Laser surface structuring of Ti6Al4V substrates for adhesion enhancement in Ti6Al4V-PEEK joints

Abstract

PEEK is a promising polymer possessing high mechanical strength and biocompatibility and therefore it can be associated to titanium for biomedical applications. This study aimed at producing Ti6Al4V-PEEK joints with enhanced adhesion through laser-structuring Ti6Al4V treatments. Ti6Al4V cylindrical substrates were prepared by two types of surface treatments: alumina blasting and laser structuring. The holes number and size in laserstructured surfaces was varied. PEEK was then hot pressed against the metallic substrate to completely filling the surface cavities. The adhesion of the PEEK/Ti6Al4V joint was assessed by a shear bond strength test. Fracture surfaces and interfaces were investigated by SEM/EDS. Significant differences were found in the shear bond strength between alumina blasted and laser-structured samples. Bond strength improvement (exceeding 300%) was registered for the laser-structured specimens relative to grit-blasted ones. The laser-structuring technique showed to be very promising in the production of specifically designed surfaces for high strength andmechanically stable Ti6Al4V/PEEK joints.