Effects of compositions on formation of 1, 2 protorides in Ti-Cr-V alloys

Abstract

Ti-Cr-V alloys are known to absorb protium up to H/M = 2. However, Ti-Cr-20 at%V alloys with more than 56 at%Cr content were found to absorb up to H/M = 1. This paper aims to make clear the effects of compositions on formations of 1, 2 protorides in Ti-Cr-V alloys, and the structure of the mono-protorides. It was found that the mono-protorides with fcc and hcp structures exist. The mono-protoride with the fcc structure was different from the di-protoride with the FCC structure in the lattice constants. Some relationship between appearance of the mono-protorides and disappearance of the plateau regions in low hydrogen pressure regions was considered to exist. As a result, the appearance regions of 1, 2 protorides in Ti-Cr-V alloys were derived.