【摘要】 采用热压烧结方法制备出致密的SiC短纤维和Si3N4颗粒复合增强的BAS玻璃陶瓷基复合材料。利用XRD、SEM、TEM和3点弯曲等分析测试手段研究了物相组成、显微结构、界面结构及室温力学性能。结果表明,BAS能有效地促进复合材料的致密化和实现Si3N4的α→β相转变。复合材料中的BAS为六方相,SiC短纤维具有热压取向性,与BAS基体之间的界面结合紧密。SiC短纤维和Si3N4颗粒对BAS有较为显著的强韧化效果,复合材料的室温弯曲强度和断裂韧性为298MPa和4.38MPa.m1/2,比纯六方BAS玻璃陶瓷分别提高了247%和143%。更多还原

【Abstract】 Compact silicon carbide fiber-reinforced BAS/Si3N4 composite was synthesized by hot-pressing at 1650 ℃under a pressure of 25 MPa for 1 h in 0.1 MPa nitrogen atmosphere. Phase compositions,microstructures,interfacial structures between the fibers and matrix,and the mechanical properties of the composites were studied by means of XRD,SEM TEM and three-point bending methods. The results show that the BAS could benefit densification and partially realize the α→β-Si3N4 phase transformation. Hot-pressing orientation of the high modulous silicon carbide fiber was observed in the hexacelsian matrix. Bond trength between the silicon carbide and the BAS matrix was strong. Appearent reinforcement effects by the silicon carbide fiber and the silicon nitride particles were obtained. The flexural strength and the fracture toughness could reach 298 MPa and 4.38 MPa.m1/2,respectively,which was increased by 247% and 143% in comparison with that of the BAS glass ceramic.更多还原