Cu/Al异质接头的钎焊：一种新型低银Al-Ge-Ag中温钎料-中国材料进展

文章信息/Info

Title:: Brazing of Cu/Al Heterogeneous Joints: A Novel Medium-Temperature Low-Silver Al-Ge-Ag Filler Metal

作者:: 崔敏; 张顺猛; 熊凯; 何俊杰; 叶运炀; 张硕; 杨瑞霞; 闻明; 毛勇; 1. 云南大学材料与能源学院材料基因研究中心，云南昆明 650500 2. 云南贵金属新材料控股集团有限公司国家重点贵金属功能材料实验室，云南昆明 650106 3. 云南国土资源职业学院商务信息学院，云南昆明 652501

Author(s):: CUI Min; ZHANG Shunmeng; XIONG Kai; HE Junjie; YE Yunyang; ZHANG Shuo; YANG Ruixia; WEN Ming; MAO Yong; 1. Materials Genome Institute, School of Materials and Energy, Yunnan University, Kunming 650500, China 2. State Key Laboratory of Precious Metal Functional Materials, Yunnan Precious Metal New Materials Holding Group Co., Ltd., Kunming 650106, China 3. School of Business and Information, Yunnan Land and Resource Vocational College, Kunming 652501, China

Keywords:: Cu/Al heterogeneous joints; brazing; Al-Ge-Ag filler metal; microstructure; shear strength

摘要:: Cu/Al异质接头在新能源领域应用潜力巨大，但二者物化性质差异导致界面易形成脆性金属间化合物，恶化接头性能。开发新型钎料并优化工艺是实现接头高性能连接的关键。基于ThermoCalc热力学计算，设计并制备了一种低银Al-Ge-Ag三元共晶钎料（AlGe25.5Ag5，下标为原子数分数）。DSC测量显示该钎料固相线与液相线温度分别为417.26和436 ℃，熔程较窄，满足Cu/Al异质接头钎焊需求。XRD、SEM和EDS分析表明该铸态钎料合金由Al相、Ge相及Ag2Al相组成，与预测一致。采用该钎料在真空中成功实现Cu/Al钎焊，系统研究钎焊温度（500，520和540 ℃）对接头剪切强度的影响。结果表明，520 ℃时钎焊接头界面结合良好，无缺陷，主要生成Cu3Al2与Al2Cu化合物，接头剪强度最高（38.2 MPa）。为Cu/Al异质连接提供了一种新型中温低银钎料，并为钎焊工艺优化提供了数据支撑。

Abstract:: Cu/Al heterogeneous joints show significant application potential in new energy applications, but their prominent substantial physicochemical properties differences lead to the formation of brittle intermetallic compounds at the interface, compromising joint performance. Developing novel brazing filler metals and optimizing the process are key to achieving highperformance joints. Based on ThermoCalc thermodynamic calculations, this study designs and prepares a low-silver Al-Ge-Ag filler metal (AlGe255Ag5, at%). DSC results of the filler metal indicate solidus and liquidus temperatures of 417.26 and 436 ℃, respectively, with a narrow melting range, suitable for Cu/Al heterogeneous brazing. XRD，SEM and EDS analysis confirm that the as-cast alloy consists of Al, Ge and Ag2Al phases, consistent with predictions. Using this filler metal, successful vacuum brazing of Cu/Al is achieved, and the effect of brazing temperature (500, 520 and 540 ℃) is systematically investigated. Results show that joints brazed at 520 ℃ exhibit excellent interfacial integrity without defects, primarily forming Cu3Al2 and Al2Cu compounds and achieve the highest shear strength of 38.2 MPa. This study provides a novel mediumtemperature low-silver filler metal for Cu/Al heterogeneous joining and offers data support for brazing process optimization.