Effect of multi-component doping on high temperature oxidation behavior of NiCoCrAlY argon atomized powder at 1200 ℃

NiCoCrAlYNbHfTa powders were prepared by using the argon gas atomization method through the composite modification of Nb, Hf and Ta elements. The oxidation performance of the prepared powders was compared with that of commercial NiCoCrAlY powder at 1200 ℃ for 24, 48 h and 72 h. The phase, microstructure, and elemental distribution of the powders were analyzed using X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive spectrometry (EDS). The isothermal oxidation experiments were conducted to compare the high-temperature oxidation performance of the two powders. The results indicate that the prepared powders have good sphericity, and the elemental distribution within the spheres is uniform. The NiCoCrAlYNbHfTa powders consist primarily of the β phase and the γ/γ' phases, and commercially available NiCoCrAlY powders are composed of the γ/γ' phase.NiCoCrAlYNbHfTa powder can rapidly form a dense oxide layer, effectively slowing the diffusion and consumption of Al. Conversely, commercial NiCoCrAlY powder consumes Al at a faster rate after isothermal oxidation. The two powders show similar overall trends in oxidation mass gain curves. However, commercial NiCoCrAlY powder has a longer initial oxidation period with rapid depletion of the Al element. In comparison with the commercial powder, the NiCoCrAlYNbHfTa powder exhibits superior high-temperature oxidation and anti-sintering performance.