Quantitative Prediction of Voids Formation in a Growing Nickel Oxide Scale at 1373 K

Abstract

Voids which form in oxide scales strongly influence the mechanical properties of the scale and the adherence between the metal substrate and the scale. The purpose of this study is to demonstrate a method for quantitative estimation of voids formation in NiO scale, and compare the microstructure of the scale formed on nickel at 1373 K with the estimation.
Calculations of ion fluxes and their divergence in NiO scales can predict the annihilation of the oxides which mostly occurs in the vicinity of the metal/oxide interface and the volume fraction of the voids. These predictions are in good agreement with the observed morphology of NiO scale obtained in high temperature oxidation of nickel at 1373 K.