TY - JOUR
T1 - High-temperature “Inverse” Hall-Petch relationship and fracture behavior of TA15 alloy
AU - Li, Shaolong
AU - Li, Shufeng
AU - Liu, Lei
AU - Liu, Huiying
AU - Wang, Chuanyun
AU - Withers, Philip J.
AU - Zhu, Yuntian
AU - Gao, Lina
AU - Wang, Shaodi
AU - Chen, Biao
AU - Huo, Wangtu
AU - Gao, Jianbo
AU - Zhang, Xin
AU - Li, Bo
N1 - Publisher Copyright:
© 2024 Elsevier Ltd
PY - 2024/5
Y1 - 2024/5
N2 - The Hall-Petch relationship is important for material design at room temperature. However, it is not well studied at high temperatures. In this work, the influence of different microstructures on the high-temperature mechanical behavior and corresponding softening mechanisms of high-temperature titanium alloy TA15 (Ti-6.5Al-2Zr-1Mo-1 V, wt.%) were studied. Specimens with duplex, Widmanstätten, and coarse Widmanstätten microstructures were obtained through powder metallurgy. High-temperature tensile tests were carried out between 500 and 650°C. It was found that the fracture mode of the Widmanstätten microstructure was transgranular at 500 °C and 550 °C, but intergranular at 600 °C and 650 °C. EBSD analysis revealed that the high-temperature deformation was facilitated by several mechanisms including GB softening, GB migration, grains rotation, and activation of multiple slip systems. High temperature nanoindentation indicated sofenting of individual grains with increasing temperature. In-situ tensile testing under SEM revealed deformation was primarily in grain interior at room temperature, and GBs played a significant role at 650℃. The GB behavior at high temperatures is believed responsible for the inverse Hall-Petch relationship. These findings provide a new perspective for improving the high-temperature mechanical properties and microstructure control of titanium and its alloys.
AB - The Hall-Petch relationship is important for material design at room temperature. However, it is not well studied at high temperatures. In this work, the influence of different microstructures on the high-temperature mechanical behavior and corresponding softening mechanisms of high-temperature titanium alloy TA15 (Ti-6.5Al-2Zr-1Mo-1 V, wt.%) were studied. Specimens with duplex, Widmanstätten, and coarse Widmanstätten microstructures were obtained through powder metallurgy. High-temperature tensile tests were carried out between 500 and 650°C. It was found that the fracture mode of the Widmanstätten microstructure was transgranular at 500 °C and 550 °C, but intergranular at 600 °C and 650 °C. EBSD analysis revealed that the high-temperature deformation was facilitated by several mechanisms including GB softening, GB migration, grains rotation, and activation of multiple slip systems. High temperature nanoindentation indicated sofenting of individual grains with increasing temperature. In-situ tensile testing under SEM revealed deformation was primarily in grain interior at room temperature, and GBs played a significant role at 650℃. The GB behavior at high temperatures is believed responsible for the inverse Hall-Petch relationship. These findings provide a new perspective for improving the high-temperature mechanical properties and microstructure control of titanium and its alloys.
KW - Grain-boundary strength
KW - High-temperature softening mechanism
KW - High-temperature “Inverse” Hall-Petch
KW - TA15 alloy
UR - http://www.scopus.com/inward/record.url?scp=85189681490&partnerID=8YFLogxK
U2 - 10.1016/j.ijplas.2024.103951
DO - 10.1016/j.ijplas.2024.103951
M3 - 文章
AN - SCOPUS:85189681490
SN - 0749-6419
VL - 176
JO - International Journal of Plasticity
JF - International Journal of Plasticity
M1 - 103951
ER -