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This paper studied the effect of adding Ni/NiRe layer on the high temperature oxidation behavior of β-(Ni,Pt)Al coating. Cyclic oxidation test of β-(Ni,Pt)Al coating, 0Re-(Ni,Pt)Al coating and 1Re-(Ni,Pt)Al coating were investigated at 1150 ℃ in this paper. Results indicated that adding Ni in the coating signally relieved the internal oxidation and improved the adhesion of scale for 0Re-(Ni,Pt)Al coating. Doping Re further enhanced cyclic oxidation property of 1Re-(Ni,Pt)Al coating. Besides, the oxidation process of three coatings, the effect of Ni/Ni-Re layer on the spallation of oxide scale and the formation mechanism of big holes were discussed. • Adding Ni/Ni-Re reduced the oxidation rate and extent of β to γ′ phase degeneration. • The synergism effect of Pt/Re, lower Young's modulus and hardness jointly enhanced spallation resistance of oxide scale. • Fearful internal oxidation and wide spallation of scale was avoided due to the existence of pure Ni layer. • Big holes formed in 0Re-(Ni,Pt)Al coating due to the fast phase transform of β to γ′. [ABSTRACT FROM AUTHOR]

• The EBSD and TEM were used to study the microstructures of Re-doped β-NiAl coating. • Outer layer of Re-doped β-NiAl coating was composed of coarser β-NiAl grains and nanometer sized γ-Re precipitates. • Inner layer of Re-doped β-NiAl coating was consisted of tiny β-NiAl grains and submicron sized α-W phases. • γ-Re and α-W phases were distributed in both β-NiAl grain boundaries and different zones within the grains. To figure out the microstructure and precipitation phases of a Re doped β-NiAl coating, the electron backscatter diffraction (EBSD) and transmission electron microscopy (TEM) were both used. Re-doped β-NiAl coating was composed of outer coarser β-NiAl grains with nanometer sized γ-Re precipitates, inner tiny β-NiAl grains with submicron sized α-W phases and bottom interdiffusion zone (IDZ, consisted of strip TCP and β-NiAl phases). Moreover, these γ-Re and α-W nanoparticle phases were not only aggregated at β-NiAl grain boundary but also appeared within the grains. [ABSTRACT FROM AUTHOR]