摘要
采用应力比为 0 .1,频率为 6 0 Hz的正弦波在室温和 130 0℃ ,10 - 4Pa真空中对 3D- C/Si C复合材料进行了拉 -拉疲劳试验。同时用 SEM分析了疲劳断口特征。结果表明 :若取循环基数为 10 6 ,130 0℃疲劳极限为 2 85 MPa,约为抗拉强度的 94 % ;室温疲劳极限为 2 35 MPa,约为抗拉强度的 85 %。 130 0℃疲劳断口的纤维拔出长度比室温短。疲劳损伤主要起源于纤维束编织交叉部位 ,随着疲劳循环次数的增加 。
Tension tension cyclic fatigue tests were conducted at room temperature and at 1300℃ in 10 4 Pa vacuum under the condition with a sinusoidal loading frequency of 60 Hz and stress ratio of 0 1 for a three dimensional woven C fiber SiC matrix composite (3D C/SiC) prepared by chemical vapor infiltration (CVI) The results show that the fatigue limit (based on 106 cycles) at room temperature is about 235MPa, which is 85% of its ultimate tensile strength , and the fatigue limit at 1300℃ is about 285MPa, which is 94% of its ultimate tensile strength Based on the examination of the damage initiation, propagation and fracture morphology, the fatigue damage of this composite was also investigated Fiber (fibers bundles) pullout length at 1300℃ is shorter than at R T The fatigue damage initiated from the crossing sites of fibers bundles, the damage of matrix surrounding fibers bundles propagates with cyclic numbers
出处
《材料工程》
EI
CAS
CSCD
北大核心
2002年第9期22-25,共4页
Journal of Materials Engineering