Understanding the effects of excimer laser treatment on corrosion behavior of biodegradable Mg-1Ca alloy in simulated body fluid

Abstract

In this study, a KrF excimer laser was used to modify the biodegradable Mg-1Ca alloy and the time-evolution degradation behavior of the alloy before and after laser treatment was investigated in simulated body fluid (SBF) solution using immersion tests and electrochemical impedance spectroscopy (EIS). A 5 µm melted layer with a homogeneous microstructure and an MgO film on the surface were achieved by laser radiation. Corrosion observations (hydrogen evolution, morphology and corrosion products) and EIS results revealed an improvement of corrosion resistance after laser treatment for 48 h. It was found a two-layer structure developed after 2 h immersion on both the untreated and laser-treated alloys, but the sequence of forming the two layers was opposite and greatly influenced by the laser-treated layer. The time-evolution corrosion processes on the untreated and laser-treated alloys were discussed, providing a better understanding of corrosion behavior of biodegradable Mg alloys modified by excimer laser.

Keywords

• Magnesium
• Biodegradable implant
• Excimer laser
• Simulated body fluid
• Corrosion
• EIS