通过热模拟单拉试验,获得了AZ31镁合金板材在不同工艺条件下的真实应力应变曲线,分析了温度和应变速率对流变应力的影响.通过极限拉伸比试验,研究了轧制、退火、拉伸温度、拉伸速度、拉延间隙以及压边力等工艺因素对镁合金板材成形性能的影响.结果表明:交叉轧制和退火工艺能够显著提高镁合金板材的力学性能;在极限拉伸温度150℃、极限拉伸速度15 mm/s的工艺条件下,极限拉伸比能够达到3.0;AZ31镁合金板材适宜的拉延间隙为板厚的1.2倍.
The true strain-stress curves of AZ31 magnesium sheet were obtained by uniaxial tensile tests under different conditions, and the effects of forming temperature and speed were analyzed. Through the limiting drawing ratio tests, the influences of rolling, annealing, blank holder force, drawing gap, drawing temperature and speed on the forming performance were investigated. The experimental results show that the cross rolling and annealing can significantly improve the mechanical property of magnesium sheet metal; Under the technological condition of limit forming temperature 150 ℃ and limit drawing speed 15 mm/s, the limiting drawing ratio can reach 3.0; The proper drawing gap is 1.2 times the thickness of AZ31 magnesium sheet metal.