氟化钙对常压烧结Si3N4/BN复相陶瓷结构与性能的影响

以微米级Si3N4和h-BN粉末为原料,CaF2–Al2O3–Y2O3为烧结助剂,采用常压烧结工艺制备了BN体积含量为25%的Si3N4/BN复相陶瓷。研究了CaF2添加量对Si3N4/BN复相陶瓷材料力学性能的影响,并通过X射线衍射和场发射扫描电镜分析了复相陶瓷的物相组成和显微组织。结果表明：随着CaF2添加量增加,制备的Si3N4/BN复相陶瓷材料气孔率逐渐增大,收缩率变小,相对密度减小。添加量为2%（质量分数）时,Si3N4/BN复相陶瓷的室温抗弯强度达145.5MPa。添加适量的CaF2可在Si3N4/BN复相陶瓷材料常压烧结过程中较大程度地破坏h-BN的卡片房式结构,将微米级的h-B...

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Bibliographic Details
Published in硅酸盐学报 Vol. 40; no. 8; pp. 1163 - 1168
Main Author 李永锋 刘萍 刘桂武 史忠旗 乔冠军
Format Journal Article
LanguageChinese
Published 2012
Subjects
六方氮化硼
常压烧结
氟化钙–氧化铝–氧化钇
氮化硅
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Summary:以微米级Si3N4和h-BN粉末为原料,CaF2–Al2O3–Y2O3为烧结助剂,采用常压烧结工艺制备了BN体积含量为25%的Si3N4/BN复相陶瓷。研究了CaF2添加量对Si3N4/BN复相陶瓷材料力学性能的影响,并通过X射线衍射和场发射扫描电镜分析了复相陶瓷的物相组成和显微组织。结果表明：随着CaF2添加量增加,制备的Si3N4/BN复相陶瓷材料气孔率逐渐增大,收缩率变小,相对密度减小。添加量为2%（质量分数）时,Si3N4/BN复相陶瓷的室温抗弯强度达145.5MPa。添加适量的CaF2可在Si3N4/BN复相陶瓷材料常压烧结过程中较大程度地破坏h-BN的卡片房式结构,将微米级的h-BN颗粒变成纳米级颗粒。
Bibliography:LI Yongfeng, LIU Ping, LIU Guiwu, SHI Zhongqi, QIAO Guanjun （1. School of Electronic Engineering, Xi＇an University of Posts and Telecommunications, Xi＇an 710121, China; 2. State Key Laboratory for Mechanical Behavior of Materials, Xi＇an Jiaotong University, Xi＇an 710049, China）
Si3N4/BN composites with h-BN of 25% in volume were fabricated via pressureless sintering with micron-sized a-Si3N4 and h-BN powders as starting materials and CaF2, A1203 and Y203 as sintering additives. The effect of CaF2 content on the mechanical properties of Si3Na/BN composites was investigated, and the phase composition and microstructure of the Si3Na/BN composites were analyzed by X-ray diffraction and scanning electron microscopy. The results show that as CaF2 content increases, the porosity of Si3Na/BN composites increases, and its shrinkage and relative density decrease. When the amount of CaF2 is 2% in mass, the Si3N4/BN composite has the highest flexural strength of 145.5 MPa at room-temperature. A moderate amount of CaF2 in
ISSN:0454-5648