Effect of different fillers on oxidation behavior of low-temperature chromizing coating

Three different chromizing coatings were produced on Ni substrate using a conventional pack-cementation method with Al2O3, Al2O3+CeO2 and CeO2 acting as filler, respectively, at a greatly decreased temperature (700 °C). Effects of different fillers on the isothermal and cyclic oxidation resistance of chromizing coating in air at 850 °C were comparably investigated. Microstructure results show that the addition of CeO2 into the filler significantly retards the grain growth of the chromizing coating. Oxidation results indicate that the chromizing coating using CeO2 as filler exhibits somewhat increased oxidation resistance than the normal chromizing coating, while the chromizing coating using Al2O3+CeO2 as filler exhibits much better oxidation resistance. The effects of different fillers on the oxidation behaviors were discussed in detail.