Comparative Study on Metallography and Mechanical Properties of Al–Cu–Ni/FeNb Composites Fabricated by Electromagnetic Stir Casting Processes via Sand and Metal Mold System

A systematic comparative correlation between the as-cast microstructure and mechanical properties of Al5Cu2Ni/ x FeNb ( x = 1, 3, and 5%) composites is fabricated by a two-step electromagnetic stir casting technique via sand, and metal mold system has been investigated. The metallography of the composites was captured and examined with optical microscopy and scanning electron microscopy (SEM) with energy dispersive x-ray spectroscopy. It was observed that the addition FeNb master alloy along with Ni alloy to Al-5Cu base alloy leads to the formation of fine grain structure (fine α-Al dendrites) due to the formation of intermetallic compound phases of Al 2 Cu, Al 3 Ni 2 and heterogeneous Fe 2 Nb phase which are acts nucleation sites. The porosity of the composites by metal mold was much lower than the sand mold, which is less than 4%. Hence, it is acceptable for fabrication. The mechanical properties of the Al5Cu2Ni composite could enhance significantly with the addition of FeNb particulate reinforcement. However, the monotonic increment was found at 5 wt% of FeNb particulate reinforcement. FESEM fractography revealed that the micro-cracks, voids, dimples and nature of the failure.