【摘要】 制备了 Al-Cu 其晶合金钎料,以纯铝棒料为基体采用对接接头进行了真空钎焊。使用 SEM 和 EDS 对 Cu元素的扩散现象进行了观察,初步研究和讨论了不同钎焊温度和保温时间条件下 Cu 元素在基体中的扩散效果和最终产物。实验结果表明:钎焊温度过低、保温时间过短时,Cu 元素在基体内部未能充分扩散,在基体晶界上严重偏析,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 基体中的扩散效果,但过高的钎焊温度又导致θ相的重新出现。选取最佳的钎焊工艺参数才能获得良好的钎缝质量。更多还原

【Abstract】 The Al-Cu eutectic brazing alloy is made to braze the pure aluminium substrates in vacuum.The diffusion phenomenon of element Cu is observed by means of SEM and EDS.The diffusion effect of Cu and final products in the substrate at different brazing temperature and heat preservation time are studied and discussed.The results indicated that the diffusion of Cu is not complete at low brazing temperature and short heat preservation time.It comes into being the θ phase（Al₂Cu）,which is the most brittle phase in all Al- Cu phases,and forms serious segregation on the substrate’s grain boundary.Although enhancing the brazing temperature and holding time could improve the diffusion effect of Cu,the exorbitant brazing temperature would cause the reappearance of the θ phase.It is important to choose the optimal technical parameters for getting the best quality of the welding line.更多还原