Ceramography of high performance ceramics - Materials, preparation, etching and microstructures - Part X: The microstructure of mixed ceramics

As a rule, the classic high performance ceramics are single phase. To impro ve certain specific properties of the material for use in particular applic ations, special multi-component mixed ceramics were developed. These materi als contain a second, or even third, phase dispersed within them. The compr essive stress caused by this, together with the particular physical and che mical properties of the second or third phase, may improve for example the cutting behaviour, high temperature strength, electrical or thermal conduct ivity and resistance to wear, -thermal shock or -corrosion of the material. As a result, the mechanical preparation and ceramographic etching of such m ixed ceramics is made more difficult because of the combination of Various materials involved. In this article, the preparation and microstructures of a number of technically relevant mixed ceramics of the types oxide-oxide, oxide-non-oxide, and non-oxide-non-oxide are described.