Theoretical Evaluation of Strengthening Ability of Phase Interfaces in Lamellar Ti Alloys

Abstract

Strengthening abilities (Hall–Petch coefficients) and the barrier strength of α/β lamellar interfaces and coarse primary/fine secondary α lamellae interfaces in Ti alloys are theoretically estimated based on the lattice and modulus mismatches of two phases on both sides of the interfaces. The results reveal that the strengthening abilities of the α/β lamellar interfaces and the coarse primary/fine secondary α lamellae interfaces are about 272.6 and 68.9 MPa, respectively, and the interface barrier strength of the α/β lamellar interface is about 9.5 times higher than that of the coarse primary/fine secondary α lamellae interface. The variation trend of the interface strengthening abilities with the fraction of α/β interfaces for lamellar Ti alloys is found. The finding may provide a potential strategy for enhancing the strength or deformability of lamellar Ti alloys through manipulating interface properties.