frame
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发布时间：2023-12-18 - 摘要：The effects of yttrium on the microstructure and mechanical properties of as-cast and heat treated AZ91D magnesium alloys were examined. Chinese script Al6Mn6Y phase and spheroidized or bar-like Al2Y phase can be observed in the alloy to intensively refine the structure. The mechanical properties of the AZ91D magnesium alloy can be significantly improved by somewhat Y addition, in which the optimized mechanical properties can be obtained with 1.5% Y addition. Furthermore, both the hardness and tensile strength of the AZ91D magnesium alloy containing Y after solid solution treatment are higher than those of the AZ91D magnesium, meanwhile, the Y can postpone the ageing time to delay the time of the ageing peak.关键词：AZ91D Magnesium Alloy;yttrium;Microstructure;Mechanical Properties;Heat Treatment;Hardness
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发布时间：2023-12-18 -
Preparation of Nano-Ni Powder and Nano-Cu Powder by Direct-Current H Electric Arc Evaporation Method
摘要：We have developed a direct-current H electric arc plasma device to systematically research the effects of H/Ar ratio, electric current and pressure on the production rate, structure and spheroidalization of nano-Ni powder and nano-Cu powder by orthogonal testing. The results show that the device not only can prepare nano-Ni powder and nano-Cu powder but also can greatly raise the product rate, where maximum product rate is increased by 24 times for Ni powder and by 203.7 times for Cu powder. Significant orders influencing product rate of two powder is H2/Ar ratio, then current, then pressure, and orders influencing average diameters of Ni powder is H2/Ar, then pressure, then current, and orders influencing average diameters of Cu powder is pressure, then H2/Ar, then current. Both prepared nano-Ni powder ranging in 2065 nm in average diameter and nano-Cu powder ranging in 23141 nm in average diameter are polygonal crystal, where impurities is absent in prepared Ni powder and there exists CuO in prepared Cu powder. Cooling condition in cavity of the device has the important effects on formation and distribution of powder.关键词：Plasma;Nano-Ni Powder;Nano-Cu Powder;Product Rate;Preparation- 2
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- 190
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发布时间：2023-12-18 - 摘要：The isothermal compression behaviors of Mg65Cu25-Y7Nd3 bulk amorphous alloy nearby the glass transition temperature （Tg） and at temperature in the supercooled liquid region are observed. The results show that plastic deformation of Mg65Cu25Y7Nd3 bulk amorphous alloy is closely relative to heating temperature and loading time. The amorphous alloys have some plasticity at 423 K, while it exhibits excellent plasticity at supercooled region. The optimized processing parameters for Mg65Cu25Y7Nd3 bulk amorphous alloy, including heating temperature at 443463 K and loading time for 10min, can be obtained from series experimental data. Microstructural evolution during deformation process shows that compressive deformation can be ignored in effects of crystallized process of Mg65Cu25-Y7Nd3 bulk amorphous alloy.关键词：Bulk Amorphous Alloy;Supercooled Region;Plastic Deformation
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- 231
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发布时间：2023-12-18 - 摘要：The mechanical properties, bending formality and conical cup value （CCV） of AZ31 and ZE10 magnesium alloys were investigated at the temperatures ranging from 20300 ℃. The results show that the tensile strength can be decreased while the plasticity, bending formality and the drawing-bulging performance of the AZ31 alloy and ZE10 alloys can be obviously improved with the increasing in deformed temperature. ZE10 alloy sheets show a better bending formality and drawing-bulging performance compared with AZ31 alloy sheet. When tested at 200 ℃ and 250 ℃, the ZE10 magnesium alloy samples can be drawn into the round hole underside the conical cup with no advents of the fracture.关键词：Magnesium Alloy;Drawing-bulging Performance;Properties
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- 160
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发布时间：2023-12-18 - 摘要：Effects of pouring temperature, rare earth （Pr） modification on the microstructure and properties of as-cast Mg2Si particle reinforced hypereutectic Al-Si alloy in-situ composites prepared by liquid-melting casting were examined. The results show that the composites with uniform and fine grain size can be prepared by pouring at 720 ℃ nearby liquidus temperature. RE modifier can effectively refine the primary Si phase and eutectic structure while refine size and change morphology of the Mg2Si particle, obviously improving the mechanical properties of the alloy and postponing the modification time.关键词：Mg2Si;Hypereutectic Al-Si Alloy;In-situ Composites;Microstructure
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- 364
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发布时间：2023-12-18 - 摘要：The mechanical properties, microstructure and electric performance as well as their fracture morphologies were investigated by SEM for beryllium bronze （QBe2） and chromium bronze （QCr0.5） and aluminum bronze （QAl9-4） after solid solution treatment. The strength and electric performance of the three heat treated alloys can be improved, in which QBe2 possesses the best elasticity and QCr0.5 has the best electric performance, and the performance of QAl9-4 is located between those of the oher alloys. Fracture morphology shows that QBe2, QCr0.5 and QAl9-4 are ductile fracture, near to brittle fracture and quasi-cleavage fracture, respectively. QBe2 can be substituted for QCr0.5 for elastic electrical components under the conditions of low elasticity and low electric resistance requirement, while QAl9-4 is not suitable for elastic electrical components.关键词：Cu Alloy;Solution and Ageing Treatment;Microstructure and Properties
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- 340
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发布时间：2023-12-18 - 摘要：Shrinkage porosity and gas （pin） hole formed in localization of alloy manifold result in the low qualified product rate. A model for the manifold was established to simulate the flow and solidification during filling process, and commercial MAGMAsoft software was employed to analyze the flow field and temperature field to predict the possible position formed shrinkage porosity and entrapped gas during filling process. Based on above results, the countermeasures were adopted to increase the qualified rate from about 20% to 93%, including introducing exhausting tube and enlarging riser.关键词：Casting;Numerical Simulation;Defects;Manifold
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- 167
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发布时间：2023-12-18 - 摘要：A casting management system including parameterized, block library and graph database was developed based on practical product combining AutoCAD graph database with casting processing parameter access database. The system can meet the requirements of practical product.关键词：Management System of Casting Graph;Access Database;Parameterized Graph Library
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- 90
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发布时间：2023-12-18 - 摘要：Effects of pouring!temperature and holding time on microstructural evolution of semi-solid AlSi9Mg magnesium alloy were analyzed. It is found that with increasing in holding time, microstructure is converted from dendrite to rosette and then to spheroidized grain. The required fine and uniform spheroidized non-dendrite microstructure can be created with holding time for 3040 min at 605℃.关键词：Holding Time;AlSi9Mg Alloy;Non-dendrite Structure;Pouring Temperature;Semi-solid
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- 143
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发布时间：2023-12-18 - 摘要：Effects of extrusion deformation on microstructure and properties of Mg95Zn4.3Y0.7 alloy were investigated at 250 ℃ with different extrusion ratios. The results show that the eutectic phase in the boundary of the extruded alloy is broken up to dispersively distribute into grain, obviously refining the grain size. Meanwhile, with increasing in extrusion ratio, the mechanical properties of the extruded alloy are improved due to grain refinement. With extrusion ratio of 16, results was observed such as grain size of 58 μm, tensile strength of 288.9 MPa and micro-hardness of 117.8.关键词：Mg95Zn4.3Y0.7 Alloy;Eutectic Structure;Deformation
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- 111
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发布时间：2023-12-18 -
Die Casting Mould with Pumping Crossed Cores by Crossed Compound Dog-led Cams and Hydraulic Pressure
摘要：The design of mechanism pumping crossed cores is a difficult point in die casting moulds. A die casting die with pumping crossed cores by crossed compound dog-led cams and hydraulic pressure is used for cupulate parts with inboard concave. Cupulate core, which is hollow core, was set on the moving die to create the inner-wall of cupulate parts, in which concave core and small dog-led cam were assembled, where crossed compound dog-led cam was linked by small dog-led cam with large ones fixed on the container. Hollow core was linked with hydraulic loose-core implement fixed on the moving die. The opening force of die casting machine drives the crossed compound dog-led cam mechanism draw core in inboard concave, and then make the hydraulic loose-core implement to draw the hollow core.关键词：Crossed Compound Dog-led Cams;Hydraulic Loose Core;Crossed Core;Loose Core on Inboard Concave;Die Casting Die- 2
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发布时间：2023-12-18 - 摘要：Aiming at the structure features and technological requirements for EA111 aluminum alloy oil tank, an available design plan for die casting die was described. The large end-face was selected as parting face and inner-drawing-core mechanism was used for the die casting die. Meanwhile, heating oil and heating machine were used to control the temperature of the die, and slide-slot was used to guide slide block. Vacuum-drawing system was assembled to eliminate the gas hole, which improved the quality of the parts.关键词：Oil Tank;Die Casting Die;Gas Hole;Inner Drawing-core Mechanism;Heating Machine
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- 153
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发布时间：2023-12-18 - 摘要：Automobile variator back-shell with large dimension is a complicated die-castings where there are several side-hole and exist narrow-long rib and convex at outsides. Five-directional structure was adopted in design of die casting die, in which a departed structure was used for moving die design, including main core and top-core, and declined columniation parting and hydraulic drawing-core mechanism were used for forming of side-core. The horizontal cold chamber die casting machine with closed force of 6 300 kN has been selected by calculating filling pressure.关键词：Die Casting Die;Side-parting;Moving Die and Container;Die Structure
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- 170
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发布时间：2023-12-18 - 摘要：The BH-1 type low pressure casting control system was developed based on framed-structure. The running effects from practical production in many years indicate that the control system based on framed-structure not only decreases difficulties in development and the subsequent maintenance cost, but also makes the system stable, reliable and easy to maintain.关键词：Framed-structure;Low Pressure Casting;Computer Control
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- 101
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- 2
发布时间：2023-12-18 - 摘要：The structure optimization design for six kinds of typical investment casting parts was conducted based on the principle of six “by hook and by crook”, and CAE software was employed to verify the optimized effects. It is found that some defects encountered in the parts can be eliminated, including scab, inflation, bleeding from parting, shrinkage porosity, crack, by reducing large end face, and by avoiding deeply-long channel as well as using reinforced ribs, which improved the quality of the investment casting parts.关键词：Investment Casting;Casting Structure;Optimization Design
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发布时间：2023-12-18 - 摘要：The characteristics of art castings in lost foam casting were expounded. The procedures of copper bell in lost foam casting were described in detail. The superiority to manufacturing middle-large art casting in lost foam casting is presented.关键词：Art Castings;Lost Foam Casting;Copper Bell
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- 181
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发布时间：2023-12-18 - 摘要：The design of permanent mould for piston in MAZDA620 was introduced. CAE was used in design and manufacturing of the permanent mould, and the filling process was simulated. The rational measures were employed to avoid the possible defects including gas hole and cold shut in the mold, such as assembling airway and properly improving mould temperature and alloy temperature. So the mould can meet the requirements of applied technology, and desirable castings can be produced.关键词：Aluminum Alloy;Piston;Permanent Mould;Gravity Casting;CAD/CAM/CAE
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- 81
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发布时间：2023-12-18 - 摘要：Based on the technological features of cylindrical cover, the top gating system was used with 610s pouring time at 730740 ℃, in which different coatings were employed in different location, and different core-making processes in different cores, meanwhile sand-removal at high temperature was used in sand-cleaning. The practical verification shows that the qualification rate keeps about 90%.关键词：Cylindrical Cover;Core-making;Gating System;Cleaning
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- 238
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发布时间：2023-12-18 - 摘要：The formation of crack in metal mould larger-plane thinned-wall aluminum alloy parts with deep-cavity was analyzed for oil tank.The defects are attributed to the alloy solidified characteristics and thermal stress and cotraction stress of the parts during solidification.The defects are eliminated success fully by controlling chemical composition of the alloy,enhancing refinement （pouring temperature of 710 ℃）,dispersively inducing pouring,controlling die temperature above 300 ℃,adjusting thickness of the coating and reinforcing solidified orders.关键词：Thinned-wall;Deep-cavity;Large Plane;Metal Mould Casting;Crack;Countermeasures
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- 303
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发布时间：2023-12-18 - 摘要：The evolution of as-cast microstructure of eutectic Mg-Al alloy with different Ce addition is observed by simulating the components of addition the alloy in the late solidification. The results show that liquid Ce can remarkably change the microstructure of the alloy, where the primary α phase is increased and the β phase is refined and inhibited. The desirable microstructure with 0.6% Ce addition can be observed, while in turn, with Ce addition more than 0.6%, the refinement effects is inferior with Ce addition increase.关键词：Eutectic Mg-Al Alloy;Modification;RE Ce;Solidification Structure
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- 305
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发布时间：2023-12-18 - 摘要：Effects of melting conditions and Al-5Ti-1B master alloy additions on P modification ZL109 piston alloy were investigated, focusing on the effect mechanism. The appropriate Al-5Ti-B master alloy addition can obviously refine primary Si in the Al-Si alloy in main frequency furnace while can be ignored in electrical resistance furnace. However, excessive Al-5Ti-B master alloy addition can coarsen the primary Si phase in the alloy in both electric resistance furnace and main frequency furnace. EPMA analysis indicates that there exists enriched-Ti in center of the primary Si phase in the modified alloy. It is concluded that the adsorption of TiB2 particle to AlP site can be responsible for the modification effects of Al-P master alloy.关键词：Al-Si Alloy;Al-5Ti-B Master Alloy;primary Si;Modification
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- 166
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发布时间：2023-12-18 - 摘要：Based on combination of the comparison test results with production site validation method, the Si content fluctuation has been analyzed for A356.2 alloy in the L type tower melting furnace during a smelting. The reason of Si content fluctuation has been revealed from the viewpoint of Si segregation. The results show that during a special melting period, the regular fluctuation of Si content in the liquid alloy is attributed to the difference flow resulting from the special L type melting structure of the tower melting furnace, which validates the existence of difference in Si content in the liquid alloy in L type tower melting cincture and in the holding furnace. Based on the above mentioned results, the effective evaluation and countermeasures have been proposed.关键词：L Type Tower Melting Cincture;Constituent Segregation;Mechanism;Countermeasures
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发布时间：2023-12-18 - 摘要：Compared with conventional thick-walled copper parts, it is more difficult to produce the abnormal thick-walled copper parts in casting technology, which often lies on the amounts of practical experiences and CAE analysis. For some typical parts, including housing, bracket base, coil, T type broad sheet, the casting processes,have been proposed. Based on the analysis of typical parts, the design principle of casting processes for abnormal thick-walled copper parts are approached.关键词：Copper Alloy;Abnormal Thick-walled Parts;Casting Process;Solidification Simulation
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发布时间：2023-12-18 -
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