Correlations between Growth Kinetics and Microstructure for Scales Formed by High-Temperature Oxidation of Pure Nickel. II. Growth Kinetics

Raphaëlle Peraldi (1) , Daniel Monceau (1) , Bernard Pieraggi (1)

1 CIRIMAT - Centre interuniversitaire de recherche et d'ingenierie des matériaux

The oxidation kinetics of high-purity nickel were studied between 500 and 1200°C, in pure oxygen at atmospheric pressure, for aûerage oxide-scale thicknesses of 1, 5, 10, and 30 μm. In the oûerall temperature range studied, a decrease in the parabolic rate constant kp with increasing scale thickness was observed. Depending on temperature and oxide-scale thickness, growth kinetics can be interpreted as a mixture of parabolic- and cubic-growth kinetics. Possible correlations between growth kinetics and microstructures of the oxide scales were inûestigated. From this set of experimental data, oxidation-kinetics models were tested. In particular, the effect of grain-boundary diffusion on NiO-growth kinetics was discussed. The correlations between growth kinetics and oxide microstructures appear to be more complex than usually reported.

Mots clés: Ni oxidation; Growth kinetics; Kp; Grain-boundary diffusion

Domaines: Matériaux

Raphaëlle Peraldi, Daniel Monceau, Bernard Pieraggi. Correlations between Growth Kinetics and Microstructure for Scales Formed by High-Temperature Oxidation of Pure Nickel. II. Growth Kinetics. Oxidation of Metals, 2002, 58, pp.275-295. ⟨10.1023/A:1020102604090⟩. ⟨hal-03604509⟩