微波烧结LiCo_(1/3)Ni_(1/3)Mn_(1/3)O_2电磁场与温度场的仿真模拟  

Modeling calculation on the electromagnetic field and temperature field of microwave sintering for LiCo_(1/3)Ni_(1/3)Mn_(1/3)O_2

作　　者：薛源 张正富[1] 沈韬[1] 徐顺涛 吴天涯 

机构地区：[1]昆明理工大学材料科学与工程学院,昆明650093

出　　处：《材料科学与工艺》2017年第6期40-44,共5页Materials Science and Technology

基　　金：国家自然科学基金重点项目(U1202272)

摘　　要：分析了微波烧结的原理和特点,利用COMSOL Multi-physics模拟软件对矩形微波炉进行了仿真模拟,研究了微波烧结正极材料LiCo_(1/3)Ni_(1/3)Mn_(1/3)O_2时电磁场与温度场的分布,测量了粉末样品LiCo_(1/3)Ni_(1/3)Mn_(1/3)O_2的介电常数,并与模拟结果相对照.研究表明:微波在烧结LiCo_(1/3)Ni_(1/3)Mn_(1/3)O_2样品时,炉腔内电磁场的分布受到影响,微波炉内表面的电场强度减弱;材料内部温度场的分布不均匀,材料的下半部分温度较高;同时,在仿真模拟计算过程中,求得LiCo_(1/3)Ni_(1/3)Mn_(1/3)O_2在微波中烧结到不同温度时的能量损耗,根据李赫德涅凯法则计算出其对应的相对介电常数,发现在20~620℃,相对介电常数随温度的上升而变大.根据实验测得的复合介电常数,求出对应温度点LiCo_(1/3)Ni_(1/3)Mn_(1/3)O_2的相对介电常数.利用Origin对仿真模拟计算和实验求得的两组相对介电常数数据进行拟合对比,发现实验求得的LiCo_(1/3)Ni_(1/3)Mn_(1/3)O_2的相对介电常数与仿真模拟计算所得数据趋势吻合.Based on the theory and characteristics of microwave sintering,the microwave sintering process was simulated in the platform of finite element software COMSOL Multi-physics. The distribution of the electromagnetic field and the temperature field was investigated when cathode materials（ LiCo（1/3）Ni（1/3）Mn（1/3）O2）were sintering. The relative permittivity of LiCo（1/3）Ni（1/3）Mn（1/3）O2 was calculated by simulation,which was compared with the experimental result. The results indicate that in the sintering process,the electric field intensity of the inner surface of the microwave oven was weakened and the temperature field distribution of LiCo（1/3）Ni（1/3）Mn（1/3）O2 was uneven. In the simulation process,the energy loss of LiCo（1/3）Ni（1/3）Mn（1/3）O2 sintered at different temperatures in microwave was calculated. According to the Lichnetecker method, the relative permittivity was calculated,which increased with the increase of temperature at 20 ~ 620 ℃. According to the measured dielectric constant,the relative dielectric constant of LiCo（1/3）Ni（1/3）Mn（1/3）O2 was obtained at different temperature. Then,the two sets of data were compared by curve fitting,the relative permittivity obtained by experiments was found to be consistent with the data obtained by simulation.

关 键 词：微波烧结 LiCo1/3Ni1/3Mn1/3O2 矩形微波炉 有限元模拟 相对介电常数 

分 类 号：TM912[电气工程—电力电子与电力传动]