Crystal Structure and Protium Absorption Properties of Ti-Cr-X Alloys

Abstract

This paper aims to develop the vanadium free Ti–Cr–X BCC solid solution alloys with high protium content. The effects of additional elements such as Mo, W, Nb and Ta to the phase formation on the Ti–Cr alloys were studied. It was found that Mo-added heat-treated alloys had the flattened plateau regions with the capacity of more than 2.2 mass% protium with maximum of 3.6 mass% protium content, which is equal to that of Ti–Cr–V alloys. It was found that the Ti–Cr–Mo alloys with BCC structure transformed to protide phase with BCC or FCC structure. The plateau pressure of the Ti–Cr–Mo alloys increased with increasing Mo content, but the lattice parameters decreased. The H/M ratio of the alloy with less than 10 at%Mo was 1.8 at 10 MPa hydrogen pressure and was almost unchanged with Mo content.