Mechanical and damping behavior of artificially aged Al 6061/TiO2 reinforced composites for aerospace applications
Olusegun Adebayo Ogunsanya, Abayomi Adewale Akinwande, Oluwatosin Abiodun Balogun, Valentin Romanovski, M. Saravana Kumar
Abstract
In this research, the microstructural and mechanical properties of the as-cast and artificially aged Al6061-TiO2 alloy and its composites developed by the double stir casting process were studied. The reinforcements were added in different weight concentrations and artificial aging was done at 200 °C for 2 h. TiO2 particle reinforcement was adopted because of its better grain refining capacity, high elastic modulus and precipitate pinning effect. Heat treatment was performed for the formation of a high density of fine precipitates which was suitable for stress-bearing applications. The results showed an improvement in the tensile strength and hardness of the heat-treated samples up to 195.2 and 43.68%, respectively, compared to the as-cast samples. After TiO2 addition and age-hardening heat treatment, the SEM fractography showed that the small size dimples were evenly distributed which represented the enhanced ductile nature. The as-cast alloy and its composites had better damping properties compared to the age-hardened specimens. Fracture toughness and elongation showed enhancement in the heat-treated samples than in the as-cast samples. This enhancement is associated with the grain refining effect of TiO2 particles and precipitate formation. Artificially aged Al6061 alloy and its composite showed a better balance of properties.