Thermal history analysis and structure-property validation of friction stir welded Al-7079-TiC in-situ metal matrix composites

摘要

In the present study, Friction stir welding (FSW) of 6.5 mm thick cast Al-7079-TiC in-situ composite was obtained at 708, 931, 1216 rpm and 40 mm/min respectively. Microstructural characterization of FSWed joints revealed a homogeneous distribution of TiC reinforcements inside the dynamically recrystallized (DRZ) zone. Heat input required for different rotations were analyzed through a coupled study of thermo-mechanical analysis. Heat input was calculated by considering partial sticking and sliding conditions induced between tool and work piece. Transverse and longitudinal tensile test of the weld sections has been conducted. Grain morphology, heat input and TiC particle reinforcement distribution under different tool rotation has been analyzed and has been further correlated with micromechanics approach to validate the mechanical properties of the FSWed specimen. The predicted results have shown a good agreement with the experimental values. Hardness profile has shown a minimum of HAZ among all weld and an average maximum in the DRZ. The weld joint at 931 rpm has exhibited superior mechanical properties as compared to the joints welded at 708 and 1216 rpm respectively. (C) 2019 Elsevier B.V. All rights reserved.