Formation of the structure of a laser–arc molten zone in VT22 titanium alloy

An investigation was made of structural and phase changes in the molten zone of a concentrated titanium alloy VT22 as a result of exposure to a laser–arc source and subsequent conventional annealing. Irreversibility of the changes was attributed to a redistribution of the alloying elements, particularly of molybdenum acting as the stabilizer of the β phase. An analysis of the results indicated the need to reduce the duration of action of the thermal source and to improve heat removal, and also to ensure multiple alloying of the molten zone (in a welding seam) with elements characterized by different distribution coefficients in order to reduce the degree of irreversibility of structural and phase changes and to improve the mechanical properties of welding seams.