METHODS FOR QUANTIFYING MICROSTRUCTURE OF CERAMIC-MATRIX COMPOSITES

Computer based methods have been applied to the quantification and cha racterisation of an alumina-zirconium diboride (Al2O3-ZrB2) ceramic ma trix composite (CMC) containing 5 vol.-%ZrB2 particles. Scanning elect ron microscope images of the microstructure revealed three types of vo lumetric microstructural elements: alumina matrix grains (MG), particl es of ZrB2 (SP), and poles (P). The size and shape of MG, and the size , shape, and distribution of the SP ann P were studied using methods o f modern stereology and mathematical morphology. The spatial distribut ion of the features was also described using unbiased estimates of a c ovariance function (C(r)). It is shown that available methods for quan titative characterisation can be effectively used to obtain a useful d escription of a CMC microstructure. In particular; it is shown that th e system of pores in the composite showed clustering at short distance s while the particles of ZrB2 were distributed more uniformly. Also, t here was no indication of a tendency for poles to cluster around the d iboride particles. (C) 1996 The Institute of Materials.