层压法制备SiC_f/Al_2O_3复合材料的抗弯性能研究

Study on Bending Performance of SiC_f/Al_2O_3 Composite Fabricated by Lamination Method

以氧化铝为填料,硅溶胶为粘结剂,碳化硅纤维布为增强纤维,使用层压法制备SiCf/Al2O3复合材料,并对该复合材料做了抗弯性能试验。结果显示,随处理温度的升高,基体缓慢释放出的结合水会对纤维造成氧化损伤,使试样的抗弯性能下降,但是材料始终表现出非脆性断裂行为,这与基体与纤维之间未形成强结合有关;包裹氧化硼玻璃后在空气中对SiCf/Al2O3进行处理后,氧化硼玻璃能有效阻止空气与纤维的接触,防止了纤维在高温下被氧化,分析表明在600、700、800℃保温0.5、1、1.5、2 h后,抗弯强度变化不大。

SiCf /Al2O3 composite was prepared by lamination method,adopting Al2O3 powder as filler,ludox as binder and SiC fiber carbon cloth as reinforcement phase.The bending performance of the composite were measured.The results show that the bending strength of the composite declines as the vacuum treatment temperature rises,due to the oxidation of SiC fiber in water vapor released from SiO2 sol.The fracture mode keeps un-brittle rupture,which is related to the bending strength between matrix and fiber.But the bending strength of the composite almost keeps unchanged after heat-treated at 600,700,800 ℃ for 0.5,1,1.5,2 h,respectively.