Experimental study of the combined influence of the tool geometry parameters on the cutting forces and tool vibrations

The aim of the experimental investigations was to select the optimal proposed cutting tool geometry by studying the effects of the tool angles (tool back rake angle (γp)) and the cutting edge angles (the tool cutting edge angle of the major cutting edge (κr) and cutting edge inclination angle (λs)) and there interrelations, which produces less-generated cutting forces, less tool vibrations, and improved machined surface roughness for turning operations. Different cutting tool geometries were designed according to the main tool angles and manufactured with a high speed steel material (HSS) type-T15 with a high tungsten alloy grade. Based on measured cutting force components, tool vibrations, and surface roughness, it can be concluded that when the γp angle ranges from a negative value (γp = −5°) to a positive value (γp = 0° and γp = 5°), the average cutting force components decreased, especially tangential force component (Fz) that was more remarkable, and tool vibrations reduced; this decreasing trend improved surface roughness. The effects of the variation of the κr angle and the positive λs angle were observed on the variation of the axial and radial force component, whereas the tangential force remained constant. Lowering κr decreased the surface roughness, while the λs angle increased, a small variation was observed. As a conclusion, the good optimized cutting tool geometries were classified as follows: the first was cutting tool geometry having a neutral angle (γp = 0°), the second was with γp = +5°, and then the third was with γp = −5°. Thereafter, the fourth tool geometry was having λs = 3° and the last was for geometry having κr = 75°.