2050铝锂合金热变形行为研究

Thermal deformation behavior of 2050 Al-Li alloy

利用热模拟压缩试验研究了变形温度300~540℃、应变速率0.01~10/s时2050铝锂合金的热变形行为,并通过光学显微镜(OM)、扫描电镜(SEM)和电子背散射衍射技术(EBSD)分析了合金热压缩态和固溶淬火态的组织演变规律。研究结果表明:2050铝锂合金流变应力随变形温度的升高而降低,随应变速率的提高而增大。合金在300~500℃区间呈现优异的热成型性,在500℃以上温度热压缩时试样表面逐步出现开裂。通过统计固溶淬火态组织的再结晶分数发现,在320~400℃热变形区间合金再结晶程度较高,达到80%;420℃再结晶分数为50%;440~520℃区间的再结晶分数低于10%。

The thermal deformation behavior of 2050 Al-Li alloy at the deformation temperature of 300~540℃and the strain rate of 0.01~10/s was investigated by thermal simulation compression test.The microstructure evolution of the alloy was analyzed by optical microscope(OM),scanning electron microscope(SEM)and electron backscattering diffraction(EBSD).The results show that the flow stress of 2050 Al-Li alloy decreases with the increase of deformation temperature and increases with the increase of strain rate.The alloy exhibits excellent thermal formability in the range of 300~500℃,and cracks gradually appear on the surface of the specimen when the hot compression temperature is higher than 500℃.According to the statistics of the recrystallization fraction of the quenched microstructure,the recrystallization degree of the alloy at 320~400℃is as high as 80%.The recrystallization fraction is 50%at 420℃.The recrystallization fraction between 440℃and 520℃is less than 10%.