Evaluation of friction energy in the overall energy balance of machining

The analytical relations that make it possible to determine the components of the cutting forces arising during the turning on the front and rear surfaces of the cutter and take into account the friction and cutting processes have been defined. It has been shown that taking into account the friction of the rear surface of the cutting tool against the material being cut results in the existence of minimum of the radial component of the cutting force as a function of the friction coefficient. In this case the minimum of the radial component of the cutting force is shifted towards the lower values of the friction coefficient with decreasing intensity, and increasing the rake (including both positive and negative values), which is true for both cutting and abrasive treatment. On the basis of analytical relationships cutting and friction energy in the overall energy balance of machining have been evaluated and the conditions to reduce the friction energy have been defined. The reliability of the theoretical solutions has been confirmed experimentally. It has been stated that with the cutting speed increase in turning the tangential and radial components relation increases due to the decrease in the intensity of friction on the rear surface of the cutting tool. As this takes place the angle of action that is equal to the difference of the conventional angle of friction of the material being cut and the front surface of the cutting tool and the rake angle decreases. This shows that the friction coefficient decreases with the increase in cutting speeds due to increasing temperature and cutting power in the overall energy balance of the turning process. Practical recommendations to improve the efficiency of the machining by reducing frictional energy have been made. The technique of computational and experimental determination of the parameters of the power intensity of the cutting process has been offered