Ti-V-Cr b.c.c. alloys with high protium content

The effects of composition and heat-treatment on the protium absorption-desorption properties of Ti-V-Cr alloys were investigated. It was found that the Ti-35V-40Cr alloy shows a 2.6 mass% protium capacity. The plateau pressure of the Ti-35V-xCr alloys increased with decreasing lattice constants associated with increasing Cr content. The main phase of the as-cast Ti-xV-Cr (Cr/Ti=40/25) alloys containing more than 15%V was a b.c.c. phase. These b.c.c. alloys exhibited a 2.4 mass% protium capacity. Heat-treatment over 1673 K was effective on stabilizing the b.c.c. structure for the Ti-xV-Cr (Cr/Ti=2/3) alloys with low V content. The Ti-5V-57.5Cr alloy heat-treated at 1673 K for I h yields a high capacity of 2.8 mass% protium, which is the highest value at 313 K reported so far. The alloy is economically promising since it contains low amounts of expensive V metal. (C) 2002 Elsevier Science BY All rights reserved.