Fabrication of 6061 aluminum alloy reinforced with Si₃N₄/n-Gr and its wear performance optimization using integrated RSM-GA

Abstract

In this research work the dry sliding wear behavior of a hybrid aluminum metal matrix composite is evaluated. Al 6061 is used as a matrix material while Si3N4 and nano-graphite powder (3-15 wt.%) are used as reinforcements. These two reinforcements (50 wt.% of each) were blended in high energy ball mill for homogeneous mixing to get the sound aluminum matrix composite (AMC). The hybrid composite is made by stir casting route and its wear rate was investigated against an EN32 steel disc surface, using a pin-on-disc tribometer. Integrated Downloaded by [University of Cambridge] at 22:30 13 June 20162 response surface methodology (RSM) and genetic algorithm (GA) are used to optimize the pinon-disc process parameters. Analysis of variance (ANOVA) shows that sliding distance plays a major role on the dry sliding wear rate followed by load, sliding speed and reinforcements. Twofactor interactions and quadratic terms have also significant contributions. Genetic algorithm suggested a minimum wear rate value of 0.827 mg at optimized setting. Micro-structural analysis by scanning electron microscopy (SEM) reveals that very fine grooves are obtained at optimized settings while at other settings severe ploughing is observed. Transition of wear mechanism takes place with the increase of speed (i.e., temperature between the two rubbing surfaces) from abrasive to adhesive.

Parametric study on the dry sliding wear behaviour of AA6082–T6/TiB2 in situ composites using response surface methodology

“…This decrease in wear was associated with the higher microhardness as the reinforcement content increased. An increase in hardness in the composites expectedly lowered the material removal rate in the composites, and thereby reduced the wear [30]. However, this trend was found to be relatively small when compared with those of other factors.…”

Experimental Evaluation of Mechanical, Wear and Corrosion properties of AA5083/Graphite Metal Matrix Composite Prepared using Compocasting Process

“…Graphite affords lubrication fallout and dwindle the friction and wear in the course of sliding. But a larger content of Gr can manage more advanced wear rate by virtue of the devaluation in fracture strength of AMCs [15]. Graphite also improves the dimensional stability.…”

Silicon Nitride as a Reinforcement for Aluminium Metal Matrix Composites to Enhance Microstructural, Mechanical and Tribological Behavior

“…4(f)-(g) shows rich interfaces between matrix and reinforcement. Microstructure images by Sharma et al [50] reported that, there were a uniform dispersion of Si3N4 and nano graphite particles in AA6061 alloy while the composite is fabricated via stir casting route. Amigo et al [51]…”