Powder preparation and microstructure for nano-sized metallic iron dispersed MgO based nanocomposites with ferromagnetic response

Abstract

MgO based nanocomposites including ferromagnetic iron particle dispersions, with a volume content <40 vol%, were fabricated by a reduction/sintering of MgO and iron oxide powder mixtures. The oxide powder mixtures were prepared by solution chemical processes to obtain a suitable microstructure of ceramic/metal nanocomposites. Iron-nitrate as a source of metal dispersion was dissolved into alcohol and mixed with MgO powder. After calcination in air, the iron oxide in the powder mixture was reduced by hydrogen. Dense nanocomposites were obtained by pulse electric current sintering (PECS) process. Phase analysis of the synthesized powders as a function of calcination temperature and reduction process was carried out using a system for thermogravimetry and differential thermal analysis (TG-DTA), concurrently with X-ray diffraction (XRD) analysis. According to this preparation process, an MgO/Fe nanocomposite material with enhanced fracture toughness and ferromagnetic responses was successfully fabricated.