Patterns of formation and reduction of cutting temperature at machining

Abstract

The paper proposes a new theoretical approach to determining the cutting temperature at blade cutting. Its essence lies in the fact that in the design scheme of the cutting process, based on the representation of the removed allowance as a package of elementary straight-line adiabatic rods that are cut by the cutting tool, it is necessary to take into account the number of generated shear elementary volumes of the material being processed that affect the cutting temperature. In fact, it is necessary to change over from taking into account the continuous nature of cutting the adiabatic rod to the discrete nature of its cutting. The calculations stated that with an increase in the number of the resulting shear elementary volumes of the material being processed, the cutting temperature increases. Therefore, under real cutting conditions it is necessary to strive to reduce them in order to reduce the cutting temperature and to improve the quality and productivity of processing. This is achieved by blade cutting, since cutting of elementary adiabatic rods is basically continuous at grinding and the cutting temperature takes on the greatest values. Thus, it has been shown that when turning Steel R6M5, the cutting temperature is just slightly higher than the cutting temperature at turning Steel 45, although Steel R6M5 is several times stronger than Steel 45. Based on the calculated cutting temperature scheme proposed in the work, this may be due to a decrease in the number of the resulting shear volumes of the processed material when turning Steel R6M5 and, accordingly, with an increase in their thickness, which contributes to an increase in the nominal shear angle of the material being processed and a decrease in the conventional stress cutting, i. e. helps reduce power and heat intensities of the cutting process. Consequently, the solution proposed in this paper makes it possible to substantiate the effectiveness of the transition to finishing operations from the grinding process to modern methods of cutting with the aim of reducing the cutting temperature and improving the quality of the surfaces to be processed. Practical recommendations for further improvement of blade processing methods have been developed on the strength of this work