Research on Laser Welding and Superplastic Properties of LZ91 Mg-Li Alloy
LZ91 magnesium-lithium alloy is a structural material with ultra-low density and excellent plasticity.In this paper,LZ91 magnesium-lithium alloy plates are joined under different laser welding parameters.Uniaxial tensile tests were carried out at different temperatures(250 ℃,300 ℃)and strain rates(5×10-4s-1,1 ×10-3s-1),and the variation rules of flow stress and elongation were analyzed.The optimal forming condition for laser welding LZ91 magnesium-lithium alloy were determined as follows:the forming temperature is 300 ℃C,the strain rate is 5× 10-4s-1,the laser welding power is 940 W,and the welding speed is 1800 mm/min.The die design and macro finite element simulation for superplastic bulging were established,and the laser beam welded LZ91 magnesium-lithium alloy has good formability through superplastic bulging test.
Mg-Li alloylaser weldingsuperplastic formingfinite element simulation