Strength ceramic, grinding direction

FIGURE 17.2 Grinding direction and the effect on ceramic strength. Refer to Figure 17.1 for crack nomenclature and orientation. 

The grinding conditions used for finish grinding in this research are shown in Table 4.8 and Table 4.9. Table 4.8 is for the grinding conditions for RBSN ceramic and Table 4.9 is for the almnina ceramic. The grind directions were perpendicular to the direction of the tensile stress in the subsequent flexural strength test, which is groimd transverse to the length of the bar. 

The indentation fracture mechanics approach likens abrasive-workpiece interactions for grinding of ceramics to small-scale indentation events. The deformation and fracture patterns observed for normal contact with a Vickers pyramidal indentor under an applied load P are illustrated in Figure 3.1. A zone of plastic deformation is foimd directly imder the indentor. Two principal crack systems emanate from the plastic zone med-ian/radial and lateral cracks. Median/radial cracks are usually associated with strength degradation and lateral cracks with material removal. 

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