固相烧结法制备Mn-Zn铁氧体的工艺

Study on Preparation of Mn-Zn Ferrite by Solid-phase Method

采用固相烧结法制备Mn-Zn铁氧体样品,分别探讨了成型压力、预烧温度、烧结气氛、烧结温度对样品的致密性、相、结构及微结构的影响.样品的相组成成分、微结构及密度分别采用X射线衍射仪(XRD)、扫描电镜(SEM)、阿基米德法进行表征.结果表明:成型压力较小时,生胚体及烧结体的密度都随压力的增大而增大,空气中烧结并随炉冷却,只能生成部分Mn-Zn铁氧体,且有大量的Fe2O3存在;采用氮气保护或空气中烧结在1 300℃时水中淬火、空气中淬火,均能生成单一尖晶石相的Mn-Zn铁氧体.空气中950℃×3 hN2预烧,然后氮气中1 300℃×5 h烧结,得到的样品晶粒大小较为均匀,结合较为紧密,气孔较少。

The samples of Mn - Zn ferrite were prepared by solid - phase sintering method. The effects of sintering atmosphere, calcining temperature, sintering temperature and molding pressure were studied on phase, structure, microstructure and density of the samples respectively. The chemical phase and structural analysis been carried out by X- ray diffraction method （XRD）. The surface micrographs of samples were observed by scanning electron micro- scope（SEM）. The results indicate the density of sintered and unsintered samples increases with the increasing of molding pressure at low molding pressure, the single phase spinel Mn - Zn ferrites can be created by the following methods （ 1 ） sintered in N2 atmosphere （2） sintered in air and then quenched at 1 300 ℃ in air （3） sintered in air and then quenched at 1 300 ℃ in water. The crystal grains combine very tightly with less pore between them and their size is fairly uniform when the samples were calcined at 950 ℃ for 3 h and then sintered at 1 300 ℃ in N2 atmosphere for 5 h.