For more than ten years, Igor Sikorsky Kyiv Polytechnic Institute has been cooperating with the University of the Basque Country (Universidad del País Vasco, Spain) and the Kurdyumov Institute of Metallophysics of the National Academy of Sciences of Ukraine to improve the processing of metal products for high-tech industrial applications.

According to the Department of Laser Engineering and Physical and Technical Technologies (LTFT) of the E.O. Paton Educational and Research Institute of Materials Science and Welding. Paton, where they study the effect of laser and physical-technical or combined/hybrid processing of materials with highly concentrated energy sources on surface microrelief and physical and mechanical (operational) properties, the innovative method of selective laser powder bed fusion (LPBF) allows for thin-walled/hollow parts and provides full automation of their manufacture, while reducing the weight and time of the product. The method is successfully used when working with difficult-to-machine materials such as titanium and nickel alloys. However, there are some drawbacks. On the one hand, LPBF technology is effective in the manufacture of monolithic 3D objects of complex geometric shapes that are difficult or impossible to produce using traditional methods. On the other hand, poor integrity, varying surface roughness, and structural defects in products limit its widespread use.

"Indeed, optimization and improvement of post-processing methods, including combined/hybrid technologies of surface modification with highly concentrated energy sources, are very relevant today, as they can significantly improve the surface quality and properties of the printed material," says Oleksii Kahliak, acting head of the LTFT department, and continues: "The first results were obtained during the internship of our researcher Dmytro Lesyk at the Otto von Guericke University of Magdeburg (Germany) in 2018-2019 under the DAAD academic exchange program. Back then, advanced machining methods were used to improve surface parameters by providing nanostructuring and residual compressive stresses in the near-surface layer."

So, is Dmytro Lesyk the driving force behind this topic? Let's get acquainted. The scientist willingly tells us about himself: "I entered the Institute of Mechanical Engineering in 2005 after graduating from the Polonsky Gymnasium (now the Polonsky Lyceum No. 1). In 2011, he graduated from Igor Sikorsky Kyiv Polytechnic Institute with a degree in Materials Processing by Special Technologies and worked as a design engineer at UkrliftService. In 2011-2015, he studied at the postgraduate program of Igor Sikorsky Kyiv Polytechnic Institute, having completed a 10-month internship at the University of the Basque Country (Spain) with the support of the Erasmus Mundus program. In 2016, under the scientific supervision of Professor Vitalii Dzhemelinskyi, he defended his PhD thesis in the specialty "Physical and technical processing processes". His dissertation was on a new method of combined laser-ultrasonic hardening and finishing of large steel products. Since then, his research interests have included post-processing of products manufactured using additive technologies.

By the way, after completing his postgraduate studies, the scientist remained at the department and in 2017 initiated a research project on post-treatment of products manufactured using the LPBF method together with the Aeronautics Production Center of the University of the Basque Country, Motor Sich JSC, and the Kurdyumov Institute of Metallophysics of the National Academy of Sciences of Ukraine. The cooperation continues to this day, enriching the scientific schools of Ukraine and Spain.

It is worth noting that during this time, the young scientist has published more than 80 scientific and methodological works, including 28 articles in international Scopus journals, 13 articles in scientific professional journals, 5 articles in conference proceedings, 16 chapters of a monograph in international journals, and 5 textbooks. In addition, he received 14 utility model patents of Ukraine. Today, the scientist's H-index in the Scopus database is 13. The researcher is one of the executors of international scientific projects of the Ministry of Education and Science (M/78-2021, M/18 2022, M/67 2022), state budget topics of the Ministry of Education and Science (2725p, 2102p, 2401p, 2405f), projects of the National Academy of Sciences of Ukraine (0122U002555, 0119U001167) and the National Research Foundation project (2022.01/0038). He is also a member of the program committee of the DSMIE International Conference and the International Association for Technological Development and Innovation. In 2020-2022, Dmytro Lesyk was well deservedly awarded a scholarship from the Cabinet of Ministers of Ukraine for young scientists. He has also won the university competition "Young Teacher-Researcher" five times (annually since 2019).
Currently, Dmytro Lesyk, PhD, Associate Professor, teaches classes in Machine Parts and Design Basics and Process Equipment Control Systems, and in 2021 he taught the Advanced Material Processing Technique course in English for foreign students. He has also taught courses, laboratory and practical classes in the disciplines "Technology of Structural (and Aviation) Materials", "Fundamentals of Professional Activity", "Materials Science and Technology of Materials", "Properties and Technology of Materials Processing" and "Structure, Properties and Processing of Materials". Today, the lecturer is responsible for the scientific work of the department and the scientific group IMZ 14 "Post-processing of products made using additive technologies". He devotes his free time to his wonderful family, especially his newborn daughter.

As you know, scientific research does not stand still. In 2022-2023, the scientist received research grants for individual projects at the West Pomeranian University of Technology (Poland) and the University of Idaho (USA). The work concerned new methods of thermomechanical post-treatment of LPBF-printed aviation and medical products and ensuring their performance properties in the context of reliability and durability. "Thus," the interlocutor emphasizes, "the scientists of Igor Sikorsky Kyiv Polytechnic Institute and the University of Idaho conducted joint research in the field of additive manufacturing for the first time within the FRDP program. The results were presented at the TMS Annual Meeting & Exhibition in San Diego." In addition, D. Lesyk's report "Laser powder bed fusion fabrication and post-processing of customized metal dental products" at the 6th International Conference DSMIE-2023 (Slovakia) was recognized as the best in the section "Production Technologies", and a section of the monograph was published in the international edition of Taylor & Francis Group. The acquired experience of scientific cooperation will continue to promote international cooperation between Kyiv Polytechnic and the University of Idaho / West Pomeranian University of Technology, the LTFT Department is confident.

As you can see, the international achievements are significant. But the researcher also has achievements at the university. Dmytro and his team have repeatedly become finalists of the All-Ukrainian Sikorsky Challenge competition with innovative startup projects: "Post-processing of 3D printed products from INCO alloys" (2022), "Production of medical parts with a laser 3D printer" (2019), "Use of pulsed energy sources for the formation of micro- and nanorelief and strengthening of product surfaces" (2012). The proposed innovative production technologies are important and promising, and the technology for finishing and strengthening small-sized steel medical devices was introduced at Ukrtekhmed in 2014-2015. The developments are being actively implemented in the educational process.

Overall, Dmytro Lesyk is successfully continuing his research work. He reflects: "Currently, the global market for additive manufacturing of metal products is worth $3.5 billion, and it is expected to reach approximately $11.5 billion by 2030. In particular, to improve LPBF printing of metal products for high-tech industrial applications, it is necessary to implement technological solutions to control the process of laser fusion of powder materials both at the stage of laser 3D printing and at the stage of post-processing." Recently, with the support of the ADAGIO Postdoctoral Fellowship Program under the Marie Skłodowska-Curie grant, the scientist received a research grant to carry out an individual research project at the University of the Basque Country. He also submitted a project proposal to the competition of the Ministry of Education and Science. "The implementation of these projects," Dmytro shares, "will not only strengthen scientific cooperation between the University of the Basque Country and Igor Sikorsky Kyiv Polytechnic Institute and present a dissertation for a doctoral degree, but will also contribute to the introduction of new modern technologies for the additive manufacturing/restoration of high-quality metal products at Ukrainian enterprises. Let it be so.

At the end of the conversation, the young scientist summarized: "My current achievements are primarily related to systematic work both in a team and independently. And international cooperation, above all, imposes additional responsibility and contributes to obtaining high-quality scientific results." The researcher does not forget to thank his colleagues for their cooperation, especially his supervisor Vitalii Dzhemelinskyi for his professionalism, inspiration, and support. "Together, we can do more for science, technology, engineering, and education," the researcher is confident.

Nadiia Libert