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Energy saving and surface quality are priorities in manufacturing industry with increased sustainability and high-quality consciousness. This paper presents a cooperative optimization approach to choose optimal cutting parameters for energy saving and quality assurance considering the effects of tool wear and cutting parameter combinations at a certain material removal rate. Cutting energy consumption, energy efficiency and surface roughness are optimization objectives and their functions are developed with cutting parameters and tool wear. The multi-objective optimization model is constructed with constraints and solved by NSGA-III. A turning application case is given and the results illustrate the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

The significance of the study is that the analysis of cutting performance and parameter optimization of the disc cutter can effectively improve the service life of the tool and reduce the cutting energy consumption. The method of the study is as follows: The numerical model based on the discrete element method was developed for rock cutting. The validation experiment was carried out to prove the reliability of the numerical model. The effect of swing arm speed, spindle speed and cutting depth on the wear, cutting specific energy and broken rock volume of the disc cutter was analyzed. The prediction models of cutting wear and cutting specific energy were established based on the response surface method, and the parameters were optimized. The validation experiment was carried out with the obtained optimal parameters as experimental conditions. The experiment verifies the reliability of the disc cutter wear and energy consumption optimization models. The conclusion is as follows: The cutting depth has the greatest effect on the wear of the disc cutter, followed by the spindle speed, while the swing arm speed has the least effect on the wear of the disc cutter. With the increase of the swing arm speed and cutting depth, the wear of the disc cutter increases. The maximum cutting wear can reach 4.75 mm and 5.03 mm. The average cutting wear can reach 2.57 mm and 2.29 mm. With the decrease of the spindle speed, the wear of the disc cutter increases, and the maximum wear and average wear can reach 4.71 mm and 2.30 mm. The increase of swing arm speed and cutting depth can improve cutting efficiency, but excessive swing arm speed and cutting depth will increase the wear and reduce the tool life. The swing arm speed has the greatest influence on the cutting specific energy, followed by the spindle speed, while the cutting depth has the least influence on the cutting specific energy. As the swing arm speed increases, the energy consumption of cutting becomes larger. The increase of the swing arm speed can improve the cutting efficiency, but the excessive swing arm speed will increase the energy consumption. With the increase of spindle speed, the rock cutting efficiency of the disc cutter becomes larger, and the energy consumption first decreases and then increases. Too small spindle speed will aggravate the energy consumption. The maximum cutting specific energy can reach 29.85 MJ/m3. When the swing arm speed v = 5 mm/s, the spindle speed n = 99 r/min and the cutting depth h = 14 mm, the wear and energy consumption of the disc cutter are minimal at the same time, which shows that the cutting performance of the disc cutter is better. The average wear and cutting specific energy of the disc cutter after parameter optimization are 1.64 mm and 17.59 MJ/m3, respectively. The conclusion of the study is that the experiments have verified the reliability of the discrete element disc cutter rock cutting analysis model, which can simulate the disc cutter cutting process more accurately. The optimization model is reliable, and the wear and energy consumption of the disc cutter are minimal at the same time after the optimization analysis, which provides a theoretical reference for improving the service life of the disc cutter and reducing the cutting energy consumption. [Display omitted] [ABSTRACT FROM AUTHOR]

Abstract: Inability of machining steel strongly inhibits the application of diamond machining in manufacturing industry, especially in the fields of ultra-precision and micro machining. In recent years, vibration-assisted machining (VAM) has been proved to be capable of efficiently suppressing the diamond tool wear in cutting steel. Currently, the prevailing speculation claimed by most researchers for such suppression is that the tool–workpiece flash temperature was reduced in VAM, which would slow the chemical reaction between iron on steel and carbon on diamond. However, the correctness of this speculation has not been proved by any experimental or theoretical research. In this paper, in order to understand the true wear suppression mechanism of diamond tools in VAM of steel, a study is conducted by measuring the workpiece temperatures and modeling the cutting energy consumption in both VAM and conventional cutting (CC). Based on the comparison results, it is concluded that the cutting temperature and energy consumption in VAM are not smaller than in CC, and hence the reduced diamond tool wear in VAM should not be caused by the claimed reduced temperature, especially when the material removal rate is very small. Finally, based on the EDS analysis and the comparison of experimental results under different air pressure, two probable reasons are proposed for the significantly reduced diamond tool wear in VAM of steel: (i) increase of gas pressure at the tool–workpiece interface and (ii) generation of an oxide layer on the freshly machined surface. [Copyright &y& Elsevier]