Sol-Gel工艺制备三维碳纤维增强Al_2O_3-SiO_2基复合材料研究  

Fabrication and Mechanical Properties of Three-Dimensional Carbon Fiber Reinforced(Al_2O_3-SiO_2) Matrix Composites

作　　者：梁松林[1] 马青松[1] 刘海韬[1] 戴科伟[1] 

机构地区：[1]国防科学技术大学新型陶瓷纤维及其复合材料重点实验室,湖南长沙410073

出　　处：《稀有金属材料与工程》2016年第S1期585-589,共5页Rare Metal Materials and Engineering

摘　　要：以三维五向碳纤维编织件为增强体,以铝硅比为1:2的高固含量的Al2O3-SiO2溶胶为先驱体,制备出3D-Cf/（Al2O3-SiO2）复合材料。研究了溶胶的莫来石化行为,探讨了热处理温度对复合材料微观结构、力学性能、抗氧化性能的影响。结果表明,双相溶胶在1200℃时发生明显的莫来石化反应,1300℃时莫来石化反应基本完成。经18个周期的浸渍-干燥-热处理制备出抗弯曲强度可达220240MPa,并具有良好韧性的3D-Cf/（Al2O3-SiO2）复合材料。经10001600℃空气中氧化30min后,除了1000℃热处理制备的复合材料,1200和1400℃下制备的复合材料均表现出很好的抗氧化效果。热处理温度通过影响基体的致密化状态而影响复合材料的力学性能和抗氧化性能。Three-dimensional carbon fiber reinforced(Al_2O_3-Si O_2) composites were fabricated via a sol infiltration-drying-heating route. The Al2O3/Si O_2 ratio was 1:2 and solid content was 22.5% in Al_2O_3-Si O_2 sol. The mullitization of sol was characterized, and the effects of heat treatment temperature on microstructures, mechanical properties and oxidation resistance of the composites were investigated. It is indicated that the mullitization begins at 1473 K and almost completes at 1573~1673 K. 3D-Cf/(Al2O3-Si O_2) composites are fabricated by 18 cycles of sol infiltration-drying-heating, showing 220~240 MPa in flexural strength and typical fracture behavior. After being oxidized in air at 1000~1600 °C for 30 min, the composites fabricated at 1000 °C exhibit obvious mass loss and decline in mechanical properties. On the contrary, the composites obtained at 1200 and 1400 °C show desirable oxidation resistance. The mechanical properties and oxidation resistance are influenced by the densification condition of the matrix which is determined by heat treatment temperature.

关 键 词：莫来石 三维编织碳纤维 溶胶-凝胶 力学性能 高温抗氧化 

分 类 号：TB332[一般工业技术—材料科学与工程]