rus
TS_pub
technospheramag
technospheramag
ТЕХНОСФЕРА_РИЦ
Issue #1/2023
X. A. Egorova, K. A. Rozanov, A. I. Kiian, D. A. Sinev
Features of Additive Laser Processing for the Surface Layer Hardness Increase on Titanium Samples
Features of Additive Laser Processing for the Surface Layer Hardness Increase on Titanium Samples
DOI: 10.22184/1993-7296.FRos.2023.17.1.16.24
This article presents the research results on the control of the mechanical and functional titanium parameters by an additive surface laser micro-treatment with an additional graphite layer under the influence of near-IR laser radiation. The results of experimental studies on selection of the optimal laser radiation parameters for increasing the hardness and wear resistance of a model titanium sample are provided. The results demonstrate significantly increased hardness of the treated area (up to 9.3 times) and a decreased abrasive wear resistance rate by about 2 times compared to the original sample.
This article presents the research results on the control of the mechanical and functional titanium parameters by an additive surface laser micro-treatment with an additional graphite layer under the influence of near-IR laser radiation. The results of experimental studies on selection of the optimal laser radiation parameters for increasing the hardness and wear resistance of a model titanium sample are provided. The results demonstrate significantly increased hardness of the treated area (up to 9.3 times) and a decreased abrasive wear resistance rate by about 2 times compared to the original sample.
Теги: hardness increase laser micro-structuring of titanium laser thermochemistry wear resistance enhancement лазерная термохимия лазерное микроструктурирование титана повышение твердости увеличение износостойкости
Features of Additive Laser Processing for the Surface Layer Hardness Increase on Titanium Samples
X. A. Egorova1, K. A. Rozanov1, A. I. Kiian2, D. A. Sinev1
ITMO University, Saint Petersburg, Russia
INSCIENCE, Saint Petersburg, Russia
This article presents the research results on the control of the mechanical and functional titanium parameters by an additive surface laser micro-treatment with an additional graphite layer under the influence of near-IR laser radiation. The results of experimental studies on selection of the optimal laser radiation parameters for increasing the hardness and wear resistance of a model titanium sample are provided. The results demonstrate significantly increased hardness of the treated area (up to 9.3 times) and a decreased abrasive wear resistance rate by about 2 times compared to the original sample.
Keywords: hardness increase, wear resistance enhancement, laser thermochemistry, laser micro-structuring of titanium
Received on: 24.10.2022
Accepted on: 19.12.2022
INTRODUCTION
Continuous improvement in the performance and efficiency of existing methods, as well as upgrading and extending the service life of the devices used, represent a significant challenge for the innovation-based economy. A good example can be the search for new methods to increase the wear resistance of assemblies and parts subject to the frictional wear, including the cutting edges of guillotine-type knives, scissors, cutters, etc. Since the wear resistance is directly related to the hardness parameter of the part, the scientific challenge is in the need for an experimental search for methods and approaches to increasing the hardness of the surface layers of functional alloys.
It is well-known that the traditional quenching methods, i. e. increase of the material hardness during the isothermal heating, require a subsequent annealing procedure to reduce residual stresses on the metal surface [1, 2]. Such shortcomings can be partly compensated by application of the surface local laser quenching and thermal strengthening methods [3–5]. On the other part, the hardening methods based on the laser and non-laser deposition of highly rigid materials (carbide, diamond-like, and other coatings) make it possible to achieve the desired results. However, they are limited by the low graphite solubility in the metal and require more production steps [6, 7]. It is possible to compensate for shortcomings of the mentioned technologies using the additive laser methods that make it possible to evolve a surface structure with the desired geometric and physicochemical properties by combining the laser processing parameters and schemes with auxiliary materials [8–10]. This paper presents the experimental study results of the possibilities provided by the laser formation of surface layers with the increased hardness and wear resistance values due to the metal part processing under a layer of graphite powder in the compressed conditions.
Research materials and equipment
Grade2 commercial titanium being widely used as a functional metal due to its high strength, hypoallergenicity and biological compatibility, as well as high exploration state of the thermal and thermochemical laser exposure mechanisms in the air, was selected as a model material for the study [11, 12]. In the present research the plates with a thickness of about 1 mm were used. Structuring of thinner parts according to the proposed method is also possible; however, in order to preserve the geometry of a part with small thickness, it is necessary to use additional design clamping devices to avoid the occurrence of thermomechanical deformations.
Prior to the laser processing, the parts were treated by the abrasive paper with various grain sizes (P600–P2 500). The final polishing was performed with the felt discs using the Luxor corundum paste with various sizes of structural elements (from 0.5 µm to 0.1 µm) and a Dremel 300 mini-drill. All samples were cleaned in an ultrasonic bath with distilled water for 20 minutes to remove the polishing paste particles.
The samples were structured using a commercially available laser machining system based on a pulsed ytterbium optical fiber laser (Minimarker‑2 produced by Laser Center LLC), with a power of up to 20 W and an emission wavelength of 1 070 nm. Laser radiation was focused on the titanium sample surface into a spot with the diameter of about 50 μm; irradiation was carried out in the air.
The morphology of the obtained structures was studied using a Carl Zeiss Axio Imager A1.m optical microscope. The hardness test was performed using a PMT‑3 hardness gauge by the Vickers test method under the static load. In this method, the indenter was a tetrahedral pyramid with a square base having an angle between the sides at the top equal to 136°.
The mechanical stability was tested using a friction wear test bench and a roller counterbody. To bring the test conditions closer to the operational ones, the counterbody material class was selected in compliance with the future operating interaction materials (aluminum). Additional abrasive wear test was carried out using a counterbody made of polymethyl acrylate with the diamond powder. The particle size of the diamond powder was 0.3 μm.
At the preliminary stage of preparing a polished sample, the laser-induced oxide layers were formed. The main processing stage was laser processing of titanium samples under a layer of graphite powder being in the compressed conditions under an auxiliary glass slide. The visual framework of the experiment is shown in Fig. 1a. To prevent the graphite layer expansion, a glass slide was used with the thickness of about 1.12 mm (State standart 9284–75). The hardness increasing mechanism for the surface layer was based on the laser radiation conversion due to its high absorption by graphite and generation of a compressed microplasma [13]. It led to restructuring of the titanium surface layer. After the treatment, the glass slide and unused graphite powder were removed from the surface. To completely remove the powdered graphite particles, the sample was placed in an ultrasonic bath for 20 minutes, then the sample was air-dried.
The hardness of structures placed on the oxide layer preliminarily formed at a scanning speed of V=100 mm/s reached 500–700 HV (Fig. 1b, c). The recording parameters corresponded to generation of a two-layer structure consisting of an inner TiO2 film with the thickness of about 20 ± 3 nm and an outer Ti3O5 film with the thickness of about 40 ± 5 nm [11]. Moreover, the preliminary stage of sample preparation makes it possible to efficiently adapt this method to specific tasks by varying the final hardness values in the presence of one set of materials, simply by selecting the thickness of the initial oxide layer.
IMPACT ASSESSMENT OF LASER PROCESSING PARAMETERS ON THE HARDNESS OF THE TITANIUM SAMPLE SURFACE LAYER
The revealed operating modes of a titanium sample structuring under a layer of graphite powder and an array of measured hardness values of the treated areas are presented in the form of comparative diagrams (Fig. 2). As a result of processing, an increase in the Vickers hardness value up to 9.3 times (2 330 HV) compared to the value typical for the original surface layer of the titanium plate (244 HV) was shown. One or two exposures are sufficient for the efficient formation of structures with high hardness, since an increase in the number of exposures has not led to an observed improvement in the sample specifications.
IMPACT ASSESSMENT OF LASER PROCESSING PARAMETERS ON THE WEAR RESISTANCE OF THE TITANIUM SAMPLE SURFACE LAYER
Aluminum was selected as the counterbody material for testing, since it is one of the main materials used in industry, in particular, in the manufacture of semi-finished products (for example, sheets, plates, sections, rods, stampings) that are subsequently subject to cutting and processing. When studying the structures using an optical microscope, it was found that the grooves formed by the laser radiation were filled with the counterbody wear products, without abrasion of the entire sample structure. This result indicates a high mechanical stability and efficient operation of the structured elements during the frictional interaction with the parts made of aluminum alloy.
Additional abrasive wear tests were performed using a counterbody consisting of polymethyl acrylate with the diamond powder. The contact profilometry results (Fig. 3) show that there is a difference in the height of the maximum structural peaks equal to 5 μm between the area of the original structure and the area to which the center of the roller counterbody side face arrives. This result indicates a slight erosion of structure during interaction with the counterbody. Moreover, the structure contains residual materials of the counterbody; probably, with a longer interaction time, filling of the structure grooves with the counterbody material would occur.
The measured wear rate of the titanium sample initial surface layer is about 4.8 · 10–4 m/h, and the wear rate of the treated surface is about 3 .0· 10–4 m/h. Thus, it is shown that the wear parameter can be reduced by at least 1.6 times due to the proposed processing method, and the treated structure belongs to the 4th wear resistance class [14] in the case of abrasive impact.
CONCLUSION
As a result of experimental studies, the effect of laser radiation modes on the morphological and functional properties of the VT1-0 titanium alloy surface layer by modification under the layers of auxiliary substances was examined using a commercially available laser machining system based on a pulsed optical fiber laser.
An efficiency enhancement method of additive processing with the use of an auxiliary cover glass holding the graphite powder in the laser impact zone was tested. It was possible to obtain the increased hardness of the titanium sample surface layer by about 10 times (2 330 HV) compared with the hardness value of the original titanium (244 HV). During the additive processing procedure using the laser radiation under a layer of graphite with different modes, it was found that the most promising processing modes suitable for the functional applications are obtained at 1–2 consecutive exposures with a power of 7–8 W (for pulses with a duration of 100 ns) and 15–17 W (for pulses with a duration of 200 ns), with the pulse repetition rates of 60–80 kHz.
Additionally, we have determined the possible reduction in the abrasive wear rate of the titanium sample surface layer by at least 2 times compared with the initial one due to the laser structuring under a graphite layer.
The results obtained in this project have prospects for wide application in the metalworking manufacturing industry in the form of an additive laser processing technology for flat cutting tools to increase the service life of machining facilities. Additionally, the results can be easily scaled up for similar machining of bulky tools (milling cutters, turning cutters, drills) by changing the laser action sweep from flat-field to the cylindrical one.
Acknowledgements
The authors express gratitude to the group of professor Yu. R. Kolobov (Institute of Problems of Chemical Physics, Russian Academy of Sciences), Laser Center LLC for assistance in the study of research prototypes, including the development and provision of equipment, as well as for valuable discussions.
The works were performed with financial support from the Ministry of Science and Higher Education of the Russian Federation according to the Government Decree No. 218 dated April 09, 2010 (agreement No. 075-11-2021-045 dated June 24, 2021, project name: “Establishment of high-tech manufacturing of the equipment and technologies for laser functionalization of the medical device surface”), and financial support for academic qualification of the bachelors, masters and post-graduate students as a part of research works on the basis of the School of Physics and Engineering, ITMO University (R&D competition for the masters and post-graduate students).
ABOUT AUTHORS
Egorova Xenia Andreevna, PhD student, research engineer, Institute of Laser Technologies, ITMO University, St. Petersburg, Russia.
ORCID 0000-0002-4228-0392
Rozanov Konstantin Alexandrovich, student, Institute of Laser Technologies, ITMO University, St. Petersburg, Russia.
Kiian Anton Igorevich, engineer, INSCIENCE, St. Petersburg, Russia.
Sinev Dmitry Andreevich, Candidate of Technical Sciences, assistant, Institute of Laser Technologies, ITMO University, St. Petersburg, Russia, sinev@itmo.ru
ORCID 0000-0002-6274-1491
CONTRIBUTION OF THE AUTHORS
Egorova X. A. – organization of work, conducting a research process, analyzing the results, discussing, text editing, suggestions and comments; Rozanov K. A. – conducting a research process, discussing, writing the initial draft; Kiian A. I. – idea, experiment design, discussions, suggestions and comments; Sinev D. A. – idea, experiment design, organization of work, discussions, text editing, suggestions and comments.
CONFLICT OF INTEREST
The authors declare that they have no conflict of interest and they supplemented the manuscript in part of their work.
REFERENCES
Knunyants I. L., Zefirov N. S. Chemical Encyclopedia: in 5 volumes / Editorial Board.: Zefirov N. S. (chief editor) and others – M.: Great Russian Encyclopedia. 1995; 4:641.(In Russ.).
Кнунянц И. Л., Зефиров Н. С. Химическая энциклопедия: в 5 т. /Редкол.: Зефиров Н. С. (гл. ред.) и др. – М.: Большая Российская энциклопедия. 1995; 4:641.
Kazachenok M. S., Panin A. V., Ivanov Yu. F., Pochivalov Yu. I., Valiev R. Z. The effect of thermal annealing on the mechanical behavior of technical titanium VT1-0, having a submicrocrystalline structure in the surface layer or in the volume of the material. Physical mesomechanics. 2005; 8(4): 37–47. DOI:10.24411/1683‑805X‑2005‑00024. (In Russ.).
Казаченок М. С., Панин А. В., Иванов Ю. Ф., Почивалов Ю. И., Валиев Р. З. Влияние термического отжига на механическое поведение технического титана ВТ1-0, имеющего субмикрокристаллическую структуру в поверхностном слое или в объеме материала. Физическая мезомеханика. 2005; 8(4): 37–47.
Grum J. Comparison of different techniques of laser surface hardening / Grum J // Journal of Achievements in Materials and Manufacturing Engineering. 2007; Vol. 24:17–25.
Ali Khorram, Akbar Davoodi Jamaloei. Nd : YAG laser surface hardening of AISI 431 stainless steel; mechanical and metallurgical investigation. Optics and Laser Technology. 2019; 119: 105617. DOI: 10.1016/J.OPTLASTEC.2019.105617
Mahmoud Moradi, Hossein Arabi. Enhancement of surface hardness and metallurgical properties of AISI 410 by laser hardening process; diode and Nd : YAG lasers. Optik. 2019; 188:277–286. DOI: 10.1016/j.ijleo.2019.05.057
N. Zarrinfar, P. H. Shipway, A. R. Kennedy, A. Saidi. Carbide stoichiometry in TiC and Cu-TiCx produced by self-propagating high-temperature synthesis. Scripta Materialla. 2002; 46:121–126. DOI:10.1016/S1359‑6462(01)01205‑2
Kiparisov S. S., Levinsky Yu.V., Petrov A. P. Titanium carbide: preparation, properties, application. – M.: Metallurgy, 1987, 216 p. (In Russ.).
Кипарисов С. С., Левинский Ю. В., Петров А. П. Карбид титана: получение, свойства, применение. – М.: Металлургия, 1987, 216 с.
Maharjan N, Zhou W, Wu N. Direct laser hardening of AISI 1020 steel under controlled gas atmosphere. Surface and Coatings Technology. 2020;15:125399. DOI: 10.1016/j.surfcoat.2020.125399.
Nair A. M., Muvvala G., Nath A. K. A study on in-situ synthesis of TiCN metal matrix composite coating on Ti‑6Al‑4V by laser surface alloying process. Journal of Alloys and Compounds. 2019; 810:151901. DOI: 10.1016/j.jallcom.2019.151901
Shi J, Wang Y. Development of metal matrix composites by laser-assisted additive manufacturing technologies: a review. Journal of Materials Science. 2020; 55(23):9883–917. DOI: 10.1007/s10853‑020‑04730‑3.
Veiko V. P., Andreeva Y., Van Cuong L., Lutoshina D., Polyakov D., Sinev D., Mikhailovskii V., Kolobov Y. R., Odintsova G. Laser paintbrush as a tool for modern art. Optica. 2021 May 20;8(5):577–85. DOI: 10.1364/OPTICA.420074.
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X. A. Egorova1, K. A. Rozanov1, A. I. Kiian2, D. A. Sinev1
ITMO University, Saint Petersburg, Russia
INSCIENCE, Saint Petersburg, Russia
This article presents the research results on the control of the mechanical and functional titanium parameters by an additive surface laser micro-treatment with an additional graphite layer under the influence of near-IR laser radiation. The results of experimental studies on selection of the optimal laser radiation parameters for increasing the hardness and wear resistance of a model titanium sample are provided. The results demonstrate significantly increased hardness of the treated area (up to 9.3 times) and a decreased abrasive wear resistance rate by about 2 times compared to the original sample.
Keywords: hardness increase, wear resistance enhancement, laser thermochemistry, laser micro-structuring of titanium
Received on: 24.10.2022
Accepted on: 19.12.2022
INTRODUCTION
Continuous improvement in the performance and efficiency of existing methods, as well as upgrading and extending the service life of the devices used, represent a significant challenge for the innovation-based economy. A good example can be the search for new methods to increase the wear resistance of assemblies and parts subject to the frictional wear, including the cutting edges of guillotine-type knives, scissors, cutters, etc. Since the wear resistance is directly related to the hardness parameter of the part, the scientific challenge is in the need for an experimental search for methods and approaches to increasing the hardness of the surface layers of functional alloys.
It is well-known that the traditional quenching methods, i. e. increase of the material hardness during the isothermal heating, require a subsequent annealing procedure to reduce residual stresses on the metal surface [1, 2]. Such shortcomings can be partly compensated by application of the surface local laser quenching and thermal strengthening methods [3–5]. On the other part, the hardening methods based on the laser and non-laser deposition of highly rigid materials (carbide, diamond-like, and other coatings) make it possible to achieve the desired results. However, they are limited by the low graphite solubility in the metal and require more production steps [6, 7]. It is possible to compensate for shortcomings of the mentioned technologies using the additive laser methods that make it possible to evolve a surface structure with the desired geometric and physicochemical properties by combining the laser processing parameters and schemes with auxiliary materials [8–10]. This paper presents the experimental study results of the possibilities provided by the laser formation of surface layers with the increased hardness and wear resistance values due to the metal part processing under a layer of graphite powder in the compressed conditions.
Research materials and equipment
Grade2 commercial titanium being widely used as a functional metal due to its high strength, hypoallergenicity and biological compatibility, as well as high exploration state of the thermal and thermochemical laser exposure mechanisms in the air, was selected as a model material for the study [11, 12]. In the present research the plates with a thickness of about 1 mm were used. Structuring of thinner parts according to the proposed method is also possible; however, in order to preserve the geometry of a part with small thickness, it is necessary to use additional design clamping devices to avoid the occurrence of thermomechanical deformations.
Prior to the laser processing, the parts were treated by the abrasive paper with various grain sizes (P600–P2 500). The final polishing was performed with the felt discs using the Luxor corundum paste with various sizes of structural elements (from 0.5 µm to 0.1 µm) and a Dremel 300 mini-drill. All samples were cleaned in an ultrasonic bath with distilled water for 20 minutes to remove the polishing paste particles.
The samples were structured using a commercially available laser machining system based on a pulsed ytterbium optical fiber laser (Minimarker‑2 produced by Laser Center LLC), with a power of up to 20 W and an emission wavelength of 1 070 nm. Laser radiation was focused on the titanium sample surface into a spot with the diameter of about 50 μm; irradiation was carried out in the air.
The morphology of the obtained structures was studied using a Carl Zeiss Axio Imager A1.m optical microscope. The hardness test was performed using a PMT‑3 hardness gauge by the Vickers test method under the static load. In this method, the indenter was a tetrahedral pyramid with a square base having an angle between the sides at the top equal to 136°.
The mechanical stability was tested using a friction wear test bench and a roller counterbody. To bring the test conditions closer to the operational ones, the counterbody material class was selected in compliance with the future operating interaction materials (aluminum). Additional abrasive wear test was carried out using a counterbody made of polymethyl acrylate with the diamond powder. The particle size of the diamond powder was 0.3 μm.
At the preliminary stage of preparing a polished sample, the laser-induced oxide layers were formed. The main processing stage was laser processing of titanium samples under a layer of graphite powder being in the compressed conditions under an auxiliary glass slide. The visual framework of the experiment is shown in Fig. 1a. To prevent the graphite layer expansion, a glass slide was used with the thickness of about 1.12 mm (State standart 9284–75). The hardness increasing mechanism for the surface layer was based on the laser radiation conversion due to its high absorption by graphite and generation of a compressed microplasma [13]. It led to restructuring of the titanium surface layer. After the treatment, the glass slide and unused graphite powder were removed from the surface. To completely remove the powdered graphite particles, the sample was placed in an ultrasonic bath for 20 minutes, then the sample was air-dried.
The hardness of structures placed on the oxide layer preliminarily formed at a scanning speed of V=100 mm/s reached 500–700 HV (Fig. 1b, c). The recording parameters corresponded to generation of a two-layer structure consisting of an inner TiO2 film with the thickness of about 20 ± 3 nm and an outer Ti3O5 film with the thickness of about 40 ± 5 nm [11]. Moreover, the preliminary stage of sample preparation makes it possible to efficiently adapt this method to specific tasks by varying the final hardness values in the presence of one set of materials, simply by selecting the thickness of the initial oxide layer.
IMPACT ASSESSMENT OF LASER PROCESSING PARAMETERS ON THE HARDNESS OF THE TITANIUM SAMPLE SURFACE LAYER
The revealed operating modes of a titanium sample structuring under a layer of graphite powder and an array of measured hardness values of the treated areas are presented in the form of comparative diagrams (Fig. 2). As a result of processing, an increase in the Vickers hardness value up to 9.3 times (2 330 HV) compared to the value typical for the original surface layer of the titanium plate (244 HV) was shown. One or two exposures are sufficient for the efficient formation of structures with high hardness, since an increase in the number of exposures has not led to an observed improvement in the sample specifications.
IMPACT ASSESSMENT OF LASER PROCESSING PARAMETERS ON THE WEAR RESISTANCE OF THE TITANIUM SAMPLE SURFACE LAYER
Aluminum was selected as the counterbody material for testing, since it is one of the main materials used in industry, in particular, in the manufacture of semi-finished products (for example, sheets, plates, sections, rods, stampings) that are subsequently subject to cutting and processing. When studying the structures using an optical microscope, it was found that the grooves formed by the laser radiation were filled with the counterbody wear products, without abrasion of the entire sample structure. This result indicates a high mechanical stability and efficient operation of the structured elements during the frictional interaction with the parts made of aluminum alloy.
Additional abrasive wear tests were performed using a counterbody consisting of polymethyl acrylate with the diamond powder. The contact profilometry results (Fig. 3) show that there is a difference in the height of the maximum structural peaks equal to 5 μm between the area of the original structure and the area to which the center of the roller counterbody side face arrives. This result indicates a slight erosion of structure during interaction with the counterbody. Moreover, the structure contains residual materials of the counterbody; probably, with a longer interaction time, filling of the structure grooves with the counterbody material would occur.
The measured wear rate of the titanium sample initial surface layer is about 4.8 · 10–4 m/h, and the wear rate of the treated surface is about 3 .0· 10–4 m/h. Thus, it is shown that the wear parameter can be reduced by at least 1.6 times due to the proposed processing method, and the treated structure belongs to the 4th wear resistance class [14] in the case of abrasive impact.
CONCLUSION
As a result of experimental studies, the effect of laser radiation modes on the morphological and functional properties of the VT1-0 titanium alloy surface layer by modification under the layers of auxiliary substances was examined using a commercially available laser machining system based on a pulsed optical fiber laser.
An efficiency enhancement method of additive processing with the use of an auxiliary cover glass holding the graphite powder in the laser impact zone was tested. It was possible to obtain the increased hardness of the titanium sample surface layer by about 10 times (2 330 HV) compared with the hardness value of the original titanium (244 HV). During the additive processing procedure using the laser radiation under a layer of graphite with different modes, it was found that the most promising processing modes suitable for the functional applications are obtained at 1–2 consecutive exposures with a power of 7–8 W (for pulses with a duration of 100 ns) and 15–17 W (for pulses with a duration of 200 ns), with the pulse repetition rates of 60–80 kHz.
Additionally, we have determined the possible reduction in the abrasive wear rate of the titanium sample surface layer by at least 2 times compared with the initial one due to the laser structuring under a graphite layer.
The results obtained in this project have prospects for wide application in the metalworking manufacturing industry in the form of an additive laser processing technology for flat cutting tools to increase the service life of machining facilities. Additionally, the results can be easily scaled up for similar machining of bulky tools (milling cutters, turning cutters, drills) by changing the laser action sweep from flat-field to the cylindrical one.
Acknowledgements
The authors express gratitude to the group of professor Yu. R. Kolobov (Institute of Problems of Chemical Physics, Russian Academy of Sciences), Laser Center LLC for assistance in the study of research prototypes, including the development and provision of equipment, as well as for valuable discussions.
The works were performed with financial support from the Ministry of Science and Higher Education of the Russian Federation according to the Government Decree No. 218 dated April 09, 2010 (agreement No. 075-11-2021-045 dated June 24, 2021, project name: “Establishment of high-tech manufacturing of the equipment and technologies for laser functionalization of the medical device surface”), and financial support for academic qualification of the bachelors, masters and post-graduate students as a part of research works on the basis of the School of Physics and Engineering, ITMO University (R&D competition for the masters and post-graduate students).
ABOUT AUTHORS
Egorova Xenia Andreevna, PhD student, research engineer, Institute of Laser Technologies, ITMO University, St. Petersburg, Russia.
ORCID 0000-0002-4228-0392
Rozanov Konstantin Alexandrovich, student, Institute of Laser Technologies, ITMO University, St. Petersburg, Russia.
Kiian Anton Igorevich, engineer, INSCIENCE, St. Petersburg, Russia.
Sinev Dmitry Andreevich, Candidate of Technical Sciences, assistant, Institute of Laser Technologies, ITMO University, St. Petersburg, Russia, sinev@itmo.ru
ORCID 0000-0002-6274-1491
CONTRIBUTION OF THE AUTHORS
Egorova X. A. – organization of work, conducting a research process, analyzing the results, discussing, text editing, suggestions and comments; Rozanov K. A. – conducting a research process, discussing, writing the initial draft; Kiian A. I. – idea, experiment design, discussions, suggestions and comments; Sinev D. A. – idea, experiment design, organization of work, discussions, text editing, suggestions and comments.
CONFLICT OF INTEREST
The authors declare that they have no conflict of interest and they supplemented the manuscript in part of their work.
REFERENCES
Knunyants I. L., Zefirov N. S. Chemical Encyclopedia: in 5 volumes / Editorial Board.: Zefirov N. S. (chief editor) and others – M.: Great Russian Encyclopedia. 1995; 4:641.(In Russ.).
Кнунянц И. Л., Зефиров Н. С. Химическая энциклопедия: в 5 т. /Редкол.: Зефиров Н. С. (гл. ред.) и др. – М.: Большая Российская энциклопедия. 1995; 4:641.
Kazachenok M. S., Panin A. V., Ivanov Yu. F., Pochivalov Yu. I., Valiev R. Z. The effect of thermal annealing on the mechanical behavior of technical titanium VT1-0, having a submicrocrystalline structure in the surface layer or in the volume of the material. Physical mesomechanics. 2005; 8(4): 37–47. DOI:10.24411/1683‑805X‑2005‑00024. (In Russ.).
Казаченок М. С., Панин А. В., Иванов Ю. Ф., Почивалов Ю. И., Валиев Р. З. Влияние термического отжига на механическое поведение технического титана ВТ1-0, имеющего субмикрокристаллическую структуру в поверхностном слое или в объеме материала. Физическая мезомеханика. 2005; 8(4): 37–47.
Grum J. Comparison of different techniques of laser surface hardening / Grum J // Journal of Achievements in Materials and Manufacturing Engineering. 2007; Vol. 24:17–25.
Ali Khorram, Akbar Davoodi Jamaloei. Nd : YAG laser surface hardening of AISI 431 stainless steel; mechanical and metallurgical investigation. Optics and Laser Technology. 2019; 119: 105617. DOI: 10.1016/J.OPTLASTEC.2019.105617
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