Medium-dependent corrosion behavior of magnesium alloy wires: Transition from uniform corrosion in simulated intestinal fluid to pitting corrosion in Hanks’ solution

Magnesium alloy wires hold great promise for biomedical applications due to their excellent biocompatibility and degradability. However, their rapid corrosion in physiological environments severely restricts their clinical use. This study examines the corrosion behavior of Mg-Zn-Nd-Zr wires in simulated intestinal fluid (SIF) and Hanks’ solution, revealing that SIF induces uniform corrosion (4.53 mm/year) via unstable MgHPO 4 ·3H 2 O layers, while Hanks’ solution triggers severe pitting (1.65 mm/year) due to Cl - induced breakdown of the protective CaHPO 4 ·2H 2 O/CaHPO 4 layer. Scanning electronic microscope and X-ray photoelectron spectroscopy analysis confirm distinct corrosion mechanisms, providing critical insights for optimizing alloy performance in different physiological settings-surface modification for SIF and Cl - -blocking coatings for Hanks’-like environments. These findings offer a quantitative and theoretical foundation for developing corrosion-resistant magnesium-based medical devices. 1. Comparative study on corrosion mechanisms of Mg-Zn-Nd-Zr alloy wires. 2. Focus on ultrafine Mg-Zn-Nd-Zr alloy wires with a diameter of 0.23 mm. 3. Early-stage corrosion behavior and mechanisms of Mg alloy wires (30 s - 5 h).