摘要
开展了SiC(20vol%)-石墨(15vol%)/ZrB2复合材料室温及高温拉伸性能实验,发现高温时复合材料的拉伸强度和弹性模量有所降低,并且具有明显的非线性特征。引入热损伤来表征弹性模量随温度的衰减规律,利用强度统计分析方法确定单向应力状态下材料的机械损伤演化方程,建立了材料在热力耦合条件下的高温拉伸损伤非线性本构模型。分析表明:随着温度的升高,SiC-石墨/ZrB2复合材料的热损伤和机械损伤不断增加,延性增强,且脆性-延性破坏转变温度范围为1 250~1 350℃。
The tensile property tests of SiC(20vol%)-graphite(15vol%)/ZrB2 composites were carried out at room and high temperatures.The reduction of tensile strength and elastic modulus,and the obvious nonlinear behavior for composites were observed at high temperatures.The attenuation law of elastic modulus with temperature was characterized by introducing thermal damage.The mechanical damage evolution equation under the uniaxial stress was determined through the statistical analysis of strength,and then a high temperature tensile damage nonlinear constitutive model was presented under the thermal-mechanical coupling conditions.The results show that,with the increase of temperature,the thermal and mechanical damage of SiC-graphite/ZrB2 composites increase as well as the ductility,and the transition temperature which range from brittle fracture to ductile fracture is 1 250-1 350 ℃.
出处
《复合材料学报》
EI
CAS
CSCD
北大核心
2015年第1期125-130,共6页
Acta Materiae Compositae Sinica
基金
国家自然科学基金(11325210
0916027
11102051)
关键词
ZRB2
陶瓷
复合材料
超高温
微裂纹
损伤
本构模型
ZrB2
ceramic
composites
ultra-high temperature
microcrack
damage
constitutive model
