Microstructure evolution and static recrystallization during hot rolling and annealing of an equiaxed-structure TC21 titanium alloy

作者：Wang, Ke^*; Wu, Mingyu; Yan, Zhibing; Li, Dongrong; Xin, Renlong^*; Liu, Qing^*

来源：Journal of Alloys and Compounds, 2018, 752: 14-22.

DOI：10.1016/j.jallcom.2018.04.148

• Hot rolling
• Annealing
• Deformation mechanism
• Static recrystallization

An equiaxed-structure TC21 titanium alloy, consisting of predominant equiaxed alpha grains and remained beta phase, was hot rolled at 750 degrees C, and subsequently annealed at different temperatures. Based on electron back-scattered diffraction (EBSD) observation, the microstructure evolution and static recrystallization (SRX) during rolling and annealing were investigated. An apparent evolution of grain morphology occurred during rolling and annealing. The equiaxed a grain was elongated along the transverse direction (TD) during hot rolling, and then got an equiaxed morphology due to the SRX and boundary splitting during annealing. In contrast, subsequent annealing had a limited effect on the textures. The Kernel Average Misorientation (KAM) calculation showed that the beta phase endured a larger deformation amount than alpha phase, which induced a more preferential SRX in beta phase. Meanwhile, the different SRX mechanism between alpha and beta phases caused a different evolution of SRX and grain morphology with increasing annealing temperature. The continuous SRX (cSRX) in alpha phase made the SRX fraction increase and grain size decrease with increasing annealing temperature, with an exception of a grain growth at 940 degrees C. However, SRX occurred in beta phase by subgrain coalescence, which induced the increase of grain size and decrease of SRX fraction with increasing annealing temperature. Conclusively, 880 degrees C was an appropriate annealing temperature to get a uniform and refined microstructure for the hot-rolled TC21 titanium alloy.

• 出版日期2018-7-5
• 单位重庆大学