Ductile particle ceramic matrix composites—Scientific curiosities or engineering materials?

This review is concerned with ductile particle ceramic matrix composites, which are a group of materials comprising micro- or nano-scale metallic particles in a ceramic matrix. The most studied materials have an alumina matrix; nickel, iron, molybdenum, copper, and silver are some of the more frequently used metals. In contrast to conventional cermets and composites containing an interconnected metallic phase, the particles are discrete. The larger particles provide a toughening increment by deforming plastically and bridging an advancing crack. For the nanoscale composites significant improvements in strength have been reported. Improvements in strength and toughness, coupled with changes to elastic properties and thermal conductivity, have led to improved thermal shock resistance and a consideration of these materials for wear applications.