Processing and Magnetic Properties of Ni-Fe Alloy Dispersed Alumina Nanocomposites

Abstract

An optimum route to fabricate the Al2O3/Ni-Fe alloy nanocomposites with sound microstructure and magnetic properties was investigated. The composites were fabricated by the hot pressing of powder mixtures of Al2O3 and nano-sized Ni-Fe alloy, in which the alloy was prepared by solution-chemistry routes using Ni- and Fe-nitrate powders and a subsequent hydrogen reduction process. Microstructural observation of reduced powder mixture revealed that the Ni-Fe alloy particles of about 20 nm in size were homogeneously surrounded Al2O3, forming nanocomposite powder. The hot-pressed composite showed improved mechanical properties and magnetic response. The properties are discussed in terms of microstructural characteristics such as the distribution and size of Ni-Fe dispersion.