@article{MTMT:36680612, title = {Zinc Oxide and Expandable Graphite-Based Flame Retardant Coatings of Unsaturated Polyester Resin for Composite Applications}, url = {https://m2.mtmt.hu/api/publication/36680612}, author = {Csvila, Péter and Kovács, Zsófia and Toldy, Andrea and Czigány, Tibor}, doi = {10.1002/vnl.70055}, journal-iso = {J VINYL ADDIT TECHN}, journal = {JOURNAL OF VINYL AND ADDITIVE TECHNOLOGY}, volume = {32}, unique-id = {36680612}, issn = {1083-5601}, abstract = {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.}, keywords = {COATING; Glass fiber; unsaturated polyester resin; Flame retardant system}, year = {2026}, eissn = {1548-0585}, pages = {499-513}, orcid-numbers = {Toldy, Andrea/0000-0003-3569-1828; Czigány, Tibor/0000-0002-5138-0141} } @article{MTMT:36892322, title = {The synergistic effect of expandable graphite and zinc oxide as flame retardants on the properties of epoxy resin}, url = {https://m2.mtmt.hu/api/publication/36892322}, author = {Csvila, Péter and Kovács, Zsófia and Toldy, Andrea and Czigány, Tibor}, doi = {10.1007/s10973-025-15196-3}, journal-iso = {J THERM ANAL CALORIM}, journal = {JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY}, volume = {151}, unique-id = {36892322}, issn = {1388-6150}, abstract = {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.}, keywords = {CARBON NANOTUBES; THERMODYNAMICS; flame retardancy; Zinc oxide; epoxy resin; Chemistry, Analytical; Expandable graphite}, year = {2026}, eissn = {1588-2926}, pages = {2141-2156}, orcid-numbers = {Toldy, Andrea/0000-0003-3569-1828; Czigány, Tibor/0000-0002-5138-0141} } @article{MTMT:34968038, title = {A comprehensive review of fiber-reinforced topology optimization for advanced polymer composites produced by automated manufacturing}, url = {https://m2.mtmt.hu/api/publication/34968038}, author = {Szederkényi, Bence and Kovács, Norbert Krisztián and Czigány, Tibor}, doi = {10.1016/j.aiepr.2024.05.002}, journal-iso = {ADV INDUST ENGIN POLYMER RES}, journal = {ADVANCED INDUSTRIAL AND ENGINEERING POLYMER RESEARCH}, volume = {8}, unique-id = {34968038}, issn = {2542-5048}, abstract = {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.}, keywords = {Artificial intelligence; finite element analysis; Topology optimization; Concurrent optimization; Automated Manufacturing; Reinforcement optimization}, year = {2025}, eissn = {2542-5048}, pages = {113-131}, orcid-numbers = {Czigány, Tibor/0000-0002-5138-0141} } @article{MTMT:35743506, title = {The temptation of golden lies: Does Artificial Intelligence elevate or erode science?}, url = {https://m2.mtmt.hu/api/publication/35743506}, author = {Kovács, József Gábor and Czigány, Tibor}, doi = {10.3144/expresspolymlett.2025.17}, journal-iso = {EXPRESS POLYM LETT}, journal = {EXPRESS POLYMER LETTERS}, volume = {19}, unique-id = {35743506}, issn = {1788-618X}, year = {2025}, eissn = {1788-618X}, pages = {230-232}, orcid-numbers = {Kovács, József Gábor/0000-0002-7391-7085; Czigány, Tibor/0000-0002-5138-0141} } @article{MTMT:36099973, title = {Improving energy absorption in cellular 3D-Printed fiber–reinforced structures with radially reinforced composite shells}, url = {https://m2.mtmt.hu/api/publication/36099973}, author = {Szederkényi, Bence and Kovács, Norbert Krisztián and Czigány, Tibor}, doi = {10.1016/j.compositesb.2025.112513}, journal-iso = {COMPOS PART B-ENG}, journal = {COMPOSITES PART B-ENGINEERING}, volume = {301}, unique-id = {36099973}, issn = {1359-8368}, abstract = {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}, keywords = {ENERGY; Shells (structures); Local buckling; Compression testing; Energy absorption; Carbon fiber reinforced plastics; CELLULAR STRUCTURES; Cellulars; cellular structure; Reinforced composites; specific energy absorption; specific energy absorption; triply periodic minimal surfaces; triply periodic minimal surfaces; Carbon fibre reinforced polymer; 3D printed carbon fiber–reinforced polymer; Shell reinforcement; 3d printed carbon fiber–reinforced polymer; Fibre reinforced structures; Shell reinforcement}, year = {2025}, eissn = {1879-1069}, orcid-numbers = {Czigány, Tibor/0000-0002-5138-0141} } @article{MTMT:36123320, title = {Modeling of the Healing Process of Polycaprolactone-Interleaved Carbon Fiber–Reinforced Composites}, url = {https://m2.mtmt.hu/api/publication/36123320}, author = {Magyar, Balázs and Czigány, Tibor and Török, Dániel and Marton, Gergő Zsolt and Balogh, Fanni and Szebényi, Gábor}, doi = {10.1002/pc.30070}, journal-iso = {POLYM COMPOSITE}, journal = {POLYMER COMPOSITES}, volume = {46}, unique-id = {36123320}, issn = {0272-8397}, abstract = {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.}, year = {2025}, eissn = {1548-0569}, pages = {14422-14432}, orcid-numbers = {Magyar, Balázs/0000-0003-0665-8965; Czigány, Tibor/0000-0002-5138-0141; Török, Dániel/0000-0003-4521-2771; Szebényi, Gábor/0000-0003-3174-0661} } @article{MTMT:36170061, title = {Development of a New Method for Characterize Resistance to Cyclic Tensile Load in Mono and Hybrid Composites}, url = {https://m2.mtmt.hu/api/publication/36170061}, author = {Vas, László Mihály and Czigány, Tibor and Tamás-Bényei, Péter}, doi = {10.3311/PPme.37831}, journal-iso = {PERIOD POLYTECH MECH ENG}, journal = {PERIODICA POLYTECHNICA-MECHANICAL ENGINEERING}, volume = {69}, unique-id = {36170061}, issn = {0324-6051}, abstract = {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%.}, year = {2025}, eissn = {1587-379X}, pages = {93-102}, orcid-numbers = {Czigány, Tibor/0000-0002-5138-0141; Tamás-Bényei, Péter/0000-0002-0001-3544} } @article{MTMT:36172855, title = {3D nyomtatott polimer kompozit szerkezetek rétegközi mechanikai tulajdonságainak meghatározása}, url = {https://m2.mtmt.hu/api/publication/36172855}, author = {Szederkényi, Bence and Czigány, Tibor}, journal-iso = {POLIMEREK}, journal = {POLIMEREK}, volume = {11}, unique-id = {36172855}, issn = {2415-9492}, abstract = {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.}, year = {2025}, pages = {218-224}, orcid-numbers = {Czigány, Tibor/0000-0002-5138-0141} } @article{MTMT:36272567, title = {Friction and wear reduction effect of laser powder bed fusion produced Voronoi structures in lubricated metal-polymer sliding pairs}, url = {https://m2.mtmt.hu/api/publication/36272567}, author = {Hou, Cong and Nemes-Károly, István and Pastrav, Leonard and Vrancken, Bey and Kocsis, György and Szebényi, Gábor and Czigány, Tibor and Denis, Kathleen}, doi = {10.1016/j.jmbbm.2025.107138}, journal-iso = {J MECH BEHAV BIOMED}, journal = {JOURNAL OF THE MECHANICAL BEHAVIOR OF BIOMEDICAL MATERIALS}, volume = {171}, unique-id = {36272567}, issn = {1751-6161}, abstract = {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.}, year = {2025}, eissn = {1878-0180}, orcid-numbers = {Hou, Cong/0000-0003-2656-0885; Pastrav, Leonard/0000-0003-1843-7916; Vrancken, Bey/0000-0001-6266-9816; Szebényi, Gábor/0000-0003-3174-0661; Czigány, Tibor/0000-0002-5138-0141} } @article{MTMT:36326546, title = {Designable phase structure in semi-interpenetrating polymer network (semi-IPN) materials: an idea to alter interfacial adhesion along the fibre in polymer composites}, url = {https://m2.mtmt.hu/api/publication/36326546}, author = {Magyar, Balázs and Czigány, Tibor and Marton, Gergő Zsolt and Balogh, Fanni and Szebényi, Gábor}, doi = {10.1016/j.polymer.2025.128998}, journal-iso = {POLYMER}, journal = {POLYMER}, volume = {337}, unique-id = {36326546}, issn = {0032-3861}, abstract = {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.}, year = {2025}, eissn = {1873-2291}, orcid-numbers = {Magyar, Balázs/0000-0003-0665-8965; Czigány, Tibor/0000-0002-5138-0141; Szebényi, Gábor/0000-0003-3174-0661} }