高频无极灯用NiZn系铁氧体材料研究

发布时间：2018-06-29 09:30

  本文选题：高频无极灯 + NiCuZn铁氧体　； 参考：《电子科技大学》2014年硕士论文

【摘要】：人造电光源发展迅速,现已进入以高频无极灯和发光二极管(Light Emitting Diode,LED)为代表的第四代绿色电光源时代。高频无极灯具有发光效率高、使用寿命长、显色指数高、无频闪、环保等优点,因此对节能降耗、用眼健康、绿色环保有重大意义。但目前由于高频无极灯电磁耦合器使用的Ni系铁氧体磁心居里温度(Tc)较低、截止频率(fr)低、高频损耗(Pcv)温度特性差、生产成本高等缺点,致使高频无极灯的推广和普及面临不小的困难。因此本文针对目前高频无极灯用Ni系铁氧体的缺点,开展了以下工作。采用少量Cu2+取代Ni2+,形成了Fe2O3、NiO、ZnO和CuO四元体系主配方,降低了烧结温度,细化了晶粒,并使得Snoek乘积和电阻率提高。同时优化主配方中的ZnO含量,确保样品具有高Tc和高fr。当ZnO含量从17mol%增加到24mol%时,Tc从375℃逐渐下降到275℃;起始磁导率(μi)从99逐渐增大到236,fr从75MHz逐渐降低到26MHz;当ZnO含量为18mol%时,样品的Pcv最低为714mW/cm3(3MHz,10mT,100℃)。在优化后的NiCuZn主配方基础上,分别采用微量Ta2O5和Co2O3掺杂。研究结果表明:Ta2O5具有细化NiCuZn铁氧体晶粒的作用,可降低材料的烧结密度。随着Ta2O5添加量的增加,样品的饱和磁感应强度(Bs)和μi单调减小,矫顽力(Hc)则逐渐增大,fr逐渐升高,而Pcv呈先降低后增加的趋势,其主导因素由剩余损耗(Pr)逐渐过渡到磁滞损耗(Ph)。当Ta2O5添加量为0.12wt%时,样品在3MHz,10mT,100℃下总损耗最小,为139m W/cm3,其中Ph和Pr分别为93mW/cm3和46mW/cm3。Co2O3的添加量在0~1.00wt%的变化范围内,样品的平均晶粒尺寸略有减小,μi逐渐下降,fr逐渐升高。在3MHz,10mT,25~140℃条件下,随着Co2O3添加量的增加,磁心损耗单调减小。采用适量MgO取代价格昂贵的NiO,降低了磁心成本。随着MgO含量的增加,烧结密度逐渐降低,Tc近似呈线性下降,从362℃逐渐下降到291℃;μi有一定程度下降,fr变化不大;Pcv也无显著变化,当MgO含量为8mol%时,Pcv在各个温度点下相对较低。在优化后的NiMgCuZn主配方中采用Ta2O5和Co2O3复合添加,制备的样品晶粒尺寸较小且均匀;随着Ta2O5和Co2O3添加量的增加,μi逐渐降低,fr逐渐升高;当Ta2O5和Co2O3的添加量分别为0.50wt%和0.36wt%时,样品在3MHz,10mT,100℃下的损耗最低,仅为25mW/cm3。通过以上工作制备了NiCuZn和NiMgCuZn两种铁氧体磁心,其性能参数均达到了高频无极灯的适用标准,其中NiMgCuZn铁氧体大大降低了高频无极灯磁心的成本。采用本文制备的两种磁心绕制了电磁耦合器,并成功点亮了高频无极灯。
[Abstract]:With the rapid development of artificial electric light source, it has entered the fourth generation green electric light source era represented by high frequency electrodeless lamp and light emitting diode (LED). High frequency electrodeless lamps have the advantages of high luminous efficiency, long service life, high color index, no stroboscopic, environmental protection and so on. Therefore, it is of great significance to save energy and reduce consumption, eye health and green environmental protection. However, due to the low Curie temperature (Tc) of Ni ferrite core, low cut-off frequency (fr), low temperature characteristic of high frequency loss (PcV), high production cost and so on, the electromagnetic coupler of high frequency electrodeless lamp has many disadvantages, such as low Curie temperature (Tc), low cut-off frequency (fr), high production cost and so on. As a result, the promotion and popularization of high frequency pole-less lamps are faced with great difficulties. Therefore, in view of the shortcomings of Ni ferrite used in high frequency electrodeless lamps, the following work has been carried out in this paper. A small amount of Cu _ 2 was used to replace Ni _ 2 to form the main formula of Fe _ 2O _ 3 / nio _ (ZnO) and CuO quaternary systems. The sintering temperature was reduced, the grain size was refined, and the Snoek product and resistivity were increased. At the same time, the content of ZnO in the main formula is optimized to ensure that the sample has high Tc and high fr. When ZnO content increased from 17 mol% to 24 mol%, Tc decreased gradually from 375 鈩，

本文编号：2081674