Evaluation of the parameters of titanium surface micro-pits on the titanium-PEEK joint fracture toughness

The present work is to investigate fracture toughness of titanium-PEEK by linking the interface fracture toughness to surface parameters of micro-pit on titanium panels during delamination. The relationship between geometrical parameters and failure mechanisms is also explained. The regular micro-pits were fabricated on pure titanium panels by Lithography. The effects of micro-pattern on fracture toughness were systematically evaluated by changing geometrical parameters of surface topography. The results showed that by changing the parameters of surface pattern, the fracture toughness can be manipulated through plastic deformation and molecular bond breaking of PEEK. The optimized wetting angle and surface free energy, having influenced on the real contact area and the stress regions, were obtained by adjusting the geometrical parameters. Finally, it was found that the failure mechanism transition from interface to cohesive was because of the attributed optimal parameters, showing more energy dissipation.