Bioabsorbable composite laminates of PLA reinforced with surface‐modified Mg wires for orthopedic implant applications

Unidirectional and multidirectional laminates of Mg‐wire‐reinforced poly‐lactic‐acid–matrix composites are manufactured by an improved compression molding strategy that allows excellent control on the position and orientation of the wires. Two different types of Mg wires, with and without surface modification by continuous plasma electrolytic oxidation, are used, the former to improve the interfacial strength and to reduce the degradation rate of Mg wires in biological environments. The mechanical properties of the constituents as well as of composites are measured before and after in vitro degradation by immersion in simulated body fluids and the corresponding deformation, fracture, and degradation mechanisms are analyzed in detail. It is found that the presence of the Mg wires improves the mechanical behavior in tension and compression of unidirectional composites in the longitudinal direction (close to cortical bone) and that quasi‐isotropic laminates with tailored properties can be designed from the data of unidirectional composites.