Investigations and regression modeling on mechanical characterization of cast aluminum alloy based (LM 26 + graphite + fly ash) hybrid metal matrix composites

Aluminium Hybrid Metal Matrix Composites (AHMMC) outperformed traditional materials in a variety of engineering fields such as aerospace, marine, and automobile parts due to improved properties such as strength and hardness. The reinforcements which will be added in the AHMMC will make significant contributions for improving the desired material properties. An exploratory study was conducted in this investigation on the development of aluminum-based (LM 26) hybrid metal matrix composites with reinforcements of Graphite and fly-ash. The composite is fabricated using the stir casting approach with various reinforcement combinations by different weight proportions (LM 26 85% and 15% Graphite + fly-ash). The fabricated composites are tested to determine their mechanical properties in accordance with ASTM standards. A comparative analysis was performed to determine the significance of reinforcement as well as the properties of composites at various weight percentages. The reinforcement combinations (LM 26 85% and 7.5% Graphite + 7.5% fly-ash) offers comparatively better mechanical properties with tensile strength 238 N/mm² and micro hardness 163.3 HV than the remaining combinations which are considered in this investigation. Microstructural analysis was also carried out to reveal the distributions of reinforcement and the nature of fractured surfaces. Wear behavior of the fabricated composite were analyzed by regression analysis and the results are presented.