Processing of Nano-Sized Metal Alloy Dispersed Al2O3 Nanocomposites

Abstract

An optimum route to fabricate the ferrous alloy dispersed Al2O3 nanocomposite such as Al2O3/Fe-Ni and Al2O3/Fe-co with sound microstructure and desired properties was investigated. The composites were fabricated by the sintering of powder mixture of Al2O3 and nano-sized ferrous alloy, in which the alloy was prepared by solution-chemistry routes using metal nitrates powders and a subsequent hydrogen reduction process. Microstructural observation of reduced powder mixture revealed that the Fe-Ni or Fe-Co alloy particles of about 20nm in size homogeneously surrounded Al2O3, forming nanocomposite powder. The sinterd Al2O3/Fe-Ni composite showed the formation of FeAl2O4 phase, while the reaction phases were not observed in Al2O3/Fe-Co composite. Hot-pressed Al2O3/Fe-Ni composite showed improved mechanical properties and magnetic response. The properties are discussed in terms of microstructural characteristics such as the distribution and size of alloy particles.