Microstructural characteristics and mechanical properties for Al₂O₃/metal nanocomposities

High density Al₂O₃/W nanocomposite has been successfully fabricated by using controlled reduction and hot-pressing of Al₂O₃/WO₃ mixtures. For realizing desirable microstructures, chemical processing was used to prepare the mixtures by using an inorganic salt as a starting material of W03. TEM investigation revealed that the very fine WO₃ particles surrounded Al₂O₃ particles. During the sintering process under the reductive atmosphere, WO₃ was reduced to metal particles. TEM observation indicated that the nanometer-sized W particles were mainly located within the A1₂O₃ matrix grains. The mechanical properties were improved by dispersing small amount of nanometer-sized metal particles and resultant internal stresses.