Mg/Al异种材料真空扩散焊界面区域的显微组织

Microstructure in interface zone of diffusion-bonded joint of Mg/Al dissimilar materials

摘要: 采用真空扩散焊技术对Mg/Al异种材料进行了焊接。采用金相显微镜、扫描电镜(SEM)、显微硬度计及X射线衍射(XRD)对扩散界面附近的显微组织及性能进行了试验研究。试验结果表明,Mg/Al异种材料真空扩散焊在加热温度T_p=450~490℃,压力强度P=0.08~0.10 MPa,保温时间t=40~60 min时能得到良好的扩散焊接头。扩散焊界面过渡区形成了致密的新相化合物层,断口形貌呈粗糙暗灰色,以解理断裂为主并伴有脆性的混合型断口,扩散界面过渡区生成了MgAl、Mg₃Al₂、Mg₂Al₃等金属间化合物。

Abstract: Magnesium (Mg1) and aluminum (1070 A) were bonded by vacuum diffusion bonding technology. The microstrueture of the Mg/Al diffusion bonded joint was studied by means of metallography, micro-hardness test, scanning electron microscope and X-ray diffraction. The diffusion bonding parameters: the heat temperature T_p=450-490℃,the pressure P=0.08-0.10 MPa, the holding time t=40-60 min.The experiment results indicated that the new compact phase was formed in the transition zone of Mg/Al diffusion bonded joint. The fracture morphology of Mg/Al diffusion bonded joint mainly consists of coarse and gray fracture, and the fracture is mainly the mixed fracture of cleavage.There are the intermetallic compounds MgAl, Mg₃Al₂ and Mg₂Al₃ in the diffusion transition zone.