Synthesis and magnetic properties of a Fe-Ni alloy dispersed Al_2O_3 nanocomposite powder prepared by a chemical method

摘要

There has been strong interest in nanocomposite materials, in which nano-sized particles are dispersed in a ceramic matrix of micrometer grain size, due to the outstanding improvements of mechanical properties, compared with monolithic ceramics [1]. Moreover, ceramic nanocomposites that have functional metals as the dispersion, such as Ni-dispersed Al_2O_3 [2] and Ag-dispersed lead zirconate titanate (PZT) [3], have been found to exhibit attractive functions such as ferro-magnetism and high dielectric constant without losing their excellent mechanical properties. However, dispersion of nano-sized particles of an alloy rather than a pure metal is of great interest because of the larger potential for fabricating ceramic-based materials having a useful combination of mechanical and functional properties. Thus, we have concentrated on the synthesis of alloy phase dispersed Al_2O_3 nanocomposite powder. In the present study, Fe-50 wt% Ni alloy, which shows ferro-magnetism, was selected as the dispersant.