Hot deformation behavior of TiAl-V-Cr alloy near-α phase region

doi:10.13251/j.issn.0254-6051.2025.01.008

Abstract

Abstract: Hot deformation behavior and microstructure evolution of Ti-44Al-5V-1Cr alloy deformed near the α-phase region (at 1250 ℃) under different conditions as various initial microstructure, strain rates and deformation were investigated by means of thermophysical simulation, SEM, EBSD and OM characterization. The results show that when the deformation temperature is 1250 ℃, the difference of flow stress variations in initial microstructure of the alloy under identical deformation rate are smaller. However, under the same microstructural condition, the strain rate has a relatively significant effect on the flow stress. As the strain rate decreases, the flow stress decreases noticeably. When the alloy is deformed near the α-phase region, the dynamic recrystallization of α phase is dominant, and the dynamic recovery is supplemented, while the β phase effectively suppresses the growth of α grains. In addition, increasing the deformation can facilitate the refinement of α grain size. After extrusion at 1250 ℃ with a high extrusion ratio, the alloy achieves a fine and uniform fully lamellar structure with average lamellar colony sizes of 12-23 μm.

Key words: TiAl alloy, near-α phase region, hot deformation behavior, microstructure

CLC Number:

TG139

Liu Hongwu, Gao Fan, Feng Xiangzheng, Li Zhenxi, Dai Songyan, Wang Qingfeng. Hot deformation behavior of TiAl-V-Cr alloy near-α phase region[J]. Heat Treatment of Metals, 2025, 50(1): 53-57.

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