Study on inducing synthesis and growth mechanism of β-SiAlON whisker

作者：Yue Chang Sheng; Peng Ben; Guo Min; Zhang Mei^*

来源：Journal of Synthetic Crystals, 2011, 40(5): 1181-1187.

• Al powder
• Growth mechanism
• Growth mechanisms
• Sialon powders
• Thermo dynamic analysis
• Vapor solid mechanism
• Vapor-liquid-solid
• VLS mechanism
• Z value

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%).

• 出版日期2011
• 单位北京科技大学