Abstract
The tribological properties of a B2-type Al-Pd-Mn quasicrystal approximant were investigated and compared with those of an Al-Pd-Mn icosahedral quasicrystal. The approximant was of the β phase, having a crystalline CsCl-type structure and nominal composition Al48Pd42Mn10. Friction coefficients measured in ultrahigh vacuum between a pair of Al48Pd42Mn10 samples having truly clean surfaces were found to be twice as high as those reported for the Al70Pd21Mn9 quasicrystal. When the surfaces were oxidized by exposure to O2 or H2O, the friction coefficients decreased by roughly a factor of two for both materials but the friction coefficient for the approximant remained roughly twice that of the quasicrystal. The rate of oxidation of the approximant was found to be one order of magnitude higher than that of the quasicrystal. This corroborates findings that suggest that quasicrystals exhibit an inherent resistance to oxidation and corrosion. Vickers hardness measurements show that the quasicrystal is roughly three times as hard as the approximant.
Original language | English |
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Pages (from-to) | 1447-1456 |
Number of pages | 10 |
Journal | Journal of Materials Research |
Volume | 18 |
Issue number | 6 |
DOIs | |
State | Published - Jun 2003 |
Externally published | Yes |
Funding
This work was supported by the Director, Office of Energy Research, Office of Basic Energy Sciences, Material Sciences Division, of the United States Department of Energy under Contract No. W-405-Eng-82, and instrumentation was developed with support from the Air Force Office of Scientific Research under Grant No. AFOSR F49620-01-1-0069.