The use of image analysis in the characterization of partially oriented ceramic matrix composites

Two methods were used to determine the in-plane orientation of Al2O2 platelets in slip-cast ceramic composites relative to the casting surface. The first used the ferrets applied to the platelets by an image analyzer, and the second involved a manually applied direction for the platelet axes. Most platelets were oriented more closely to the plane of the casting surface than to the casting direction. The manual method suggested much greater orientation of the platelets parallel to the casting surface. Further analysis of the image analysis results, in terms of aspect ratio, suggested that this was due to the fact that the manual method could not assign an orientation direction for platelet sections with small aspect ratios. This was further compounded by an aspect ratio dependence of platelet orientation.