Fabrication process optimization for improved mechanical properties of Al 7075/SiCp metal matrix composites

Abstract

Two sets of nine different silicon carbide particulate (SiCp) reinforced Al 7075 Metal Matrix Composites (MMCs) were fabricated using liquid metallurgy stir casting process. Mean particle size and weight percentage of the reinforcement were varied according to Taguchi L9 Design of Experiments (DOE). One set of the cast composites were then heat treated to T6 condition. Optical micrographs of the MMCs reveal consistent dispersion of reinforcements in the matrix phase. Mechanical properties were determined for both as-cast and heat treated MMCs for comparison of the experimental results. Linear regression models were developed for mechanical properties of the heat treated MMCs using list square method of regression analysis. The fabrication process parameters were then optimized using Taguchi based grey relational analysis for the multiple mechanical properties of the heat treated MMCs. The largest value of mean grey relational grade was obtained for the composite with mean particle size 6.18 µm and 25 weight % of reinforcement. The optimal combination of process parameters were then verified through confirmation experiments, which resulted 42% of improvement in the grey relational grade. Finally, the percentage of contribution of each process parameter on the multiple performance characteristics was calculated through Analysis of Variance (ANOVA).

Effect of B4C and SiC nanoparticle reinforcement on the wear behavior and surface structure of aluminum (Al6063-T6) matrix composite

“…These results imply that transfer and mechanical mixing of materials have taken place between the two sliding surfaces, and a mechanically mixed layer (MML) has formed in the darker areas on the worn surface. As a result, it seems that a mechanical mixing with oxidation process was responsible for wear resistance in the case of all composites [31].…”

“…These particles provide more sites for the nucleation of fine precipitates. These fine precipitates anchor lattice strain to deform the matrix to increase hardness and wear resistance of materials [31]. The T-6 heat treatment with an aging had a significant effect on wear resistance of composite [32].…”

Review on properties of aluminium metal matrix composites

“…Pugalenthi et al has said that aluminium metallattice composites are broadly delivered with various earthenware mixes as fortifications to improve their properties and to suit different auxiliary applications [24]. The present work includes the manufacture of Al7075 composites with silicon carbide (SiC) and aluminium oxide (Al2O3) as fortifications through mix throwing [24]. Four examples were delivered with various syntheses including SiC (3, 5, 7 and 9 wt%) and Al2O3 2 wt% in every one of the mixes.…”

Personnel selection with grey relational analysis

“…Tzeng et al (2009) optimized the performance of turning operations with Taguchi and GRA methods. Chen and Chen (2010) Das et al (2016) proposed to used GRA for optimizing the fabrication process of a metal matrix composites. Tripathy and Tripathy (2016) optimized the parameters of machining process in powder mixed electro-discharge machining with GRA and TOPSIS methods.…”