Role of hybrid reinforcement on microstructural observation, characterization and consolidation behavior of AA 6061 nanocomposite

Abstract

The present investigation had dealt with the synthesis, characterization and consolidation behavior of AA 6061 nanocomposites reinforced with hybrid (TiC+Al2O3) nanoparticles with varying weight percentages (0.0, 0.5, 1.0, 1.5 and 2.0wt.%) prepared by 30h of mechanical alloying (MA) and compared with 2wt.% of various reinforcements such as titanium carbide (TiC), multi-walled carbon nanotubes (MWCNTs), gamma phase alumina (γ-Al2O3) nanoparticles. The microstructure, grain size, lattice strain and lattice parameter of the above powders were examined using different analysis techniques including X-ray diffraction (XRD) analysis, scanning electron microscope (SEM), transmission electron microscope (TEM) and energy dispersive spectrometry (EDS). The compressibility and sinterability of the prepared nanocomposites at varying sintering temperatures and varying compaction pressures were also studied. Consolidation behavior in terms of particle rearrangement and plastic deformation mechanisms were evaluated by Balshin, Heckel, Panelli and Ambrosio Filho and Ge linear compaction equations. The effect of hybrid and nanolevel reinforcements on mechanical properties such as green compression strength, Vickers hardness and density of nanocomposites were evaluated. Among the above nanolevel reinforcements, hybrid (TiC+Al2O3) and TiC nanoparticles gave maximum green compression strength (211 and 233MPa) and maximum hardness (985 and 1186MPa) for 2wt.% addition to AA 6061 matrix after 30h of MA.