燃烧温度对火场中软磁材料性能的影响

Temperature Effect on the Properties of Soft Magnetic Materials in the Fire Scene

软磁铁氧体材料在电气设备中应用广泛,在电气火灾中,经历高温烧结的锰锌铁氧体可以作为一种记录火灾历程的残留物,对火灾的发生、发展和蔓延具有一定指向作用。对热处理之后的锰锌铁氧体磁环进行金相组织、微观形貌观察及VSM磁性能测试,掌握不同火场温度对锰锌铁氧体的金相组织、微观形貌以及磁性能的影响。研究表明:随着加热温度的不断升高,锰锌铁氧体的晶粒不断长大,气孔减少并缩小,晶粒边界更明显;铁氧体磁环断面随着加热温度的升高逐渐光滑,断面晶粒表面气孔减少,晶粒呈六边形,且越来越致密细小;锰锌铁氧体饱和磁化强度在300℃时达到最高,在600℃之后随热处理温度升高而升高。

The application of soft magnetic materials ferrite in real life is commonly used in electrical equipment.In electric fires,Mn-Zn ferrites that have undergone high-temperature sintering can be used as a residue to record the occurrence,development and spread of fires.In this paper,through the observation of metallographic structure and micro-morphology of the manganese-zinc-ferrite magnetic ring after heat treatment,as well as a series of tests of VSM magnetic properties,the influence of different heat treatment temperatures on the metallographic structure,microstructure,magnetic properties of Mn-Zn ferrite was recorded.The results show that with the increase of heat treatment temperature,the grains of Mn-Zn ferrite grow,the number of its pores reduces and its size shrinks,and the grain boundaries are becoming more obvious;with the increase of heat treatment temperature,the cross-section of the ferrite ring is becoming gradually smoother,and the number of surface pores of the cross-section grain are reduced,and the crystal grains are hexagonal and become denser and smaller.The saturation magnetization of Mn-Zn ferrite peaks at 300℃and increases with heat treatment temperature after 600℃.