Al-Mn-Mg-RE铝合金高温热压缩变形行为的研究B
Hot deformation behavior of Al-Mn-Mg-RE alloy during compression at elevated temperature
郭道强
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作者单位：郴州市强旺新金属材料有限公司
中文关键字：Al-Mn-Mg-RE合金；热变形；流变应力；组织结构
英文关键字：Al-Mn-Mg-RE alloy; Hot deformation; Flow stress; Microstructure
中文摘要：在Gleeble-1500热模拟机上对Al-Mn-Mg-RE合金进行等温热压缩实验，变形温度为300~500 ℃,应变速率为0.01~10 s-1。结果表明：Al-Mn-Mg-RE合金流变应力均随应变的增加而迅速增大至峰值，之后随应变的增加而呈不同程度的减小。峰值应力随着变形温度的升高和应变速率的降低而逐渐减小；可以采用Zener-Hollomon模型和温度补偿的应变速率因子Z参数值的双曲正弦模型来描述该合金热压缩变形流变应力行为，其热变形激活能为186.482 kJ/mol。在高Z值条件下变形组织是拉长晶的亚晶内存在大量位错，而低Z值条件是在已再结晶组织内形成了完整的亚晶结构。
英文摘要：The hot compression tests of Al-Mn-Mg-RE alloy were performed in the temperature range from 300 ℃ to 500 ℃ and at strain rate range from 0.01 s-1 to 10 s-1 on Gleeble-1500 system. The results show that the true stress-true strain curves exhibit a peak stress at a critical strain, after which the flow stresses decrease monotonically until high strains. The peak stresses decrease as deformation temperature increasing and strain rate decreasing, which can be represented by the Zener-Hollomon parameter Z in the hyperbolic-sine equation with the hot deformation activation energy of 186.482 kJ/mol. The deformed microstructures consist of a great amount of dislocations within subgrains in the elongated grains at high Z value, but exhibit well formed subgrains in the recrystalled grains at low Z value.