稀土氧化物对常压烧结氮化硅陶瓷性能的影响

发布时间：2018-06-22 23:58

本文选题：稀土氧化物 + 氮化硅　；参考：《无机材料学报》2017年12期

【摘要】：高导热氮化硅陶瓷是大功率电力电子器件散热的关键候选材料。研究采用稀土氧化物(Re_2O_3)和氧化钛(Ti O_2)烧结助剂体系,通过低温常压烧结方法来制备氮化硅陶瓷,以有效降低成本,满足实际应用的需求。系统研究了烧结助剂种类及含量对Si_3N_4陶瓷的致密化行为、热导率、显微结构以及力学性能的影响。研究发现随着稀土离子半径的增大,材料的致密度和热导率均呈现下降趋势,添加Sm_2O_3后样品最高密度仅为3.14 g/cm~3。但是当Sm_2O_3-Ti O_2烧结助剂含量为8wt%时,样品断裂韧性可达5.76 MPa?m~(1/2)。当添加Lu_2O_3且烧结助剂含量为12wt%时,材料的密度可达3.28 g/cm~3,但是大量存在的第二相导致热导率仅为42.3 W/(m·K)。研究发现该材料具有良好的断裂韧性。经1600℃退火8 h后,Er_2O_3-Ti O_2烧结助剂样品的热导率达到51.8 W/(m·K),基本满足一些功率电路基板材料的实际应用需求。
[Abstract]:High heat conduction silicon nitride ceramics are the key candidate materials for heat dissipation of high-power electronic devices. The study of the preparation of silicon nitride ceramics by using rare earth oxide (Re_2O_3) and titanium oxide (Ti O_2) sintering aids by low temperature atmospheric sintering is to effectively reduce the cost and meet the needs of practical applications. The types of sintering aids and the types of sintering aids are systematically studied. The effect of content on the densification, thermal conductivity, microstructure and mechanical properties of Si_3N_4 ceramics is found. It is found that the density and thermal conductivity of the materials decrease with the increase of the radius of the rare earth ions. The maximum density of the samples after adding Sm_2O_3 is only 3.14 g/cm~3., but when the content of Sm_2O_3-Ti O_2 sintering aids is 8wt% The fracture toughness can reach 5.76 MPa? M~ (1/2). When Lu_2O_3 is added and the content of sintering aids is 12wt%, the density of the material can reach 3.28 g/cm~3, but the thermal conductivity of the secondary phase is only 42.3 W/ (M. K). The study found that the material has good fracture toughness. The thermal conductivity of the Er_2O_3-Ti O_2 sintering assistant sample after 1600 C annealing 8 h Up to 51.8 W/ (M. K), basically meet the practical application requirements of some power circuit substrate materials.
【作者单位】：中国科学院上海硅酸盐研究所高性能陶瓷和超微结构国家重点实验室;上海大学材料科学与工程学院;
【基金】：国家自然科学基金(51572277) 科技部重点研发计划(2016YFB0700300)~~
【分类号】：TQ174.1

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