Particle-Reinforced Ceramic Matrix Composites-Selected Examples

This paper presents some examples of ceramic matrix composites (CMCs) reinforced with metal or intermetallic phases fabricated by powder consolidation without a liquid phase (melted metal). Composites with a complex structure, which are an advanced group of CMCs called hybrid composites, were described in contrast to conventional composites with a ceramic matrix. In advanced CMCs, their complex structures make it possible to achieve the synergistic effect of the micro- and nanoparticles of the metallic, intermetallic, and ceramic phases on the composite properties, which is not possible in conventional materials. Various combinations of substrates in the form of powder as more than one metal and ceramics with different powder sizes that are used to form hybrid composites were analyzed. The types of CMC microstructures, together with their geometrical schemas and some examples of real ceramic matrix composites, were described. The schemas of composite microstructures showed the possible location of the ceramic, metallic, or intermetallic phases in composites. A new concept of an advanced ceramic-intermetallic composite fabricated by the consolidation of pre-composite powder mixed with ceramic powder was also presented. This concept is based on the selection of substrates, two metals in the form of powder, which will form a new compound, intermetallic material, during processing. Metal powders were milled with ceramic powders to obtain a pre-composite powder consisting of intermetallic material and ceramics. In the next step, the consolidation of pre-composite powder with ceramic powder allows the creation of composites with complex microstructures. Selected examples of real particle-reinforced conventional and hybrid microstructures based on our own investigations were presented. In addition to microstructures, the properties and possible applications of CMCs were analyzed.