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Increasing the wear resistance of a complex profile cutting tool by applying a diffusion discrete coating
Materials Today: Proceedings xxx (xxxx) xxx
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Increasing the wear resistance of a complex profile cutting tool by applying a diffusion discrete coating Elena Chekalova ⇑, Andrey Zhuravlev Moscow Polytechnic University, Moscow, 107023 Avtozavodskaya St. 16, Russia
a r t i c l e
i n f o
Article history: Received 8 July 2019 Accepted 2 August 2019 Available online xxxx Keywords: Composite profile cutting tool Corona discharge Wear resistance Diffusion discrete coating
a b s t r a c t A method for improving the wear resistance of a complex profile cutting tool by applying a diffusion discrete coating is proposed. The results of studies of a complex profile cutting tool on the wear rate of the cutting tool are presented. Ó 2019 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the International Conference on Modern Trends in Manufacturing Technologies and Equipment 2019.
In modern engineering production, more and more sophisticated automated machine tool equipment is being used. During the cutting process, the tool interacts with the material of the workpiece, which is accompanied by a complex set of physicochemical phenomena, namely, the surface layer is subjected to elastoplastic deformation [1]. Currently, there are various methods of applying coatings with different structures allowing to solve a number of tasks of technological operations of cutting, to increase productivity, accuracy and quality of processing. To increase the productivity of the tool, in the coating include alloying elements: Zr, Mo, Al, etc. in the form of soft layers, which affect the structure and physico-mechanical properties of coatings. Such an ambiguous change is associated with the different effects of chemical elements on the reduction of stresses acting on the instrumental basis [2]. Thus, to increase the wear resistance of the coated cutting tool and reduce premature wear, you can use the effect of uneven coating, i.e. coating by a diffusion discrete method, where the starting material is used as soft interlayers [3]. Such a coating structure can serve as an integral characteristic capable of preventing the propagation of cracks and even its stopping during operation at the interface of the tool material and the coating with a lower elastic modulus, which contributes to stress relaxation. It can be assumed that the unevenness of the coating ⇑ Corresponding author.
will contribute to an increase in tool resistance to deformation changes due to the independence of deformation damage of individual cells. This coating increases rigidity, but at the same time retains its strength, preventing surface spreading of cracks in the coating and reducing the elastic – plastic deformation under the influence of thermomechanical stresses, and, thereby, reduces the spread of cracks in the material [3]. Diffuse discrete coating can be different, since for each material the formation of the coating will have its own individual character (iron oxide for steel, tungsten oxide for a hard alloy), depending on the chemical composition of the material. The aim of the work is to study the wear resistance of a complex profile tool with a diffusion discrete coating. For coating, an experimental setup was developed (see Fig. 1), which consists of a ‘‘UIV-1” device with a unipolar positive crown and an electromechanical unit that performs the function of stepwise moving the nozzle. The device ‘‘UIV-1” is a nozzle, an ionizer that combines the organization of a directional air flow and its activation by positive ions. The CNC system monitors the process of step-by-step movements of the nozzle according to the program available on the CNC machine [3]. As a tool, the cutters of steel P18 and cutters made of carbide alloy BR10XOM with diffusion discrete coating were investigated. In the formation of an oxide coating obtained by a diffusion in a discrete manner, physical and chemical processes take place. The
E-mail address: [email protected] (E. Chekalova). https://doi.org/10.1016/j.matpr.2019.08.053 2214-7853/Ó 2019 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the International Conference on Modern Trends in Manufacturing Technologies and Equipment 2019.
Please cite this article as: E. Chekalova and A. Zhuravlev, Increasing the wear resistance of a complex profile cutting tool by applying a diffusion discrete coating, Materials Today: Proceedings, https://doi.org/10.1016/j.matpr.2019.08.053
2
E. Chekalova, A. Zhuravlev / Materials Today: Proceedings xxx (xxxx) xxx
significant advantage over saturation from the vapor-gas phase, because it has: – a high rate of saturation of the surface layer with molecules and ions of activated compressed air; – the possibility of obtaining processes of diffusion saturation regulated by the potential of the corona electrode (corona discharge current); – possibility of thermal diffusion surface saturation without additional depassivating treatment.
Fig. 1. Installation for applying a diffusion discrete coating.
characteristic microstructure of a diffusion discrete coating on tool materials is presented in Fig. 2. Studies in a scanning electron microscope have shown that the coating is a thin uneven epitaxial film and has a grain size of about 4 mm (see Fig. 2) [4,5]. X-ray microscopic analysis confirmed a significant decrease in the content of elements in a metal or alloy after coating, for example: for a hard alloy, the W content in the coating at a depth of 250 nm is 76.28%, while without coating – 85.7%; content of Co decreased slightly. At the same time, it was found that oxygen is present only in the surface layer of the coating, and its content is approximately 14.72% (see Fig. 3). In the coating on a carbide tool as a result of oxidation, predominantly tungsten oxides are formed: its concentration in the spectrum is significantly reduced (Table 1). Thus, it can be assumed that the decrease in the tungsten content in the surface layer is due to the oxidation process with the formation of tungsten oxides. Research confirms that tungsten oxides are part of the coating: tungsten trioxide WO3 (a); WO3 (b), WO3 (c); tungsten dioxide WO2 (d); and cobalt oxides (II, III) Co3O4 and cobalt oxide (II) CoO. In the course of metalphysical and metallographic studies, a coating thickness was obtained, which is approximately 350– 450 nm, while the hardness is 30% higher than the initial hardness. This increase in hardness is associated with the content of oxides in the coating. Diffusion saturation of the surface with molecules and ions of compressed air activated by an electrical corona discharge has a
To establish the kinetics of wear of a complex tool of steel P18 with diffusion discrete coating in comparison with the control tool, extensive studies of the process of gear shaping were carried out. Studies of the kinetics and mechanisms of wear were carried out on a gear-shaping machine RCM-SN5F3. The objects of study were high-speed rams from P18 with geometry: m = 1,250 mm; z0 = 60; z = 30; d0 = 80; a = 6°; c = 5°. As the processed material – a gear wheel from steel 16X3HBU
Fig. 2. Microstructure of the surface after applying a diffusion discrete coating (increase 500) a) high-speed steel P18, b) – hard alloy BR10XOM.
Please cite this article as: E. Chekalova and A. Zhuravlev, Increasing the wear resistance of a complex profile cutting tool by applying a diffusion discrete coating, Materials Today: Proceedings, https://doi.org/10.1016/j.matpr.2019.08.053
E. Chekalova, A. Zhuravlev / Materials Today: Proceedings xxx (xxxx) xxx
3
Fig. 3. MSSA – spectrum carbide cutter VK10HOM: a – outside the coating; b – in the coating.
Table 1 Chemical composition of the hard alloy BR10XOM. Spectrum point
O
W
Co
Out of coverage In coating
4,68 14,72
85,7% 76,28%
9,62% 9,01%
Fig. 5. Efficiency of carbide mills BR10XOM when rough milling titanium blades BT6: n = 1020 ob/min, Sv = 490 mm/min, Sz = 0,08 mm/ob.
Thus, a cutting tool with a diffusion discrete coating can significantly increase the durability, reducing the tendency to loss of dimensional stability and elastic deflection when applying thermomechanical stresses arising during the cutting process. References
Fig. 4. Efficiency of high-speed P18 cutter with draft gearing of a steel part 16X3HBU
[1] L.G. Petrova, I.S. Belashova, V.A. Alexandrov, P.E. Demin, A.A. Brezhnev, J. Bull. Moscow Aviation Inst. 21 (2) (2014) 75–82 (in Russian). [2] V.P. Tabakov, Formation of wear-resistant ion-plasma coatings of the cutting tool, Mech. Eng. Moscow (2008) (in Russian). [3] E.A. Chekalova, Increasing the Durability of Cutting Tools and Heavily Loaded Parts by Applying a Diffusion Mesh Coating: A Monograph, Publishing House of the University of Mechanical Engineering, Moscow, 2014 (in Russian). [4] E.A. Chekalova, J. Electrometall. 8 (2015) 36–42 (in Russian). [5] E.A. Chekalova, P.D. Chekalov, Mag. News MSTU ‘‘MAMI” 1 (15) (2013) 113–118 (in Russian).
Please cite this article as: E. Chekalova and A. Zhuravlev, Increasing the wear resistance of a complex profile cutting tool by applying a diffusion discrete coating, Materials Today: Proceedings, https://doi.org/10.1016/j.matpr.2019.08.053
Contents lists available at ScienceDirect
Materials Today: Proceedings journal homepage: www.elsevier.com/locate/matpr
Increasing the wear resistance of a complex profile cutting tool by applying a diffusion discrete coating Elena Chekalova ⇑, Andrey Zhuravlev Moscow Polytechnic University, Moscow, 107023 Avtozavodskaya St. 16, Russia
a r t i c l e
i n f o
Article history: Received 8 July 2019 Accepted 2 August 2019 Available online xxxx Keywords: Composite profile cutting tool Corona discharge Wear resistance Diffusion discrete coating
a b s t r a c t A method for improving the wear resistance of a complex profile cutting tool by applying a diffusion discrete coating is proposed. The results of studies of a complex profile cutting tool on the wear rate of the cutting tool are presented. Ó 2019 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the International Conference on Modern Trends in Manufacturing Technologies and Equipment 2019.
In modern engineering production, more and more sophisticated automated machine tool equipment is being used. During the cutting process, the tool interacts with the material of the workpiece, which is accompanied by a complex set of physicochemical phenomena, namely, the surface layer is subjected to elastoplastic deformation [1]. Currently, there are various methods of applying coatings with different structures allowing to solve a number of tasks of technological operations of cutting, to increase productivity, accuracy and quality of processing. To increase the productivity of the tool, in the coating include alloying elements: Zr, Mo, Al, etc. in the form of soft layers, which affect the structure and physico-mechanical properties of coatings. Such an ambiguous change is associated with the different effects of chemical elements on the reduction of stresses acting on the instrumental basis [2]. Thus, to increase the wear resistance of the coated cutting tool and reduce premature wear, you can use the effect of uneven coating, i.e. coating by a diffusion discrete method, where the starting material is used as soft interlayers [3]. Such a coating structure can serve as an integral characteristic capable of preventing the propagation of cracks and even its stopping during operation at the interface of the tool material and the coating with a lower elastic modulus, which contributes to stress relaxation. It can be assumed that the unevenness of the coating ⇑ Corresponding author.
will contribute to an increase in tool resistance to deformation changes due to the independence of deformation damage of individual cells. This coating increases rigidity, but at the same time retains its strength, preventing surface spreading of cracks in the coating and reducing the elastic – plastic deformation under the influence of thermomechanical stresses, and, thereby, reduces the spread of cracks in the material [3]. Diffuse discrete coating can be different, since for each material the formation of the coating will have its own individual character (iron oxide for steel, tungsten oxide for a hard alloy), depending on the chemical composition of the material. The aim of the work is to study the wear resistance of a complex profile tool with a diffusion discrete coating. For coating, an experimental setup was developed (see Fig. 1), which consists of a ‘‘UIV-1” device with a unipolar positive crown and an electromechanical unit that performs the function of stepwise moving the nozzle. The device ‘‘UIV-1” is a nozzle, an ionizer that combines the organization of a directional air flow and its activation by positive ions. The CNC system monitors the process of step-by-step movements of the nozzle according to the program available on the CNC machine [3]. As a tool, the cutters of steel P18 and cutters made of carbide alloy BR10XOM with diffusion discrete coating were investigated. In the formation of an oxide coating obtained by a diffusion in a discrete manner, physical and chemical processes take place. The
E-mail address: [email protected] (E. Chekalova). https://doi.org/10.1016/j.matpr.2019.08.053 2214-7853/Ó 2019 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the International Conference on Modern Trends in Manufacturing Technologies and Equipment 2019.
Please cite this article as: E. Chekalova and A. Zhuravlev, Increasing the wear resistance of a complex profile cutting tool by applying a diffusion discrete coating, Materials Today: Proceedings, https://doi.org/10.1016/j.matpr.2019.08.053
2
E. Chekalova, A. Zhuravlev / Materials Today: Proceedings xxx (xxxx) xxx
significant advantage over saturation from the vapor-gas phase, because it has: – a high rate of saturation of the surface layer with molecules and ions of activated compressed air; – the possibility of obtaining processes of diffusion saturation regulated by the potential of the corona electrode (corona discharge current); – possibility of thermal diffusion surface saturation without additional depassivating treatment.
Fig. 1. Installation for applying a diffusion discrete coating.
characteristic microstructure of a diffusion discrete coating on tool materials is presented in Fig. 2. Studies in a scanning electron microscope have shown that the coating is a thin uneven epitaxial film and has a grain size of about 4 mm (see Fig. 2) [4,5]. X-ray microscopic analysis confirmed a significant decrease in the content of elements in a metal or alloy after coating, for example: for a hard alloy, the W content in the coating at a depth of 250 nm is 76.28%, while without coating – 85.7%; content of Co decreased slightly. At the same time, it was found that oxygen is present only in the surface layer of the coating, and its content is approximately 14.72% (see Fig. 3). In the coating on a carbide tool as a result of oxidation, predominantly tungsten oxides are formed: its concentration in the spectrum is significantly reduced (Table 1). Thus, it can be assumed that the decrease in the tungsten content in the surface layer is due to the oxidation process with the formation of tungsten oxides. Research confirms that tungsten oxides are part of the coating: tungsten trioxide WO3 (a); WO3 (b), WO3 (c); tungsten dioxide WO2 (d); and cobalt oxides (II, III) Co3O4 and cobalt oxide (II) CoO. In the course of metalphysical and metallographic studies, a coating thickness was obtained, which is approximately 350– 450 nm, while the hardness is 30% higher than the initial hardness. This increase in hardness is associated with the content of oxides in the coating. Diffusion saturation of the surface with molecules and ions of compressed air activated by an electrical corona discharge has a
To establish the kinetics of wear of a complex tool of steel P18 with diffusion discrete coating in comparison with the control tool, extensive studies of the process of gear shaping were carried out. Studies of the kinetics and mechanisms of wear were carried out on a gear-shaping machine RCM-SN5F3. The objects of study were high-speed rams from P18 with geometry: m = 1,250 mm; z0 = 60; z = 30; d0 = 80; a = 6°; c = 5°. As the processed material – a gear wheel from steel 16X3HBU
Fig. 2. Microstructure of the surface after applying a diffusion discrete coating (increase 500) a) high-speed steel P18, b) – hard alloy BR10XOM.
Please cite this article as: E. Chekalova and A. Zhuravlev, Increasing the wear resistance of a complex profile cutting tool by applying a diffusion discrete coating, Materials Today: Proceedings, https://doi.org/10.1016/j.matpr.2019.08.053
E. Chekalova, A. Zhuravlev / Materials Today: Proceedings xxx (xxxx) xxx
3
Fig. 3. MSSA – spectrum carbide cutter VK10HOM: a – outside the coating; b – in the coating.
Table 1 Chemical composition of the hard alloy BR10XOM. Spectrum point
O
W
Co
Out of coverage In coating
4,68 14,72
85,7% 76,28%
9,62% 9,01%
Fig. 5. Efficiency of carbide mills BR10XOM when rough milling titanium blades BT6: n = 1020 ob/min, Sv = 490 mm/min, Sz = 0,08 mm/ob.
Thus, a cutting tool with a diffusion discrete coating can significantly increase the durability, reducing the tendency to loss of dimensional stability and elastic deflection when applying thermomechanical stresses arising during the cutting process. References
Fig. 4. Efficiency of high-speed P18 cutter with draft gearing of a steel part 16X3HBU
[1] L.G. Petrova, I.S. Belashova, V.A. Alexandrov, P.E. Demin, A.A. Brezhnev, J. Bull. Moscow Aviation Inst. 21 (2) (2014) 75–82 (in Russian). [2] V.P. Tabakov, Formation of wear-resistant ion-plasma coatings of the cutting tool, Mech. Eng. Moscow (2008) (in Russian). [3] E.A. Chekalova, Increasing the Durability of Cutting Tools and Heavily Loaded Parts by Applying a Diffusion Mesh Coating: A Monograph, Publishing House of the University of Mechanical Engineering, Moscow, 2014 (in Russian). [4] E.A. Chekalova, J. Electrometall. 8 (2015) 36–42 (in Russian). [5] E.A. Chekalova, P.D. Chekalov, Mag. News MSTU ‘‘MAMI” 1 (15) (2013) 113–118 (in Russian).
Please cite this article as: E. Chekalova and A. Zhuravlev, Increasing the wear resistance of a complex profile cutting tool by applying a diffusion discrete coating, Materials Today: Proceedings, https://doi.org/10.1016/j.matpr.2019.08.053