A robust calcium carbonate (CaCO3) coating on biomedical MgZnCa alloy for promising corrosion protection

To improve the anti-corrosion property of biodegradable magnesium alloy , a CaCO 3 coating was developed by hydrothermal treatment . The prepared coatings generally consisted of three layers: a dark inner layer, a bright middle dense calcite layer and a bright outer loosely deposited CaCO 3 layer. As the electrolyte concentration increased, the formation of the inner product layer and the deposition of loose aragonite products were considerably inhibited, whereas the middle calcite layer became more intact and compact, which conferred enhanced corrosion protection upon the coated samples. Additionally, this coating showed a possible transformation into calcium phosphate during immersion.