High-Temperature Oxidation Properties of Al-Ion-Implanted Ni-Based Alloys

Abstract

The thermal oxidation properties of Al-ion-implanted Ni-based alloys used for thermocouples-such as Inconel 600, Alumel, Chromel and Constantan-were studied in humid O₂ atmospheres at 970K for 180ks. Ion implantation was performed at doses ranging from 1×10¹⁶ to 1×10¹⁷ions/cm² and an energy of 50keV. The depth profiles measured by AES showed that post-implantation concentrations of Al and O were higher near the surface. The implanted Alumel and Constantan showed no oxidation supperssing effect, but the implantation at 1×10¹⁷ions/cm² caused significant slowing in the oxidation of Inconel 600 and Chromel, both alloys that contain Cr, oxidation behavior that was similar to that of Ni-Cr-Al alloys.