镁/铝双金属固液复合界面的研究

Solid-liquid bonding interface of magnesium/aluminum bimetallic composites

用光学显微镜(OM)、扫描电子显微镜(SEM)、能谱仪(EDS)和显微硬度计等分析ZL105铝合金和Mg真空固液复合结合区的显微组织、相组成、元素分布和显微硬度。结果表明:当温度为430℃、保温60 min时,得到的ZL105/Mg双金属材料缺陷少,结合区形成3个新相层,各层组织均匀、层间结合紧密、显微硬度趋势良好,最大硬度值为287.9HV;在结合区形成Al_3Mg_2和β-Mg17Al12两种金属间化合物,新相层中的A层为α-Mg枝晶和枝晶间连续网状分布的β-Mg17Al12共晶组织,B层为富Al的α等轴细晶,C层主要为铝基固溶体和Al_3Mg_2。

The microstructure, phase composition, elements distribution and microhardness of the diffusion bonded interface layer for ZL105 aluminum/magnesium were analyzed by means of optical microscope （OM） , scanning electron microscopy （SEM） and energy spectrometer （EDS） , and microhardness tests. The results show that the ZL105 aluminum/magnesium bimetallic materials have fewer defects when the temperature is 430 ℃ and the holding time is 60 min. And then three new phase layers with uniform microsturcture of each layers and tight integration between layers are formed in the bonding zone. The microhardness trend is well and the maximum is 287.9HV. The A13Mg2 and 13-MgITAI12 intermetallic compounds are formed in the bending zone. The A layer is vt-Mg dendrite and 13-Mg1TAI12 eutectic structure with continuous interdendritic distribution, the B layer is an Al-rich a-equiaxed fine crystal, and the C layer is solid solutions with Al-matrix and AI1Mg2 phase.