Phase Transformation in Binary Titanium-Base Alloys with Metals of the I, IV−VIII Groups

Abstract

Martensitic β→α′(α″) transformation, β→ω transformation and eutectoid decomposition in a series of Ti-base alloys with d transition metals of Groups I, IV-VIII have been investigated using the techniques of X-ray diffraction, optical and transmission electron microscopy. Phase and structural information is given on the non-equilibrium and metastable modifications occurring in these alloys after quenching from high-temperature β-field and aging. The conditions of the orthorhombic α″-phase, ω-phase and metastable β-phase formation in binary titanium–base alloys with d-metals of V-VIII groups were investigated. It was established that the position of the alloying metal in the Periodic Table defines the presence or absence of the α″-phase in the alloy after quenching and the minimum concentration of the alloying metal necessary for formation of the α″-phase, ω-phase and metastable β-phase.