摘要
使用A l-Cu共晶合金快冷钎料,以纯铝棒料为基体进行了真空钎焊.采用大间隙对接接头,使熔化后的钎料在毛细和重力作用下产生堆积,清楚地观察到了"钎料残余层"的存在.使用SEM和EDS对Cu元素的扩散现象进行了观察,初步研究和讨论了Cu元素在液相和固相扩散区域的不同扩散行为.实验结果表明:钎料熔化初期Cu元素在浓度梯度的驱使下向基体扩散,低熔点组分流向基体而高熔点组分逐渐堆积形成"钎料残余层".在基体深度方向上,Cu元素主要沿基体晶界扩散,且随扩散深度的增加呈明显的线性分布状态.
The Al -Cu eutectic rapid solidification brazing metal was braed with pure aluminium as the substrate in vacuo. The melted brazing metal deposited under capillarity and gravitation, then the remnant layer was observed clearly. The diffusion phenomenon of element Cu was observed by means of SEM and EDS. The different diffusion actions of element Cu in liquid and solid zone were studied. The results indicate that the element Cu diffuses toward the substrate driven by the concentration grads in the initial stages of melting. The components with the low melting point flow toward the substrate and the phase with the high melting point de- posits gradually and then forms the remnant brazing metal layer. The element Cu diffuses along the grain boundary of the substrate in depth direction and presents an obvious linear distribution with the increasing of the diffusion depth.
出处
《材料科学与工艺》
EI
CAS
CSCD
北大核心
2008年第5期675-678,共4页
Materials Science and Technology
基金
甘肃省中青年科技基金资助项目(YS021-A22-017)
