Effect of Fiber Volume Fraction and Heat Treatment on the Mechanical Properties of Material-Extrusion-Printed Continuous Glass-Fiber-Reinforced Onyx Composites
JOURNAL OF MATERIALS ENGINEERING AND PERFORMANCE, 2026 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Basım Tarihi: 2026
- Doi Numarası: 10.1007/s11665-026-15043-y
- Dergi Adı: JOURNAL OF MATERIALS ENGINEERING AND PERFORMANCE
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Applied Science & Technology Source, Chemical Abstracts Core, Compendex, INSPEC, Engineering Source (EBSCO), Materials Science & Engineering Collection (ProQuest), Technology Collection (ProQuest)
- Anahtar Kelimeler: continuous-fiber reinforcement, fiber volume fraction, glass-fiber composites, heat treatment, Onyx
- Gazi Üniversitesi Adresli: Evet
Özet
The mechanical performance of continuous-fiber-reinforced thermoplastic composites produced via material extrusion is significantly affected by the reinforcing architecture and post-processing conditions. However, the combined effects of fiber volume fraction and heat treatment on continuous glass-fiber-reinforced Onyx composites have not been sufficiently clarified. In this study, continuous glass-fiber-reinforced Onyx specimens were fabricated using a Markforged Mark Two material-extrusion system, and the effects of fiber volume fraction and post-processing heat treatment on tensile and flexural behavior were systematically investigated. The fiber volume fraction varied from 18.85 to 32.61% in tensile specimens and from 17.78 to 31.05% in flexural specimens by changing the number and position of fiber-reinforced layers while maintaining constant printing parameters and matrix architecture. Heat-treated specimens were annealed at 120 degrees C for 120 min in an air atmosphere. Tensile strength increased from 149.6 to 218.5 MPa as the fiber volume fraction increased from 18.85 to 32.61%. Heat treatment further improved tensile strength by 2.7-7.1%, with limited change in elongation at break. In flexural loading, the maximum recorded flexural stress ranged from 93.2 to 135.9 MPa in the as-built condition, while heat treatment produced configuration-dependent changes, including increases of up to 20.4%. The non-monotonic flexural response observed at higher fiber contents indicates that layer positioning relative to the neutral axis is as important as total reinforcement content under bending-dominated loading. These results show that the mechanical performance of glass-fiber-reinforced Onyx composites is governed not only by fiber volume fraction but also by fiber-layer architecture and thermal post-processing. The findings provide practical guidance for optimizing material-extrusion-printed composite structures requiring improved tensile and flexural performance.