铝硅酸盐纤维增强SiO_2复合材料的制备与性能研究  

Fabrication and Properties of Aluminosilicate Fiber-Reinforced SiO_2 Composites

作　　者：陈健 王义 黄河[1] 孟海东 王小亮 Chen Jian;Wang Yi;Huang He;Meng Haidong;Wang Xiaoliang(Equipment Academy of The Rocket Force, Beijing 100094, China;Science and Technology on Advanced Ceramic Fibers and Composites Laboratory, National University of Defense Technology, Changsha 410073, China)

机构地区：[1]火箭军装备研究院,北京100094 [2]国防科技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》2018年第4期1281-1286,共6页Rare Metal Materials and Engineering

基　　金：国家自然科学基金(51202291)

摘　　要：对SiO_2凝胶的无机化与烧结特性进行了研究,结果表明:SiO_2凝胶为无定形结构;经500℃煅烧后,凝胶中Si-OH完全无机化,随着煅烧温度的继续升高,产物的结晶性逐渐增强,经1400℃煅烧后析出方石英;随着烧结温度的升高,SiO_2陶瓷的相对密度、弹性模量和硬度均逐渐升高。采用溶胶-凝胶工艺制备了三维铝硅酸盐纤维增强SiO_2复合材料,并对热处理温度进行了优化。研究表明:热处理温度为900℃时制备的复合材料的力学性能最优,其密度为1.97 g/cm^3,弯曲强度、剪切强度和断裂韧性分别为119.7±7.5 MPa、10.8±0.7 MPa和4.0±0.4 MPa·m^(1/2)。随着热处理温度的升高,复合材料断面拔出纤维长度逐渐缩短直至消失。The mineralization and sintering behaviors of SiO2 gels were investigated. Results show that after calcining at 500 ℃, the decomposition of Si-OH in the amorphous gels finishes. With the sintering temperature increasing, crystallinity of the products strengthens gradually. After calcining at 1400 ℃, cristobalite is precipitaed from amorphous SiO2. As sintering temperature increases, the relative density, elastic modulus and hardness of SiO2 ceramics all increase gradually. Three-dimensional aluminosilicate fiber-reinforced silica matrix composites were fabricated by sol-gel process and the effects of sintering temperature on the density, microstructure and mechanical properties of the composites were investigated. The results indicate that the composites prepared at 900 ℃ display the highest mechanical properties, whose density is 1.97 g/cm3. The average flexural strength, interlaminar shear strength and fracture toughness of the composites are 119.7±7.5 Mpa, 10.8±0.7 MPa and 4.0±0.4 MPa·m1/2, respectively. Moreover, with the sintering temperature increasing, the pullout fiber shortens gradually and eventually disappears at the composite fracture surface.

关 键 词：氧化物 复合材料 溶胶-凝胶工艺 微观结构 力学性能 

分 类 号：TB332[一般工业技术—材料科学与工程]