Characterization of mechanically milled and spark plasma sintered Al2124-CNT nanocomposites

Abstract

In the present work, ball milling and spark plasma sintering were used to develop Al2124-CNT nanocomposites. The effect of milling time on the grain size and lattice strain of the ball milled Al2124 alloy powder and the effect of sintering time and temperature on the grain size of the matrix in spark plasma sintered Al2124 alloy and CNT-reinforced Al2124 nanocomposites were investigated. The density and hardness of the developed materials were evaluated as functions of the sintering parameters. It was found that ball milling not only reduced the particle size of the Al2124 powder but also decreased the grain size of the ?-aluminum phase to 50 nm and increased its lattice strain. A milling time of 6 hours was found to be the optimum time to reach a nanostructured ?-aluminum matrix. The grain size of the ?-aluminum phase in the sintered samples increased with increasing sintering temperature and time to reach maximum values at a sintering temperature of 500?C and a sintering time of 20 minutes. Although sintering led to grain growth, the grain size of the ?-aluminium matrix remained in the nanometer range and did not exceed 150 nm. The relative density and hardness of the sintered samples increased with increasing sintering temperature and time to reach maximum values at a sintering temperature of 500?C and a sintering time of 20 minutes.

Effect of Processing on Mechanically Alloyed and Spark Plasma Sintered Al‐Al2O3 Nanocomposites

“…The composite reinforced with 10% vol. of Al 2 O 3 nanoparticles displaced higher hardness than other aluminium based nanocomposites reinforced with CNTs [46][47][48] or SiC nanoparticles [33]. However, its hardness was lower than the hardness of Al-10 wt.% SiC nanocomposite [15] and Al5083-10 wt.% SiC [39].…”

Temperature-dependent thermal properties of spark plasma sintered alumina

“…Overall, the relative density of sintered samples increased with the increase in sintering temperature and sintering time to reach high value at 1400 °C and 10 min. This is due to the enhanced diffusion rate [28]. Therefore, the higher the sintering temperature and time, the higher the diffusion rate and the lower the remaining porosity.…”

Electron backscattered diffraction analysis of friction stir processed nanocomposites produced via spark plasma sintering

“…For this reason, low temperature and high pressure are indicated as optimal combinations in SPS of pure aluminium in order to retain nanostructure in the sintered material (Liu et al ., ,b). Maximum temperature has a direct influence on the sintered materials density (Saheb, ). Normally, with the same temperature and pressure an increase in density and hardness is recorded for SPSed Al‐based materials (Liu et al ., ; Milligan et al ., ; Saheb et al ., ).…”