High Strength, Nano-Grained Tungsten for Zero-Erosion Nozzle Throat Inserts

Zero erosion solid rocket nozzle materials are an enabling material for next generation solid rocket motors that are being designed to operate at higher temperatures and pressures and for longer burn times. High thrust solid rocket motors (SRMs) can be achieved by using aluminized propellants and high motor pressures. However, the increased pressures result in flame temperatures in excess of 6000F. Tungsten has been identified as a low cost, erosion resistant throat material capable of operating at these extreme temperatures. However, higher strength tungsten is necessary to fabricate the thin-walled liners targeted for weight reduction goals, while still being able to handle the high pressures and thermal stress gradients. A nanograined tungsten has been developed that has greater than a 3x improvement over the strength of typical tungsten. This Phase II effort will develop a property database of ambient and elevated temperature mechanical and thermal properties such that nanograined tungsten throat liners can be designed and fabricated. These throat liners will be test fired in solid rocket motors, and their performance will be evaluated.