大截面铸铝-铸钢摩擦焊接接头显微分析

Microstructure analysis of large cross-section cast aluminum-steel friction welded joints

采用连续驱动摩擦焊技术对大截面铸铝与铸钢异种金属进行了焊接试验,通过电子探针、透射电镜、X射线衍射分析及微区硬度测试,进行了铸铝与铸钢异种金属焊接接头的显微分析.结果表明,大截面铸铝与铸钢间具有良好的摩擦焊接性;主要元素以界面为起点向对偶面扩散,Fe原子扩散距离稍小于Al原子的扩散距离;次生摩擦面对碳诱导形成碳化物;在焊缝区,既存在晶体,又存在非晶;接头焊合区两侧硬度均略高于基材.

Welding test for large cross-section cast aluminum and cast steel (dissimilar metals) by continuous drive friction welding technology was conducted. By means of electron microprobe, transmission electron microscopy, X-ray diffraction analysis and micro-hardness testing, the welded joints between cast aluminum and steel were analysed. The results show that the joints between the large cross-section cast aluminum and steel has a good friction weld ability, the main elements diffuse to the dual surface from the interface which is as the starting point, diffusion distance of iron atoms is slightly less than that of aluminum atoms, carbon is induced by secondary friction face to form carbide, not only crystal but also amorphous exist in the weld zone, and the hardness on both sides of weld joint zone is slightly higher than that of the substrate.