Process optimization and properties of NiFe2O4 ceramics prepared by spark plasma sintering
YAN Liang1，YAN Biao2
（1. School of intelligent manufacturing and control engineering, Shanghai polytechnic university, Shanghai
201209，China； 2. School of materials science and engineering, Tongji University, Shanghai 201804，China）
Abstract：ingle phase NiFe2O4 ceramics were prepared from NiFe2O4 powder with particle size of 50 nm. The
spark plasma sintering process was optimized. The effects of heating rate and holding time on the phase, micro‐
structure, density and magnetic properties of sintered blocks were studied. The results show that the heating rate
increases from 30 ℃/min to 60 ℃/min, and the density increases significantly to 97.7%. When the heating rate
increases by 100 ℃/min, the density increases to 98.3%, and the hysteresis loss decreases with the increase of
heating rate; When the holding time is extended from 4 min to 12 min, the permeability and density of the block
increase, but when the holding time exceeds 12 min, the density and permeability do not increase but decrease.
The results show that the optimum sintering process is heating rate of 100 ℃/min and holding time of 12 min.
The density of NiFe2O4 ceramic sintered body is 98.3%, the permeability is 13 000 H/m.
2022, Vol. 32 
