304不锈钢/铝扩散焊接界面组织与性能

以304不锈钢钢板作为基材,工业纯铝板作为过渡层,用真空扩散焊接的方法制备304不锈钢/铝/304不锈钢复合试样.利用光学显微镜、扫描电子显微镜、能谱仪和X射线衍射仅对界面组织、化学成分、断口形貌和组成相进行分析.通过硬度和剪切试验测定界面的显微硬度和剪切强度.结果表明,不锈钢/铝界面发生了原子互扩散,生成了多种脆性金属间化合物,并在原子扩散界面形成了不同层次的过渡组织.扩散层厚度随着加热温度的升高和保温时间的延长而增大.界面显微硬度值显著增大,剪切强度随着保温时间的延长先增加后降低.

Microstructure and Properties of Diffusion Welded Interface of 304 Stainless Steel-Aluminum

The composite sample of 304 stainless steel/A1/304 stainless steel was prepared by diffusion weld- ing in the vacuum using commercially pure aluminum as a transition zone. The interface microstructure, chemi- cal composition, fracture morphology and phases were measured by optical microscope, scanning electron micro- scope, energy dispersive spectroscopy, X-ray diffraction. The shear strength and microhardness near the inter- face were tested by shear and microhardness tests. The results show that the interfaces of SS/A1 forms a variety of brittle intermetallic compounds because of the elemental diffusion and different levels of transition products formed at the diffusion interface. The thickness of transition zone increases with the rising diffusion temperature and extending holding time. The microhardness of the interface increases obviously, and the shear strength of the interface first increases and then decreases with the extending the holding times.