摘要
为了研究Al-Cu共晶合金钎料中Cu元素在钎焊接头中的扩散行为,采用快速凝固技术制备了Al-Cu共晶合金钎料,以纯铝棒料为基体采用对接接头在不同温度下进行了真空钎焊,并利用SEM和EDS对接头进行了研究.研究表明:钎料中Cu原子的扩散以晶界扩散为主,当晶界上Cu原子的浓度达到一定值后开始向晶内扩散,当晶内的Cu原子饱和后又反向扩散到晶界上;钎焊温度过低、保温时间过短时,Cu元素在基体内部不能充分扩散,在基体晶界上产生严重偏析,生成Al-Cu相中最脆的θ相(Al2Cu);提高钎焊温度和保温时间有利于提高Cu元素在Al基体中的扩散,但过高的钎焊温度又导致θ相的重新出现,选取合适的钎焊工艺参数才能获得良好的钎缝.
The diffusion phenomenon of element Cu in the joint is observed by means of SEM and EDS to study and discuss the diffuse effect and final production of element Cu in different brazing temperature and heat dwell time. The Al - Cu eutectic brazing metal is made to braze pure aluminium matrix in vacuum. The results indicate that the diffusion of element Cu is not complete at low brazing temperature and short dwell time. It comes into being the θ phase （ Al2 Cu） which is the brittlest in all Al- Cu phase and forms serious segregation on the substrate＇ s grain boundary. Although enhancing the brazing temperature and dwell time could improve the diffuse ability of Cu, the exorbitant brazing temperature would cause the reappearance of the θ phase. It is important to choose the best technical parameter for getting the best quality joints.
出处
《材料科学与工艺》
EI
CAS
CSCD
北大核心
2007年第3期383-386,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)
关键词
真空钎焊
Al-Cu共晶
扩散
扩散通量
晶界扩散
vacuum brazing
Al- Cu eutectic
diffusion
diffusion flux
grain boundary diffusion
