Properties of magnesium based composite materials exhibiting ferromagnetism fabricated by spark plasma sintering

Abstract

In order to possess magnetic properties in the Mg-based composite materials, pure magnesium and Ni–Cu–Zn ferrite (FR) powders were mechanically alloyed (MAed) using a vibrational ball mill, and the produced composite powders were consolidated into the bulk materials by spark plasma sintering (SPS) . Solid-state reaction, hardness, microstructure and magnetic properties of the bulk materials were characterised by X-ray diffraction, Vickers hardness, optical microscopy and vibrating sample magnetometer, respectively. Solid-state reactions between Mg and FR in the bulk materials occurred to form α-Fe and MgO at a sintering temperature of 673 K. In contrast, the formation of Fe3C occurred at 773 K and 873 K. The Vickers hardness of the bulk materials fabricated from MAed 8 h powder at 773 K showed the highest value of 198 HV. This is due to an increase of composite phases formed the intermetallic compounds, such as MgO, α-Fe and Fe3C as increasing MA time. The magnetic property (magnetization) of the bulk materials fabricated at 673 K exhibited the highest value of 1.0×10−5 Wbm/kg due to the formation of α-Fe. The magnetic property (magnetization) of the bulk materials decreased due to the formation of Fe3C as increasing sintering temperature. Ferromagnetism of the Mg-based composite materials was enhanced by the formation of the α-Fe and Fe3C.