Abstract：The hot deformation behavior and microstructure evolution of 2055 Al-Li alloy have been investigated by subjecting the alloy to hot tensile tests carried out on Gleeble-1500 thermal simulator at the temperatures varied from 480-540 ℃ and strain rates 0.000 1-0.1 s-1. The microstructures of the alloy during deformation was studied by OM, TEM and EBSD. The results show that there are three stages in the hot stretching process and the deformation mechanism is different in each stage. In the process of hot stretching, it shows obvious rheological stability, the change from dynamic recovery to dynamic recrystallization is the main mechanism. When strain rate is 0.001 s-1 and deformation temperature is 480 ℃, the recrystallization nucleus are difficult observed. When the temperature are 510 ℃ and 540 ℃, serrated grain boundary appears. The higher the temperature is, the more obvious phenomenon of serrated grain boundary appears, which belongs to typical geometric dynamic recrystallization. At a certain temperature, the lower the strain rate is, the smaller the peak stress of the alloy is, which indicates that 2055 Al-Li alloy has the sensitivity of normal strain rate. The constitutive equation of hyperbolic sine function including deformation activation energy Q and temperature T proposed by Sellars and Tegart are used to describe the thermal activation behavior of the alloy. The activation energy of thermal deformation is 226.783 kJ/mol.
刘宁, 肖代红, 刘文胜. 2055铝锂合金热拉伸的显微组织与流变应力行为[J]. 粉末冶金材料科学与工程, 2020, 25(2): 125-132.
LIU Ning, XIAO Daihong, LIU Wensheng. Microstructure and flow stress behavior of 2055 Al-Li alloy under hot tension. Materials Science and Engineering of Powder Metallurgy, 2020, 25(2): 125-132.
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2020, Vol. 25 
