Effect of hydrogen on microstructure evolution and deformation behaviors of Ti-2Fe-0.1B alloy

A low-cost Ti-2Fe-0.1B alloy with high performance was manufactured and hydrogenated in this study. The effect of 0.3 wt% hydrogen addition on microstructure evolution, compression deformation behavior at room and high temperature of Ti–2Fe–0.1B alloy has been investigated. Results indicated that lamellar α_L structure along with martensite α′ are formed after hydrogenation compared with initial equiaxed grains, and the fraction of β phase increased from 4.95% to 30.1%. Obvious phase transformation α_eq→α_H+ β_H, β→β_H during hydrogenation and β_H→α + δ, α_H→α + δ during subsequent cooling occurred. The hydrogenated Ti-2Fe-0.1B alloy is characterized by hardening effect during compression deformation at room temperature along with the loss of ductility due to the solid solution strengthening by hydrogen atoms and presence of hydride δ. However, peak flow stress of hydrogenated Ti-2Fe-0.1B alloy decreased from 49 MPa to 29 MPa extremely during compression deformation at 973 K, which can be attributed to the high volume of β phase induced by hydrogenation, as well as the promotion of dynamic recovery and dynamic recrystallization.