An improved approach to manufacture CNT reinforced magnesium AZ91 composites with increased strength and ductility

TL;DR

This study enhances magnesium AZ91 composites by incorporating Pt nanoparticle-decorated MWCNTs, resulting in improved mechanical strength and ductility through better dispersion and wettability, supported by experimental and simulation analyses.

Contribution

It introduces a novel Pt nanoparticle coating on MWCNTs to improve their dispersion and interfacial bonding in magnesium composites, leading to enhanced mechanical properties.

Findings

Pt-coated MWCNTs improve composite strength and ductility

Enhanced dispersion stability of MWCNTs in Mg matrix

Uniform dispersion observed with Pt-coated MWCNTs

Abstract

Multiwalled carbon nanotubes (MWCNTs) are decorated with Pt nanoparticles by a "layer-by-layer" approach using poly (sodium 4-styrene sulfonate) (PSS) and poly (diallyl dimethylammonium chloride) (PDDA). Transmission electron microscopy (TEM) images and Energy Dispersive X-Ray (EDX) analysis of the samples confirm Pt deposition on surfaces of CNTs. Dispersibility and dispersion stability of MWCNTs in the solvents are enhanced when MWCNTs are coated with Pt nanoparticles. Mg AZ91 composites reinforced with MWCNTs are then produced by a melt stirring process. Compression tests of the composites show that adding 0.05\% wt Pt-coated MWCNTs in AZ91 improves the composite's mechanical properties compared to the pure AZ91 and pristine MWCNT/AZ91. Fracture surface analysis of the composite using a scanning electron microscope (SEM) shows individuals pulled out MWCNTs in the case of the Pt-coated MWCNT/AZ91 composites. We attribute this finding to the uniform dispersion of Pt-coated MWCNTs in Mg due to the improved wettability of Pt-coated MWCNTs in Mg melts. Molecular dynamics (MD) simulations of the interaction between Pt-coated MWCNTs and Mg support this interpretation.