In vitro tribological behavior of Mg2Zn1Mn/HA-Al ₂ O ₃ nano-biocomposites

Abstract Magnesium biocomposites reinforced with biocompatible ceramic particles are considered promising biomaterials for orthopedic applications due to their biodegradability and compatibility with bone regeneration. In addition to mechanical and corrosion performance, the in vitro wear behavior of these materials is critical for implant components subjected to frictional loading. In this study, the sliding wear behavior of Mg2Zn1Mn nano-biocomposites reinforced with hydroxyapatite (HA) and alumina (Al 2 O 3 ) nanoparticles was investigated under a 10 N load in both dry and simulated body fluid (SBF) environments. The influence of reinforcement content and sintering route (one-step and two-step) on wear performance was examined. The results revealed that wear losses were higher in SBF than in dry conditions, due to simultaneous corrosion-assisted wear, as well as the incorporation of 6 wt.% HA and Al 2 O 3 nanoparticles, together with two-step sintering, improved in vitro wear resistance by 33.9 %. Scanning electron microscopy analyses showed that abrasive and oxidative wear dominated under dry sliding conditions, whereas corrosive wear became the primary mechanism in SBF. These findings demonstrate that dual ceramic reinforcement significantly enhances the wear resistance of Mg2Zn1Mn biocomposites, particularly in physiological environments.