Quantitative characterization of morphology of explosive welding interfacesbased on fractal theory

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 multi-fractal 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.