最新刊期
卷 37 ， 期 4 ， 2017
- 摘要：The dendritic growth of an Al-3Cu-1Mg alloy was calculated using a three-dimensional cellular automaton model.Effects of the off-diagonal terms of the solute diffusion coefficient matrix on the dendritic growth during solidification of the alloy were investigated.The solute diffusion coefficients were treated in two ways:（1）by considering the concentration-dependent and temperature-dependent diffusion,and neglecting the effect of solute interactions or the off-diagonal terms of the diffusion matrix,or（2）by calculating the diffusion coefficients by solving the full diffusion matrix.The results indicate that the calculated dendrite tip selection parameter is the smaller than that obtained using the marginal stability criterion.When the off-diagonal terms of the solute diffusion coefficient matrix are considered,the growth velocity of the dendrite tip is decreased,while the dendrite tip radius is increased as a result of the attraction of the solutes in the Al-Cu-Mg system.关键词：Dendrites;Diffusion;Numerical Simulation
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发布时间：2023-12-18 - 摘要：Based on metallograph of tomographic slices,the 3Dreconstruction method was applied for analyzing the microstructure characteristics of semi-solid 7075 Al alloy by the digital processing technique.The samples of semi-solid 7075 Al alloy were prepared by the recrystallization and partial remelting process,and then the two-dimensional photos of tomographic slices were obtained by metallographic microscope.After the digital processing process including locating,aligning,thresholding and stacking of multilayer images,the 3Dmicrostructure was reconstructed by converting the two-dimensional information to three-dimensional information.From the reconstructed 3D microstructure,it is found that the microstructure of semi-solid 7075 Al alloy prepared is connected or isolated liquid phase filled in the gaps among the solid phase.The space structure feature of microstructure of semi-solid alloys can be characterized easily by 3D microstructure,so the microstructure can be characterized more accurately.关键词：Three-Dimensional Reconstruction;Microstructure;7075Al Alloy;Semi-solid Alloy
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发布时间：2023-12-18 - 摘要：<正>由重庆铸造行业协会、重庆市机械工程学会铸造分会主办的"2017重庆铸造协会年会"将以"创新驱动、共谋发展"为主题于5月2325日在渝召开,会议的举办方将组织重庆以及外地铸造企业和与铸造有关的企业在本届展会
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发布时间：2023-12-18 - 摘要：<正>经过多年潜心研发,富乐压铸（太仓）有限公司实现了锌合金压铸件表面处理技术的新突破--纳米涂层技术。作为一项绿色环保、高性能的新技术,富乐纳米涂层技术应用于锌压铸件,可以极大地防止破损和腐蚀,并且涂覆十分方便,不需要改变铸件的任何结构。
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发布时间：2023-12-18 - 摘要：<正>工信部部长苗圩在"中国发展高层论坛"2017年年会上表示,我国制造业重大创新成果不断涌现:ARJ21-700新型涡扇支线客机正式投入商业运营;C919大型客机完成大部分地面试验即将首飞;长征五号大运载火箭、载人航天、全球首颗量子卫星发射成功;中国标准动车组成功完成世界首次420km/h交汇试验。
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发布时间：2023-12-18 - 摘要：<正>2017年3月910日,"2017（第四届）中国汽车轻量化技术与铝镁轻金属应用合作峰会"在安徽合肥召开。来自铝镁等有色金属生产、研究单位与各大汽车制造厂商共150余位代表参加会议,共商汽车轻量化解决方案,对汽车轻量化产业链进行了广泛交流,推进深入合作。本次会议的主题是""汽车轻量化技术交流-铝镁应用合作"。
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发布时间：2023-12-18 - 摘要：<正>我国是世界上镁资源最为丰富的国家之一,也是全球原镁的最主要供应国。与其他合金相比,镁合金性能优良,在金属结构材料中质量最轻,密度为铝的2/3,不到钢的1/4,集高减振性、高热传导性、高刚性、高抗弯曲性于一身,可延长压铸件的使用寿命。
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发布时间：2023-12-18 - 摘要：<正>从山西省科技厅获悉,由中北大学科研团队完成的国家攻关项目"镁及镁合金综合环保型技术开发及产业化"中的"大型复杂镁合金承力构件阶梯温度径向轴向控制流动精确成形技术",经过山西十多家企业的实际应用,效果明显,部分产品已出口。近3年累计新增产值13.6亿元,新增利税1.7亿元,出口创汇6 600万美元。
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发布时间：2023-12-18 - 摘要：<正>陕西眉县吹风机厂与宝鸡华泰金属技术公司通过科技资源整合,共同研制了钛制式离心机,这项技术是我国在该领域的首次尝试,打破了国外对我国的垄断。离心机是军工、化工、冶炼等工业生产中常用的设备之一。眉县吹风机厂针对市场上对离心机的设备要求,结合宝鸡钛产业占有全国80%的钛材资源,着手研发利用钛材生产离心机设备。由眉县吹风机厂提供风机的加工技术,并对技术进行改进;华泰公司负责对材料的特性进行研究,以探索出钛材适用于风机加工的可行条件。在双方的联合
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发布时间：2023-12-18 - 摘要：<正>由香港城市大学领头的研究团队发现金属玻璃成型过程中一种不为人知的无定型状态,破解了40年来科学界的一个谜团。城市大学近日公布,这项发现有助于研制更优质的新型金属合金。研究指出,有关研究由城市大学物理及材料科学系系主任兼讲座教授王循理领导。他说,研究结果解开了40年来科学界的一个谜团;他们希望通过改变金属玻璃的纳米结构,从而研制更多的新型材料。
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发布时间：2023-12-18 - 摘要：Based on the 2024 aluminum alloy extrusion rod isothermal heat treatment,formation mechanism and influence factors of semi-solid microstructure were investigated.The processing parameters for the industrial application were presented by analyzing the gear parts manufactured by the technology.The results reveal that desirable microstructure can be observed at 626 ℃ for 10 min,and the tensile strength reaches 290 MPa.关键词：2024 Aluminum Alloy;Isothermal Treatment;Semi-solid State;Thixo-forging
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发布时间：2023-12-18 - 摘要：In order to improve microstructure and composition segregation of the casting titanium alloys,TC4 alloys was fabricated by powder metallurgy method based on mixing element method and cold isostatic pressing.The effects of sintering temperature on performance and microstructure of TC4 alloys were investigated by OM,SEM and tensile testing.Results show that the microstructure of sintered TC4 alloys can be refined obviously and it is mainly composed ofαandβphase with the uniform distribution of element.With increasing in sintering temperature,tensile1 strength of the sintered TC4 alloy can be improved greatly.With sintered temperature more than 1 260℃,increase of mechanical properties of the alloy can be ignored with increasing in sintering temperature.Elongation of the alloy is increased firstly and then declined with sintering temperature increase.The maximum value of tensile strength and elongation can reach up to 1 018 MPa and 8.8%,respectively.关键词：Sintering Temperature;TC4 Alloys;Microstructure;Performance
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发布时间：2023-12-18 - 摘要：The microstructure of Al-0.01Zr-0.02 Balloy conductor wire with trace Er element was observed and analyzed by optical microscopy,scanning electron microscopy,transmission electron microscopy,and the mechanical and electrical properties were measured to understand effects of Er element on Al-0.01Zr-0.02 Balloy.The results show that with the addition of trace Er element,the second phase particles Al3 Er,Al3（ZrEr）are generated and microstructure of the Al-0.01Zr-0.02 Balloy is improved,so the comprehensive performance is improved.关键词：Er Element;Aluminum Alloy;Conductor Wire;Microstructure and Properties
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发布时间：2023-12-18 -
Effects of β-Mg17Al12 Morphology on Microstructure and Mechanical Properties of As-rolled AZ80 Alloy
摘要：β-Mg17Al12 phases with various distribution features in AZ80 alloy were observed by homogenizing treatment at 420 ℃ for different time.The effects ofβphase on microstructure and mechanical properties of as-rolled AZ80 alloy were investigated by metallography microscopy,scanning electron microscopy（SEM）and tensile tests.The results show that the size,morphology and distribution ofβphase are closely related with the dynamic recrystallization behavior during hot rolling process.Coarseβphase distributed along the grain boundaries can promote dynamic recrystallization and enhance the formation of fine grain band.However,when most ofβphases are tiny and distributed just in grain interiors dispersedly,fine grain bands become uncompleted and twinning happens in some initial grain interiors.The desirable comprehensive mechanical properties of as-rolled AZ80 alloy can be presented by homogenizing at 420 ℃for 12 h.关键词：β-Mg17Al12 Phase;AZ80 Magnesium Alloy;Rolling;Dynamic Recrystallization- 2
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发布时间：2023-12-18 - 摘要：The effects of different aging time on microstructure and properties of hot-extruded GH3625 alloy tube at 720℃ were investigated by means of scanning electron microscopy（SEM）,energy-dispersive spectrometry（EDS）and Image-Pro plus metallographic analysis software.The results indicate that the M23C6,γ" phase andδphase are mainly precipitated in the GH3625 alloy at 720℃ during long term aging,and the strength and hardness of GH3625 alloy are increased,however,the plasticity is decreased drastically.With the increase of aging time,some M23C6 phases are transformed into M6C,and most of theγ"phases are transformed into acicularδphase.In addition,after aging for 5 000 h,theδphase is changed from long acicular to long rod-like,weakening strengthening effect ofγ" phase.Theδphase is grown up with aging time and the average growth rate length 5.9×108 nm3/h,following LSW theory,while the average width of coarsening is deviated from the LSW theory.关键词：GH3625 Superalloy;Longterm Aging;δ Phase;LSW Theory
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发布时间：2023-12-18 - 摘要：The uniformity of mold temperature distribution is the important factor affecting the quality of automotive injection products,and 60% plastics product’s defects are caused by mold cooling system as a result of un-suitable design.Due to the trolley trim cover defects,the mathematical model was established,and boundary and initial conditions were taken into account to analyze the temperature field of defects positions based on the ANSYS software.The results show that the surface temperature and center temperature reach 141.7℃and 229.1℃,respectively,so temperature difference reaches up to 87.4℃,which is not meet the requirements of plastics.The cooling system structure of the mold was re-designed.At the same injection conditions,continuous samples 3 000 products show 100% qualified rate.关键词：Mold;Temperature;Cooling System;ANSYS;Top White
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发布时间：2023-12-18 - 摘要：By using powerful spinning SXD100/S3-CNC numerical control machine,different processing parameters（thinning ratio,feeding ratio,working angle）of connecting rod bushing manufactured and the springback were measured.Based on orthogonal experiment,taking the thinning ratio and the feed ratio,the working angle as the input layer,and the springback degree as the output layer,prediction model of powerful spinning rod bushing springback was established by BP neural network,and it was trained and predicted by testing data.The results reveal that the model exhibits a higher prediction accuracy,and it can predict accurately the springback of connecting rod bushing manufactured under different powerful spinning processing parameters.关键词：Connecting Rod Bushing;Powerful Spinning;Springback Rate;BP Neural Network
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发布时间：2023-12-18 - 摘要：Some key technologies for numerical simulation in casting were analyzed,and the SIMU-CAST software was developed.The software has the function of solidification field and prediction of shrinkage porosities during casting process based on FEM method,in which non-leaner features of materials and boundary conditions as well as latent heat were taken into account.The simulated results from SIMUCAST were verified by ProCAST and experiment.The results reveal that the developed software exhibits the high accuracy in calculation and simulation,meanwhile,prediction of shrinkage porosities is well agreement with the practical ones,meeting the industrial application.关键词：Casting Technology;Numerical Simulation;Software Development
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发布时间：2023-12-18 - 摘要：Elimination of die casting defects in mold design and filling process of camshaft bracket for motorbike was described.Through numerical simulation,feasibility of gating system design was analyzed.Aiming at problems in mold design,gas hole defects were decreased greatly through shortening pre-casting mold core.关键词：Camshaft Bracket;HPDC;Casting Defects
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发布时间：2023-12-18 - 摘要：Solidification process of low pressure casting aluminum alloy wheel at different holding pressure was visualized by a software to analyze feasibility of low pressure casting aluminum alloy wheel at the higher holding pressure.The results reveal that with increasing in holding pressure,solidification rate of the alloy is increased,and microstructure of the aluminum alloy wheel is more compact,so yield strength and elongation of the wheel are increased by 15% and 70%,respectively.Meanwhile,impact resistance of the aluminum alloy wheel is improved.关键词：Low Pressure Die Casting;Holding Pressure;Aluminum Alloy Wheel;Lightweight Design
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发布时间：2023-12-18 - 摘要：Filling process of die casting aluminum alloy carburetor midbody was simulated by the ProCAST software.By analyzing temperature field and flow field in die-casting process of aluminum carburetor and observing distribution and volume of predicated flaws,the optimized parameters of die-casting process were presented as follows:the injection speed of 2.5m/s,mold preheating temperature of 210℃,pouring temperature of 620℃and ingate thickness of 2.5mm.Through adopting the optimized parameters,the qualified carburetor midbody was produced successfully.Microstructural observation reveal,that the simulated defects are well in agreement with the practical ones.关键词：Aluminum Alloy;Carburetor Midbody;Numerical Simulation;Process Optimization
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发布时间：2023-12-18 - 摘要：The rotating-rod induced nucleation（RRIN）was adopted to fabricate the semi-solid slurry of A356 alloy,and influence of holding time on the microstructure of A356 aluminum alloy semi-solid slurry was investigated.The results show that,with the increase of holding time,the primary phase size is increased gradually,however,the shape factor of the primaryα-Al is decreased firstly and then increased,which follows the Oswald ripening mechanism.With holding for 1min,the equivalent diameter of the primary phase is about 54μm with shape factor of 0.89,while the number of particles per unit area is about 175/mm2.With the holding time of 5min,the primaryα-Al shape factor is 0.83,and its equivalent diameter reaches about 74μm,and number of particles per unit area is about 130/mm2.However,the shape factor reaches the largest with the holding time of 20 min,as much as 0.97,and the number of particles per unit area is about 70/mm2.关键词：Holding Time;A356 Alloy;Rotating-rod Induced Nucleation（RRIN）;Semi-solid Billet
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发布时间：2023-12-18 - 摘要：The analysis methods and program of investment casting defects were described briefly.Defects difficult to identification can use microstructure analysis,chemical analysis,acidic immersion,OM and XRD.Hot crack in investment castings was analyzed.Through increasing pouring temperature and shell-mold deformability to decrease stress,and modifying casting structure to realize sequential solidification,hot crack is eliminated and waste rate is decreased.关键词：Investment Casting;Defects Analysis;Hot Crack
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发布时间：2023-12-18 - 摘要：The method of accelerating shell mold drying rate was analyzed in the process of making shell with complex cavity body.In the process of silica sol shell making,casting defects often occur in the inner cavity of the valve body as a result of poor drying.Shell mold drying speed is too slow in the whole shell making process,seriously affecting the shell making cycle.Through designing the device for accelerating the drying speed of shell mould,the casting defects caused by poor shell mold drying are decreased greatly.Meanwhile,the shell-making period is shortened obviously.关键词：Drying Rate;Casting Defects;Shell-making Cycle
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发布时间：2023-12-18 - 摘要：<正>德州大学奥斯汀分校机械工程和材料科学教授John Goodenough领导的团队发明了一种快速充电的低成本全固态电池。研究人员称,新型电池提升了能量密度,并延长电池寿命。
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发布时间：2023-12-18 - 摘要：<正>俄罗斯铝业联合公司预计2017年全球铝市场供应不足将扩大至110万t;预计铝市场在2017年将录得良好表现。在中国国内,限产对铝价刺激作用也有一定效果,沪铝期价今年以来涨幅8.98%,价格一度创下2015年以来最高点,而且接近2014年最高点。
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发布时间：2023-12-18 - 摘要：<正>近日,美国麻省理工学院MIT的物理学家发现一种新的物质形态:超固体。这种物质形态同时具备了固体和超流体的性质。研究人员用激光操纵处于玻色-爱因斯坦凝聚的气态超流体,使它们同时进入于一种全新的量子态中--超固态。这种量子态具有晶格结构,同时还拥有超流体本身的无粘性流动特性。理解这种明显矛盾的物质状态可以帮助我们更好地理解超流和超导的性质,从而极大促进超导磁体,超导传感器以及能量传输等行业的发展。该项研究发表在《Nature》杂志上。该项目领头人Wolfgang Ketterle说:"超固体既能流动又有固体的结构,这的确很反常识。当你搅拌一杯具有超流性的咖啡时,咖啡会永远旋转下去。"物理学家们曾经预测会有超固体的存在,但迄今为止仍未在实验室发现。有人从理论上提出,如果可以在低温条件下,让处于超流体状态下的氦原子绕着氦晶体运动,从而形成等效意义上的超固体。Ketterle团队采用钠原子实现了超固体。由
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发布时间：2023-12-18 - 摘要：A stepwise vacuum diffusion bonding method was used to fabricate Cu/Al joint with varied thickness of Ni intermediate layer.The interfacial microstructure and metallurgical reaction between Cu and Al were investigated.The morphology and phase composition of heterogeneous composite interface were analyzed by scanning electron microscopy（SEM）and energy disperse spectroscopy（EDS）.The shearing strength and the micro-hardness of the joint were measured by shearing experiment and hardness testing.The results reveal that,Ni intermediate layer can prevent effectively generation of brittle intermetallic compound phase in the Cu and Al.Compound phase of two layer Al3Ni and Al3Ni2 can be observed in Ni/Al interface,and there exists solid solution phase with clear elemental composition gradient in the Cu/Ni interface.When Ni foil thickness is 20μm,Ni foil just be completely consumed,so obvious defects are absent in interface,and the interface shear strength reaches maximum value.关键词：Ni Intermediate Layer;Diffusion Bonding;Microstructure;Interface Reaction
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发布时间：2023-12-18 - 摘要：A new type casting SiCp-GRp/Zn-35Al-1.2Mg composites were prepared with adding different content of graphite GRp,SiCp,SiCp/Al、GRp/Al and SiCp+GRp/Al by powder pressed sintering method combined with stirring casting process.Micro-vickers hardness and as-cast microstructure of the novel aluminum-zinc composites were measured at different loading and time.The results reveal that the reinforced silicon carbide and graphite particles can be distributed uniformly in the matrix,and matrix hardness is increased by 8.5% with single adding SiCp,while the matrix hardness is decreased by 15.4% with only adding GRp,however,matrix hardness is reduced by 6.2% with adding SiCpand GRp.The temperature increment rate of the aluminum matrix zinc alloy reaches 45.7 ℃/s at 150 Nload,while the temperature increment rate of the composites with the single addition graphite particles is only 26.1 ℃/s,however,the temperature decrement rate reaches 50.4℃/s during the wear end stage.Meanwhile,the decrement rate of the composites with single addition silicon carbide particles is 33.6℃/s.At 30 Nfor 600s,anti-friction behavior of the composites with GRp exhibits desirable,and the wear loss of the matrix is reduced by 19%,while at 60 N for 600 s,the anti-friction and anti-wear effect of composites with the silicon carbide and graphite compound particles exhibits desirable,and the wear loss is reduced by 17%.In addition,the wear-resistance index of the composites with only adding SiCp is increased by 34% during wearing at 150 Nload.
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发布时间：2023-12-18 - 摘要：Submicron SiC particle reinforced Al matrix composites was fabricated by powder metallurgy method.The microstructure of the as-prepared composites was observed by scanning electronic microscopy（SEM）,and the mechanical properties were characterized by tensile testing and Brinell hardness test.The results reveal that with increasing in the volumetric fraction of SiC submicron particles,the relative density of Al-matrix composites is decreased,and hardness and frictional coefficient are increased,while tensile strength and the wear rate of the composites are increased firstly and then decreased.When the volumetric fraction of SiC submicron particles is 6.0%,tensile strength of the composites prepared reaches the maximum value with low wear rate.When SiC submicron particles were added into the aluminum matrix composites,due to its high hardness and strength bearing to certain loading to hinder the sliding of the grain boundaries,mechanical properties and wear resistance of Al matrix composites were improved.关键词：Al-matrix Composites;Powder Metallurgy;Volumetric Fraction;Nano-sized SiC
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发布时间：2023-12-18 - 摘要：The 15%cin volumetric fraction,chopped carbon fibers reinforced magnesium composites(Csf/AZ91D)were prepared by vacuum assisted pressure infiltration method,and the isothermal constant strain rate compression experiment of Csf/AZ91 Dcomposites was carried out at the deformation temperatures from 400 ℃to 460 ℃ and strain rates from 0.001s-1 to 1s-1 and the true strain of 0.7to understand the behavior of flow stress and dynamic recrystallization.The results indicate that the softening mechanism of the dynamic recrystallization is a feature of true stress-true strain curves of Csf/AZ91 D composites,and the critical strain is decreased with increasing in temperature or decreasing in strain rate.The functional relationship with parameter Zcan be exhibited asεc=1.6×10-3 Z0.037 2 and there enists a linear relationship between critical strain and peak strain,εc=0.385 2εp.The critical strain of the composites is much less than that of magnesium alloy AZ91 D,and the chopped carbon fibers promote the occurrence of dynamic recrystallization of matrix magnesium alloy and refine the recrystallization grains.关键词：Csf/AZ91D Composites;AZ91D;Work Hardening Rate;Dynamic Recrystallization;Critical Strain
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发布时间：2023-12-18 - 摘要：Hot deformation behavior of ZE42 magnesium alloy was investigated by compression tests at elevated temperatures in the range of 300450℃and 0.0110s-1,respectively.Processing map was presented based on dynamic material model（DMM）at the strain rate of 0.35,0.40 and 0.45.The results reveal that average value of hot deformation apparent activation energy of ZE42 magnesium alloy reaches 151kJ/mol at experimental temperature range.The strain rate has significant effect on the processing map of the alloy.The alloy exhibits un-stability only in two tiny vicinities of 300 ℃,10s-1 or320 ℃,0.01s-1.However,the instability areas are mainly distributed in the wide range of more than320 ℃,ε= 0.1 1.0s-1 at strain of 0.35 and 0.45.The optimum hot working domain is presented as follows:350 450 ℃,ε≤ 0.1s-1 with about 83% peak efficiency of power dissipation（ηmax）,and the main flow deformation mechanism is characterized by continuous dynamic recrystallization（DRX）cooperative with grain boundary sliding.关键词：Magnesium Alloy;Compressive Deformation;Constitutive Equation;Processing Map
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发布时间：2023-12-18 - 摘要：Porous Al-5Cu alloys were fabricated by GASAR（the metal-gas eutectic method）method.Influences of temperature and hydrogen pressure on porosity of the GASAR Al-5Cu alloys were investigated.The results reveal that increase of temperature and hydrogen pressure can improve the hydrogen solubility in the liquid Al-Cu alloy,resulting in the increase of porosity.The mechanism of pore formation in GASAR Al-5Cu alloy is described:pores formed in eutectic phase and grown with the movement of liquid/eutectic solid interface.In addition,the compressive behavior of GASAR Al-5Cu was also analyzed.关键词：GASAR;Al-5Cu Alloy;Porosity;Compression Properties
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发布时间：2023-12-18 - 摘要：The effects of MnCO3 addition on grain size of the cast Mg-Al alloys were investigated by adding the refiner into the melt,and the refinement mechanism was described by using the edge-to-edge matching model combined with thermodynamics and microstructure analysis.It can be found that MnCO3 has significant refining effect on grain size in as-cast Mg-Al alloys,especially for AZ31 alloy.Based on calculation of the edge-to-edge matching model and thermodynamics analysis of microstructure,the Al4C3andτ-AlMn phase can be generated from molten magnesium alloys modified by MnCO3,which exhibit multiple pairs of ORs with Mg as the potential nucleus of Mg grain.关键词：Mg Alloys;MnCO3;Grain Refinement;Edge to Edge Matching Model
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- 111
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- 2
发布时间：2023-12-18 - 摘要：DEFORM-3Dsoftware was used to simulate the equal channel angular pressing（ECAP）of different cross-section workpieces.The distribution of strain and damage factor during the deformation process of the EACP with circular cross-section and square cross-section were analyzed,which provided a reference for the actual experiment of canned-ECAP of AZ31 magnesium alloy.The results show that distribution of equivalent strain is similar at different sections,and the equivalent strain distribution at the vertical direction exhibits more uniform.In extrusion process,the circular cross-section specimen is completely in the compressive stress state,while the tensile stress of the square cross-section specimen in the shear deformation zone will cause the cladding to crack,and the internal blanks will initiate crack or even fracture.Compared with square cross-section specimens,damage factor of circular cross-section is very small.AZ31 magnesium alloy cladding ECAP workpiece cross-section is set to circular cross-section.关键词：Canned-ECAP;Magnesium Alloy;Finite Element Simulation;Cross-section
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- 99
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发布时间：2023-12-18 - 摘要：The degassing efficiency and its effect on the melt quality of several refining process often used in casting aluminum alloy were analyzed comparatively.The results reveal that the compound method of C2Cl6 and rotating blowing argon process exhibits the satisfied refining effects,where the degassing effects are desirable and burning-loss of magnesium element is in the controllable range,meanwhile,the alloy has the high comprehensive properties.关键词：Aluminum Alloy;Refining Process;Effect
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- 193
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发布时间：2023-12-18 - 摘要：Effects of cooling modes on microstructure and properties of the 2219 aluminum alloy ingot after homogenization were investigated using optical microscopy,scanning electron microscopy with energy dispersive,hardness and electrical conductivity testing.The results show that the semi-continuous casting ingot presents a honeycomb-shaped eutectic microstructure on the grain boundary with severe segregation.The spherical and bulk-shaped CuAl2 phases and accicular Al7Cu2（Fe,Mn）phases are distributed along grain boundary after homogenization.Absence of second phases precipitated within the grains can be observed after water quenching at 530 ℃.During the close furnace cooling process,with the quenching temperature decrease,the volume fraction and size of the second phases precipitated within the grains are increased.As a result,the hardness is decreased and the electrical conductivity is increased of the alloy after artificial aging treatment.关键词：2219 Aluminum Alloy;Homogenization;Cooling Mode;Microstructure
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- 134
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- 1
发布时间：2023-12-18 - 摘要：The effects of wall thickness on microstructure and properties of ZL101 alloy by lost foam casting under the condition of no-vibration and vibration were investigated,and the mechanism was described.The results show that,with the increase of wall thickness of the specimens,the grain size of ZL101 alloy is increased under the condition of no-vibration and vibration,however the primaryα-Al is relatively small and uniform,and the shape is more spherical in ZL101 alloy under vibration.Compared with the ZL101 alloy without vibration,the grain size and second dendritic arm spacing are decreased,and the primary phase shape coefficient is relatively larger under the condition of vibration at the same wall thickness.With the increase of the wall thickness of specimen,the tensile strength,yield strength,hardness and elongation are gradually decreased of ZL101 alloy under the condition of vibration,however compared with that without vibration,the tensile strength,yield strength,hardness and elongation of ZL101 alloy are greatly improved at the same wall thickness.关键词：Mechanical Vibration;Lost Foam Casting（LFC）;ZL101 Alloy;Microstructure;Properties
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- 894
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发布时间：2023-12-18 - 摘要：Effects of Ce or La addition on microstructure and mechanical properties of the Al-8.5Mg-0.5Mn aluminum alloy were investigated by means of optical microscopy（OM）,tensile test,scanning electron microscope（SEM）and energy spectrum analysis（EDS）.The results indicate that microstructure of the alloy can be refined via adding Ce or La,which is changed from dendritic morphology and to indistinct dendritic morphology and to equiaxed grain structure.A little Al4 Ce with fish-bone shape can be generated in the alloy with Ce addition,while absence of coarse Al-La phase can′t be observed in phase and grain boundary of the alloy with La addition.The mechanical properties of high-magnesium aluminum alloy can be improved to some certain with the addition of Ce or La,however their trend is almost the same.There are two peak values as follows:the first tensile strength peak value of 180190MPa with Ce or La addition of about 0.25%;the second peak value of 220230MPa with Ce or La addition of 1.5%.The elongation of alloy with La is the higher than that of ones with Ce.关键词：Al-8.5Mg-0.5Mn Alloy;Rare Earth Element;As-cast Microstructure;Mechanical Properties
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- 144
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- 2
发布时间：2023-12-18 - 摘要：Using copper-mould spray casting techniques combined with vacuum induction melting,non equilibrium solidified samples of AZ91 magnesium alloy containing nano SiC particles were prepared at the large cooling rate.After solid solution treatment at 400 ℃for different time,effects of nano SiC particles on microstructure and thermal stability for AZ91 magnesium alloy were analyzed.The results show that grains of AZ91 magnesium alloy with nano SiC particles are refined greatly by copper-mould spray casting.Grain sizes can be refined to 5μm by copper mould casting with 2mm in diameter and 1% SiC nano-particles.SiC nano-particles play a role as a heterogeneous site under alloy solidification interface migration.Consequently,the combined effect refines grain size.As for the refined magnesium alloy after solid solution treatment at 400℃for different time,the average grain size of spray casted magnesium alloy with SiC particles is increased slowly,and it reaches only 12μm even after holding for 8h,indicating the effective increase of thermal stability for metastasable microstructure.关键词：Magnesium Alloy;Nano SiC Particles;Copper Mould Casting;Grain Refinement
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- 100
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- 1
发布时间：2023-12-18 - 摘要：The precipitates of Cu-0.6Fe alloy aged at 500 ℃for 0to 80 min was analyzed by small angle X-ray scattering technique.The results show that particle size of Fe phase is 4.55.9nm for Cu-0.6Fe alloy,which is in well agreement with the results（about 4.6nm）obtained by transmission electron microscope（TEM）.Compared with the transmission electron microscope measurement,the small angle Xray scattering technique has more statistical significance and more valuable.关键词：Small Angle X-ray Scattering;Precipitate Phase;Aging;Cu-Fe Alloy
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- 95
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发布时间：2023-12-18 - 摘要：The effects of aging treatment on hardness,electric conductivity,strength and elongation of cold rolling C194 copper alloy were investigated.The results reveal that with aging treatment at 450 ℃for 60 min,tensile strength,elongation,hardness and electric conductivity of the cold rolled C194 alloy reach 582 MPa,5.3%,170 HV and 41.47 MS/m,respectively,and the hardness,conductivity and strength are improved significantly compared with those of ones at continuous extrusion and rolling state,however,the elongation is decreased.After aging treatment,the number of second small particles in the alloy is increased significantly compared with that in continuous extrusion sheet,and the precipitates with about 1020nm are dispersed in the matrix.The size and number of the larger particles in the second phase are similar to that of the continuous extrusion sheet.The second phase precipitates and the growth phase are Fe3 P compounds.关键词：C194 Copper Alloy;Aging;Precipitated Phase;Cold Rolling
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- 160
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- 2
发布时间：2023-12-18 - 摘要：The effects of heat treatment on microstructure,electric conductivity and hardness of Cu-0.8Cr-0.15Zr-2.8Co-0.7Si-0.1RE alloy were investigated by optical microscopy,scanning electron microscopy,energy dispersive spectroscopy and X-ray diffraction.The results show that the as-cast microstructure of the alloy exhibits equiaxed grains,and a large number of Co5Cr3Si2 phase and gray precipitates containing Co,Si are distributed in the matrix.After solid solution treatment,the grain size is obviously increased,and the grey precipitated phase is fully dissolved,however,the Co5Cr3Si2 phase is not dissolved.After aging treatment,the precipitation particles are mainly Co5Cr3Si2,Co2Si phase.With the increase of solid solution temperature,electric conductivity of the alloy is decreased rapidly,while the hardness is increased rapidly.After aging treatment,the electric conductivity and hardness of the alloy are improved greatly.After 980 ℃×2h solution treatment+450 ℃×10h aging treatment,the hardness,electric conductivity and softening temperature of the alloy reach 218.9HV,28.54MS/m and 686℃,respectively.关键词：Cu-0.8Cr-0.15Zr-2.8Co-0.7Si-0.1RE Alloy;Electric Conductivity;Hardness
- 2
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- 79
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发布时间：2023-12-18
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