• • Corrosion fatigue in 5% NaCl reduces the fatigue strength of extruded AZ80-T5 and AZ31 Mg alloys by 40–70% compared with air, with fatigue limits falling to 40–70 MPa at 10^7 cycles; this premature mechanical failure directly threatens the structural integrity of load-bearing orthopedic implants and cardiovascular stents.
• • Flow-induced shear stress exceeding approximately 1 Pa in microfluidic and cardiovascular test systems disrupts the passivation film on Mg alloys, increasing degradation rates by up to 3-fold relative to static immersion; this threshold defines the hydrodynamic condition under which stent struts and flow-exposed implants lose mass at clinically unacceptable rates.
• • Phase-field and peridynamic models capture pit-to-crack transitions in biodegradable Mg alloys with damage localization driven by secondary phases, enabling prediction of SCC initiation sites at the micrometer scale; such models reduce reliance on costly and time-consuming in vivo trials during alloy screening.
• • Surface treatments including plasma electrolytic oxidation (PEO) on AZ61 Mg alloy alter fatigue performance, with PEO coatings introducing brittle layers that can reduce fatigue life by 20–50% depending on coating thickness and defect density; this trade-off between corrosion protection and fatigue resistance must be resolved for clinical adoption.