Effects of pressing temperature and initial microstructure on the equal channel angular pressing of Ti-6Al-4V alloy

Abstract

The effects of pressing temperature and initial microstructure on the equal channel angular (ECA) pressing of Ti-6Al-4V alloy were investigated in this study. The ECA pressing was carried out isothermally with route C at 500degreesC, 600degreesC and 700degreesC for two typical microstructures, i.e., the Widmanstatten microstructure and the equiaxed microstructure. The results showed that ECA pressing at 600degreesC and 700degreesC was successful without producing any noticeable segment at the specimen surfaces, while a large amount of surface segments were produced at 500degreesC. After I pass pressing at 600degreesC, the equiaxed microstructure showed more uniform material flow at the surface than the Widmanstatten microstructure. However, this microstructural influence was diminished with increase of the number of the ECA pressing. A flow-localization parameter that quantifies the flow non-uniform tendency in case of flow softening materials was used to explain the different results in each microstructure.