流态化气相沉积温度对FeNi50/SiO2复合粉末形成过程及性能影响

Effect of fluidized chemical vapor deposition temperature on formation process and properties of soft magnetic composite particles

为探明流态化气相沉积过程中核壳结构的形成温度,在正硅酸乙酯热分解的热力学基础上,通过设置不同反应温度,在FeNi50合金粉末表面包覆SiO2绝缘层,采用XRD、FTIR、SEM以及VSM等测试分析仪器对粉末形貌、成分和性能进行了表征。结果表明:正硅酸乙酯的热分解温度为612.70℃,合成具有FeNi50/SiO2核壳结构的软磁复合粉末的最低温度为630℃,软磁复合粉末SiO2绝缘包覆层的厚度为0.520μm;随着沉积温度的升高,SiO2绝缘层厚度也随之增加,FeNi50/SiO2复合粉末的饱和磁感应强度逐渐降低,矫顽力几乎无变化,电阻率呈增加趋势,相对于原料FeNi50合金粉末,具有FeNi50/SiO2核壳结构的软磁复合粉末的电阻率提高了近两个数量级。

To find out the formation temperature of the core-shell structures by fluidized chemical vapor deposition,the thermodynamics of thermal decomposition of tetraethyl orthosilicate was analyzed in this paper.Then,the morphology,composition and properties of the samples were characterized by XRD,FTIR,SEM and VSM after the FeNi50 alloy particles were deposited under different temperature.The results show that the thermal decomposition temperature of ethyl orthosilicate is 612.70℃during fluidized chemical vapor deposition process.The soft magnetic composite particles with FeNi50/SiO2 core-shell structures are obtained above 630℃,the average thickness of SiO2 insulation coating layers is 0.520μm,with the increase of deposition temperature,the thickness of SiO2 insulating layer also increases,the coercive force does not change dramatically,the saturation magnetic inductions of the FeNi50/SiO2 composite powder decreases gradually.Compare to original FeNi50 alloy particles,the resistivity of the soft magnetic composite particles with FeNi50/SiO2 core-shell structures increases two orders of magnitude.