THE CHARACTERIZATION OF METAL OXIDE FILMS.
Abstract
A theoretical and experimental study of the characterization of thin oxide films formed on iron and two-phase iron-carbon alloys was conducted. Three complimentary experimental approaches were utilized: thin film formation on two-phase iron-carbon bulk materials as related to morphology; the synthesis of iron-carbon alloy powders; and the initial oxidation of iron and iron-carbon alloy powders. Mechanisms have been proposed for the low temperature oxide growth over the typical narrow lamellar structure of pearlitic alloys. It was found that high-surface-area, low-carbon, iron-carbon alloy powders can be synthesized with varying carbon-to-iron ratios, and free from impurities, utilizing a fluidized-bed gas carburization process. Similar efforts to synthesize the iron carbides Fe2C and Fe3C are also described. Characteristic three-stage kinetic oxidation processes for reduced and unreduced iron powders are also described, indicating reaction of adsorbed hydrogen with oxygen, one monolayer oxygen chemisorption on high energy sites, further oxygen chemisorption on low energy sites, and growth of oxide nuclei. The latter two processes appeared to correspond with Uhlig's recent two-stage oxidation theory related to constant density and diffuse space changes. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1968
- Accession Number
- AD0830429
Entities
People
- H. J. Kim
- J. R. Polek
- R. B. Runk
- R. C. Trivedi
- R. W. Coughlin
Organizations
- Lehigh University