Oxidation of the powder of nickel-chromium based alloy

The oxidation kinetics of a powdered alloy of the Ni-Cr-Ti-Al-Mo-W-Nb system have been investigated. The range of test pressures is from 10-6 mm Hg to 1 atm, temperature range is from 600 to 1100 deg C. The investigation has shown that alloy powders become oxidized in an air-hydrogen mixture proportionally with the partial oxygen pressure. The oxidation process in the diffusion range depends on temperature, partial oxygen pressure, total system pressure and powder layer thickness. The effective oxidation reaction penetration depth reduces as temperature is increased and increases as environmental oxygen concentration is raised, and also in the course of time due to reaction inhibition by the growing thickness of oxidic film