AZ31镁合金板材复合形变的孪晶组织及晶粒尺寸

Twins and Grain Size of AZ31 Magnesium Alloy Sheet by Compound Deformation

研究了复合形变对镁合金AZ31板材性能的影响规律,比较了不同变形齿间比、温度和压下量对镁合金板材微观组织的影响。研究结果表明,在复合变形条件下,随着齿间比的增大,板材孪晶体积分数逐渐减小,平均晶粒尺寸有先减小后增大的趋势。随着压下量的逐渐增大,板材的孪晶体积分数逐渐增大,平均晶粒尺寸也有先减小后增大的趋势。同时过大的压下量容易导致板材断裂。随着变形温度的提高,板材能完成较大的变形量,但是孪晶体积分数逐渐减少,晶粒尺寸先减小后增大。

The law of performance of magnesium alloy AZ31 sheet attected by compound deformation had been researched. The effect of the different deformation ratio, temperature and reduction between teeth on the microstructure of magnesium alloy sheet was compared. The research results show that under the condition of compound deformation, the volume fraction of the twin crystal decreases gradually with the increasing of the tooth space ratio. The average grain size tends to decrease at first and then increase. With the increasing of rolling reduction, the volume fraction of the twin crystal gradually increases, and the average grain size also has a tendency to decrease first and then increase. Excessive reduction will fracture the sheet easily. With the increasing of deformation temperature, the greater deform- ation degree of sheet had obtained, while the volume fraction of the twin crystal decreases gradually, but the grain size of twin crystal decreases first and then increases.