文档介绍：
氮化硅添加对定向梯度多孔碳化硅陶瓷制
备的影响#
刘波波,杨建锋
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(金属材料强度国家重点实验室,西安交通大学,西安,710049)
摘要:利用高温重结晶工艺以氮化硅做造孔剂成功制得定向梯度多孔碳化硅陶瓷,研究 Si3N4添加量对定向
多孔碳化硅陶瓷组织结构和性能的影响。结果表明通过添加 Si3N4获得的多孔碳化硅陶瓷具有气孔率高、从
底部到顶部的孔径尺寸和孔密度连续梯度分布、气孔定向排列的特点。随着 Si3N4含量增加,烧失率逐渐增
大、多孔碳化硅陶瓷中颗粒趋于圆润、孔隙也逐渐减小、颗粒之间的连接更加紧密。X 衍射分析表明,形
成的碳化硅晶体为α-SiC(6H)晶体。随氮化硅含量从 0%增加到 15%,多孔碳化硅陶瓷的总气孔率从 %
增加到 .%,而强度则从 降低到 。
关键词:碳化硅;多孔陶瓷;高温再结晶
中图分类号:
Effect of Nitride addition on directional gradient porous
silicon carbide ceramics
LIU Bobo, YANG Jianfeng
(State Key Laboratory for Mechanical Behavior of Materials, Xi’an Jiaotong University,Xi’an,
710049)
Abstract: The directional SiC porous ceramics by the high-temperature recrystallization process
using silicon nitride as pore formation agent. And the effect of Si3N4 on directional microstructure
and performance of porous silicon carbide ceramic was examined by XRD, SEM analysis. The
results showed that the obtained silicon carbide ceramic had high porosity, continuous gradient
distribution of pore size and pore density from the bottom to the top, indicated the characteristics
of aligned holes by the adding Si3N4. With the Si3N4 content increased, the rate of weight loss
increased, and the silicon carbide particles tend to e rounded, pore size also decreases, the
connection between the particles became more strong. X-ray diffrac