Thermal Cycling Damage Mechanisms of C/SiC Composites in Displacement Constraint and Oxidizing Atmosphere
Thermal Cycling Damage Mechanisms of C/SiC Composites in Displacement Constraint and Oxidizing Atmosphere
复制标题
DOI：
10.1111/j.1551-2916.2006.01012.x
复制
发表时间：
2006-07
影响因子：
3.9
通讯作者：
H. Mei;Lai-fei Cheng;Litong Zhang
中科院分区：
文献类型：
--
作者：
H. Mei;Lai-fei Cheng;Litong Zhang
两端固定的三维C/SiC复合材料试样在900° ~ 1200°C温度循环时产生62.5MPa的约束应力。由于涂层和基体开裂、纤维脱粘、滑动和复合材料断裂，循环应力导致50次循环内的最大损伤应变为0.06%。这种受约束的试样伸长还通过基线约束应力的降低导致复合材料上的最终压缩应力为14 MPa。高温循环下的湿氧环境，伴随着应力的作用，会加剧复合材料内部和外部纤维之间的交替氧化损伤。
A constraint stress of 62.5 MPa is created on a three-dimensional C/SiC composite specimen whose both ends are fixed when temperature is cycled between 900° and 1200°C. The cyclic stress results in a maximum damage strain of 0.06% within 50 cycles owing to coating and matrix cracking, fiber debonding, sliding, and breaking in the composite. This constrained specimen elongation also leads to a final compressive stress of 14 MPa on the composite through a decrease in the baseline constraint stress. Wet oxygen atmosphere at a high cyclic temperature, concomitant with stresses, can aggravate the damage situation by alternate oxidation between internal and external fibers in composites.