Effect of MnO2 addition on properties of NiFe2O4-based cermets

The impact of MnO 2 as an additive on the properties of NiFe 2 O 4 -based cermets prepared by the two-steps sintering method has been investigated. The new material was characterized in terms of the crystal structure, microstructure, linear shrinkage, relative density and porosity. Moreover, the bending strength of NiFe 2 O 4 -based cermets was measured. Differential scanning calorimetry (DSC) and X-ray diffraction analysis (XRD) shows that the addition of MnO 2 has no obvious influence on the crystal structure of the cermets. Scanning electron microscope (SEM) studies reveals that the grain sizes of cermets decreases slightly with doped MnO 2 . The results show that the linear shrinkage, relative density and bending strength increase at first and then decrease slightly. A high-density (99.56%) and high-strength (84.28 MPa) NiFe 2 O 4 -based cermets has been obtained by adding 0.50 wt% MnO 2 into the matrix.