Abrasive Water Jet Machining Mechanisms in Continuous-Fiber Ceramic Composites

Advanced continuous fiber-reinforced ceramic composite (CFCC) materials have been machined with abrasive water jet (AWJ) drilling and cutting processes. Cutting forces, surface microstructure, and retained tensile behaviors were evaluated using dynamometry, surface profilometry, scanning electron microscopy, and tensile testing, respectively. The AWJ surface characteristics, i.e., roughness and the micromechanisms of material removal of CFCCs, were compared with those of a conventional diamond saw cut surface. Material removal mechanisms for AWJ cutting of CFCC consist of a combination of bending, shearing, micromachining, and erosion. The micromechanisms associated with AWJ hole drilling, or piercing on the other hand, are microfracture of fibers and matrix, delamination, and fragmentation of fiber bundles. The tensile mechanical behavior is negligibly different between the AWJ machined and diamond grit ground CFCC materials.