Oxidation of Al2O3-dispersion chromizing coating by pack-cementation at 800 °C

Preparation and oxidation of an Al2O3-dispersed chromizing coating were investigated by chromizing an as- electrodeposited Ni-Al2O3 nanocomposite film using a conventional pack-cementation method at a greatly decreased temperature (800 °C). For comparison, chromizing was also performed with the same condition on an as-deposited Ni film without Al2O3 nanoparticles. Oxidation at 900 °C indicates that, compared with the Al2O3-free chromizing coating, the Al2O3-dispersed chromizing coating exhibits a increased oxidation resistance, due to the formation of purer and denser chromia scale. The effect of Al2O3 on the coating formation and the coating oxidation behavior was discussed in details.