Fracture Surface Morphology and Roughness of Ti-Scaffold Filaments

Titanium scaffolds produced by additive manufacturing were studied using the scanning electron microscopy (SEM) and the confocal optical microscopy (COM). The previous research has shown that the titanium scaffolds with porous filaments (14 % porosity) exhibited markedly better fatigue resistance than those with compact filaments (6 % porosity). This article is devoted to macroscopic and microscopic images of fracture surfaces of both types of scaffolds after cyclic compression (CC) tests and after cyclic three-point bending tests (CTPB). A high density of cracks and broken filaments was indicated particularly in scaffolds with porous filaments. The fatigue crack growth was highly affected by the microporosity. Fracture facets were smaller and rougher for the porous filaments compared to the compact ones. Values of roughness parameters S a and S v for porous filaments were significantly higher than those for compound fibres. Both SEM and COM studies confirmed an important role of crack-pore interactions especially in the porous filaments.