Structural and phase mechanism and rate of interaction between TiCu, Ti3Cu4, and Ti2Cu3 intermetallic compounds and hydrogen. I. Formation and decomposition of intermetallic hydrides

Abstract

The paper examines the phase mechanism and rates of TiCu, Ti3Cu4, and Ti2Cu3 interaction with hydrogen in the range 298–573 K at a hydrogen pressure of 1.0 MPa. The thermodynamic potential of TiCu direct and destructive hydrogenation and TiCu decomposition is established. The thermodynamic priority of destructive hydrogenation in the range 298–773 K is revealed. However, x-ray diffraction shows that only direct hydrogenation of TiCu, Ti3Cu4, and Ti2Cu3 proceeds in the range 298–373 K. The intermetallic compounds successively interact at 573 K with hydrogen through the formation of intermetallic hydrides (TiCuH1.19, Ti3Cu4H2.44, and Ti2Cu3H1.32) and their decomposition to titanium hydride and copper. These hydrides form more rapidly than decompose. It is established that mechanical destruction of the material occurs during direct hydrogenation.