The surfaces of fiber woven composites (FWCs), especially woven ceramic matrix composites (WCMCs), are obviously anisotropic. Many kinds of damage, which are different from traditional homogeneous materials, could be caused by the fabrication and machining process. The old surface evaluation system appropriate for isotropic materials is no longer suitable to WCMCs, thus causing many difficulties in terms of their wide industrial applications. This chapter presents a grading surface measurement and evaluation system for WCMCs based on their microstructures. The system includes four levels: fiber, fiber bundle, cell body, and the whole surface. On the fiber level, the typical forms of fiber damage, and their effects on the surface morphology of WCMCs are analyzed, which lays a foundation for the measurement and evaluation methods on the next three levels. On each subsequent level, the system proposes a set of surface measurement sampling parameter determination methods and surface quality evaluation methods based on the principle of statistics. As demonstrations, the surface measurement and evaluation on each level were processed on a carbon fiber-reinforced silicon carbide matrix composite (Cf/SiC) to illustrate the methodology of the system.
Part of the book: Composite and Nanocomposite Materials
Due to the special structure of the woven ceramic matrix composites, challenges and difficulties in the grinding process gradually emerge. How to ensure the reasonable and reliable application of materials has become a hot topic in the present research. The force model is beneficial to understand, predict, and even control the machining process. This chapter investigates the grinding force and process optimization of woven ceramic matrix composites, especially grinding force modeling, surface quality, and process optimization of woven ceramic matrix composites during grinding. A new force model considering the fiber orientation of WCMC is developed based on the energy balancing theory. Through the construction of a mathematical model, the study demonstrates the correlation of grinding force with the processing parameters and the composite fiber orientation. The optimum process parameters were obtained by aiming at minimum grinding force and maximum surface quality. The results show that the predictable model has good consistency with the experimental results, and fiber orientation has a major influence on the grinding force. This research can be used to predict the grinding force, thus conducting the machining and controlling their processing quality.
Part of the book: Ceramic Materials - Present and Future [Working title]