Abrasive wear damages observation in engineering ceramics using micro-Raman tomography

Abstract

Micro Raman tomographic imaging (mRTI) is an excellent measurement technique that can nondestructively measure and image the fracture state of the crystal lattice inside materials with a high spatial resolution. mRTI has been successfully used for translucent materials such as wide bandgap semiconductor wafers. The applicability of this measurement method was evaluated by observing the wear damage in polycrystalline industrial ceramics materials. The influence of optical diffusion on the surface and inside of polycrystalline materials is a concern for the internal measurements by the optical beam. The quality degradation of spectral signals due to disturbances in the optical beam was confirmed by mRTI measurements on a commercial alumina plate. The application of surface polishing treatment was attempted to reduce the influence of surface optical diffusion. Three kinds of the surfaces were observed by mRTI, as the initial surface of the alumina plate, polished with #400 and #800 diamond abrasive lapping film, respectively. It was confirmed that the effective measurement depth range can be extended by reducing the surface roughness. However, we confirmed that excessive surface polishing may overwrite the damage on the measurement surface, making it difficult to observe the original damage.

Keywords

• ceramics
• alumina
• wear damage
• raman scattering spectroscopy
• depth-slice measurement
• polishing
• surface roughness