Investigation of Hardness and Microanalysis of Sintered Aluminum-Based Supplemented Metal Matrix Machined Composites

Abstract

Aluminum metal matrix composites (AMMCs) have become increasingly ubiquitous in the fields of aerospace and automobile businesses due to their lightweight properties. Their machining is a challenging task because of the presence of supplemented particles, also called reinforcements. As the wt% of the supplemented particles changes, the morphological and machining behaviors of the AMMCs change. The present work is focused on exploring the thermo-mechanical properties of AMMCs which would help in AMMC applications in the aerospace industry with a new collection of composites containing silicon carbide (SiC) and zircon/zirconium silicate (ZrSiO4) as supplements in wt% of 5%, 20%, 30%, and 40%. Uniform binary and hybrid sample pallets are prepared by powder metallurgy (PM). The said samples are sintered and then machined using wire electric discharge machining (WEDM) employing brass wire with a feed rate of 2 to 3 mm/min. Also, analysis of porosity and recast layer formation is performed via the microstructure, scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS). Some interesting and useful findings are obtained which can extend the applications of AMMCs in automobiles and the aerospace industry. The results reveal that temperature and wt% are playing their significant roles in the changes in the thermo-mechanical properties of AMMCs. Mathematical equations via regression analysis using Minitab 17 and Excel are developed for the congruence of experimental data. Analysis of Variance (ANOVA) is also performed. Hence, the most optimized relationships for the best machining output are established and presented in this proposed study.

Keywords

• aluminum metal matrix composites
• analysis of variance
• electric discharge machining
• regression analysis
• scanning electron microscopy