Microstructural and corrosion rate evolution of Mg-Nd-Zr alloy during multiaxial forging processing

Bioresorbable magnesium alloys represent a promising class of materials for temporary osteosynthesis implants; however, their clinical application is limited by excessively rapid degradation rates. This study investigates the effect of severe plastic deformation via multiaxial forging («abc»-pressing) on the microstructure, microhardness, and corrosion behaviour of an Mg-Nd-Zr system alloy (Nd–3.0 wt.%, Zr–0.4 wt.%, Zn–0.2 wt.%) for biomedical applications. Deformation processing was performed at 350°C with up to 9 cycles. Microstructural characterisation was conducted using optical microscopy and scanning electron microscopy with energy-dispersive spectroscopy. Corrosion behaviour was evaluated by potentiodynamic polarisation in 0.9% NaCl solution simulating physiological conditions. Multiaxial forging induced grain refinement from 56±21 μm to 48±18 μm after 5 deformation cycles, accompanied by transformation of the continuous intergranular Mg₁₂Nd β-phase network into uniformly distributed spheroidised particles. Decomposition of the supersaturated α−Mg solid solution resulted in Nd depletion of the matrix (from 2.2 to