铝合金/铜/不锈钢接触反应钎焊及晶界渗透行为分析  

Contact reactive brazing between Al alloy/Cu/stainless steel and analysis on grain boundary penetration behaviors

作　　者：吴铭方[1,2] 司乃潮[1] 浦娟[2] 

机构地区：[1]江苏大学,江苏镇江212013 [2]江苏科技大学,江苏镇江212003

出　　处：《焊接学报》2009年第11期85-88,共4页Transactions of The China Welding Institution

基　　金：江苏省研究生创新计划项目(CX08S008Z)

摘　　要：在Al/Cu接触反应钎焊接头中易出现晶界渗透.为此,通过6063铝合金/镀铜层/1Cr18Ni9Ti不锈钢的接触反应钎焊获得晶界渗透形貌,并对晶界渗透机理进行了初步探讨.结果表明,Al/Cu之间的晶界渗透现象十分显著,在接触反应钎焊温度为570℃,保温时间为60 min时,晶界渗透深度达到了200μm左右;原子向晶界扩散是产生晶界渗透的必要条件,但不是充分条件,产生晶界渗透的关键因素在于晶界与基体原子互扩散通量不等,促使空位向晶界迁移,大量空位向晶界迁移的结果造成晶界出现极其微小的沟槽直至产生细微裂纹,在毛细管力作用下,共晶液相被吸入显微沟槽,从而形成晶界渗透;1Cr18Ni9Ti不锈钢一侧界面反应层由Fe-Al金属间化合物构成,与之相邻区域主要含Cu-Al金属间化合物,焊缝组织由Al-Cu共晶及大块状铝的固溶体组成.Grain boundary penetration behavior occurs easily in the Al/Cu contact reactive brazing.In this paper,the mechanisms of formation and evolution of grain boundary penetration were investigated when contact reactive brazing between 6063 Al Alloy and 1Cr18Ni9Ti stainless steel was conducted using Cu as interlayer.The results show that the grain boundary penetration phenomenon is prominent.Grain boundary penetration depth was up to 200 μm when the brazing temperature was 570 ℃ and holding time was 60 min.The diffusion of atom into grain boundary was not sufficient but necessary for forming of grain boundary penetration.The key factor to induce grain boundary penetration was non-equilibrium diffusion of atom between the grain boundary and base metal,which led to crystal lattice expanding,and promoted the vacancy transferring into grain boundary,and resulted in a thin groove.And then,micro-cracks were formed in the grain boundaries,the eutectic liquid was sucked into the groove by capillary force,and finally grain boundary penetration was created.The interface reactive layer consisted of Fe-Al intermetallics(IMCs) in the side of 1Cr18Ni9Ti,the adjacent zone was Cu-Al IMCs,welded seam zone was composed of Al-Cu eutectic structure and large blocked Al solid solution.

关 键 词：铝合金 不锈钢 接触反应钎焊 晶界渗透 组织 

分 类 号：TG115.28[金属学及工艺—物理冶金]