β-SiAlON晶须的诱导合成和生长机制研究  

Study on Inducing Synthesis and Growth Mechanism of β-SiAlON Whisker

作　　者：岳昌盛[1,2] 彭犇[1,3] 郭敏[1] 张梅[1] 

机构地区：[1]北京科技大学冶金与生态工程学院,北京100083 [2]首钢环保产业事业部,北京100041 [3]中国冶金科工股份有限公司,北京100028

出　　处：《人工晶体学报》2011年第5期1181-1187,共7页Journal of Synthetic Crystals

基　　金：国家自然科学基金(50874013,51074009);国家科技支撑计划资助项目(2011BAB03B02);教育部新世纪优秀人才支持计划(NCET-07-0071,NCET-08-0723)资助项目

摘　　要：以β-SiAlON粉料为晶种,SiC为基体,加入Si粉、Al粉和Al2O3粉在1900 K氮气气氛下合成β-SiAlON晶须,研究了晶须的显微结构、相组成和晶须增韧SiC复合材料的力学性能,并结合热力学研究了晶须的生长机制。结果表明:(1)以β-SiAlON粉料为诱导晶种时可以合成β-SiAlON晶须材料,其生长机制为VLS机制和VS机制;(2)当以VLS机制生长时,晶须合成z值为1.56,直径约为200～300 nm,呈柱状和纤维状,当以VS机制生长时,晶须合成z值为1.76,直径为0.5～1.5μm,呈柱状和竹节状,发育较为规则;(3)晶须相可有效提高复合材料的力学性能,相同组成的复合材料中,当β-SiAlON晶须相的含量较高时,材料可以在气孔率较高(32.1%)条件下获得了较好的抗折强度(55.2 MPa)。β-SiAlON whiskers were synthesized from β-SiAlON powder（inducing seed）,SiC（basal body）,Si powder,Al powder and Al2O3 powder.The microstructure,compositions of β-SiAlON whiskers and mechanical property of β-SiAlON/SiC composite were detailed discussed,and the growth mechanisms of β-SiAlON whiskers based on thermodynamic analysis were subsequently developed in this paper.The results shows that（1）the addition of β-SiAlON seed is beneficial to formation of β-SiAlON whisker,and the vapor-liquid-solid（VLS） and vapor-solid（VS） mechanisms could be adopted to explain the behavior of whiskers growth;（2）while the β-SiAlON whiskers grows in VLS mechanisms,the diameter of rodlike and fibrous wiskers is the range of 200-300 nm and the z value of β-SiAlON whisker is about 1.56;whereas in VS mechanisms,the diameter of rodlike and bamboo-like whiskers with well-developed crystalline is the range of 0.5-1.5 μm and the z value is about 1.76;（3）β-SiAlON whisker has improved the fracture strength of β-SiAlON/SiC composites,the higher flexural strength（55.2 MPa） can be obtained from the composites with many whiskers and in higher porosity（32.1%）.

关 键 词：β-SiAlON晶须 生长机制 微观结构 力学性能 

分 类 号：TQ175[化学工程—硅酸盐工业]