最新刊期
卷 39 ， 期 12 ， 2019
- 摘要：AlxCrCuNiTi（x=0.2, 0.4, 0.6, 1.0） high entropy alloys were prepared by arc melting process. The microstructure and hardness of the alloys prepared were characterized by X-ray diffraction（XRD）, scanning electron microscopy（SEM） and digital display Vickers hardness tester. The results reveal that the alloys are composed of a mixed structure of BCC1, BCC2 and FCC phases. With the increase of Al content, the FCC phase is decreased and the BCC phase is increased, which indicate that the Al element is in favor of the formation of BCC phase. The microstructure of the alloys presents a structure of dendrite and interdendrite. With the increase of Al element, the dendrite region is reduced while the interdendrite region is expanded in the AlxCrCuNiTi high entropy alloys. In addition, Al, Cr and Ti are segregated in the dendrite region, while Cu and Ni are segregated in the interdendrite region. The hardness of the AlxCrCuNiTi alloys is increased to 513 HV from 376 HV as the increase of Al content.关键词：High Entropy Alloy;Microstructure;Hardness
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发布时间：2023-12-18 - 摘要：Mg-39 Bi-17 Sn alloy was selected as the heat storage material, and 45 steel, 201 and 316 L stainless steel were used for the container materials. By constant temperature full immersion corrosion testing, the corrosion behavior and mechanism of three steels in Mg-Bi-Sn alloy liquid were investigated with the aid of metallographic microscope, XRD analyzer and electron probe（EPMA） combined with corrosion kinetics analysis. The results reveal that the corrosion rates of 45 steel, 201 and 316 L stainless steel reach 0.559, 0.557 and 0.072 g/（m2·h） after 840 h corrosion, respectively. There exists obvious corrosion layer at the boundary of 45 steel, and the thickness is about 10～15 μm. The corrosion layer consists of Fe3O4 and Fe. There is absence of obvious corrosion layer at the edges of 201 and 316 L stainless steel. The 45 steel contain the free of Ni or Cr, so it is difficult to prevent the corrosion of O element in the molten metal. In the 201 stainless steel, the Ni content is low, so it is difficult to fully exert the corrosion resistance of Cr element. The Mo element in 316 L and Cr has synergistic effect, further strengthening the corrosion resistance of 316 L stainless steel.关键词：Mg-Bi-Sn Alloys;Phase Change Thermal Storage;Stainless Steel;Compatibility
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发布时间：2023-12-18 - 摘要：Microstructure and damping properties of ZK60 magnesium alloy sheet after heat treatment were investigated by means of metalloscope and multifunctional internal friction meter. The results reveal that the change of grain size is absent after T5 heat treatment, while it is increased significantly after T4 or T6 heat treatment. In addition, the content of the second phase is increased significantly after T5 and T6 heat treatment. There exist two damping peaks in the temperature-damping spectra of T4 and T6 heat treatment, where P1 peak is grain boundary internal consumption peak, and P2 peak is recrystallization damping peak, and P1 peak is inhibited in rolling state and T5 heat treatment, while P2 peak is higher than that in T4 and T6 heat treatment because of many substructures. Moreover, the second phase particles have a certain strengthening effect on grain boundary, which leads to the increase of activation energy in grain boundary.关键词：Heat Treatment;ZK60 Magnesium Alloy;Damping Peak;Damping
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发布时间：2023-12-18 - 摘要：The AlSi10 MnMg longitudinal beam was produced according to the Flow-3 D simulation results, and the as-cast microstructure was observed and analyzed for typical positions. The metallography reveals the typical defects including segregation, air entrapment, shrinkage and oxide inclusion. According to the distribution and microstructure of the defects, the countermeasures were presented to reduce the casting defects. The alloying element can be distributed uniformly in the alloy through stirring the melt. Oxide inclusions can be decreased by adopting dense filter. Shrinkage porosities can be reduced through extending hold pressure time. Air-entrapment defects can be declined through optimizing gating system or using vacuum die casting.关键词：AlSi10MnMg Alloy;Die-Casting;Defect Analysis;Flow-3D Software
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发布时间：2023-12-18 - 摘要：A two-dimensional steady laminar flow model was established by using Fluent software. The casting-rolling simulation of copper-aluminium clad plates with different thickness was carried out by choosing blank traveling speed of 0.5 m/min and pouring temperature of 973 K. The results show that with a given thickness of the aluminium layer, the temperature at the exit of the casting-rolling zone and the ratio of liquid cavity depth are increased with the decrease of the thickness of the copper layer. With a given thickness of the copper layer, the temperature at the exit of the casting-rolling zone and the ratio of liquid cavity depth are decreased with the decrease of the thickness of the aluminum layer. The casting-rolling process was carried out with Cu layer thickness of 8 mm and aluminum layer thickness of 2 mm. The interface scanning and energy spectrum analysis was carried out by SEM and EDS. The casting-rolling composite mechanism of copper-aluminium composite plate was expounded.关键词：Cu-Al Clad Plates;Continuous Cast-Rolling Forming;Numerical Simulation;Compound Mechanism
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发布时间：2023-12-18 - 摘要：<正>近日,力劲集团智能压铸高新科技项目开工仪式,在深圳市深汕特别合作区举行。项目将建成力劲集团的一个新的压铸机生产、研发基地。据悉,力劲集团智能压铸高新科技项目,位于深圳市深汕特别合作区,占地150多亩,总投资4亿元,将建设2栋生产厂房、1栋综合楼、2栋宿舍楼及相应配套工程。项目建成后,将是力劲智能压铸岛、精密压铸机、压铸工业机器
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发布时间：2023-12-18 - 摘要：<正>近日,株冶新材顺利向客户交付首批铸造用锌合金63t,这标志着株洲冶炼集团股份有限公司最大的转型项目——火炬新材锌基合金项目投产上线工作取得成功。2019年3月7日,株冶火炬新材锌基合金项目在湖南省株洲市渌口区南洲工业园破土动工,建设产能30万t的锌合金生产基地。随后,该锌合金生产基地铸造锌工序3-2号线点火烤炉。据了解,该基地现已建设成为热镀锌合金20万t、铸造用锌合金10万t的锌合金生产基地,是目前国内最大的锌合金生产基地。该锌合金生产基地拥有国
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发布时间：2023-12-18 - 摘要：<正>近日,艾斯迪（芜湖）材料技术有限公司奠基仪式在芜湖经济技术开发区举行。公司将依托亚新科（天津）汽车零部件有限公司合金铸造技术及汽车轻量化解决方案的能力,建设轻量化新材料技术高精密汽车零部件制造、研发及区域总部项目。据了解,项目总投资4.6亿元,总建筑面积为约3.8万m2,主要建设机加工车间、铸造车间、生产车间、备货区车间、辅料库等设施,生产进气歧管、油底壳、差速器壳、正时
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发布时间：2023-12-18 - 摘要：<正>近日,包头铝业在国内率先成功研发并批量生产某型号新型铝合金。该铝合金主要用于生产汽车发动机活塞和军用车辆大功率发动机的活塞,有效填补了国内空白。据悉,此前国内生产大功率发动机活塞所需的铝合金材料几乎全部依靠进口。为填补这一空白,包头铝业与中国兵器工业集团某研究所共同立项进行研究,经过一年多的努力,成功开发出某种型号的新型铝合金。通过调整铜、镍等合金元素的含量,
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发布时间：2023-12-18 - 摘要：<正>近日,由中国科学院金属研究所负责研制的全海深载人潜水器钛合金载人舱通过验收。据悉,全海深载人潜水器是我国自主研发建造的全新一代载人潜水器,该潜水器建成后,将在世界最大深度（约11km）的海洋完成载人下潜并进行科考作业,是深海进入能力的顶级体现。载人舱是全海深载人潜水器的核心部件,要求质量轻、强度高、可焊接、耐腐蚀、抗疲劳、长寿命,对材料的大规格制备能力和综合力学性能有着很高的要
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发布时间：2023-12-18 - 摘要：The gravity casting process of aluminum alloy wheels was simulated by the ProCAST software. The effects of shrinkage porosities, temperature field and solid phase rate on the quality of wheel castings were analyzed. The location and origination of defects in the aluminum alloy wheel hub were analyzed. The improvement measures such as adding cold iron and insulation coil were proposed. The results show that the improved process can reduce effectively casting defects.关键词：Aluminum Alloy;Gravity Casting;Wheel Hub;Numerical Simulation
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发布时间：2023-12-18 - 摘要：The gas hole could be observed in the top end of air intake side bolt stud of tilting gravity casting aluminum alloy cylinder. The produced-scrapped rate during the first production reaches up to 44%. The filling and solidification during casting process were simulated by AngCasting software, and origination of blowhole defect was analyzed. Through comprehensive considering the casting parameters and mold structure design, the formation of gas hole is attributed to the releasing gas of heated sand cores of water channel and air channel. Hence based on the simulated result, the venting structure on bottom mold was designed. The blowhole defects can be absent after producing 30 cylinders using the modified design.关键词：Aluminum Alloy Cylinder Head;Tilting Gravity Casting;Sand Core Gas Volume;Blowhole;AnyCasting
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发布时间：2023-12-18 - 摘要：<正>日本政府计划最早于2020年开始联合日本海洋研究开发机构等,利用自主式无人潜艇（AUV）调查位于小笠原诸岛南鸟岛的深海之中的稀土储量。调查将确认海底包含高浓度稀土的地层,力争掌握稀土的准确储量。据称,如果此次调查成功,将是世界上首次使用自主式无人潜艇调查稀土储量的行动2013年,研究小组在南鸟岛近海的海底发现含有高浓度的稀土泥。此后,他们使用调查船在南鸟岛以南250km海底（深度为5 600m）的25处地方采样,估算资源面积约为2 400km2,总蕴藏量约为1 600万t,其中含有金属铽
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发布时间：2023-12-18 - 摘要：<正>近日,韩国成均馆大学裴宗玉（音译）教授研究团队成功开发出一项化学工艺,利用氧化铝和铜制备成纳米结构的合成催化剂,可实现从二氧化碳中提炼出有用的石化中间体——二甲醚。据了解,从二氧化碳中制备甲醇和二甲醚等中间体,可以合成生产出不同的石油化工原料,在石油资源日益枯竭和地球温室化步伐加快的今天,实现二氧化碳的综合循环利用。实际上,此前已经有技术实现了从二氧化碳中制备甲
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发布时间：2023-12-18 - 摘要：The filling and solidification process of the aluminum alloy front cover of the car engine were simulated by using Magma software. According to the simulated results, the optimized die casting process was designed, and filling and solidification process were simulated based on the modified design. The change of the temperature, air pressure and solidification of the castings were simulated, and the rationality of the optimized process was verified. Aimed to the problems of the high temperature and slow cooling of the partial area, high pressure point cooling was adopted to promote the cooling rate, improving the quality of the casting. Finally, the feasibility of the gating systems design was verified by the die casting production.关键词：Engine Front Cover;Numerical Simulation;Die Casting Process;Process Optimization
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发布时间：2023-12-18 - 摘要：The aluminum alloy automobile steering knuckle with 400 MPa in strength was manufactured by squeezing casting. Through optimizing Al-Si-Mg-Cu alloy composition, squeezing casting parameters and designing and manufacturing squeezing mould, high strength aluminum alloy steering knuckle was developed successfully, where tensile strength, yield strength, elongation and hardness reached 454.6 MPa, 409.2 MPa, 6.2% and 137.2, respectively.关键词：Steering Knuckle;Squeezing Casting;Al-Si-Cu-Mg Alloy;Mechanical Properties
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发布时间：2023-12-18 - 摘要：Shell as a part of the engine cylinder head cover, after several generations of product integration and update, its die casting technology has become more complex, so the defect types and location distribution are more dispersed. In order to reduce defects in the production and manufacture process, at the early stage of the development, numerical simulation method was applied to understand accurately the aluminum liquid filling state and the distribution of the casting defects, greatly shortening the mold development cycle. Cylinder head cover shell parts were trial-produced with high vacuum die casting technology and common die casting. Through analyzing casting quality, it is found that the high vacuum die casting can produce the qualified cylinder head cover at the lower injection velocity and pressure.关键词：Cylinder Head Cover;Numerical Simulation;Filling;High Vacuum Die Casting;Defect
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发布时间：2023-12-18 - 摘要：The wettability of metal/ceramic systems is one of the decisive factors in the structure and properties of cermets. Based on the classification of wettability of cermet system, the factors affecting the wettability of the system were described. The wettability of cermet systems is divided into non-reactive wetting and reactive wetting, wherein reactive wetting is further divided into redox and wet wetting. The factors affecting the wettability of cermet system are mainly the surface roughness and grain orientation of the ceramic substrate, the protective atmosphere, the alloying element content, the holding temperature and the ceramic matrix processing method.关键词：Cermet;Wettability;Contact Angle
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发布时间：2023-12-18 - 摘要：The small ZG16 Cr2 MnTi alloy steel aerospace bracket with a higher dimension accuracy was produced in small batch by investment casting. Gas hole, slag inclusion and shrinkage hole often occur in the castings of the initial design in actual production. After simulation and analysis, and combined with practical experience, the design was modified. The wax pattern was assembled by in turnover 180° and was declined down to 10° to realize tilting tope pouring. Through adopting cavity declination and turnover assembling design, the qualified rate the investment casting bracket was improved greatly.关键词：Bracket;Investment Casting;Process Optimization;Numerical Simulation
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发布时间：2023-12-18 - 摘要：Thermophysical properties of CL162 type wax were measured experimentally. Then the injection process of the wax pattern with circular structure was simulated by the Moldflow software. Meanwhile, wax injection experiment based on the simulated model was carried out to evaluate the simulated ones. The results reveal that the viscosity of the wax is reduced rapidly as the temperature or the shear rate rises, presenting the typical behavior of non-newtonian fluid. The simulation of wax injection process reveals the details of the filling process. Surface depression, volume shrinkage and deformation were predicted. Measurement data of experimental wax patterns is well-fitted with the simulated ones, which verifies the accuracy of the simulation.关键词：Numerical Simulation;Thermophysical Properties;Wax Injection;Shrinkage and Deformation
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发布时间：2023-12-18 - 摘要：A set of information visualization method suitable for the workshop site of titanium alloy investment casting enterprise was presented, which was based on InterCast ERP/MES/PDM integrated system, including the visualization method of production, process and quality in the whole process of mould-making, shell-making, melting and pouring, fluorescence inspection and X-ray inspection. The application cases of typical products in the whole process were presented, so as to provide a reference for the construction of workshop informatization in foundry industry.关键词：Titanium Alloy;Investment Casting;Information Technology;Visualization Method
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发布时间：2023-12-18 - 摘要：The velocity field and temperature field of liquid metal in the filling process of a heavy-duty gas turbine blade were simulated by the ProCAST software. The formation mechanism of misrun defect and the influence behavior of process parameters were described. The results reveal that the defect of misrun is caused by the excessive heat loss of liquid metal during the filling process, which is essentially attributed to the filling order, filling track and heat exchange affecting the temperature distribution of the liquid metal. In addition, the result also found that the scale of misrun defects can be improved with increasing in pouring temperature. The filling sequence and path can be changed with increasing filling rate, however not necessarily improve heat exchange status and misrun defects. The filling sequence, filling path and heat exchange of liquid metal can be fundamentally controlled by optimizing design of the gating system and reasonably controlling the casting parameters, thus effectively avoiding the defect of misrun.关键词：Industrial Gas Turbine;Filling;Numerical Simulation;Misrun
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发布时间：2023-12-18 - 摘要：The problems in crystal grain defect, airfoil swelling and over size as well as platform porosity were described. These problems were resolved effectively by decreasing pouring temperature, adoting composite ceramic shell, wrapping aluminium silicate fiber as well as optimizing wax and shell making parameters, using anti-deformation processing rib, shell making rib and partial enhancing shell.关键词：Large-size Double-blade;Grain Deviation;Dimensional Deviation;Porosity
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发布时间：2023-12-18 - 摘要：The causes of abnormal microstructure and inclusions in the centrifugal casting wearing ring were analyzed.The abnormal microstructure and inclusions were eliminated by selecting the optimized discharge time, inoculation process, the thickness of coating and optimizing melting and heat treatment process.The yield of wearing ring was increased.关键词：Wearing Ring;Centrifugal Casting;Abnormal Microstructure;Inclusion
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发布时间：2023-12-18 - 摘要：SPH（smoothed particle hydrodynamics） method was used to simulate the filling process of vertical centrifugal casting. The three-dimensional mathematical model based on SPH vertical centrifugal casting filling process was established and calculated by hydraulics. The feasibility of the model was verified by using the mathematical model established. The actual casting filling process was simulated and compared with the ProCAST simulation ones. The practicality of the mathematical model and development program established was further explained.关键词：SPH;Three Dimensional Numerical Simulation;Vertical Centrifugal Casting;Filling Process
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发布时间：2023-12-18 - 摘要：The decrease of oxygen content and crack in oxygen-free copper ingots were analyzed. Firstly, through the development of an integrated holding temperature smelting furnace, the holding temperature and melting process were integrated into the whole. Therefore, the traditional three-stage fabrication method of alloy copper was modified into a two-stage fabrication method of holding smelting and drawing casting of anaerobic copper. Secondly, the gate valve technology of controlling melt flow and stopping was proposed and realized. Thirdly, the crack of anaerobic copper ingot with width/thickness ratio of 650 mm/20 mm was analyzed. Finally, the reasonable cooling parameters were determined through experiments. With ingot oxygen content ≤0.000 4% and density increased to 8.94～8.95 g/cm3, crack is completely eliminated.关键词：Horizontal Continuous Casting;Oxygen-free Copper Ingot;Oxygen Content;Density
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发布时间：2023-12-18 - 摘要：6013 aluminium alloy ingot with 210 mm in diameter was prepared by low frequency electromagnetic field semi-continuous casting. The effects of electromagnetic field frequency on microstructures and mechanical properties of the ingot were investigated by optical microscope, scanning electron microscope, electron probe micro analysis and tensile testing machine. The results reveal that the low frequency electromagnetic field can refine the α-Al grains in the aluminum alloy ingot and increase the number of fine second phases as well as increasing the content of elements in the grain, so improving tensile properties of the ingot. With increasing in electromagnetic field frequency, the α-Al grains are converted gradually from coarse dendrites to fine grains, and the grain size and the second phase are gradually uniform distribution, so tensile properties of the ingot edge are improved gradually. Compared with the ingot without low frequency electromagnetic field, tensile strength, yield strength and elongation of the ingot edge are increased by 9.62%, 8.36% and 62.89%, respectively, when the frequency of electromagnetic field is increased to 40 Hz.关键词：6013 Aluminum Alloy;Semi-continuous Casting;Low Frequency Electromagnetic Field;Grain Refinement
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发布时间：2023-12-18 - 摘要：The cylinder is difficult to manufacture because of its complex structure and high manufacturing accuracy. In order to assure quality and reduce the waste products rate, it should be analyzed from aspects of raw materials, chemical composition of liquid iron, inoculants selection and processing selection, product processing control.关键词：Cylinder;Casting Processing Design;Ductile Iron
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发布时间：2023-12-18 - 摘要：In the dry friction condition, the sliding friction and wear characteristics were investigated of the grey cast iron and the untreated high-carbon equivalent alloy gray cast iron with high carbon equivalent alloy under different loading and friction time with the semi-metallic material as the sub-metallic material. The results reveal that compared with the untreated ones, the nitrocarburized high carbon equivalent alloy gray cast iron presents high friction coefficient and good stability, and the wear resistance is desirable, especially under the condition of large load and long time. The wear types of untreated high carbon equivalent alloy gray cast iron under low load are characterized by adhesive wear accompanied by slight three-body abrasive wear, and by serious adhesive wear and fatigue spalling wear under high load. The wear mechanism of nitrocarburized high carbon equivalent gray cast iron presents mild oxide three-body abrasive wear under low load and fatigue spalling wear under high load.关键词：High Carbon Equivalent Alloy;Nitrocarburizing;Fatigue Peeling Wear;Frictional Wear
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发布时间：2023-12-18 - 摘要：Al2O3/7075 composites were prepared by ball milling precast block and high-energy ultrasound method, and effects of solid solution treatment on the microstructure and mechanical properties of Al2O3/7075 composites were investigated by SEM, EDS, hardness and tensile testing. The results reveal that Mg（Zn,Cu,Al）2 in the second phase of Al2O3/7075 composites is dissolved gradually into the matrix with the increase of solution temperature and time. Compared with those of Al2O3/7075 composites, the microhardness, tensile strength and elongation of Al2O3/7075 composite with solution treatment at 460 ℃ for 5 h are increased by 37.2%, 19.0% and 46.2%, respectively.关键词：Al2O3/7075 Composites;Solid Solution Treatment;Microstructure;Mechanical Properties
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发布时间：2023-12-18 - 摘要：Strengthening of selective laser sintering coated sand by the heat treatment and infiltrating silica sol as well as sodium silicate was investigated comparatively. The characteristics and adaptability of three strengthening process were analyzed comparatively. The results show that the SLS coated sand presents the highest tensile strength of 2.78 MPa after heat treatment at 200 ℃ for 2 h, which is closed to that of one made by metal die molding, and can meet the casting requirements for conventaional castings. Infiltration of high-temperature resistant adhesive silica sol can increase slightly the room temperature strength of the coated sand, while it cann’t provide high temperature strength. Vacuum infiltration of sodium silicate can increase significantly the room temperature strength and high temperature strength of the coated sand. The room temperature strength reaches 6.87 MPa, and the residual strength is 0.86 MPa after treatment of holding for 2 h at 700 ℃. The infiltration of sodium silicate can be applied for hot mold casting of complex thin-wall castings. The infiltration depth can be controlled by adjusting vacuum degree and infiltration time to meet the requirement of different castings.关键词：Resin Coated Sand;SLS;Post-process
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发布时间：2023-12-18 - 摘要：AZ31 magnesium alloy was subjected to surface solid thermal diffusion treatment with La2O3 and pure Zn powder at 390 ℃ for 4 h, and the mass fraction of La2O3 in the diffusion agent is 0,0.2%, 0.4% and 0.6%, respectively. The evolution of the infiltrated layer microstructure of Mg alloy surface with adding different mass fractions La2O3 was analyzed. The hardness of the diffusion layer and the erosion corrosion wear performance in 3.5% NaCl solution and quartz sand were tested. The results show that without infiltration agent addition, the diffusion capacity of Zn atoms is insufficient and absence of infiltration layer can be observed. With 0.2% infiltration agent, the diffusion capacity of Zn atoms is enhanced, and different Mg-Zn compounds(Mg0.97Zn0.03+β-Mg17Al12+α-Mg+MgZn+Mg2Zn3+MgZn2) appear in the diffusion layer, where La2O3 plays the role as a catalyst during the diffusion process. With the increase of La2O3 in the infiltrant, when the content of La2O3 in the infiltrant exceeds 0.4%, the matrix of the AZ31 magnesium alloy disappears, and the number of phases in the layer is absent change. With increasing in La2O3, the microstructure is coarsened increasingly, and the change in structure results in changes in hardness and erosion corrosion performance. The hardness is increased with the increase of La2O3 in the osmotic agent, and the scouring corrosion wear performance presents desirable when the La2O3 content is 0.2%.关键词：AZ31 Magnesium Alloy;Solid Diffusion;La2O3;Zn;Hardness;Erosive-corrosive Wear
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发布时间：2023-12-18 - 摘要：Phase diagrams and solidification processes of Al-3 Si-0.4 Mg alloys with different Cr contents were calculated by the Thermo-Calc phase diagram software, which were verified by gravity casting. The results reveal that the experimental results are in good agreement with those calculated by Scheil module in Thermo-Calc software. When the contents of Cr is less then 0.13%, the effect of Cr on the microstructure of the alloy can be ignored. When the contents of Cr is more than 0.2%, Al13（Cr, Fe） 4Si4 phase can be observed. As the Cr content increased from 0.13% to 0.2%, the average length of the iron-rich phase in the alloy is decreased, and the volume fraction of the iron-rich phase in the alloy is increased.关键词：Al-Si-Mg Alloy;Cr;Microstructure;Phase Diagram
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发布时间：2023-12-18 - 摘要：The effects of lanthanum and neodymium on the microstructure and mechanical properties of A356 aluminum alloy were investigated by means of metallographic analysis and hardness testing with adding different content of lanthanum and Neodymium. The results reveal that the rare earth lanthanum and neodymium can refine the primary Al phase in A356 aluminum alloy, and decrease the secondary dendrite arm of the aluminum alloy and the coarse needle like eutectic silicon phase size. Secondary dendrite arm with La and Nd mixed addition can be decreased from 16.52 μm to 5.67 μm and 7.11 μm, respectively. The length of eutectic silicon is decreased from 7.5 μm to 1.24 μm and 2.06 μm, respectively. The tensile strength is increased significantly from 158 MPa to 218 MPa and 210 MPa, respectively.关键词：A356 Aluminium Alloy;Rare Earth Element;Modification;Tensile Property;Fracture Morphology
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发布时间：2023-12-18 - 摘要：The effects of different Zr content（0,0.1%,0.15%,0.2%,0.25%）on the microstructure and mechanical properties of Al-Zn-Mg-Cu alloy were investigated. The alloy with Zr content of 0.1% and 0.25% was treated by ultrasonic melt treatment before pouring, and the microstructure and mechanical properties after ultrasonic treatment were analyzed. The results reveal that Zr can refine grain size, however, with Zr content increase, composition segregation is deteriorated, and the secondary phase is increased in the grain, resulting in the increase of firstly and then decrease of as-cast tensile strength with decrease of elongation. After ultrasonic melt treatment, the grains are refined with uniform distribution and average size less than 50 μm, meanwhile, the second phase in the crystal disappears completely, and composition segregation is reduced significantly.关键词：Al-Zn-Mg-Cu Alloy;Zr;Ultrasonic Treatment;Squeeze Casting;Composition Segregation
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发布时间：2023-12-18 - 摘要：Porous Al-30 Zn alloy with high equivalent internal consumption value was prepared successfully by powder metallurgy step sintering method combined with NH4HCO3pore-making agent, and its microstructure, phase composition, hardness, damping performance and energy storage modulus were analyzed. The results reveal that the porosity of porous Al-Zn alloy can be effectively controlled by adding NH4HCO3 pore-forming agent, and a large closed pore structure can be formed without new phase formation. The hardness of porous Al-30 Zn alloy is decreased gradually with the increase of pore forming agent content. At 300 ℃ to 350 ℃, equivalent internal friction values of Al-30 Zn alloy with the 8% pore-forming agent addition are significantly higher than that of ones without pore-forming agent, and at 300 ℃, the equivalent internal friction of Al-30 Zn alloy with 8% pore-forming agent reaches up to 0.082, which is 54.7% higher than that of Al-30 Zn alloy without pore-forming agent. The energy storage modulus of porous Al-30 Zn alloy is decreased with the increase of temperature and the addition of pore-forming agent.关键词：Powder Sintered;Porous Al-30Zn Alloy;Microstructure;Damping Performance
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发布时间：2023-12-18 - 摘要：The effects of Al and Sn on the microstructure, corrosion and cutting performance of regenerated bismuth brass were investigated by adding different amounts of aluminum and tin in bismuth brass with the help of scanning electron microscope（SEM）, energy spectrum analyzer（EDS）, electrochemical corrosion, brass dezincification corrosion and drilling test. The results show that the corrosion resistance of bismuth brass is improved obviously by adding a small amount of Al, and the cutting performance of the material is weakened gradually with the increase of Al content. When Sn element is added alone, the corrosion performance of the material is increased with the increase of Sn content, while the cutting performance of recycled bismuth brass is decreased firstly and then increased. When the Sn content is 0.5%, the cutting behavior is the worst.关键词：Regenerated Bismuth Brass;Alloying;Corrosion Performance;Cutting Performance
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发布时间：2023-12-18 -
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