微波冶金用堇青石莫来石耐火材料制备及性能

摘要

To develop a kind of refractory material suitable for microwave metallurgy,cordierite-mullite refractory materials with different mixture ratios were synthesized by sintering at normal atmosphere and different temperatures.The effects of sintering temperature and mixture ratio on phase composition,bending strength,thermal shock resistance and dielectric properties were analyzed.The results show that the content of remnant corundum phase after sintering decreases with the increase of temperature from 1400 ℃ to 1450 ℃,the volumetric density,the bending strength and the relative dielectric constants increase,the water-absorbing capacity,the apparatus porosity and the dielectric dissipation decreases.The loss of bending strength after 4 times and 8 times of thermal shocks from 1100 ℃ to room temperature in flowing water is 30% and 50%,respectively.Considering the integrated requirements of bending strength,dielectric property and thermal shock resistance,the optimal sintering temperature of this refractory material is 1450 ℃ and the optimal ratio of cordierite and mullite is 1∶ 1.%为探索适合于微波冶金高温反应过程使用的耐高温、抗热震、低微波吸收率耐火材料,采用常压烧结法在不同温度合成了不同配比的堇青石-莫来石质耐火材料.采用XRD分析、三点弯曲法及Angilent阻抗分析等测试了烧结温度及配比对耐火材料物相组成、抗弯强度、抗热震性能及介电性能的影响规律.结果表明,随烧结温度由1400℃提高至1450℃,烧结样品中残留的刚玉相明显减少,耐火材料的体积密度、抗弯强度显著增大,吸水率和显气孔率数值则显著降低;1100℃保温后急速水冷4次和8次热震循环后,耐火材料的抗弯强度损失率分别为30