Effect of Nanocrystalline Nickel Powder and Co, Mo, Ta, and Al Additions on Isothermal Oxidation Behavior of Ni–17Cr Alloy

In this paper, the effect of nanocrystalline nickel powder developed via high-energy ball milling process and the addition of Co, Mo, Ta, and Al on the isothermal oxidation behavior of Ni–17Cr binary alloy developed by spark plasma sintering system was investigated. The oxidation behavior of the sintered alloys was studied in air at 1100 °C for exposure period up to 312 h. The oxidation rate and kinetics show that the addition of Al and nanocrystalline nickel enhances the oxidation resistance of the binary alloy followed by Mo, Co, and Ta in their reducing order. The formation of the chromia scale was common to all the sintered alloys investigated as confirmed by X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray spectroscopy analysis.