The role of microstructure in the mechanical behaviour of Ti–1.6 wt.%Fe alloys containing O and N

The effects of small changes to the heat treatment temperature within the (α + β) phase field on the room temperature properties of a Ti–1.6 wt.%Fe–0.56 wt.%O–0.04 wt.%N alloy are described. To identify contributions from the individual alloying elements the binary Ti–1.6 wt.%Fe and ternary Ti–1.6 wt.%Fe–0.6 wt.%O and Ti–1.6 wt.%Fe–0.04 wt.%N alloys were also investigated. It was found that the interstitial elements affected the degree of disorder in the ωath phase, and that the magnitude of this disordering was not merely consistent with changes in Fe concentration. The strength and ductility of the alloys free of additional nitrogen were independent of annealing temperature, whereas the alloys containing nitrogen showed a marked dependency on the temperature. Alloys containing nitrogen displayed a prismatic rather than basal texture after processing.