铝合金泵盖压铸件气孔缺陷分析及对策

分析指出铝合金熔炼时加强炉料的管理和精炼除气以及压铸时采用合理的压射速度，可以有效地减少气孔缺陷的产生。结合铝合金铸件的实际生产情况，提出采用合理的压室容积比，减少压射时金属液中卷入的气体，可以减少压铸件的气孔缺陷。     

压铸件气孔缺陷分析及解决方案

从检查压铸件缺陷入手,根据气孔特征,确定出气孔的种类.讨论了各种气孔的形成机理,借助计算机模拟分析和相应的现场过程调查分析,找出了形成气孔原因.提出了解决各种气孔缺陷的相应办法,减轻或预防了气孔缺陷发生.     

铝合金挤压铸件气孔缺陷的分析

本文对造成高压锅渗漏报废的气孔缺陷,用扫描电镜和电子探针等手段,结合铝合金挤压铸造生产特点和现场生产情况,对其形成机理进行了探讨和分析;所得结果可供现场参考。     

压铸铝合金及先进的压铸技术

综述了压铸铝合金的性能、优点汽车工业中的应用情况,简要介绍了合金元素在压铸铝合金中的作用以及世界各国所使用的压铸铝合金材料及其工艺。     

锌合金压铸件气孔缺陷的分析与解决

Zn合金压铸件气孔缺陷产生的原因有操作者、机器、工艺、材料和环境,因果分析法可以逐个分解出中原因和小原因.一般情况下,铸件结构、模具设计、温度控制、速度控制、时间控制、压力控制和涂料等中原因是气孔产生的主要原因.实例表明,因果分析法可以找出气孔缺陷产生的主要原因,并可进一步加以解决,同时,它是一个具有通用性的行之有效的方法.     

消除铝合金压铸件气孔缺陷的工艺改进

针对铝合金压铸件气孔属于内部缺陷且不容易被观察和识别,尤其是密集针孔型气孔缺陷,X光探伤也不能识别检测出来的情况,在压铸成型金属填充理论的基础上对其形成进行分析和控制;通过双通道高真空技术、净化除气技术、喷涂工艺优化、浇注溢流系统优化、压铸工艺参数调整等技术的研究与应用来解决压铸件气孔缺陷;经过批量生产后,证明这些改善技术效果显著。     

铝合金压铸零件的质量缺陷及改善措施

介绍了压铸生产中铸件常见的质量缺陷、产生原因和主要影响因素,结合实例对铝合金缸体压铸过程中出现的气孔、缩孔、裂纹、欠铸等典型质量缺陷进行了分析,找出了影响压铸铝合金缸体质量的关键缺陷和缺陷发生的主要部位,针对不同的部位和缺陷,提出了解决这些质量问题的思路、对策和消除缺陷的具体措施。     

压铸件常见缺陷及分析

对铝合金压铸生产中存在的一些缺陷进行分类剖析,阐述了产生这些缺陷的原因,从而为进一步改善铸件质量提供了一定的依据。     

压铸铝合金及压铸技术的研究进展

综述了压铸铝合金的开发及应用状况、计算机模拟技术在压铸铝压铸技术中的应用、半固态流变压铸浆料制备及超低速压铸技术等先进铝合金压铸技术研究的最新进展.并指出将不同先进压铸技术的结合应用,可进一步提高铝合金压铸件性能,促进压铸技术的发展.     

压铸铝合金离合器壳体的泄漏缺陷分析与对策

以某汽车压铸铝合金离合器壳体出现的泄漏缺陷为研究对象,分析了铸件发生泄漏的原因。通过优化压铸工艺参数、减小泄漏部位的壁厚及加工余量、增加模具凸台的高压冷却等措施,消除了泄漏部位的内部缩孔和铸件表面烧伤等缺陷,解决了铸件的泄漏问题,铸件品质得到大幅提升。     

铝合金零件半固态模锻的应用及发展

介绍了半固态模锻的实质及工艺过程;列举了半固态模锻铝合金零件的应用现状;阐述了半固态模锻工艺的优点。     

铝挤压工模具技术的发展

简要地论述工模具在铝合金挤压生产中的重要作用与特殊地位;介绍铝挤压工模具技术的主要内容;着重分析了国内外挤压工模具设计制造水平及创新亮点,铝挤压工模具的使用、修理、氮化技术及现代化管理工具.     

镁合金铸件缺陷补焊技术

铸造镁合金ZM5及ZM6得到越来越广泛的应用，而镁合金在铸造、机械加工和运输过程中产生的缺陷严重地影响了产品的合格率和交货期。主要阐述了采用交流钨极氩弧焊的方法修补ZM5及ZM6铸镁合金件局部缺陷的技术。     

Influence of casting defects on fatigue behaviour of A356 aluminium alloy

Abstract

The fatigue behaviour of A356 cast aluminium alloy under 10⁴ cycles was investigated by a servo-hydraulic machine at the temperature of 150°C. The specimens for the fully reversible tension compression tests were cut from cylinder head castings of automobile engines. The testing data were treated by S–N curve and the staircase method and the mean values of fatigue property coincided with each other by these two methods, though the data scattered with different casting defects. The fracture surfaces of fatigue specimens were examined by OM, SEM and EDS. It was found that in most of the specimens two or more fatigue crack initiations appeared at a fracture surface. Compared with casting defects such as oxide film, inclusion and blowhole, shrinkage porosity is more detrimental to the fatigue behaviour of aluminium alloy castings.     

ZL112Y压铸铝合金摩托车零件的半固态高压铸造成形

采用高频感应加热装置和温度测定装置，研究了ZL112Y压铸铝合金坯料高频感应加热二次重熔合适的半固态重熔温度、加热功率和速度，以及这些工艺参数对坯料的触变性能和微观组织的影响。结果表明：该合金合理的半固态二次重熔温度为570～571℃；在优化的感应加热工艺条件下，半固态重熔坯料内部的温差在0～1℃；半固态重熔过程使原始料坯中的α枝晶组织变成球团状和节杆状组织，满足了半固态触变成型的要求。采用实验室所获得的二次重熔工艺成功地压铸成形了JH70型摩托车发电机支架零件。     

激光技术在铝合金铸造液位控制中的应用

介绍激光技术在铝合金铸造过程中液位自动控制方面的应用，以及对提高扁锭质量的作用。     

Strengthening technology and mechanism for semi-solid die casting of aluminum alloy

Combined with theoretical evaluation,an optimized strengthening process for the semi-solid die castings of A356 aluminum alloy was obtained by studying the mechanical properties of castings solution treated and aged under different conditions in detail,then,the semi-solid die castings and liquid die castings were heat treated with the optimized process.The results show that the mechanical properties of semi-solid die castings of aluminum alloy are superior to those of the liquid die castings,especially the strengthening degree of heat treated semi-solid die castingsis much greater than that of liquid die castings with the tensile strength more than 330 MPa and the elongation more than 10％,and this is mainly contributed to the non-dendritic and more compact microstructure of semi-solid die castings.The strengthening mechanism of heat treatment for the semi-solid die castings of A356 aluminum alloy is due to the dispersive precipitation of the second phase(Mg2 Si) and formation of GP Zone.     

MIG and laser welding of aluminium alloy pressure die cast parts with wrought profiles

Using pressure die cast parts offers new possibilities for producing lightweight complex structures. A typical example is represented by the combination of different aluminium alloy extruded profiles joined by means of cast joints acting as connecting parts. A well-known application of this technique is the manufacture of the AUDI A8 (Fig. 1) as well as the second generation AUDI A2 body. The constituent elements of the joints, with their complex geometry, can be produced economically by pressure die-casting.     

Compression behaviour of semisolid YL112 die casting aluminium alloy following isothermal heat treatment

Abstract

The semisolid compression deformation behaviour of YL112 die casting aluminium alloy with the non-dendritic and dendritic structures has been compared in tests using a Gleeble-1500 thermomechanical simulator. The non-dendritic structure was obtained by isothermal treatment at 570°C for 120 min. In tests up to compressive strains of 0·8, the semisolid compression stress of the alloy with non-dendritic structure initially increases rapidly with increasing strain, then decreases, before reaching a plateau value. Under different deformation temperatures and deformation rates, the maximum compressive stresses are obtained in all cases at strain values of ～0·07. The semisolid deformation stress decreases with increasing deformation temperature and increases with increasing deformation rate. The compression behaviour of the two types of alloy differs. The semisolid compression stress of the alloy with dendritic structure is higher than that of the alloy with non-dendritic structure; and for strains >0·07, the semisolid compression stress increases and decreases with increasing strain for alloys with dendritic and non-dendritic structures respectively.