Microstructure Evolution Mechanism of Ultra-Thin Dual Phase Magnesium–Lithium Alloy during Asymmetric Warm Rolling

Abstract

Magnesium–lithium alloy is the lightest metal alloy material so far, and the ultra-thin plate is also one of the main trends in the future development of Mg-Li alloy. In order to explore how to prepare LZ91 ultra-thin Mg-Li alloy, this topic adopts the combination of the finite element method (FEM) and visco-plastic self-consistent (VPSC) calculation, electron back-scattered diffraction (EBSD) and tensile experiment, and uses the asymmetric warm rolling process to realize the processing of ultra-thin LZ91 Mg-Li alloy plate with a thickness of 0.25 mm. The experimental results show that the maximum basal texture strengths of 1 mm initial plate and 0.25 mm ultra-thin rolled plate are 36.02 mud and 29.19 mud, respectively. The asymmetric warm rolling process not only reduces the basal texture strength but also significantly refines the grains. The tensile strength and yield strength of 0.25 mm ultra-thin rolled plate along the rolling direction reached 206.8 MPa and 138.4 MPa, respectively. This has a positive effect on the mechanical properties of subsequent materials. VPSC results show that the base slip is the main factor in Mg-Li alloy asymmetric warm rolling, and a large number of tensile twinning are initiated due to the coordinated deformation of the body-centered cubic (BCC) phase, which is beneficial to improve the plastic deformation capacity of Mg-Li alloy.

Plastic Deformation Mechanism of High Strength and Toughness ZK61 Magnesium Alloy Plate by Multipass Horizontal Continuous Rolling

“…Chen [ 10 ] studied the microstructure change of ME21 rare earth magnesium alloy based on VPSC model. An [ 11 ] studied the evolution law of dual-phase structure of ultra-thin Mg-Li alloy during asymmetric warm rolling. However, the latter are expensive and difficult to popularize.…”

Room Temperature Strengthening and High-Temperature Superplasticity of Mg-Li-Al-Sr-Y Alloy Fabricated by Asymmetric Rolling and Friction Stir Processing

“…Magnesium-lithium (Mg-Li) alloys have found certain applications in the automobile industry, 3C (Computer, Communication, and Consumer Electronic) electronics, weapons, and spaceflight industries owing to their extremely low density, excellent specific stiffness, good specific strength, good electromagnetic shielding properties, and damping properties. Due to the demand of aviation and spaceflight industries, studies on the room temperature microstructure, mechanical properties, and strengthening have been reported in some Mg-Li alloys [ 1 , 2 , 3 , 4 ]. Meanwhile, investigations into the superplasticity and hot deformation of Mg-Li alloys attract extensive attention because aerospace environment sustains the temperature difference up to 423 K, and high-temperature performance is urgently required [ 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 ].…”