Microstructural characteristics and mechanical properties for Al2O3/metal nanocomposites

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 WO3. 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 Al2O3 matrix grains. The mechanical properties were improved by dispersing small amount of nanometer-sized metal particles and resultant internal stresses.