A study of fracture mechanics for compact tensile specimen of Al6061-SiC metal matrix composite.

The main contribution of the present work is the display of the impact of the addition of SiC into the aluminum alloy Al6061. For this reason, the Mode I stress intensity factor K_I and T-stress for compact tension CT specimen are evaluated using 3D finite element analysis (FEA). The material used here in the compact tension CT specimen is Al6061-SiC metal matrix composites reinforced with various volume fractions of 4%, 6%, 10%, 12%, and 14% of SiC particles. Three different crack lengths (a/H) ratios of 0.35, 0.43, and 0.5 are considered through the analysis. Only half of the model of the cracked compact tension CT specimen with a subjected load of a magnitude P = 603 N is analyzed, and K_I, T₁₁-stress, and T₃₃-stress are computed. From the FEA results, it is observed that the K_I, T₁₁-stress, and T₃₃-stress are mainly influenced by the volume fractions of reinforced SiC particles. A more significant decrease in the values of K_I, T₁₁-stress, and T₃₃-stress is found in the Al6061-14vol.%SiC composite CT specimen. Where FEA results of K_I for the Al6061-14vol.%SiC composite CT specimen exhibited reduction percentages of 5.4%, 5.6%, and 5.7%, respectively, for (a/H) = 0.35, 0.43, and 0.5, as compared to those of Al6061. FEA values of T₁₁-stress for the Al6061-14vol.%SiC composite CT specimen reduced by 5.5%, 5.6%, and 5.7%, respectively, for (a/H) = 0.35, 0.43, and 0.5, respectively, over those of Al6061. Also, the decrement percentages of FEA results of T₃₃-stress for the Al6061-14vol.%SiC composite CT specimen over those of Al6061 were found to be 17.1%, 16.6%, and 16.5%, respectively, for (a/H) = 0.35, 0.43, and 0.5, respectively. Overall, fracture mechanics properties are improved by the addition of SiC particulates into the Al6061 alloy.