Effects of V_2O_5 and ZrO_2 on Chipping Ratio of MnZn Ferrite Core

摘要

Cracking and chipping of MnZn Ferrites usually occur during the grinding process although proper additives such as V_2O_5 can restrain development of cracks. To study the mechanisms, the effects of adding V_2O_5 or ZrO_2 to MnZn ferrite were investigated by the rattler test. It was confirmed that adding V_2O_5 could improve the toughness of MnZn ferrite while addition of ZrO_2 showed opposite result. Based on micro-structure analysis, it was found that adding V_2O_5 increased ratio of intergranular fracture mode to the transgranular but adding ZrO_2 caused more transgranular cracks. Besides, V_2O_5 addition changed its grain size distribution and resulted in some larger grains. Possible mechanisms of the toughness improvement were proposed according the above findings.