铝合金压铸模CAD系统中参数化设计的研究

利用VisualFoxpro语言建立数据库 ,对铝合金压铸模中各模板及零件进行编程设计。设计运行结果生成.dbf数据文件存放在数据输出库中。采用C语言编程 ,将数据文件转化成在AutoCAD下可执行的.SCR文件 ,使用SCRIPT命令 ,便会在AutoCAD绘图方式下自动生成所需的模具设计图形文件 ,从而实现压铸模CAD系统的参数化设计     

国外弧焊传感器的现状

概述了国外弧焊传感器的发展现状，并介绍了一些应用实例。     

Numerical simulation and experimental study on cavity growth in uniaxial tension of superplastic magnesium alloy

1　INTRODUCTIONMagnesiumisthelightestmetalinallconven tionalcommercialstructuralalloys .Itshighspecificstrengthandrigidity ,gooddampingcapacitiesareat tractiveforvariousstructuralapplications[14 ] .Be causeofitshexagonalclosepacked (HCP )crystalstructurewithalimitednumberofoperativeslipsys temsatroomtemperature ,magnesiumalloysaremuchmoreworkableatelevatedtemperaturesasaddi tionalslipsystemsareavailable[57] .Applicationsofthesuperplasticformingtechnologyofmagnesiumal loyshaverecentlyattr…     

镁合金AZ31轧制板材的单向拉伸行为

通过单向拉伸试验研究了AZ31镁合金轧制板在不同温度和应变速率下的力学性能。根据镁合金在50℃~400℃范围内的单向拉伸曲线分析结果,找出AZ31镁合金的抗拉强度、伸长率随变形温度、变形速度的变化规律。结果表明:AZ31镁合金轧制板的塑性随着应变速率的降低有明显提高;温度的升高可明显改善轧制板的塑性;当应变速率为1.5×10-2s-1、温度为400℃时,伸长率达到123.9%。     

AZ91D镁合金壳形件真空压铸充型和凝固过程的数值模拟

运用有限元模拟仿真软件对镁合金AZ91D壳形件进行多组正交试验真空压铸过程的数值模拟,找出最佳的压铸工艺参数.通过模拟结果表明:最佳压铸工艺参数为浇注温度655℃、冲头压射速度3 m/s、模具初始温度200℃.在这组优化的工艺参数下,通过对液态合金充型及凝固过程的可视化观察,有效的预测铸造缺陷产生的部位及原因,从而在实际生产中采取相应的措施避免缺陷的产生,优化铸造过程.     

镁合金AZ91D压铸的数值模拟

运用有限元模拟软件对镁合金AZ91D零件在普通压铸与真空压铸下进行计算机数值模拟,有效的预测液态金属在充型过程、凝固过程中的流场、温度场及宏观缺陷,以此对宏观缺陷的出现进行控制,优化铸造过程。此外比较真空压铸与普通压铸对铸件气孔率的影响。结果表明,当铸造工艺参数分别为冲头压射速度2.4 m/s、浇注温度655℃、模具初始温度180℃时,与压铸相比,真空压铸能有效减少铸件的气孔率,改善铸件质量。     

混合气体配比对焊接飞溅率的影响

气体保护焊方法由于其效率高,焊缝质量好等优点,获得了广泛的应用.其中CO_2焊与熔化极氩弧焊,都具有明弧、无渣、焊接质量好,焊接生产率高以及能进行全位置焊接等特点,但CO_2焊的成本比氩弧焊低,不足之处是飞溅大,焊缝氧化层厚;而熔化极氩弧焊也存在电弧飘和成本高的问题.使用Ar和CO_2混合气体保护,既减轻了CO_2的氧化性,又使电弧燃烧更稳定,减小飞溅,降低成本.本文通过试验,分析混合气体的混合比(Ar/CO_2)对飞溅率的影响,为工厂根据不同产品要求选择     

Superplasticity and diffusion bonding of magnesium alloy ZK60

1 INTRODUCTIONRecently , the use of magnesium alloys asstructural materials has significantlyincreased,forits good damping capacity , di mension stability ,machinability and lowcasting costs . But magnesi-umalloys normally exhibit lowductility near roomtemperature because of their HCP structure .Therefore ,it is necessary to i mprove the ductilityof these alloys for their use as structural compo-nents[1 3].In manufacturing,superplastic forming is of-ten combined with diffusion bonding, w…     

Property and microstructure analysis of ZK60 alloy superplastic sheet

It was investigated that the superplastic mechanical properties of fine-grained ZK60 magnesium alloy sheets at the temperature range of 200-420 ℃ and strain rate range of 5.56 × 10-4 -5.56 ×10-2 s-1 by tensile tests.And the microstructure evolution during the superplastic deformation of ZK60 magnesium alloy was examined by metallurgical microscope and transmission electronic microscope (TEM).The results showed that fine-grained ZK60 magnesium alloy starts to exhibit superplasticity from 250 ℃ and the maximum elongation is about 1106% at 400 ℃ and 5.56 × 10-4 s-1.The strain rate sensitivity is significantly enhanced with the increase of temperature and with the decrease of strain rate.The predominate superplastic mechanism of ZK60 magnesium alloy is grain boundary slide (GBS) at the temperature range of 300-400 ℃.The grains of ZK60 alloy remain equaxial after superplastic deformation,and dynamic continuous recrystallization (DCRX) is an important softening mechanism and grain stability mechanism during the superplastic deformation of the alloy.The curved grain boundaries and crumpled bands at grain boundaries after deformation prove GBS generates during superplastic deformation of ZK60 magnesium alloy.     

亚微米活化Mo-15Cu合金晶间反应机制（英文）

为了研究具有亚微米组分的钼铜粉末烧结时的晶间反应机制,采用亚微米活化层法制备了一种具备晶间反应层的钼铜复合材料。采用X射线衍射仪(XRD)、扫描电镜(SEM)、能谱仪(EDS)、透射电镜(TEM)、高分辨透射电镜(HRTEM),对Mo-15Cu合金组织形貌、连接和结构特征进行了表征。研究了亚微米活化层对钼铜复合材料晶间反应的影响。结果表明,添加8%(质量分数)亚微米粉,可形成厚度约0.5μm纳米活化层。Mo亚微米颗粒通过流动、扩散,改变晶间反应机制,形成了真正意义上的晶间反应层,厚度约为5 nm,实现了冶金结合。