OBRABOTKAMETALLOV TECHNOLOGY Vol. 26 No. 1 2024 against the workpiece material being processed. The heat caused by these processes heats the chip material to a temperature of 350–450 °C [4, 5, 6, 7] (this temperature range is typical for milling aluminum alloys). The resulting heat spreads into the workpiece and the tool at a rate that largely depends on the physical characteristics of the material being processed [8, 9]. The heat distribution in the cutting area can be divided into two sections – the temperature on the front surface, depending on the feed, the geometry of the cutting blade (front angle, angle of inclination of the cutting edge, angle in plan, angle of elevation of the screw groove, etc.), and the temperature on the back surface, depending on the number of revolutions, the width of the chamfer in wearing process. The calculation of the contact temperatures on the front and back surfaces of the tool, as well as the cutting temperature of the cutting blade for milling aluminum alloys is based on: – changes in mechanical properties (ultimate strength, percentage of elongation) at increased test temperatures; – taking into account the combined eff ect of processes such as deformation and strain rate on the change in the value of the yield stress; – taking into account the thermal and physical characteristics of the material being processed (heat conduction and thermal diff usivity coeffi cients), as well as the density of the material. The temperature calculations during high-speed milling of aluminum alloys are of interest because temperature is a limiting factor in choosing a processing strategy. For example, when milling a wafer profi le inside a fuel tank for launch vehicles, it is not possible to use cutting fl uid. The thickness of the outer wall of the fuel tank is 2–3 mm [7, 10, 11]. In this milling process, the temperature on the surfaces of the cutting blade acts as a limiting factor, since its high values can lead to local warping of the structure [12, 13, 14]. It is not possible to control the temperature factor at production fi eld. Therefore, it is necessary to calculate rational milling modes in which the cutting temperature does not exceed acceptable values [9, 15]. In connection with the above, there is a necessity to develop a mathematical model for high-speed milling of aluminum alloys, which, as a fi rst approximation, takes into account the combined eff ect of temperature, strain rate and strain magnitude on the change in the yield stress of the processed aluminum alloy. The resulting model will make it possible to calculate temperatures on various surfaces of the cutting tool, as well as the cutting temperature in high-speed milling conditions, for cases where it is not possible to use cutting fl uid. The purpose of this paper is to develop a methodology for calculating the cutting temperature during high-speed milling of aluminum alloy workpieces. To achieve this purpose, it is necessary to solve the following tasks: 1) to create a defi ning equation for the specifi c work of deformation during cutting; 2) to solve the defi ning equation and fi nd its positions of extremum, which are heat sources; 3) to derive theoretical dependencies that allow calculating the temperature in the cutting zone during high-speed milling of aluminum alloy workpieces; 4) to conduct experimental studies to determine the cutting temperature at the specifi ed parameters; 5) to compare the theoretical and experimental data obtained and draw a conclusion about the accuracy of predicting the cutting temperature in a calculated way. Methods The defi ning equation for calculating temperature is the dependence of the change in the ultimate strength of the processed material on three constituent factors that arise during cutting (milling) – temperature, deformation and strain rate. Each of these factors will be considered separately and justifi ed. In conditions of small strain (for example, during tension or compression) andminor changes in temperature and strain rate, the change in yield stress can be described by the law of simple loading [16, 17]: ε σ ε σ ε 0 0 ( ) m T æç ö÷ ÷ = çç ÷ çè ÷ø , (1)
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