Oxidation Resistance of Nanocrystalline Microalloyed γ–TiAl Coatings under Isothermal Conditions and Thermal Fatigue

γ-titanium aluminide a promising structural material for automotive and aircraft applications at high temperatures suffers from poor gas corrosion resistance. It has been proved in this work by means of microthermogravimetry and SEM, EDS, EBSD and X-Ray diffraction carried out and under isothermal conditions and thermal cycling that a great improvement of the oxidation resistance of this material can be achieved due to magnetron sputtered coatings of γ-TiAl with vatious additions (Ag, Cr, Mo, Nb, Si or Ta) or their combinations. The oxidation rate of some of these coatings is four orders of magnitude smaller than that of the bare γ-TiAl substrate.