Effect of Nickel Alloying and Mechanical Stirring on the Microstructure and Mechanical Properties of Al – 10% Si – 5% Cu Alloy

The effect of nickel additions on the microstructure and ultimate tensile strength of alloy Al – 10% Si – 5% Cu in cast and heat treated conditions is studied. The nickel content optimum for obtaining a maximum-strength alloy is determined. The conditions at which a fishbone morphology negatively affecting the mechanical properties does not form are determined. Mechanical stirring of the melt before crystallization is shown to affect positively the strength and the structure of the alloy.