Loughborough: Tests In Continuous Carbon Fiber Composites in 3D Printing With FDM and SLA

Share this Article

UK researchers continue to explore the benefits of creating new composites for 3D printing. Here, they discuss their findings regarding carbon composites used in SLA 3D printing and material extrusion, outlined in their recently published paper, ‘Fabrication of the continuous carbon fiber reinforced plastic composites by additive manufacturing.’

As authors Y. Lu, G.K. Poh, A. Gleadall, L.G. Zhao, and X. Han explain, composites are often created due to a need for stronger mechanical properties in 3D printed and additive manufactured parts. Carbon is a material relied on especially in applications like the automobile industry and aerospace because of incredible strength, but also the potential for making lightweight parts that may not have been possible previously.

The authors point out that while carbon fiber is useful for strengthening mechanical properties, it often still displays limited strength in tensile testing. This is due to a lack of control over short fibers, resulting in more unpredictable orientation and alignment during 3D printing. Beyond that, inferior bonding of the composite fibers and the matrix may also cause a lack of integrity in structures. In testing, the researchers used continuous-fiber-reinforced composites (CFRCs) in material extrusion and SLA processes.

Testing was performed through physical evaluation of the mechanical properties, along with examination by microscope. Samples were created specifically for tensile testing, with Accura60 resin used for SLA 3D printing (with carbon fiber filament obtained from Markforged) and nylon and carbon fiber filament, also supplied by Markforged, used for material extrusion on a MarkTwo 3D printer. Tensile tests were then completed on an Instron 3369 machine with a 50 kN load cell, and then analyzed further through a Primotech microscope, with the fiber-matrix interface examined via a Hitachi TM3030 Tabletop scanning electron microscope.

ASTM D638-02a Tensile test specimen sample geometry (dimensions in mm).

Sample code and material specification

“The increase of elastic modulus after embedding carbon fiber is 110.49% and 23.69% for ME and SLA based composite samples, respectively. Compared with theoretical result, experimental results demonstrated a 73.3% lower tensile modulus for ME samples and a 42.06% lower tensile modulus for SLA samples,” reported the authors. “The microscopic analysis suggested a presence of porosity at the fibre-matrix interface of the composite specimens produced by both SLA and ME while SLA samples have a less percentage of porosity.”

(a) 2D plane view of fibre distribution of ME-C sample; (b) Cross Section view of SLA-C matrix sample

While the elastic modulus was increased substantially with carbon fiber, the authors pointed out that it also significantly reduced elongation at break, due to a lower elongation-to-break—in comparison to the use of all nylon material. Because of this, the sample was brittle. They also noticed high porosity due to voids in the fiber/matrix layers—leading to decreased mechanical performance. It was noted that this could be due to inferior infill density, with printed fibers not being even distributed during 3D printing—leading to ‘compromised’ tensile properties.

“Compared with theoretical result, experimental results demonstrated a 73.3% lower tensile modulus for ME samples and a 42.06% lower tensile modulus for SLA samples. The microscopic analysis suggested a presence of porosity at the fibre-matrix interface of the composite specimens produced by both SLA and ME while SLA samples have a less percentage of porosity,” stated the researchers.

Fracture sections of ME-C samples (a and b) and SLA-C samples (c and d)

“Compared to commercially available composite ME based machine, SLA technology showed promising results for composite manufacturing, and further investigation is ongoing,” concluded the researchers.

One of the most fascinating parts of 3D printing is not only the innovations that spring forth from the technology continually, but also the ongoing refinements in machines and materials. And while one type of plastic or metal may be suitable for a range of applications, users often find that by adding another material or element, they can strengthen or stabilize parts further, whether in using metals like titanium or a mixture of graphene and alginate, or recycling wood into 3D printed composites. What do you think of this news? Let us know your thoughts! Join the discussion of this and other 3D printing topics at 3DPrintBoard.com.

[Source / Images: ‘Fabrication of the continuous carbon fiber reinforced plastic composites by additive manufacturing’]

Share this Article


Recent News

The State of 3D Printing in Heavy Equipment

Interview with Tibor van Melsem Kocsis of DiManEx on 3D Printing in the Supply Chain



Categories

3D Design

3D Printed Art

3D Printed Food

3D Printed Guns


You May Also Like

Sponsored

Top 5 Software Packages for 3D Printing

3D printing is a tough job. Although once learned, it does not seem too tricky. However, for beginners, it might not seem as friendly as various other new technologies. The...

3D Printing News Briefs: November 5, 2019

We’ve got some formnext announcements to start off today’s 3D Printing News Briefs – atum3D is introducing its newest DLP 3D printer, while Incus GmbH plans to launch its new...

Neighborhood 91: End-to-End 3D Printing Ecosystem at Pittsburgh International Airport

There are many 3D printing clusters around the world, specializing in areas like 3D bioprinting and research. But we’ve never seen one that includes all the elements of the AM...

Daimler Buses Relies on DyeMansion for Color & Texture Quality in 3D Printed Spare Parts

While it took decades for the rest of the world to catch up, a handful of aerospace organizations, automotive industry leaders, and other innovators have continued to enjoy the inside...


Shop

View our broad assortment of in house and third party products.


Services & Data

Subscribe To Our Newsletter

Subscribe To Our Newsletter

Join our mailing list to receive the latest news and updates from our 3DPrint.com.

You have Successfully Subscribed!