Oxidative corrosion resistance of a CrxFeyNi1-x-y composition spread alloy film (CSAF) in dry air

• Published in: Applied surface science 2024-10, Vol.669, Article 160391
• Main Authors: Ferris, Camille, Golio, Nicholas, Martinez, Hervé, Gellman, Andrew J.
• Format: Article
• Language: English
• Subjects: Chromium; Iron; Nickel; Oxidation resistance; Thin film alloys; X-ray photoelectron spectroscopy
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2024.160391

[Display omitted] •The critical Cr concentration of CrxFeyNi1-x-y alloys is between 18–26 at.%.•A sharp, visually distinct passivation boundary is observed reproducibly.•Depth profiles confirm that the visual boundary demarcates the onset of oxidation.•The trajectory of the critical Cr composition is plotted within composition space.•These results confirm the trend towards higher Cr content stainless steels. Composition Spread Alloy Films (CSAFs) were used to study the resistance to oxidative corrosion of CrxFeyNi1-x-y alloys in dry air and determine the critical Cr composition, xCr∗, necessary to prevent bulk oxidation. CrxFeyNi1-x-y CSAFs were made using physical vapor deposition (PVD) and then oxidized in dry air between 100 – 500 °C for periods of 1 h. A sharp passivation boundary was observed at 300 °C separating alloys showing evidence of heavy oxidation from Cr-rich alloys that were passivated. X-ray photoelectron spectroscopy (XPS) depth profiling was used to measure the extent of oxidation and penetration depth of the oxide layer on either side of the passivation boundary. XPS measurements confirmed the presence of a critical Cr composition, xCr∗, ranging from 18 to 26 at.%. For alloys with xCr≥xCr∗, a sufficiently thick passivating layer of oxidized Cr, Cr(ox), had formed on the top surface preventing the oxidative corrosion of either Fe or Ni. On the other hand, when xCr