Wear of non-segmented and segmented diamond wheels in high-speed deep grinding of carbon fibre-reinforced ceramics

Abstract

Carbon fibre-reinforced ceramics (CFRCs) are relatively new and promising materials for various high-tech. industrial applications due to their superior properties. However, the employment of these materials has been impeded by their high machining costs. A specially designed metal-bonded segmented diamond wheel has been developed in order to reduce the cutting forces and temperatures and enhance the MRR. Studying the wear behaviour and wear mechanisms of the segmented wheel, compared to a non-segmented wheel with the same specification, was necessary for economic assessment of the process. The investigation was conducted for a surface grinding process. The selected cutting conditions assure an acceptable range of the surface roughness and a high material removal rate. The radial wear, the G-ratio and the wear behaviour of the wheels were examined at the specified specific material removals up to 4,704 mm3/mm. Compared to the non-segmented wheel, the segmented wheel has experienced higher radial wear. However, the G-ratio can be increased considerably by the intermittent grinding process. The main wear mechanisms of the segmented wheel are the inter-crystalline grain fracture and grain pull-out, while in the case of non-segmented wheel, the grain flattening is the main wear mechanism. Furthermore, grinding forces and temperatures, which influence the wear behaviour of a wheel considerably, are significantly reduced by the intermittent grinding process. The residual stress analysis showed that the utilized grinding processes have induced just a negligible residual stress into the CFRC workpieces.