ADHESION BONDING OF HYDROXYAPATITE WITH ADDITION OF ZIRCONIUM OXIDE ON Ti -6Al-4V ELI FOR ORTHOPAEDIC IMPLANT

The lack of adhesion bonding of a hydroxyapatite (HA) coating layer on the surface of an implant material can cause the coating layer to peel off during implantation and will increase the risk of metallic ion release into the human body and may also to increase the inflammatory effect and slow down the osseointegration process.In order to increase the adhesion of HA coated Ti-6Al-4V ELI, zirconia (ZrO 2 ) was added into the coating layer.The coating process of the HA suspension with addition of ZrO 2 on Ti-6Al-4V ELI sample surfaces was conducted by using dip-coating method.The samples were then heated to 800, 900, and 950 °C.The coating layer properties were then examined using a light microscope.The improvement in the adhesion bonding was correlated by calculating the removed area on the layer using the cross-cut tape test method and calculating the contact angle of the coating.The low value of the removed area and contact angle of the coating indicated the adhesion coating is good.The test specimen with the ZrO 2 addition has a lower removed area than the test specimen without the ZrO 2 addition.The value of the removed area also correlates with the obtained layer contact angle.The test specimen with the ZrO 2 addition has a lower contact angle (hydrophilic coating) than the test specimen without the ZrO 2 addition.The adhesion of this strong hydroxyapatite layer is good for improving the osseointegration.