TY - JOUR AU - Csvila, Péter AU - Kovács, Zsófia AU - Toldy, Andrea AU - Czigány, Tibor TI - Zinc Oxide and Expandable Graphite-Based Flame Retardant Coatings of Unsaturated Polyester Resin for Composite Applications JF - JOURNAL OF VINYL AND ADDITIVE TECHNOLOGY J2 - J VINYL ADDIT TECHN VL - 32 PY - 2026 IS - 2 SP - 499 EP - 513 PG - 15 SN - 1083-5601 DO - 10.1002/vnl.70055 UR - https://m2.mtmt.hu/api/publication/36680612 ID - 36680612 N1 - Published online: 14 December 2025 Funding Agency and Grant Number: OTKA K 146236, OTKA K 138472 and OTKA K 142517 [TKP2021-NVA, TKP-6-6/PALY-2021, 2022-2.1.1-NL-2022-00012] Funding text: This work was supported by Nemzeti Kutatasi, Fejlesztesi es Innovacios Alap, OTKA K 146236, OTKA K 138472 and OTKA K 142517, TKP2021-NVA, TKP-6-6/PALY-2021, 2022-2.1.1-NL-2022-00012, Doctoral Excellence Fellowship Programme (DCEP). AB - Halogen-free multifunctional composite coatings modified with zinc oxide (ZnO) and expandable graphite (EG) on glass fiber–reinforced unsaturated polyester resin (UPR) composites, developed for applications in electronics and other areas where local heat loads and mechanical stress can affect the composite surface, were investigated. The primary objective of the coatings was to provide mechanical protection and enhanced flame retardancy without the use of halogen-based flame retardants. The combined use of ZnO and EG reduced the maximum average rate of heat emission by 64% compared to the reference (465 kW/m2). Furthermore, the effective heat of combustion was reduced from 3156 to 41 MJ/kg with the combined use of the flame retardants. In glow wire flammability index tests, the ignition temperature increased by 310°C compared to the uncoated composite. When ZnO and EG were used together, a stable, intumescent char layer formed that effectively protected the substrate under local heat stress. The additives did not influence the adhesion of the coatings, while the combined ZnO–EG system demonstrated higher toughness and better crack dispersion under bending loads, maintaining coating integrity even after local deformation. These results indicate that halogen-free ZnO–EG coatings can provide both flame retardancy and mechanical robustness, making them promising for structural and electrical composite components exposed to heat and mechanical stress. LA - English DB - MTMT ER - TY - JOUR AU - Csvila, Péter AU - Kovács, Zsófia AU - Toldy, Andrea AU - Czigány, Tibor TI - The synergistic effect of expandable graphite and zinc oxide as flame retardants on the properties of epoxy resin JF - JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY J2 - J THERM ANAL CALORIM VL - 151 PY - 2026 SP - 2141 EP - 2156 PG - 16 SN - 1388-6150 DO - 10.1007/s10973-025-15196-3 UR - https://m2.mtmt.hu/api/publication/36892322 ID - 36892322 N1 - Published online: 13 January 2026 Funding Agency and Grant Number: Budapest University of Technology and Economics; Nemzeti Kutatsi, Fejlesztsi s Innovacis Alap [OTKA K 146236, OTKA K 138472, OTKA K 142517, TKP-6-6/PALY-2021, TKP2021-NVA, 2022-2.1.1-NL-2022-00012, Doctoral Excellence Fellowship Programme (DCEP)] Funding text: Open access funding provided by Budapest University of Technology and Economics. AB - In this study, zinc oxide (ZnO) nanoparticles and expandable graphite (EG) were used as flame retardants to reduce the flammability of epoxy resin. The flame retardants increased the flexural modulus of the epoxy matrix by up to 50%. The effective heat of combustion of the samples containing both ZnO and EG was reduced to more than one-third of the reference value, while the maximum average rate of heat emission of the samples showed a reduction of almost 60% compared to pure epoxy. During the burning of the epoxy resin, ZnO and EG reduced the emission of gas-phase compounds containing C-H and N-H bonds. The incorporation of ZnO into the epoxy matrix resulted in a "puff pastry-like" structure that facilitated the release of evolved gases during combustion, thereby promoting foaming in the intumescent char formation process. Moreover, ZnO contributed to the enhanced structural stability of the EG residue. LA - English DB - MTMT ER - TY - JOUR AU - Szederkényi, Bence AU - Kovács, Norbert Krisztián AU - Czigány, Tibor TI - A comprehensive review of fiber-reinforced topology optimization for advanced polymer composites produced by automated manufacturing JF - ADVANCED INDUSTRIAL AND ENGINEERING POLYMER RESEARCH J2 - ADV INDUST ENGIN POLYMER RES VL - 8 PY - 2025 IS - 1 SP - 113 EP - 131 PG - 19 SN - 2542-5048 DO - 10.1016/j.aiepr.2024.05.002 UR - https://m2.mtmt.hu/api/publication/34968038 ID - 34968038 AB - This review paper focuses on Fiber-Reinforced Topology Optimization (FRTO) methods for automated manufacturing techniques, addressing topology and morphology optimization. Accordingly, the review introduces the main TO techniques and the common reinforcement path design strategies using concurrent and sequential optimization approaches. Furthermore, this paper examines the potential transformation of the conventional role of TO algorithms in structural optimization by integrating Artificial Intelligence (AI) into the optimization process [1]. We collected and categorized the most relevant papers from the past decade in the field of FRTO; comparisons were made based on appropriate metrics, including algorithm types, effectiveness, and validation environment. We emphasize practical considerations such as manufacturing constraints and algorithmic efficiency, addressing real-world usability aspects [2]. The analysis underscores the necessity for universally applicable benchmark methods and standardization to facilitate direct comparisons among various methodologies [3]. The main conclusions of the paper highlight the emerging trends in research, the potential of fiber-reinforced polymer composites designed by FRTO, the challenges facing the field, and the efficiency improvements and synergy with AI, indicating an evolving role for TO in structural optimization. LA - English DB - MTMT ER - TY - JOUR AU - Kovács, József Gábor AU - Czigány, Tibor TI - The temptation of golden lies: Does Artificial Intelligence elevate or erode science? JF - EXPRESS POLYMER LETTERS J2 - EXPRESS POLYM LETT VL - 19 PY - 2025 IS - 3 SP - 230 EP - 232 PG - 3 SN - 1788-618X DO - 10.3144/expresspolymlett.2025.17 UR - https://m2.mtmt.hu/api/publication/35743506 ID - 35743506 N1 - Department of Polymer Engineering, Faculty of Mechanical Engineering, Budapest University of Technology and Economics, Műegyetem rkp. 3, Budapest, H-1111, Hungary MTA-BME Lendület Lightweight Polymer Composites Research Group, Műegyetem rkp. 3., Műegyetem rkp. 3, Budapest, H-1111, Hungary HUN-REN-BME Research Group for Composite Science and Technology, Műegyetem rkp. 3, Budapest, H-1111, Hungary Export Date: 14 February 2025; Cited By: 0; Correspondence Address: T. Czigány; Department of Polymer Engineering, Faculty of Mechanical Engineering, Budapest University of Technology and Economics, Budapest, Műegyetem rkp. 3, H-1111, Hungary; email: czigany@eik.bme.hu LA - English DB - MTMT ER - TY - JOUR AU - Szederkényi, Bence AU - Kovács, Norbert Krisztián AU - Czigány, Tibor TI - Improving energy absorption in cellular 3D-Printed fiber–reinforced structures with radially reinforced composite shells JF - COMPOSITES PART B-ENGINEERING J2 - COMPOS PART B-ENG VL - 301 PY - 2025 PG - 11 SN - 1359-8368 DO - 10.1016/j.compositesb.2025.112513 UR - https://m2.mtmt.hu/api/publication/36099973 ID - 36099973 N1 - The research reported in this paper was supported by the National Research, Development, and Innovation Office (NRDI, Hungary) through grants OTKA K 146236 and OTKA K 138472. The authors acknowledge the Ministry of Culture and Innovation of Hungary for support from the National Research, Development and Innovation Fund through grant no. NKKP ADVANCED 149578. Project no. TKP-6-6/PALY-2021 has been implemented with the support provided by the Ministry of Culture and Innovation of Hungary from the National Research, Development and Innovation Fund, financed under the TKP2021-NVA funding scheme. The project 2022–2.1.1-NL-2022-00012 has been implemented with the support provided by the Ministry of Culture and Innovation of Hungary from the National Research, Development and Innovation Fund, financed under the 2022–2.1.1-NL Creation of National Laboratories, Complex Development funding scheme. Bence Szederkényi expresses appreciation for the support of the Doctoral Excellence Fellowship Programme (DCEP) and of the University Research Fellowship Programme (EKÖP) funded by the National Research Development and Innovation Fund of the Ministry of Culture and Innovation and the Budapest University of Technology and Economics, under a grant agreement with the National Research, Development and Innovation Office. Norbert Krisztián Kovács expresses appreciation for the support of the János Bolyai Research Scholarship of the Hungarian Academy of Sciences. AB - This study investigates the energy absorption capabilities of cellular structures combined with carbon fiber–reinforced polymer shells. The cellular core was produced by material extrusion 3D printing, while the shells were manufactured by the hand layup of carbon fiber-epoxy prepreg. Various material and reinforcement configurations were analyzed in a combined configuration and separately on a component level. The energy absorption properties of the printed specimens were evaluated after quasi-dynamic compression tests, demonstrating that the introduced radially reinforced hoop layers significantly improved compressive load-bearing capacity by resisting delamination and, consequently, local buckling in the 3D-printed cellular structures. This led to stable failure modes and higher specific energy absorption (SEA). The hybrid structures, which combined external shells with a cellular framework, exhibited a synergistic effect, resulting in up to a 200 % improvement in SEA. © 2025 LA - English DB - MTMT ER - TY - JOUR AU - Magyar, Balázs AU - Czigány, Tibor AU - Török, Dániel AU - Marton, Gergő Zsolt AU - Balogh, Fanni AU - Szebényi, Gábor TI - Modeling of the Healing Process of Polycaprolactone-Interleaved Carbon Fiber–Reinforced Composites JF - POLYMER COMPOSITES J2 - POLYM COMPOSITE VL - 46 PY - 2025 IS - 15 SP - 14422 EP - 14432 PG - 11 SN - 0272-8397 DO - 10.1002/pc.30070 UR - https://m2.mtmt.hu/api/publication/36123320 ID - 36123320 N1 - We would like to sincerely thank the late Prof. Dr. h.c. mult. József Karger-Kocsis for his support and valuable comments, which serve as a solid foundation of our research. The research has been supported by the NRDI Office (OTKA FK 142540). Gábor Szebényi acknowledges the financial support received through the János Bolyai Scholarship of the Hungarian Academy of Sciences and ÚNKP-23-5-BME-415 New National Excellence Program. Project no. 2022-2.1.1-NL-2022-00012 National Laboratory for Cooperative Technologies has been implemented with the support provided by the Ministry of Culture and Innovation of Hungary from the National Research, Development, and Innovation Fund, financed under the National Laboratories funding scheme. Project no. TKP-6-6/PALY-2021 has been implemented with the support provided by the Ministry of Culture and Innovation of Hungary from the National Research, Development and Innovation Fund, financed under the TKP2021-NVA funding scheme. Project no. KDP-IKT-2023-900-I1-00000957/0000003 has been implemented with the support provided by the Ministry of Culture and Innovation of Hungary from the National Research, Development and Innovation Fund, financed under the KDP-2023 funding scheme. The project supported by the Doctoral Excellence Fellowship Programme (DCEP) is funded by the National Research Development and Innovation Fund of the Ministry of Culture and Innovation and the Budapest University of Technology and Economics. AB - Thermoplastic interlayer provides an excellent opportunity to heal/repair inhomogeneities or damage in composites. By melting the thermoplastic interlayer, the damage can be filled, thereby increasing the service life of the composite part. In this paper, we analyzed the healing process of carbon fiber–reinforced epoxy matrix composites with a thermoplastic, structured interlayer (created by FFF 3D printing method) during ENF tests. We observed the effect of the concentration of the interlayer and the applied surface pressure on the properties of the healing process. The results show that increasing interlayer content can improve maximal healing efficiency from 96.6% ± 0.3% (25 A/A%) to 98.8% ± 0.3% (100 A/A%). While healing pressure does not affect the healing efficiency significantly, it can reduce the optimal healing time. In all cases, healing efficiency has an optimum, after which increased healing time leads to a decrease. To gain a deeper understanding of the process, we have adapted a control theory model, which helps in the selection of optimal process parameters for healing, which can be utilized for other thermoplastic interlayer-based healing methods. LA - English DB - MTMT ER - TY - JOUR AU - Vas, László Mihály AU - Czigány, Tibor AU - Tamás-Bényei, Péter TI - Development of a New Method for Characterize Resistance to Cyclic Tensile Load in Mono and Hybrid Composites JF - PERIODICA POLYTECHNICA-MECHANICAL ENGINEERING J2 - PERIOD POLYTECH MECH ENG VL - 69 PY - 2025 IS - 2 SP - 93 EP - 102 PG - 10 SN - 0324-6051 DO - 10.3311/PPme.37831 UR - https://m2.mtmt.hu/api/publication/36170061 ID - 36170061 N1 - Funding Agency and Grant Number: Ministry of Innovation and Technology of Hungary from the National Research, Development and Innovation Fund [BME-NVA-02]; New National Excellence Program of The Ministry for Culture and Innovation from the source of the National Research, Development and Innovation Fund [UNKP-23-5-BME-309]; Janos Bolyai Research Scholarship of the Hungarian Academy of Sciences [BO/00658/21/6] Funding text: The research reported in this paper is part of project no. BME-NVA-02, implemented with the support provided by the Ministry of Innovation and Technology of Hungary from the National Research, Development and Innovation Fund, financed under the TKP2021 funding scheme. This research was also supported by the UNKP-23-5-BME-309 New National Excellence Program of The Ministry for Culture and Innovation from the source of the National Research, Development and Innovation Fund. This project was supported by the Janos Bolyai Research Scholarship of the Hungarian Academy of Sciences (BO/00658/21/6) . AB - The objective of our study was to investigate and describe the durability of mono and hybrid composite materials reinforced with various fabrics (namely, glass, carbon, and basalt) and an epoxy resin matrix against repetitive loads, with a particular focus on their potential use in wind turbine blades. The mechanical properties of these materials were evaluated through repeated tensile tests involving high deflection and low cycle numbers. A new approach was introduced for characterizing and comparing the performance of glass, carbon, and basalt fiber reinforced epoxy composites. Our results led to the development of a novel model to evaluate a new mechanical property, the asymptotic modulus, which can be used to assess the resistance of composite materials to multi-cycle tensile loads in a faster and simpler manner. Differences between the measured and by our model predicted values were low, the values of determination coefficient were higher than 94%. LA - English DB - MTMT ER - TY - JOUR AU - Szederkényi, Bence AU - Czigány, Tibor TI - 3D nyomtatott polimer kompozit szerkezetek rétegközi mechanikai tulajdonságainak meghatározása JF - POLIMEREK J2 - POLIMEREK VL - 11 PY - 2025 IS - 7 SP - 218 EP - 224 PG - 7 SN - 2415-9492 UR - https://m2.mtmt.hu/api/publication/36172855 ID - 36172855 N1 - A Doktoranduszi Kiválósági Ösztöndíj Program (DKÖP) által támogatott kutatás a Kulturális és Innovációs Minisztérium Nemzeti Kutatási Fejlesztési és Innovációs Alapból nyújtott, valamint a Budapesti Műszaki és Gazdaságtudományi Egyetem közös támogatásával, a Nemzeti Kutatási, Fejlesztési és Innovációs Hivatallal kötött támogatási szerződés alapján valósult meg. Az Egyetemi Kutatói Ösztöndíj Program (EKÖP) által támogatott kutatást a Kulturális és Innovációs Minisztérium Nemzeti Kutatási Fejlesztési és Innovációs Alapból nyújtott, a Nemzeti Kutatási, Fejlesztési és Innovációs Alap támogatási szerződés alapján valósult meg. A kutatást a 2022-2.1.1-NL-2022-00012 – Kooperatív Technológiák Nemzeti Laboratórium pályázat támogatta. Az eredmények megjelenését a Nemzeti Kutatási és Innovációs Alap OTKA K 138472 számú pályázata támogatta. AB - A cikk ömledékextrúzióval gyártott, folytonos szálerősítésű kompozitok rétegközi tulajdonságait vizsgálja. A vizsgálatokhoz használt próbatestek Markforged Onyx (rövid szénszállal töltött PA12) alapanyagból és folytonos szénszálakkal erősített, PA12 mátrixanyaggal impregnált szálkötegekből 3D nyomtatással készültek. A célzott anyagjellemzéshez előállított egyedi szakító és nyíró próbatestek alkalmasak az egyes komponensek és a fázishatáron kialakuló kapcsolatok külön értékelésére. A mérések a nyomtatási síkkal párhuzamos és arra merőleges irányokban vizsgálták a rétegközi tulajdonságokat, lehetővé téve a rétegtapadás irányfüggő viselkedésének részletes leírását és a numerikus modellek ennek megfelelő kalibrálását. A szimulációs és mérési eredmények 5 százalékon belüli eltérést mutattak. | This paper investigates the interlayer properties of continuous fiber-reinforced composites manufactured with material extrusion-based 3D printing. Specimens were printed with a Markforged Onyx matrix material (PA12 reinforced with short carbon fibers) and continuous carbon fiber bundles impregnated with a PA12 matrix. Custom tensile and shear test specimens were designed for targeted material characterization, enabling the separate evaluation of the individual components and the adhesion behavior at the interfaces between phases. Measurements were conducted parallel and perpendicular to the printing plane to allow for a detailed description of the anisotropic nature of interlayer adhesion and the corresponding calibration of numerical models. The deviation between the simulation and the experimental results remained within five percent. LA - Hungarian DB - MTMT ER - TY - JOUR AU - Hou, Cong AU - Nemes-Károly, István AU - Pastrav, Leonard AU - Vrancken, Bey AU - Kocsis, György AU - Szebényi, Gábor AU - Czigány, Tibor AU - Denis, Kathleen TI - Friction and wear reduction effect of laser powder bed fusion produced Voronoi structures in lubricated metal-polymer sliding pairs JF - JOURNAL OF THE MECHANICAL BEHAVIOR OF BIOMEDICAL MATERIALS J2 - J MECH BEHAV BIOMED VL - 171 PY - 2025 PG - 15 SN - 1751-6161 DO - 10.1016/j.jmbbm.2025.107138 UR - https://m2.mtmt.hu/api/publication/36272567 ID - 36272567 N1 - This work is supported by the CELSA Research Fund, Belgium and by Internal Funds KU Leuven, Belgium. This research is supported by the NRDI Office (OTKA K 138472). Gábor Szebényi acknowledges the financial support received through the János Bolyai Scholarship of the Hungarian Academy of Sciences and ÚNKP-23-5-BME-415 New National Excellence Program. The authors are grateful to ir. Kopila Gurung for her assistance in producing the samples. AB - The failure of artificial joints is often attributed to wear, prompting researchers to explore effective solutions such as material improvement, surface texturing and coating. This study introduces a novel approach of employing 3D printed Voronoi structures to enhance lubrication in polymer-metal sliding wear, with the aim of extending the longevity of artificial joint systems. Specifically, this study investigates the relationship between the geometries and tribological properties of Ti6Al4V Voronoi structures, paired with ultra-high-molecular-weight polyethylene (UHMWPE). The results indicate that the void size in Voronoi structures can be manipulated to match the feature size in the surface texturing approach, suggesting the potential to induce the hydrodynamic effect for friction reduction. The effect of Voronoi structures on reducing friction and wear was examined using pin-on-disc (PoD) tests. In comparison to the control group of solid pins, implementing Voronoi structures in the pins decreases the mean values of static coefficient of friction (COF), dynamic COF, and wear volume by 24.6 %, 29.4 %, and 51.2 %, respectively. Indistinct trends were observed between the COF and the geometric parameters of Voronoi structures. It is hypothesised that interconnected porosity networks within Voronoi structures may preserve wear debris and retain lubricant, potentially elevating hydrodynamic pressure and thereby improving the friction condition. Moreover, comparative analysis of the wear tracks confirms the effective wear reduction achieved by Voronoi structures, with abrasion identified as the primary wear mechanism. LA - English DB - MTMT ER - TY - JOUR AU - Magyar, Balázs AU - Czigány, Tibor AU - Marton, Gergő Zsolt AU - Balogh, Fanni AU - Szebényi, Gábor TI - Designable phase structure in semi-interpenetrating polymer network (semi-IPN) materials: an idea to alter interfacial adhesion along the fibre in polymer composites JF - POLYMER J2 - POLYMER VL - 337 PY - 2025 PG - 12 SN - 0032-3861 DO - 10.1016/j.polymer.2025.128998 UR - https://m2.mtmt.hu/api/publication/36326546 ID - 36326546 N1 - Received 13 June 2025, Revised 7 August 2025, Accepted 29 August 2025, Available online 29 August 2025, Version of Record 5 September 2025. The research has been supported by the NRDI Office (OTKA FK 142540). Gábor Szebényi acknowledges the financial support received through the János Bolyai Scholarship of the Hungarian Academy of Sciences and ÚNKP-23-5-BME-415 New National Excellence Program. Project no. 2022–2.1.1-NL-2022-00012 National Laboratory for Cooperative Technologies has been implemented with the support provided by the Ministry of Culture and Innovation of Hungary from the National Research, Development, and Innovation Fund, financed under the National Laboratories funding scheme. Project no. TKP-6-6/PALY-2021 has been implemented with the support provided by the Ministry of Culture and Innovation of Hungary from the National Research, Development and Innovation Fund, financed under theTKP2021-NVA funding scheme. Project no. KDP-IKT-2023-900-I1-00000957/0000003 has been implemented with the support provided by the Ministry of Culture and Innovation of Hungary from the National Research, Development and Innovation Fund, financed under the KDP-2023 funding scheme. The project supported by the Doctoral Excellence Fellowship Programme (DCEP) is funded by the National Research Development and Innovation Fund of the Ministry of Culture and Innovation and the Budapest University of Technology and Economics. AB - The pseudo-ductile behaviour of carbon fibre-reinforced polymer composites can be enhanced through the integration of thermoplastic phases into the thermoset matrix. This study investigates the formation and control of phase morphology in epoxy resin modified with poly(ɛ-caprolactone) (PCL), targeting the development of a semi-interpenetrating polymer network (semi-IPN) structure. Phase morphology and thermal transitions were analysed using differential scanning calorimetry (DSC), atomic force microscopy (AFM), and scanning electron microscopy (SEM). The interfacial shear strength between the matrix and reinforcing fibres was evaluated through microdroplet testing. Furthermore, a novel strategy was introduced using 3D printing to locally modulate phase structure along the fibre length, offering spatial control over fibre–matrix interactions. The results demonstrate the feasibility of tuning composite interphases to improve toughness and interfacial behaviour in advanced structural materials. LA - English DB - MTMT ER -