高强度ZA合金钎焊接头的显微组织及性能

Microstructure and characteristics of soldered joint of high strength ZA alloy

用光学显微镜、扫描电镜、X射线衍射等分析手段 ,对高强度ZA合金钎焊接头的显微组织形态及其特征、性能及界面区的相组成等进行了研究分析。结果表明 ,用研制的新型高强软钎料钎焊高强度ZA合金获得的钎焊接头在界面区局部有交互结晶产生 ;界面区组织构成较复杂 ,既有Cd、Sn、Zn固溶体 ,又有少量的细小的Mg2 Sn、MgZn等化合物 ;固溶体可以提高钎焊接头的强度和韧性 ,少量细小的化合物可强化基体组织 ,有利于强度的提高 ;但连续层状的金属间化合物可引起钎焊接头的脆化 ,使其性能降低。测试结果表明钎焊接头具有较高的力学性能 。

The microstructure and characteristics, properties and phase composition of soldered joint were investigated by optical microscope, scanning electron microscope and X-ray diffraction. The results show that interactive crystallization exists in the interfacial region by using a new developed high strength soldering filler metal. It is complex that the phases in interfacial region. Both solid solution of Cd, Sn, Zn and small amounts of fine grained compounds of Mg2Sn, MgZn are founded in the interfacial region. Solid solution could improve the strength and plasticity, and small amounts of fine grained compounds could strengthen the matrix which is beneficial to improve the joint strength. However, successive laminate of intermetallic compounds will result in embitterment and deteriorate the properties of the joint. The results also show that the properties and elongation percentage of the joint are higher than base material.