AZ31镁合金的热变形加工图及其应用

Hot deformation processing map of AZ31 magnesium alloy and its application

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.

To determine the deformation parameters of AZ31 magnesium alloy, the hot deformation behavior of the alloy was inves- tigated 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 12 s-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 50 s^-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.