Enhanced ductility of Mg–3Al–1Zn alloy reinforced with short length multi-walled carbon nanotubes using a powder metallurgy method

Abstract

Mg-3Al-1Zn-CNTs composites, with different weight fractions (0.25-1.0 wt%) of carbon nanotubes (CNTs) were successfully fabricated via a powder metallurgy method. The processing parameters were adopted in such a way to have uniform dispersion of short length CNTs without any damage, as well as refined and dissolved β phases structures throughout the composite matrix. The composite exhibited impressive increase in microhardness (about þ23%) and tensile failure strain value (about þ98%) without significant compromise in tensile strength, compared to the un-reinforced Mg-3Al-1Zn alloy. The synthesized composites can be used in automotive and aerospace industries due to their low density and high specific strength.

Metallurgical Challenges in Carbon Nanotube-Reinforced Metal Matrix Nanocomposites

“…The initial volume fraction of incorporated CNTs, formation of intermetallics, and quality of the formed interface between the Mg and nanotubes are the important factors in determining the mechanical properties of the nanocomposites. It is shown that an increase in the initial amount of incorporated CNTs may promote the refinement of coarse grains and enhance the failure strain [146,147]. Figure 22 shows the evolved microstructure of CNT-AZ31 nanocomposites produced using the disintegrated melt deposition technique followed by hot extrusion.…”

“…The formation of a clean interface with no impurity or defect is shown to improve the mechanical properties [144]. A recent study by Rashad et al [146] showed that the formed intermetallics in MWNTs-dispersed Mg-3Al-1Zn alloys are refined with the CNTs inclusion. Figure 23 indicates the schematic demonstration of Mg17Al12 generation at the interface of Mg-3Al- Similar to CNT-Al and CNT-Ti binary systems, the precipitation of the mentioned intermetallics may bilaterally affect the mechanical properties of CNT-dispersed Mg matrix nanocomposites.…”

“…A schematic view of Mg17Al12 particles formed in Mg-3Al-1Zn/MWNTs nanocomposites prepared by powder metallurgy method. The incorporation of MWNTs can drastically refine the particles (β phase corresponds to Mg17Al12) [146]. (Reproduced with permission from [146], Elsevier, 2015.…”

“…The incorporation of MWNTs can drastically refine the particles (β phase corresponds to Mg17Al12) [146]. (Reproduced with permission from [146], Elsevier, 2015. ) A review on the literature confirms that recent research works have strived to attribute the enhanced properties of CNT-Mg composites to the formation of different intermetallics.…”

Microstructure, Tensile Properties and Hardness Behavior of Al7075 Matrix Composites Reinforced With Graphene Nanoplatelets And Beryl Fabricated by Stir Casting Method

“…[12][13][14][15]. Graphene incorporation into aluminum matrix reports in enhancement of hardness, and tensile strength [16][17][18][19][20]. Graphene nanoplatelets (GNPs) are known to be multilayer Graphene.…”