退火过程中AA3003铝合金的析出与再结晶

Precipitation and recrystallization of AA3003 aluminium alloy during annealing

通过硬度测试、电阻测试以及光学显微镜观察,研究不同冷变形量的AA3003合金在退火过程中析出与再结晶的相互作用及其对显微组织的影响。研究结果表明:在300℃和500℃退火时均有大量第二相粒子析出;在300℃退火时,析出相优先在位错、亚晶界等点阵缺陷处形核,较大的冷轧变形量将导致更多的析出;而且在300℃退火时,析出发生在再结晶之前,导致再结晶晶粒粗大;而在500℃退火时,再结晶发生在析出之前,析出与冷轧变形量无关,并可获得晶粒细小的再结晶组织。

The interaction of recrystallization and precipitation of AA3003 aluminum alloy during annealing as well as its effect on the microstructures of alloys were investigated by means of hardness, electrical resistivity measurements and optical microscopy. The results show that a large number of precipitates occur during annealing at 300 ℃ and 500 ℃. Annealing at 300 ℃, the precipitates are nucleated preferentially at lattice defects, such as dislocations and sub-boundaries, higher cold reduction results in a larger number of precipitates. Annealing at 300 ℃, the precipitation occurs prior to recrystallization, and the grains become coarse. However, annealing at 500 ℃, the recrystallization happens prior to precipitation, the precipitation is independent of the cold deformation reduction and a fine, equiaxed grain structure is obtained.