【摘要】 采用扫描电镜 ,X射线衍射仪和透射电镜分析了Fe3 Al/ 1 8- 8扩散焊接头的显微组织特征。结果表明 ,加热温度 1 0 4 0℃、保温时间 6 0min、焊接压力 1 5MPa时获得的Fe3 Al/ 1 8- 8扩散焊接头抗剪强度达 2 2 6MPa。接头处形成具有三个扩散反应层的过渡区 ,其相结构依次由 (FeAl +Fe3 Al)、Ni3 Al相和α -Fe (Al)固溶体组成。显微硬度峰值为 6 1 0HM ,不存在FeAl2 ( 82 0HM)、Fe2 Al5( 990HM)和FeAl3 ( 1 0 30HM)等脆性相 ,有利于保证Fe3 Al/ 1 8- 8扩散焊接头的组织性能更多还原

【Abstract】 Fe₃Al intermetallic and 18-8 stainless steel were vacuum diffusion welded and an obvious Fe₃Al/18-8 diffusion welded joint with three reaction layers was formed. Microstructure and phase structure of the joint were researched by means of scanning electron microscope, X-ray diffractometry and transmission electron microscope. The results indicate that shear strength of the Fe₃Al/18-8 diffusion welded joint which was obtained at 1 040 ℃ for 60 min with a pressure of 15 MPa is up to 226 MPa. And there are FeAl, Fe₃Al, Ni₃Al phases and α-Fe （Al） solid solution from Fe₃Al to 18-8 in the joint. The peak microhardness was measured to be 610 HM and there were no brittle phases such as FeAl₂ （820 HM）, Fe₂Al₅ （990 HM）, FeAl₃ （1030 HM） .更多还原