最新刊期
卷 37 ， 期 11 ， 2017
- 摘要：Cu-Ni-Nb alloy was fabricated by vacuum arc melting.The effects of Nb content on microstructure,melting point and thermal conductivity of Cu-Ni-Nb alloy were investigated.The results show that the Cu-Ni-Nb alloy is composed of Cu0.81 Ni0.19 matrix and the second phase of NbNi3.When the mass ratio of Ni/Nb is（610）∶1,the second phase morphology in the Cu-Ni-Nb alloy exhibits all lamellar structure.When the mass ratio of Ni/Nb is（24）∶1,the second phase morphology in Cu-Ni-Nb alloy presents the mixed structure of lamellar and particle structure.With the increase of Nb content,the solid solubility of nickel atoms in Cu-Ni-Nb alloy is decreased,so the melting point of the alloy is decreased,while the thermal conductivity is increased.The second phase in the Cu-20 Ni-5 Nb is fine lamellar and particle structure,which are distributed uniformly in the matrix.The second phase volume fraction reaches 19.2%,and the melting point of Cu-20 Ni-5 Nb alloy is 1 134.92℃ with its thermal conductivity up to 45.25 W/（m·K）,which can meet the requirements of manufacture and application of cast copper cooling water jacket.关键词：Cu-Ni-Nb Alloy;Microstructure;Melting Point;Thermal Conductivity
- 2
- |
- 100
- |
- 1
发布时间：2023-12-18 - 摘要：The effects of Sr addition on the microstructural evolution and mechanical properties of Mg-5.5 Zn-1.2 Y-0.6 Zr（ZWK611）alloys were investigated systematically using XRD,OM,FESEM,EDS and tensile tests.The results reveal that trace addition of Sr（0.08%）can refine grain size in the ZWK611 with the increase of second particles,so tensile strength and elongation of the alloy reach 246.1 MPa and14.5%,compared with those of alloy without Sr addition,increased by 10.1%and 21.8%,respectively.However,with further increasing in Sr addition,mechanical properties of the ZWK611 are decreased,which may be attributed to the combined effects of grain coarsening and decrease of the second phases strengthening as well as more W phases generation.关键词：Magnesium Alloy;Strontium;Microstructure;Mechanical Properties
- 2
- |
- 157
- |
- 0
发布时间：2023-12-18 - 摘要：In order to understand influence of preheating temperature on TiC/Ni functionally gradient coating,the TiC/Ni functionally gradient coating on H13 steel surface was prepared by self-propagating high temperature synthesis and pseudo hot isostatic pressing（SHS/PHIP）.The phase and microstructure of the coating were analyzed by XRD and SEM-EDS.Microhardness and bonding strength of the coating were tested by microhardness tester.The results reveal that the coating mainly consists of TiC particles generated in situ and Ni-based solid solution which closely wraps around the TiC particles.The coatings present porous skeleton structures.With the increase of preheating temperature,the coating surface porosities are decreased,while density,TiC grain size and surface hardness are increased.Meanwhile,element diffusion between coating and matrix is enhanced,and metallurgical bonding strength is increased.关键词：SHS/PHIP;TiC/Ni;Functionally Gradient Coating;Preheating Temperature
- 4
- |
- 57
- |
- 3
发布时间：2023-12-18 - 摘要：Mg-20 Cu-8 Sn and Mg-15 Ca-5 Sn alloys for magnesium based thermal storage materials were designed.Densities of two alloys were measured by drainage method.The microstructure,phase composition of the two alloys are characterized by metallographic microscope（OM）,X-ray diffraction（XRD）and electron microprobe（EPMA）.And thermal phase change temperature,latent heat were measured by differential scanning calorimetry（DSC）.The results show that the densities of Mg-20 Cu-8 Sn and Mg-15 Ca-5 Sn alloys reach 2.133 g/cm3 and 1.695 g/cm3,respectively.Mg-20 Cu-8 Sn alloy is composed ofα-Mg+CuMg2+Mg2 Sn and Mg-15 Ca-5 Sn consists ofα-Mg+MgCa2+Mg2 Sn.The phase transition temperature and latent heat of the two alloy are 462.42,517.37 ℃ and 136.4,195.1 J/g,respectively.关键词：Magnesium Alloy;Heat Storage Material;Thermal Properties
- 2
- |
- 95
- |
- 1
发布时间：2023-12-18 - 摘要：<正>自2015年11月伊之密HPM北美公司成功拍下位于美国俄亥俄州莫罗县（Morrow County）的一块土地及厂房以来,时隔两年,伊之密HPM北美新工厂于2017年10月份正式投入使用。伊之密HPM新工厂占地28 327平方米,其中厂房面积1 922平方米,办公面积约500平方米。新工厂将定位为HPM产品技术中心以及物料存储中心,将作为展厅向客户展示公司主要产品及先进成型工艺技术,必要时也为客户提供试模服务。与此同时,HPM旧厂房将作为为客户提供机器翻新维修服务的场所。
- 2
- |
- 13
- |
- 0
发布时间：2023-12-18 - 摘要：<正>据日经中文网报道,截至2017年11月6日,日本机器人制造商发那科FANUC的工业机器人累计产量已超过50万台。发那科1977年开始量产工业机器人,2015年11月实现累计生产40万台工业机器人,此后仅用两年产量就达到50万台。不仅在日本,亚洲各国在工厂节省人工、自动化方面的投资也在不断增长。因此发那科的机器人量产速度将进一步加快。目前,发那科每月生产超过6 000台工业机器人,但是该公司会长兼CEO稻叶善治表示,"生产已经达到顶峰,没法再增加产量了"。为进行增产,发那科正在日本茨城县筑西市建设每月最大产能达4 000台的大型工厂。今年5月初,发那科宣布投资630亿
- 2
- |
- 36
- |
- 0
发布时间：2023-12-18 - 摘要：<正>自1967年成立至今,技术和创新一直是高斯自动化在铸造元件领域的成功基石。高斯自动化（GAUSS）与客户进行了卓有成效的合作,合作随着时间的推移而不断发展与完善,并伴随着每套新装备的应用而得到进一步深化。在成功之路上,高斯自动化不断将先进的技术和创新引进客户业务中,并重点关注研发、产品质量、健康及安全和环50年的境。多年来,公司以全套工艺和设备为核心铝铸件生产提供和安装了众多越来越灵活高效的铸造元件。其中第一步是引进机器人喷出铸件,接下来便是萃取系统、操作人员安全设备和更高的生产灵活性。最近,公司开发了新的
- 2
- |
- 14
- |
- 0
发布时间：2023-12-18 - 摘要：<正>根据国外媒体报道,美国马里兰大学的一个华人科学家团队最近研制出了一种基于水基电解液的新型锂离子电池,该电池不仅在电压上首次达到了笔记本电脑等家用电子产品所需要的标准,同时还能避免着火和爆炸的危险。在现有的电子产品中,锂离子电池都使用了非水性电解液。电子设备在工作时电池电压必须要满足4V的标准,但在这个电压之下,水很容易就会被电解,所以锂电池通常所使用有机溶剂作为电解液,但这些电解液具有易燃易爆性,存在着极大的安全隐患。据了解,该研究团队曾经在2015年时就研发了一种水电解液电池,但由于电压最高只有3V,且电极性能会受到水溶液的影
- 2
- |
- 71
- |
- 0
发布时间：2023-12-18 - 摘要：The influence of w（Mg）/w（Si）mass ratio on the microstructure and mechanical properties of Al-4 Mg-xSi-0.6 Cr die casting alloys was investigated.The results reveal that Mg is mainly soluted inα-Al matrix and a small amount of Al3Mg2 particle phase can be generated,which results in the high comprehensive mechanical properties withoutSi added in the alloy.With the addition ofSi elements,the strength of the alloy is increased,while ductility is decreased sharply due to Mg andSi formed Al-Mg2Si eutectic microstructure.Al-Mg2Si eutectic lamellar spacing is increased and it’s morphology is transferred into concave polygon with the decrease of Mg/Si mass ratio,which can accelerate fracture during tensile process as a result of stress concentration.When the Mg/Si mass ratio is decrease to 1.6,with the increase ofSi,the amount of Mg2Si phase keeps constant value.Meanwhile,the strength is increased and ductility is decreased due to long stripSi eutectic phase formed in the die casting alloy.The category and morphology of Cr phase are related with Mg/Si mass ratio.With excess of Mg,the Cr exists in form of large block Al13 Cr2 phase,while with excessSi,the Cr is distributed evenly with irregular Al5（Cr,Fe）Si.关键词：Mg/Si Mass Ratio;Aluminum Die Casting Alloy;Mechanical Properties;Microstructure
- 2
- |
- 197
- |
- 4
发布时间：2023-12-18 - 摘要：Raveling magnetic field（TMF）was applied in the solidification of ZL205 Aalloy.The effects of different TMF current intensity on element distribution,microstructure and grain size of ZL205 Aalloy samples were investigated.The results show that distribution of Cu element is more uniform in the solidification of ZL205 Aalloy with TMF,and the grain size at the upper of the samples is refined.Due to the density difference,the deposited layer can be formed in the samples and thickness of the deposited layer is decreased with the increase of the intensity of excitation current and eventually disappear,which are attributed to the melt flow caused by TMF promoting the uniform distribution of solid phase and liquid phase.The element in the samples is more uniformly distribution and the deposition of the elements and phases can be avoided by TMF.关键词：Traveling Magnetic Field;ZL205A Alloy;Phase Deposition;Grain Size
- 2
- |
- 80
- |
- 1
发布时间：2023-12-18 - 摘要：The microstructure and phase structure of the Al-Si-Cu alloy prepared by the extrusion combined with N2 sintering were investigated by metallographic,SEM and XRD,and mechanical properties of the alloy were measured.The results show that after extrusion,the relative density of the alloy is increased as a result of the decrease of gas hole,and the grains of the Al and Cu are distributed homogenously in the Al matrix with absence of obvious interface.The phase structure is composed ofα-Al,β-Si,Al2 O3,CuAl2 and Cu4 Si,in which the CuAl2 and Cu4 Si are generated during the extrusion following the sintering.The mechanical properties of the alloy prepared are increased obviously,where the hardness,tensile strength and elongation reach 71.5 HV,400 MPa and 13.8%,respectively.The fracture morphology of the alloy prepared is changed from typical brittle fracture of rock candy to ductility fracture containing dimples.关键词：Powder Metallurgy;Al-Si-Cu Alloy;Extrusion;Microstructure;Mechanical Properties
- 2
- |
- 100
- |
- 0
发布时间：2023-12-18 - 摘要：In order to reduce or eliminate residual stress and improve dimensional accuracy and stability of aluminum alloy thin-walled cylindrical parts,the compression plastic mini-deformation process exerted on the blank made by hot extrusion process was adopted.The process experimental results show that when the deformation rate exerted on the blank is more than 1%,the dimesional accuracy of aluminum alloy thin-walled cylindrical parts can be improved significantly,while the deformation rate exerted on the blank is more than 2%,the roundness tolerance variation of aluminum alloy thin-walled cylindrical parts can tend to be stable.The compression plastic mini-deformation process is one of both effective and convenient process for improving dimensional accuracy and stability of aluminum alloy thin-walled cylindrical parts in actual production.关键词：Aluminum Alloy;Dimensional Stability;Residual Stress;Thin-walled Part
- 2
- |
- 95
- |
- 2
发布时间：2023-12-18 - 摘要：<正>近日,包头稀土研究院中试基地稀土镁合金中试线完成镁合金半连续熔铸系统的调试生产,制备出300mm×4000 mm的镁合金棒材。对其机械加工后进行的超声无损检测显示,合金铸棒无铸造缺陷,符合对应产品质量要求,下一步将进行大尺寸稀土镁合金棒材的产业化制备工艺开发。镁合金半连续铸造技术是将镁合金液经过结晶器凝结成壳后从下方拉出喷水冷却成具有一定断面形状和一定长度的铸坯的过程。半连续铸造生产的锭坯具有晶粒细小、
- 2
- |
- 45
- |
- 0
发布时间：2023-12-18 - 摘要：<正>近日,国产大型客机C919再获130架订单,总订单累计达730架。随着中国大飞机订单的不断增加,也为下游供应商带来更多机会。德国老牌铝企乌纳铝业行政总裁Thomas Wiese日前透露,公司产品已经获得中国商用飞机有限责任公司（中国商飞）认证,未来有望接获中国大飞机的订单。资料显示,乌纳铝业是德国高端铝挤压企业,其产品主要是供世界顶尖飞机制造商使用的高端铝挤压无缝管等。值得注意的是,这家企业最近刚刚被中国忠旺收购。在业内人士看来,拿下乌纳铝业,为中国忠旺的海外战略打开了好的局面,也为其拓展航空用铝领域奠定了基础。根据中国航空工业第一集团公司预测,到2025年国内运输飞机拥有量将达3 900架,其中大型客机将达2 000架,这将使中国成为仅次于美国的全球第二大航空市场。
- 2
- |
- 49
- |
- 0
发布时间：2023-12-18 - 摘要：<正>2017年11月3日,吉利集团建设的吉利新能源汽车产业化项目开工推进动员大会在西安经开区召开。据了解,吉利新能源汽车产业化项目落户西安经开区泾渭新城,该项目于2017年7月18日签约西安,计划年底前开工。这次开工提前了2个月时间,并且在原有投资基础上追加了84.6亿元,总投资达到201.6亿元。将建设包括新能源汽车整车制造、零部件生产、物流配套,冲压、焊装、涂装、总装四大工艺厂房,以及配套管理中心、生活配套区等在内的各项辅助设施。
- 2
- |
- 120
- |
- 0
发布时间：2023-12-18 - 摘要：<正>2017年10月24日,来自布勒压铸中国的主要客户以及行业媒体欢聚一堂,共同庆祝布勒中国压铸技术中心开幕。布勒压铸应用技术中心是布勒公司成立的集试模、培训及应用技术研发于一身的部门,分布在瑞士、中国、印度、荷兰和美国。此次布勒中国压铸技术中心配备了Carat140和Ecoline S Pro 53两台压铸机,集成BuhlRob,KU-KA机器人,WOLLIN喷涂系统,莱格禄普模温机,KMA除尘系统,布勒集成给汤机和SmartVac抽真空系统等设
- 2
- |
- 19
- |
- 0
发布时间：2023-12-18 - 摘要：<正>国内首座汽车零部件行业"整车环境风洞试验室"在天津三电汽车空调有限公司落成并正式投入使用。这座总建筑面积4100平方米的"整车环境风洞试验室"是目前国内功能最全、技术最先进的整车环境风洞试验室。它秉承"开放、共享"方式,将为整车及汽车零部件制造企业提供更有力的研发基础、更可靠的数据依托以及更宝贵的学习和探讨技术平台。2015年初,天津三电汽车空调有限公司斥资逾亿元人民币,正式启动"汽车环境风洞试验室"建设项目。来自中国、德国、美国、加拿大、韩国、瑞典等一批国内外知名企业参与试验室设备供应,联手打造中国汽车零部件行业第一座整车环境风洞试验室。
- 2
- |
- 29
- |
- 0
发布时间：2023-12-18 -
- 摘要：<正>针对不同工程应用的目标需求,国家金属腐蚀控制研究中心发明了系列镁合金表面处理技术,并取得了广泛应用。发明的钝化效果好的环保型化学转化膜技术,具有成本低、结合力强、耐腐蚀性佳等特点,被美国独立第三方盲评为国际领先技术,已经成功在汽车部件上批量应用（已装车数百万辆）。化学转化膜技术在中国和美国均已经获授权发明专利。
- 2
- |
- 154
- |
- 1
发布时间：2023-12-18 - 摘要：To realize requirements of " improving quality and efficiency" in the casting enterprises,through deeply analyzing production-management status of some casting plants,process optimization and consolidation Eraser-SDCA method was proposed.In the process,Eraser method was used to optimize the existing production process,and SDCA recycling method was used to consolidate the optimized new process to assure the optimization effects.The methods were applied in the practical production.The results verify that the method not only improves effectively the production efficiency of the casting plant but also strengthens the quality control.关键词：Eraser-SDCA;Casting;Production Management;Quality Control;Process Optimization
- 2
- |
- 131
- |
- 8
发布时间：2023-12-18 - 摘要：Through using cold crucible to curing nuclear waste and deeply burying solidified body,the detriment of nuclear waste for environment could be prevented.The temperature distribution of melt interior will impact the quality of the solidified body directly.A temperature field calculation model was established by Ansys software.Then accuracy of the model was verified by experiments.The distribution of temperature field in melt was simulated and the distribution of temperature was analyzed at different power parameters by using the model.The results reveal that with the increase of current value and frequency,heating time to the operating temperature can be shortened,however,the temperature gradient can be enlarged,which cause the uneven distribution in melt.Smelting process should set mechanical agitation on the basis of physical conditions.关键词：Cold Crucible;Glass Solidification;Temperature Field;Numerical Simulation
- 2
- |
- 99
- |
- 2
发布时间：2023-12-18 - 摘要：Numerical simulation of backward extrusion AZ80 magnesium alloy thick-walled pipe was carried out by using Deform-3 Dsoftware.The influence of extrusion temperature and extrusion speed on the forming process of backward extrusion was simulated and analyzed.The results reveal that the equivalent strain of the reverse extrusion process is mainly concentrated on the contact position between the punch and blank as well as on the pipe wall.The damage value of the inner wall and the outer wall of the pipe exhibits serious,and it is easy to cause damage.With increasing in the extrusion temperature,the temperature difference,equivalent stress and extrusion load of the tube forming are decreased,so the extrusion deformation is more uniform.With decreasing in the extrusion speed,the peak value of the metal flow rate is decreased,and the metal flow is more uniform with the decrease of the tube temperature difference,so the extrusion deformation presents more unifrom.The reliability of the simulated results is verified by the backward extrusion test of the magnesium alloy tube.关键词：Numerical Simulation;AZ80 Magnesium Alloy;Backward Extrusion;Thick Walled Pipe
- 2
- |
- 205
- |
- 2
发布时间：2023-12-18 - 摘要：Magnetic field measurement in semi-solid slurry electromagnetic stirrer by three-dimensional digital magnetic measurement method was carried out.The experimental results show that the magnetic induction in the electromagnetic stirrer is approximately 100 mT,and the magnetic induction is uniformly distributed along the axial and radial electromagnetic stirrer.The magnetic induction distribution exhibits the apparent changes with different combination of electromagnetic stirring voltage and frequency.关键词：Electromagnetic Stirring;Magnetic Field Measurement;Magnetic Induction
- 2
- |
- 66
- |
- 1
发布时间：2023-12-18 - 摘要：The semi-solid alloy slurry of Al-7 Si alloy was prepared by the internal cooling type mixing stirring method.The effects of different melt stirring initial temperature,ratio of internal cooling mixing block,stirring rate and sampling temperature on semi-solid microstructure and average grain size as well as the shape factor of the primaryα-Al in the Al-7 Si alloy were investigated.The mechanism of forming fine near-spheroids by internal cooling mixing methods was described.The results reveal that with the melt stirring initial temperature of 625℃,and ratio of mixing block of 5%,the stirring rate of 1 200 r/min and the sample temperature of 600 ℃,the semi-solid slurry with near-spherodized primaryα-Al can be obtained,where the average grain size and the shape factor reach 64.21μm and 0.649 0,respectively.关键词：Semi-solid Microstructure;Al-7Si Alloy;Internal Cooling Type Mixing Method;Primary α-Al
- 2
- |
- 156
- |
- 4
发布时间：2023-12-18 - 摘要：Aiming at high defects and low yield rate in low-pressure casting totally enclosed electrical aluminium alloy combination tanks,through the ProCAST software for simulating the original casting process as well as the comparative testing,and combining the practical production,the optimized parameters were determined.Through modifying the shape and adjusting gating system,the casting defects were eliminated.The results reveal that with pouring temperature of 700℃,the filling pressure of54 kPa and mould temperature of 300℃,through increasing the casting lower wall thickness by 1.5 mm to obtain rational thickness gradient,as well as enlarging original casting sprue width from 12.5 mm to19.5 mm,the casting defects can be relieved greatly,improving the quality of castings.关键词：Aluminum Alloy Tanks;Low Pressure Casting;Numerical Simulation
- 2
- |
- 83
- |
- 2
发布时间：2023-12-18 - 摘要：The existing problems of heat insulating die coating for low-pressure casting aluminum alloy wheels were analyzed in order to improve the adhesion force of the coating.During the low-pressure casting process,because of its unreasonable composition and single structure,the existing die heat insulating coating is easily dropped off block or being scoured and worn thin,and even it takes metal die be exposed to the air and aluminum liquid.Improvement methods for the existing insulating die coating was presenetd on the basis of comprehensive analysis of its composition.By means of improving the composition and introducing potassium titanate whisker and combining suitable spray ways,casting production efficiency was promoted effectively,and yield product rate was improved and production cost was reduced.关键词：Low-pressure Casting;Aluminum Alloy Wheels;Heat Insulating Coating;Adhesion Force
- 2
- |
- 143
- |
- 3
发布时间：2023-12-18 - 摘要：Bauxite and talcum powder was adopted as the refractory aggregate to prepare EPC coating for magnesium alloy.Through measuring coating performance,effects of suspending agent and binder addition on the properties of EPC coating were analyzed.The results reveal that the coating prepared with bauxite（90%）,talc aggregate（10%）,sodium bentonite 6%,CMC 0.8%,PVA 1.5% and silica sol binder 10%,has the desirable strength,viscosity and suspension properties,presenting excellent properties as magnesium EPC coating.By practical pouring,Mg alloy castings with high quality and smooth surface were produced sucessfully.关键词：EPC;Magnesium Alloy;Bauxite Coating
- 2
- |
- 150
- |
- 3
发布时间：2023-12-18 - 摘要：Effects of SiC particle content on microstructure and properties of lost foam casting SiC particle reinforced aluminum matrix composites were investigated.The result reveal that microstructure of the composites prepared is independent on the SiC particle content and size.In addition,the bonding strength between matrix and the SiC particle is independent of the particle size.With SiC content increase,the bending strength of the composites with the same particle size is decreased,while at the same SiC particle content,with increasing in particle size,the bending strength of the composites exhibits increased firstly and then decreased.The composites with 46 mesh SiC content have the higher bending strength.关键词：Lost Foam Casting;SiC Particle;Aluminum Matrix Composites;Concentration;Particle Size
- 2
- |
- 77
- |
- 1
发布时间：2023-12-18 - 摘要：CoCrFeMnNiCux high entropy alloys were prepared by vacuum arc furnace,and effects of Cu content on its microstructure and mechanical properties were investigated.The results show that microstructure of the alloys exhibits the dendrites.The dendrites in all alloys are slightly enriched in Co,Cr,Fe,and the interdendritic is slightly enriched in Mn,Ni,while the Cu is segregated easily at interdendritic.The alloys still form a simple FCC solid solution after Cu addition.With the increase of Cu content,the compressive strength and microhardness of the alloys are increased firstly and then decreased,however,the change amplitude is very small.CoCrFeMnNiCux alloy exhibits the highest compressive strength and microhardness when Cu content is 0.8.The compressive strength and microhardness of the six component high entropy alloy containing Cu are the higher than those of the five component high entropy alloy without Cu.关键词：High Entropy Alloy;Microstructure;Mechanical Properties
- 2
- |
- 286
- |
- 2
发布时间：2023-12-18 - 摘要：A new mode of rapid sand casting based on 3D technology was presented,which could realize the 3 Ddesign,production and detection of whole casting process.Compared with those of conventional casting modes,the new mode can shorten effectively the production time and improve the dimension presicion and internal quality of the components.The mode can be applied for the production of single part and small production-volume production.关键词：3D Technology;Rapid Casting;Sand Casting;New Mode
- 2
- |
- 246
- |
- 2
发布时间：2023-12-18 - 摘要：Different casting parameters were simulated by the ProCAST software in order to solve the hot tearing of circular plate castings of K403 nickel-based superalloy during solidification process.The simulation results were compared with the practical casting process.The analysis results show that the time of the stress generated from the juncture of top riser and casting reaches 2.7 hwith top riser and the divided parts,while the time of stress generation is more than 5 hwith the integral top riser.The maximum tensile stress of the juncture of top riser with four divided parts and casting reaches 12 MPa only,which is 20%30% of that with the integral top riser,decreasing greatly tendency of hot tearing.In the practical process of casting,castings with four parts of top riser and lower pouring temperature are beneficial to reduce the hot tearing susceptibility of casting,which is accordant with the simulated ones.关键词：Casting Parameters;Castings;Numerical Simulation;Hot Tearing
- 2
- |
- 70
- |
- 0
发布时间：2023-12-18 - 摘要：SiC particles were stirred and pickled by 10% hydrofluoric acid,and SiC particle reinforced6061 Al matrix composites were prepared by direct electrothermal thixotropic forming.The effects of SiC pickling treatment on the microstructure and mechanical properties of the composites were investigated.The results reveal that interface of the enhanced particles pickled by 10% hydrofluoric acid exhibits straight and clean with occurrence of erosion pit,and the specific surface area of the SiC particles is increased.Meanwhile,the interface of SiC particles with the aluminum matrix exhibits the desirable bonding,and the voids are reduced with absence of impurity phases.The porosity is reduced,and the compactness and the flexural strength are improve remarkably compared with those of the composite which is not subjected to the surface treatment.关键词：Pretreatment;Acid Washing;Composites;SiC;Direct Electrothermal Method
- 2
- |
- 76
- |
- 3
发布时间：2023-12-18 - 摘要：Influence of varied rare earth Er content on microstructure and properties of the in situ Mg2Si/AZ91 composites was investigated,and its modification mechanism was described.The results reveal that the proper amount of Er can refine effectively the matrix grain size and change the size,morphology and distribution of the reinforcing particles Mg2Si phase in the matrix.With 0.5% Er addition,matrix grain size is refined from 250μm to 180μm,and primary Mg2Si phase is transformed from coarse Chinese script into short rod structure with decrease of size from 50μm to 20μm.Meanwhile,the tensile strength and elongation of the alloy are increased from 168 MPa and 1.8% to 190 MPa and 2.7%,respectively.关键词：Modification;In-situ;Mg2Si/AZ91 Composites;Er
- 2
- |
- 65
- |
- 1
发布时间：2023-12-18 - 摘要：SiCp/Al-8.5 Fe-1.3 V-1.7 Si composites prepared by multi-layer spraying deposition were densified by multi-pass wedge pressing.Equipment,forming principle and procedure of wedge pressing of spraying deposited Al-matrix composite were introduced.Evolution of pore,SiCpdistribution,secondphase dispersoids and SiC/Al interface of composite plate during wedge pressing were observed.The results reveal that the composite blank can be densified by wedge pressing,and boundaries at deposited particles are eliminated by wedge pressing with 50% in reduction,and relative density of the pressed composites reaches up to 97.6% with homogeneous SiC particle distribution.However,the dispersed pores are difficult to be eliminated by wedge pressing because of its low shearing forces.Dispersoids still keep with 60100 nm in diameter from growing obviously and transforming into equilibrium phase such as Al13 Fe4 during the wedge pressing at 480℃.SiC/Al interface of the composite plate as-wedge pressed exhibits clean,which is contributed to the wettability between SiCpand Al matrix.关键词：Spraying Deposition;Heat Resistant Alloy;Composites;Wedge Pressing;Microstructure Evolution
- 2
- |
- 63
- |
- 2
发布时间：2023-12-18 - 摘要：The three-dimensional micrograph was managed to a binarization image,and then the agglomeration area of binarization image was treated as the multiple particles,and the single particle was regarded as a mass point.All these disposing process of EPS/CBN composite foam pattern will use to obtain a distribution of the points that can accurately characterize the CBN abrasive distribution of composite foam sample.Furthermore,the distribution of the points was constructed as a Tyson polygon.Applying Tyson polygon area statistical analysis,the uniformity of abrasive distribution in the composite foam sample was evaluated quantitatively.Finally,the method was used to evaluate the surface abrasive distribution uniformity of different EPS/CBN composite foam pattern that generated at different process.The results reveal that the obtained parameters can be used effectively to evaluate uniformity of abrasive distribution configuration with abrasive agglomeration.关键词：CBN Abrasive;Distribution Uniformity;Tyson Polygon;Statistical Analysis
- 2
- |
- 82
- |
- 2
发布时间：2023-12-18 - 摘要：In order to improve the grain refinement effect of Mg-Al alloys in aerospace industry,the calculation and analysis of Gibbs free energies of the metallurgical chemical reactions were carried out.The analysis results indicate that the de-composition reaction of MgCO3 in Mg-Al alloys melt is hard to be controlled,which influences the refinement effect on Mg-Al alloys.Then gaseous CO2 is thought to be the equal or even much better efficiency on the grain refinement of AM60 Balloy than MgCO3.MgCO3 was added into AM60 Balloy melt,as well gaseous CO2 with the same carbon content.The experiment results indicate that the average grain size of AM60 Balloy is decreased from 213μm to 113μm,while the microhardness is increased by 11.48% with the addition of MgCO3,and the average grain size of AM60 Balloy is decreased to 91μm while the microhardness is increased by 8.32% with addition of CO2 at equal carbon content.Based on SEM,EDS and XRD analysis,the refinement mechanism of MgCO3 is the same as that of gaseous CO2,that is,Al4 C3 generated by reaction of Al and C served as the heterogeneous nucleation substrates,which takes about the grain refinement of AM60 Balloy.关键词：AM60B Alloy;Thermo-dynamic Analysis;Grain Refinement;MgCO3;Gaseous CO2
- 2
- |
- 43
- |
- 0
发布时间：2023-12-18 - 摘要：The variation of grain size and solidification cooling curve of 7 A04 aluminum alloy in the rectangular magnetic field was analyzed.The distribution of magnetic induction intensity,electromagnetic force and magnetic energy in the melt were analyzed by finite element method.Effect of the rectangular wave magnetic field on the grain refinement was expounded.The results reveal that the solidification structure of 7 A04 aluminum alloy can be refined to some extent by the rectangular wave magnetic field.With the optimized processing parameters,such as frequency of 20 Hz,peak current of 100 Aand current duty cycle of 20%,the average grain size in the ingot at the center and 1/2 radius as well as surface reach 122.9μm,120.4μm,114.7μm,respectively,which are decreased by 24.3%,15.3%,22.6%,respectively,compared with those of un-treated ones.In addition,the maximum density of electromagnetic force is 7.01×104 N/m3,and the magnetic energy density reaches 3 862.62 J/m3,forming agood solidification structure refinement conditions.关键词：Rectangular Wave Magnetic Field;Grain Refinement;Electromagnetic Force;Magnetic Energy;Current Duty Ratio
- 2
- |
- 106
- |
- 5
发布时间：2023-12-18 - 摘要：The reaction between salt fluxes containing metal fluorides and main elements in A356 alloy was investigated by thermodynamics analysis and experiments,and its influence on microstructure and constituent of Al alloy and the phase of fluxes were analyzed by SEM,EDS and XRD.The results reveal that the equilibrium constants of displacement reactions between main elements of A356 alloy and metal chlorides are mostly lower than those of metal fluorides,which indicate that metal chlorides are more stable than fluorides in salt fluxes.NaF,SrF2 and BaF2 in the fluxes can react easily with Al or Mg and generate the divorced atoms in Al melt,such as Na,Sr,Ba,to modify eutectic silicon significantly.Na3 AlF6 fluxes can also react with Al and generate trace the divorced Na atoms to modify eutectic silicon slightly.However,influences of AlF3,MgF2 and CaF2 on microstructures of A356 alloy can be ignored.Metal fluorides not exhibit measurable effects on the phase of salt fluxes while NaF and BaF2 can generate new phases KMgF3 and BaFCl in salt fluxes,respectively.MgF2,CaF2,SrF2,BaF2 would remain in A356 alloy because of their high densities and melting points,which could affect the constituents of alloy.关键词：Salt Flux;Metal Fluoride;A356 Alloy;Thermodynamics;Microstructure
- 2
- |
- 84
- |
- 1
发布时间：2023-12-18 - 摘要：Combining with alloying and cast-rolling method,rare earth elements La and Ce were added into AZ series magnesium to fabricate magnesium sheet with high tensile strength and low cost.The microstructure of the Mg alloy sheet was observed by OM and SEM.The results reveal that fine rare earth phases are distributed uniformly in the matrix,and tensile strength can reach 376 MPa.And then,compared with the cast-rolling sheet with cast magnesium alloy produced by slow cooling,the results show that rapid cooling exhibits the higher refined grain effect.关键词：Rare Earth Magnesium Alloy;La/Ce Alloying;Cast-rolling
- 2
- |
- 100
- |
- 1
发布时间：2023-12-18 - 摘要：The change of microstructure and hardness of the TA2 alloy was analyzed after heat treatment at 600,700,800 and 910 ℃for 2 h.Microstructural observation of TA2 was carried out at air cooling,water cooling and furnace cooling.The results reveal that with increasing in holding temperature,grain size in the alloy is increased.Compared with the air cooling and water cooling,furnace cooling presents the more effects of coarsening grain size.Hardness testing shows that TA2 alloy with different thickness exhibits the maximum value at 910 ℃for 2 hafter water cooling.关键词：Heat Treatment;TA2 Alloy;Microstructure;Hardness
- 2
- |
- 238
- |
- 2
发布时间：2023-12-18 - 摘要：In order to explore effects of power ultrasound on micro-defects in large size 2219 aluminum alloy ingot with a diameter of 1 250 mm,the specimens after being polished were analyzed by scanning electron microscopy（SEM）,energy spectrum analysis and optical microscopic analysis.The results show that the content of oxide inclusion in ultrasonic ingot is decreased significantly by 21%.The average size of defects is decreased from 10.606μm to 8.096μm by 23.7%.However,the number of micro defects in ultrasonic ingot is increased from 2 452 to 3 786,which proves that power ultrasound can restrain effectively the emergence of large size micro defects in large size aluminum alloy ingot.关键词：Power Ultrasonic;Oxide Inclusions;Micro-Defects;Grain Refinement
- 2
- |
- 123
- |
- 2
发布时间：2023-12-18 - 摘要：The porous copper with regular pore distribution was prepared by directional solidification with different withdrawal speed at 0.55 mm/s,0.7 mm/s and 1 mm/s,respectively.The non-destructive nano CT scanning technique was applied to analyze porous copper structure and make three-dimensional reconstruction.Influences of the withdrawal speed on the number of pore nucleus,porosity and pore size and distribution were investigated.The results reveal that,with the solidification,the number of pore nuclei is decreased gradually and tends to be stable,and the nucleation phenomenon of the new pore is present in the whole orientation solidification process.When the speed is increased,the number of new pores in the ingot is increased with the decrease of the average diameter of the pores and the uniformity of the pore size distribution.关键词：Directional Solidification;Lotus-type Porous Copper;Three-Dimensional Reconstruction
- 2
- |
- 116
- |
- 0
发布时间：2023-12-18
- Technical support is provided by Beijing Founder electronics co., LTD 京ICP备09064830号-19
京公网安备11010802024621 - It is recommended to read the content of this site in Chrome&IE9+. Please switch to extreme mode in browser 360.
- Cookies We use cookies to help provide and enhance our service and tailor content. By continuing, you agree to the use of cookies.
0