最新刊期
卷 34 ， 期 7 ， 2014
- 摘要：Morphology evolution of γ’ phase was investigated in a new nickel based single crystal during long-term aging. The results show that at 950、1 000 and 1 050 ℃,the phase morphology is evolved gradually into irregular strip shape,L shape and maze shape from initial cubical structure. The coarsening rate of phase in the interdendrite area is remarkably higher than that one in dendrite area. The coarsening rate is accelerated with aging temperature increase. The interfacial energy of γ /γ’ phase and the reduce of elastic strain energy are responsible for the phase coarsening and coarsening rate difference between the interdendrite and dendrite. The coarsening activation energy for phase in the interdendrite area and in dendrite area reach 345 kJ·mol- 1and 451 kJ·mol- 1,respectively.关键词：Nickel Based Single Crystal Alloy;Aging;Coarsening Behavior;Morphology
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发布时间：2023-12-18 - 摘要：Effects of Nd contents on microstructure and properties of quasi-crystal reinforced Mg-3. 0Zn-0. 6Y-0.6Zr alloy（ ZWK3） contained I-Mg3YZn6quasi-crystal were investigated by SEM（ scanning electron microscopy）,XRD（ X-ray diffraction）,tensile testing and dynamic thermo-mechanical analysis. The results reveal that Nd addition can increase eutectic phase content in the alloy,and with increasing in Nd addition,eutectic structure is transformed from lamellar structure into divorced eutectic structure with absence of quasi-crystal phase. Meanwhile,the mechanical properties of ZWK3 alloy contained Nd is slightly lower than those of the matrix alloy,however,tensile strength and elongation of the alloy are increased with increasing in Nd addition. With Nd addition,the damping behavior of the alloy is slightly improved,which can be described by G-L dislocation model.关键词：Magnesium Alloy;Nd;Quasi-Crystal;Mechanical Properties;Damping Behavior;G-L Model
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发布时间：2023-12-18 - 摘要：Effects of solid solution and aging treatment at varied temperature and time on microstructure and mechanical properties of Mg-Y-Nd-Gd-Zr alloy were investigated by optical microscope（ OM）,scanning electron microscopy（ SEM）,hardness tester and electron tensile machine. The results show that the intermetallic compound with size coarseness in as-cast Mg-Y-Nd-Gd-Zr alloy is reduced with increasing in temperature and time,and the optimized solution treatment is at 520 ℃ for 8 hours. Fine and dispersed intermetallic compounds are precipitated homogeneously,and the precipitated phase Mg-Y-Nd-Gd-Zr alloy is increased with aging temperature and time increase,which is responsible for improvement of microstructure and mechanical properties. After520 ℃ × 8 h solid solution treatment and hardness and 225 ℃ × 16 h aging treatment,the tensile strength and hardness of the Mg-Y-Nd-Gd-Zr alloy reach 271. 95 MPa and 78（ HV）,respectively.关键词：Mg-Y-Nd-Gd-Zr;Heat Treatment;Microstructure;Mechanical Properties
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发布时间：2023-12-18 - 摘要：The stabilizing temperature and time of the ZA35-0. 3Sr alloy were presented by electrochemical measurement of Tafel polarization curves,impedance spectroscopy test and microstructure analysis. The results show that the ε phase disappears due to dissolution into the matrix,and the non-equilibrium β phase at grain boundaries are eliminated after suitable stabilizing treatment for ZA35-0. 3% Sr alloy. The corrosion current density is reduced by 75. 69% and the corrosion resistance of the alloy is enhanced obviously compared with those of the alloy without treatment. The ZA35-0. 3Sr alloy with excellent corrosion resistance after stabilizing treatment is attributed to the increase of charge transfer reaction resistance and decrease significant of electrode electric double layer capacitor. The proper stabilizing treatment is at 350 ℃ for 4 h.
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发布时间：2023-12-18 - 摘要：<正>国内轴承铸造产业肩负着我国高端装备国产化的重要使命,在"十二五"规划的指导下,轴承铸造行业制定了行业发展的规划,制订了以项目和出口两驾马车拉动国内轴承铸造行业发展的方针。
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发布时间：2023-12-18 - 摘要：<正>2014年6月初,苏州工艺美术职业技术学院承担的文化部科技创新研究项目"苏州传统失蜡铸造工艺的挖掘与传承研究"通过成果验收。项目负责人、苏州工艺美术职业技术学院王汉卿副教授介绍,苏州传统失蜡铸造工艺的
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发布时间：2023-12-18 - 摘要：<正>据外电6月10日消息,HarborAluminumIntelligence总经理JorgeVazquez在芝加哥一会议上表示,今年全球铝市供应缺口料在117.6万吨,大于去年的45.8万吨。2015年铝产量缺口料将达108.6万吨,缺口最大的地
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发布时间：2023-12-18 - 摘要：<正>中国北车大连机车公司铸锻分公司日前成功试制出首批球墨铸铁叶片,并完成向北重阿尔斯通（北京）电气装备公司打包发货工作。这标志着大连机车公司填补了国内球墨铸铁叶片生产空
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发布时间：2023-12-18 - 摘要：<正>重庆在高强铝合金关键技术上取得重大突破,不仅填补了国内空白,还成功实现了产业化。高强铝合金具有密度低、强度高、热加工性能好等优点,其制成的板材、挤压型材、毂件等在航空航天构件上有
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发布时间：2023-12-18 - 摘要：<正>攻坚时期的机床铸造产业同时也是其从大到强的一个过程,对其行业发展相当重要。同时,"十二五"规划中对我国机床铸造产业也提出了明确的目标,即到2015年,机床铸造产业要实现工业总产值8 000亿元。
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发布时间：2023-12-18 - 摘要：<正>目前,由中钢邢机承制的4台500 t的连铸机设备轻压下装置,正在紧张进行生产,预计7月份交付日方客户使用。在双方共同召开的首次技术交底确认会上,来自日方的技术专家与中钢邢机技术人员仔细认真核对产品生产、组织管理和技术工作要求。
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发布时间：2023-12-18 - 摘要：The iron-cobalt-nickel alloy was smelted and prepared at 1 600 ℃ with the argon flow rate of 2 m3/h protective atmosphere,and then the sample was forged. With the help of optical observation,XRD（ X-ray diffraction） and hardness testing,the morphology and crystal structure of Fe-Co-Ni alloy were investigated. The results show that the iron-nickel-cobalt ternary alloy prepared exhibits uniformiy microstructure. After forged,the hardness can be increased by 28. 4 HV. The phases of Fe-Co-Ni alloy mainly consist of iron compounds and nickel compounds,such as FeN3or Fe64Ni36compounds. The Ni elements may be dissolved into CoFe compounds with low Ni content.关键词：Iron-Cobalt-Nickel Ternary Alloy;Smelting;Forging;Microstructure
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发布时间：2023-12-18 - 摘要：Interfacial heat transfer coefficient is an important boundary condition of casting process simulation,however,there is no accurate criterions for its value with relatively complicated calculation methods. In order to solve this problem,commercial simulation software for solving interface heat transfer coefficient was propsoed.Casting solidification temperature curves were measured,and the inverse module of ProCAST was used to calculate interfacial heat transfer coefficient between AC4B aluminum and H13 permanent mold. The results show that the interface heat transfer coefficient can be set to a function of temperature,and the commercial software to calculate interface heat transfer coefficient can meet project requirement.关键词：AC4B Aluminum;Numerical Simulation;Interface Heat Transfer Coefficient
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发布时间：2023-12-18 - 摘要：A electroslag remelting furnace with rotary mould was designed,and effects of the mould rotation speed on the degassing efficiency of Al2O3inclusion in electroslag remelting ingot were analyzed. The results show that when the mould rotating speed is in range of 0 28 r /min,the size of Al2O3inclusion is decreased gradually in electroslag ingot with the increase of mould rotating speed. The mould rotation can promote the refinement of metal droplet,enlarge the contact area between metal droplet with slag bath and improve dynamic condition of steelslag reaction. At the same time,slag bath movement can also drive the metal droplet to flow in the slag bath,which takes the longer route and longer delayed time in slag and accelerate steel-slag reaction. However,with the mould rotation speed further increased to 35 r /min,the inclusion size is increased,which is attributed to the higher mould rotation speed resulting in dramatical movement of metal bath and metal droplet to lead to involve the slag to metal bath and to decrease the ability of electroslag remelting to absorb the inclusion关键词：Electroslag Remelting;Mould Rotation;Inclusion
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发布时间：2023-12-18 - 摘要：An economical nickel-saving casting duplex stainless steel Cr25Mn10Mo4Ni2N was melt in mid-frequency induction furnace and was treated by solid solution treatment. The pitting corrosion property of treated steel was investigated by means of anodic polarization curve and electrochemical impendence spectroscopy（ EIS）.The corrosion resistance of Cr25Mn10Mo4Ni2N,2205 duplex stainless steel and 316L austenitic stainless steel in artificial seawater and simulated oilfield water as well as simulated formation water was evaluated comparatively.The results indicate that the nickel-saving casting Cr25Mn10Mo4Ni2N duplex stainless steel exhibits excellent anti-pitting corrosion property,and then 2205 duplex stainless steel,while the 316L austenitic stainless steel is the worst. The corrosion media of simulated formation water shows the strongest aggressive corrosion,followed by the simulated oilfield water,and the last is artificial seawater.关键词：Nickel-Saving Casting Duplex Stainless Steel;Pitting Corrosion Property;Artificial Seawater
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发布时间：2023-12-18 - 摘要：Effects of the both RE-Na /K and RE-Na /K-Ti compound modifier on the microstructure and properties of the high carbon-chromium alloy steel were investigated. The results show that both of the modifiers added in the high carbon-chromium alloy steel can refine the primary austenite effectively. The RE compound modifiers can play a obvious role in grain refinement,promoting network eutectic carbides dis-connection through constriction. Mechanical properties of the high carbon-chromium alloy steel are obviously improved,and hardness and impact toughness reach 41. 5HRC and 7. 6 J /cm2,respectively,increased by 2.9% and by 28.8% compared with the unmodified steel. Re-Na /K-Ti modified agent is superior to RE-Na /K modified agent in modification effects.关键词：High Carbon-Chromium Alloy Steel;Modification;Microstructure and Properties
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发布时间：2023-12-18 - 摘要：Semi-solid billet of ZA94 magnesium alloy was prepared by self-inoculation method（ SIM）. Influences of self-inoculants addition on semi-solid billet microstructure were investigated,and the mechanism of grain refinement was analyzed. The results show that the average grain size exhibits coarse with heterogeneous distribution when the inoculants addition is excessively more or less. The average grain size reaches 40. 2 45. 0 μm with 3% 5% self-inoculants addition. Nucleation particle in the melt is increased by adding inoculants,which plays a promoting role in heterogeneous nucleation. The addition of inoculants can directly affect own melting condition,and affect temperature fluctuations and energy fluctuations in the melt.关键词：Self-Inoculants;Grain Refinement;ZA94 Magnesium Alloy;Semi-solid Billet
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发布时间：2023-12-18 - 摘要：7075 aluminum alloy semi-solid billets were prepared by SIMA technology. Effects of holding temperature and holding time on microstructure of 7075 aluminum alloy thixotropic billets were analyzed. The results reveal that the desirable semi-solid structure in the thixotropic billets can be observed at 600 ℃ for 45 min or at615 ℃ for 15 min.关键词：7075 Aluminum Alloy;Thixotropic Alloy;SIMA
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发布时间：2023-12-18 - 摘要：6061 aluminum alloy was successfully processed by four-pass equal channel angular extrusion（ ECAE）through Bcroutes. Isothermal compression behavior was tested at strain rates ranging from 0. 05 to 1 s- 1and deformation temperate at 603 629 ℃. The true stress-strain curves were analyzed and semi-solid isothermal compression mechanism was described. Influences of deformation temperature and strain rate on the curves were analyzed. The results show that during the isothermal compression,solid-liquid separation occurs,and the flow stress of 6061 aluminum alloy is decreased with increasing in deformation temperature and increased with increasing in strain rates.关键词：6061 Aluminum Alloy;ECAE;Semi-solid;Isothermal Compression
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发布时间：2023-12-18 - 摘要：Taking an electrical accessory as a object,one module-two cavities pouring process was designed. Injection velocity,pouring temperature,mold temperature as affecting factors,the orthogonal scheme was designed. The testing results show that the influential order of the factors on the quality of casting are presented as follows: pouring temperature,mold temperature,injection velocity,where the optimized processing parameters are 0. 7 m /s injection velocity,620 ℃ of pouring temperature and 210 ℃ of mold temperature,and the lowest shrinkage porosity can be obtained.关键词：Orthogonal Experiment;Die Casting;Porosity;Processing Optimization
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发布时间：2023-12-18 - 摘要：The leakage defect of a aluminum alloy die casting clutch housing was analyzed,and the origination of the leakage was described. The porosity and die soldering were eliminated through some measures,such as optimizing the injection parameters,reducing the wall thickness and machining tolerance and adding the jet cooling in the die. The product quality was improved greatly.关键词：Al Alloy Die Casting;Clutch Housing;Leakage Defect
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发布时间：2023-12-18 - 摘要：Effects of solidification pressure under different pressurizing processes on the relative density of Al-Cu Alloy in vacuum counter-pressure casting were investigated through testing and analyzing the relative density across the ZL205A samples subjected to different solidification pressure. The results indicate that under singlecontrolled pressurization of vacuum counter-pressure casting,the relative density of different wall samples is improved with the increase of solidification pressure. Changing trend of the density exhibits V shape from gate to the top,moreover,the relative density is much more homogeneous with the increase of solidification pressure. Meanwhile,the relative density under grade-controlled pressurization is higher than under single-controlled pressurization. Under the same solidification pressure,the relative density is increased with the increase of wall thickness.关键词：Vacuum Counter-Pressure Casting;Pressurizing Process;Solidification Pressure;Density;Al-Cu Alloy
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发布时间：2023-12-18 - 摘要：Large aluminum flange is manufactured commonly by sand mold casting for releasing and feeding difficulties. To improve product efficiency and quality,decrease surface roughness,a larger aluminum alloy flange with multi lightening holes was produced by metal mold low pressure casting,realizing continuous production.The 24 lightening blind holes in the aluminum alloy flange adopted iron-core fixture and dis-fixed core-pulling method. Wind-blowing for the metal mold was conducted to accelerate the cooling velocity. Through setting lower-cold iron,designing"reversen"gate and canceling ceramic sleeve as well as shortening feeding distance of riser and increasing solidification,feeding capacity of aluminum alloy flange was improved.关键词：Metal Mould;Low-pressure Casting;Feeding Distance;Iron Core;Sand Core;Chiller
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发布时间：2023-12-18 - 摘要：A new forming method that is flexible thixo-extrusion is put forward to form three-dimensional variable cross-section complicated components. The forming process was simulated by the FEM software DEFORM-3D to present flow velocity field,equivalent strain field and the load-stroke curve. And the flow behavior,strain distribution of the blank and the change of the extrusion force with extrusion stroke of the punch were analyzed. The results indicate that it is feasible to form the three-dimension variable cross section parts using the flexible thixoextrusion. And compared with the conventional extrusion,the flexible thixo-extrusion presents an obvious advantage in the forming quality of the components.关键词：Three-Dimension Variable Cross Section;Flexible Thixo-Extrusion;Numerical Simulation
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发布时间：2023-12-18 - 摘要：Through using ANSYS finite element analysis software to simulate the driving process of electromagnetic induction type cylindrical pump to liquid metal,intensity distribution in the magnetic induction electromagnetic pump and the exerting force of liquid metal were analyzed. By comparing the simulated results at different number of poles,the number of pole core and power frequency,the optimized design parameters were presented to conduct experimental verification. The results reveal that at a given current circumstances,the electromagnetic pump with two poles can excite a higher liquid pressure,and the electromagnetic force is increased with the increase of the number of the pole core and the power frequency.关键词：Induction Type;Electromagnetic Pump;Number of Poles;Pole Core;Frequency
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发布时间：2023-12-18 - 摘要：<正>"2014第九届中国（上海）国际有色金属工业展览会（CINME 2014）"将于2014年10月14日-16日在上海新国际博览中心举行。作为国际有色金属领域最具影响力的盛会之一,CINME由北京海闻展览有限公司联合权威机构共同举办,历经九年的发展创新,品牌化、专业化、国际化程
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发布时间：2023-12-18 - 摘要：From summarizing molding design and practical experiences on production,molding structure and process of lost foam pattern design were described,which taken less deformation and size foam consistence. In addition,pattern-removal was smooth with high strength,reducing the labor intensity and increasing the molding efficiency,ensuring the casting size accuracy and desirable surface.关键词：Lost Foam Casting;Transmission Housing;Molding Design
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发布时间：2023-12-18 - 摘要：Investment casting process design often encounter some problems such as complex structure or hot section dispersed,and difficult to put the gate. According to the product experience,some processing ways with gate-free were presented to eliminate shrinkage porosity,such as using water to cooling local shell,setting the cold iron and hot subsidies,brushing special coating as well as using chromite sand,improving the ability of eliminating shrinkage porosity in the product process design.关键词：Shrinkage Porosity;Water Cooling Local Shell;Cold Iron;Hot Subsidies;Chromite Sand
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发布时间：2023-12-18 - 摘要：Welding-repair failure of aluminum alloy parts produced with gypsum mould by investment casting combining with vacuum pouring and solidification under pressure were analyzed. The results show that excessive hydrogen absorbed in the refining process can migrate towards the oxides and Al2O3double membrane in the process of solidification. During welding repair at defect surface of the upper castings,hydrogen concentration around the repair welding areas partially plays toward the Al2O3double membrane with the temperature increases,leading to the double membrane rupture to failure of welding repair as a result of pressure increase. By the degassing treatment and density measurement method,the hydrogen content in the Al alloy melt was controlled in a certain range,and failure of welding-repair could be improved.关键词：Gypsum Mold;Welding Repair;Vacuum Pouring;Pressurized Solidification
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发布时间：2023-12-18 - 摘要：Influences of different magnetic field intensity and pulsed frequency on solidified structure and mechanical properties of Mg97Y2Cu1alloy reinforced by long period ordered structure were investigated under direct current pulsed magnetic field（ DCPMF）. The results show that morphology and volume fraction of the second phase are changed. When the magnetic field intensity is at 0 0. 25 T,with the increase of magnetic field intensity,primary phase in the alloy is refined gradually,and the size and volume fraction of second phase are increased. When the pulsed frequency is at 1 5 Hz,effects of pulsed frequency on primary phase and second phase can be ignored. With the pulsed frequency increasd to 10 Hz,the desirable refinement effect of primary phase can be observed,and the second phase with the highest volume fraction is distributed uniformly into the matrix. With the increase of magnetic field strength or pulsed frequency,both the strength and elongation of the alloy are increased gradually. When the magnetic field intensity is 0. 25 T,tensile strength and elongation of the alloy are increased by 42. 5% and by 106. 0%,respectively,compared with the alloy in traditional condition.关键词：DC Pulsed Magnetic Field;Mg97Y2Cu1;Long Period Ordered Structure;Solidified Structure
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发布时间：2023-12-18 - 摘要：Effects of solid solution and aging treatments on the microstructure of Mg-2Er-1Zn-0. 18Zr（ atom. %）were investigated by optical microscope（ OM）,XRD（ X-ray diffraction）,SEM（ scanning electron microscopy）,EDS（ energy dispersedly spectrometer） and microhardness testing. The results show that the microstructure of as-cast Mg-2Er-1Zn-0. 18Zr alloy is composed of α-Mg phase and X-Mg12ErZn phase. After solid solution treatment at 540 ℃ for 32 h,the X-Mg12ErZn phase is completely dissolved into the matrix phase with precipitation of W-Mg3Er2Zn3phase,however,the coarseness of grain size is absent. Compared with that of solid solution alloy,the obvious change of microstructure and micro-hardness of the alloy after aged treatment at 180 ℃ can not be observed,which is composed of α-Mg phase and W-Mg3Er2Zn3phase also.关键词：Mg-2Er-1Zn-0.18Zr Alloy;Solid Solution;Aging;Microstructure
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发布时间：2023-12-18 - 摘要：Ti-Ni diffusion couples with curving interfaces were prepared by mechanical method. The heat treatments of diffusion couples were carried out at 500 700 ℃ in vacuum annealing furnace. The interface diffusion of Ti-Ni diffusion couples were observed with different vacuum sintering time at 500 700 ℃ by means of color metallograph. The results show that the thickness of diffusion layer is increased with the increase of sintering temperature and holding time. And the diffusion layer is composed of different sublayer.关键词：Ti-Ni Diffusion Couples;Phase Interface;Diffusion Layer;Intermetallic Compound
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发布时间：2023-12-18 - 摘要：The heat treatment of 7075 Al alloy used for engine rocker arms was carried out,and the microstructure,mechanical properties and stress corrosion resistance of 7075 Al alloy at different aging conditions were investigated. The results show that after T6 treatment,the strength of Al alloy reaches the maximum value while electrical conductivity exhibits low which takes bad stress corrosion resistance. After orthogonal optimization two-stage aging treatment,the strength of alloy is decreased slightly while electrical conductivity is increased obviously. The stress corrosion resistance is improved with the decrease of the time and cost for manufacture,improving the production efficiency. The optimized heat treatment process is（ 460 ℃ × 1 h） +（ 105 ℃ × 8 h + 160 ℃ × 8 h）.关键词：Engine Rocker Arms;Heat Treatment;Stress Corrosion Resistance
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发布时间：2023-12-18 - 摘要：Influences of alloying elements Cu,Mn and Ni on the microstructure and mechanical properties of ZL109 piston alloy were investigated. The results show that Cu can promote the precipitation of stripped Al3CuNi and skeleton like Al7Cu4Ni phases,which are responsible for gradually increase of tensile strength of alloy at room temperature and 300 ℃. Ni can also promote the precipitation of Al3CuNi and Al7Cu4Ni phases,however,the change of mechanical properties at room and high temperature can be ignored. With the Mn content of 0.15%,the tensile strength at room and high temperature reaches peak value. With increasing Mn to 0. 30%,the tensile strength is decreased,which may be relate with the morphology of Mn-containing phase and its high temperature stability. It can be considered that the optimization compositions are 1. 0% Cu,0. 7% Ni,and 0. 15%Mn in ZL109 piston alloy.关键词：ZL109;Piston Alloy;Composition Optimization;Microstructure;Tensile Property
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发布时间：2023-12-18 - 摘要：Effects of low voltage pulsed magnetic field（ LVPMF） on the solidified microstructure and damping capacity of A357 alloy were investigated. Experimental results show that primary α-Al phase and eutectic Si phase in A357 alloy treated by LVPMF are refined significantly. A357 alloy treated by LVPMF exhibits much higher damping Capacity than that untreated by LVPMF. Moreover,damping capacity is increased with increasing in temperature,whereas decreased with increasing in frequency. At room temperature,strain amplitude of 0. 01%and frequency of 1 Hz,the damping capacity value reaches 0. 0142 for A357 alloy with LVPMF treatment. Compared with the A357 alloy without LVPMF treatment,the damping capacity value is increased by approximately170%. With increasing in frequency,damping capacity of T6-treated A357 alloy after LVPMF treatment is decreased gradually.关键词：Low Voltage Pulsed Magnetic Field;A357 Alloy;Microstructure;Damping Capacity
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发布时间：2023-12-18 - 摘要：Effects of solution temperature,aging time,aging temperature on microstructure and mechanical properties of cast Al-Cu-Mn aluminum alloy were investigated by optical microscopy,SEM（ scanning electron microscopy）,tensile testing and hardness measurement. The results show that the least residual phase in the grain boundary occurs after solution at 530 ℃ for 14 hours. The hardness of samples aged at 170 ℃ reaches the maximum value of 145 at the sixth hour,and then decreased with increasing in aging time. The tensile strength and hardness of samples with aging at different temperatures for 6 hours are increased firstly and then decreased with increasing in temperature. The tensile strength and hardness of the samples at 170 ℃ reach 480 MPa and 145（ HBW）,respectively. However,the elongation is decreased rapidly with increasing in aging temperature.关键词：Cast Aluminum Alloy;Solution;Aging;Microstructure;Mechanical Properties
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发布时间：2023-12-18 - 摘要：Through orthogonal experiment and adopting numerical simulation combining with practical pouring,effects of some factors,such as cylindrical cavities diameter,slit gate width and thickness,on filling and solidification process of aluminum alloy castings were investigated. The experimental results show that when the thickness of slit gate is 1 times of parts wall-thickness,and slit gate width is 35 mm,and cylindrical cavities diameter is 3 4 times of slit gate thickness,the filling process can be ensure to obtain good casting quality.关键词：Al Alloy Castings;Slit Gating System;Numerical Simulation
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发布时间：2023-12-18 - 摘要：<正>近日,德国西马克-梅尔公司与山东省四方技术开发有限公司在济南签订一笔包括9套ERW焊管轧辊在内的大额出口订单。这是继去年12月德国客户试探性订货,经发往国外严格检测和上机试验确认后,德国公司专程前来
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发布时间：2023-12-18 - 摘要：The deformation behavior of Zn-Cu-Ti alloy was investigated by compression tests on the Gleeble-1500D thermal simulator machine under the condition of the temperature at 150 240 ℃ and the strain rate at0. 01 10 s- 1as well as the reduction of 50%. Microstructure evolution during compress was observed by optical microscope. The result show that the dynamic recrystallization occurs during hot compression deformation.Characteristics of the true stress-true strain curves are different with different deformation conditions. The maximum flow stress is decreased with the increase of deformed temperature and decrease of strain rate. The flow stress model can be described by a constitutive equation in the form of Arrhenius function. Two safety zone in the temperature of 150 210 ℃,strain rate at 0. 67 10 s- 1and in the temperature of 215 240 ℃,strain rate at0. 01 0. 98 s- 1was presented based on processing map under the condition of the experiment. The optimum domain for hot working occurs at 235 240 ℃ and 0. 09 0. 11 s- 1with the efficiency of power dissipation of35%.关键词：Zinc Alloy;Flow Stress Model;True Stress-Strain Curve;Hot Processing Map
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发布时间：2023-12-18 - 摘要：Effects of adding method and addition content of niobium element on the microstructure,thermal conductivity and melting point of the Cu-Ni-Nb alloy were investigated by vacuum arc melting process. The results show that it is difficult to mix the high melting point element Nb into Cu-Ni alloy only by one smelting. However,the Nb element can be dissolved into the Cu-Ni alloy in style of Nb-Ni master alloy by using two steps melting.Some new phases such as Ni3Nb,Ni8Nb are generated. In addition,with the increase of Nb content,the thermal conductivity the Cu-Ni-Nb alloy prepared is increased while the melting point of the alloy is decreased. The thermal conductivity of Cu-20Ni-3Nb alloy reaches 43. 23 W /（ m·K）,and the melting point is 1 146 ℃.关键词：Cu-Ni-Nb Alloy;Microstructure;Thermal Conductivity
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发布时间：2023-12-18 - 摘要：Three-dimension modeling of flow field in the molten pool of double-roller continuous casting strip was established at a common condition with the help of the ANSYS software,and the transient simulation of the wavesurface of the molten pool was visualized. Relationship of the average height of the contact-line between the wave surface and the roller on the position of the corresponding point has been derived,combined with the effect of the wave height in the zone of the end of the molten pool. Analysis of the value and tendency of the effect graph was conducted.关键词：ANSYS;Continuous Strip Casting;Wave Surface;Transient Simulation
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发布时间：2023-12-18 - 摘要：MgO /Cu composites with different MgO content such as 1%,3%,5%,8%,were prepared by SPS（ spark plasma sintering） method. Influences of different MgO volumetric fraction on density、electric conductivity,hardness and microstructure of the composites prepared were investigated. Arc erosion resistance was tested by JF04C electrical contact material testing system. Experimental results show that with the increase of MgO volumetric fraction,density and electric conductivity are decreased,meanwhile,the hardness is increased firstly and then decreased,and the weight loss is decreased and arc erosion resistance is improved. With MgO content of 5%,comprehensive properties of MgO /Cu composites exhibit desirable,where hardness is 110 HV and conductivity is 45. 24MS /m with electrical erosion resistance of 0. 1 mg. The microstructural observation reveals that with MgO content in range of 1% to 5%,MgO particles are uniformly distributed into the matrix with fine grain and decrease of contact surface melting degree. When the MgO volume fraction is 8%,MgO particles in copper matrix present a certain aggregation,leading to the comprehensive performance changes of MgO /Cu composites.关键词：SPS;MgO /Cu Composites;Conductivity;Hardness;Arc Erosion Resistance
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发布时间：2023-12-18
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