Tuning the microstructure and mechanical properties of TiAl-based alloy through grain boundary engineering

In order to modify the room-temperature plasticity of TiAl-based alloy, grain boundary character distribution (GBCD) in TiAl-based alloy was tuned through multidirectional isothermal forging (MDIF) combined with annealing. The experimental results showed that MDIF provided appropriate driving force for the regeneration of the coincidence site lattice (CSL) boundaries through recovery and recrystallization process. Combination of MDIF and annealing at 1100 degrees C for 90 min promoted the formation of a large number of annealing twins and increased the fraction of low-SCSL boundaries to 65.88% and the ratio of (Sigma 9+Sigma 27)/Sigma 3 to 15.12%, which contributed to the disruption of random boundary networks and enhanced the room-temperature plasticity of the TiAl-based alloy. (C) 2022 The Author(s). Published by Elsevier B.V.

Automated summary

Grain boundary character distribution (GBCD) in TiAl-based alloy was modified through multidirectional isothermal forging (MDIF) combined with annealing, resulting in enhanced room-temperature plasticity. The combination of MDIF and annealing at 1100 degrees C for 90 min promoted the formation of annealing twins and increased the fraction of low-SCSL boundaries, leading to the disruption of random boundary networks and improved plasticity in TiAl-based alloy.