TY - JOUR

T1 - Identification of hybridization strategies for combining fused filament fabrication with unidirectional tape reinforcement

AU - Matkovic, Nikolas

AU - Höger, Katja

AU - Friedmann, Marco

AU - Stamer, Florian

AU - Fleischer, Jürgen

AU - Lanza, Gisela

N1 - Publisher Copyright: © 2023 Elsevier Ltd

PY - 2023/2

Y1 - 2023/2

N2 - Additive manufacturing processes such as fused filament fabrication (FFF) enable highly individualized production with thermoplastics, can thus produce load-path-optimized components and therefore lightweight structures. Since the mechanical properties of FFF are lower than those of traditional processes, discontinuous and continuous fibers are used to improve the mechanical properties. Currently the reinforcement effect of continuous fibers cannot be fully utilized in FFF due to the lack of impregnation of the fibers and only low processing pressures during hybridization. To tackle this challenge, four strategies for hybridization of pre-impregnated unidirectional (UD) carbon fiber tapes with polyamide 6 (PA6) matrix and FFF-printed parts are investigated in this work. The strategies differ in the timing of the application of consolidation steps, i.e. a controlled application of heat and pressure in the interface between FFF-layers and UD-tape. With the use of mechanical pull-out tests, the maximum achievable shear stresses of the interface are investigated. Additional computed tomography (CT) scans of the interfaces allow the four hybridization strategies to be evaluated. It is shown that even a single consolidation in the right process step significantly increases the adhesion between UD-tape and FFF layer leading to about 100–200% increased shear stresses before delamination occurs. To ensure the transferability of the hybridization strategies to other material systems and to validate the results, filaments of pure PA6 as well as PA6 with short glass and carbon fibers were used for the FFF process.

AB - Additive manufacturing processes such as fused filament fabrication (FFF) enable highly individualized production with thermoplastics, can thus produce load-path-optimized components and therefore lightweight structures. Since the mechanical properties of FFF are lower than those of traditional processes, discontinuous and continuous fibers are used to improve the mechanical properties. Currently the reinforcement effect of continuous fibers cannot be fully utilized in FFF due to the lack of impregnation of the fibers and only low processing pressures during hybridization. To tackle this challenge, four strategies for hybridization of pre-impregnated unidirectional (UD) carbon fiber tapes with polyamide 6 (PA6) matrix and FFF-printed parts are investigated in this work. The strategies differ in the timing of the application of consolidation steps, i.e. a controlled application of heat and pressure in the interface between FFF-layers and UD-tape. With the use of mechanical pull-out tests, the maximum achievable shear stresses of the interface are investigated. Additional computed tomography (CT) scans of the interfaces allow the four hybridization strategies to be evaluated. It is shown that even a single consolidation in the right process step significantly increases the adhesion between UD-tape and FFF layer leading to about 100–200% increased shear stresses before delamination occurs. To ensure the transferability of the hybridization strategies to other material systems and to validate the results, filaments of pure PA6 as well as PA6 with short glass and carbon fibers were used for the FFF process.

KW - Additive manufacturing

KW - Computed tomography

KW - Fiber reinforcement

KW - Hybridization

KW - Engineering

UR - http://www.scopus.com/inward/record.url?scp=85145739129&partnerID=8YFLogxK

U2 - 10.1016/j.coco.2022.101484

DO - 10.1016/j.coco.2022.101484

M3 - Journal articles

AN - SCOPUS:85145739129

VL - 38

JO - Composites Communications

JF - Composites Communications

SN - 2452-2139

M1 - 101484

ER -