C-C material systems have high strength:weight ratios at high temperatures, making them well suited for future hot structure designs. However legacy C-C solutions are subject to poor through thickness properties (for 2D laminates), or manufacturing speed and capacity issues (for Cartesian billets.) These issues are often compounded for tubular or conical geometries.
With this SBIR Phase I submission TEAM, Inc. proposes to advance the state art for tubular and conical preforming methods for use in C-C hot structure applications. A parallel process development and testing program is proposed:
Process Development: We will use “off the shelf” and versatile braiding technology to demonstrate fabrication of conical, carbon fiber preform(s) with up to 1” wall thickness and conical geometry. We will modify TEAM's custom designed, automated z-stitching line to insert stitches into a conical geometry preform at controlled and repeatable spacing(s).
In parallel with the process development, we will quickly fabricate flat panel test coupons of stitched and un-stitched braided laminates. (A phenolic-resin system will be used to meet cost and schedule constraints in Phase I.) ~Half the panels will be tested by partner Southern Research Institute to characterize in-plane and inter-laminar tensile properties of stitched vs. un-stitched variants. The other ~half of panels will be delivered as-is for potential C-C densification and testing by NASA or by TEAM at beginning of Phase II.
The advantage of the proposed approach is that both the braiding process and the stitching work cell are easily scaled in terms of part size and geometry. Through thickness property issues with traditional C-C tape-lay are addressed by the proposed stitching process. Cost / capacity / geometric constraint issues associated with Cartesian / Polar billets are addressed by versatility and relative speed of the braiding and z-stitching processes.
Potential NASA users of this technology exist for a variety of propulsion systems, including upper stage engine systems, in-space propulsion systems, Lunar/Mars lander descent/ascent, solid motor systems, including those for primary propulsion, hot gas valve applications, and small separation and/or attitude control systems. Potential programs of interest include Commercial Orbiter Transportation Services (COTS), Commercial Lunar Payload Services (CLPS) and NASA HEOMD programs including Space Launch System (SLS) and Human Landing System (HLS).
The proposed C-C preforming & material system proposed here-in is of great interest to various DoD stakeholders currently developing hypersonic missile and vehicle systems. (Army, Navy, Air Force, DARPA and their prime contractors). The technology would likely be applied as TPS or hot structure for aeroshell bodies, frustras, nose-tip adaptors, leading edges and other control surfaces.