Adhesion strength characterization of PVDF/HA coating on cp Ti surface modified by laser beam irradiation

► Titanium substrates are superficially treated by laser beam irradiation. ► Treated titanium substrates are coated with α-PVDF and α-PVDF/HA films. ► Three-point bending test is used to assess the adhesion strength of coatings. ► The coatings show good physical adhesion on treated titanium substrates. ► Three-point bending test appears as an alternative for measuring adhesion strength. Up to the moment, there is no standardized test for measuring the adhesion strength of polymeric coatings on titanium substrate modified by laser beam irradiation. The present work aimed to assess the adhesion strength of polyvinylidene fluoride (α-PVDF)/hydroxyapatite (HA) composite coating on commercially pure titanium (α-cp Ti) substrate surface modified by laser beam irradiation, using the three-point bending test. The preparation of coating was carried out by mixing α-PVDF pellets dissolved in dimethylacetamide (DMA) with HA/DMA emulsion. The mixture was poured onto the α-cp Ti sample and left to dry in an oven. Commercially pure titanium plates were coated with α-PVDF/HA composite film, in proportions of 100/00 (PVDF) and 60/40 (PVDF/HA) in weight. The Ti-PVDF/HA samples were subjected to the three-point bending test and analyzed by scanning electron microscopy. According to the results, PVDF and PVDF/HA coatings showed a good adhesion strength on α-cp Ti surface, since no detachment was observed.