1420铝锂合金的温压变形及动态再结晶行为

Dynamic recrystallization mechanism during warm deformation in 1420 alloy

采用金相、扫描电镜及背反射电子衍射等检测手段,对1420铝锂合金在温压变形时不同变形量的微观组织与织构进行研究。结果表明:在350℃及较高的应变速率.ε=6.93 s-1的变形条件下,1420铝锂合金在变形量为90%时出现粒径d<5μm的大量细晶组织,发生了动态再结晶;立方取向晶粒的形核与长大均不占优势,再结晶晶粒表现为强烈的形变取向。为此,提出了一种新的粒子激发形核与亚晶倾转形核长大的混合再结晶模式。

The microstructures and microtexture of 1420 Al-Li alloy at different stages during warm deformation were investigated by metallography, scanning electron microscopy and electron backscattering diffusion. The results indicate that dynamic recrystallization occurs in the 1420 Al- Li alloy at lower temperature of 350℃ and higher strain rate of 6.93 s^-1, leading to a uniform fine microstructure with d〈5μm at ε=90%, and that the cube orientation nucleus does not have superiority in nucleation and growth. Moreover, the final recrystallized grains show typical deformation orientation distribution. A new dynamic recrystallization model consisting of particlestimulated nucleation and sub-grain rotated-induced nucleation was proposed.