|About this Abstract
||2018 TMS Annual Meeting & Exhibition
||Ultrafine-grained Materials X
||Micro-mechanical Response of Gamma-based TiAl Intermetallic Compound Processed by High-pressure Torsion
||Megumi Kawasaki, Jae-Kyung Han, Xi Li, Rian Dippenaar, Klaus-Dieter Liss
|On-Site Speaker (Planned)
The present study applies a strategy of grain refinement on a γ-based Ti-45Al-7.5Nb intermetallic compound through high-pressure torsion (HPT) for 5 and 10 turns under 6.0 GPa at room temperature. The duplex microstructure was successfully refined to have ultrafine laths with thicknesses of 40-100 nm after 10 HPT turns. Exceptional hardness is recorded by both Vickers microhardness and nanoindentation measurements. The X-ray diffraction profiles confirmed the occurrence of phase transformation from γ-TiAl to α2-Ti3Al in the alloy. Macroscopic plastic flow is estimated for the γ-TiAl based alloy through the nanoindentation technique with applying two different indenters. The results predict a significant change in plastic behavior by increasing the strain rate sensitivity and in yield strength after microstructural refinement whereas the strain hardening capability decreases in the TiAl alloy after HPT for 10 turns. This study demonstrates the promising feasibility of HPT processing for improving essential mechanical properties in the TiAl.
||Planned: Supplemental Proceedings volume