Hydroxyapatite based on Abalone Mussel Shells Coating on Titanium Alloy using Electrophoretic Deposition Dip Coating as a Bone Implant Candidate

Abstract In this study, hydroxyapatite (HA) from abalone mussel shells (Haliotis asinina) is synthesized using the precipitation method with a stirring time of 30 min and a calcination temperature of 1000°C. HA was used for coating Ti alloy using the electrophoretic deposition dip coating (EP2D) method. The coating applied three variations, including the DC voltages variation of 25 V and 50 V, the withdrawal speeds of 0.1 mm/s, 0.5 mm/s, 1 mm/s, and the calcination temperatures of 750°C and 950°C. Energy dispersive X-Ray spectroscopy (EDS) revealed the Ca/P molar ratio of HA was 1.63, which is close to the stoichiometric ratio of HA at 1.67. The distance between the crystal planes of the HA was 2.81Å. This result also is relative to the crystal plane of the HA at 2.88Å. The EP2D process and the calcination temperature treatment will remove the B-type carbonate apatite phase, so the purity of the HA layer is higher. SEM results show that the HA layer formed was more homogeneous and thicker at the DC voltage of 50 V and the withdrawal velocity of 0.1 mm/s. At this voltage and velocity, minor cracking and agglomeration were produced. The density of the HA layer was higher with increasing calcination temperature and DC voltages. Keywords: Hydroxyapatite, Titanium Alloy, Coating, Electrophoretic Deposition Dip Coating