Effect of nickel coating on steel wire reinforcement on mechanical properties of aluminum matrix composites produced via lost foam casting

In this study, an aluminum alloy, A356, was reinforced with the interconnected, two-dimensional, steel wire preforms. Steel wires were coated with nickel by electroless deposition method. The composites were produced by lost foam casting process. Three different wire volume fractions were used (5.77, 10.90 and 17.66 percent). Hardness test and tension test were conducted on aluminum alloy and composite specimens, and the microstructure of the specimens was examined with optical and scanning electron microscopes. Micro structural characterization conducted on the composite samples showed good interfacial integrity. Hardness and strength of composites increased as compared to matrix alloy. The mechanical properties of these composites were measured and the results were correlated with the microstructure observation. It was found that nickel-coated steel wire reinforced composites show considerable improvement in strength with good ductility because nickel form a good interface between Al matrix and steel wire. Uncoated steel wire reinforced composites showed improvement in strength to a lower extent possibly because of formation of brittle intermetallic compound at the interface. Fracture surface of tensile specimen was examined under SEM. Nickel coating on steel wire improved the strength properties while retaining a high level of ductility due to better interface bonding.

کلیدواژه ها:

Aluminum matrix composite ، Nickel coating ، Mechanical properties ، Lost foam casting ، Steel wires