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Mechanical and thermal properties of AlN-BN-SiC (ABS) ceramics were used to calculate the R, R 0 , and R 0000 thermal shock parameters. The R parameter values ranged from B4001 to 4501C. Specimens were thermal shocked by water quenching and the critical quench temperatures (DT C ) were compared with those of a baseline SiC composition. The behavior of the ABS was predicted by R parameter calculations while the behavior of the baseline material was predicted by the R 0 calculations due to its higher thermal conductivity (87 W . (m . K) -1 ) as compared with the ABS materials (B30 W . (m . K) À1 ). The highest critical quench temperature for ABS was B4151C with the lowest at 3601C, while the critical quench temperature for the baseline material was 4501C. Using temperature dependent data over an appropriate temperature range (room temperature to the predicted DT C ), the R parameters of the ABS materials were within 151C of predictions. The baseline material was B1.7 times higher than predicted and this was attributed to the highthermal conductivity of the material resulting in soft thermal shock during quench testing.

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