The Effect of Artificial Aging Treatment and Lubrication Modes on the Cutting Force and the Chip Surface Morphology when Drilling Al-Si-Mg (A356) Cast Alloys

This article reports the effects of various artificial aging methods and lubrication modes (dry, mist, wet) on the recorded cutting forces and chip morphology in drilling Al-Si-Mg (A356) cast alloys. In the course of this work, the work part sampled were as-received alloy (T0), solution heat-treated alloy (SHT) and then aged alloys at 155°C, 180°C, and 220°C (T4, T6, T61, T7), respectively. The significant effects of artificial aging the recorded cutting forces were noticed. Except minor cases under lower levels of feed rate, in general lower cutting forces were observed in A356-T0 and A356-T7 which are more brittle than other tested alloys. A direct relationship can be formulated among the microcracks on the free surfaces of the chips, brittleness and the recorded cutting forces. The use of MQL led to lower resulting cutting forces under similar cutting conditions. This can be related to less effect of thermo-mechanical stresses on the work part under MQL mode which tends to reduce the cutting forces.