FUNDAMENTAL STUDY OF MECHANICAL BONDING AND SEPARATION OF DUCTILE METALS

延展性金属机械粘合和分离的基础研究

基本信息

批准号：
58420023
负责人：
KUDO Hideaki
金额：
$ 16万
依托单位：
Yokohama National University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (A)
财政年份：
1983
资助国家：
日本
起止时间：
1983 至 1985
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-58420023/
关键词：
aluminium plasticine cold pressure welding upsetting sideways extrusion forward extrusion multi-ram material testing machine ワイヤブラシ層

项目摘要

1) A material testing machine with four crosswise arranged hydraulic actuators of a <+]-> 16 tonf capacity was designed and installed. By the use of a microcomputer , easy operation and control of the machine, visual watch and precise measurement of current punch loads and strokes were made feasible.2) To carry out experiments in cold autogenous welding by upsetting of aluminium specimens under superimposed hydrostatic pressure, a special upsetting tooling and a test equipment for pressure transmission medium were deviced. Techniques to attain expansions of joining interface up to 10 and to conduct tensile tests of welded specimens of a minimum length of 6 mm were also elaborated. The best bonding was achieved when a hydrostatic pressure of 30 kgf. <mm^(-2)> was imposed on the side surfaces only at the final stage of upsetting, while superposition of the pressure throughout or in the early period of the process deteriorated bonding. Microscopic examination of longitudinal sections of the specimens indicated that the high pressure increased ductility of the wire-brushed surface layers thus reducing the area of virgin metal surface, while it raised the bond strength at the virgin metal interface. The observed joint strengths were thus attributable to the conflicting effect of pressure.3) For an experimental investigation of abnormal deformation and material failure in bimetallic welding due to the difference in flow stress, model materials based on plasticine were developed. A two-ram compression tester driven by pulse-motors and transparent toolings for sideways and forward extrusion experiments were also deviced. The experiments revealed that the harder material failed when the flow stress difference was large and the thickness of harder layer was small. A narrower width of the harder billet in the sideways extrusion and a higher reduction in area in the forward extrusion promoted failure.

1）设计和安装了A <+] - > 16吨的材料测试机，具有四个横向布置的液压执行器。通过使用微型计算机，使机器的轻松操作和控制，可行的当前打孔负荷和笔触的视觉手表和准确的测量值可行。2）在叠加液压压力下损坏铝制标本，在冷自源焊接中进行实验。还详细阐述了达到10个最小长度的焊接样品的拉伸测试的连接界面扩展的技术。当静水压力为30 kgf时，达到了最好的键合。 <mm^（-2）>仅在沮丧的最后阶段施加在侧面表面，而在整个过程的早期或早期的压力叠加都会恶化。对标本的纵向切片的显微镜检查表明，高压增加了丝网表面层的延展性，从而降低了维珍金属表面的面积，而它提高了Virgin Metal界面的键强度。因此，观察到的关节强度归因于压力的冲突作用。3）对于由于流动应力差而引起的双金属焊接异常变形和材料故障的实验研究，开发了基于罗斯非的模型材料。由脉搏运动和透明工具驱动的两杆压缩测试仪也偏离了侧向和正向挤压实验。实验表明，当流动应力差很大并且硬层厚度较小时，较难的材料失败。侧向挤压中较硬的钢坯的宽度较窄，并且向前挤压的面积较高促进了故障。