扫描电镜下断口表面的三维重建及分形维数的测量

3D Reconstruction and Fractal Dimension Measurement of a Fracture Surface under SEM

基于数字散斑相关方法,利用扫描电镜立体对技术和计算机视觉方法实现了物体表面的三维重建,讨论了影响其精度的原因,并且利用分形理论对表面的三维形貌进行了定量分析,由立方体覆盖法得到了三维形貌的分形维数。作为应用的实例,将该方法应用到岩石断口的三维重建中,得到了重建后的高度云图和分形维数。结果表明,利用扫描电镜立体对技术对断口表面进行三维重构并进行分形维数的计算是一种行之有效的断口定量分析方法。这为研究材料断裂的微观机理、断裂过程和断裂性质等问题提供了一种途径。

Based on the digital speckle correlation method, a 3D reconstruction technique of a surface is achieved by combining SEM（scanning electron microscope）stereo image pairs with computer vision theory. The factors that affect result＇s precision in this process are discussed. A quantitative analysis of the obtained 3D surface can be carried out by employing fractal theory. Fractal dimension of the reconstructed 3D surface is measured by an improved cubic covering method. As an illustration of the technique, a rock facture surface 3D reconstruction was carried, and contour and the fractal dimension of the rec.onstructed 3D surface were obtained. Results indicate that the proposed 3D reconstruction by combining SEM stereo image pairs with computer vision theory is an effective method to quantitatively analyze fracture surface. Thus, it will provide an approach to study microscopic fracture mechanism, fracture progress and fracture characters of materials.