MgO-incorporated carbon nanotubes-reinforced Mg-based composites to improve mechanical, corrosion, and biological properties targeting biomedical applications

Abstract

In this study, magnesium oxide (MgO) nanoparticles are incorporated on carbon nanotubes (CNTs) to reinforce Mg–3Zn–1Mn alloy (ZM31 alloy) by semi-powder metallurgy, followed by hot extrusion, with the purpose of improving the mechanical and biological properties of Mg-based alloy. The microstructural analysis of the nanocomposites indicated a reduction in grain size of Mg alloy with the incorporation of CNTs with a maximum reduction of 61% (ZM31/CNTs), with further reduction in grain size (68%) detected when MgO integrated CNTs composites (ZM31/MgO-CNTs). The compression characteristics of the composites indicate an increase in ultimate compressive strength of 36% and 44%, respectively, with the incorporation of CNTs and MgO-CNTs fillers, and the hardness of Mg alloy increases by 37% and 58%, respectively, with the incorporation of CNTs and MgO-CNTs fillers. The strengthening mechanisms of Mg alloy composites reinforced with MgO-CNTs were discussed. Furthermore, MgO bounded CNTs fillers decelerated the degradation rate of Mg-based alloys, whereas the introduction of CNTs to Mg alloy had a less significant effect. Besides, the ZM31/MgO-CNTs composite indicated superior cytocompatibility because of its lower corrosion rates. According to the overall results, the outstanding mechanical performance, appropriate corrosion characteristics, and good cytocompatibility of the ZM31/MgO-CNTs composites verified their potential in medical fields.