OBRABOTKAMETALLOV technology Vol. 25 No. 2 2023 cutting tool and the workpiece. The ongoing processes lead to the cutting tool rapid wear and to a decrease in the quality of the workpiece being processed. The elimination of negative factors in metal cutting is ensured by the rational choice of processing modes, cutting tools and the supply of coolant to the cutting zone. However, the rational choice of coolant at production site is not given due attention. At the same time, it is known that different coolants, due to different properties, have different effects on the cutting process. Machine tests are required for selecting a coolant that provides the required quality of the workpiece being processed, the longest period of durability of the cutting tool and high productivity of the processing [1–5]. However, such tests require a lot of time and expenditures for the most efficient cutting tools and coolant purchasing. In turn, laboratory tests are quite economical and require much less time than machine tests. Therefore, in order to develop a methodology for accelerated evaluation of the lubricating properties of a coolant, it was decided to carry out laboratory tests instead of machine ones. Despite the advantages of laboratory tests, in the course thereof, it is not possible to reproduce all the conditions that arise during metal cutting. During such tests, not the entire process is simulated, but only some of its elements that have the greatest impact on the cutting process [5–16]. However, reducing the negative impact of even one factor can lead to a positive effect when cutting itself. Based on the scientific literature about coolants, it can be concluded that the main functional actions of coolants are lubricating and cooling [17]. But modeling even one of the types of functional actions will allow choosing a coolant that will reduce the influence of negative factors occurring during the workpiece processing. What is important is only which of the functional actions is the most significant one under the given processing conditions. One of the most important functional actions of the coolant is the lubricating action. This is justified by the fact that a decrease in the force and the coefficient of friction during cutting provides a decrease in the intensity of the cutting tool wear, an increase in the quality of the processed surface of the workpiece and a decrease in the temperature in the processing zone. Therefore, improving the lubricating effect of a coolant is an important task. The analysis of the scientific literature published recently has shown that reducing the influence of friction on the cutting process is still an urgent task. Friction reduction is achieved in several ways: – addition of particles of any substance that has an antifriction effect to the coolant composition [1, 3, 4, 6, 8, 9, 15–20]; – use of solid lubricants instead of liquid and anti-wear coatings on the cutting tool surfaces [7, 10–12, 21, 22]; – various physical phenomena effecting the coolant, such as ultrasound, electric current and others [11, 13, 14]; – using more effective oils as a coolant base [2, 20]; – increasing the service life of the coolant by its sterilization in various ways, which allows to maintain a low coefficient of friction for longer period [23]; – using ionic liquids as coolants [8, 14, 24]. Despite the large number of ways to reduce friction in the cutting zone, the problem of choosing the most effective coolant for cutting metal workpieces has not been completely solved at present. In addition, the choice of a coolant is also difficult because there is a fairly large constantly increasing range of coolants on sale. This research work is aimed at developing a methodology for accelerated evaluation of the lubricating properties of a coolant. The results obtained will facilitate the selection of an effective brand of a coolant according to its lubricating action. Therefore, the presented results will be useful for those cutting conditions, under which large frictional forces arise, for example, during rough cutting. This is due to the fact that during roughing, a large cutting depth and feed rate are set. Thus, the purpose of this work is to develop a methodology for an accelerated assessment of the lubricating properties of cutting fluids used in metal cutting. To achieve this purpose, it is necessary to solve the following tasks: 1) to evaluate experimentally the lubricating effect of the coolant on the friction machine;
RkJQdWJsaXNoZXIy MTk0ODM1