最新刊期
卷 39 ， 期 9 ， 2019
- 摘要：The crack propagation behavior of Ti/TiC laminated composites was investigated based on the extended finite element method（XFEM）.The accuracy and effectiveness of the simulated results were verified by comparing with the existing experimental ones.The results show that Ti/TiC laminated composites exhibit layer by layer fracture characteristics,and the crack propagation is advanced in form of Z shape.In the crack propagation process,the crack propagation will be deflected,which increases the path of crack propagation and absorbs more amounts of the fracture energy,therefore the fracture toughness of the material is increased remarkably,and make the material with higher safety and stability.When the load reaches 336.7 N,the first crack initiation occurs at the Ti layer,and the maximum principal stress is 3 048.65 MPa,which leads to the absence of composites failure.The second crack of the material occurs at the TiC layer when the load value reaches 392.5 N,and the maximum principal stress reaches 4 557.54 MPa,which leads to the composites failure.关键词：Laminated Composites;XFEM Method;Fracture Mechanics;Crack Propagation
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发布时间：2023-12-18 - 摘要：The effects of RE on the fluidity,mechanical properties and microstructures of Al-Si-Cu alloys were investigated by metallographic,scanning electron microscopic analysis,X-ray diffraction,liquidity and tensile test.The results show that the fluidity and mechanical properties of Al-Si-Cu alloy can be enhanced and the grain size can be refined by adding proper amount of RE.Al-Si-Cu alloy has the desirable modification effect with the RE content of about 0.4%,where the fluidity and tensile strength,elongation of alloy are increased by about 24%,9.4% and 35%,respectively,after aging treatment,the tensile strength and elongation are increased by 8.4 and 26%,respectively.关键词：RE;Al-Si-Cu Alloys;Fluidity;Mechanical Properties;Microstructures
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发布时间：2023-12-18 -
High Temperature Compression Deformation Behavior and Microstructure Evolution of TC4 Titanium Alloy
摘要：High temperature thermal simulation single direction compression experiment was carried out with Gleeble-3500 thermal/mechanical simulation testing machine at varied deformation parameters deformed temperature and strain rate.The true stress-true strain curves obtained were analyzed to understand effects of deformed parameters on flow stress and compressive microstructure of TC4 alloy during single direction compression process.Through observing microstructure of deformed samples,the recrystallization and recovery state of the TC4 alloy were analyzed during high deformation process.The results reveal that flow stress is increased rapidly and then decreased gradually to be stable with increasing in strain.With increasing in deformation temperature,grain boundary is broken increasingly,and strip-like structure is decreased,meanwhile,secondaryαphase in the structure is increased gradually.关键词：TC4 Titanium Alloy;High Temperature Compression;Deformation Behavior;Microstructure Evolution- 2
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发布时间：2023-12-18 - 摘要：Microstructure and hardness of ZGCr17Ni2 martensitic stainless steel were treated at different solution temperature and tempering temperature.The results show that the supersaturation of martensite and the content of retained austenite are increased with the increase of quenching temperature.The microstructure is composed of martensite+retained austenite+carbide+ledeburite at 1 040℃.and the hardness reaches the maximum value of 57 HRC.Increasing in quenching temperature,martensite is coarsened and hardness is decreased.When tempering temperature is below 530℃,the tempering hardness is changed in saddle shape.The tempering microstructure is transformed into tempered sorbite+retained austenite+carbide+ledeburite+martensite,and the tempering hardness is decreased to 41 HRC with the tempering temperature reaches of 600℃.关键词：Martensitic Stainless Steel;ZGCr17Ni2;Heat Treatment Process;Microstructure;Hardness
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发布时间：2023-12-18 - 摘要：The effects of Ni and Y contents on the microstructure and mechanical properties of Mg100-3xNixY2x（x=0.5,1.0,1.5,2.0%）alloys reinforced with Long Period Stacking Order（LPSO）structure were analyzed.The results show that with the increase of Ni and Y contents,the primaryα-Mg grains in the alloys is refined and the volume fraction of LPSO structure is increased from 10% to 40%.Eutectic Mg2Ni phase exists in Mg94Ni2Y4 alloy due to the excessive Ni element.The tensile strength of the alloys is increased with the increase of Ni and Y contents,while the elongation is decreased continuously.关键词：Mg-Ni-Y Alloys;LPSO Structure;Microstructure;Mechanical Properties
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发布时间：2023-12-18 - 摘要：<正>近期公布的美铝公司2019年半年报显示,美铝预测2019年全球铝需求赤字在100～140万t之间,低于上季度预计的150～190万t;2019年全球铝需求增长在1.25%～2.25%之间,低于上季度预计。主因是受到贸易摩擦紧张局势和宏观经济带来的需求下降的影响,但即便如此,以日消费来衡量铝库存仍在下跌,预计在年底前库存将达到10日内,是2008年全球金融风暴爆发以来未有过的水平。而
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发布时间：2023-12-18 - 摘要：The power spinning process of the thin-walled tube with hard-deforming materials is a complicated forming process with interaction of many factors,such as multi-fields,multi-factors and multi-passes.So,in the spinning process,the material of the tube undergoes a complex evolution process of microstructures.And microstructures of the spun tubes can determine their service performance.Thus,to understand the microstructure evolution mechanism and control of thin-walled hard-deforming material tubes in power spinning process,it is of great significance for realizing integrated control of forming shape and performance of this type of tubes during the process.Therefore,the progress in microstructure evolution of the hard-material thin-walled tube in power spinning process was reviewed from the aspects of experiment,micro-marco scale simulation and defects analysis,and its research problems and the development trend were prospected.关键词：Hard-deforming Materials;Hot Power Backward Spinning;Microstructure Evolution;Thin-walled Tube
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发布时间：2023-12-18 - 摘要：According to the structural characteristics of the bracket,the die casting mould and die-casting process were designed.The filling and solidification process of the bracket were simulated and analyzed based on the Magma software.Then the simulated results were optimized by orthogonal experiment.The results reveal that the qualified bracket can be produced by using the optimized die casting process,which verifies the feasibility of the simulation results.关键词：Magma Software;Die Casting;Numerical Simulation
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发布时间：2023-12-18 - 摘要：The physical model of copper cooling water jacket with embedded pipe was established,and the orthogonal experiment scheme was designed.The casting process of cooling water jacket was simulated by the AnyCasting software.A satisfied experimental scheme was presented.Under the conditions of ensuring that the embedded copper pipe not melted through,the outer wall of the copper pipe and the cast copper body were well fused,which improved the thermal conductivity of the copper water jacket.关键词：Embedded Pipe;Copper Cooling Water Jacket;Simulation;Casting Process
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发布时间：2023-12-18 - 摘要：The IN738 superalloy laser welding and TIG welding were analyzed by 3D finite element analysis method,and the effects of different welding procedure on the residual stress and plastic strain were analyzed.To verify the accuracy of the simulated results,the temperature field and residual stress field were measured during welding test.The results indicate that the maximum residual stress of laser welding is higher than that of TIG welding.In the weld centerline and heat affected zone,the longitudinal residual stress of laser welding is the higher than that of TIG welding,and the tensile stress region of laser welding is the narrower than that of TIG welding.Compared to TIG welding,the plastic deformation zone width of laser welding is the smaller,and the plastic strain value is relatively lower.The calculated temperature field and residual stress field of laser welding and TIG welding are basically consistent with the measured ones,and only at the weld,there is some difference in lateral residual stress.关键词：IN738 Superalloy;Laser Welding;TIG Welding;Residual Stress;Finite Element Analysis
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发布时间：2023-12-18 - 摘要：ZL205A alloy samples were prepared by alternating magnetic field assisted with vacuum counter-pressure casting technique.The effects of solidification pressure,alternating magnetic field and alternating magnetic field-vacuum counter-pressure on the solidification feeding behavior of ZL205A alloy were analyzed by characterizing relative density of the samples.The results reveal that under the same alternating magnetic field,the relative density of the samples is increased with the increase of solidification pressure.At the same solidification pressure,the relative density of the sample is increased firstly and then decreased with the increase of the alternating magnetic field.The alternating magnetic field-vacuum counter-pressure synergistic field can agitate,oscillate and squeeze the molten metal to change the solidification feeding behavior,and refine the grain structure as well as improving the relative density of the castings.With the excitation current intensity of 10A and the solidification pressure of 350 kPa,the synergistic effect presents desirable.关键词：Alternating Magnetic Field;Vacuum Counter-Pressure Casting;ZL205A Alloy;Relative Density;Solidi-fication Pressure;Exciting Current
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发布时间：2023-12-18 - 摘要：The product structure and the main difficulties of die casting production of small bracket in automobile engine were described.The multi-cavity mold is generally used in die-casting production of small bracket.The filling of multi-cavity mould was simulated by ProCAST,and the design scheme of feeding system was adjusted according to the simulated results.The multi-cavity flow equilibrium was realized.The results show that the numerical simulation and analysis software can play an important role in the design of with multi-cavity mould and reducing development period of mould.关键词：Multi-cavity Die-casting Mould;Feeding System;Numerical Simulation;ProCAST
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发布时间：2023-12-18 - 摘要：The broken bar problem of the cast aluminum rotor was solved by replacing side gate with minimum pressure loss multi-point gate.The laminated torsion of the rotor core had been completed perfectly by using the core shaft torsional skew key.By selecting full vertical die casting machine and adopting one die four cavity rotor casting die,the placement speed,smoothness and production efficiency of the iron core inserts were improved.The rotor casting die had the advantages of simple and practical structure,reliable work,low manufacturing cost,convenient operation and low scrap rate of castings.关键词：Rotor Die-Casting;Point Gate;Torsional Skew;Broken Bar;Vertical Die-casting Machine
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发布时间：2023-12-18 - 摘要：The application of numerical simulation technology in the die casting magnesium alloy pedal was introducted.First,the gating system scheme and the technological parameters were determined by analysis,and a numerical model of the pedal was established based on the ProCAST software.Then the numerical simulation of the die casting process was carried out by the ProCAST software.The results were predicted including fluidity,gas hole and shrinkage and so on.Finally,some measures were presented to optimize the gating system and parameters.The results show that the optimized scheme is feasible.关键词：Magnesium Alloy;Die Casting;ProCAST;Numerical Simulation;Pedal
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发布时间：2023-12-18 - 摘要：The AZ91D magnesium alloy semi-solid slurry was prepared by pendulum ultrasonic vibration（LAOUV）.A sample was selected and a series of continuous metallographic images were obtained by continuous slicing technique using Mimics software.The spatial structure,spatial arrangement and size of the primary phase in the AZ91D magnesium alloy were observed and analyzed.Compared with that of two-dimensional,three-dimensional quantitative characterization can more comprehensively and truly present the data information of the internal structure of the material,and through three-dimensional structural analysis,it is concluded that with pouring temperature at 620℃,the shimmy of the rotating tube and the ultrasonic wave are beneficial for primary phase spheroidal transformation.关键词：Magnesium Alloy;Semi-solid;Three-Dimensional Reconstruction;Ultrasonic Vibration
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发布时间：2023-12-18 - 摘要：<正>2018年8月26日,三祥新材股份有限公司、宁德时代新能源科技股份有限公司、东莞宜安科技股份有限公司和江苏万顺机电集团有限公司联合开发镁合金项目签约仪式举行。四方将发挥各自优势和特长,按照协议约定合作投资设立合资公司,累计投资20亿元人民币,合作开发镁系合金材料项目。镁合金是工业金属结构材料中最轻的材料,具有良好的散热性、抗电磁干扰性以及优异的铸造性能和加工性能,回收再生利
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发布时间：2023-12-18 - 摘要：<正>近日,惠州光弘科技股份有限公司第三工业园奠基典礼,在惠州大亚湾西区新兴产业园举行。据介绍,项目总投资达19.83亿元,建设2栋生产厂房,其中2号厂房占地1万5千m2,达产后,将形成年产5G智能手机4 200万台的产能规模,整机年产量将超过1亿台,预计2020年8月落成并逐步投入使用。光弘科技业务主要涉及智能通讯终端、网络终端、多媒体终端、汽车电子、物联网等领域。
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发布时间：2023-12-18 - 摘要：<正>帕盛博（苏州）软件科技有限公司、三维流动贸易（上海）有限公司联合举办的2019 FLOW-3D CAST中国用户大会将于9月26～27日在苏州中茵皇冠假日酒店举行。据悉,本届大会将由2019 FLOW-3D CAST用户大会、（有色金属、黑色金属）研讨会两部分组成,届时将邀请FLOW-3D CAST用户、专业媒体、行业组织、OEM代表等嘉宾出席。FLOW-3D CAST中国用户大会是FLOW-3D公司和FLOW-3D CAST用户一年一度相聚和分享交流信息的重要平台。本
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发布时间：2023-12-18 - 摘要：<正>美国西部镁公司是一家低成本生产绿色初级金属镁的公司。与过时且成本高的生产工艺不同,西部镁使用连续的硅热工艺生产镁,这显著降低了相对于当前方法和工艺的劳动力和能源成本,同时对环境无害。公司近期宣布降低绿色镁金属成本的专利技术有了新的进步。在过去的十年中,西部镁一直在研究和开发一种新的生产工艺来克服批量生产方法固有的传统障碍。改良后的硅热工艺是一种连续生产工艺,具有以下优点:
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发布时间：2023-12-18 - 摘要：<正>2019年8月24日上午,春兴智能制造产业园在安徽六安市金寨现代产业园区隆重举行。据悉,开工项目由苏州春兴精工股份有限公司（下称"春兴精工"）投资建设。2017年12月,苏州春兴精工股份有限公司与金寨县人民政府签订投资协议,在金寨现代产业园区投资建设通讯滤波器压铸装配调试项目。2018年1月,春兴精工全资子公司金寨春兴精工有限公司成立,主要生产面向5G通
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发布时间：2023-12-18 - 摘要：<正>8月20日,在北京举办的2019世界机器人大会上,工业和信息化部部长苗圩表示,2018年中国的工业机器人产量超过全球产量的38%,关键核心技术需要进一步提升。中国电子学会发布的报告指出,2019年全球机器人市场规模预计将达到294.1亿美元,其中工业机器人159.2亿美元。中国机器人市场规模预计达86.8亿美元,其中工业机器人57.3亿美元。
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发布时间：2023-12-18 - 摘要：The process of furan resin sand is directly related to the performance of 3D printed complex sand.On the basis of single factor testing,the level range of four factors,such as resin addition,curing agent addition,curing temperature and curing time,was determined.The tensile strength of furan resin sand was selected as the response value and the process of furan resin sand by response surface analysis（RSA）was optimized.The prediction results show that the optimized processes for furan resin sand are presented as follows:3.6% resin addition,27% curing agent addition,curing temperature of 120℃ and curing time of 61 min.The results show that the tensile strength of the furan resin sand under the optimized process reaches 1.59 MPa,which is near to the predicted value.关键词：3D Printing;Furan Resin Sand;Response Surface Method
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发布时间：2023-12-18 - 摘要：In situ interface reaction between DZ22B superalloy and SiO2 ceramic was performed by vacuum induction melting and inertial gas protection.Both the phase structure and formation process of interfacial reaction product were analyzed comparatively at different parameters in terms of melting temperature and holding time.Moreover,the effects of interfacial reaction on sand sticking defect on the surface of castings were analyzed.The results show that Hf element in superalloy is prone to react with SiO2,resulting in the formation of HfO2.With the melting temperature of 1 400℃,there presents the tendency successively of interfacial reaction free,weak interfacial reaction and strong interfacial reaction between alloy and ceramic with extending contact time.After holding for 20 minutes,a continuous dense reaction layer with an average thickness of 0.5μm can be observed.In addition,serious interfacial reaction occurs with the increase of melting temperature.The thickness of reaction layer reaches 2.3μm at 1 600℃ for 15 min,leading to serious sand sticking defect on the surface of castings.关键词：Interfacial Reaction;Precision Casting;Superalloy;Silica Ceramic;Sand Sticking
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发布时间：2023-12-18 - 摘要：Sterling silver and anti-tarnishing silver alloys with 92.5% silver content were prepared as the base for enamelling experiments,and the enamel discoloring problems were analyzed with chromometer,microscope and X-ray diffractometer.The results reveal that the base material,glaze material properties and firing process are the main factors causing the enamel discoloration.Sterling silver can be oxidized severely at high temperature and the enamel on it is prone to discolor,while anti-tarnishing silver alloy can form protective film and improve the discoloration problem effectively,thus it should be chosen preferentially as the enamelling base material.During the enamelling jewelry production,enamel color plates should be made in advance according to the base material and glaze material,and the firing process such as glaze filling method,firing temperature,firing time and firing atmosphere should be determined reasonably according to the glaze material properties and the product structures.关键词：925 Silver;Jewelry;Enamel;Glaze Layer Discoloration
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发布时间：2023-12-18 - 摘要：According to the design characteristics of the circulating water channel in the inner cavity of the watercooled motor housing,two sand core mold solutions were compared,and the lost foam core composite casting technology was presented.The lost foam core composite casting can realize a batch of production.关键词：Motor Housing;Lost Foam Casting;Composite Casting Process
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发布时间：2023-12-18 - 摘要：The design scheme of piers,connecting bolts and tooling for straight pipe section is briefly described.Through theoretical calculation and calculation before production,the specification and quantity of connecting bolts were presented.The stress of pier base was analyzed by ANSYS finite element software to estimate the absence of failure of whole set of piers.The qualified piers and tooling were produced by vacuum EPC process.The pier base stress type test and pier base were simulated by hydraulic press.Simulatition of on-site installation reveals that absence of deformation and cracking can be observed.In addition,the field pull-out force test and analysis data of connecting bolts meet the design requirements.Through theoretical and practical verification,pier product quality meets customer requirements.关键词：Lost Foam Casting;Ductile Iron;Pier;Tooling
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发布时间：2023-12-18 - 摘要：Spark Plasma Sintering（SPS）technology was used to prepare the continuous SiC fiber reinforced TC17 titanium matrix composites（SiCf/TC17）sheet at different hot pressing time.The effects of hot pressing time on the densification rate of SiCf/TC17 were analyzed.The results show that the relative density of SiCf/TC17 is improved with the increase of the hot pressing time,and the densification rate can be basically realized at 900℃and 50 MPa for 15 min,with the relative density of 99.41%.In addition,by combining the SPS parameter curves with representative microstructure characteristics,the densification process of SiCf/TC17 can be divided into three stages:the purification and activation of precursor fiber surface,the rapid densification and the creep densification.On this basis,the deformation and densification mechanism of titanium alloy coating of SiCf/TC17 precursor fibers in SPS process were described.关键词：Titanium Matrix Composites;Spark Plasma Sintering;Densification Mechanism
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发布时间：2023-12-18 - 摘要：(TiB+TiC)reinforced Ti-6Al-4V matrix composites were in-situ synthesized through low energy milling and spark plasma sintering.The effects of sintering temperature and B4C addition on the microstructure and properties of the composites were investigated.The results show that sintered at 1 000～1 150 ℃,the reinforcments are distributed at the boundary of the original particles at 1 100℃,which is discontinuous in form of a network,and the yield strength,compressive strength and engineering strain of the composites reach the maximum value.Microstructure of matrix alloy presents lamellar Wei’s structure,which is flakyαandβin composites,and the grains of composites are refined remarkably.As the increase of the reinforcements content,microhardness is increased,while the engineering strain is decreased.The strength of the composites reaches the highest at 2% B4C addition,where yield strength and tensile strength reach 1 410.55 MPa and 1 771.65 MPa,respectively.
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发布时间：2023-12-18 - 摘要：To solve the problem of graphene aggregation in Mg-based alloys,the method of electrostatic attraction was adopted to mix graphene oxide prepared by Hummers method with ZK61 alloy powder which was picklled,and ZK61 Mg-based composites were prepared by powder thixoforming technology.The effects of preparation parameters on the dispersion effects of graphene oxide in matrix and the mechanical properties of the composites prepared were analyzed.The results reveal that after 0.1% graphene oxide is treated by ultrasonic at 840 Wfor 40 min and then mixed with magnesium alloy powder after acid pickling at 1%concentration,graphene oxide is dispersed uniformly in the matrix after thixoforming.The ultimate tensile strength and elongation of the composites are increased by 42.97% and by 6.76%,respectively,compared with those of the matrix alloy,while the change of hardness can be ignored.关键词：Magnesium Matrix Composite;Electrostatic Attraction;Graphene Oxide;Dispersity
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发布时间：2023-12-18 - 摘要：A failure of piston pneumatic actuator was observed,which was caused by the fracture of the piston plate.In order to understand the cause for the fracture of piston plate in this batch,the failure analysis of coupling in each case was performed by microstructure observation,chemical composition analysis,scanning electron microscopic analysis.The results show that the fracture of piston plate in this batch belongs to fatigue fracture,which are caused by serious stress concentration existed at the bottom of sealing groove.Meanwhile,a higher strength aluminum alloy 7A19 was used which accelerated the fatigue cracking.Through selecting 5083 alloy,service life of piston plate was improved greatly with technological modification.关键词：Piston Plate;Fatigue Fracture;Failure Analysis
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发布时间：2023-12-18 - 摘要：The Al-Si alloy with high thermal conductivity was prepared by the metal mold casting,and the effects of heat treatment parameters（solution temperature）on the thermal conductivity and mechanical properties of the alloy were investigated by a single test method through optical microscopy（OM）and scanning electron microscopy（SEM）,laser thermal conductivity analyzer,tensile test and other characterization methods to analyze comparatively the microstructure,tensile strength,elongation and thermal conductivity of the alloy before and after heat treatment.The results reveal that thermal conductivity of the alloy reach 153.1 W/（m·K）,the shape of the primaryα-Al phase becomes regular with the increase of the solution temperature after solution treatment,and the eutectic silicon begins to break and spheroidize from irregular lamellar.The thermal conductivity of the alloy is increases first and then decreased.At 540℃,the maximum value is 190.8 W/（m·K）,which is increased by 24.6%,while it is decreased sharply at 560℃.The tensile strength is increased from 188.35 MPa at the as-cast state to 255.74 MPa at 540℃,and the elongation is increased from 4.5% to 14.41%.关键词：Al-Si Alloy;Solution Temperature;Microstructures;Thermal Conductivity;Mechanical Properties
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发布时间：2023-12-18 - 摘要：The effects of Sr on microstructure and biological corrosion behavior of as-cast Mg-1.38Si alloy were investigated.The results show that Sr presents preferable modification effect on Mg2Si phase in Mg-1.38Si alloy.With the increase of Sr,the morphology of eutectic Mg2Si phase is changed from thick Chinese character to fine short rod-like,and the morphology of primary Mg2Si phase is changed from polyhedral to particle-like.The hydrogen evolution rate,the corrosion rate and the corrosion current density of the alloys are increased gradually with increasing in Sr addition,indicating that the corrosion resistance of the alloys is gradually decreased in SBF solution.关键词：Sr;Mg-Si Alloy;Microstructure;Biocorrosion Behavior
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发布时间：2023-12-18 - 摘要：Effects of final rolling temperature on microstructure and mechanical properties of large strained Al-CuMg-Sc alloy were investigated by means of microstructure analysis,tensile test and XRD analysis.The results reveal that there are mainly Sphase,θphase and a small amount of Al3Sc phase in Al-Cu-Mg-Sc alloy.When final rolling at different temperatures,the microstructure presents banded structure and fine second phase particles are distributed along rolling direction.After the final aging treatment,a large amount of fine and dispersed second phase is precipitated in the alloy.When the finishing temperature is below 200℃,the yield strength change of the alloy can be ignored.After final rolling at 200℃+150℃×4 h,Al-Cu-Mg-Sc alloy has the desirable comprehensive mechanical properties,where the tensile strength and elongation reach 622.85 MPa and 13.33%,respectively.关键词：Al-Cu-Mg-Sc Alloy;Final Rolling Temperature;Microstructure;Mechanical Properties
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发布时间：2023-12-18 - 摘要：The effects of ultrasonic treatment,Sr-Y alloying treatment and ultrasonic-alloying compound treatment on the solidification structure and mechanical properties of Mg-9Al-3Si alloy were investigated.The effects of different ultrasonic parameters on the solidification structure and mechanical properties of the alloy were analyzed.The results reveal that the solidification structure and mechanical properties of the alloy are obviously improved under the condition of ultrasonic-alloying treatment,which is superior to those of the single alloying treatment or ultrasonic treatment.Compared with untreated ones,the size of treated primary Mg2Si phase is reduced by 72.9%.Meanwhile,tensile strength and elongation of the alloy are increased by 125% and by 310%,respectively,compared with those of untreated alloy.With the increase of ultrasonic power or ultrasonic time,the size of primary Mg2Si phase is decreased gradually,and the change of mechanical properties corresponds to the size and morphology of primary Mg2Si phase.关键词：Mg-9Al-3Si Alloy;Ultrasonic Treatment;Alloying Treatment;Solidified Structure;Mechanical Properties
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发布时间：2023-12-18 - 摘要：The interfacial reaction of Cu/Sn/Cu micro-solder joints aged for 0 h（post-weld state）and 400 hat 110℃ was investigated by means of electron backscatter diffraction（EBSD）.The results show that the microstructure of Cu/Sn/Cu micro-solder joint after interfacial reaction is composed of Cu6Sn5,Cu3Sn and beta-Sn.After400 hisothermal aging,a large amount of beta-Sn is consumed.The morphology of Cu6Sn5 is changed from scallop-like to polygon-like,and Cu3Sn still keep long strip-like structure.For orientation,the preferred orientation of Cu6Sn5（0001）surface is present after 400 hisothermal aging and <0001> crystal direction is parallel to RD direction.The interfacial type of Cu6Sn5 after 400 haging was analyzed.The orientation difference angle is about 53°,45°,36°,presenting large angle grain boundaries.The analysis of microstructure and grain orientation shows that isothermal aging has a little effect on the orientation of microstructures morphology of solder joints,however it will affect greatly the transformation and growth of microstructures.关键词：Cu/Sn/Cu Micro-solder Joint;EBSD;Interface Reaction;Microstructure;Grain Orientation
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发布时间：2023-12-18 - 摘要：The high chromium Cu-Cr-Zr alloy was prepared by vacuum melting process,and the high chromium Cu-Cr-Zr spring contact wire was prepared by extrusion,rolling,multi-pass drawing and intermediate annealing.The performance of the spring contact wire was measured.The results show that the electric conductivity and the tensile strength reach 43.419～47.345 MS/m and 650～742 MPa,respectively.The comprehensive performance is much higher than that of the traditional beryllium copper,samarium cobalt copper and chrome zirconium copper spring contact wire.In order to improve the quality of high chromium Cu-Cr-Zr alloy ingots,the alloy smelting process was analyzed in detail,especially to strengthening manual feeding.关键词：High Chromium Cu-Cr-Zr;Vacuum Melting Process;High Strength;High Conductivity;Spring Contact
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发布时间：2023-12-18 - 摘要：In order to understand the effects of copper-tin ratio on the friction and wear properties of copper-based friction materials,the copper-based friction materials with w（Sn）/w（Cu+Sn）of 0,6%,9% and 12%（in weight）were prepared by powder metallurgy process.The microstructure and micro-hardness as well as friction and wear properties under different applied loads were analyzed.The results show that the micro-hardness of copper matrix and the wear resistance of the materials are improved obviously by adding metallic tin in copper-based friction materials.When w（Sn）/w（Cu+Sn）is 9%,the main wear mechanism is abrasive wear,demonstrating better wear resistance at high applied load.关键词：Powder Metallurgy;Copper-based Friction Material;w（Sn）/w（Cu+Sn）;Abrasive Resistance
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发布时间：2023-12-18
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