Effect Of Clock Rolling On Microstructures And Properties For AZ31 Magnesium Alloy Sheets

This paper develops a new rolling process of magnesium alloy sheets—clock rolling,which is favorable to control grain orientation of sheets mainly.Effects of clock rolling and heat treatment process on the evolution of microstructure and mechanical properties of AZ31 magnesium alloy shees were investigated.The main contents and results are as the following.①The anlysis on the microstructure of clock rolled AZ31 magnesium alloy sheetsThe evolution of microstructure and texture characteristic of AZ31 magnesium alloy sheets in the clock rolling process were studied.The results show that dynamic recrystallization occurs in the clock hot rolling process and much twin occurs in the clock cold rolling process;as a result of the frequent changes of rolling direction,the tensile direction,stress of grains and grains orientation distribution of clock rolled sheet are different from that of unidirectional rolled sheet serious.②The effects of annealing process on the microstructure and mechanical properties of clock rolled AZ31 magnesium alloy sheetsThe effects of annealing process on the microstructure and mechanical properties of clock rolled AZ31 magnesium alloy sheets were studied. The results show that the metallographic microstructures of clock hot rolled sheets are more uniform than that of unidirectional rolled sheets after annealing of 350℃*40min;the static recrystallization occurs after annealing of 200℃*0.5h;the microstructure uniformity of clock cold rolled sheets is better than that of unidirectional rolled sheets after annealing of high-temperature-long-time and the texture changes a bit after annealing;the vickers hardness of all sheets and decrease with increasing annealing temperature;the tensile strength and yield steength of clock hot rolled sheets are similar after various annealing process.③The anlysis of anisotropy on the clock rolled AZ31 magnesium alloy sheetsThe anisotropy of clock rolled sheets after various annealing process were studied. The clock hot rolled sheets show obvious anisotropy which is related to the distribution of texture.