Micro-crystalline Fe–Cr–Ni–Al–Y2O3 ODS alloy coatings produced by high frequency electric-spark deposition

Fe–Cr–Ni–Al–Y2O3 oxide dispersion strengthened (ODS) alloy coatings were deposited on the surface of 1Cr18Ni9Ti stainless steel by using high-frequency electric-spark technique. The composition of these ODS coatings was determined by the interaction between the electrode material MA956 ODS alloy and the substrate alloy. These ODS coatings possess micro- or nano-crystalline structure with metallurgical bonding to the substrates. The microstructures of the dispersed oxide particles were observed by TEM. High-temperature oxidation was performed in air at 1000 °C. Results indicated that the selective oxidation of Cr was greatly promoted and the scale spallation resistance was significantly improved. The synergistic effects of micro-crystallization and dispersed Y2O3 particles on the oxidation behaviors have been discussed.