Crack propagation behavior of nano-sized SiC dispersed multilayered Al₂O₃/3Y-TZP hybrid composites

Multilayered Al₂O₃/3Y-TZP hybrid composites, in which multilayer and nanocomposite structure coexisted, were fabricated using nanocomposite techniques by which fine SiC particles are dispersed into both Al₂O₃ and/or 3Y-TZP layers. All composites were fabricated by stacking of greensheets that prepared by doctor blade method. Microstructural observation by scanning electron microscopy (SEM) confirmed that all multilayered composites were successfully fabricated without any defect and reaction phase. Residual stress measurement using X-ray diffraction (XRD) analysis revealed that residual stress could be controlled by dispersing nano-sized SiC. Upon analysis of crack propagation behavior of these composites, crack deflection was observed at layer boundaries between Al₂O₃ and 3Y-TZP layers; it is considered that the angles of deflection are strongly affected by the magnitude of residual stress.