Oxidation behaviour of micro-crystalline Ni–20Cr–Y2O3 ODS alloy coatings

Abstract Ni–20Cr–Y2O3 oxide dispersion strengthened (ODS) alloy coatings were deposited on the surface of Ni–20Cr alloy by a special electro-spark technique. Two methods were used to prepare these ODS alloy coatings: (a) using M754 ODS alloy as the electrode; and (b) using M754 electrode with nano-particles of Y2O3 on the surface of substrates. The ODS coatings possess micro-crystalline structure and metallurgical bonding with the substrates. The experimental results of high-temperature oxidation in air at 1000°C show that the formation of Cr2O3 scale has been promoted on these coatings with excellent scale spallation resistance. The mechanisms of the beneficial effects of these coatings were also discussed.