基于分维理论的爆炸焊接界面形貌的定量表征

Quantitative characterization of morphology of explosive welding interfaces based on fractal theory

以爆炸焊接界面形貌为研究对象,利用分形理论研究其界面特征。运用三维超景深显微镜获得界面形貌图像,利用Matlab图像分析技术对界面形貌进行二值化处理,基于分形理论计算图像分维值以及多重分维谱。由分维值及多重分形谱的物理意义可知,轮廓分维值是对界面不规则程度宏观度量,而多重分形谱能定量表征界面的起伏程度及高度分布。因而,通过对界面结构进行分形几何分析,可实现界面形貌定量表征,弥补当前定性分析的不足。

Explosive welding interface structure determines the quality of composite materials.However,analyses on the interfaces morphology so far remain limited on the qualitative level and quantitative analysis methods have not been well established.In our work we took explosive welding interface morphology as research subject,extracted the fractal dimensions and multi-fractal spectrums of interface based on the fractal theory to understand its morphological characteristics.First,we obtained the interface structure by three-dimensional ultra-depth microscopy.Then we dealt with it by picture analysis techniques to gain its binary image.Furthermore,we calculated the fractal dimensions and multifractal spectrum of the images by fractal geometry.Following the fractal theory,the fractal dimension is the macroscopic characteristics of the welding interfaces and the multi-fractal spectrum reflects their degree of fluctuation and the ratio of distribution.Thus taking fractal dimension and multi-fractal spectrum into account when describing welding interface structure can make up for what is lacking in the qualitative analysis and achieve the quantitative analysis.