快速凝固Al-Cu钎料钎焊铝Cu对钎缝组织的影响

研究了快速凝固钎料中Cu元素在铝合金基体中的扩散现象和机制.采用快速凝固的方法制备出了Al-Cu合金的薄带,用差热分析法(DTA)测量了钎料熔点.根据熔点利用真空钎焊用Al-Cu钎料焊接纯铝,然后使用扫描电镜和能谱分析仪分析了焊缝的显微组织,对Cu元素的扩散现象进行观察,并分析了Cu的扩散行为.实验结果表明,由于快冷钎料组织均匀,表面能高,因此熔点比普通钎料低,且熔化区间窄.随着钎焊温度的升高和保温时间的延长,Cu的扩散效果越来越好;在同一温度下钎焊时,快冷钎料中Cu的扩散能力明显强于普通钎料.

Influence of Cu on microstructure of soldered joint in Al brazing with rapid-solidifying Al-Cu solder

Diffusion and mechanism of element Cu in the matrix of aluminum alloy were revealed when rapid-solidifying Al-Cu solder was used for soldering.The ribbon of Al-Cu alloy was prepared by means of rapid solidification,and its melting point was tested with method of differential thermo-analysis(DTA).According to this melting point,pure aluminum was soldered in vacuum environment with this Al-Cu solder,and then the microstructure of the soldered joint was analyzed with scanning electron microscope and spectrometer.Meantime,the phenomenon of diffusion of element copper was observed and its diffusion behavior analyzed.It was shown by the experimental result that,due to the homogeneous structure of rapid-solidified solder and its high interface surface energy,its melting point is lower than that of traditional solders,melting area is narrow,and the effect of Cu-diffusion becomes even better along with the increase of soldering temperature and prolonging of heat-retaining period,so that the diffusibility of Cu in rapid-solidifying solder is remarkably higher than that of traditional solders when the soldering temperature is identical.