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7444 |
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Improvement of the adhesion strength of bioactive glass coatings obtained by Atmospheric Plasma Spraying |
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Beatriz Garrido / University of Barcelona, Spain Irene Garcia-Cano / University of Barcelona, Spain Sergi Dosta/ University of Barcelona, Spain |
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Orthopedic devices need to be modified to be bioactive, in other words to stimulate the bone to regenerate and create a good bonding in the implant surface. Bioactive glasses are interesting materials due to their resemblance to the mineral part of the bone and are used as coating material onto metallic implants. Due to the difference of coefficient of thermal expansion (CTE) between the metallic substrate and bioactive coating material, it is difficult to ensure enough adhesion of the coating. The aim of this study is improving the adhesion strength of bioactive glass coatings to achieve adequate values to be used in orthopedic implants. To reach this goal two different approaches were considered: first increasing the interaction among particles and with the substrate, for this purpose agglomerated bioactive glass powders were used. Second strategy is based on using a material with higher affinity with the substrate, for this aim different blends of hydroxyapatite (HA) in combination with bioactive glass were designed. In this study, 45S5 bioactive glass coatings were produced by Atmospheric Plasma Spray (APS) onto titanium alloy substrates. The coatings have been characterized in terms of microstructure, adhesion and bioactivity. It was found that a significant improvement in adhesion strength is obtained for the developed coatings, particularly when agglomerated powders are used which accomplish the values required for being used in orthopedic applications. |