Effects of V2O5 and ZrO2 on Chipping Ratio of MnZn Ferrite Core
Cracking and chipping of MnZn Ferrites usually occur during the grinding process although proper additives such as V2O5can restrain development of cracks. To study the mechanisms, the effects of adding V2O5or ZrO2to MnZn ferrite were investigated by the rattler test. It was confirmed that adding V2O5could improve the toughness of MnZn ferrite while addition of ZrO2showed opposite result. Based on micro-structure analysis, it was found that adding V2O5increased ratio of intergranular fracture mode to the transgranular but adding ZrO2caused more transgranular cracks. Besides, V2O5addition changed its grain size distribution and resulted in some larger grains. Possible mechanisms of the toughness improvement were proposed according the above findings.