MODELING OF THE TEMPERATURE DISTRIBUTION ON THE LATHE FRONT SURFACE TAKING INTO ACCOUNT GEOMETRIC PARAMETERS OF THE SECONDARY PLASTIC ZONE

Abstract

The study objective: modeling of the temperature distribution along the front surface of the lathe cutter for a given moment of the cutting system evolution. The problem to which the paper is devoted. To evaluate the influence of the geometric parameters of the secondary plastic zone of on the characteristics of the temperature distribution for the front surface of the lathe cutter. Research methods. Geometric parameters of the plastically deformed layer are defined by digital modeling of contact processes by the finite element method. Some initial data for computer modeling and subsequent verification of its results are carried out on the basis of a full-scale experiment with longitudinal turning of a work piece made of stainless steel 12X18H9T with a T15K6 solid-alloy plate. The novelty of the work. Prediction of the temperature on the cutter front surface for a given moment of the cutting system evolution based on a scientific approach of using hydrodynamic analogies to the evaluation of deformation processes in the machined material and combined data of a full-scale and digital experiment. The study results. By means of a digital experiment, the boundaries of the secondary plastic zone in the chip are determined, then a temperature distribution curve is made on the cutter front surface in two variants: for variable and for a constant average thickness of the deformed layer. It is found that the average value of the contact temperature in both cases differs slightly and agrees well with the results of the full-scale experiment. The difference between the maximum temperature values is significant: with a variable layer thickness, the calculated temperature is 11% lower than for the variant with a constant value of this parameter. Conclusions: to calculate the average temperature in the secondary plastic zone, the average value of the deformed layer thickness can be used. In the case of solving problems related to determining the maximum temperature in the cutting zone, it is advisable to take into account the change in the thickness of the plastically deformed layer in the chip along the cutter front surface.