中文摘要：

采用AlCl3-NaCl熔盐置换扩散工艺在AZ91D镁合金表面制备了镁铝金属间化合物涂层，并利用扫描电镜和XRD对镁铝金属间化合物进行表征。结果表明，熔盐自发置换扩散铝涂层在400℃、保温8h的工艺条件下呈现出明显的多层结构特征，从靠近镁合金基体至与熔盐接触的外层依次为δ（Mg）层→A112Mg17层→Al0．58Mg0.42层→Al3Mg2层→α（A1）层。镁合金表面熔盐自发置换扩散制备铝合金层的热力学分析为研究熔盐置换扩散铝舍金层的形成原理提供了理论依据。

英文摘要：

A dense and adhesive multilayer coating on AZglD magnesium is successfully obtained by AlC13 NaCl molten salt bath treatment at 673K for 8h. Morphology and elemental distribution through this layer has been studied with XRD, SEM/BSE. From magnesium substrate to the surface the diffusion alloying layer is mainly com- posed of Mg-A1 intermetallic compounds δ 9（Mg） layer→γ7（Al12 Mg17 ） layer→ε （ A10. s8 Mg0. 42 ） layer→β（Al3 Mg2 ） layer →α（A1） layer. Thermochemical analysis on the Mg-A1 intermetallic surface layer of magnesium alloy by treatment with molten AlC13-NaCl will instruct the molten salt surface treatment method.