Investigation into Effect of Cutting Conditions on Surface Roughness while Dry Machining Al-11%Si and Al-11%Si-1% Bi Die Casting Alloy

Abstract

In this study, an experimental investigation was conducted to determine the effects of cutting speeds and feed rates on surface roughness in turning of the Al %11Si and Al-11%Si-1% Bi die cast alloys. Experimental trials carried out on a CNC machine using coated carbide inserts (PVD). Three different cutting speeds, 70, 130 and 250 m/min and three feed rates 0.05, 0.1 and 0.15 mm/rev were used with a 0.15 mm constant depth of cut for all experiments. Additionally scanning electron microscope (SEM) was employed to clarify the different types of silicon morphology. Results revealed that surface roughness increased with increasing feed rate from 0.05 to 0.15 mm/rev and decreased with increasing cutting speed from 70 to 250 m/min. The result showed that workpiece containing Bi had the best surface roughness with lamellar silicon shape in comparison with aluminium-silicon with flake-silicon shape.