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利用Gleeble-1500热模拟试验机对7B50铝合金进行了变形温度300～460℃、应变速率0.001～1 s-1条件下的等温压缩试验,通过金相显微镜(OM)和透射电镜(TEM)等手段,研究分析了该合金在变形过程中热变形参数对微观组织的影响。结果表明:在变形初期,流变应力随应变的增加而增大,达到峰值后逐渐趋于平稳;应力峰值随温度的升高而减小,随应变速率的提高而增大;当变形温度较低或应变速率较高时,合金仅发生了动态回复,且合金组织中存在大量的位错和亚晶;随着温度的升高和应变速率的降低,合金中的主要软化机制由动态回复逐渐转变为动态再结晶。
7B50 aluminum alloy was subjected to isothermal compression test at deformation temperature of 300 ~ 460 ℃ and strain rate of 0.001 ~ 1 s-1 using Gleeble-1500 thermal simulation tester. The microstructure of 7B50 aluminum alloy was characterized by OM and TEM The influence of the thermal deformation parameters on the microstructure of the alloy during the deformation was studied. The results show that the flow stress increases with the increase of strain at the initial stage of deformation, and then gradually becomes steady after reaching the peak value. The peak value of stress decreases with the increase of temperature and increases with the increase of strain rate. Low or high strain rate, the alloy only dynamic recovery occurs, and there are a large number of dislocations and subgrains in the alloy; as the temperature increases and the strain rate decreases, the main softening mechanism in the alloy from the dynamic recovery gradually Change to dynamic recrystallization.