Developments of Calcium Sulfate Coating on Ti6Al4V Substrate by Flame Spray

The purpose of this study is to create a ceramic-metal composites to accelerate the recovery after implanting. Calcium sulfate is a degradable bio-ceramics used widely as bone filler in current. It has good biocompatibility, no toxicity, osteoconductivity and abundant as well. In this study, calcium sulfate coating was successfully prepared on the Ti-6Al-4V substrate by flame spraying technique, and each property of the coating was analyzed. The results showed that the bonding strength between substrate and calcium sulfate coating prepared by flame spraying could reach 37.02 MPa. The average porosity of the coating was 18.9% and the porous structure led the coating to rapid degradation and collapse. In the degradation test, the accumulated weight loss of the coating soaked in Hank’s solution reached 100% on the fifth day. Besides, the high temperature of flame spray caused the calcium sulfate to decompose into calcium oxide and led the pH value of the SBF to rise to 12 after 1 day of immersion. The power of flame spray was then lower to avoid the calcium oxide to appear. The pH value of the SBF after 1 day of immersion dropped to 11.3.