金属冷压焊结合机理的试验研究

EXPERIMENTAL INVESTIGATION ON JOINING MECHANISM OF METAL IN COLD WELDING

针对金属冷压焊的结合机理，采用中子活化、电镜扫描、光谱分析等测试手段对金属冷压焊接头界面原子扩散行为进行了综合试验测定，发现在所测试的冷压焊接头中不存在异种金属间的相互扩散行为。进一步对冷压焊接头界面区的透射电镜观察分析表明：接头界面区是由挤压碎化的细晶构成，碎化的细晶在界面处相互咬合增加了相焊金属间物理接触面积，形成碎化细晶之间的晶间结合，无需金属原子间的扩散就能实现结合。根据上述分析结果，实现了非共格金属间及液相、固相不相溶金属间的对接冷压焊。

Aiming at the joining mechanism of metal in cold welding, makes a comprehensive experimental determination to the diffusing action of atoms at the interface of cold welding joints by using a great deal of measuring experiments such as neutron activation, S.E.M., spectral analysis, etc. It is pointed that there is no diffusing action between different types of metal in the measuring cold welding joints. Further observation and analysis on the interface of cold welding joints by T.E.M., it is shown that joint interface area is composed of tiny crystals which are formed by extruding and breaking. These broken crystals bite on each other at the interface. This increases the physical contact area of the welded metal, forms intercrystal joint between broken crystals. So, the joining can be achieved without metal atoms diffusion. On the basis of the above analystic results, successful butt cold welding has been obtained between the metals of incoherent lattice and non soluble liquidoid and non soluble solidoid. Furthermore, it is shown the cold weldability between the various combination of different types of metal.