Investigation on the effect of electroshock treatment on the microstructure and mechanical properties of Ti–45Al–5Nb alloy

Abstract

This study investigated the effects of electroshock treatment (EST) on the microstructure and mechanical properties of Ti–45Al–5Nb alloy. Microstructure results showed that no new phase was generated after EST, the peak positions of α2 phase and γ phase were shifted, the relative intensity of the diffraction peaks were enhanced, and the grain orientations were varied. The original relatively coarse α2 lamellae decomposed into fine γ+α2 lamellae in a direction parallel to the original γ/α2 lamellae. The segregation of Nb element was weakened and the distribution was more uniform. Texture research showed that after EST with 60 ms and 80 ms, the maximum relative texture intensity of γ phase was enhanced. After EST with 100 ms, the maximum relative texture intensity of γ phase weakened to 17.86, and the grain orientation became dispersed. The texture distribution was more uniform. The maximum relative texture intensity of α2 phase was weakened and the orientation was dispersed after EST. Mechanical property results showed that after EST, the yield strength and fracture strain of the material was improved. The main reason is that the precipitation of γ phase forms fine γ/α2 lamellae. All results indicate that EST provides a new way to manipulate the microstructure and properties of TiAl alloys.