中文摘要：

采用单辊快速凝固法制备了Ag-Cu-Ge钎料薄带。利用差示扫描量热仪（DSC）、X射线衍射仪（XRD）分析钎料合金的熔化特性和相组成。用扫描电子显微镜（SEM）观察钎料合金和钎焊接头的显微组织,并用能谱仪（EDS）进行微区成分分析。结果表明：快速凝固Ag-Cu-Ge钎料合金液相线降低了4.8℃,熔化区间减小了4.4℃;普通凝固钎料合金组织粗大,偏析严重,快速凝固钎料合金组织显著细化,成分更加均匀;与普通凝固钎料相比,快速凝固Ag-Cu-Ge钎料在铜和镍基体上的润湿性和铺展性更好,过渡层的厚度更宽,钎焊接头剪切强度更高;钎料合金与铜基体形成层状固液同分化合物,而与镍基体形成了笋状固液异分化合物,这种嵌入式结构有利于提高钎焊接头的牢固性。

英文摘要：

Ag-Cu-Ge solder ribbons were prepared by single roller rapid solidification technology. Melting temperature and phase composition of solder alloys were determined by differential scanning calorimetry（DSC） and X-ray diffraction（XRD）. The microstructure and morphology of solder alloys and brazing joints were observed by scanning electron microscope（SEM）, and their chemical composition was analyzed by energy dispersive spectrometer（EDS）. The results show that the liquidus temperature of rapidly solidified Ag-Cu-Ge solder decreases by 4.8 ℃ and its melting temperature range reduces by 4.4 ℃. The microstructure of commonly solidified solder is massive and heavy segregation, while rapidly solidified solder has finer microstructures and higher composition homogeneity. Rapidly solidified Ag-Cu-Ge solder with Cu and Ni substrate has a better wettability and spreadability, thicker transition layer and higher shear strength of brazed joints, compared with commonly solidified solder. Congruent compounds which grow up as a layer are found on the interface of solder alloy with copper substrate, while incongruent compounds which grow up as bamboo shoot form are found on the interfaces of solder alloy and nickel substrate. This embedded structure is helpful to improve the strength of brazed joints.