铱与镍基合金焊接接头的组织与性能分析

为解决原有火花塞中心电极焊接工艺造成的贵金属用量多、焊接不牢靠以及易产生裂纹、气孔等问题,通过电子探针(EPMA)研究了不同焊件结构对焊接区域的元素的扩散、材料之间的冶金结合的影响,通过扫描电镜(SEM)研究了不同结构对焊接区域断口界面组织的影响,同时测试了不同结构焊件样品的电阻率及弯折强度。结果表明,采用平面结构焊接,确保了焊接端面的接触,有利于材料的冶金结合,虽然弯折强度降低了11. 6%,但是整体焊接稳定性有所提升,同时大幅度降低了焊接气孔生成的几率,降低了平均电阻率,提高了整体性能。

Microstructure and properties of iridium and nickel base alloys welded joint

In order to solve the problems, such as cost of precious metals, unstable welding strength and welding defects like crack and pores, existing spark plug center electrode welding process, the influence of different structures on the element diffusion and metallurgical combination between two materials was studied by electron probe micro-analyzer (EPMA) and the welding area fracture morphology was studied by scanning electron microscopy (SEM). Besides, the resistivity and welding strength of samples were tested. The results showed that the flat welding structure ensured the welding contact area, which was beneficial to the metallurgical bonding of the material. Although the bending strength reduced by 11.6%, the overall welding stability was improved and probaility of welding porosity was greatly reduced. Meanwhile, the average resistivity reduced and the overall performance was improved.