Effect of hydrogen on phase and structural transformations in titanium alloys of different classes

We study the laws of phase and structural transformations in titanium alloys under the action of dissolved hydrogen and in the course of subsequent degassing. We show the possibility to control structure formation in them with the help of alloying with hydrogen and to obtain structures that cannot be obtained by conventional technological methods. It has been established that the alloying system determines the character of interaction of these alloys with hydrogen in the course of hydrogenation. After additional alloying with hydrogen, intermediate hydrides are formed in titanium alloys with β-isomorphic stabilizers (V, Nb), Ti Cr₂ intermetallic compound appears in alloys with β-eutectoid stabilizer (Cr), and Ti₃Al compound is formed in alloys with high aluminum content. After vacuum annealing of hydrogen-containing specimens at 600°C, a composite heterophase (α + β + α₂) or (α + β + TiCr₂) structure is formed, and intermetallic particles in it have an incoherent boundary. __________ Translated from Fizyko-Khimichna Mekhanika Materialiv, Vol. 42, No. 3, pp. 33–39, May–June, 2006.