三种不同碳纤维的纳米压痕行为
Nano indentation behavior of three different types of carbon fibers

采用Raman光谱对三种不同碳纤维（K223HE、HTA40和T700SC）的微晶尺寸进行了表征，利用纳米压痕技术对三种碳纤维的横向弹性模量和硬度进行了测试，结合Weibull分布函数对碳纤维的横向弹性模量和硬度进行统计分析。结果表明，中间相沥青基碳纤维K223HE的微晶长度最大，为39.43 nm±2.63 nm，PAN基碳纤维HTA40和T700SC的微晶尺寸基本相同，分别为4.63 nm±0.09 nm和4.89 nm±0.06 nm。在纳米压痕载荷-深度曲线上，碳纤维K223HE的残余变形大（75.34 nm±17.07 nm），压入功恢复率低（65.89%）。碳纤维HTA40、K223HE和T700SC的特征横向弹性模量为19.52 GPa、11.99 GPa和 17.92 GPa。三种碳纤维的横向弹性模量的Weibull分布模数分别为25.26、6.85和8.07，说明HTA40碳纤维的性能均匀性最好。碳纤维的纳米压痕行为的差异主要是由碳纤维中微晶的完整性、择优取向性的差异引起的。 The crystallite size of the three different carbon fibers (K223HE, HTA40 and T700SC) was characterized by Raman spectroscopy. The transverse elastic modulus and hardness of the carbon fibers were measured by nano indentation technique, and the data scatter was analyzed by two-parameter Weibull function. The results show that the crystallite length of the mesophase pitch based carbon fiber K223HE is the longest, about 39.43 nm±2.63 nm, and that of HTA40 and T700SC PAN based carbon fiber is almost the same, about 4.63 nm±0.09 nm and 4.89 nm±0.06 nm, respectively. In the nano indentation load-depth curve, the residual deformation of K223HE is the biggest (75.34 nm±17.07 nm), indicating the lowest recovery ratio of indentation work (65.89%). The characteristic transverse elastic modulus of the three carbon fibers is 19.52 GPa, 11.99 GPa and 17.92 GPa. The Weibull modulus of the transverse elastic modulus of the three different carbon fibers (HTA40, K223HE and T700SC) is 25.26, 6.85 and 8.07, which displays the consistence in the properties of HTA40 is the best. The differences in the nano indentation behavior of the three carbon fibers are attributed to the differences in the integrity and preferred orientation of the crystallite of carbon fibers. 中国科学院战略性先导科技专项（XDA02040400）