Vol. 27 No. 1 2025 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. 27 No. 1 2025 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. 27 No. 1 2025 5 CONTENTS OBRABOTKAMETALLOV TECHNOLOGY Umerov E.D., Skakun V.V., Dzhemalyadinov R.M., Egorov Y.A. Investigation of the eff ect of oil-based MWFs with enhanced tribological properties on cutting forces and roughness of the processed surfaces.............................................. 6 Manikanta J.E., Ambhore N., Thellaputta G.R. Investigation of vegetable oil-based cutting fl uids enhanced with nanoparticle additions in turning operations........................................................................................................................ 20 Shlykov E.S., Ablyaz T.R., Blokhin V.B., Muratov K.R. Improvement the manufacturing quality of new generation heat-resistant nickel alloy products using wire electrical discharge machining................................................................... 34 Ablyaz T.R., Osinnikov I.V., Shlykov E.S., Kamenskikh A.A., Gorohov A.Yu., Kropanev N.A., Muratov K.R. Prediction of changes in the surface layer during copy-piercing electrical discharge machining....................................... 48 Martyushev N.V., Kozlov V.N., Boltrushevich A.E., Kuznetsova Yu.S., Bovkun A.S. Milling of Inconel 625 blanks fabricated by wire arc additive manufacturing (WAAM)..................................................................................................... 61 Fatyukhin D.S., Nigmetzyanov R.I., Prikhodko V.M., Sundukov S.K., Sukhov A.V. Infl uence of the oscillating systems inclination angle on the surface properties of steel 45 during ultrasonic surface plastic deformation................... 77 EQUIPMENT. INSTRUMENTS Borisov M.A., Lobanov D.V., Skeeba V.Y., Nadezhdina O.A. Development of a device for studying and simulating the electrochemical grinding process................................................................................................................................... 93 Lapshin V.P., Gubanova A.A., Dudinov I.O. Predicting machined surface quality under conditions of increasing tool wear............................................................................................................................................................................... 106 Podgornyj Y.I., Skeeba V.Y., Martynova T.G., Sadykin A.V., Martyushev N.V., Lobanov D.V., Pelemeshko A.K., Popkov A.S. Designing the homogenization mechanism.................................................................................................... 129 MATERIAL SCIENCE Usanova O.Yu., Ryazantseva A.V., Vakhrusheva M.Yu., Modina M.A., Kuznetsova Yu.S. Improving the performance characteristics of grey cast iron parts via ion implantation.......................................................................... 143 Abdelaziz K., Saber D. Fabrication and characterization of Al-7Si alloy matrix nanocomposite by stir casting technique using multi-wall thickness steel mold................................................................................................................ 155 Dama Y.B., Jogi B.F., Pawade R., Pal S., Gaikwad Y.M. DLP 3D printing and characterization of PEEK-acrylate composite biomaterials for hip-joint implants....................................................................................................................... 172 Prudnikov A.N., Galachieva S.V., Absadykov B.N., Sharipzyanova G.Kh., Tsyganko E.N., Ivancivsky V.V. Eff ect of deformation thermocyclic treatment and normalizing on the mechanical properties of sheet Steel 10.......................... 192 Bhanavase V., Jogi B.F., Dama Y.B. Wear behavior study of glass fi ber and organic clay reinforced poly-phenylenesulfi de (PPS) composites material........................................................................................................................................ 203 EDITORIALMATERIALS 218 FOUNDERS MATERIALS 227 CONTENTS
OBRABOTKAMETALLOV MATERIAL SCIENCE Vol. 27 No. 1 2025 DLP 3D printing and characterization of PEEK-acrylate composite biomaterials for hip-joint implants Yogiraj Dama 1, a, *, Bhagwan Jogi 1, b, Raju Pawade 1, c, Shibam Pal 2, d, Yogesh Gaikwad 2, e 1 Dr. Babasaheb Ambedkar Technological University, Lonere, Raigad, Maharashtra, 402103, India 2 CSIR-National Chemical Laboratory, Pashan Pune, Maharashtra, 411008, 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/0000-0002-3681-5039, shibampal123456@gmail.com; e https://orcid.org/0009-0003-3211-0861, ym.gaikwad@ncl.res.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. 2025 vol. 27 no. 1 pp. 172–191 ISSN: 1994-6309 (print) / 2541-819X (online) DOI: 10.17212/1994-6309-2025-27.1-172-191 ART I CLE I NFO Article history: Received: 26 November 2024 Revised: 14 December 2024 Accepted: 06 January 2025 Available online: 15 March 2025 Keywords: 3D Printing Biomaterials FDM Implant Print orientation PLA Wear behavior ABSTRACT Introduction. Hip joint replacement is considered the most complex and critically important orthopedic surgical procedure compared to knee and shoulder joint replacements. Over the past few decades, there has been significant advancement in hip joint replacement technology, and various biomaterials have been substantially improved. An increasing number of hip joint replacement surgeries are now successful, assisting individuals in regaining normal daily activity and work capacity comparable to their prefracture state. However, the need for revision surgery, specifically for implant replacement, is still observed in active patients several years following the initial operation. This underscores the need to develop durable biomaterials and customized hip joint implants to reduce implant wear and the risk of dislocation. This research study explores a novel PEEK-in-acrylate composite biomaterial with varied weight percentages of PEEK (0 %, 5 %, and 10 %) in an acrylate-based matrix. Tests were conducted to determine its properties, biocompatibility, and 3D printability. Based on the developed material, pins (in accordance with the ASTM standard) were fabricated using 3D printing for subsequent wear rate studies. The potential use of the developed composite materials for hip-joint applications was also thoroughly investigated. The purpose of this study is to develop and investigate a new PEEK in Acrylate composite biomaterial with varied weight percentages of PEEK (0 %, 5 %, and 10 %) in an acrylate-based matrix. The research includes an assessment of the material’s properties, biocompatibility, and 3D printability. Using digital light processing (DLP) 3D printing technology at room temperature, pins (in accordance with the ASTM standard) were fabricated. An experimental study of dry sliding wear resistance was conducted on the resulting samples to determine the effect of PEEK weight fraction on the wear rate and frictional performance against an SS 316 steel disk. Scanning electron microscopy (SEM) and Energy-dispersive X-ray spectroscopy (EDS) were used to analyze the surface structure and element distribution within the material. The Methods of Investigation. Digital Light Processing (DLP) 3D Printing technique was used to 3D Print the ASTM pins andAcetabular liner with different weight fraction of PEEK in acrylate. Dry sliding wear tests were carried out using a pin-on-disk tribometer. During testing, the disk rotation speed and the normal load on the pin were varied. The studies were designed to determine the influence of input parameters on the wear rate. A total of nine experiments were conducted for each PEEK weight fraction, with a sliding distance of 4 km per experiment. The load ranged from 20 to 100 N, and the sliding speed varied from 450 to 750 rpm. Surface structure and element distribution were analyzed by Energy-dispersive X-ray spectroscopy (EDS) and Scanning electron microscopy (SEM). Result and Discussion. Current study demonstrates the advantages of varying the weight fraction of PEEK in Acrylate for DLP-fabricated biomaterials. Analysis of the SEM, EDS, and wear testing results indicated that the composite with 10 wt % PEEK in Acrylate exhibited superior microstructural integrity, elemental homogeneity, and significantly improved wear resistance. The 10 wt % PEEK in Acrylate composite, fabricated via DLP 3D printing, is suitable for biomedical implant and healthcare applications For citation: Dama Y.B., Jogi B.F., Pawade R., Pal S., Gaikwad Y.M. DLP 3D printing and characterization of PEEK-acrylate composite biomaterials for hip-joint implants. Obrabotka metallov (tekhnologiya, oborudovanie, instrumenty) = Metal Working and Material Science, 2025, vol. 27, no. 1, pp. 172–191. DOI: 10.17212/1994-6309-2025-27.1-172-191. (In Russian). ______ * Corresponding author Jogi Bhagwan Fatru, Professor Dr. Babasaheb Ambedkar Technological University, Lonere, Raigad, 402103, Maharashtra, India Tel.: +91 942-116-6370, e-mail: bfjogi@dbatu.ac.in Introduction Hip joint implants play a key role in contemporary orthopedic surgery and are extensively used for the treatment of conditions such as osteoarthritis, rheumatoid arthritis, hip fractures, and congenital deformities [1]. These implants are designed to replace damaged hip joints, restore locomotor function, and reduce pain [2]. Due to their critical function in supporting body weight and enabling movement, materials for
OBRABOTKAMETALLOV MATERIAL SCIENCE Vol. 27 No. 1 2025 hip implants must possess superior mechanical properties, biocompatibility, and durability [3]. Additive Manufacturing (AM), or 3D printing, has fundamentally transformed biomedical engineering by enabling the creation of complex geometries and personalized implants tailored to individual patient anatomy [4]. In particular, additive manufacturing techniques facilitate the use of porous titanium alloys, which promotes improved osseointegration and minimizes stiffness mismatch between the implant and bone, thereby ensuring favorable long-term patient outcomes [5]. The present study evaluates the mechanical properties, biocompatibility, and overall effectiveness of hip joint implants fabricated from both traditional materials and using additive manufacturing technologies [6]. The aim of this work is to investigate the potential of additive manufacturing to improve patient outcomes by overcoming the limitations inherent in conventional implants, such as stress shielding and insufficient bone integration [7]. Among the wide range of polymer biomaterials, polyetheretherketone (PEEK) stands out due to its suitability for 3Dprinting, surpassing other materials used in orthopedic implantology [8]. PEEK is employed in conventional manufacturing processes to develop various biomedical implants [9]. It is characterized by high strength and a Young’s modulus closely matching that of human bone, which minimizes stress shielding and enhances implant stability. Due to these properties, PEEK is a promising material for the fabrication of load-bearing components, such as hip joint cups [10]. PEEK possesses high thermal stability, with a melting point of approximately 343 °C. This allows it to withstand sterilization processes required for medical implants without degradation, ensuring the retention of its properties throughout its lifespan within the human body [11]. Furthermore, PEEK exhibits exceptional chemical resistance to a variety of chemical substances, including solvents, acids, and bases, ensuring its durability and long-term stability in the physiological environment without eliciting adverse reactions [12]. The biocompatibility of PEEK as a reliable material for biomedical applications has been validated by numerous studies [13–14]. For an adequate assessment of PEEK’s applicability in load-bearing orthopedic implants, mechanical testing and wear resistance studies are of paramount importance. Specifically, Reddy et al. [15] investigated the mechanical properties of 3D-printed PEEK specimens intended for dental implants and found that specimens printed with a (45°/−45°) raster angle exhibited improved tensile, compressive, and flexural strength. This indicates the potential of PEEK as an alternative to titanium and zirconia for dental applications. In their studies of a PEEK-Ti6Al4V composite implant, Zhang et al. [16] assessed compressive strength and wear resistance via mechanical testing, in accordance with standard ASTM testing protocols. Du et al. [17] investigated the mechanical characteristics of scaffolds made from the PEEK-SiN composite material. Scanning electron microscopy (SEM) analysis of PEEK implants provides valuable insights into the surface morphology and microstructural features of the material. For example, Lim et al. in 2019 [18] utilized SEM analysis to evaluate the porosity of various 3D-printed PEEK and titanium structures. The results indicated that a pore size of approximately 1.2 mm most closely matches the structure of human trabecular bone. This optimal pore size has been proven to enhance osseointegration, as SEM images demonstrate that the rough surface texture of porous structures promotes increased pull-out strength and, overall, improved bone integration capability [19]. Conversely, SEM analysis conducted by Carpenter et al. in 2018 [20] revealed significant differences between porous PEEK and porous titanium implants. In 2020, Virpe et al. [21] performed an analysis of polymer composites, demonstrating the successful incorporation of carbon fillers into a PLA matrix using FDM 3D-printing. At the same time, the correlation between microstructural characteristics, as determined by SEM, and their influence on wear mechanisms in pin-on-disc testing remains inadequately understood [22–23]. It is noted that not all polymer biomaterials, such as UHMWPE, HDPE, and PE, are readily amenable to 3D printing. This necessitates the use of alternative polymers, including PEEK, PLA, and composite polymer biomaterials that are suitable for 3D-printing and meet the requirements for implants [24]. Therefore, investigating the wear rate characteristics of hip joint implants is an important task, leading to further research on wear parameters using various polymer biomaterials, composites, and coated biomaterials [25]. Various testing methods employed for evaluating the wear resistance and mechanical properties of polymer materials are useful for biomaterials as well [27–28].
OBRABOTKAMETALLOV MATERIAL SCIENCE Vol. 27 No. 1 2025 The purpose of this research is to study a PEEK in Acrylate polymer-based biomaterial for hip-joint implant applications, which is 3D-printable at room temperature [26]. The study aims to determine the impact of reinforcement levels on microstructural integrity, elemental distribution, and wear performance, thereby aiding in the development of PEEK-based materials for orthopedic applications. Specifically, 3D-printed ASTM pins will be tested via pin-on-disc methodology to evaluate wear rate performance suitable for the long-term sustainability of implants. Digital light processing (DLP) 3D-printing was conducted at the National Chemical Laboratory (NCL), Pune, Maharashtra, India. Wear testing was performed using equipment available at the Mechanical Engineering Department of VIIT, Pune, Maharashtra, India. Methods Material Preparation Composite material formulations included 0 wt. %, 5 wt. %, and 10 wt. % PEEK in an Acrylatebased matrix. The composite resins were prepared by mixing the PEEK with the Acrylate resin at varying PEEK concentrations (5 wt. % and 10 wt. %). Fig. 1 illustrates the process flow for preparing the resin for 3D-printing and subsequently fabricating physical objects via 3D-printing. The resin pre-processing involved dissolving reactive diluents, such as Tricyclo[5.2.1.02-6]decane dimethanol diacrylate (TCDDA), Ethoxylated bisphenol A dimethacrylate (BPAEDMA), and photoinitiators, in the resin binder. The resulting resin mixture was then loaded into a DLP 3D-printer, where the printing process was initiated through layer-by-layer curing of the material. In Digital light processing (DLP) 3D-printing, as depicted in Fig. 2, a, a digital projector is used to project an image of the entire layer of the object being printed onto the surface of a vat containing liquid photopolymer resin. Upon exposure to the projected image, selective solidification of the photopolymer resin occurs, conforming to the shape of the layer. After each layer is cured, the build platform is raised, separating the formed layer from the resin vat, and a volumetric 3D model of the object is built. A washing and post-curing machine is used to clean the resulting part and to achieve final polymerization of the resin (Fig. 2, b). The PEEK in Acrylate composite biomaterial was used to 3D-print ASTM-compliant pins and a final liner implant. Fig. 1. Material preparation methodology used in the study [26]
OBRABOTKAMETALLOV MATERIAL SCIENCE Vol. 27 No. 1 2025 a b Fig. 2. DLP 3D Printing method: DLP 3DPrint (a), Wash and Cure Machine (b) The initial layer curing time was 30 seconds, followed by 10 seconds for each subsequent layer. ASTMcompliant pins (10 mm diameter and 15 mm height) were printed under controlled conditions to ensure uniform size and shape. Scanning electron microscopy (SEM) To enhance the electrical conductivity of non-metallic samples, a thin layer of gold (Au) was applied to the surface using a sputtering method. The gold layer, approximately 10 nm thick, was deposited using an ion sputtering device. This step is necessary to minimize charging effects that can occur during SEM analysis, which can lead to image distortions and reduced resolution. Gold was selected due to its high electrical conductivity and minimal interaction with the electron beam. The operating principle of the Zeus SEM instrument is illustrated in Fig. 3. SEM analysis was performed using a Zeus field-emission scanning electron microscope, which is characterized by high resolution and versatility in materials science. The microscope’s operating accelerating voltage was 20 kV. This voltage value was chosen as an optimal compromise between the need for high-resolution imaging and ensuring sufficient penetration depth of the electron beam into the sample material. The use of lower voltages may be insufficient for penetration, Fig. 3. Working principle of scanning electron microscope (SEM)
OBRABOTKAMETALLOV MATERIAL SCIENCE Vol. 27 No. 1 2025 particularly in the case of composite materials with non-uniform density distribution, which would limit the analysis depth. A schematic of the experimental setup used for SEM analysis is shown in Fig. 3. Sample images were acquired at various magnifications: 500×, 1,000×, 2,000×, and 5,000×. Lower magnifications were utilized to examine the overall surface morphology and to identify macroscopic defects, such as cracks, pores, and the distribution of reinforcing particles. Higher magnifications were employed to analyze microstructural details, including the interfacial boundary between the PEEK matrix and reinforcing particles, the morphology of individual particles, and micro-defects (micro-cracks, pores) that could negatively affect the mechanical properties of the material. In this study, energy dispersive spectroscopy (EDS) and scanning electron microscopy (SEM) were employed to investigate the microstructural features, surface morphology, and elemental composition of the materials under investigation: pure acrylate (base material), a composite with 5 wt. % PEEK in Acrylate, and a composite with 10 wt. % PEEK in Acrylate [28]. These methods are essential for understanding the distribution of PEEK reinforcing particleswithinAcrylatematrix and for identifying potentialmicrostructural defects that may influence the material’s performance in biomedical applications. Sample preparation for SEM analysis is crucial to obtain high-quality images and reliable data. Samples were sectioned into small fragments of ~10×10 mm to ensure proper accommodation within the SEM chamber. These sections were then subjected to sequential polishing, initially ground with silicon carbide paper of varying grit sizes (from 320 grit for coarse material removal to 1,200 grit for fine polishing). After achieving a smooth surface, diamond paste (3 μm, followed by 1 μm) was used to create a mirror-like finish. This final polishing step is critically important as it reduces surface roughness, which minimizes artifacts during SEM imaging. Energy dispersive spectroscopy (EDS) For detailed elemental analysis of the samples in conjunction with SEM, the energy dispersive X-ray spectroscopy (EDS) method was employed. The EDS method is based on the identification of characteristic X-ray radiation emitted by the sample when it is bombarded with an electron beam from a scanning electron microscope (SEM). The energy of these X-rays is specific to each element present in the sample, enabling their identification and quantification. For a comprehensive assessment of the material composition, EDS analysis was performed in multiple regions of each sample. In particular, point analysis was used to determine the elemental composition in selected local areas, primarily within the reinforcing particles and the PEEK matrix. A schematic of the EDS Instrument is shown in Fig. 4. Fig. 4. Schematic representation of working principle of EDS instrument
OBRABOTKAMETALLOV MATERIAL SCIENCE Vol. 27 No. 1 2025 Ta b l e 1 Summary of SEM and EDS Conditions Parameter Value Accelerating Voltage 20 kV Magnification Range 500×, 1000×, 2000×, 5000× Coating Material Gold (Au), ~10 nm thickness EDS Analysis Elemental mapping and point analysis Furthermore, elemental mapping was performed on larger areas to visualize the distribution of elements across the sample. This technique proved particularly useful for evaluating the uniformity of reinforcing particle distribution within the PEEK matrix. Analysis of the EDS spectra provided important data on the presence of carbon (C) and oxygen (O) as the primary elements of PEEK, as well as other elements introduced by the reinforcing particles. The homogeneity of the composites was assessed by comparing the elemental distribution in various analyzed regions. Significant deviations in the elemental composition indicated segregation or clustering of the reinforcing particles, which can influence the mechanical properties of the composite materials. The summary of SEM and EDS conditions is tabulated in Table 1. Fig. 5. Experimental test set up used for wear testing study Pin-on-Disk wear testing To evaluate the wear resistance of polyetheretherketone (PEEK) materials, including base Acrylate material, Acrylate composites with 5 wt. % PEEK, and Acrylate composites with 10 wt. % PEEK, a pin-ondisk wear test was performed. Test specimens were cylindrical pins machined from each type of material, with dimensions of 8 mm in diameter and 40 mm in height. To ensure smooth and uniform contact with the disk during testing, the pin surfaces were polished using silicon carbide abrasive paper followed by diamond paste. The wear tests were conducted on a tribometer configured in a pin-on-disk arrangement. A schematic of the test setup is shown in Fig. 5 and includes a dead weight for applying a constant load to the pin, a motor for rotating the disk, and a counterbody (SS 316 stainless steel) in the form of a disk with a surface roughness of 0.1 μm to provide a controlled and consistent contact surface. To ensure reproducibility of results and maintain uniform testing conditions, all experimental parameters were standardized. A normal load of 10 N was applied to each pin using dead weights. The disk was rotated at a constant sliding speed of 1 m/s to simulate wear conditions representative of orthopedic implants. The duration of each test corresponded to a total sliding distance of 1,000 m, to ensure that sufficient wear data
OBRABOTKAMETALLOV MATERIAL SCIENCE Vol. 27 No. 1 2025 Ta b l e 2 Summary of Pin-on-Disk Testing Conditions Parameter Value Pin Material 5 % wt. PEEK in Acrylate, 10 % wt. PEEK in Acrylate Disk Material SS 316 Normal Load 10 N Sliding Speed 1 m/s Sliding Distance 1,000 was collected. The tribometer was pre-calibrated to ensure high accuracy in maintaining the applied load, sliding speed, and disk rotation speed. During the test, the vertically mounted pins exerted constant pressure against the rotating stainless steel disk, inducing wear as a result of sliding contact. After completion of the tests, the worn surfaces of the pins were analyzed using scanning electron microscopy (SEM) to investigate the wear mechanisms and surface degradation patterns of each PEEK composite material. Particular attention was given to the surface morphology to establish a relationship between reinforcement level and wear performance. The key parameters of the pin-on-disk wear tests (materials, load, speed, and sliding distance) are summarized in Table 2. Results and Discussion A3D-printed PEEK inAcrylate composite biomaterial was thoroughly examined for its suitability in hip hip-joint applications. As part of this research, a novel biomaterial — a PEEK inAcrylate composite —was developed, incorporating varying PEEK content (0 wt. %, 5 wt. %, and 10 wt. %) in Acrylate base material. Tests were conducted to determine the material properties, biocompatibility, and 3D-printability. ASTM standard pins were fabricated using digital light processing (DLP) 3D-printing at room temperature. An experimental study of wear under dry sliding friction conditions was performed on the PEEK composites with varying percentage concentrations within the Acrylate. An SS 316 steel disk was used as the counterbody. The objective of the tests was to assess the effect of PEEK content on the wear resistance and wear rate. Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) techniques were employed to analyze the surface structure and elemental composition of the materials. The results and conclusions obtained from the SEM and EDS analyses and the wear tests are presented below. Characterization of the base acrylate material Surface morphology and microstructural features The baseAcrylate material was investigated using scanning electronmicroscopy (SEM) at magnifications ranging from 500× to 5,000× (see Fig. 6, a, b, and c) with an accelerating voltage of 20 kV. Imaging settings were selected for detailed analysis of the surface structure and microscopic characteristics of the material, enabling the identification of both large-scale and small-scale features. SEM images acquired at 500× magnification revealed a predominantly smooth surface small ripples evenly distributed throughout the material. The smooth surface morphology of this polymer indicates a high-quality manufacturing process and the absence of macroscopic defects such as voids or inclusions. At magnifications of 1,000× and 2,000×, the surface texture became more pronounced, revealing features mainly in the 1–2 μm size range. These features are likely due to the polymer composition, which can lead to slight variations in surface texture that arise during processing. The even distribution of these features suggests deliberate material processing, resulting in a homogenous surface that increases its mechanical durability. When magnified up to 5,000×, the microstructure of the material became more discernible (see Fig. 6, c). The SEM images revealed a smooth and homogenous texture without any visible crystalline formations,
OBRABOTKAMETALLOV MATERIAL SCIENCE Vol. 27 No. 1 2025 indicating a predominantly amorphous structure of the base material. The absence of observable crystalline domains suggests that the material is specifically designed for applications requiring flexibility and impact resistance, which are often associated with amorphous polymers. EDS Analysis and Elemental Composition The results of EDS analysis for the base Acrylate material are presented in Figs. 7, a and 7, b. The EDS investigation enabled quantitative determination of the elemental composition of the base material, revealing that it primarily consists of carbon (C) and oxygen (O). In one region, the elemental composition was determined to be approximately 71.17 wt. % carbon and approximately 28.83 wt .% oxygen; in another region, approximately 72.21 wt. % carbon and approximately 27.79 wt. % oxygen. The composition of substances was determined as 76.68 wt. % carbon and 23.32 wt. % oxygen, and 77.59 wt. % carbon and 22.41 wt. % oxygen, respectively. a b c Fig. 6. SEM images for base Acrylate material at different magnification: a – 100× magnification, 200 µm; b – 2,000× magnification, 10 µm; c – 5,000× magnification; 5 µm a b Fig. 7. EDS analysis for base Acrylate material: a – spectrum with 70 µm; b – EDS graph for 70 µm Spectrum The high carbon content is a characteristic feature of polymer materials, in which carbon plays the role of the primary structural element, as also shown in Fig. 7, b. The detected oxygen is likely associated with the presence of functional groups such as carbonyl (C=O) or ether (C-O-C) groups, which are characteristic of polymers, such as PEEK (polyetheretherketone). These groups contribute to enhanced thermal stability and chemical resistance of the material, improving its performance characteristics in demanding applications.
OBRABOTKAMETALLOV MATERIAL SCIENCE Vol. 27 No. 1 2025 Characterisation of 5 % wt. PEEK Material in Acrylate Surface Morphology and Microstructural Features SEM images of 5 % wt. PEEK material in Acrylate, acquired at various magnifications, are presented in Figs. 8, a, b, and c. Analysis of the composite material using scanning electron microscopy was performed to investigate its surface morphology and microstructure. Magnifications ranging from 500× to 5,000× at an accelerating voltage of 20 kV were used. This range enabled a comprehensive evaluation of both general surface characteristics and microstructural features and provided valuable information regarding the effect of PEEK addition to the underlying polymer matrix (Fig. 8, a). a b c Fig. 8. SEM images for 5 wt. % PEEK in Acrylate material at different magnification: a – 500× magnification, 50 µm; b – 2,000× magnification, 10 µm; c – 5,000× magnification, 5 µm At 500× magnification, the SEM images exhibit a relatively smooth and homogenous surface with minimal deviations, comparable to those of the base material. However, the addition of PEEK resulted in slight changes in the surface texture. These changes are likely due to the dispersion of PEEK within the polymer matrix. Amore detailed investigation of the material’s microstructure was conducted at magnifications of 1,000× and 2,000×. The PEEK particles are visible as separate and relatively evenly distributed phases within the matrix. Their sizes are in the micron range, ranging from 1 to 2 μm. The observed distribution indicates effective PEEK incorporation into the matrix, contributing to the composite’s homogeneity. At a maximum magnification of 5,000×, images were obtained that demonstrate a more detailed view of the PEEK distribution. The PEEK particles are characterized by excellent dispersion and seamless integration into the polymer matrix without noticeable signs of aggregation. The addition of PEEK does not disrupt the predominantly amorphous structure of the material, which is important for maintaining its natural flexibility and toughness. Overall, the surface retains an amorphous appearance. EDS Analysis and elemental composition Energy dispersive spectroscopy (EDS) examination of the 5 wt. % polyetheretherketone (PEEK) in Acrylate revealed that its elemental composition is predominantly carbon (C) and oxygen (O), consistent with the composition of the base Acrylate material (Fig. 9). Table 3 presents the data on the composition of 5 % wt. PEEK in Acrylate composites material. The mass percentage of carbon was approximately 70.75 %, while that of oxygen was 29.25 %. The atomic proportions of the elements are 76.32% for carbon and 23.68% for oxygen. These results indicate a similarity in the elemental composition between the base Acrylate material and the PEEK composite, suggesting a negligible influence of PEEK addition on the overall elemental composition. The slight increase in oxygen content is attributed to the presence of oxygen-rich functional groups in PEEK (such as ether and carbonyl groups), which are uniformly distributed within the polymeric matrix.
OBRABOTKAMETALLOV MATERIAL SCIENCE Vol. 27 No. 1 2025 а b Fig. 9. EDS analysis for 5 wt. % PEEK in Acrylate material: а – spectrum with 70 µm; b – EDS graph for 70 µm spectrum Ta b l e 3 Composition of 5 % wt. PEEK in Acrylate composites material Element Weight (%) Atomic (%) C 70.75 76.32 O 29.25 23.68 Totals 100.00 – As evidenced by the SEM images, the incorporation of 5 wt. % PEEK into the polymeric matrix leads to the formation of characteristic microstructural features. The uniform distribution of the PEEK particles within the matrix contributes to enhanced mechanical properties of the material, such as stiffness and strength, through reinforcement of the polymer structure. Despite the PEEK addition, the composite retains a predominantly amorphous structure, which is favorable for maintaining important characteristics such as impact toughness. The EDS data confirm that the elemental composition of the composite largely remains unchanged, with carbon and oxygen being predominant. The slight increase in oxygen concentration indicates successful PEEK integration into the matrix, suggesting the absence of significant phase separation and inhomogenuity. Characterization of 10 % wt. PEEK Material in Acrylate Surface Morphology and Microstructural Features The morphology and microstructure of a composite material containing 10 wt. % PEEK were investigated using scanning electron microscopy (SEM) at magnifications ranging from 500× to 5,000× and an accelerating voltage of 20 kV (Fig. 10, a, b, c). This approach enabled a detailed examination of the material’s surface morphology and microstructure, as well as an evaluation of the impact of the increased PEEK content on its structure.
OBRABOTKAMETALLOV MATERIAL SCIENCE Vol. 27 No. 1 2025 а b c Fig. 10. SEM images for 10 wt. % PEEK in Acrylate material at different magnification: а – 500× magnification, 50 µm; b – 2,000× magnification, 10 µm; c – 5,000× magnification, 5 µm At 500× magnification, the material’s surface exhibited a relatively smooth texture, comparable to materials containing a lower concentration of PEEK. However, the higher PEEK concentration led to more pronounced differences in the texture, indicating a significant influence of the PEEK particles on the surface composition. The observed changes were subtle but consistent, suggesting a uniform distribution of PEEK within the matrix (Fig. 10, b). Increasing the magnification to 2000× made the PEEK particles more visibile. They were observed as discrete inclusions within the polymer matrix, with a size of approximately 1–2 μm. The distribution pattern indicates good integration of PEEK into the base material, promoting enhanced structural homogeneity and, consequently, improved mechanical properties of the composite. At 5,000× magnification (Fig. 10, c), the SEM images provided more detailed information about the microstructural features, confirming the uniform distribution of PEEK particles and the absence of aggregation. The surface maintained an amorphous structure, with the presence of PEEK contributing to minor variations in texture that did not disrupt the overall smoothness of the material. This homogeneous component distribution is critical for achieving an optimal balance of flexibility and strength, which is necessary for the intended application of this material. EDS Analysis and elemental composition EDS analysis provided precise and quantitative data regarding the elemental composition of the 10 wt. % PEEK material. The primary elements identified were carbon (C) and oxygen (O), consistent with the composition of PEEK and the base polymer (Fig. 11). Table 4 presents the elemental composition of 10 wt. % PEEK in Acrylate. The substance in a specific area consisted of approximately 70.19 wt. % carbon and 29.81 wt. % oxygen. In other locations, additional а b Fig. 11. EDS analysis for 10 wt. % PEEK in Acrylate material: а – spectrum with 70 µm; b – EDS graph for 70 µm spectrum
OBRABOTKAMETALLOV MATERIAL SCIENCE Vol. 27 No. 1 2025 elements, such as gold (Au), were observed, which were applied onto the surface to improve image contrast. The elemental distribution confirms that the presence of PEEK does not significantly affect the base composition, but introduces functional groups associated with the chemical structure of PEEK. Fluctuations in oxygen levels in different locations may be related to the presence of these functional groups, which are important for PEEK properties, including its thermal stability and resistance to harsh environments. The data from scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) collectively show that the addition of 10 wt. % PEEK to the base material has a significant impact on the microstructure, especially compared to lower PEEK concentrations. SEM images show a uniform distribution of PEEK particles, which, in turn, leads to an increase in mechanical properties such as stiffness and tensile strength. This improvement in mechanical properties can be explained by the reinforcing action of the particles within the polymer matrix. The inherent amorphous structure of the material, which is maintained even at the higher PEEK concentration, is advantageous for maintaining its flexibility and impact toughness. EDS analysis confirms these findings, demonstrating that the composition of the material mainly corresponds to the composition of PEEK, with carbon and oxygen being the main components. The inclusion of PEEK particles does not lead to significant phase separation, thereby maintaining a homogeneous structure in the composite. Discussion: The incorporation of PEEK into the Acrylate polymer matrix at concentrations of 5 wt. % or 10 wt. % enhances the mechanical properties of the material by reinforcing the structure, while the material maintains flexibility and surface smoothness. These composites possess a balanced combination of strength, durability, and adaptability, making them optimal candidates for applications where these characteristics are essential. The choice between 5 wt. % and 10 wt. % PEEK content will depend on the specific mechanical property requirements of the material based on the intended application, where higher PEEK concentrations will provide increased stiffness and strength. Wear testing results The results of pin-on-disc wear tests conducted on samples of base Acrylate, a 5 wt. % PEEK in Acrylate composite, and a 10 wt. % PEEK in Acrylate composite clearly demonstrate the impact of PEEK reinforcement on the wear resistance and frictional properties of Acrylate. Table 5 presents the experimental observations obtained during the pin-on-disc wear tests. A systematic analysis of friction coefficients, wear rates, and SEM images of the worn surfaces clearly shows the benefits of PEEK reinforcement for improving the tribological properties in applications where the material is subjected to loads. The wear test results demonstrate a pronounced relationship between the degree of reinforcement, wear resistance, and frictional characteristics for the base Acrylate, a 5 wt. % PEEK in Acrylate composite, and a 10 wt. % PEEK in Acrylate composite. The base Acrylate exhibited a friction coefficient of 0.45 and the highest wear rate, measured at 1.2×10−6 mm3/N⋅m. SEM analysis of the base Acrylate surface revealed visible wear tracks and significant material removal, indicating its limited wear resistance, which is expected for an unreinforced polymer. The friction coefficient for the 5 wt. % PEEK inAcrylate composite decreased to 0.40, and the wear rate decreased to 0.9×10−6 mm3/ N⋅m. SEM images of the 5 wt. % PEEK composite surface showed improved uniformity and moderate wear tracks, indicating that the introduction of 5 wt. % reinforcing particles enhances the material’s structural integrity and, consequently, its wear resistance. Ta b l e 4 Composition of 10 % wt. PEEK in Acrylate composites material Element Weight (%) Atomic (%) C 70.19 75.82 O 29.81 24.18 Totals 100.00 –
OBRABOTKAMETALLOV MATERIAL SCIENCE Vol. 27 No. 1 2025 Ta b l e 5 Experimental Observation Table for Pin-on-Disk Wear Test Material Type Normal Load (N) Sliding Speed (m/s) Sliding Distance (m) Wear Rate (mm3/N∙m) Coefficient of Friction SEM observations Base Acrylate 10 1 1,000 1.2 × 10−6 0.45 Smooth surface with slight wear tracks; minor material removal observed 5 % wt. PEEK in Acrylate composites 10 1 1,000 0.9 × 10−6 0.4 Increased uniformity: moderate wear marks but reduced material loss compared to base Acrylate 10 % wt. PEEK in Acrylate composites 10 1 1,000 0.7 × 10−6 0.35 Enhanced surface homogeneity; minimal wear tracks, indicating higher wear resistance The 10 wt. % PEEK in Acrylate composite demonstrated the best wear resistance among the tested materials, with a wear rate of 0.7×10−6 mm3/N⋅m and a friction coefficient of 0.35. SEM images of the 10 wt. % PEEK in Acrylate composite surface revealed high uniformity and minimal wear tracks, indicating a significant improvement in wear resistance at this reinforcing component concentration. This improvement is likely due to the uniform distribution of reinforcing particles, which effectively prevents material degradation under friction and load. Increasing the degree of reinforcement from base Acrylate to the 10 wt. % PEEK composite leads to an improvement in both wear resistance and frictional properties. This indicates that increasing the degree of reinforcement enhances the structural integrity of the composite, reducing erosion and friction under highload conditions. Fig. 12 shows a liner fabricated via DLP 3D-printing from the 10 wt. % PEEK in Acrylate composite biomaterial. This allows for the conclusion that the 10 wt. % PEEK in Acrylate biomaterial is suitable for 3D-printing at room temperature in order to obtain the desired geometry for orthopedic implants. Fig. 12. DLP 3D-printed hip joint implant liner made from Acrylate composite with 10 wt % PEEK
OBRABOTKAMETALLOV MATERIAL SCIENCE Vol. 27 No. 1 2025 Conclusion This study highlights the advanced properties of 10 wt. % PEEK in Acrylate composites biomaterials, demonstrating their enhanced wear resistance and improved mechanical properties compared to Acrylate composites with lower PEEK content and base Acrylate materials. – The 10 wt. % PEEK in Acrylate composites biomaterial possesses an optimal balance of strength, stiffness, and ductility, which is critical for load-bearing applications such as orthopedic implants. Pin-on-disc wear tests showed a significant reduction in the specific wear rate of the 10 wt. % PEEK in Acrylate composite at various loads and speeds, confirming its suitability for use in high-stress environments. – SEM and EDS studies confirmed the uniform distribution of PEEK particles within the polymer matrix, which ensures improved mechanical properties and durability of the composite material. – The ability of the 10 wt. % PEEK in Acrylate composite to maintain mechanical integrity under harsh tribological conditions makes it a promising material for long-term applications in orthopedics, particularly in joint implants where wear resistance and mechanical characteristics are crucial for successful implantation. – The improved wear resistance and enhanced mechanical strength of this composite reduce the risk of implant failure due to material degradation, which is an important factor determining the lifespan of hipjoint implants. – The 10 wt. % PEEK in Acrylate composite biomaterial can be processed using DLP 3D-printing at room temperature, and the resulting products are suitable for the fabrication of biomedical implants, prosthetic implants, tissue engineering scaffolds, and other healthcare applications. However, further research is needed to fully understand the behavior of these composite materials in realistic clinical conditions. – Future studies should focus on fatigue testing to evaluate the material’s durability under cyclic loading conditions that simulate the loads experienced by implants installed within the human body. – In addition, clinical trials are needed to confirm the biocompatibility and performance of this material over extended periods. References 1. Ahmad J.R., Aldo F.M., Ifran S., Tri K., Yudan W. The needs of current implant technology in orthopaedic prosthesis biomaterials application to reduce prosthesis failure rate. Journal of Nanomaterials, 2016, art. 5386924. DOI: 10.1155/2016/5386924. 2. Garcia E., Fernandez A., Martin L. Comparative analysis of traditional and advanced materials for hip joint implants. Materials Science and Engineering C, 2020, vol. 112, p. 110857. DOI: 10.1080/17453674.2018.1427320. 3. Verma S., Sharma N., Kango S., Sharma S. Developments of PEEK (Polyetheretherketone) as a biomedical material: a focused review. European Polymer Journal, 2021, vol. 147, p. 110295. DOI: 10.1016/j.eurpolymj.2021.110295. 4. Luo C., Liu Y., Peng B., Chen M., Liu Z., Li Z., Kuang H., Gong B., Li Z., Sun H. PEEK for oral applications: recent advances in mechanical and adhesive properties. Polymers, 2023, vol. 15 (2). DOI: 10.3390/ polym15020386. 5. Obinna O., Stachurek I., Kandasubramanian B., Njuguna J. 3D printing for hip implant applications: a review. Polymers, 2020, vol. 12 (11), p. 2682. DOI: 10.3390/polym12112682. 6. Dama Y., Jogi B., Pawade R., Kulkarni A. 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. 7. Xue Z., Wang Z., Sun A., Huang J., Wu W., Chen M., Hao X., Huang Z., Lin X., Wenig S. Rapid construction of polyetheretherketone (PEEK) biological implants incorporated with brushite (CaHPO4·2H2O) and antibiotics for anti-infection and enhanced osseointegration. Materials Science & Engineering: C, 2020, vol. 111, p. 110782. DOI: 10.1016/j.msec.2020.110782.
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