Thermal Stability of Nanosized Nonmetallic Phase Particles in Low-Activated Dispersion Hardening Vanadium Alloys

The results of experimental and theoretical investigations of the thermal stability of heterophase structure of low-activated vanadium alloys with various types of nonmetallic phases (TiC, ZrC, and ZrO2) in the temperature‒time intervals of their technological treatment and operation in the core of nuclear and thermonuclear reactors are presented. It is shown that the thermal stability of these phases is determined by their thermodynamic stability and coagulation rates, which are responsible for the thermal stability of the nanosized heterophase structure. An important factor controlling these rates is the ratio between the standard thermodynamic potentials of their formation and the corresponding potentials of vanadium carbides and oxides. An assumption is made about the possibility of increasing the thermal stability of the heterophase structure of V–ZrC alloys by 100–200 K compared to V–TiC alloys and by 200–300 K in V–ZrO2 compositions.