After nearly a century of dominance as the material of choice for aircraft, metals are seeing increased competition from composite materials in use on Aircrafts. In the modern age, the aerospace industry is also looking ahead to tougher, lighter, and more heat-resistant materials that would lessen emissions, cut fuel costs, and enable higher speeds. So far, in the aviation industry, composites have been the go-to material. “Thirty years ago, five to six percent of an aircraft was made up of composites; now, a plane is made up of about 50% composite material,” said Per Dr. Eleanor Merson, the composite research specialist.
Although metal parts are cheaper to make, their additional weight leads to sub-optimal performance of the system. DARPA launched TFF program in 2016, with aim to develop a versatile composite material and an adaptable forming process to allow affordable fabrication of multiple part configurations from the same work cell. “Eighty percent of small parts are made of metal due to the prohibitive fabrication cost of composite parts under 20 pounds,” said Mick Maher, program manager in DARPA’s Defense Sciences Office. ”
DARPA has launched its Tailorable Feedstock and Forming (TFF) program, which aims to reduce the time and cost burdens associated with current manufacturing design and development cycles for defense platforms. TFF aims to cut the turnaround time for part modifications and redesigns by as much as 50 percent.
The TFF program is seeking a tailorable short-fiber composite feedstock that is stampable and moldable and yields aerospace-grade properties. TFF also seeks technologies to create a tailorable forming work cell capable of manufacturing multiple part configurations with minimal reconfiguration costs and allowing rapid fabrication cycle time.
TFF has two main focus areas—how to make aerospace composite materials more affordable and how to process this new material into useable product form, Maher said. In current composite manufacturing, developing the tools to process materials into products takes a significant amount of time. Any design changes in the platform require redesign of the tools resulting in significant cost and schedule delays.
“Tooling processes can take six to 12 months per design cycle, significantly pushing out the timeline for production,” Maher said. “By developing flexible forming solutions to allow for multiple parts from one work cell, we believe we can shorten the tooling and production cycle for parts—which typically includes an initial design and two re-design periods—down to three years, from today’s average of about six years.”
“If we’re successful, this program should reduce the weight of military systems by making composite parts as affordable as metal, eliminate the lengthy and costly re-tooling burden, and open new design space for small composite parts,” Maher said.
Cost and risk, especially when human life is involved, have impeded the use of advanced composites in commercial and military aircraft; however, these barriers are being overcome as both positive outcomes and user experiences increase. New applications for composite materials and structures emerge every day.
DARPA awards TuFF contract to University of Delaware
The Defense Advanced Research Projects Agency (DARPA) has awarded the University of Delaware Center for Composite Materials (UD-CCM) a $14.9 million three-year cooperative agreement for the Tailorable Feedstock and Forming (TFF) Program.
The objective of this program is to develop a novel low-cost carbon-fiber composite feedstock and manufacturing process. The new material, called TuFF (tailorable universal feedstock for forming), may potentially revolutionize the use of composite materials world-wide, as a cost-effective replacement for small metal parts meeting aerospace performance requirements.
The feedstock will consist of carbon fiber in a thermoplastic matrix with improved microstructural design, creating thin ply sheets that optimize formability of single and doubly curved parts with aerospace grade mechanical properties and damage tolerance
Under the leadership of director Jack Gillespie, UD-CCM seeks establish a semi-automated pilot plant to produce TuFF starting with carbon fiber precursors and ending with net-shape zero-waste formable feedstock blanks. The aim of the pilot plant is to demonstrate the feasibility and scale-up of novel technologies developed through this program with capacity to supply TuFF feedstock to designated industries for evaluation and prototype development.
The success of TuFF as a new material is expected to be transformative for complex curvature composite structures for aerospace and automotive applications in the defense and commercial sectors. “Bypassing all of the manufacturing problems associated with advanced composites, our approach will allow us for the first time to make composite parts having aerospace properties at automotive prices,”said Rob Adkinson, TuFF program manager.
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