Effect of Nano ZrO2/Fly Ash Particles on Hardness of AA7178 Metal Matrix Composites Using Novel Encapsulate Stir Casting Technique

This study compares the hardness level of as-cast AA7178 with a reinforced hybrid metal matrix composite fabricated with fly ash (5%) and nano zirconium oxide (ZrO 2 ) (5%) hybrid composites using a novel encapsulation technique. The samples for both groups were created using a novel encapsulating process employing the stir-casting method. For group 2, a hybrid composite of fly ash (5%), nano ZrO 2 (5%), and AA7178 was used, whereas AA7178 as-cast was used for group 1. The samples were made following ASTM E92 criteria, and their hardness was measured using a Vickers hardness machine. Each group with 20 samples was fabricated. The G-power used for this process is 80%, α = 0.05 per set for calculating sample size and the total sample size is 40. The maximum hardness of the (5% and 5%) fly ash and nano ZrO 2 filled material is 35.61% greater than the as-cast AA7178. T-test statistical analysis reveals a significant p = 0.00 (p < 0.05) difference in the mean-variance of hardness between groups 1 and 2. Within the constraints of this study, it was observed that adding 5% fly ash and 5% nano ZrO 2 reinforcement with AA7178 composite significantly enhances hardness.