Additively Manufactured High Performance Carbon Fiber Composites

National Laboratory: 
Lawrence Livermore National Laboratory
Characterization Class: 
Non-destructive examination
Computational Tools Class: 
Materials Processing
Structure-Properties
Processing/Manufacturing Class: 
Fabrication and synthesis
Thermo-mechanical processing
Description: 

LLNL has developed a capability for additively manufacturing carbon fiber thermoset composites via direct ink writing micro-extrusion technology. LLNL can control fiber placement in 2.5 dimensions with a high degree of precision and control fiber alignment to manufacture orthogonal, oriented composite materials. The toolpaths printed are computationally optimized to maximize strength and stiffness and minimize part weight. LLNL also has unique high-performance computational modeling resources and expertise in fiber composite design, performance prediction, and process modeling, as well as large area, multi-axis mandrel winder systems for the production of high-performance continuous carbon fiber composite parts. LLNL regards these capabilities as an advance in the field of lightweight carbon fiber composite materials that have the potential to afford production of complex, three-dimensional (3D) carbon fiber parts with better defined and improved physical properties over conventional pressed carbon fiber thermoset parts.

Capability Bounds: 

Current maximum direct ink write part build size is ~200 cubic inches, and the maximum single nozzle print speed is ~5 cm/min. Maximum resolution is 250 μm. There is capability to scale through paralleling. Developmental mandrel winder capabilities at LLNL allow the production of complete test parts and assemblies on an upper size scale bound of ~12 feet per single build.

Unique Aspects: 

LLNL distinctly offers direct ink write printing of carbon fiber thermoset feedstocks at high resolution with the ability to 3D print high-performance thermoset materials in real time. Unique computational optimization capability is available to design optimal part microstructures and translate those to printable toolpaths. In addition, unique computational predicative modeling capabilities exist for both large-scale discrete fiber flow processes and dynamic composite performance and property simulation. LLNL also offers flexible intermediate-to-production-scale multi-axis winder systems to produce continuous carbon fiber composites that can use novel resin feedstocks for enhanced performance.

Availability: 

Current manufacturing limitations are based on the availability of printers and winders (heavily subscribed for multiple research and development projects). As such, time must be planned in advance. High-performance computing computation time also is in high demand. Thus, estimated usage (CPU hours/month) must be agreed upon and approved in advance.

Single Point of Contact: 

James P Lewicki, AM feedstock development and CF printing technology POC, lewicki1@llnl.gov

References: 
  1. Shape-morphing composites with designed micro-architectures Jennifer N. Rodriguez, Cheng Zhu, Eric B. Duoss, Thomas S. Wilson, Christopher M. Spadaccini & James P. Lewicki Scientific Reports 6, Article number: 27933 (2016) doi:10.1038/srep27933
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