Fracture toughness of additively manufactured carbon fiber reinforced composites

Abstract The fracture properties (stress intensity factor and energy release rate) of additively manufactured (AM) polylactic acid (PLA) and its short carbon fiber (CF) reinforced composites have been studied. The effects of CF reinforcement, nozzle geometry and bead lay-up orientations in fracture properties, void contents, and interfacial bonding were investigated. The fused filament fabrication (FFF)-based AM specimens using both circular and square shaped nozzle were printed and compared with the conventional compression molded (CM) samples. Compact tension (CT) specimens with different CF concentrations (0 wt.%, 3 wt. %, 5 wt.%, 7 wt.% and 10 wt.%) were printed with two bead lay-up orientations ( 45 0 / - 45 0 and 0 0 / 90 0 ) using PLA and CF/PLA composite filaments. The results show significant improvement in fracture toughness and fracture energy for CF/PLA composites in comparison to neat PLA. The fracture toughness was increased by 42% for 0 0 / 90 0 and 38% for 45 0 / - 45 0 bead orientations, respectively with 5% CF loading. The increase in fracture energy was observed to be about 77% for 0 0 / 90 0 and 88% for 45 0 / - 45 0 bead orientations, respectively for the same fiber reinforcement (5 wt. %). Such improvement in fracture properties is expected to be higher for all 90 0 bead orientations. The samples printed by square-shaped nozzle showed enhanced fracture toughness with less inter-bead voids and larger bonded areas in comparison to the circular-shaped nozzle. Although the fracture toughness showed very negligible differences between 0 0 / 90 0 and 45 0 / - 45 0 specimens, distinguishable variation may be seen in the case of 0 0 and 90 0 bead orientations. The crack propagation path and fracture mechanisms were studied using optical microscopy (OM) and scanning electron microscopy (SEM) examinations. Fractography revealed different modes of failure with a very high fiber orientation along the printing direction and a relatively higher void contents for 7 and 10 wt. % fiber reinforcement.

[1]  R. Poprawe,et al.  Laser additive manufacturing of metallic components: materials, processes and mechanisms , 2012 .

[2]  Liang Hou,et al.  Additive manufacturing and its societal impact: a literature review , 2013 .

[3]  Yong Li,et al.  Measurements of the mechanical response of unidirectional 3D-printed PLA , 2017 .

[4]  Tim A. Osswald,et al.  Process-Induced Fiber Orientation in Fused Filament Fabrication , 2018, Journal of Composites Science.

[5]  Frederik L. Giesel,et al.  3D printing based on imaging data: review of medical applications , 2010, International Journal of Computer Assisted Radiology and Surgery.

[6]  K. Arakawa,et al.  Effects of isothermal crystallization on fracture toughness and crack growth behavior of poly (lactic acid) , 2005 .

[8]  K. Lozano,et al.  Nanofiber-reinforced polymers prepared by fused deposition modeling , 2003 .

[9]  W. Cong,et al.  Additive manufacturing of carbon fiber reinforced thermoplastic composites using fused deposition modeling , 2015 .

[10]  Kaufui Wong,et al.  A Review of Additive Manufacturing , 2012 .

[11]  G. Pinter,et al.  Fracture mechanical characterization and lifetime estimation of near-homogeneous components produced by fused filament fabrication , 2018 .

[12]  F. Melchels,et al.  A review on stereolithography and its applications in biomedical engineering. , 2010, Biomaterials.

[13]  Douglas E. Smith,et al.  Effects of extrudate swell and nozzle geometry on fiber orientation in Fused Filament Fabrication nozzle flow , 2016 .

[14]  L. Love,et al.  Highly oriented carbon fiber–polymer composites via additive manufacturing , 2014 .

[15]  Robert J. Strong,et al.  A review of melt extrusion additive manufacturing processes: I. Process design and modeling , 2014 .

[16]  K. Chrissafis.  Detail kinetic analysis of the thermal decomposition of PLA with oxidized multi-walled carbon nanotubes , 2010 .

[17]  R. T. L. Ferreira,et al.  Experimental characterization and micrography of 3D printed PLA and PLA reinforced with short carbon fibers , 2017 .

[18]  Jianzhong Fu,et al.  Evaluation of carbon fiber-embedded 3D printed structures for strengthening and structural-health monitoring , 2017 .

[19]  Tait D. McLouth,et al.  Influence of processing and orientation print effects on the mechanical and thermal behavior of 3D-Printed ULTEM® 9085 Material , 2017 .

[20]  H. Anuar,et al.  Effect of Plasticizer on Fracture Toughness of Polylactic Acid Reinforced with Kenaf Fibre and Montmorillonite Hybrid Biocomposites , 2016 .

[21]  Hui Wang,et al.  Additive manufacturing of carbon fiber-reinforced plastic composites using fused deposition modeling: Effects of process parameters on tensile properties , 2017 .

[22]  Wai Yee Yeong,et al.  Characterization of mechanical properties and fracture mode of additively manufactured carbon fiber and glass fiber reinforced thermoplastics , 2018 .

[23]  L. Love,et al.  The importance of carbon fiber to polymer additive manufacturing , 2014 .

[24]  Dichen Li,et al.  Interface and performance of 3D printed continuous carbon fiber reinforced PLA composites , 2016 .

[25]  Ming-Chuan Leu,et al.  Progress in Additive Manufacturing and Rapid Prototyping , 1998 .

[26]  Xin Wang,et al.  3D printing of polymer matrix composites: A review and prospective , 2017 .

[27]  Anwarul Haque,et al.  Tensile properties, void contents, dispersion and fracture behaviour of 3D printed carbon nanofiber reinforced composites , 2018 .

[28]  Yaling Liu,et al.  Shear induced alignment of short nanofibers in 3D printed polymer composites , 2016, Nanotechnology.

[29]  V. Kovan,et al.  Effect of layer thickness and print orientation on strength of 3D printed and adhesively bonded single lap joints , 2017 .

[30]  Wei Jiang,et al.  3D Printable Graphene Composite , 2015, Scientific Reports.

[31]  Yingguang Li,et al.  Rapid prototyping of continuous carbon fiber reinforced polylactic acid composites by 3D printing , 2016 .

[32]  Rupinder Singh,et al.  Effect of SiC/Al2O3 particle size reinforcement in recycled LDPE matrix on mechanical properties of FDM feed stock filament , 2018, Virtual and Physical Prototyping.

[33]  W. C. Smith,et al.  Structural characteristics of fused deposition modeling polycarbonate material , 2013 .

[34]  Martin Lévesque,et al.  Direct-write fabrication of freestanding nanocomposite strain sensors , 2012, Nanotechnology.

[35]  P. Wright,et al.  Anisotropic material properties of fused deposition modeling ABS , 2002 .

[36]  E. Shin,et al.  Additive Manufacturing and Characterization of Ultem Polymers and Composites , 2015 .

[37]  Ehud Kroll,et al.  Enhancing aerospace engineering students' learning with 3D printing wind‐tunnel models , 2011 .

[38]  D. B. Pedersen,et al.  Distribution and Orientation of Carbon Fibers in Polylactic Acid Parts Produced by Fused Deposition Modeling , 2016 .

[39]  J. Lewis,et al.  3D‐Printing of Lightweight Cellular Composites , 2014, Advanced materials.

[40]  W. Zhong,et al.  Short fiber reinforced composites for fused deposition modeling , 2001 .

[41]  J. Li,et al.  The Effect of Nitric Acid Oxidization Treatment on the Interface of Carbon Fiber-Reinforced Thermoplastic Polystyrene Composite , 2009 .

[42]  Anthony Atala,et al.  3D bioprinting of tissues and organs , 2014, Nature Biotechnology.

[43]  B ShortDaniel,et al.  Use of 3D Printing by Museums: Educational Exhibits, Artifact Education, and Artifact Restoration , 2015 .

[44]  Branko Kolarevic.  Digital Fabrication: Manufacturing Architecture in the Information Age , 2001 .

[45]  Tait D. McLouth,et al.  The impact of print orientation and raster pattern on fracture toughness in additively manufactured ABS , 2017 .

[46]  P. Dudek,et al.  FDM 3D Printing Technology in Manufacturing Composite Elements , 2013 .

[47]  P. Wright,et al.  Material Characterization of Fused Deposition Modeling (FDM) ABS by Designed Experiments , 2001 .

[48]  H. Thomas Hahn,et al.  Characterization of the laminated object manufacturing (LOM) process , 2000 .