EFFECT OF HYDROGEN ON HIGH TEMPERATURE PLASTICITY OF Ti-6Al-4V ALLOY

The effects of various hydrogen contents on the flow stress(σ),strain rate sensitivity expo-nent(m)and the tensile elongation(δ)of Ti-6Al-4V alloy were studied.Themicrostructure of the alloy was also investigated.The results indicate that,a suitable amountof hydrogen in the alloy can reduce the flow stress in the temperature range 800—860℃.Consequently,the superplastic temperature can be decreased and the ductility improved.