Beschreibung:
ABSTRACT : Magnesium alloy, a biocompatible and biodegradable material, is investigated as a promising material for the implants. In this study, aiming at implanting the components in the human body, the Mg-3Zn-0.2Ca composite with 0.6wt.% nano-sized MgO (Magnesium oxide) is processed by equal channel angular processing (ECAP) with the Route B C at 300 ℃. The evolutions of microstructure and mechanical properties during ECAP display that the grains turn to be homogenized significantly, which leads to that the compressive strain of facture (CSF) of the composites is increased from 14.10% to 34.18%. With the increase of ECAP passes, the added MgO and second phases turn smaller and distribute more evenly in the matrix due to the functions of dynamic recrystallization and mechanical shearing. Meanwhile, the preferred orientation of recrystallized grains contributes to the improvement of mechanical properties. The ECAP-ed specimens exhibit a higher corrosion potential and polarization resistance as well as the smallest corrosion current density, which shows better corrosion resistance. These findings demonstrate that by increasing the pass of ECAP of the Mg-3Zn-0.2Ca composite added 0.6wt.% nano-sized MgO can improve the mechanical properties and corrosion resistance, which is beneficial to its application in the biomedical industry