N_2窑动态气氛及Al_2O_3粉引起的ZnO挥发对MnZn铁氧体机械强度的影响

The Influence of Dynamic Atmosphere in N 2 Kiln and the Zn Evaporization Caused by Al 2O 3 Powders on the Mechanical Strength of MnZn Ferrite Cores

对比研究了Ｎ２窑动态气氛和真空炉静态气氛及Ａｌ２Ｏ３粉对ＭｎＺｎ铁氧体Ｚｎ挥发的影响，并研究了由此导致产品机械强度的变化。Ａｌ２Ｏ３在ＭｎＺｎ铁氧体烧结过程中吸收挥发出Ｚｎ蒸汽，并反应生成ＺｎＡｌ２Ｏ４。与真空炉静态气氛相比，Ｎ２窑动态气氛加剧了ＭｎＺｎ铁氧体的Ｚｎ挥发。由于成分变化，导致晶格常数的改变，从而在铁氧体表面产生很大的内应力，同时表层Ｚｎ挥发导致的松散“框架”结构进一步加剧了这种应力，使产品机械强度大大下降。

The effect of dynamic atmosphere in N 2 push kiln and the static atmosphere in box kiln and the Al 2O 3 powders on the Zn evaporization of ferrite cores were studied.The Al 2O 3 powders will absorb Zinc evaporation in sintering process and produce ZnAl 2O 4.Compared to static atmosphere in box kiln,the dynamic atmosphere in N 2 push kiln will remarkably cause the Zn evaporization.The difference of composition between the surface and the bulk of ferrite core will produce internal stress in ferrite which will greatly reduce the mechanical strength of ferrite cores.