Microstructure, wear resistance, corrosion behavior, and cytotoxicity of Mg-Zn-Ca amorphous coatings fabricated by laser surface melting

To address the issues of rapid degradation rate in biodegradable magnesium alloys, which seriously restricts their clinical application, this study employed laser surface melting (LSM) on Mg-Zn-Ca alloys. The impact of the LSM process on the microstructural characteristics of magnesium alloy was examined. Subsequently, an assessment was conducted to analyze the hardness, corrosion resistance, friction and wear properties, as well as cytotoxicity of amorphous coatings applied on magnesium alloy for potential use in biodegradable implants. When the laser scanning power was set at 500 W and scanning speed was adjusted to 90 mm/s, the LSM alloy exhibited good comprehensive of properties, with a microhardness of 540 HV and a friction coefficient of 0.2024. Electrochemical analysis conducted in simulated body fluid (SBF) solution revealed that the LSM sample demonstrated favorable resistance to corrosion, as evidenced by a corrosion potential of -1.3346 V, corrosion current density of 0.0199 mA/cm2, and corrosion rate of 0.455 mm/y. Both the cast and LSM alloys exhibited non-toxicity towards SaOS2 cells, with the LSM alloys displaying slightly superior biocompatibility than the as-cast alloys.