Characterization of oxidation film on SiC ceramic substrate based on indentation method

An indentation method is proposed to characterize the properties of oxidation film on a SiC ceramic substrate. In this method, a series of indentation tests on the oxidation film with different maximum indentation depths were performed. The relationship between the inverse of contact depth and the inverse of reduced modulus was fitted by an exponential function. The moduli of the oxidation film and substrate as well as the thickness of the oxidation film were estimated by analyzing the fitting parameters. In order to validate the method, indentation tests were conducted on SiC substrate to determine the reference modulus of the substrate. Microstructure observation was conducted to measure the reference thickness of the oxidation film. The estimated values agreed well with the reference values. Finite element analysis was also employed to simulate the indentation tests on the oxidation film. The simulation results agreed well with the experimental results.