高性能永磁铁氧体快速烧结工艺研究

Research on Rapid Sintering Technology of High Performance Permanent Magnetic Ferrite

用陶瓷工艺制备高性能永磁铁氧体,为实现快速烧结,对其烧结用窑炉各温区的温度及烧结气氛进行了精细化设计,用扫描电子显微镜观察产品断面形貌,用高斯计测其表面磁感应强度B,用浮力法测其表观密度d,用压力试验机测其承受负荷极限P,用永磁铁氧体测量仪检测其磁参数。实验表明：与传统永磁铁氧体烧结技术相比,窑炉降温区的最后一个排风口设置在680~650℃温区上,有效预防了余磁等不良产品的出现,将窑尾的热量用于升温区对成型压坯排水,有利于降温区内温度较快地下降,结合设计的热气流流量控制技术,实现了快速烧结（日出窑量可提高66%）并节约了能源（烧结单位产品耗电量降低41.1%）,加强了窑炉内气体的流动性,窑炉内氧气含量高,改善了磁体的显微结构,从而改善了产品的机械强度与磁性能,尤其是改善了产品的Br与HCJ等磁参数。

High-performance permanent magnetic ferrite was prepared by conventional ceramic technology. In order to achieve rapid sintering, we refined the designed temperature and sintering atmosphere of each temperature zone of the furnace. Researchers observed the fracture surface of the new experimental product with a scanning electron microscope and measured the magnetic induction B of its surface with Gauss meter. In the meantime, they also measured its apparent density d with buoyancy, the load limit P with the pressure testing machines, and the magnetic parameters with the permanent ferrite meter. The results show that compared with the traditional sintering technology of the permanent magnetic ferrite, the new technology of high-performance permanent magnetic ferrite can efficiently prevent the undesirable stuffs like the residual magnetism because the exhaust port at the end of a cooling zone of the furnace is provided in the 680 ~ 650 ℃ temperature region. In addition, the heating in the kiln area which is used for the shaped compacts drainage is conducive for cooling zone temperature to drop quickly. Combined with the designed flow control technology of the hot gas, the present research achieve a rapid sintering（the daily kiln can be increased by 66%） and energy savings（sintered power consumption for per unit of product is reduce by 41.1%）. Besides, the gas liquidity in the furnace was strengthened and oxygen content in the furnace was highly increased. Hence, the present research also improved the microstructure of the magnet, enhance the mechanical strength and magnetic properties, in particular to improve the Br and HCJ and other magnetic parameters.