中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 35 No. 7 July 2025 |
（1. State Key Laboratory of Materials Processing and Die & Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China;
2. China National Erzhong Group Deyang Wanhang Die Forging Co., Ltd., Deyang 618000, China）
Abstract:Hot compression experiments were conducted under conditions of deformation temperatures ranging from 950 to 1150 °C, strain rates of 0.001-10 s-1, and deformation degrees ranging from 20% to 80%. The hot deformation behavior and microstructure evolution of millimeter-grade coarse grains (MCGs) in the as-cast Ti-6Cr-5Mo-5V-4Al (Ti-6554) alloy were studied, and a hot processing map was established. Under compression along the rolling direction (RD), continuous dynamic recrystallization (CDRX) ensues due to the progressive rotation of subgrains within the MCGs. Along the transverse direction (TD), discontinuous dynamic recrystallization (DDRX) resulting from grain boundary bulging or bridging, occurs on the boundaries of the MCGs. With decreasing strain rate, increasing temperature, and higher deformation degree, dynamic recrystallization becomes more pronounced, resulting in a reduction in the original average grain size. The optimal processing parameters fall within a temperature range of 1050-1150 °C, a strain rate of 0.01 s-1, and a deformation degree between 40% and 60%.
Key words: as-cast Ti-6554 alloy; millimeter-grade coarse grains; deformation mechanism; hot processing parameters
