Production of high performance AA7150-1% SiC nanocomposite by novel fabrication process of ultrasonication assisted stir casting

• Published in: Ultrasonics sonochemistry 2019-11, Vol.58, p.104665-104665, Article 104665
• Main Authors: Madhukar, Pagidi, Selvaraj, N., Gujjala, Raghavendra, Rao, Chilakalapalli Surya Prakasa
• Format: Article
• Language: English
• Subjects: AA7150; Aluminium metal matrix; Double stir casting; Nanocomposite; Silicon carbide; Ultrasonic
• ISSN: 1350-4177; 1873-2828
• DOI: 10.1016/j.ultsonch.2019.104665

•A novel fabrication process was successfully developed and compared with existing double stir casting technique.•Grain refinement was observed more 24 μm (64.7% reduction) as compared with double stir casting process (29 μm) and base alloy material (68 μm).•Novel fabrication process shows significant improvement in mechanical properties.•Tensile strength enhanced to 26.05% as compared to base alloy and 19.56% as compared to double stir casting process.•SEM photographs of fracture surface of nanocomposites confirm the mixed kind of ductile and brittle failure mechanism. The effect of ultrasonic vibration treatment on nanoparticle distribution was successfully investigated and developed a novel fabrication process to produce nano silicon carbide particle reinforced AA7150-1% SiC nanocomposite through a combination of the vortex, double stir casting, and ultrasonic vibration techniques. Ultrasonicfrequency of 20 KHz and with a power capacity of 1000 W was used in the process. Ultrasonic probe was used for proper mixing of the nanoparticles in the molten bath. Microstructure investigation of grain formation, particle distribution, and fracture surface was analyzed through an optical and scanning electron microscope at the as-cast condition. Energy dispersive spectroscopy was used for determining chemical composition of the nanocomposite. In the novel fabrication process, the influence of sonication effect on material properties such as porosity, microhardness, tensile strength were examined and compared with double stir casted nanocomposite material as well as the base material. Mechanical properties of AA7150-1% SiC novel fabrication process were enhanced with a reported increase of 26.05% in tensile strength, and 10.85% in microhardness. 74.1% reduction in porosity as compared to the base alloy. In the double stir casting process, there was 19.6% increase in tensile strength, 2.9% of improvement in microhardness, and 46.96% reduction in porosity as compared to base material properties. The enhancement of material properties with the ultrasonic probe assisted novel fabrication process are attributed to grain refinement of composite and homogeneous distribution of SiC nanoparticles due to the acoustic streaming and cavitation effect.