Deformed microstructure and texture of Ti6Al4V alloy
(State Key Laboratory of Solidification Processing, School of Materials Science and Engineering,
Northwestern Polytechnical University, Xi’an 710072, China)
Northwestern Polytechnical University, Xi’an 710072, China)
Abstract: Microstructure and texture evolution during hot compression of Ti6Al4V alloy with an initial equiaxed microstructure were studied in the temperature range of 850-930 °C, strain rate range of 0.01-1 s-1 and engineering compressive strain of 70%. The results indicate that when temperature is below 900 °C and strain rate is higher than 0.1 s-1, the microstructure is mainly composed of elongated α grains. While deforming at higher temperatures and lower strain rates, dynamic recrystallization takes place. Electron back scattered diffraction (EBSD) result shows that during dynamic recrystallization, subgrain boundaries absorb dislocations and the recrystallized grains with high angle grain boundary form. At 930 °C dynamic recrystallization has basically completed, and needlelike α phase forms after water quenching. Pole figure analysis indicates that compared with the initial specimen, textures below 930 °C are weaker, while at 930 °C they are stronger.
Key words: Ti6Al4V alloy; hot compression; dynamic recrystallization; EBSD; texture