The effect of the substitution of silicon by aluminium on the mechanical properties of gray iron

Gray iron, a Fe-C-Si alloy, is one of the most common ferrous alloys used in the metal casting industry. Silicon is required to avoid metastable solidification (cementite). While small additions of Al may promote the pinholes or a greater amount of slag, several investigators have examined the influence of Al as a potential substitute for Si in gray iron [1,2] and in compacted graphite iron [3-6]. It was documented that higher percentages of Al alter the microstructure of gray cast iron, producing some potential benefits, including increased strength, reduced chill and lower hardness. This article investigates the effect of aluminum additions as a substitute for silicon, focusing on producing gray iron with high tensile properties.