High performance of coating hydroxyapatite layer on 316L stainless steel using ultrasonically and alkaline pretreatment

One of the metals used for bone implants is 316L Stainless Steel, which is succesfully coated with hydroxyapatite to increase its low biocompatibility. Therefore, this study aims to carry out sonication, alkali, and heating treatment on 316L Stainless Steel substrates, determine the effect of temperature (A) sonication time (B), acetone concentration (C), bidirectional interaction of sonication temperature and time (AB), bidirectional interaction of sonication time and acetone concentration (BC), bidirectional interaction of sonication temperature and acetone concentration (AC) and the three-way interaction of sonication temperature, time and acetone concentration (ABC), a suitable empirical model for the coating process, and concentration of cleaning solution on the bond strength of the hydroxyapatite layer. The empirical model of the bond strength of the hydroxyapatite layer used was y = 426.1 – 11.50A – 19.25B – 6.229C + 0.6505AB + 0.1944AC + 0.2737 BCE – 0.00933 ABC with an R2 value of 99.49%. The result showed that the layer's bond strength increases with the sonication temperature. It also showed that the longer the sonication time and the acetone concentration, the lower the bond strength value. The highest hydroxyapatite bond strength was produced at a sonication temperature, time, acetone concentration volume and bond strength of 45 °C, 15 min, 99%, and 91.35 Mpa, respectively.