A novel contact area based analysis to study the thermo-mechanical effect of cutting edge radius using numerical and multi-sensor experimental investigation in turning

[Display omitted] •A multi-sensor approach to estimate the thermo-mechanical load on the cutting tool due to varying edge radius and feed is presented.•The effects of nose radius, edge radius, major and minor cutting edge are delineated through a novel contact area based analysis.•Changing the radius and feed alters the chip formation, chip morphology, forces and temperature.•Numerical simulation is used to estimate the effect of edge radius on the stagnation zone in front of the tool.•The ideal cutting edge radius is predicted for different feeds − 0.1 mm/rev − 18 μm; 0.24 mm/rev − 33 μm; and 0.41 mm/rev − 43 μm. The micro-geometry of the cutting tool significantly affects the process forces, thermal load, tool wear, and quality of the finished surface and chip characteristics. The effect of edge radius on the thermo-mechanical load for varying uncut chip thickness is studied during turning AISI 4340. A multi-sensor approach is used to measure the temperature at the flank face, the average temperature of the chip in the cutting zone and also at the free surface of the chip simultaneously by using a thermocouple, a thermal camera and a pyrometer respectively. A novel tool-chip contact area based analysis is used to delineate the effect of hone radius and nose radius separately. The major and minor cutting edge contact areas along the hone region are found to play a key role in influencing the process forces and temperature at different feeds. FEM simulations are conducted to study the effect caused by edge radius on the material flow in the stagnation and ploughing zones. Also, a linear regression analysis is carried out to predict the ideal cutting edge radius for different feeds used in this study − 0.1 mm/rev − 18 μm; 0.24 mm/rev − 33 μm; and 0.41 mm/rev − 43 μm. The results from this experimentation could be used by researchers to validate their temperature models and develop more accurate temperature maps of the tool.