Al Alloy Nanocomposite Reinforced with Physically Functionalized Carbon Nanotubes Synthesized via Spark Plasma Sintering

Nanocrystalline Al-11.5Si (in wt%) powders were prepared by high-energy ball milling of microcrystalline Al-Si powders, which were subsequently mixed with pristine and physically functionalized multiwalled carbon nanotubes (MWCNTs) separately and were consolidated by spark plasma sintering. Improvement in MWCNT dispersion was observed as a result of functionalization, which resulted in improved densification of the nanocomposites (NCs). Scanning electron microscopy was performed to understand the agglomeration and dispersion of CNTs. Distribution of MWCNTs, the dislocation activity, and the effect of primary Si particles in NC matrix were studied by carrying out transmission electron microscopy. Nanoindentation was performed to measure the elastic modulus and microhardness of the NCs which showed appreciable improvement for functionalized MWCNT reinforced NC.