FESEM制备高频正交光栅新方法及在复合材料跨尺度力学性能测试的应用

Cross gratings have been an effective carrier for electron beam moiré method, grid method and geometric phase analysis method to measure deformation. The deformation measurement sensitivity is directly proportional to the grating frequency, and the measurement accuracy is strongly affected by the grating quality. Thus，it is crucial to produce high-quality high-frequency cross gratings conveniently and efficiently on the sample surface that is to be measured. In this project, based on the raster-scanning process of the common field emission scanning electron microscopy (FESEM), an efficient method for preparing with frequency greater than 10,000 lines / mm and high quality cross gratings will be proposed. It will provide a practical and effective technology to fabricate cross gratings for experimental mechanics method to measure the deformation. And the fabricated cross gratings will be applied to measure the residual stress of the interface and the interlayer of the carbon fiber reinforced resin matrix composites. The strain distribution near the interface and the interlayer, the strain field around the defects and the strain concentration around the fracture fiber for composite laminates will be tested using electron beam moiré method combining geometric phase analysis method under the load. These studies will provide an effective tool for characterizing the cross-scale properties of the composite.

正交光栅是电子束云纹法、网格法以及几何相位分析法等测量变形的有效载体，其频率和质量直接影响测试结果的灵敏度和精度。因此在试样表面方便、高效制备出高质量的高频正交光栅已成为变形测试的关键。本项目基于普通场发射扫描电子显微镜（FESEM）的栅格式扫描成像过程，拟提出一种高效制备频率大于10,000线/mm，高质量正交光栅的FESEM栅格扫描制栅方法。为实验力学位移测量提供实用、有效的制栅技术。并拟将其应用到电子束云纹法和几何相位分析法中，“跨尺度”研究碳纤维增强树脂基复合材料界面和层间细纳观残余应力分布以及宏观载荷作用下界面和层间的应变分布、缺陷周围应变场、以及纤维断裂引起的应变集中等测试中，为复合材料细纳观力学性能“跨尺度”表征提供有效的工具。

正交光栅是电子束云纹法、网格法以及几何相位分析法等测量变形的有效载体。本项目对制备正交光栅的电子束感光胶细观力学性能以及与基体的结合强度进行系统研究，得到了不同固化温度下，不同厚度感光胶的硬度、模量以及与基底的结合强度的变化规律，为精确制备微纳米结构以及防止显影、定影过程中感光胶脱落提供理论依据。并基于普通场发射扫描电子显微镜（FESEM）的栅格式扫描成像过程，提出了高效制备频率为10000线/mm高质量正交光栅的FESEM栅格扫描制栅法，对其在Si基体制备高频光栅的曝光参数以及光栅质量进行了研究。同时利用该方法在复合材料以及不锈钢表面成功制备了不同频率的正交光栅，同时结合电子束云纹技术以及几何相位分析技术系统研究了碳纤维增强树脂基复合材料不同纤维铺层内界面纳米尺度下的残余应力分布规律以及SiC纤维增强Ti基复合材料界面强度、摩擦应力、摩擦系数以及界面残余应力分布等。同时将该方法应用于不锈钢冲击后细观变形场研究中，得到了冲击位置不同方向的残余塑性应变分布规律并与有限元模拟结果符合较好。

内容获取失败，请点击重试