Microstructure And Mechanical Properties of Ultrasonically Processed Al-7Si Alloy / Y2O3 Nanocomposite
Abstract The aim of the present study is to investigate the microstructure and mechanical properties of the A356 aluminum metal matrix composite reinforced with Y2O3 particles. The composite is synthesized by adding 1 and 2 vol.% of reinforcement via stir casting assisted by ultrasonic treatment (UT). Microstructural contemplates shows improvement in the dispersion of nano Y2O3 particles and decrease in the porosity level due to the ultrasound aided synthesis. The UT refines the size of the Y2O3 particles as well as helps to improve its dispersion. The secondary dendrite arm spacing of 2 vol.% Y2O3 reinforced samples with 5 min UT is found to be significantly reduced to 12 µm as compared to that of the as-cast A356 alloy. Addition of 2 vol.% of nano Y2O3 has significantly improved the hardness of the A356 alloy from 60 HV to 108 HV. A considerable increment in the YS and TS of the A356 alloy is observed with the of Y2O3 and found to further improve with UT. However, small reduction in ductility is observed with the addition of Y2O3 as well as ultrasonic treatment.