Ceramics and Composite Materials

Biography

Biography: Xinli Tian

Abstract

Edge-chipping referred to the fact that the edges of hard, brittle materials are easily broken during processing. This problem has brought many difficulties to their quality control. In fact, it was that the machining process itself destroyed materials, even though it could be controlled. Based on this principle, a new machining technology based on crack propagation driven by edge-chipping effect was proposed here. Multiple flanges caused by the cutting could increase the number of edges. Additionally, the fracture defects were prefabricated on the surface of flanges. When the turning tool made of cemented carbide came into contact with the surface of the ceramics, under the intermittent impact. The fractures were generated on the sides of flanges contacted with the tool and the prefabricated micro cracks were expanded rapidly under this three-dimensional stress field applied externally by the tool. In addition, due to the stress release toward the free surface, the cracks would expand to the surfaces of newly generated edges and the chips would be broken off continuously, resulting in irregular edge-chipping and removal of material pieces. Furthermore, based on the spatial distribution of grayscale images, the surface quality after rough processing under the different conditions was reasonably reflected with the grayscale co-occurrence matrix (GLCM). With the new processing technology, these cracks became advantageous under specific conditions. Therefore, the high external energy and ultra-hard tools required for the traditional processing technologies could be significantly reduced and the ceramics could be removed with less energy consumption and the tools with the hardness of lower than its own one. Therefore, it not only could reduce the processing costs, but also could promote the extensive applications of engineering ceramic materials.