The present paper is focused on the cerami-metal composites obtained via different technologies which leads to different microstructures. Microstructures of composites difered in terms of size and distribution of metal phase.
Composites analysed in paper were produced by the following methods:(a) infiltration of porous ceramic by metal, (b) infiltration under high pressure and (c) sintering of ceramic powder coated by metal films. The microstructures were investigated using scanning and electron transmission microscopy.
Different methods of composite fabrication result in specific distribution and size of metal phase. Presureless inflitration of porous ceramic by liquid metal is driven by capillary force and make possibility to produce microstructure with percolation of metal phase in ceramic matrix. The size of metal phase in composite depends on the size of pores. The size of pores influecne also the process of infiltration. Since ceramic preforms with small size of pore are not fully infiltrated. This method is useful to produce composite with size of metal phase in the range of micrometers.
Infiltration under high pressure produces microstructure with metal phase in the range from nano to micrometers. Moreover, it allows to achieve the nanometrical size of ceramic grains.
In the case of ceramic powders covered by metal, compression and hot pressing preserves nanometrical size of metal. Moreover, the grain growth of ceramic grains is suppressed.