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 10at%Mo was 1.8 at 10 MPa hydrogen pressure and was almost unchanged with Mo content.