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 under hydrogen pressure of 1.0 MPa. The thermodynamic possibility 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, XRD 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 (TiCuH_1,19, Ti₃Cu₄H_2,44, Ti₂Cu₃H_1,32) and their decomposition to titanium and copper hydrides. The rate of formation of these hydrides is higher than the rate of their decomposition. It is established that mechanical destruction of the material occurs during direct hydrogenation.