Effect Of Electromagnetic/Ultrasonic Energy Field Cast-Rolling On Microstructure And Properties Of AZ31B Magnesium Alloy Sheet

Magnesium alloy has low density, high specific strength and stiffness, good electromagnetic shielding performance, easy recovery and so on, in recent years, it has been used in the automotive, aerospace and military industry and other fields, and it becomes the important structural engineering materials after the steel, aluminum and copper. Magnesium has only a slip plane, small independent slip system, poor plasticity at room temperature and difficulty deformation processing. While the conventional ingot-hot rolling-warm rolling process for magnesium alloy plate has some insufficient, as high energy consumption, long production period, low yield and high processing cost, and it restricts its application seriously. According to this problem, some countries use continuous cast-rolling to replace the traditional method. This paper introduced the electromagnetic and ultrasonic field to the continuous cast-rolling process and realized the electromagnetic/ultrasonic cast-rolling expect to further improve the properties of cast-rolling magnesium plate.This paper established the cast-rolling model based on the ProCAST-CAFE module, and got the simulation microstructure results of ordinary and electromagnetic/ultrasonic cast-rolling magnesium plate, and discovering the phenomenon of the microstructure center stratified in the traditional cast-rolling plate.This paper did the sinking-mode asymmetric cast-rolling experiment according to the phenomenon of the microstructure center stratified in the simulation process and studied the microstructure and properties of electromagnetic/ultrasonic cast-rolling magnesium plate, and solved the microstructure defect of center stratified. The common plate dendrite cells developed, and the coarse grains, and average grain size is85～100μm. Electromagnetic/ultrasonic plate dendrite mass loss, and the nuclear proliferation, and average grain size is25～35μm. The average σb, σ0.2and extending rate values of electromagnetic/ultrasonic cast-rolling plate are253.8MPa,193.1MPa and4.3%, and rose respectively15.3%,24.9%and43.9%compared to the common plate.This paper studied the microstructure and properties of warm rolled after cast-rolling magnesium plate and the annealed magnesium plate, and discovering the recrystallization temperature of warn rolled after electromagnetic/ultrasonic plate as to the ordinary plate drops50℃to100℃, so the optimum annealing temperature of electromagnetic/ultrasonic plate is lower than the ordinary plate. Rolling temperature of300℃, the average σb,σ0.2and extending rate values of the electromagnetic/ultrasonic cast-rolling plate are289.7MPa,198.8MPa and7.4%, and rose respectively by12.8%,19.7%and127.8%as to the ordinary plate, and rose respectively by17.8%,4.1%and18.8%as to ingot-hot magnesium plate.