Strengthening of the magnesium matrix composites hybrid reinforced by chemically oxidized carbon nanotubes and in situ Mg2Sip

Aggregation and weak interfacial bonding limit the superior strengthening potential of the carbon nanotubes (CNTs) in the metal matrix composites. To overcome these challenges, in situ Mg2Si nanoparticles (Mg2Sip) have been hybridized with surface modified CNTs through chemical oxidization. The synergistic strengthening was enhanced by tailoring the volume ratios of CNTs to Mg2Sip in the Mg matrix through powder thixoforming technology. Herein, when 0.3CNTs-1.2Mg(2)Si(p) was added, a yield strength, ultimate tensile strength, and elongation of 213 MPa, 271 MPa, and 6.3%, respectively, were obtained, which were 18.3%, 16.8%, and 3.3% higher than those of the 0.75CNTs-0.75Mg(2)Si(p)/Mg composites, respectively. The strengthening effects of the CNTs-Mg2Sip reinforcements were more effective than those of the individual 1.5CNTs and 1.5Mg(2)Si(p) owing to the effective thermal mismatch and load transfer strengthening mechanisms. In this study, we propose an effective approach to harness the superior performances of the hybrid reinforcements for enhancing the composites. (C) 2020 Elsevier B.V. All rights reserved.

Automated summary

Surface modified CNTs were hybridized with in situ Mg2Si nanoparticles through chemical oxidization to enhance the synergistic strengthening in Mg matrix composites. The tailored volume ratios of CNTs to Mg2Sip using powder thixoforming technology resulted in improved mechanical properties. The strengthening effects of the CNTs-Mg2Sip reinforcements were more effective than using individual CNTs or Mg2Si nanoparticles.