Ceramic Matrix Composites Reinforced with Metal Nanoparticles

Abstract

This project describes the formation of Al2O3-Ag or Al2O3-Ti nanocomposites via high-energy planetary milling combined with pressureless sintering. From the main results, it was found that after milling, the powder was constituted by very fine particles ~ 200 nm average size, and it presents a good distribution of metal and ceramic particles. Observations of microstructure of sintered samples by electron microscopy, illustrate dense composite materials with a homogeneous sharing of the metal in the alumina-matrix. The microstructure of the composites with silver is much finer than the microstructure of the composites with titanium. From fracture toughness measurements, estimated by the fracture indentation method, it has been determined that metal additions improved fracture toughness even more than 50 % with respect to the fracture toughness of monolithic-alumina. In conclusion, composites of the Al2O3-Ag or Al2O3-Ti systems are materials that have excellent mechanical properties which may result in their commercial use. Additionally, the proposed route for the manufacture of these composites can be a low-cost method.