Combining fractal and topological analyses to quantify fracture surfaces in additively manufactured Ti-6Al-4V

Quantitative fractography has been hindered by the lack of tools capable of accurately characterizing fracture modes and crack initiation locations. An easily implementable, non-destructive image analysis-based tool utilizing fractal and topological techniques was developed to overcome these traditional shortcomings. With this tool, feature complexity, heterogeneity, and connectivity are quantified through the calculation of fractal dimensions and lacunarity and topology measurements, respectively. Validation of this tool was performed on complex fatigue fractures in additively manufactured Ti-6Al-4V, with fracture initiation sites at near surface, sub-surface, and internal defects and fatigue fracture modes being easily differentiated.