Heat Treatment and Friction Stir Processing Effects on Mechanical Properties and Microstructural Evolution of Sc Inoculated Al-Zn-Mg Alloys

摘要

It has studied the influence of different artificial ageing parameters on Vicker’s hardness characteristics and friction stir processing on surface modification of scandium inoculated Al-Zn-Mg alloys. The aluminium alloys were solution treated at 465°C for one hour, quenched in water and artificial ageing at 120°C, 140°C, and 180°C at different time of ageing upto twenty hours. Further, friction stir processing healed the casting porosity and refine cast microstructures. These microstructural changes led to a significant improvement in both strength and ductility the aluminium alloys (7xxx series). Generally, high tool rotation rate is beneficial to break coarse second-phase particles, heal the casting porosity, homogenize and consequently increase strength. Therefore, friction stir processing is adopted to modify the microstructure of cast aluminium alloys to refine grain and enhance mechanical properties.