MECHANICAL BEHAVIOR AND MICROSTRUCTURE EVOLUTION OF Ti-6Al-4V WIRE ROD FOR PRODUCING AEROSPACE FASTENERS

The basic deformation parameters had a significant influence on the mechanical behaviour and microstructure evolution of a Ti-6Al-4V wire rod. Compression experiments were conducted to study the effect of the deformation temperatures (25-900 degrees C) and strain rates (0.1/s, 1/s and 10/s) on the mechanical behaviour and microstructure evolution. The microstructure observation and the quantitative metallographic of Ti-6Al-4V wire rod were investigated after the compression experiments. The results showed that the Ti-6Al-4V compressed samples tend to be cracked along a 45 degrees angle below 300 degrees C, which was regarded as the critical deformation temperature. Deformation temperatures from 400 degrees C to 600 degrees C can be regarded as the warm deformation region. Deformation temperatures from 700 degrees C to 900 degrees C can be regarded as the hot deformation region. And the softening mechanism was predominated by a temperature rise and dynamic recrystallization, respectively, for the warm deformation region and the hot deformation region of the Ti-6Al-4V alloy.