Effects of hydrothermal coating on the degradation behavior and biocompatibility of an Mg–4Zn–0.3Sr alloy

Abstract

• A crack-free and compact Mg(OH) 2 coating was obtained by hydrothermal coating. • The coating significantly improved corrosion resistance of the Mg–4Zn–0.3Sr alloy. • Cell attachment and viability were improved by the application of coating. Hydrothermal method was applied to create a protective coating on the Mg–4Zn–0.3Sr alloy, using de-ionized water (as precursor) for different synthesizing times of 3, 4, 5, and 6 h. XRD and EDS line-scan confirmed formation of Mg(OH) 2 coating. Based on the surface morphological appearance, 5 h coating time at 160 °C was found to be the optimum condition. The corrosion current of the coated sample decreased from 2.58 to 0.48 µA/cm 2 in the uncoated condition. Also, the biocompatibility assessments using Alamar blue test showed that the cell viability and cell attachment to the formed Mg(OH) 2 coating are more pronounced in comparison with the uncoated alloy.