Effect of Reinforcement on Compacting Characteristics of Aluminum/10-Al₂O₃/Fly Ash Metal Matrix Composite

Aluminum metal matrix composites are attractive and effective materials because of their unique properties. These properties include high specific strength, light weight, high specific stiffness, excellent wear resistance, good corrosion resistance, and greater elastic modulus compared with the base alloy. They are used in aerospace, automotive, marine, mining, and mechanical structures. Fly ash, an inexpensive waste by-product obtained after the combustion of coal in thermal power plants, is considered as a reinforcement particle in the present study. The aim is to investigate the effect of fly ash in Al-10 weight percentage (wt%) aluminum oxide (Al₂O₃) metal matrix composites using statistical optimization techniques. One factor and Taguchi approaches are used in planning and designing the experiments. Al/10 wt% Al₂O₃ with 0, 5, 10, and 15 wt% fly ash composites are prepared with the powder metallurgy technique at 300, 400, and 500 MPa compaction pressure with 90, 120, and 150-μm fly ash particle sizes. The wt% of fly ash, compaction pressure, and particle size are the process parameters. Performance parameters such as ejection force and green density, hardness, and compressive strength are considered. The ejection force and green density decreased with the increase in the weight percent of fly ash. Hardness increased with the increase in fly ash content. Compressive strength increased with the increase in fly ash up to 5 wt% and subsequently decreased.