基于峰值力纳米力学模量成像技术的碳纤维/树脂复合材料界面尺寸与性能的原位表征

为准确测定复合材料界面结构的尺寸与性能,提出一种原位峰值力纳米力学模量成像(PF-QNM)技术,对其测试原理、校准方法和适用性进行分析,并采用PF-QNM技术对碳纤维/聚醚醚酮(T300/PEEK)、碳纤维/聚醚砜(T300/PES)和碳纤维/环氧树脂(T700/TR1219B)三种复合材料的界面尺寸和各组分原位模量进行测试。结果标明:该方法的横向分辨率可以达到纳米尺度,测得树脂、界面、纤维区域的弹性模量数值呈梯度上升趋势,区分度明显,T300/PEEK、T300/PES和T700/TR1219B复合材料界面厚度分别为(69.3±7.9)nm、(101.3±10.2)nm和(48.4±5.4)nm。实验范围内,热固性复合材料界面厚度小于热塑性复合材料。对模量成像图统计分析可得,T300/PEEK、T300/PES和T700/TR1219B复合材料的树脂区平均弹性模量分别为4.36 GPa、4.96 GPa和3.59GPa,与其宏观弹性模量数值较为接近。

In situ characterization on dimensions and properties of the interphase in carbon fiberreinforced polymer composites by peak force quantitative nano-mechanics technique

In order to quantitatively characterize the interphase of carbon fiber reinforced polymer composites, in situ peak force quantitative nano-mechanics (PF-QNM) technique was introduced.Its general principles, calibration method and applicability were analyzed.PF-QNM technique was used to measure the interphase dimensions and in situ modulus of each component of carbon fiber/poly-ether-ether-ketone (T300/PEEK), carbon fiber/poly-ether-sulfone (T300/PES) and carbon fiber/epoxy (T700/TR1219B).The results show that this technique can determine the width and elastic modulus of the interphase in nanoscale lateral resolution.The gradient increases of modulus exist in the three composites from the matrix region to carbon fiber region.The interphase thicknesses of T300/PEEK, T300/PES and T700/TR1219B are (69.3±7.9)nm,(101.3±10.2)nm and (48.4±5.4)nm, respectively.In this study, the interphase thickness of thermoset composites is smaller than that of thermoplastic composites.The statistical analysis shows that the average modulus of resin matrix of T300/PEEK, T300/PES and T700/TR1219B are 4.36 GPa, 4.96 GPa and 3.59 GPa, respectively, which is close to their elastic modulus in bulk materials.