Compressive Surface Stresses Developed in Ceramics by an Oxidation‐Induced Phase Change
- 1 January 1980
- journal article
- Published by Wiley in Journal of the American Ceramic Society
- Vol. 63 (1-2) , 38-40
- https://doi.org/10.1111/j.1151-2916.1980.tb10645.x
Abstract
Silicon nitride/zirconium oxide hot‐pressed materials contain ZrO2‐2xN4x/3 (0.25≤x≤0.43), which readily oxidizes at ≥ 500°C to monoclinic ZrO2. The molar volume increase (∼4 to 5%) of this reaction was used to develop compressive surface stresses. The development of these useful surface stresses was demonstrated with an indentation technique used to measure the apparent critical stress intensity factor (Ka) on the surfaces of materials fabricated with 5 to 30 vol% ZrO2 and subsequently oxidized at 600° to 800°C. The increase in Ka was directly related to the oxidation kinetics and the initial volume content of the unstable phase.Keywords
This publication has 3 references indexed in Scilit:
- Fracture Toughness of Si3N4 as a Function of the Initial α‐Phase ContentJournal of the American Ceramic Society, 1979
- Fracture Toughness Determinations by IndentationJournal of the American Ceramic Society, 1976
- Hot‐Pressed Si3N4 with Zr‐Based AdditionsJournal of the American Ceramic Society, 1975