Nanocomposites and nanomaterials

Investigation of long-term oxidation resistance of titanium alloys with coating based on Ti-Al-C system nanocomposites
Podhurska V.Ya.1, Prikhna T.O.2, Ostash O.P.1, Vasyliv B.D.1, Sverdun V.B.2, Kuprin O.S.3, Serbeniuk T.B.2
1 Department of Hydrogen Technologies and Alternative Energy Materials, Karpenko Physico-Mechanical Institute of the NAS of Ukraine, 5 Naukova str., Lviv 79060, Ukraine.
E-mail: podhurskavika@gmail.com
2 Department of Sintering Technologies of Ceramics, Institute for Superhard Materials of the NAS of Ukraine, 2 Avtozavodska str., Kyiv 04074, Ukraine. 

3 Laboratory of Ion-Plasma Processing of Materials, National Science Center Kharkiv Institute of Physics and Technology, 1 Akademicheskaya str., Kharkiv 61108, Ukraine.

Physical and mechanical properties, the long-term (1000 hours) oxidation resistance at 600 °C in particular, for a number of titanium alloys and composites depending on their chemical and phase composition and production method have been studied. These materials are promising for gas microturbines of a hybrid system “solid oxide fuel cell – gas turbine”.
The oxidation resistance and electrical conductivity of a bulk composite based on MAX phase Ti2AlC, and Ti–Al–C vacuum arc-plasma coating on a thin (0.5 mm) titanium sheet in the initial state and after a long-term (1000 h) exposure in air at 600ºС have been studied. The evolution of the phase composition of the composite and Ti–Al–C coating under long-term exposure in an oxidizing environment and related with its oxidation resistance and electrical conductivity has been studied. 
It was shown that materials of the Ti–Al–X system (X = C, Nb, Mo) based on titanium MAX phases with nanolaminate microstructure have an advantage. At the same time, alloys based on titanium aluminides γ-TiAl / α2-Ti3Al in the cast state have the highest long-term oxidation resistance, as well as the best complex of physical and mechanical characteristics among the studied materials.