Effect of Specimen Thickness and Compositions on the Fracture Toughness Investigations of Al7075-SiC/Al2O3 Hybrid Composites

Abstract The current work is to examine the effect of the parameters like specimen thickness, crack length to width ratio and composition of the reinforcements used in aluminium-silicon carbide/alumina particulate composite. The said composite is processed using the stir casting route. Taguchi's optimization techniques such as experiments, ANOVA and regression techniques have been utilized to investigate the parameters. Three factors and their levels considered are the composition of reinforcements (3, 6 and 9 wt%), the thickness of specimen (10, 12, 15 mm) and a/W ratio (0.45, 0.47 and 0.50). Results show increment in composition beyond 6wt%, and a/W ratio decreases the fracture toughness of hybrid composites. From Taguchi's analysis, for a/W ratio = 0.45, 12mm thick specimens and 6wt% of reinforcements in aluminium matrix exhibit the larger fracture toughness. Thus those parameters are considered to be optimized parameters. The analysis shows that the a/W ratio influences fracture toughness, followed by the composition and specimen thickness.