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

• 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

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) 设计并安装了具有四个横向布置的液压执行机构的材料试验机，其能力<+]->16吨。采用微机，操作控制方便，可目视观察并精确测量当前冲头载荷和冲程。2）进行铝试件叠加静水压镦冷自熔焊接实验，配备了压力传输介质专用镦粗工装和试验装置。还详细阐述了实现连接界面扩展达 10 倍以及对最小长度 6 毫米的焊接样本进行拉伸试验的技术。当静水压力为 30 kgf 时，可实现最佳粘合。 <mm^(-2)>仅在镦粗的最后阶段施加在侧表面上，而整个过程或过程早期的压力叠加会恶化粘合。样品纵向截面的显微镜检查表明，高压增加了钢丝拉丝表面层的延展性，从而减少了原始金属表面的面积，同时提高了原始金属界面的结合强度。因此，观察到的接头强度可归因于压力的冲突效应。3)为了对双金属焊接中由于流动应力差异引起的异常变形和材料失效进行实验研究，开发了基于橡皮泥的模型材料。还装置了由脉冲电机和透明工具驱动的双冲压机压缩测试仪，用于侧向和前向挤压实验。实验表明，当流动应力差较大且较硬层的厚度较小时，较硬的材料会失效。侧向挤压中较硬坯料的较窄宽度和正向挤压中较大的面积减少会促进失败。

项目成果

第35回塑性加工連合講演会論文集. (1984)

第 35 届塑料加工联盟会议论文集（1984 年）。