{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,12]],"date-time":"2026-09-12T16:50:38Z","timestamp":1789231838427,"version":"build-2803163510"},"reference-count":52,"publisher":"MDPI AG","issue":"6","license":[{"start":{"date-parts":[[2026,3,10]],"date-time":"2026-03-10T00:00:00Z","timestamp":1773100800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Polymers"],"abstract":"<jats:p>Fused deposition modeling\/fused filament fabrication (FDM\/FFF) enables architectural tailoring of mechanical response through layer configuration and multi-material manufacturing strategies. However, the combined effects of layer arrangement, infill ratio, and packing geometry in polymer\u2013metal hybrid structures and interfacial load transfer mechanisms are still not sufficiently elucidated. In this study, the tensile behavior of single- and multi-material structures produced using PLA and 17-4 PH stainless steel filaments was systematically investigated. A total of 24 experimental parameter sets were created with four-layer configurations (PLA, 17-4 PH, PLA\/17-4 PH\/PLA, and 17-4 PH\/PLA\/17-4 PH), three infill ratios (20%, 60%, and 100%), and two packing patterns (linear and hexagonal); the samples were tested according to the ASTM D638 standard. Mechanical data were modeled using Response Surface Methodology (RSM) and ANOVA, and the developed regression models showed high accuracy (R2 &gt; 0.95). The findings showed that tensile and yield strength are primarily controlled by the layer arrangement, while infill ratio and infill pattern have a secondary effect. The highest strength was measured in 100% infill linear PLA samples (\u224810.35 MPa), and the lowest value was measured in 17-4 PH \u201cgreen part\u201d samples without sintering (\u22480.92 MPa). Hybrid structures exhibited intermediate performance in the range of 2.9\u20134.9 MPa. ANOVA results showed that the majority of the mechanical variance was explained by the layer arrangement (70\u201385% contribution), while infill ratio and infill pattern had a secondary effect. Fracture surface analyses showed that high performance was associated with homogeneous filament fusion and low porosity; Studies have confirmed that poor performance is associated with delamination and interfacial separation.<\/jats:p>","DOI":"10.3390\/polym18060672","type":"journal-article","created":{"date-parts":[[2026,3,10]],"date-time":"2026-03-10T14:45:39Z","timestamp":1773153939000},"page":"672","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":3,"title":["Reinforcement of Novel PLA\/17-4 PH Stainless Steel Hybrid Structures Fabricated by FDM: The Effects of Layer Configuration, Infill Density and Pattern"],"prefix":"10.3390","volume":"18","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-7125-6981","authenticated-orcid":false,"given":"Ramazan","family":"\u00d6t\u00fcken","sequence":"first","affiliation":[{"name":"Department of Electronic Automation, Vocational School of Technical Sciences, Recep Tayyip Erdo\u011fan University, Rize 53100, T\u00fcrkiye"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7316-360X","authenticated-orcid":false,"given":"Cem","family":"Alparslan","sequence":"additional","affiliation":[{"name":"Department of Mechanical Engineering, Faculty of Engineering and Architecture, Recep Tayyip Erdogan University, Rize 53100, T\u00fcrkiye"},{"name":"FDM and Metallography Laboratory, Department of Mechanical Engineering, Recep Tayyip Erdogan University, Rize 53100, T\u00fcrkiye"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4684-7939","authenticated-orcid":false,"given":"Muhammed Furkan","family":"Erhan","sequence":"additional","affiliation":[{"name":"Department of Manufacturing Engineering, Faculty of Technology, Gazi University, Ankara 06560, T\u00fcrkiye"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8226-0188","authenticated-orcid":false,"given":"\u015eenol","family":"Bayraktar","sequence":"additional","affiliation":[{"name":"Department of Mechanical Engineering, Faculty of Engineering and Architecture, Recep Tayyip Erdogan University, Rize 53100, T\u00fcrkiye"},{"name":"FDM and Metallography Laboratory, Department of Mechanical Engineering, Recep Tayyip Erdogan University, Rize 53100, T\u00fcrkiye"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,3,10]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Kirchheim, A., Dennig, H.J., and Zumofen, L. (2017, January 13\u201315). Why Education and Training in the Field of Additive Manufacturing Is a Necessity: The Right Way to Teach Students and Professionals. Proceedings of the Industrializing Additive Manufacturing\u2014Proceedings of Additive Manufacturing in Products and Applications\u2014AMPA2017, Zurich, Switzerland.","DOI":"10.1007\/978-3-319-66866-6_31"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"22","DOI":"10.1016\/j.mattod.2017.07.001","article-title":"Additive Manufacturing: Scientific and Technological Challenges, Market Uptake and Opportunities","volume":"21","author":"Tofail","year":"2018","journal-title":"Mater. Today"},{"key":"ref_3","first-page":"1699","article-title":"Mechanical and Metrological Characterisation of 17-4 PH Stainless Steel Structures Processed by Material Extrusion Additive Manufacturing","volume":"38","author":"Caminero","year":"2024","journal-title":"J. Mater. Res. Technol."},{"key":"ref_4","doi-asserted-by":"crossref","unstructured":"Alparslan, C., and Bayraktar, \u015e. (2025). Advances in Digital Light Processing (DLP) Bioprinting: A Review of Biomaterials and Its Applications, Innovations, Challenges, and Future Perspectives. Polymers, 17.","DOI":"10.3390\/polym17091287"},{"key":"ref_5","doi-asserted-by":"crossref","unstructured":"Bayraktar, \u015e., and Alparslan, C. (2023). Comparison of the SLM, SLS, and DLMS Techniques in Additive Manufacture of AlSi10Mg Alloys. Innovation and Sustainable Manufacturing, Woodhead Publishing.","DOI":"10.1016\/B978-0-12-819513-0.00004-4"},{"key":"ref_6","doi-asserted-by":"crossref","unstructured":"Alparslan, C., and Bayraktar, \u015e. (2025). Challenges and Innovations in 3D Printed Biomaterials and Biomedical Applications. Challenges and Innovations in 3D Printed Bio-Organs and Their Materials. Springer Tracts in Additive Manufacturing, Springer.","DOI":"10.1007\/978-3-031-90807-1_2"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"18024","DOI":"10.1007\/s11665-024-10445-2","article-title":"Microstructural, Mechanical, and Electrochemical Corrosion Properties of Extrusion Additive Manufactured 17-4 Precipitation Hardenable Stainless Steel","volume":"34","author":"Liew","year":"2025","journal-title":"J. Mater. Eng. Perform."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1007\/s00170-023-12189-0","article-title":"3D Printing of High Melting Iron Alloys Using Metal-Fused Deposition Modeling: A Comprehensive Review","volume":"129","author":"Drummond","year":"2023","journal-title":"Int. J. Adv. Manuf. Technol."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"2911","DOI":"10.1007\/s00170-023-11646-0","article-title":"An Empirical Method for Forecasting Energy Consumption in Material Extrusion","volume":"127","author":"Quarto","year":"2023","journal-title":"Int. J. Adv. Manuf. Technol."},{"key":"ref_10","unstructured":"Song, J. (2007). Experiments, Modelling and Numerical Simulation of the Sintering Process for Metallic or Ceramic Powders. [Ph.D. Thesis, University of Besan\u00e7on]."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"108241","DOI":"10.1016\/j.polymertesting.2023.108241","article-title":"Lapping Optimization of Additively Manufactured ABS\u2013Carbon Fiber Composite Parts Using the Soft Computing Technique","volume":"128","author":"Taghizadeh","year":"2023","journal-title":"Polym. Test."},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Ahmad, N.F.N. (2026, March 04). Effect of Debinding Method and Sintering Atmosphere on Fused Filament Fabrication Printed 17-4 PH Stainless Steel at Intermediate Sintering Temperatures. Available online: https:\/\/sciety.org\/articles\/activity\/10.21203\/rs.3.rs-7828599\/v1?utm_source=sciety_labs_article_page.","DOI":"10.21203\/rs.3.rs-7828599\/v1"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"115539","DOI":"10.1016\/j.matchar.2025.115539","article-title":"Process\u2013Structure\u2013Property Relationships of Binder Jetted 17\u20134PH Stainless Steel","volume":"229","author":"Khademitab","year":"2025","journal-title":"Mater. Charact."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"342","DOI":"10.3365\/KJMM.2018.56.5.342","article-title":"Microstructure and Mechanical Properties of 17-4 PH Steel and Fe\u2013Cr\u2013B Alloy Mixed Material Manufactured Using Powder Injection Molding","volume":"56","author":"Joo","year":"2018","journal-title":"J. Korean Inst. Met. Mater."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"310","DOI":"10.1557\/s43579-021-00040-0","article-title":"The Effect of Varying Specimens\u2019 Printing Angles to the Bed Surface on the Tensile Strength of 3D-Printed 17-4 PH Stainless Steels via Metal FFF Additive Manufacturing","volume":"11","author":"Alkindi","year":"2021","journal-title":"MRS Commun."},{"key":"ref_16","first-page":"102117","article-title":"Investigation of Mechanical and Wear Properties of 17\u20134PH Materials Produced with Different Patterns in Atomic Diffusion Additive Manufacturing Technology","volume":"69","author":"Tasci","year":"2025","journal-title":"Eng. Sci. Technol. Int. J."},{"key":"ref_17","first-page":"746","article-title":"Thermal Fluctuations on the Corrosion Behaviour of 17-4 PH Stainless Steel Alloys Fabricated via Material Extrusion Additive Manufacturing Technique","volume":"239","author":"Mwema","year":"2025","journal-title":"Proc. Inst. Mech. Eng. Part L J. Mater. Des. Appl."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"051010","DOI":"10.1115\/1.4067615","article-title":"Determining the Parameters of Gurson\u2013Tvergaard\u2013Needleman Model for Predicting the Failure of Wrought and Fused Filament Fabricated 17-4 PH Stainless Steel","volume":"147","author":"Porrang","year":"2025","journal-title":"J. Manuf. Sci. Eng."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"7759","DOI":"10.1007\/s40964-025-01069-6","article-title":"Modeling the Effect of Microstructural Porosity on the Material Behavior of Fused Filament Fabricated 17-4 PH Stainless Steel","volume":"10","author":"Porrang","year":"2025","journal-title":"Prog. Addit. Manuf."},{"key":"ref_20","unstructured":"eSUN3D (2026, March 04). eSun3D T\u00fcrkiye Official Website. Available online: https:\/\/www.esun3d.com\/tr."},{"key":"ref_21","unstructured":"Prusa Research (2026, March 04). Filament. Available online: https:\/\/www.prusa3d.com\/category\/filament\/."},{"key":"ref_22","unstructured":"FlashForge (2026, February 09). Creator 3 Independent Dual Extruder (IDEX) 3D Printer. Available online: https:\/\/www.flashforge.com\/product-detail\/40."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"294","DOI":"10.1016\/j.polymertesting.2018.04.029","article-title":"Anisotropic Mechanical Property Variance between ASTM D638-14 Type I and Type IV Fused Filament Fabricated Specimens","volume":"68","author":"Laureto","year":"2018","journal-title":"Polym. Test."},{"key":"ref_24","doi-asserted-by":"crossref","unstructured":"Anand Kumar, S., and Shivraj Narayan, Y. (2019). Tensile Testing and Evaluation of 3D-Printed PLA Specimens as per ASTM D638 Type IV Standard. Innovative Design, Analysis and Development Practices in Aerospace and Automotive Engineering (I-DAD 2018), Springer.","DOI":"10.1007\/978-981-13-2718-6_9"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"178013","DOI":"10.1016\/j.jallcom.2024.178013","article-title":"Machinability Characteristics in Zn-40Al Alloy: The Effect of Addition of Copper and Silicon and Optimization of Cutting Parameters Using Response Surface Methodology","volume":"1010","author":"Bayraktar","year":"2025","journal-title":"J. Alloys Compd."},{"key":"ref_26","doi-asserted-by":"crossref","unstructured":"O\u011fuzt\u00fcrk, T., Alparslan, C., Sipahi, M., O\u011fuzt\u00fcrk, G.E., Topalo\u011flu, E.N., Bayraktar, \u015e., and Y\u00fcksek, T. (2026). Modeling the Effect of Cold Stratification on Seed Germination Performance of Rudbeckia fulgida Aiton Using Response Surface Methodology (RSM). Plants, 15.","DOI":"10.3390\/plants15020220"},{"key":"ref_27","first-page":"61","article-title":"Effects of Material, Infill Pattern and Infill Density on the Tensile Strength of Products Produced by Fused Filament Fabrication Method","volume":"5","year":"2024","journal-title":"J. Adv. Manuf. Eng."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"100","DOI":"10.1016\/j.matpr.2022.02.310","article-title":"Effect of Infill Pattern and Infill Density on Mechanical Behaviour of FDM 3D Printed Parts\u2014A Current Review","volume":"62","author":"Tanveer","year":"2022","journal-title":"Mater. Today Proc."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"143","DOI":"10.1016\/j.matdes.2017.03.065","article-title":"Additive Manufacturing of PLA Structures Using Fused Deposition Modelling: Effect of Process Parameters on Mechanical Properties and Their Optimal Selection","volume":"124","author":"Caminero","year":"2017","journal-title":"Mater. Des."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"183","DOI":"10.1089\/3dp.2015.0036","article-title":"Effect of Infill Parameters on Tensile Mechanical Behavior in Desktop 3D Printing","volume":"3","author":"Calle","year":"2016","journal-title":"3D Print. Addit. Manuf."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"012071","DOI":"10.1088\/1757-899X\/1038\/1\/012071","article-title":"Different Infill Geometry Influence on Mechanical Properties of FDM Produced PLA","volume":"1038","author":"Bergonzi","year":"2021","journal-title":"IOP Conf. Ser. Mater. Sci. Eng."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"110915","DOI":"10.1016\/j.compositesb.2023.110915","article-title":"Filament Fabrication and Subsequent Additive Manufacturing, Debinding, and Sintering for Extrusion-Based Metal Additive Manufacturing and Their Applications: A Review","volume":"264","author":"Bankapalli","year":"2023","journal-title":"Compos. Part B Eng."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"1097","DOI":"10.1108\/RPJ-05-2022-0169","article-title":"Material Extrusion Additive Manufacturing of 17\u20134PH Stainless Steel: Effect of Process Parameters on Mechanical Properties","volume":"29","author":"Basak","year":"2023","journal-title":"Rapid Prototyp. J."},{"key":"ref_34","doi-asserted-by":"crossref","unstructured":"Abe, Y., Kurose, T., Santos, M.V., Kanaya, Y., Ishigami, A., Tanaka, S., and Ito, H. (2021). Effect of Layer Directions on Internal Structures and Tensile Properties of 17-4 PH Stainless Steel Parts Fabricated by Fused Deposition of Metals. Materials, 14.","DOI":"10.3390\/ma14020243"},{"key":"ref_35","doi-asserted-by":"crossref","unstructured":"Suwanpreecha, C., and Manonukul, A. (2022). A Review on Material Extrusion Additive Manufacturing of Metal and How It Compares with Metal Injection Moulding. Metals, 12.","DOI":"10.3390\/met12030429"},{"key":"ref_36","doi-asserted-by":"crossref","unstructured":"Jacob, J., Pejak Simunec, D., Kandjani, A.E., Trinchi, A., and Sola, A. (2024). A Review of Fused Filament Fabrication of Metal Parts (Metal FFF): Current Developments and Future Challenges. Technologies, 12.","DOI":"10.3390\/technologies12120267"},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"2113","DOI":"10.1007\/s40964-024-00570-8","article-title":"Investigating Enhanced Interfacial Adhesion in Multi-Material Filament 3D Printing: A Comparative Study of T and Mickey Mouse Geometries","volume":"9","author":"Frascio","year":"2024","journal-title":"Prog. Addit. Manuf."},{"key":"ref_38","doi-asserted-by":"crossref","unstructured":"Da\u011fl\u0131, S. (2025). Mechanical Characterization and Interface Evaluation of Multi-Material Composites Manufactured by Hybrid Fused Deposition Modeling (HFDM). Polymers, 17.","DOI":"10.3390\/polym17121631"},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"104074","DOI":"10.1016\/j.ijadhadh.2025.104074","article-title":"Analysis of the Interface Properties of Multi-Material Fused Filament Fabricated (FFF) Printed Polymer Composite Structures","volume":"142","author":"Pahari","year":"2025","journal-title":"Int. J. Adhes. Adhes."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"2672","DOI":"10.36922\/msam.2672","article-title":"Enhancing Interlaminar Adhesion in Multi-Material 3D Printing: A Study of Conductive PLA and TPU Interfaces through Fused Filament Fabrication","volume":"3","author":"Goh","year":"2024","journal-title":"Mater. Sci. Addit. Manuf."},{"key":"ref_41","doi-asserted-by":"crossref","unstructured":"Costa, J.M., Sequeiros, E.W., and Vieira, M.F. (2023). Fused Filament Fabrication for Metallic Materials: A Brief Review. Materials, 16.","DOI":"10.20944\/preprints202309.1404.v1"},{"key":"ref_42","first-page":"102854","article-title":"Effect of N2- and CO2-Containing Shielding Gases on Composition Modification and Carbonitride Precipitation in Wire Arc Additive Manufactured Grade 91 Steel","volume":"56","author":"Green","year":"2022","journal-title":"Addit. Manuf."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"110700","DOI":"10.1016\/j.compositesb.2023.110700","article-title":"Silicon Dioxide Nanoparticle Decorated Graphene with Excellent Dispersibility in Natural Rubber Composites via Physical Mixing for Application in Green Tires","volume":"258","author":"Liu","year":"2023","journal-title":"Compos. Part B Eng."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"687","DOI":"10.1007\/s12633-025-03575-2","article-title":"Integrated Microstructural, Mechanical and Machinability Assessment of AlSi10Mg and AlSi10MgCu Alloys: Experimental and RSM-Based Optimization Approach","volume":"18","author":"Alparslan","year":"2025","journal-title":"Silicon"},{"key":"ref_45","doi-asserted-by":"crossref","unstructured":"Alzahrani, F.J., Alzahrani, Y.S., Alamoudi, M.T., and Alkhateeb, M. (2025). A Comprehensive Investigation of Infill Geometry Effects on the Mechanical Performance of Polymer 3D Printed Components. Polymers, 18.","DOI":"10.3390\/polym18010111"},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"115111","DOI":"10.1016\/j.measurement.2024.115111","article-title":"Experimental Research and Optimization Based on Response Surface Methodology on Machining Characteristics of Cast Al-7Si-0.6Mg Alloy: Effects of Cutting Parameters and Heat Treatment","volume":"236","author":"Alparslan","year":"2024","journal-title":"Measurement"},{"key":"ref_47","doi-asserted-by":"crossref","unstructured":"Wang, Z., Wang, L., Tang, F., and Shen, C. (2023). PLA-Based Composite Panels Prepared via Multi-Material Fused Filament Fabrication and Associated Investigation of Process Parameters on Flexural Properties of the Fabricated Composite. Polymers, 16.","DOI":"10.3390\/polym16010109"},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"1596","DOI":"10.1016\/j.jmrt.2025.01.115","article-title":"A Holistic Research Based on RSM and ANN for Improving Drilling Outcomes in Al\u2013Si\u2013Cu\u2013Mg (C355) Alloy","volume":"35","author":"Bayraktar","year":"2025","journal-title":"J. Mater. Res. Technol."},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"113548","DOI":"10.1016\/j.measurement.2023.113548","article-title":"Effects of WEDM and AWJ Cutting Methods on Induction Motor Efficiency and Total Magnetic Losses: Experimental Design and Response Surface Methodology","volume":"221","author":"Bayraktar","year":"2023","journal-title":"Measurement"},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"1752769","DOI":"10.1155\/2024\/1752769","article-title":"The Impact of Various Infill Patterns and Building Orientations on the Mechanical Characteristics and Building Time of PLA Using FDM","volume":"2024","author":"Hamoud","year":"2024","journal-title":"Int. J. Polym. Sci."},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"154","DOI":"10.46793\/adeletters.2024.3.4.2","article-title":"Influence of Infill Density and Number of Layers on Mechanical Properties of 3D Printed PLA and ABS Sandwich Structures","volume":"3","author":"Perak","year":"2024","journal-title":"Adv. Eng. Lett."},{"key":"ref_52","doi-asserted-by":"crossref","unstructured":"Calabrese, L., Marabello, G., Chairi, M., and Di Bella, G. (2025). Optimization of Deposition Temperature and Gyroid Infill to Improve Flexural Performance of PLA and PLA\u2013Flax Fiber Composite Sandwich Structures. J. Manuf. Mater. Process., 9.","DOI":"10.3390\/jmmp9020031"}],"container-title":["Polymers"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2073-4360\/18\/6\/672\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,3,10]],"date-time":"2026-03-10T14:53:45Z","timestamp":1773154425000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2073-4360\/18\/6\/672"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,3,10]]},"references-count":52,"journal-issue":{"issue":"6","published-online":{"date-parts":[[2026,3]]}},"alternative-id":["polym18060672"],"URL":"https:\/\/doi.org\/10.3390\/polym18060672","relation":{},"ISSN":["2073-4360"],"issn-type":[{"value":"2073-4360","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,3,10]]}}}