Degradation and Friction Mechanism of Magnesium Alloy in Simulated Human Body Fluid

Magnesium metal has good biological properties and can rapidly degrade until it completely disappears after being implanted into the human body. However, due to its active chemical properties, magnesium is prone to oxidation reactions with human body fluids, leading to rapid corrosion and unable to meet the requirements of a certain degradation cycle for intramedullary nails. Especially after bearing, the friction corrosion coupling effect may further accelerate its degradation rate. Through observation of corrosion morphology, corrosion rate testing, electrochemical polarization curves, and friction and wear tests, a comprehensive analysis was conducted on the biological rate and friction and wear properties of pure magnesium and magnesium alloys in simulated human body fluid (SBF). The results show that the corrosion rate of magnesium alloy in simulating human body fluids was reduced by 50% compared to pure magnesium, about 3.98 mm/a. Under dry friction conditions, the friction coefficient of magnesium alloy slightly decreased compared to pure magnesium, and the wear amount was also significantly reduced. In the SBF medium environment, the corrosion of both materials was mainly oxygen corrosion, and the main factor determining the corrosion rate was the anodic polarization process.