Vol. 26 No. 4 2024 3 EDITORIAL COUNCIL EDITORIAL BOARD EDITOR-IN-CHIEF: Anatoliy A. Bataev, D.Sc. (Engineering), Professor, Rector, Novosibirsk State Technical University, Novosibirsk, Russian Federation DEPUTIES EDITOR-IN-CHIEF: Vladimir V. Ivancivsky, D.Sc. (Engineering), Associate Professor, Department of Industrial Machinery Design, Novosibirsk State Technical University, Novosibirsk, Russian Federation Vadim Y. Skeeba, Ph.D. (Engineering), Associate Professor, Department of Industrial Machinery Design, Novosibirsk State Technical University, Novosibirsk, Russian Federation Editor of the English translation: Elena A. Lozhkina, Ph.D. (Engineering), Department of Material Science in Mechanical Engineering, Novosibirsk State Technical University, Novosibirsk, Russian Federation The journal is issued since 1999 Publication frequency – 4 numbers a year Data on the journal are published in «Ulrich's Periodical Directory» Journal “Obrabotka Metallov” (“Metal Working and Material Science”) has been Indexed in Clarivate Analytics Services. Novosibirsk State Technical University, Prospekt K. Marksa, 20, Novosibirsk, 630073, Russia Tel.: +7 (383) 346-17-75 http://journals.nstu.ru/obrabotka_metallov E-mail: metal_working@mail.ru; metal_working@corp.nstu.ru Journal “Obrabotka Metallov – Metal Working and Material Science” is indexed in the world's largest abstracting bibliographic and scientometric databases Web of Science and Scopus. Journal “Obrabotka Metallov” (“Metal Working & Material Science”) has entered into an electronic licensing relationship with EBSCO Publishing, the world's leading aggregator of full text journals, magazines and eBooks. The full text of JOURNAL can be found in the EBSCOhost™ databases.
OBRABOTKAMETALLOV Vol. 26 No. 4 2024 4 EDITORIAL COUNCIL EDITORIAL COUNCIL CHAIRMAN: Nikolai V. Pustovoy, D.Sc. (Engineering), Professor, President, Novosibirsk State Technical University, Novosibirsk, Russian Federation MEMBERS: The Federative Republic of Brazil: Alberto Moreira Jorge Junior, Dr.-Ing., Full Professor; Federal University of São Carlos, São Carlos The Federal Republic of Germany: Moniko Greif, Dr.-Ing., Professor, Hochschule RheinMain University of Applied Sciences, Russelsheim Florian Nürnberger, Dr.-Ing., Chief Engineer and Head of the Department “Technology of Materials”, Leibniz Universität Hannover, Garbsen; Thomas Hassel, Dr.-Ing., Head of Underwater Technology Center Hanover, Leibniz Universität Hannover, Garbsen The Spain: Andrey L. Chuvilin, Ph.D. (Physics and Mathematics), Ikerbasque Research Professor, Head of Electron Microscopy Laboratory “CIC nanoGUNE”, San Sebastian The Republic of Belarus: Fyodor I. Panteleenko, D.Sc. (Engineering), Professor, First Vice-Rector, Corresponding Member of National Academy of Sciences of Belarus, Belarusian National Technical University, Minsk The Ukraine: Sergiy V. Kovalevskyy, D.Sc. (Engineering), Professor, Vice Rector for Research and Academic Aff airs, Donbass State Engineering Academy, Kramatorsk The Russian Federation: Vladimir G. Atapin, D.Sc. (Engineering), Professor, Novosibirsk State Technical University, Novosibirsk; Victor P. Balkov, Deputy general director, Research and Development Tooling Institute “VNIIINSTRUMENT”, Moscow; Vladimir A. Bataev, D.Sc. (Engineering), Professor, Novosibirsk State Technical University, Novosibirsk; Vladimir G. Burov, D.Sc. (Engineering), Professor, Novosibirsk State Technical University, Novosibirsk; Aleksandr N. Korotkov, D.Sc. (Engineering), Professor, Kuzbass State Technical University, Kemerovo; Dmitry V. Lobanov, D.Sc. (Engineering), Associate Professor, I.N. Ulianov Chuvash State University, Cheboksary; Aleksey V. Makarov, D.Sc. (Engineering), Corresponding Member of RAS, Head of division, Head of laboratory (Laboratory of Mechanical Properties) M.N. Miheev Institute of Metal Physics, Russian Academy of Sciences (Ural Branch), Yekaterinburg; Aleksandr G. Ovcharenko, D.Sc. (Engineering), Professor, Biysk Technological Institute, Biysk; Yuriy N. Saraev, D.Sc. (Engineering), Professor, V.P. Larionov Institute of the Physical-Technical Problems of the North of the Siberian Branch of the RAS, Yakutsk; Alexander S. Yanyushkin, D.Sc. (Engineering), Professor, I.N. Ulianov Chuvash State University, Cheboksary
Vol. 26 No. 4 2024 5 CONTENTS OBRABOTKAMETALLOV TECHNOLOGY Manikanta J.E., Ambhore N., Shamkuwar S., Gurajala N.K., Dakarapu S.R. Investigation of vegetable-based hybrid nanofl uids on machining performance in MQL turning........................................................................................... 6 Dama Y.B., Jogi B.F., Pawade R., Kulkarni A.P. Impact of print orientation on wear behavior in FDM printed PLA Biomaterial: Study for hip-joint implant...................................................................................................................... 19 GrinenkoA.V., ChumaevskyA.V., Sidorov E.A., Utyaganova V.R.,AmirovA.I., Kolubaev E.A. Geometry distortion, edge oxidation, structural changes and cut surface morphology of 100mm thick sheet product made of aluminum, copper and titanium alloys during reverse polarity plasma cutting...................................................................................... 41 Somatkar A., Dwivedi R., Chinchanikar S. Comparative evaluation of roller burnishing of Al6061-T6 alloy under dry and nanofl uid minimum quantity lubrication conditions............................................................................................... 57 Karlina Yu.I., Konyukhov V.Yu., Oparina T.A. Assessment of the quality and mechanical properties of metal layers from low-carbon steel obtained by the WAAM method with the use of additional using additional mechanical and ultrasonic processing..................................................................................................................................................... 75 EQUIPMENT. INSTRUMENTS Yusubov N.D., Abbasova H.M. Systematics of multi-tool setup on lathe group machines............................................... 92 Toshov J.B., Fozilov D.M., Yelemessov K.K., Ruziev U.N., Abdullayev D.N., Baskanbayeva D.D., Bekirova L.R. Increasing the durability of drill bit teeth by changing its manufacturing technology......................................................... 112 Pospelov I.D. Investigation of the distribution of normal contact stresses in deformation zone during hot rolling of strips made of structural low-alloy steels to increase the resistance of working rolls..................................................... 125 Ablyaz T.R., Blokhin V.B., Shlykov E.S., Muratov K.R., Osinnikov I.V. Manufacturing of tool electrodes with optimized confi guration for copy-piercing electrical discharge machining by rapid prototyping method.......................... 138 MATERIAL SCIENCE Shubert A.V., Konovalov S.V., Panchenko I.A. A review of research on high-entropy alloys, its properties, methods of creation and application.................................................................................................................................................. 153 Syusyuka E.N., Amineva E.H., Kabirov Yu.V., Prutsakova N.V. Analysis of changes in the microstructure of compression rings of an auxiliary marine engine.......................................................................................................... 180 Dudareva A.A., Bushueva E.G., Tyurin A.G., Domarov E.V., Nasennik I.E., Shikalov V.S., Skorokhod K.A., Legkodymov A.A. The eff ect of hot plastic deformation on the structure and properties of surface-modifi ed layers after non-vacuum electron beam surfacing of a powder mixture of composition 10Cr-30B on steel 0.12 C-18 Cr-9 Ni-Ti............................................................................................................................................................................. 192 Boltrushevich A.E., Martyushev N.V., Kozlov V.N., Kuznetsova Yu.S. Structure of Inconel 625 alloy blanks obtained by electric arc surfacing and electron beam surfacing........................................................................................... 206 Sablina T.Y., Panchenko M.Yu., Zyatikov I.A., Puchikin A.V., Konovalov I.N., Panchenko Yu.N. Study of surface hydrophilicity of metallic materials modifi ed by ultraviolet laser radiation........................................................................ 218 EDITORIALMATERIALS 234 FOUNDERS MATERIALS 243 CONTENTS
OBRABOTKAMETALLOV Vol. 26 No. 4 2024 TECHNOLOGY Impact of print orientation on wear behavior in FDM printed PLA Biomaterial: Study for hip-joint implant Yogiraj Dama 1, a, *, Bhagwan Jogi 1, b, Raju Pawade 1, c, Atul Kulkarni 2, d 1 Dr. Babasaheb Ambedkar Technological University, Lonere, Raigad, Maharashtra, 402103, India 2 Vishwakarma Institute of Information Technology, Survey No. 3/4, Kondhwa (Budruk), Maharashtra, Pune - 411048, India a https://orcid.org/0009-0008-5404-4347, yogirajdama@dbatu.ac.in; b https://orcid.org/0000-0003-2099-7533, bfjogi@dbatu.ac.in; c https://orcid.org/0000-0001-7239-625X, rspawade@dbatu.ac.in; d https://orcid.org/0000-0002-6452-6349, atul.kulkarni@viit.ac.in 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. 2024 vol. 26 no. 4 pp. 19–40 ISSN: 1994-6309 (print) / 2541-819X (online) DOI: 10.17212/1994-6309-2024-26.4-19-40 ART I CLE I NFO Article history: Received: 18 August 2024 Revised: 10 September 2024 Accepted: 17 September 2024 Available online: 15 December 2024 Keywords: 3D Printing Biomaterials FDM Implant Print orientation PLA Wear behavior ABSTRACT Introduction: hip joint replacement surgery involves replacing the damaged joint with an implant that can re-create the joint’s articulation functionality. 3D printing technology is more promising than the traditional manufacturing process when it comes to producing more complex parts and shapes. The goal of the current research project is to determine how quickly biomaterial implant can be manufactured using 3D printing for hip-joint replacement by studying the wear rate of parts manufactured using diff erent printing orientations. Although there are several additive manufacturing technologies, fuse deposition modeling (FDM) technology has had a signifi cant impact on healthcare, automotive industry, etc. This is mainly due to the adaptability of diff erent polymer-based composite materials and its cost-eff ectiveness. Such 3D printed polymers need to be further studied to evaluate the wear rate depending on diff erent 3D printing orientations. Polylactic acid (PLA) biomaterials were extensively studied to determine its suitability for use as hip joint materials. Purpose of the work: in this work, an experimental study was carried out on the eff ect of printing orientation on dry sliding wear of a polylactic acid (PLA) material obtained by fused deposition modeling (FDM) technology using the pin-on-disk (SS 316) scheme. In addition, experimental and empirical models are developed to predict the performance taking into account the infl uence of load and sliding speed. Grey relational analysis was used to determine the optimal parameters. The methods of investigation: the FDM printing was used to manufacture pins using diff erent printing orientations. Printing direction refers to printing at angles of 0°, 45°, and 90°, while all other 3D printing parameters remained unchanged. Wear testing was performed using the pin-on-disk kinematic scheme. During the experiments, the normal pin load and disk rotation speed were varied. The experiments were methodically designed to study the eff ect of input parameters on the specifi c wear rate. About 13 experiments were conducted for each printing orientation with a friction path of 4 kilometers, in the load range of 400–800 N, at a sliding speed of 450–750 rpm. Result and discussion: the study provides important results especially regarding the direction of 3D printing of components. It was found that the lowest sliding wear was observed for the pin printed at an angle of 0°, while slightly higher wear was observed for the pin printed at an angle of 90°. The layer bonding in the pin printed at an angle of 45° deformed under higher load, mainly due to an increase in temperature. The low bond strength in the pin printed at an angle of 45° resulted in high sliding wear. The optimal result was achieved at a sliding speed of 451 rpm and a load of 600 N. The results of the study are very useful for choosing materials for 3D printing of biomedical implants, medical and industrial products. For citation: Dama Y.B., Jogi B.F., Pawade R., Kulkarni A.P. Impact of print orientation on wear behavior in FDM printed PLA Biomaterial: Study for hip-joint implant. Obrabotka metallov (tekhnologiya, oborudovanie, instrumenty) = Metal Working and Material Science, 2024, vol. 26, no. 4, pp. 19–40. DOI: 10.17212/1994-6309-2024-26.4-19-40. (In Russian). ______ * Corresponding author Dama Yogiraj Basavraj, Research Scholar Dr. Babasaheb Ambedkar Technological University, Lonere, Raigad, 402103, Maharashtra, India Tel.: +91-9860384360, e-mail: yogirajdama@dbatu.ac.in Introduction In the medical domain, researchers are constantly trying to fi nd alternative biomaterials and manufacturing processes [1]. For the creation of more complex parts and shapes, 3D printing technology is more promising than conventional manufacturing methods. The 3D printing process, also called as additive
OBRABOTKAMETALLOV TECHNOLOGY Vol. 26 No. 4 2024 manufacturing process, has found wide application in the engineering domain, especially for the design of complex components and on-demand printing [2]. However, this technology has not yet proven itself in the medical domain due to many limitations such as availability of 3D printing biomaterials, printing orientations, regulatory approval, long-term reliability and the use of printed products in the patient’s body in real time etc., so researchers have focused on the use of 3D printing process for medical domain [1]. The hip-joint, and therefore the hip implant, is one of the most critical joints in the human body compared to any other joint. Despite signifi cant progress in the development of hip implants using various biomaterials including metal, ceramic and polymers, there is still much room for research and development of customized hip implants, even though biomaterials and hip replacement techniques have come a long way over the past few centuries. The hip joint connects the femoral bone to the pelvis, supporting the entire weight of the human body. The hip joint is one of the most important joints supporting the human body. The natural location of the acetabulum is a cup-shaped cavity into which the smooth spherical head of the femur fi ts precisely and subsequently slides. Strong ligaments surround the entire joint, providing stability. Innovations in design and materials over the last 50 years have signifi cantly reduced the actual wear rate of the most popular implants, which in turn allows us to signifi cantly reduce the risks associated with widespread dissemination of debris throughout the human body. Biomaterials such as ultra-high molecular weight polyethylene (UHMWPE), high-density polyethylene (HDPE), polyetheretherketone (PEEK) and others are commonly used in medicine for implant manufacture in a traditional way and are well proven [3–4]. Lewis [5] studied the properties of crosslinked ultra-highmolecular-weight polyethylene. Wang et al. found that the lubricity and wear properties of polyethylene in total joint replacement are improved [6]. Yousuf and Mohsin [7] studied the increase in the wear rate of high-density HDPE by adding ceramic particles. However, implanted polyethylene acetabular cups generate debris, which is reacted to by the body’s immune system [8]. To improve the mechanical and tribological characteristics of the HDPE matrix, nanocomposites including graphene, TiO2 nanoparticles and hybrid nanofi llers were added to it, which ultimately led to an increase in service life and a decrease in wear rate [9]. Zhang et al. [10] observed the use of PEEK as an alternative to CoCrMo in the femoral component of a total knee replacement. Hip fractures in the elderly are dangerous injuries that result in increased morbidity and mortality, disability, and signifi cant demand on medical resources. There is insuffi cient high-quality evidence to support the surgical strategy of hemiarthroplasty for the treatment of hip fractures [11]. Present study includes the PLA material for 3D printing of biomedical implants. Very few studies have reported data on PLA material used in hip implants. According to Tol et al. [11], a randomized clinical trial of 555 patients and an experiment of nature of 288 patients showed no diff erence in quality of life at six months post-injury between surgical interventions. Compared to DLA, PLA was associated with signifi cantly higher rates of reoperations and dislocations. In 2020, Obinna et al., [12] studied the 3D printing for hip implants. Bhagia S. et al. [13] reviewed the PLA biocomposites containing biomass resources and characterized it as biodegradable, recyclable, and off ering potential for biomass-derived fuel, electricity, heat and chemicals process and FDM printing. For FDM technology, Prashant Anerao [14] conducted a parametric study on the mechanical properties of biochar-reinforced PLA composite. A comparative study and analysis of hearing aid housings printed from diff erent biomaterials was conducted [15]. Using ANSYS explicit workbench, a comparative study of various polymer materials was conducted at fi ve diff erent drop impact test velocities. According to the study, TPU deformed to a maximum at all velocities, more than PLA or ABS [15]. Dama et al. [16] pointed out the suitability of the additive manufacturing process for reproducing design features. However, these materials are not suitable for 3D printing in a format that is accessible for conventional manufacturing processes. Fused deposition modeling (FDM) 3D printing, also called fused fi lament fabrication (FFF), is an additive manufacturing (AM) technique. Molten material is selectively applied along a predetermined route to build parts layer by layer. Thermoplastic polymers in the form of fi laments are used to create the fi nal physical products. Daly et al. conducted a parametric study and observed the eff ects of several 3D printing factors including
OBRABOTKAMETALLOV Vol. 26 No. 4 2024 TECHNOLOGY printing orientation, speed, and discretization method (layer by layer or fi lament) on warpage, residual stress, defl ection, and mechanical behavior [17]. Sandanamsamy et al. examined the FDM printing process parameters on the tensile properties of PLA materials [18]. Meltem [19] studied the eff ects of FDM printing orientation on the tensile properties and printing time of a PLA part. The tensile strength decreased when the printing orientation of the parts was changed from horizontal to vertical and from 0° to 90° print angle (Figure 1). The tensile strength of the vertically printed part was 36 % lower than that of the horizontally printed part due to the load direction and failure mode. a b Fig. 1. FDM printing parameters: a – printing orientations; b – raster direction angle equal to 0° and layer thickness. Source: (Chacón et al. [20]) To ensure consistent and high-quality results, advanced manufacturing processes like fused deposition modeling (FDM) are being implemented in enterprises globally. For this reason, it is essential to understand how the various components interact and how it aff ects the quality of the fi nal form. Wear behavior analysis of PLA parts has many applications in biomedicine, prosthetics, tissue engineering, and other industries. The 3D printed PLA biomaterial needs to be thoroughly investigated for its potential use as a hip arthroplasty material through wear behavior and mechanical properties analysis. The purpose of the work: This study examined the eff ect of printing orientation on the wear behavior of PLA biomaterial obtained by fused deposition modeling (FDM) under dry sliding friction conditions using the pin-on-disk (SS 316) scheme. In order to forecast the performance of both empirical and experimentally obtained models, the eff ect of sliding speed and load was taken into account. The grey relational analysis was used to determine the ideal parameters. The FDM 3D printing and wear testing equipment available at the Department of Mechanical Engineering, Vishwakarma Institute of Information Technology, Pune, Maharashtra, India was used in the study. Further research is focused on the wear behavior study using composite materials to improve the wear rate performance [21–27]. 3D printing of composite biomaterial can be used to develop an implant with higher stability. Investigation Technique The pin-on-disc tribometer is a proven device for analyzing sliding wear and wear characteristics of the material. The working principle of the pin-on-disc tribometer is that the disk rotates at a constant speed while the pin remains stationary under a given load, and wear starts due to the relative motion between the pin and the disk. A linear variable diff erential transducer (LVDT) is used at the other end of the setup to record the displacement. This machine measures the coeffi cient of friction, friction force, wear rate,
OBRABOTKAMETALLOV TECHNOLOGY Vol. 26 No. 4 2024 temperature, wear volume etc. The pin-on-disk tribometer schematic diagram is shown in Fig. 2, a, and the device used for the experiments is shown in Fig. 2, b. The machine operates at load range from 100 N to 800 N and rpm range from 20 rpm to 2,000 rpm. The measurement accuracy of the LVDT is 1 ± 1 % when measuring wear in μm and the smallest value is 1 μm. The test was carried out in accordance with ASTM G 99. Fused deposition modeling (FDM) is one of the popular 3D printing techniques that uses thermoplastic polymers to create complex 3D structures. It allows for the clean and cost-eff ective creation of small functional parts. A wide variety of materials such as PLA, nylon, ABS, PTFE etc., with diff erent process parameters can be used to print complex objects. During the printing process, thermoplastic fi laments are melted and extruded through a heated nozzle, after which they are applied in a semi-solid state to a solid substrate. The schematic process diagram is shown in Fig. 3, a. The pins were printed using a Flashforge Dreamer NX 3D printer and a PLA material. Fig. 3, b shows a photograph of the 3D printer used to print the pins. All pins were produced at a fi ll density of 100 %, an extrusion temperature of 220 °C, a raster angle a b Fig. 2. Schematic diagram of the pin-on-disk tribometer (a); Experimental setup of the pin-on-disk tribometer (b) a b Fig. 3. FDM printing scheme (a) and FDM 3D printer (Flashforge-Dreamer NX) (b)
OBRABOTKAMETALLOV Vol. 26 No. 4 2024 TECHNOLOGY Ta b l e 1 Values of parameters selected for the experiment Parameters Minimum value Maximum value Normal load (N) 400 800 Speed (rpm) 450 750 Sliding distance 4 km of 90°, and a layer thickness of 0.2 mm. According to the literature, these parameters are optimal. The test specimens were cylindrical PLA pins with a diameter of 8 mm and a length of 40 mm. These pins were printed at the printing orientation of 0°, 45° and 90°. PLA material is one of the popular fi lament materials used in FDM printing. PLA is easy to print and the printer can be easily adjusted to it. The experiments were methodically designed to study the infl uence of input parameters on specifi c wear rate. Sliding velocities were obtained by selecting the track diameter on the disk and the corresponding rotation speed of the disk. SS 316 stainless steel was chosen as the material for the disk.About 13 experiments were carried out for each printing orientation with a friction path of 4 kilometers. These were prepared based on the central compositional design (CCD) which is the eff ective design for experiments (DOE) for the RSM method. Table 1 shows the parameter values selected for the experiment. In this study, the grey relational analysis was used to optimize the parameters that ensure minimal sliding wear. The grey system theory presents the degree of grey correlation to describe the degree of correlation in the developing trends of diff erent things or diff erent factors. The greater the degree of grey correlation, the more similar the things are, and vice versa. This theory transforms a multiple response optimization problem into a single response optimization situation with the objective function of overall grey relational grade [27]. Methodology of grey analysis The procedure for obtaining the solution of GRA optimization is given as follows: Step 1. To identify input parameters that infl uence the multiple output variables. Step 2. To select of Taguchi design matrix and conduct the experiments. Step 3. To select quality characteristics for each output variable. Step 4. To normalize all response variables (grey relational generation): the smaller-the-better normalization formula was used to transfer the original sequence to a comparable sequence and is given below. (o) (o) * (o) (o) ( ) ( ) ( ) ( ) ( max . max i ) m n i i i i i x k x k x k x k x k − = − Step 5. To determine the deviation Sequences, Δ0i(k) The deviation sequence, Δ0i(k) is the absolute diff erence between the reference sequence x0∙(k) and the comparability sequence xi∙(k) after normalization. The value of x0∙(k) was considered equal to 1. 0 ( ) Þ 0 ( ) Þ ( ) . i k x k xi k Δ = ⋅ − ⋅ Step 6. To calculate the grey relational coeffi cient (GRC) for each output: grey relational coeffi cient. γ(x_0 (k),x_i (k)) ( ) max max 0 0 m ( ) ( ) ( ) in , . i i x k x k k Δ +ζΔ γ = Δ +ζΔ
OBRABOTKAMETALLOV TECHNOLOGY Vol. 26 No. 4 2024 Step 7. To calculate the grey relational grade by mean value of GRCs: grey relational grade is an average sum of the grey relational coeffi cient, which is defi ned as follows: ( ) 0 1 0( ) ( , , ) 1 . m i i i x x x k x k m = γ( ) = γ ∑ Step 8. To determine the optimal parameters. Step 9. To predict the grey relational grade when setting optimal parameters. Results and Discussion The sliding wear study of PLA material on SS 316 steel disc was carried out using a pin-on-disc friction machine. In this machine, a seesaw arrangement was made by attaching a rod to transfer the normal load to the pin by attaching weights to the other end. LVDT sensor was used to detect the change in displacement due to material wear. The rotation speed of the disk was varied by selecting an appropriate track diameter. The test was carried out on a 4 kilometer track distance (approx. 18 to 22 minutes). A control panel was attached to the machine, as well as a computer that displayed the speed, friction force andwear for the relevant processing parameters. Windcom software was used to show the variation in wear and friction force with respect to test time and track distance of 5 km. Figure 4 shows the wear track image of PO1, PO2 and PO3 formed on the SS 316 disc. The pins were manufactured using the FDM technology with printing orientations of 0°, 45° and 90°. Hereinafter, the pins manufactured with a printing orientation angle of 0°, 45° and 90° will be referred to as PO1, PO2 and PO3 respectively. The printing orientation of the pins in the form of a CAD model and in real printing is shown in Fig. 5, a and b respectively. The experiments were performed according to DOE and the sliding wear was recorded for diff erent values of normal load and sliding velocity. The experimental results along with the wear track images for all tests are summarized in Tables 2 and 3. All required environmental conditions were constant for all experimental tests. A mathematical equation based on the power law was used to predict the wear by considering the normal load (N) and speed (rpm) and is Fig. 4. Image of wear tracks of FDM printed pins on a SS 316 stainless steel disc a b Fig. 5. 3D printing orientation: a – CAD model; b – printed pins
OBRABOTKAMETALLOV Vol. 26 No. 4 2024 TECHNOLOGY Ta b l e 2 Experimental results of testing pins with diff erent printing directions Expt. No Printing Orientation Normal Load (N) Speed (rpm) Wear (μm) 1 PO1 800 600 2,394 2 PO1 600 451 2,178 3 PO1 459 494 2,234 4 PO1 600 600 2,398 5 PO1 741 494 2,367 6 PO1 741 706 2,429 7 PO1 401 600 2,208 8 PO1 600 600 2,320 9 PO1 600 600 2,398 10 PO1 600 600 2,367 11 PO1 459 706 2,214 12 PO1 600 750 2,391 13 PO1 600 600 2,502 14 PO2 800 600 3,293 15 PO2 600 451 3,101 16 PO2 459 494 2,877 17 PO2 600 600 3,267 18 PO2 741 494 3,012 19 PO2 741 706 3,539 20 PO2 401 600 2,896 21 PO2 600 600 3,106 22 PO2 600 600 3,148 23 PO2 600 600 3,178 24 PO2 459 706 3,273 25 PO2 600 750 3,388 26 PO2 600 600 3,147 27 PO3 800 600 3,012 28 PO3 600 451 2,683 29 PO3 459 494 2,598 30 PO3 600 600 2,796 31 PO3 741 494 2,825 32 PO3 741 706 3,201 33 PO3 401 600 2,575 34 PO3 600 600 2,867 35 PO3 600 600 2,864 36 PO3 600 600 2,854 37 PO3 459 706 2,701 38 PO3 600 750 3,056 39 PO3 600 600 2,910
OBRABOTKAMETALLOV TECHNOLOGY Vol. 26 No. 4 2024 Ta b l e 3 Image of wear tracks for each test Expt. No Printing Orientation Wear track image Printing Orientation Wear track image Printing Orientation Wear track image 1 PO1 PO2 PO3 2 PO1 PO2 PO3 3 PO1 PO2 PO3 4 PO1 PO2 PO3 5 PO1 PO2 PO3 6 PO1 PO2 PO3 7 PO1 PO2 PO3 8 PO1 PO2 PO3 9 PO1 PO2 PO3
OBRABOTKAMETALLOV Vol. 26 No. 4 2024 TECHNOLOGY Expt. No Printing Orientation Wear track image Printing Orientation Wear track image Printing Orientation Wear track image 10 PO1 PO2 PO3 11 PO1 PO2 PO3 12 PO1 PO2 PO3 13 PO1 PO2 PO3 T h e E n d Ta b l e 3 given in Eq. 1. The power law is generally used to understand the infl uence of multiple input parameters on the output response. , b c N W a F S = ⋅ ⋅ (1) where FN and S is normal load and speed respectively; a, b and c are the constants. The values of these constants were determined for PO1, PO2 and PO3 using the experimental results. The mathematical equations for the FDM printed materials PO1, PO2 and PO3 are given in Table 4. Data fi t software was used to determine the correlation between wear, normal load and speed. The coeffi cient of correlation (R2) was found to be 0.9244, 0.928 and 0.95 for PO1, PO2 and PO3. This showed that the developed empirical equation can be used to determine the material wear under friction against a SS 316 steel disc within the selected parameter. It is evident from the exponent of all equations that speed has a greater eff ect on wear compared to the normal load. 2D and 3D graphs were prepared to better understand the wear pattern. The loss of material is caused by wear, which eventually occurs due to the relative motion of two surfaces. Unlike friction, there is no energy loss. Polymers typically exhibit abrasive, adhesive, and fatigue wear mechanisms. Polymers tend to form a fi lm that is transferred to the counterbody, Ta b l e 4 Mathematical equations Printing Orientation Equation PO1 0.11 0.16 432.8 N W F S = ⋅ ⋅ PO2 0.18 0.23 234.9 N W F S = ⋅ ⋅ PO3 0.22 0.27 123.5 N W F S = ⋅ ⋅
OBRABOTKAMETALLOV TECHNOLOGY Vol. 26 No. 4 2024 Fig. 6. Formation of the transfer fi lm a b Fig. 7. Eff ect of normal load (a) and speed (b) on PO1 wear which minimizes wear, so polymers are often chosen as a material for wearing parts. This is one of the important tribological phenomena. It is also known that when separation occurs inside the transfer fi lm, it occurs between the fi lm and the polymer rather than between the polymer and steel, so it acts as a protective layer that minimizes wear. The adhesive wear mechanism is one of the reasons for the development of the transfer fi lm in polymer. A schematic diagram of the transfer fi lm formation is shown in Fig. 6. PLA is one of the popular materials because of its non-toxicity, biodegradability, biocompatibility and eco-friendliness. Additionally, since it is a 3D printing material, it is highly appreciated in biomedical applications where there are relative motions between two surfaces (such as hip, knee and other joints). It has been reported in the literature that the printing orientation angle also plays an important role in the wear behavior of PLA material. In the present study, PO1, PO2 and PO3 pins were manufactured using additive technology with constant and optimized parameters reported in the literature so that the printing uniformity can be maintained. The eff ects of normal load and speed as well as printing angle on the wear behavior were studied. Figure 7, a and b show the eff ects of normal load and speed on the wear pattern of PO1 pin (print orientation angle 0°). A gradual increase in the wear was observed under normal load and variable speed. The minimum wear was recorded as 2,291 μm and the maximum was recorded as 2,523 μm. From Fig. 7, a and b, it can be seen that the slope of the wear versus speed graph increased by almost 43 % compared with that of the normal load versus wear graph. This indicates that the speed has a prominent eff ect on the wear pattern. This was also evident from the exponent values of the equation (PO1) given in Table 4. As the speed increases, the vibrations in the system increase, which is an unfavorable condition for forming a stable transfer fi lm. Fig. 8, a and b shows the eff ects of normal load and speed on the wear pattern for the PO2 pin (print orientation angle of 45°). The minimum wear of 2,948 μm and the maximum wear of 3,489 μm (Fig. 8, a and b) showed that the slope of the wear versus speed graph increased by almost 26 % compared to the slope of the wear versus normal load graph. The wear of PO2 is greater compared to PO1 in the considered cases. This was due to the improper bonding of the material at a printing otation angle of 45°. A similar fact was also reported in the literature.
OBRABOTKAMETALLOV Vol. 26 No. 4 2024 TECHNOLOGY a b Fig. 8. Eff ect of normal load (a) and speed (b) on PO2 wear a b Fig. 9. Eff ect of normal load (a) and speed (b) on PO3 wear Figure 9, a and b shows the infl uence of normal load and speed on the wear pattern for PO3 pin (printing orientation angle of 90°). A gradual increase in the wear was observed under normal load and variable speed. The minimum wear was recorded as 2,538 μm and the maximum wear was recorded as 3,106 μm. It is obvious from Figure 9, a and b that the slope of the wear versus speed graph increased by almost 21 % compared with that of the wear versus normal load graph. This indicates that the speed has a prominent eff ect on the wear pattern. A similar conclusion could be drawn from the exponent values of the equation (PO1) given in Table 4. It is observed form that above fi gures that PO1 material shows lower wear followed by PO3. PO2 exhibited the highest wear. The wear of FDM-printed PLA is greatly infl uenced by speed than normal load. A comparative analysis of the wear of all specimens was performed by maintaining a constant speed and a constant load. The equation given in Table 4 was used to determine the wear at the corresponding constant load. The eff ect of normal load on the wear pattern of specimens PO1, PO2 and PO3 at a constant speed of 600 rpm and the eff ect of speed on the wear pattern of specimens PO1, PO2 and PO3 at a constant normal load of 600 N are shown in Figure 10, a and b, respectively. The load varied from 400 N to 800 N with a constant increment of 50 N. It was observed that at constant speed of 600 rpm, PO1 material exhibited lower wear compared to PO2 and PO3. The lowest wear value for PO1 was 2,328 μm, while the highest was 2,513 μm. For PO2, the lowest wear value was 3,008 μm, and the highest was 3,407 μm. For PO3, the lowest wear value was 2,595 μm, while the highest was 3,023 μm. The wear rate increased steadily, increasing by 1.08, 1.25, and 1.11 times with increasing load for PO1, PO2, and PO3 specimens, respectively. PO1 exhibited a more stable wear pattern compared to PO2 and PO3. This was mainly due to the formation of a stable transfer
OBRABOTKAMETALLOV TECHNOLOGY Vol. 26 No. 4 2024 fi lm, which is clearly observed in the wear track images of the PO1 material shown in Table 3. The better performance of the PO1 was also attributed to the FDM printing orientation direction angle (i.e. 0°). In addition, the PO1 material (as shown in Fig. 11) with a printing orientation angle of 0° showed excellent tensile and compressive strength, primarily because the printing orientation was aligned with the load application direction. In this position, the material layers have a constant thickness and a longer length in the PO1 direction, which is likely to improve the bonding between the material layers, ultimately reducing wear. In addition, in the case of PO2 and PO3 materials, the printing orientation angle was 45° and normal to the loading direction. The layer adhesion is aff ected by the load and heat generated during operation [14]. As a result, a stable transfer fi lm is not formed. This is also confi rmed by the wear track images for PO2 and PO3 materials shown in Table 3. In the case of PO2, an uneven transfer fi lm was observed, resulting in poor wear resistance. It should also be noted that the layer adhesion was poor in the specimens produced with a printing orientation angle of 30–60° [14, 26]. The schematic diagram of the printing orientation and direction of normal load acting on the pin during the test is shown in Fig. 11. The fi gure shows that in the case of PO2 material, the load acting on the pin is further divided into two components. The horizontal component tries to weaken the bonding between the layers, causing vibration in the system; and because of this a stable transfer fi lm is not formed, which leads to greater wear of PO2. In case of PO2, this phenomenon was not observed so the effi ciency of PO3 was higher than that of PO2. However, it should be noted that the bond strength is less in printing situation of PO3 compared to PO1, so its effi ciency is lower than that of PO1. The values of normal load and speed in the equation from Table 4 for materials PO1, PO2 and PO3 indicate that wear is more dependent on normal load than on sliding speed. In order to have a clear understanding of the infl uence of the input parameters on wear, 3-D graphs of wear were plotted using the empirical equation given in Table 4 varying with normal load and sliding speed. The 3-D surface curves were plotted by varying the two process parameters simultaneously while keeping the third parameter constant in the middle value of the parameter ranges as shown in Table 1. The 3-D graphs refl ecting the variation in the wear are shown in Fig. 12, a–c. Fig. 12, a, b, c depict the variation in the wear with the normal load and speed for PO1, PO2 and PO3 Fig. 11. Schematic diagram of the printing orientation and the direction of application of the normal load acting on the pin during testing a b Fig. 10. Eff ect of normal load at constant speed of 600 rpm (a) and eff ect of speed at constant normal load of 600 N (b) on wear behavior of PO1, PO2 and PO3 specimens
OBRABOTKAMETALLOV Vol. 26 No. 4 2024 TECHNOLOGY respectively. The graphs are based on varying two process parameters while keeping the third parameter constant. The study revealed the infl uence of the interaction of process parameters and the printing orientation angle on the wear rate of PLA in a friction pair with SS 316 stainless steel. It is seen that the wear increases with the increase of speed and normal load. However, the increase in wear will become more noticeable at higher process parameters. The speed followed by normal load can be seen as most signifi cant parameters aff ecting wear. This can also be confi rmed by the higher exponent value for the speed followed by for load Table 4. This study fi nds that wear is prominently aff ected by speed, especially at higher values of normal load. Grey relational analysis is the multi response optimization method that has been applied in the performance evaluation of various complex applications with limited information. It is widely used to measure the degree of relationship between sequences using gray relational grade. The procedure for GRA is explained above in the methodology. In the present study, the input factors were normal load and speed whereas GRA was conducted for the wear of PO1, PO2 and PO3 materials. The linear normalization of the experimental results for wear was based on the smaller-the-better approach. The experiments were conducted for diff erent input parameters according to Table 1 for PO1, PO2 and PO3 specimen. A total of 39 experiments were conducted, of which 1–13 experiments were for PO1, 14–26 for PO2 and the rest were for PO3. According to the procedure of GRA normalization of response (xi∙(k)), the deviation sequence (Δ0i) and the gray relation coeffi cient (GRC) for wear were determined. The values of xi∙(k), Δ0i and GRC for wear are shown in Table 5. A higher GRC indicates that the corresponding experimental conditions are optimal. Overall, PO1 material showed excellent performance compared with PO2 and PO3. However, PO2 showed poor performance. The optimal values of normal load and speed were found to be 600 N and 451 rpm. PLA Fig. 12. 3-D graphs showing the change in wear depending on the normal load and rotation speed for: a – PO1; b – PO2 and c – PO3
OBRABOTKAMETALLOV TECHNOLOGY Vol. 26 No. 4 2024 Ta b l e 5 GRC values for all experiments Expt. No Orientation Wear (μm) Xi∙(k) 0i GRC 1 PO1 2,394 0.84 0.16 0.758 2 PO1 2,178 1 0 1 3 PO1 2,234 0.96 0.04 0.926 4 PO1 2,398 0.84 0.16 0.758 5 PO1 2,367 0.86 0.14 0.781 6 PO1 2,429 0.82 0.18 0.735 7 PO1 2,208 0.98 0.02 0.962 8 PO1 2,320 0.9 0.1 0.833 9 PO1 2,398 0.84 0.16 0.758 10 PO1 2,367 0.86 0.14 0.781 11 PO1 2,214 0.97 0.03 0.943 12 PO1 2,391 0.84 0.16 0.758 13 PO1 2,502 0.76 0.24 0.676 14 PO2 3,293 0.18 0.82 0.379 15 PO2 3,101 0.32 0.68 0.424 16 PO2 2,877 0.49 0.51 0.495 17 PO2 3,267 0.2 0.8 0.385 18 PO2 3,012 0.39 0.61 0.45 19 PO2 3,539 0 1 0.333 20 PO2 2,896 0.47 0.53 0.485 21 PO2 3,106 0.32 0.68 0.424 22 PO2 3,148 0.29 0.71 0.413 23 PO2 3,178 0.27 0.73 0.407 24 PO2 3,273 0.2 0.8 0.385 25 PO2 3,388 0.11 0.89 0.36 26 PO2 3,147 0.29 0.71 0.413 27 PO3 3,012 0.39 0.61 0.45 28 PO3 2,683 0.63 0.37 0.575 29 PO3 2,598 0.69 0.31 0.617 30 PO3 2,796 0.55 0.45 0.526 31 PO3 2,825 0.52 0.48 0.51 32 PO3 3,201 0.25 0.75 0.4 33 PO3 2,575 0.71 0.29 0.633 34 PO3 2,867 0.49 0.51 0.495 35 PO3 2,864 0.5 0.5 0.5 36 PO3 2,854 0.5 0.5 0.5 37 PO3 2,701 0.62 0.38 0.568 38 PO3 3,056 0.35 0.65 0.435 39 PO3 2,910 0.46 0.54 0.481
OBRABOTKAMETALLOV Vol. 26 No. 4 2024 TECHNOLOGY components printed by FDM with a printing orientation angle of 0° are most suitable for parts susceptible to wear, followed by components with a printing orientation angle of 90°. Components manufactured with a printing orientation angle of 45° should not be applied. Conclusion This study demonstrates the wear characteristics of PLA material in a friction pair with SS 316 stainless steel to determine the optimal parameters. FDM printing was used to create the specimens with diff erent printing orientation (0°, 45°, 90°). The experiments were conducted using the pin-on-disk friction scheme under diff erent load and speed. Based on the experiment, a mathematical model was developed. In addition, grey relational analysis, a multi response optimization method, was used to determine optimal parameters. The uniqueness of this method is that it is used to evaluate the performance of various complex systems with insuffi cient information. The following are the conclusions drawn from the study: ● The study of PLA material obtained by FDM with diff erent printing orientation shows that horizontally printed pins have less wear than vertically printed ones. The greatest wear is characteristic of pins printed at an angle of 45°. ● It is noted that wear is signifi cantly aff ected by speed followed by load. This is also confi rmed by higher exponent values for speed and followed by load. A noticeable increase in wear is observed at higher process parameters. ● The PLA specimen printed by FDM with a printing orientation angle of 0° (PO1) exhibit less wear followed by specimen with printing orientation angle of 90° (PO3). This is mainly due to the high layer bonds strength along the printing orientation for PO1. The specimen with a printing orientation angle of 45° (PO2) exhibit poor wear resistance due to thermal softening. The optimal parameters for PO1 are found to be 600 N load and 451 rpm, which was determined using the multi variable grey relational analysis method. ● In the developed experimental mathematical model, the correlation coeffi cient (R2) is found to be 0.9244, 0.928 and 0.95 for PO1, PO2 and PO3. These models can be used to predict the wear of FDM printed PLA material in a friction pair with SS 316 stainless steel. ● The results of the study will be useful in 3D printing PLA biomaterial for hip joint application. References 1. Ventola C.L. Medical applications for 3D printing: current and projected uses. Pharmacy and Therapeutics Journal: Peer Review, 2014, vol. 39 (10), pp. 704–711. 2. Gibson I., Rosen D., Stucker B. Direct digital manufacturing. Additive Manufacturing Technologies. 2nd ed. New York, Springer, 2015, pp. 375–397. DOI: 10.1007/978-1-4939-2113-3_16. 3. Patil N.A., Njuguna J., Kandasubramanian B. UHMWPE for biomedical applications: performance and functionalization. European Polymer Journal, 2020, vol. 125, p. 09529. DOI: 10.1016/j.eurpolymj.2020.109529. 4. Kurtz S.M. Primer on UHMWPE. UHMWPE biomaterials handbook: ultra-high molecular weight polyethylene in total joint replacement and medical. 3rd ed. Amsterdam, Elsevier, 2016, pp. 1–6. 5. Lewis G. Properties of crosslinked ultra-high-molecular-weight polyethylene. Biomaterials, 2001, vol. 22 (4), pp. 371–401. DOI: 10.1016/S0142-9612(00)00195-2. 6. Wang A., Essner A., Polineni V., Stark C., Dumbleton J. Lubrication and wear of ultra-high molecular weight polyethylene in total joint replacements. Tribology International, 1998, vol. 31, pp. 17–33. DOI: 10.1016/S0301679X (98)00005-X. 7. Yousuf J.M., Mohsin A.A. Enhancing wear rate of high-density polyethylene (HDPE) by adding ceramic particles to propose an option for artifi cial hip joint liner. IOP Conference Series: Materials Science and Engineering, 2019, vol. 561, p. 012071. DOI: 10.1088/1757-899X/561/1/012071. 8. Orishimo K.F., Claus A.M., Sychterz C.J., Engh C.A. Relationship between polyethylene wear and osteolysis in hips with a second-generation porous-coated cementless cup after seven years of follow-up. The Journal of Bone & Joint Surgery, 2003, vol. 85 (6), pp. 1095–1099. DOI: 10.2106/00004623-200306000-00018.
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