High Rate and High Performance Joining of Composites

National Laboratory: 
Oak Ridge National Laboratory
Characterization Class: 
Extreme Environment Testing
Mechanical Behavior of Materials
Non-destructive examination
Computational Tools Class: 
Structure-Properties
Processing/Manufacturing Class: 
Joining
Description: 

ORNL has experience using microwaves to develop joining of polymeric products. Microwave-based joining of polymeric products has been developed via deposition of an electrically conductive material upon one of the thermoplastic surfaces followed by exposure to microwave radiation so the thermoplastic surfaces in contact melt and diffuse under an applied pressure. The deposited material has a preferred thickness, no greater than a skin depth, which is related to the microwave radiation frequency and characteristics of the deposited material. The ORNL team also has initiated work on joining composite surfaces using laser structuring, which allows for a transition of the surface failure mode from the adhesive/adherend interface to the bulk of the material and provides a 2x increase in joint energy absorption capabilities. The team also has experience in developing novel test methods for harsh conditions or multiple types of specimens. ORNL typically works with automotive original equipment manufacturers (OEMS) to develop joining technologies of similar and dissimilar materials and develops joint failure models and novel nondestructive evaluation (NDE) methods for joints.

Capability Bounds: 

Applicability range extends from small coupon testing to beta-scale factory testing.

Unique Aspects: 

The team members have broad knowledge of polymer synthesis, modification, characterization, and applications. ORNL has a multidisciplinary team that offers expertise in composites, metals, joining, computational modeling, NDE, and unique testing capabilities for multi-material joints.

Availability: 

All technologies are available for industrial collaboration. A few specialized tools are available for researchers through user program.

Single Point of Contact: 

Name: Dr. Felix Paulauskas, Senior Carbon Fiber Researcher
Email: paulauskasfl@ornl.gov
Phone: 865-576-3785 (Composites)

References: 
  1. Paulauskas FL, Meek TT. US Patent 5,603,795 (1997).
  2. Paulauskas FL, et al. US Patent 5,798,395.
  3. Paulauska FL, et al. US Patent 5,804,801.
  4. 'Surface Characterization of Carbon Fiber Polymer Composites and Aluminum Alloys after Laser Interference Structuring,' Adrian S. Sabau, Clayton M. Greer, Jian Chen, Charles D. Warren, and Claus Daniel, 2016 TMS Annual Meeting & Exhibition, Nashville, TN, March, 2016.
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