Fine Braided Tungsten Reinforced Ceramic Composites for Ultra Sharp Structures Navy SBIR FY2014.2 Sol No.: Navy SBIR FY2014.2 Topic No.: N142-119 Topic Title: Fine Braided Tungsten Reinforced Ceramic Composites for Ultra Sharp Structures Proposal No.: N142-119-0804 Firm: Materials Research & Design 300 E. Swedesford Rd Wayne, Pennsylvania 19087-1858 Contact: Kent Buesking Phone: (610) 964-6130 Web Site: www.m-r-d.com Abstract: Future hypersonic vehicles will be required to fly extended, long term trajectories where the bod-ies must exhibit high lift-to-drag (L/D) ratios. The need for reduced drag means that the nosetips and leading edges must have small radii, shallow wedge angles, and be erosion resistant. Desira-ble dimensions include a nose radius on the order of 0.040 inch and a wedge half angle of about 3�. This radius is an order of magnitude finer than the existing state of the art. Existing carbon-carbons and ceramic matrix composites (CMCs) made with commercial carbon yarns (2K and 3K tows) result in nosetips and leading edges with radii of 0.5 inch or greater. Fine radii also create operational problems because aerodynamic heat loads increase as the radius decreases. This means that high L/D nosetips and leading edges will be exposed to high temperatures in an oxi-dizing environment for long periods of time. Thus in order to maintain a sharp radius the nosetips and leading edges must be erosion resistant and able to withstand significant thermal stresses. Thus the problem is to develop low erosion, thermal stress resistant ceramic matrix com-posites at a geometric scale that is an order of magnitude finer than the existing state of the art. In order to solve this problem Materials Research & Design (MR&D) proposes to develop fine braided tungsten (W) wire CMCs that meet the goals for fine geometry, low erosion, and thermal stress resistance. The proposed effort builds upon past successful collaborations between MR&D and two other businesses. Specifically DE Technologies (DET) and MR&D have de-signed, analyzed, developed and demonstrated high strength tungsten reinforced braided com-posites for severe impact applications. Additionally MR&D has supported Exothermics in the development of manufacturing methods to densify chopped W/HfN composites for high temper-ature erosion resistant CMCs. The proposed Phase I program will bring this team together to de-sign, analyze, fabricate, and characterize fine braided W/HfN CMC leading edges. MR&D will manage the program, analyze the response of the CMC to a hypersonic trajectory, and design braid architectures that will survive the conditions. DET will braid both representative leading edge preforms and additional preforms for densification and characterization. Exothermics will densify the braided tungsten preforms using their process of hafnium slurry infiltration followed by nitridation and HIPping. If this Base program is successful, braided W/HfN billets will be characterized at SoRI as part of the Option for critical material properties including thermal con-ductivity, thermal expansion, and high temperature strength. Benefits: If successful, the materials and processes will result in future applications in commercial space vehicles, high performance turbine engines, and hypersonic projectiles. Return