粉末冶金镁合金中第二相的扩散行为

Diffusion behavior of intermetallic compounds in powder metallurgy magnesium alloys

对传统粉末冶金和激光增材制造镁合金研究进展进行综述,并整理文献报道镁合金化合物扩散系数实验数据,从第二相金属间化合物扩散生长行为角度,研究所涉及的重要化合物动力学信息。针对镁金属间化合物扩散生长和扩散系数实验数据缺乏的现状,提出一种高通量获取化合物扩散系数的计算方法。研究结果表明:金属间化合物的“界面扩散动力学”行为不仅影响粉末烧结时的冶金结合和致密化,而且会影响其在材料中的形貌和分布。将“多元金属间化合物”及有益的“亚稳相或亚稳结构”引入粉末冶金材料是进一步提高粉末冶金镁合金性能的有效手段。

The research progress of traditional powder metallurgy and laser additive manufacturing of magnesium alloys were summarized.The reported experimental data on the interdiffusion coefficient of intermetallic compounds(IMCs)in magnesium alloy were reviewed.The key kinetic growth behavior of the second phase involved in the powder metallurgy process were studied.Finally,in view of the lack of experimental data on the diffusion growth and diffusion coefficient of IMCs in magnesium alloys,a high-throughput calculation method for obtaining compound diffusion coefficient was presented.The results show that the"interface diffusion"behavior of IMCs affects the alloy bonding and densification during powder sintering,which can further affect its morphology and distribution in the material.Meanwhile,The introduction of"multi-component IMCs"or"metastable phase and structure"is an effective means to further improve the properties of powder metallurgy magnesium alloys.