摘要
利用LPCVI技术制备了三维连续纤维增韧的碳化硅基复合材料 ,研究了复合材料致密度、界面相厚度以及纤维类型对碳化硅基复合材料性能的影响 .研究表明 :(1 )随复合材料致密度的提高 ,由于基体和纤维之间力的传递效果变好 ,复合材料性能提高 .(2 )界面相厚度对复合材料性能的影响 ,可从其对界面结合强度、脱粘面上滑移阻力、界面相制备过程碳纤维的损伤程度以及界面相在基体沉积过程中对纤维的保护作用 4个方面进行解释 ,界面相厚度为 0 .1 9μm时碳纤维对碳化硅的增韧效果较好 .(3)对于由M4 0 ,T30 0 2种纤维增韧的碳化硅基复合材料 ,由于纤维物理性能不同及由此决定的复合材料中残余热应力及应力再分布情况不同 ,使复合材料的性能发生很大变化 .T30 0增韧效果较好 ,其增韧的复合材料的弯曲强度为 4 59MPa ,断裂韧性为 2 0 .0MPa·m1/2 ,断裂功为 2 51 70J·m- 2 .
D continuous fiber_reinforced silicon carbide composites were manufactured by LPCVI. Effects of the densification of the composites, pyrolitic carbon interphase thickness and the type of fiber on the properties of the composites were studied. The following observations were made:(1) The properties of the composites increase as the densification increased because the degree of load transfer is improved as the densification increased. (2) The effect of interphases thickness on the properties of the composites can be interpreted from the effects of the interphases thickness on interfacial bonding strength,slide stress on the debonding face, the degradation of fiber during the manufacture of pyrolitic carbon interphase and the protective role of interphase to fiber. The composites with higher bending strength and fracture toughness can be achieved when the pyrolitic carbon interphase thickness is 0.19 μm. (3) The type of fiber affects the properties of composites apparently. This is due to the effects of the properties of fiber on residual thermal stress and stress redistribution. SiC matrix composites reinforced by T300 have better properties ( σ f=459 MPa, K Ⅰc =20.0 MPa·m 1/2 , W f=25 170 J·m -2 ).
出处
《硅酸盐学报》
EI
CAS
CSCD
北大核心
2000年第5期437-440,共4页
Journal of The Chinese Ceramic Society
关键词
碳化硅基
复合材料
力学性
碳纤维
增韧
silicon carbide matrix composites
fiber
interphase
densification
mechanical properties
