Effect Of Caliber Rolling On Microstructure And Mechanical Properties Of AZ31 And ATZ341 Alloy

Magnesium alloy is one of the lightest structural metals at present,which can effectively reduce the weight of structural components.However,due to the limitation of strength,it cannot be widely used.Therefore,to improve the strength of magnesium alloy and optimize the processing technology of magnesium alloy is the top priority in the field of magnesium alloy research.In this paper,AZ31 and ATZ341 alloys were used for hot deformation processing of caliber rolling at 350 °C and 400 °C,respectively.The relationship between twinning behavior and dynamic recrystallization of AZ31 magnesium alloy and the relationship between precipitation mechanism and twinning behavior and dynamic recrystallization of ATZ341 magnesium alloy were explored by analyzing the microstructure and mechanical properties of the material after rolling.The results show that the formability of AZ31 magnesium alloy is better than that of ATZ341 magnesium alloy at the same temperature.The reason is that the precipitation pinning dislocation during rolling of ATZ341 magnesium alloy hinders the movement of dislocations and makes the plasticity worse.With the increase of rolling passes,the microstructure in the two materials gradually changes from original large grains to small grains,and the main transformation mechanism is DRX mechanism.In the initial pass,a large number of twins were generated within the original large grain composition of the material.The locations of DRX were mainly twin boundaries and twins,and the mechanism was twin-induced recrystallization.The static recrystallization grains of ATZ341 alloy show obvious abnormal growth,which is caused by the uneven distribution of the second phase during annealing.This proves that the precipitation and distribution of the second phase will directly affect the microstructure and properties of the alloy.The hardness and tensile properties of AZ31 alloy reached the best at the fourth pass of350 °C and the third pass of 400 °C.The hardness of ATZ341 alloy increases with the increase of pass caliber rolling at both temperatures,and the hardness of ATZ341 alloy is higher than that of AZ31 alloy at the same pass rolling temperature.This is due to the precipitation of the second phase in ATZ341 magnesium alloy during pass rolling,which plays a dispersion strengthening effect,and the strength of the alloy is further improved.This also provides some important theoretical accumulation for the study of high strength magnesium alloys.