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TiAl-based alloys have received extensive attention recently due to their excellent properties.However,the weak oxidation resistance at temperatures higher than 800 ℃ can limit their further high-temperature structural applications.To improve the oxidation resistance of a high-Nb-content y-TiAl alloy(Ti-45Al-8.5Nb,in units of at.％),a chromium(Cr)coating is prepared by using the plasma surface alloying technique,separately,at 800 ℃ and 1000 ℃.The x-ray diffraction(XRD)patterns reveal that an oxide surface layer consisting of Cr203,Al203,and TiO2 is produced on the Cr-coated Nb containing y-TiAl substrates during the initial oxidation.However,the Cr203 is dominated in the oxide surface layer after being isothermally oxidized for 300 h.The oxidation kinetic curves are composed of a parabolic law stage(≤ 90 h)and a biquadratic law stage(≥ 90 h),fit by weight-gain curves.Due to diffusion in the fabrication process and oxidation process,the Cr-coated specimens have an adhesion force after being isothermally oxidized,specifically 69 N for a specimen after oxidation for 300 h.These results demonstrate that the Cr coating enhances the oxidation resistance and adhesion of a Ti-45Al-8.5Nb alloy,which may provide a new feasible scheme for designing oxidation protection layers.