A Novel Thermic Process for Producing V-Based Solid Solution Type Hydrogen Storage Alloy

Abstract

The performance of a high hydrogen capacity alloy, V-16%Ti-12%Ni-1.4%Nb-0.96%Co-2.8%Ta, is sensitively influenced by dissolved aluminum and oxygen, both of which can be removed from vanadium by a refining process, but the process currently used is too expensive. It is necessary to develop a process to remove these impurities at a reasonable cost. We propose a new method for production of the alloy. A V-15%Ni-1.8%Nb precursor with a low enough level of aluminum was produced by alumino-thermic reduction from a mixture of V 2 O 5 , Nb 2 O 5 and nickel. Subsequently, a V-16%Ti-12%Ni-1.4%Nb-0.96%Co-2.8%Ta alloy was obtained by alloying the precursor and the other constituents of titanium, cobalt and tantalum, and by adding mischmetal as a reducing agent to remove oxygen to a low enough level. It was demonstrated that, by the method described here, the vanadium-based alloy could be produced at a reasonable cost.