SiAlON-SiC sandwich structures with tailored surface compression

The feasibility of producing high-hardness ceramic sandwich structures, with compressive residual stresses in the faces, was evaluated in this study. The faces were originally chosen to be SiAlON with an SiC core. To produce structures that did not crack during processing, however, it was necessary to hybridize the faces by adding SiC particles to the SiAlON. This modification resulted in a composite face that reduced the thermal expansion mismatch with the core. The residual stresses in the face were measured with an indentation technique and these values agreed well with those measured by X-ray diffraction and calculated from the theory using experimental values.