Shape, Size and Distribution of Metal Particles Embedded in a Ceramic Matrix

Abstract

The presented paper is a review of own work done on two systems of composites, Al2O3‑Ni and Al2O3-Fe. The previous own results of research into shape, size and distribution of the metal particles and spinel phase embedded in a ceramic matrix are referred to and new ones are presented. Metal particles as well as spinel can be distributed uniformly in a ceramic matrix or can form graded structures. Most often there are agglomerates of metal or spinel particles rather than separated particles embedded in ceramic grains. In composites the growing spinel forms a thick oval layer around a metal particle, however, separate spinel areas embedded in a ceramic matrix are noticed, too. Also, the characteristic “doughnut” shape of spinel is found. Since the metal and spinel phase influence the mechanical properties, the required properties of ceramic-metal composites can be tailored by changing the size, shape and distribution of the phases.