Formation of Linear Gradient Structures in Titanium Alloys Subjected to Hydrothermal Treatment

Structuring in hydrogen-alloyed VT22 titanium alloy subjected to vacuum annealing has been studied. It has been found that the alloy undergoes β → α transformation during low-temperature vacuum annealing, as a result of which the large-platelet structure changes to a dispersed one. The particle size of the resulting degassing-induced phase (α_deg) is no greater than 0.5 μm, and its hardness is 38 HRC. It has also been found that in the case of unidirectional hydrogenation with a barrier coating, the thickness of a layer with dispersed structure is 1.3 times greater than for omnidirectional hydrogenation without the coating with the temperature–rate conditions of the process being the same.