In order to achieve brazing of magnesium alloy without brazing flux, a new AlSiCu amorphous alloy was designed as an intermediate layer. The contact reaction brazing method was used to brazing AZ31 magnesium alloy with AlSiCu amorphous alloy as an intermediate layer. The SEM and OM methods were used to analyze the structure of the brazing seam, and it was found that there were block, granular, and dendritic alloy phases in the brazing seam. The composition of the alloy phases in the brazing seam was measured by EDS analysis, and the intermetallic compounds of MgAl were found. Unfixed micro-holes were found in the brazing seam held at 450 °C for 15 min, and these micro-holes disappeared and a complete interface connection was formed in the brazing seam when the holding time increased to 20 min. With the increase of brazing time, the brazing seam became wider and the dendrite in the brazing seam began to spread towards the base metal and gradually decreased after holding for 25 min. After holding for 30 min, the dendrite disappeared and the second phase appeared as granular and short rod distribution, and the number decreased significantly. The joint strength increases significantly with the increase of holding time, and the tensile shear strength of the lap joint is 110 MPa. The average hardness of the brazing seam is 94.2 HV, the hardness values of the matrix phase and the second phase are different greatly. The probe was used to analyze the microstructure and morphology of the shear fracture, and it was found that cleavage patterns and dimples existed on the fracture surface at the same time.

为了实现无钎剂钎焊镁合金，设计了一种新型的AlSiCu非晶合金作为中间层。采用接触反应钎焊法，以AlSiCu非晶合金为中间层钎焊AZ31镁合金。采用SEM和OM方法对焊缝组织进行分析，发现焊缝中存在块状、粒状和树枝状合金相。通过EDS分析测量钎焊缝中合金相的成分，Mg的金属间化合物艾尔被发现了。450℃保温15分钟后，焊缝中出现未固定的微孔，当保温时间增加到20分钟时，这些微孔消失，焊缝内形成完整的界面连接。随着钎焊时间的增加，焊缝变宽，焊缝中的枝晶开始向母材扩散，保温25 min后逐渐减少。保温30 min后，枝晶消失，第二相呈粒状、短棒状分布，数量明显减少。随着保温时间的增加，接头强度显着增加，搭接接头的拉伸剪切强度为110 MPa。钎焊缝的平均硬度为94.2 HV，基体相和第二相的硬度值相差很大。用探针分析剪切断口的显微组织和形貌，发现断口同时存在解理图案和凹坑。