基于摩擦加工技术的镁合金表面改性研究现状

鉴于当前高性能镁合金的应用需求,亟待提高镁合金的表面硬度、摩擦磨损性以及耐蚀性等表面性能。新型固态加工技术——搅拌摩擦加工以及摩擦堆焊能够实现材料的大塑性变形,在镁合金表面微观组织结构改性、表面复合材料化以及金属焊敷层制备等方面得到了成功的应用。在介绍搅拌摩擦加工以及摩擦堆焊技术特性的基础上,分别从工艺手段、组织演变以及性能改善等方面综述了摩擦加工技术用于镁合金表面改性的研究现状。国内外研究结果显示,搅拌摩擦加工可有效细化镁合金表面晶粒,破碎粗大第二相,导入增强粒子,实现表面复合化,进而显著提高镁合金的硬度、耐磨性以及耐蚀性。摩擦堆焊技术可在镁合金表面成功制备无稀释、结合完整性高、均匀细化的金属焊敷层,有效改善镁合金表面硬度及耐磨性。通过对用于镁合金表面改性的摩擦加工技术研究现状的总结,展望了镁合金搅拌摩擦加工以及摩擦堆焊的发展前景,提出了需要进一步研究的方向。

Research Status of Surface Modification of Magnesium Alloys by Friction-based Processing Technology

In view of the application demand of high-performance magnesium alloys, surface hardness, friction-wear resistance and corrosion resistance of the magnesium alloys should be improved urgently. The novel solid processing technologies-friction stir processing and friction surfacing could generate severe material plastic deformation. Hence, they have been successfully applied to surface microstructure modification, preparation of surface composite and metal cladding layer on the magnesium alloys. Based on characteristics introduction of the friction stir processing and friction surfacing technology, the research status of friction processing technologies being applied to surface modification of magnesium alloy was reviewed in terms of techniques, microstructure evolution and performance improvement. The results of domestic and foreign studies showed that the friction stir processing could effectively refine grains on the surface of magnesium alloy, break up coarse second phase, introduce enhanced particles, achieve surface composite and further improve hardness, wear resistance and corrosion resistance of magnesium alloy. Friction surfacing technology could prepare non-diluted, integral and fine-grained metal cladding layer on the surface of magnesium alloy successfully, thus improving surface hardness and wear resistance of magnesium alloy. Based on the summary of the research status of friction-based processing technology applicable to surface modification of magnesium alloy, the development prospect of friction stir welding and friction surfacing of magnesium alloy was expected, the research direction to be further explored was put forward as well.