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 Al2O3 p latelets in slip-cast ceramic composites relative to the casting surfa ce. The first used the ferrets applied to the platelets by an image an alyzer, and the second involved a manually applied direction for the p latelet axes. Most platelets were oriented more closely to the plane o f the casting surface than to the casting direction. The manual method suggested much greater orientation of the platelets parallel to the c asting surface. Further analysis of the image analysis results, in ter ms oi aspect ratio, suggested that this was due to the fact that the m anual method could not assign an orientation direction for platelet se ctions with small aspect ratios. This was further compounded by an asp ect ratio dependence of platelet orientation. (C) Elsevier Science Inc ., 1997.