Influence of forging on mechanical properties of Ni–P coated Si3N4 reinforced Al6061 composites

Ni–P coated silicon nitride reinforced Al6061 composites were fabricated by liquid metallurgy route. The percentage of silicon nitride as a reinforcement was varied from 4 wt% to 10 wt% in steps of 2. The developed cast composites were hot forged at a temperature of 500 °C. Both as cast and hot forged alloy and their composites were subjected to microstructural studies, micro hardness and tensile strength tests. Results reveal that, microhardness, yield and tensile strength of the developed composites are higher when compared with that of matrix alloy under both as cast and hot forged conditions. Increased content of silicon nitride in the matrix alloy leads to enhancement in micro hardness yield and tensile strength of the composites. However, the ductility of the cast and forged composites decreases with increased content of silicon nitride in the matrix alloy. Hot forged alloy and its composites possess higher microhardness, tensile strength and ductility when compared with the cast composites for a given reinforcement content.