Abstract
The effects of aluminum-ion-implantation on the oxidation behavior of NBD 200 Si3N4 were investigated over an implant concentration range of 0-30 at.%, at 800°-1100°C, in 1 atm dry O2. Oxidation of both unimplanted and implanted samples follows a parabolic rate law. The parabolic rate constant decreases and the activation energy increases with aluminum concentration. Smooth and crack-free oxides are formed under the combination of high implant concentrations and low oxidation temperatures. Outward diffusion of Mg2+ from the bulk of NBD 200 to the oxide layer remains the rate-limiting step for aluminum-implanted samples. The enhancement of the oxidation resistance of NBD 200 by aluminum implantation is attributed to the retardation of the outward diffusion of Mg2+.
Original language | English |
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Pages (from-to) | 865-872 |
Number of pages | 8 |
Journal | Journal of the American Ceramic Society |
Volume | 85 |
Issue number | 4 |
DOIs | |
State | Published - Apr 2002 |