TY - GEN A1 - Liu, Xu A1 - Song, Lin A1 - Stark, Andreas A1 - Lorenz, Uwe A1 - He, Zhanbing A1 - Lin, Junpin A1 - Pyczak, Florian A1 - Zhang, Tiebang T1 - Deformation and phase transformation behaviors of a high Nb-containing TiAl alloy compressed at intermediate temperatures T2 - Journal of Materials Science and Technology N2 - In modern β-solidified TiAl alloys, the decomposition of α2 phase is frequently observed during heat treatment or high-temperature deformation of the alloys. In this study, high-temperature deformation and decomposition mechanisms of α2 phase in a Ti-45Al-8.5Nb-0.2B-0.2W-0.02Y alloy are investigated. In a sample deformed at 800 °C, the precipitation of βo(ωo) phase is observed within the equiaxed α2 phase. The nucleation of ωo particles within the βo matrix indicates the α2→βo→ωo transformation. In addition, numerous γ phase precipitates form within the βo(ω) areas. The α2 lamellae decompose into ultrafine (α2+γ) lamellae and coarsened γ lamellae via α2→α2+γ and α2→γ transformation, respectively. Moreover, the ωo phase nucleates within the ultrafine lamellae via α2→ωo transformation. However, in a sample deformed at 1000 °C, the nucleation of βo particles is sluggish, which is caused by the efficient release of the internal stress via dynamic recrystallization (DRX). These results indicate that complex phase transformations can be introduced by the decomposition of α2 phase in TiAl alloys with a high amount of β-stabilizing elements. Y1 - 2023 UR - https://opus4.kobv.de/opus4-UBICO/frontdoor/index/index/docId/30284 SN - 0861-9786 VL - 102 SP - 89 EP - 96 ER -