Interfacial behavior of Fe76Si9B10P5/Zn0.5Ni0.5Fe2O4 amorphous soft magnetic composite during spark plasma sintering process

Fe76Si9B10P5/Zn0.5Ni0.5Fe2O4 amorphous composite with micro-cellular structure and high electrical resistivity was prepared by spark plasma sintering (SPS) at 487 °C. XRD and SEM results showed that the Fe76Si9B10P5 alloy powders remained the amorphous state and the composite was dense. A fusion zone at interface of Fe76Si9B10P5 cell body and Zn0.5Ni0.5Fe2O4 cell wall was observed by TEM, which also indicates the formation of local high temperature. The interface bonding based on the formation of local high temperature in SPS process was observed. It is believed that the tip effect of Zn0.5Ni0.5Fe2O4 nanoparticles promotes the local discharging and plasmas creation in the gaps, and the discharging energy forms an instantaneous local high temperature to complete the local sintering and the densification of Zn0.5Ni0.5Fe2O4 particles at a low nominal sinter temperature. Simultaneously, the local high temperature stimulates the adjacent gaps discharging, thus facilitate the continuous formation of new discharging path. Finally, sintering and densification of the amorphous composite is complete.