Sn-Zn钎料钎焊镁合金AZ31B接头的显微组织及力学性能  

Microstructure and Mechanical Properties of AZ31B Magnesium Alloy Brazed Joint Using Sn-Zn Filler Metal

作　　者：韩秉达 杜双明[1] 

机构地区：[1]西安科技大学材料科学与工程学院,陕西西安710054

出　　处：《铸造技术》2015年第7期1836-1839,共4页Foundry Technology

摘　　要：以Sn-Zn钎料对变形镁合金AZ31B进行了炉中钎焊,研究了变形镁合金AZ31B钎焊接头的微观结构与连接强度。采用XRD、SEM、EDS等仪器分析了钎焊接头的界面组织和钎缝物相,测试了钎焊接头的剪切强度与钎缝组织的显微硬度。结果表明,Sn-Zn钎料在钎焊过程中与母材AZ31B发生溶解与扩散作用,在钎缝中生成金属间化合物Mg2Sn和(β-Sn+Mg2Sn)共晶组织。钎焊接头中母材的显微硬度最低,Mg2Sn的显微硬度最高,钎焊搭接接头平均抗剪切强度达到48 MPa。钎焊搭接接头的主要断裂形式为沿晶脆性断裂,断裂主要发生在共晶组织和Mg2Sn相处。AZ31B magnesium alloy was soldered by means of furnace brazing using Sn-Zn filler metal. Microstructure, phases, interface and shearing strength of AZ31B brazed joint were studied by XRD, SEM, and EDS. The results show that Sn-Zn filler metal dissolve and diffuse with AZ31B matrix during soldering. Mg2Sn and β-Sn＋Mg2Sn are formed in the brazing joint. The highest microhardness of joint zone is Mg-Sn phase, and the average shearing strength is 48MPa. The main fracture form is intergranular brittle fracture, and the fracture occurred at the eutectic structure and hard brittle Mg2Sn phase.

关 键 词：AZ31B合金 Sn-Zn钎料 真空钎焊 显微组织 

分 类 号：TG407[金属学及工艺—焊接] TG454