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在Gleeble-3500热模拟机上对半固态7050铝合金进行了高温热压缩试验,研究了该合金在变形温度为420～465℃、应变速率为0.001～0.100s-1条件下的流变应力行为以及变形过程中的显微组织。结果表明,流变应力在变形初期随着应变的增大迅速增大,出现峰值应力后逐渐平稳,流变应力随着应变速率的增大而增大,随着变形温度的升高而下降;流变应力可以用双曲线正弦形式的关系来描述,通过线性拟合计算出该材料的形变激活能等参数,获得流变应力的本构方程。随着变形温度升高和应变速率降低,合金中拉长的晶粒变大,合金热压缩变形的主要软化机制为动态再结晶。
The high temperature thermal compression test of semi-solid 7050 aluminum alloy was carried out on a Gleeble-3500 thermal simulator. The flow stress behavior of the alloy at deformation temperature of 420 ~ 465 ℃ and strain rate of 0.001 ~ 0.100s-1 was studied. Deformation of the microstructure. The results show that the flow stress increases rapidly with the increase of strain at the initial stage of deformation, and gradually becomes steady after the peak stress. The flow stress increases with the increase of strain rate and decreases with the increase of deformation temperature. The rheological stress can be described by the hyperbolic sine relationship. Parameters such as the deformation activation energy of the material are calculated by linear fitting to obtain the constitutive equation of flow stress. As the deformation temperature increases and the strain rate decreases, the elongated grains in the alloy become larger and the main softening mechanism of the hot compression deformation of the alloy is dynamic recrystallization.