AZ31变形镁合金的铜夹层扩散焊连接试验研究  

Experimental Study on Diffusion Bonding of AZ31 Alloy with Cu Foil Layer

作　　者：张维翔[1] 杜双明[1] 刘刚[1] 张庆安[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：《热加工工艺》2013年第3期168-170,173,共4页Hot Working Technology

摘　　要：选取厚度50μm的纯Cu箔作为夹层,在加热温度480℃、保温时间30min、压力10MPa、真空度1×10-2Pa条件下对AZ31B镁合金进行真空扩散焊连接,利用SEM、EDS、XRD、显微硬度计等测试方法对接头界面区域的显微组织和性能进行分析。试验结果表明,利用镁与铜原子互扩散在接头处形成扩散界面区,能够实现镁合金的可靠连接。焊接接头由靠近母材一侧的扩散过渡区和中间扩散区组成,其中扩散过渡区主要是Mg(Cu,Al)固溶体基体及弥散析出的Mg17(Al,Cu)12相,中间扩散区主要由Mg2Cu、MgCu2中间相和Mg(Cu)固溶体混合而成。在焊接接头界面区域内,显微硬度值呈现台阶式递增的分布规律,其中扩散过渡区的硬度高出镁基体15～20HV,而中间扩散区的硬度高出镁基体50～60HV。Choosing pure copper foil with 50 μm in thickness as interlayer, AZ31 alloy was joined by diffusion bonding at 480℃, holding for 30 rain, pressure of 10 MPa and the vacuum degree of 1.0×10^-2 Pa. The microstmcturc and property of AZ31B/Cu/AZ31B diffusion bonding joint were studied by SEM, EDS and microhardness test. The results show that the magnesium alloy can be reliably jointed by the mutual diffusion of copper and magnesium atoms to form a diffusion zone. The bonding joint consists of a interfacial diffusion region and a transitional zone which is closed to the base material in both sides. The transitional zone ~ composed of Mg （Cu,AI） solid solution base and Mg^7 （AI,Cu）~2 phase which is dispersively precipitated; the interracial diffusion region is a mixture of Mg2Cu, MgCu2 and Mg （Cu） solid solution. Within the diffusion bonding joint, the microhardness shows a stepped increase pattern, the microhardness of the transitional zone is 15-20 HV higher than the magnesium base, while in the interracial diffusion region, the microhardness is 50-60 HV higher than the Mg base.

关 键 词：镁合金 Cu夹层 扩散焊 显微组织 

分 类 号：TG453.9[金属学及工艺—焊接]