摘要
微波烧结技术已被广泛应用于陶瓷材料的制备中,然而微波烧结的氮化硅基陶瓷材料存在性能一致性差、升温过程功率波动大等问题。为此,通过仿真比较了微波烧结腔有无负载、不同试样放置方式下电场和温度场的分布特性,分析了微波功率对电场和温度场分布的影响规律,提出了微波烧结功率选择原则,通过实验研究比较了各温度段升温速率及匹配功率对陶瓷力学性能的影响。结果表明:微波场中添加负载、试样紧密排列有助于提高电场均匀性,在0~800℃、800~1400℃、1400~1650℃温度段分别选择升温速率80℃/min、50℃/min和25℃/min,各温度段匹配的功率分别选择1600 W、1800 W和2200 W,可获得力学性能最佳的氮化硅基陶瓷材料,其维氏硬度达(18.278±0.233)GPa,断裂韧度达(8.588±0.165)MPa·m^(1/2),与匀速升温工艺相比,材料硬度提高14.8%,韧度提高22.5%,且该调控策略能有效提高陶瓷材料力学性能的一致性。
Microwave sintering technology was widely used in preparation of ceramic materials.However,the silicon nitride based ceramic materials sintered by microwave had problems such as poor performance consistency and large power fluctuations during heating processes.Therefore,the distribution characteristics of electric field and temperature field were compared in microwave sintering chambers with or without loads and different sample placement methods according to simulation.The influences of microwave power on the distribution of electric field and temperature field were analyzed,and the principle of microwave sintering power selection was proposed.The influences of heating rate and matching power on mechanics properties of ceramics in different temperature ranges were compared through experimental results.The results show that adding loads and arranging samples tightly in microwave field are beneficial for improving the uniformity of the electric field.The experimental results indicate that the Si 3N 4-based ceramic materials with the best mechanics properties may be obtained by selecting heating rates of 80℃/min,50℃/min and 25℃/min at 0~800℃,800~1400℃and 1400~1650℃respectively,and matching powers of 1600 W,1800 W and 2200 W are selected for each temperature range.The Vickers hardness reaches(18.278±0.233)GPa,and the fracture toughness reaches(8.588±0.165)MPa·m^(1/2).Compared with the uniform heating processes,the hardness increases by 14.8%,the toughness increases by 22.5%,and the consistency of ceramic material properties may be improved effectively with the regulation strategy herein.
作者
徐伟伟
张作轩
朱松青
殷增斌
XU Weiwei;ZHANG Zuoxuan;ZHU Songqing;YIN Zengbin(School of Mechanical Engineering,Nanjing Institute of Technology,Nanjing,211167;School of Mechanical Engineering,Nanjing University of Science and Technology,Nanjing,210094)
出处
《中国机械工程》
北大核心
2025年第3期435-443,共9页
China Mechanical Engineering
基金
国家自然科学基金(52205471,52305470)
南京工程学院人才引进科研启动基金(YKJ202004)。
关键词
氮化硅基陶瓷
微波烧结
调控策略
微波功率
Si 3N 4-based ceramics
microwave sintering
control strategy
microwave power
