四种纯金属真空钎焊接头的组织和硬度

Microstructure and Hardness of Vacuum Brazing Joints for Four Kinds of Pure Metals

采用60%BNi-2+40%BNi-5混合镍基钎料对四种纯金属铁、镍、钼、铬进行了真空钎焊,运用光学显微镜、扫描电镜、能谱仪、X射线衍射仪及硬度仪等对钎焊接头显微组织、钎缝成分分布、物相组成和显微硬度进行了分析。结果表明:纯铁和纯铬的钎缝中硅、硼元素扩散不充分,均生成了脆性化合物,使接头硬度较高;纯镍和纯钼的钎缝完全由固溶体组成,硬度较低,同时钎焊纯镍的接头界面处产生了空洞,使其硬度最低。

Vacuum brazing of pure Fe, Ni, Mo, nickle-based composite fillers. The microstructure, Cr metals was performed using 60%BNi-2＋40%BNi-5 the composition distribution, phase composition and microhardness of the brazed joints were investigated using optical microscopy, scanning electron microscopy, energy spectrometer, X-ray diffractometer and microhardness tester. The results indicate that Si and B in the brazing seam diffused insufficiently when the base metals were pure Fe and Cr, forming brittle compounds in the seam, the hardness of joint was higher. The brazing seam of pure Ni, Mo metals were completely composed of solid solution, its hardness was lower and at the same time the voids generated at the interface of the joint when pure Ni metal was brazed, the hardness of joint was lowest.