Thermal Stability of the Structure and Phase Composition of Titanium Treated with Compression Plasma Flows

The results of studying the structure and phase composition of the surface layer of commercial pure VT1-0 titanium treated with compression plasma flows in nitrogen atmosphere and annealed in the temperature range of 400–900°C for 1 h are presented. Using the X-ray diffraction method, the α-Ti(O) solid solution is found to form in the titanium surface layer at 500°C, without pretreatment with plasma, and to transform into the titanium oxide TiO₂ (rutile) phase at 600°C. Pretreatment of titanium with compression plasma flows promotes the formation of α-Ti(N) solid solution decreasing the rate of surface oxidation and increasing the initial temperature of rutile formation to 700°C, which indicates enhancement of the thermal stability of this structure.