Effect of heat treatment on microstructures and mechanical behavior of porous Sr–Ca–P coatings on titanium

Titanium and its alloys are widely used in dental and orthopedic fields due to their excellent chemical stability. The micro-arc oxidation (MAO) technique is an effective method for coating strontium, calcium, and phosphorus onto titanium. In clinical application, the adhesion between the coating and the substrate is important factor for dental implants and artificial joint prosthesis. The present study investigates the effects of heat treatment on the properties of MAO coatings. The physicochemical characteristics are investigated using scanning electron microscopy (SEM) observation, thin film X-ray diffraction (TF-XRD) analysis, and the scratch test. After heat treatment, the TF-XRD results indicate that the tricalcium phosphate phase appears at a temperature of 800 °C. SEM results show that the surface morphology does not change. The scratch test results reveal that the adhesion strength between the coatings and the substrate increases with increasing heat treatment temperature. Consequently, all findings in this study indicated that MAO coatings with heat treatment have good mechanical properties for clinical applications.

► We used an efficient technique to coat porous Sr-Ca-P coatings on titanium. ► The heat treatment method accelerates mechanical properties and crystallinity of the coatings. ► After heat treatment at various temperatures, all specimens show the same morphologies. ► Adhesion strength between the coating and the substrate increases with increasing heat treatment temperature. ► The heat treatment is beneficial method for improving coatings adhesion in medical applications.