铝合金半固态变形时的微观组织特征

文章在铝合金半固态压缩实验的基础上,深入研究了不同工艺参数下Al-4Cu-Mg合金半固态压缩时的微观组织形貌及参数变化。研究结果表明,半固态压缩时的微观组织特征受变形工艺参数的影响较大。变形程度越大,晶粒尺寸越小,晶粒圆整度越差。变形程度超过40%,晶粒尺寸急剧减小,变形机制发生了显著变化。随着应变速率的减小,晶粒尺寸增大,晶粒逐渐趋于圆整。在较高的变形温度下,晶粒发生了合并长大。但过高的变形温度引起晶粒尺寸的急剧增大,对变形不利。

Microstructural characteristic of Aluminium alloy in the semisolid state

Varieties in microstructural morphology and variables of Al-4Cu-Mg alloy have been investigated on the basis of semisolid compression.The experimental results show that the effect of process parameters on microstructural characteristic is obvious.The more height reduction is,the smaller grain is and the more unequiaxed grain become.Grains size decrease apparently and deformation mechanisms change when height reduction is above 40%.Grains coarsen and become more globular with a decrease of strain rate.Coalescence and coarsening of grains occur at high deformation temperature,which is unfavorable to deform because of grain coarsening resulted from higher deformation temperature.