Quasicrystalline Films for Tribological Applications: Role of Stoichiometry Microstructure Transformation Kinetics and Oxide Structure and Chemistry
Abstract
Significant progress was made towards an understanding of phase development and oxidation in the AlCuFe quasicrystalline system. Microstructure analysis by synchrotron diffraction exhibited the route for phase formation from the as-deposited precursor films. Formation of the R-phase occurred at 450 degree, below the previously published value of 475 degree. Preferential oxidation occurs in the near-surface region and temporarily disrupts formation of the R-phase microstructure, despite encapsulation in argon atmosphere. Fluctuation microscopy and other structural analysis showed the presence of an ordered, polycrystalline oxide on the surface of AlCuFe films annealed at 500 degree to 600 degree. This oxide film appeared to consist of aluminum oxide, and lacked copper and iron. The combination of microstructure analysis, phase development on annealing, and analysis of the oxide phase provided fundamental understanding of AlCuFe quasicrystalline coatings in steam engine applications. A tribological testing system capable of operating in a high temperature, steam environment was modified and tested. Room ambient and 100 degree steam Testing of Sb-impregnated graphit-hard ceramic combinations supported the high temperature steam test results at Enginion.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 30, 2004
- Accession Number
- ADA424452
Entities
People
- David Palaith