AZ31镁合金的热变形加工图及其应用

为了确定AZ31镁合金轧制工艺参数,利用Gleeble--3500热模拟试验机进行热压缩试验以测试其热变形行为,并根据动态材料模型理论得到其热加工图.当变形温度为380～400℃、应变速率为3～12 s-1时,功率耗散效率大于30%,属于动态再结晶峰区;在该区域进行异步轧制变形退火处理后得到平均晶粒直径为2.3μm的细晶组织,抗拉强度为322.7MPa,延伸率为19.6%.当应变速率大于15 s-1时,属于流变失稳区,250～300℃低温加工时合金的塑性显著降低,350～400℃高温加工时合金出现混晶组织.

Hot deformation processing map of AZ31 magnesium alloy and its application

To determine the deformation parameters of AZ31 magnesium alloy,the hot deformation behavior of the alloy was investigated by hot compression testing on a Gleeble-3500 stimulator.The principle of dynamic material modeling was used to develop the hot processing map.There is a dynamic recrystallization peak zone in the processing map at temperatures from 380 to 400 ℃ and strain rates from 3 to 12s-1,and the efficiency of power dissipation is more than 30%.A fine equiaxed grain size of 2.3 μm could be achieved when differential speed rolling is processed in this region.The tensile strength is 322.7 MPa and the elongation is 19.6%.At strain rates of 15 to 50s-1,there are two flow instability zones: at temperatures of 250 to 300 ℃ the ductility of the alloy decreases obviously,but at temperatures of 350 to 400 ℃ the alloy has a mischcrystal structure.