Formation of the Microstructure and Mechanical Properties of VT22 Titanium Alloy Under Nonequilibrium Conditions of Rapid Heat Treatment

We study specific features of the formation of microstructure and a complex of mechanical properties of VT22 high-strength titanium alloy in the process of rapid thermal treatment depending on conditions of cooling in the course of hardening. It is shown that the procedure of quenching in water guarantees better results of thermal hardening in the course of rapid thermal treatment due to the formation of a larger number of point defects and the decomposition of the metastable beta-phase during aging accompanied by the formation of intermediate omega- and alpha aEuro(3)(alpha')-phases. The main advantage of rapid heating over the heating in furnace is connected with the possibility of transformation of the entire volume of the alloy into the metastable beta-phase without catastrophic growth of grains. This enables one to significantly increase the strength of alloy (up to 1445 MPa) with preservation of sufficiently high levels of the characteristics of plasticity and impact toughness.