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RESEARCH PRODUCT

Mechanical, Kinetic and Morphological Correlations during the Scale Growth of Niobium and Zirconium Oxides

subject

description

Oxidation of niobium at 700°C and zirconium at 850°C, in air or oxygen pressures from 20 to I 000 hPa, lead to the formation in one case of a stratified Nb 2 O 5 oxide scale and in the other case a more compact ZrO 2 oxide scale. Analyses of the evolutions of phases, crystalline textures and mechanical stresses during oxidation are determined by X-ray diffraction techniques. Interactions between chemical processes, crystalline building and mechanical processes constitute together the driving force of the reaction and can explain the differences in morphologies of oxide scales.