The influence of grain size on the corrosion characteristics of ZX10 biodegradable magnesium alloy in Hanks' solution

Magnesium alloys have long been a focus of aircraft designers due to their light weight and high strength. A relatively new application for magnesium alloys is self-dissolving (biodegradable) medical implants. Such implants do not require repeat surgery for their removal, which means reduced risks to the patient's health and a shorter recovery period. Since resorption in the human body is essentially a corrosive process, it is the corrosion characteristics that are the subject of detailed study. This paper examines the corrosion properties, such as the depth of corrosion damage, corrosion rate, and the stages of passivation film formation, of ZX10 alloy with different grain sizes: coarse-grained (as cast) and fine-grained (extruded). It was found that grain refinement contributes to a decrease in the corrosion rate, most likely due to the formation of a more continuous passivation film. Furthermore, damage on coarse-grained material is deeper and covers a significantly larger area compared to fine-grained material.