The Influence Of Additives And Process Factors On The Performance Of Nickel-copper-zinc Ferrite

In this paper, NiCuZn ferrites have been prepared using the traditional solid-state mixing method. Toroidal samples were obtained after being ball-milled, calcinated, granulated, formed and sintered. The effects of additive, calcining temperature, grain size, forming and sintering etc on the magnetic properties of NiCuZn ferrites were investigated and the forming and sintering technology was innovated and improved based on the above investigation. The impact of the factors discussed above on the magnetic properties of NiCuZn ferrites was assessed by using XRD, SEM and optical microscopy to investigate the microstructure of the ferrites. The results showed that the shrinkage ratio is big when the calcinated extent too low and abnormal grain growth appears when the calcinated extent too excessive; proper quantities of Bi₂O3 or MoO3 can promote the grain growth of the ferrite and increase the permeability effectively; the green density increases with the raise of the forming pressure; the samples should be heat treated at 350⁴00℃ for 2 hours in order to completely eliminate the PVA; to raise the sintering temperature and extend the sintering time properly is favorable to the: grain growth and densification of the ferrites so as to the improvement of magnetic: properties of the NiCuZn ferrites.