高性能镁合金增材制造技术研究进展

Research Progress in High-performance Mg Alloys Prepared by Additive Manufacturing

镁合金在航空航天、轨道交通、新能源、生物医用等领域具有广阔应用前景,增材制造技术(Additivemanufacturing)的发展为成形复杂结构的高性能镁合金构件提供了可能。然而,镁合金熔沸点低、蒸气压高、氧化性强的特点易使增材制造构件内部形成孔隙、裂纹、夹杂物等缺陷,导致增材制造镁合金的应用水平远远落后于高温合金、铝合金、钛合金等材料,开发适用于镁合金的增材制造技术并通过材料改性与工艺优化减少冶金缺陷是突破增材制造镁合金应用瓶颈的关键。镁合金增材制造技术主要有激光选区熔化(Selective laser melting,SLM)、电弧增材制造(Wire arc additive manufacturing,WAAM)以及搅拌摩擦增材制造(Friction stir additive manufacturing,FSAM)和搅拌摩擦沉积增材(Additive friction stir deposition,AFSD)。通过归纳梳理镁合金增材制造技术的研究现状与技术进展,总结了镁合金在不同增材制造技术成形过程中的数值模拟研究结果,对比分析了不同增材制造技术关键工艺参数对镁合金构件组织结构和力学性能的影响,并对镁合金增材制造技术未来的研究重点进行了展望。

Mg alloys have broad application prospects in aerospace,rail transit,new energy,biomedical and other fields.The development of additive manufacturing(AM)technologies has made it possible to form high-performance Mg alloys with complex structures.However,the characteristics of low melting and boiling points,high vapor pressure as well as strong oxidation activity of Mg alloys usually lead to the formation of pores,cracks,inclusions and other defects in the AM-prepared components,which results in the application level of AM-prepared Mg alloys far behind the superalloys,Al alloys,Ti alloys and other materials.Therefore,exploring more suitable AM technologies for Mg alloys and reducing their defects via material modification and process optimization are key solutions to break through the application bottlenecks of AM-prepared Mg alloys.The main AM technologies for Mg alloys include selective laser melting(SLM),wire arc additive manufacturing(WAAM),friction stir additive manufacturing(FSAM)and additive friction stir deposition(AFSD).The research status and technical progress of AM technologies for Mg alloys are reviewed.The numerical simulation results of Mg alloys forming process during different AM technologies are summarized.The effects of key processing parameters of different AM technologies on microstructures and mechanical properties of Mg alloys are comparatively analyzed.The future research directions of AM technologies for Mg alloys are also prospected.