The mechanism for self-formation of a CeO2 diffusion barrier layer in an aluminide coating at high temperature

A CeO2 dispersed δ-Ni2Al3 was formed by partially aluminizing an electrodeposited Ni film containing CeO2. The aluminide/Ni-CeO2 coating system itself quickly formed a CeO2-rich diffusion barrier between aluminide and Ni during annealing in vacuum at 1000 °C. A model for the formation of the diffusion barrier was proposed, based on the characterization of the evolution with time of the phase compositions of the aluminide at the interface.