OBRABOTKAMETALLOV Vol. 23 No. 3 2021 MATERIAL SCIENCE EQUIPMENT. INSTRUMENTS 4 2 Features of ultrasound application in plasma-mechanical processing of parts made of hard-to-process materials Vagif Abbasov a, Rasim Bashirov b, * Department of Machine Building, Azerbaijan Technical University, 25 H. Cavid avenue, Baku, AZ 1073, Azerbaijan a https://orcid.org/0000-0002-4633-6728, abbasov49@aztu.edu.az, b https://orcid.org/0000-0001-6907-2502, rasim_agma@aztu.edu.az Obrabotka metallov - Metal Working and Material Science Journal homepage: http://journals.nstu.ru/obrabotka_metallov Obrabotka metallov (tekhnologiya, oborudovanie, instrumenty) = Metal Working and Material Science. 2022 vol. 24 no. 3 pp. 53–65 ISSN: 1994-6309 (print) / 2541-819X (online) DOI: 10.17212/1994-6309-2022-24.3-53-65 ART I CLE I NFO Article history: Received: 06 April 2022 Revised: 19 April 2022 Accepted: 27 June 2022 Available online: 15 September 2022 Keywords: Hard-to-process materials Plasmatron holder Machinability coeffi cient Ultrasonic Cutter Ultrasonic turning device Plasma-mechanical processing Plasma-ultrasonic treatment Cutter wear Vibrational deformation of the chip. ABSTRACT Introduction. Structural materials, including materials made of heat-resistant and hard-to-work steels, are widely used in various branches of mechanical engineering. To increase the effi ciency of manufacturing parts of thermal equipment from heat-resistant and hard-to-work steels, the technological method of cutting with preliminary plasma heating of the workpiece is used. There is also a technological method of cutting metals, including hard-to-process materials by ultrasonic turning. Proceeding from this, in order to increase the effi ciency of plasma machining of hard-to-process materials, it is necessary to investigate the technological possibilities of using ultrasonic turning of hard-to-process materials during plasma machining. The purpose of the work: to investigate the wear of cutting tools when using ultrasound in the conditions of plasma-mechanical processing of parts made of hard-to-process materials. The paper investigates the features of the plasma-mechanical processing under ultrasonic cutting conditions and determines the wear values of carbide cutters VK8, T5K10 and T15K6 when processing steels of grades 20Cr13Ni18 and 20Cr25Ni20Si2(cast). And also the wear of these cutters was determined under the conditions of conventional turning of the same materials to compare the results of wear of the cutters in different processing conditions. The research method is to determine the linear wear of carbide cutters along the back surface with conventional, plasma-mechanical and plasma-mechanical cutting assisted with ultrasonic cutting using an instrumental microscope and visual estimation with a 10x magnifying glass. Results and discussion. The paper presents the results of experimental studies to determine the wear of cutting tools when processing heat-resistant steels of the 20Cr13Ni18 and 20Cr25Ni20Si2(cast) grades with carbide cutters of the VK8, T5K10 and T15K6 grades. Studies were carried out to determine the wear of carbide cutters as with conventional mechanical cutting, plasma-mechanical cutting, as well as plasma-mechanical cutting using ultrasound. The experiments were carried out when turning these materials on a modernized lathe mod.1A64. A rectifi er with a controlled choke and a plasma torch mod.APR-403 are connected to the lathe; a plasma holder is placed on the lathe carriage. A semiconductor rectifi er serves as a power source with a compressed electric arc of current. The arcing takes place between the cathode (plasma torch) and the anode (blank) at the point of the plasma-forming gas; compressed air passes through the nozzle channel of the plasma torch. During the experiments, the position of the plasma torch was adjusted relative to the part rotation axis. When conducting experiments on studying the wear of cutters under conditions of ultrasonic plasma-mechanical cutting, ultrasound was applied to the cutting edge using a device developed by the authors. When processing heat-resistant steels under the usual turning condition, processing modes were adopted: cutting speed V = 10 m/min, cutting depth t = 3...4 mm, longitudinal feed Sl = 0.31 mm/rev. It is found that when processing steel grade 20Cr13Ni18 by conventional cutting, the back surface of the carbide cutter made of T5K10 wears out to 1 mm in size within 10 minutes, and for the cutter made of VK8 – within 15 minutes. During plasma machining, the cutting speed and the feed rate were increased 2 times; the results of the wear of the cutters show that at the same time T5K10 wears out to 1 mm within 20 minutes, VK8 – within 25 minutes. Plasma-mechanical processing using ultrasound show that the carbide cutter T5K10 wears out by 0.50 mm in less than 50 minutes of cutting, and VK8 wears out by 0.35 mm. The same results are obtained when processing heat-resistant steel 20Cr25Ni20Si2(cast). Thus, the study of wear of carbide cutters in the processing of heat-resistant steels shows that the use of ultrasonic cutting in plasma-mechanical processing of steels can signifi cantly reduce the amount of tool wear. The presented results confi rm the prospects of using ultrasonic plasma-mechanical cutting of heat-resistant steels with blade tools. For citation: Abbasov V.A., Bashirov R.J. Features of ultrasound application in plasma-mechanical processing of parts made of hard-toprocess materials. Obrabotka metallov (tekhnologiya, oborudovanie, instrumenty) = Metal Working and Material Science, 2022, vol. 24, no. 3, pp. 53–65. DOI: 10.17212/1994-6309-2022-24.3-53-65. (In Russian). ______ * Corresponding author Bashirov Rasim J., D.Sc. (Engineering), Professor Department of Machine Building, Azerbaijan Technical University, AZ 1073, 25 H. Cavid avenue, Baku, Azerbaijan Tel: +994 (50) 212 22 73,e-mail: rasim_agma@aztu.edu.az
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