Si含量对油茶果壳基SiC陶瓷的结构及性能影响

Effect of Si content on microstructure and properties of camellia oleifera shell-based SiC ceramics

以油茶果壳、硅粉和酚醛树脂为原料,经热压成型、高温原位反应烧结工艺制备油茶果壳基SiC陶瓷。采用热重-示差扫描量热(thermogravimetric-differential scanning calorimetry, TG-DSC)分析研究油茶果壳粉和酚醛树脂的裂解行为;通过X射线衍射仪、扫描电子显微镜、三点弯曲法和阿基米德排水法表征SiC陶瓷物相组成和微观组织,分析SiC陶瓷的抗压强度和孔隙率,基于表征分析结果探讨Si含量对油茶果壳基SiC陶瓷物相组成、微观结构、抗压强度和孔隙率的影响。结果表明:油茶果壳基SiC陶瓷由主晶相β-SiC和游离的Si组成,孔隙结构发达,孔洞呈蜂窝状,大小均匀,孔隙率高(>50%),抗压强度良好(12~18 MPa),随Si含量的增加,孔隙率与抗压强度先增大后减小。

Camellia oleifera shell, silica powder and phenolic resin were adopted as raw materials to prepare camellia oleifera shell-based SiC ceramics by hot-press forming and high temperature in-situ reaction sintering process. Thermogravimetric-differential scanning calorimetry(TG-DSC) analysis was applied to study the cracking behavior of camellia oil shell powder and phenolic resin. X-ray diffractometer, scanning electron microscope three-point bending method and Archimedes drainage method were used to characterize phase composition and microstructure of the SiC ceramics, and analyse compressive strength and porosity of the SiC ceramics, based on the above results to study the effect of Si content on phase composition, microstructure, compressive strength and porosity of SiC ceramics. Experimental results show that the camellia oleifera shell-based SiC ceramics are composed of the main crystalline phase β-SiC and free Si and have a well pore structure where the pore is honeycomb and uniform in size. The camellia oleifera shell-based SiC ceramics have high porosity(>50%) and good compressive strength(12~18 MPa). With the increasing of Si content, the porosity and the compressive strength of the camellia oleifera shell-based SiC ceramics increase first and then decrease. These results indicates that the camellia oleifera shell-based SiC ceramics has a promising development in the fields of hot gas filtration.