稀土Sm2O3对多孔Si2N2O陶瓷显微结构和性能的影响  

Structure and Performance of Porous Silicon Oxynitride Ceramics with Sm2O3 Additive

作　　者：卫莉婷 樊磊[2] 温江波[2] 王红洁[2] WEI Liting;FAN Lei;WEN Jiangbo;WANG Hongjie(Yuncheng University,Yuncheng 044000,Shanxi,China;State Key Laboratory for Mechanical Behavior of Materials,Xi＇an Jiaotong University,Xi＇an 710049,China)

机构地区：[1]运城学院,山西运城044000 [2]西安交通大学金属材料强度国家重点实验室,西安710049

出　　处：《硅酸盐学报》2018年第6期780-784,共5页Journal of The Chinese Ceramic Society

基　　金：国家自然科学基金重点项目(51272206);运城学院应用研究项目(CY-2017009)资助

摘　　要：以Si3N4与Si O2为初始原料、Sm2O3为烧结助剂,通过无压烧结制备了气孔率不同的多孔Si2N2O陶瓷。研究了烧结温度、助剂含量对烧结后的产物的影响;测试了多孔Si2N2O陶瓷的力学性能、介电性能和抗氧化性能。结果表明：烧结温度过高或助剂含量过高都会导致Si2N2O相的分解;助剂含量对Si2N2O陶瓷微观组织产生明显的影响,随着助剂含量的增多,其显微结构由细小层片状过渡到板状晶粒再到短纤维搭接的板状晶粒结构,所制备的Si2N2O陶瓷比Si3N4陶瓷具有更优异的性能,抗弯强度为220 MPa,介电常数ε为4.1,介电损耗tanδ〈0.005。1 400℃氧化10 h,Si2N2O与Si3N4的质量增量分别为0.6%与2.1%。Porous Si2N2O ceramics with different porosities were fabricated using Si3N4 and SiO2 as starting materials and Sm2O3 as a sintering additive by a gas pressure sintering process under N2 atmosphere. The influences of sintering temperature and Sm2O3 content on the phase for Si2N2O ceramics were investigated. The XRD analysis shows that the increase of either sintering temperature or Sm2O3 content will facilitate the decomposition of Si2N2O into Si3N4. The content of sintering aids has an effect on the microstructure, and the morphology of Si2N2O grains varies from lamellar grains through plate-like grains to short fiber lapped plate-like grains when the sintering addictive content increases. The elongated Si2N2O crystals contribute to the high flexural strength（i.e., 220–356 MPa at room temperature）. The dielectric properties are mainly affected due to the porosity. The as-sintered Si2N2O ceramics show both better mechanical properties and more excellent oxidation resistance with low dielectric constant（ε=4.1） and loss tangent（tanδ〈0.005）, compared to Si3N4. The weight gains of Si2N2O and Si3N4 are 0.6% and 2.1%, respectively, after oxidation at 1400 ℃ for 10 h, indicating that the gas pressure sintered Si2N2O ceramic could be used as a promising high-temperature wave transparent material.

关 键 词：氧氮化硅 介电性能 抗氧化性能 氧化钐 

分 类 号：TQ174[化学工程—陶瓷工业]