【摘要】 以Al-Mg-Zn钎料对变形镁合金AZ31B进行了高频感应钎焊,分析了变形镁合金AZ31B钎焊接头的显微组织、钎缝物相和力学性能.采用扫描电镜(SEM)、X射线衍射仪(XRD)、X射线能谱分析仪(EDS)等仪器分析了钎焊接头的界面组织及钎缝生成相,测试了接头的强度及形成相的显微硬度.结果表明,在钎焊接头的钎缝中钎料与母材AZ31B发生反应生成离异共晶组织-αMg+-βMg17(Al,Zn)12,母材AZ31B的显微硬度最低,钎缝中的-βMg17(Al,Zn)12相显微硬度最高.对接和搭接接头断口的断裂形式为沿晶脆性断裂,断裂产生在离异共晶组织-αMg+-βMg17(Al,Zn)12中的-βMg17(Al,Zn)12硬脆相处.更多还原

【Abstract】 High-frequency induction brazing of wrought magnesium alloy AZ31B with Al-Mg-Zn filler metal was investigated.Microscopic structure,the phases and the mechanical properties of brazed joint were studied.The microstructure and formation phases at the interface in the brazed joint were investigated by scanning electron microscopy(SEM),X-ray diffraction instrument(XRD) and energy dispersive spectrometer(EDS).The strength of the brazed joint and the microhardness of the formation phases were also tested.The results show that,Al-Mg-Zn filler metal reacting with the base metal AZ31B,and α-Mg+β-Mg17(Al,Zn)12 divorced eutectic structure is formed in the brazed joint.Microhardness of the base metal AZ31B is the smallest and β-Mg17(Al,Zn)12 phase of the brazed joint is the hardest.Both the butt joint and the overlap joint exhibit intergranular fracture mode,the fracture comes from hard brittle phase β-Mg17(Al,Zn)12 of α-Mg+β-Mg17(Al,Zn)12 divorced eutectic structure.更多还原