摘要
测定了室温下涂碳前后化学气相沉积法(CVD)制备的国产SiC纤维的抗拉强度,发现威布尔分布可以较好地描述SiC纤维的抗拉强度的统计分布。分析得出以下结论,涂碳后与涂碳前的纤维抗拉强度的Weibull模数,及其平均抗拉强度相比,前者明显高于后者。涂碳后SiC纤维的表面缺陷大大减小。随着标距和应变速率的增加,纤维的平均强度逐渐下降,而Weibull模数基本不变。并对断口进行分析,结果表明SiC纤维呈明显的脆性断裂。
Tensile strength of SiC fibers uncoated and coated carbon by Chemical Vapour Deposition （CVD） method was tested at room temperature. Weibull distribution function is found to describe the distribution of the fibers＇ tensile strength excellently. The results show that the Weibull modulus and the average value of tensile strength about the SiC fibers coated carbon were both higher obviously than that of the SiC uncoated carbon. With the increase of gauge length and stain velocity, the average value of SiC fibers＇ tensile strength decrease and the Weibull modulus keep constant. Moreover, through analyzing the fracture of SiC fibers, it is found that a brittle fracture of the fibers can be seen clearly and the method of carbon coating can decrease the surface＇s defect, so the tensile strength of SiC fibers can be increased effectively.
出处
《材料工程》
EI
CAS
CSCD
北大核心
2009年第2期63-66,73,共5页
Journal of Materials Engineering
基金
国家自然科学基金(50371069)
教育部博士点基金(20030699013)
航空科学基金资助项目(04G53044)
