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采用扩散连接方法在压力范围10~35 MPa、温度430~450°C、时间60 min,真空13.3 mPa条件下连接Al 7075和Mg AZ31合金。采用扫描电子显微镜、X射线能谱和X射线衍射分析合金的显微组织演变、相分析和元素分布。结果表明:25 MPa为最佳的压力条件,在此条件下接头发生最小的塑性变形;在界面过渡区可观察到含不同金属间化合物如Al_(12)Mg_(17),Al_3Mg_2和α(Al)的固溶体反应层;随着温度的升高,反应层的厚度增大,更多的铝原子扩散进入镁合金,且界面朝着铝合金移动;在温度440°C、压力25 MPa下得到最大的结合强度38 MPa。断口形貌研究表明,脆性断裂来自于Al_3Mg_2相。
The diffusion bonding method was used to connect Al 7075 and Mg AZ31 alloy under the pressure of 10 ~ 35 MPa, temperature of 430 ~ 450 ° C, time of 60 min and vacuum of 13.3 mPa. The microstructure evolution, phase analysis and elemental distribution of the alloy were analyzed by scanning electron microscopy, X-ray energy dispersive spectroscopy and X-ray diffraction. The results show that 25 MPa is the best pressure condition, and the minimum plastic deformation occurs in this condition. In the interfacial transition zone, different intermetallic compounds such as Al 12 Mg 17, Al 3 Mg 2 and Al (Al ) Solid solution reaction layer; as the temperature increases, the thickness of the reaction layer increases, more aluminum atoms diffuse into the magnesium alloy, and the interface toward the aluminum alloy; at a temperature of 440 ° C, the maximum pressure of 25 MPa The bonding strength of 38 MPa. Fractographic studies show that the brittle fracture comes from the Al 3 Mg 2 phase.