Effect Of Different Rolling Processes On Microstructure And Properties For AZ31Magnesium Alloy Sheets

In this paper, the rolling experiments of AZ31magnesium alloy by differentrolling processes were conducted. Moreover, the finally rolled sheets were annealedby different annealing processes. So systematic research was launched, which wasabout the effect of different rolling and annealing processes on the microstructure,texture and mechanical property of these sheets. The rolling process conditionincluded rolling ways that were consisted of unidirectional rolling (UR) and clockrolling (CR), rolling reduction per pass (r.p.p) and annealing frequency duringrolling. The research results are as follows:For the rolled AZ31magnesium alloy cast ingots, there were a lot of slicedynamic recrystallized (DRXed) compression or secondary twins during rolling. Atthe same time, the dynamic recrystallization barely happened in the tensile twins thatwere looked like thick lens. The amount of shear band increased rapidly with theincreasing of reduction per pass (r.p.p). The quite different microstructuredistribution could be caused by different rolling ways. The clock rolling could makethe microstructure and basal texture distribution more uniform than that of theunidirectionally rolled one.The shear band, which had different distribution along different deformationdirection of sheet, was apt to be the area that supported crack formation and spread.Therefore, the elongation difference between the0°and90°direction of rolled sheetsincreased with the shear band amount and basal texture intensity increase. The clockrolling could promote the mechanical property isotropy for the rolled AZ31magnesium alloy sheets.The mean grain size of the CRed sheets was always bigger than that of URedsheets during annealing. The variation trend of mean grain size at450℃was slightlyaccelerated than that at400℃. But the grains could grow rapidly in a very short timeat520℃. For the mentioned three annealing temperatures, all the sheets had almostsame variation trend of basal texture intensity, but there was a variation rangedifference among them.