TOOL-CHIP CONTACT LENGTH AND FEED INFLUENCE ON CUTTING FORCE

Abstract

This paper investigates the influence of cutting process parameters such as feed, cutting speed, depth of cut and tool-chip contact length on resultant force during machining of mild steel and aluminium alloys. Forty experiments were carried out on aluminium and mild steel alloys based on cutting parameters (feed rate, cutting speed and depth of cut). Experimental procedure invovoles measuring the lengths of chips that slide on the tool face (tool-chip contact length) at various combinations of cutting parameters. Results indicate that as the resultant force increased from 583N to 2037N at constant depth of cut (0.10mm) and cutting speed (47m/min), the contact length increased from 0.08mm to 0.58mm for Aluminium alloys. At higher cutting speed of 71m/min and 0.20mm depth of cut, lower force of 594N to 1483N was recorded giving rise to increased contact length of 0.62mm to 0.86mm. Higher values of contact length (0.08mm to 0.74mm) are obtained for mild steel as the resultant force increased from 1079N to 3111N at the same cutting conditions for aluminium. At higher cutting speed of 71m/min and 0.20mm depth of cut, lower force of 854N to 2193N were obtained for mild steel with contact length increasing from 0.78mm to 0.95mm. Therefore, tool-chip contact length decreases as feed rate increases and mild steel gives higher cutting force in machining process than aluminium alloys under the same cutting conditions.