Abstract
Magnesium alloys have been widely studied as biodegradable metals due to their low density and fast dissolution properties, making them a promising alternative for use as medical support implants. Their compatibility and degradation in the human body eliminate the need for a second surgery. However, magnesium alloys must maintain their mechanical integrity during the healing period. Despite their generally low corrosion resistance, they are highly susceptible to stress corrosion, which can lead to premature and sudden fractures of the implant. This susceptibility poses a significant challenge to their widespread use, underscoring the importance of analyzing their behavior in corrosive environments to understand their effects on mechanical properties and structural integrity. Computational modeling, particularly using "Digital Twin," plays a crucial role in orthopedic implant design, allowing for easier and faster optimization of the final shape based on criteria such as strength and stiffness, while ensuring compatibility with the bone healing process. This study aims to characterize and experimentally analyze the effects of stress corrosion on the WE43 alloy. Constant load tests were conducted using a portable and adaptable device equipped with compression springs to apply tensile force. Specimens were immersed in Simulated Body Fluid (SBF) to replicate the corrosive environment. A numerical corrosion model was developed to predict strength and mass loss, considering the effect of local stress on corrosion rate. The calibration of material model parameters was based on experimental results, with the numerical approach extendable to generic geometries. Consequently, the proposed numerical model proved to be an efficient tool for evaluating the structural integrity of biodegradable magnesium alloys and bone-implant assemblies, offering potential for use in designing optimized orthopedic implants. The study concluded that the simultaneous effect of stress and the corrosive environment (stress corrosion) was the primary cause of mechanical property loss.