CoCr alloy is mostly used as biomaterial implant. However, it still has several weaknesses. Therefore, it is necessary to modify the surface to improve its biocompability. This research is a preliminary study on CoCr coated with Hydroxyapatite (HA)/Zirconium Dioxide (ZrO2) using Thermal Flame Spray method. 5 % - 20 % ZrO2 was mixed with HA. Besides improving the biocompatibility, ZrO2 is believed to be able to enhance the antibacterial properties. Characterization test was performed using FE- SEM. The coating was analyzed for corrosion rate, surface roughness and antibacterial activity. Adding ZrO2 to HA has been proven to be able to improve corrosion rate. Combination of 80HA-20ZrO2 is the most effective bioceramic mixture, producing lowest corrosion rate of 0.213 mm/year in HBSS media. This is due to the increased reactivity value and better passivation reaction than CoCr without coating. Antibacterial activity test revealed that the coating could form inhibitory area around the sample meaning that the coating can provide bacterial resistance for the implant.
Keywords: biomaterial; CoCr alloys; hydroxyapatite; zirconium dioxide; thermal flame spray, corrosion rate