Abstract
This paper investigates the effect of alloying elements, namely, Sn, Fe, and Mn, and drilling tool materials with a standard geometry on the machinability of heat-treated hypoeutectic. B319.2 and near-eutectic 396 alloys. The results reveal that the 396 alloy displays the most rapid increase in the total drilling force and moment with an increase in the number of holes drilled. The differences in machining behavior of the 396 and B319.2 alloys may be attributed mainly to the variation in the silicon content, 10.8%Si and 7.5%Si, respectively. The addition of 0.15% Sn to the 396 and B319.2 alloys has a beneficial effect on the tool life of the different drills used. The presence of sludge in the 396 alloy resulting from the addition of 0.25%Fe and 0.25%Mn, leads to an extremely rapid increase in the total drilling force and moment and has an unfavourable effect on tool life. A visual examination of the chips reveals that the fan shape is by far the predominant form during the drilling of the alloys studied. Also, the fan shape, due to its compact size and shape, is the ideal chip for most drilling applications.