Coating of Stainless Steel 304 Surface with Apatite Compound Using the Electrophoretic Deposition Method

Abstract

Stainless steel 304 is a metal used to replace damaged bones. However, this metal has a low level of biocompatibility in the body. To solve this problem, the metals are coated with a biocompatible material before implantation. The material used to coat the stainless steel is an apatite compound derived from eggshell because the composition of minor minerals of eggshell was CaCO3 94%, MgCO3 1%, CaPO4 1%, and organic material 4%. The method used in this research is the electrophoretic deposition method. This research aims to study the effect of apatite compounds that are coating on stainless steel 304 surfaces. Based on the experimental results, the suspension process carried out pH controls that resulted in pH 11.15, 1.42, 3.86, and 4.55. Increasing and decreasing pH can occur because the compound of HNO3 and NH4OH was strong acid and base. Researchers were not very careful in measuring the volume of HNO3 and NH4OH when it was inserted into the apatite compound suspension. The pH of the suspension affected the potential value (ζ), which indicated the stability of the particle resistance and determined the direction and speed of migration during the EPD process. Using the apatite compound concentration affected the mass of apatite compounds deposited on the stainless steel 304. Based on the experimental results, apatite compounds can attach to the stainless steel 304 surface.