Significantly enhancing the strength plus ductility combination of Mg-9Al alloy using multi-walled carbon nanotubes

In the present study, Mg-9Al/MWCNTs (multi-walled carbon nanotubes) composites were synthesized using the technique of powder metallurgy followed by hot extrusion. MWCNTs were dispersed in Mg-9Al matrix using an ionic gemini dispersant. Microstructural characterization studies revealed that MWCNTs can be individually dispersed with no structural damage. Matrix-MWCNT was found to be excellent (absence of voids and debonding). Results further revealed that the addition of MWCNTs significantly affected the size of Mg17Al12 phase, which decreased from micron to nano length scale. The tensile test results revealed that the elongation and ultimate tensile strength of Mg-9Al composite with 0.4 wt % MWCNTs content were 15% and 355 MPa, respectively, showing 150% and 18% enhancement in comparison to Mg-9Al alloy. The remarkably enhanced mechanical properties were mainly attributed to the uniformly distributed nanoscale Mg17Al12 s phase in composite and the excellent interface bonding between MWCNTs and matrix. (C) 2019 Elsevier B.V. All rights reserved.