镁锂超轻合金搅拌摩擦焊及其机制的研究

Study on Friction Stir Welding of Mg-Li Ultra-light Alloy and Its Mechanism

镁锂(Mg-Li)超轻合金作为一种新型超轻合金在国防军工及民生方面应用广泛。研究了国产双相Mg-Li合金LA103Z在搅拌摩擦焊后的力学性能、微观组织及显微硬度,并对其微观机理进行了分析。结果表明,Mg-Li超轻合金对搅拌摩擦焊呈现优良的可焊性,搅拌区未发现非致密性缺陷与裂纹,得益于其优良的塑性变形能力;搅拌区的强度与显微硬度均远高于母材,得益于其粗大α相的机械破碎及随后发生的破碎后α相碎屑的过饱和固溶。

As a new type of ultra-light alloy,Mg-Li alloy is widely used in national defense and people’s livelihood.The mechanical properties,microstructure and microhardness of domestic biphase Mg-Li alloy LA103Z after friction stir welding were studied.The results showed that Mg-Li ultra-light alloy presented excellent weldability for friction stir welding,and no non-compact defects or cracks can’t be found in the mixing zone,this is due to its excellent plastic deformation ability;the strength and microhardness of the stirring zone were much higher than that of the base material,which is due to the mechanical breaking of the coarseαphase and the subsequent supersaturated solid solution of the crushedαphase debris.