AA3003铸轧铝合金的等温析出动力学

Isothermal precipitation kinetics of AA3003 cast rolling aluminium alloy

在不同退火温度下研究AA3003铸轧铝合金的等温析出动力学,通过电导率的变化计算出该合金在不同退火时刻的析出分数,利用JMAK方程拟合并分析不同退火温度及冷轧变形量下的析出动力学;通过显微硬度和透射电镜的观察进一步研究析出与显微组织的关系。结果表明:扩散是析出过程的控制因素;冷轧变形会加快析出速率和降低鼻尖温度,但再结晶的发生削弱这种作用,并且再结晶使随后析出粒子形核的位置发生改变,导致JMAK模型中的反应级数n偏小。

The isothermal precipitation kinetics of AA3003 cast rolling aluminium alloy were investigated at different annealing temperatures. The precipitation fractions were calculated by conductivity changes, and the precipitation kinetics were fitted and analyzed by using the JMAK model at different temperatures and cold rolling reductions. The interactions between precipitation and microstructures were studied further by microhardness and transmission electron microscopy. The results show that the diffusion is the main governing factor of precipitation. The cold rolling enhances the rate of precipitation and lowers the nose temperatures, but the recrystallization weakens this effect and changes the nucleation sites of precipitates, which causes the reaction order n of JMAK model to slant small.