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The thermodynamic possibility and conditions of Ti 2 Cu hydrogenation and recombination are assessed. The mechanism of Ti 2 Cu interaction with hydrogen between 293 and 973 K at pressure 1.0 MPa is studied. The interaction of Ti 2 Cu with hydrogen is thermodynamically possible in the destructive hydrogenation region over a wide temperature range. X-ray diffraction shows that destructive hydrogenation products are titanium dihydride and copper-rich intermetallic phases and copper depending on reaction conditions. According to the established mechanism of Ti 2 Cu destructive hydrogenation, hydrogen selectively interacts with titanium leaving Ti 2 Cu composition as follows: β-TiH y (bct-bcc) → TiH 1.92 (fcc). The initial Ti 2 Cu composition is recombined from destructive hydrogenation products (titanium dihydride and copper) in vacuum and hydrogen. The minimum temperature of Ti 2 Cu vacuum recombination is 1050 K and ensures complete TiH 2 decomposition. The recombination of Ti 2 Cu in hydrogen can occur at temperatures above 907 K.Compounds of titanium with copper are promising functional materials with high hardness, electrical and thermal conductivity, and satisfactory sound absorptivity. Coatings based on Ti-Cu intermetallides can greatly improve the sliding surfaces and tribotechnical properties in general. There are six intermetallic compounds known in the Ti-Cu system: Ti 2 Cu, TiCu, Ti 3 Cu 4 , Ti 2 Cu 3 , TiCu 2 , and β-TiCu 4 [1]. This paper considers the interaction of hydrogen with Ti 2 Cu, which has tetragonal crystal lattice of MoSi 2 type (structural group 17 4h D ) with parameters a = 0.2943 nm and c = 1.0784 nm [2].The interaction between Ti 2 Cu and hydrogen was earlier studied in [3][4][5][6][7], but none of the papers provided diffraction patterns of the reaction products. Nevertheless, it is stated in [3,4] that the reaction products are represented by titanium hydride and copper above 473 K and by direct hydride Ti 2 CuH 2.6 below 473 K [5, 6]. Padurets and colleagues [7] obtained TiCuH 2 and TiH 2 by Ti 2 Cu hydrogenation at 293-673 K and hydrogen pressure 0.1 MPa. The isothermal line of Ti 2 Cu-H equilibrium at 773 and 823 K was also studied [4]. Five pressure plateaus associated with heterophase composition of the system that interacts with hydrogen are revealed. Hence,

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