Evaluation of Hardness, Local Strength and Contact Fatigue of Brittle Ceramic Coatings at High Temperatures by Hertz Indentation
In this work, Hertz indentation method was proposed to investigate the hardness, local strength and cyclic contact fatigue of brittle ceramic coating at high temperatures. The testing fixture for high temperature tests is designed, which is made of SiC. A Si3N4 ball with a diameter of 5 mm is used as the indenter and the CVD SiC/SiC composite is used as testing samples. The applied loads are ranged from 300 N to 700 N and the temperatures are among of room temperature to 1100 oC. The critical load and indent size are used to calculate the Brinell hardness and local strength of CVD SiC coating at room temperature and high temperatures. The contact damage under different loading number and period are analyzed. The mechanisms for the improved local strength and contact fatigue lifetime are discussed.
Wei Pan and Jianghong Gong
D. T. Wan et al., "Evaluation of Hardness, Local Strength and Contact Fatigue of Brittle Ceramic Coatings at High Temperatures by Hertz Indentation", Key Engineering Materials, Vols. 434-435, pp. 558-561, 2010