Low-Density Ablator-Filled Foam Incorporating Lyocell-Derived Carbon Fiber for BMDS Interceptors

In previous exit cone liner work and heat shield fabrication, Ultramet developed and demonstrated advanced foam-reinforced carbon/phenolic ablators that offer substantially increased performance under high heat flux conditions and reduced weight relative to conventional ablators. Solid rocket motor and arcjet test results showed that the foam provides effective reinforcement for a conventional chopped fiber ablator and helps to retain the char layer, which reduces the erosion rate and the pyrolysis rate of the underlying virgin ablator, thereby reducing heat transfer. The composite offers good strength and stiffness, does not suffer from delamination and pocketing issues that can occur in continuously reinforced ablators, and has demonstrated high resistance to alumina particulate erosion. However, the ablator formulation in ablator-filled foam contains rayon-derived carbon fiber from Enka (Germany) to minimize thermal conductivity. The potential exists to replace rayon-derived fiber with an alternative fiber that is domestically manufactured using a process that is not damaging to the environment.Approved for Public Release | 17-MDA-9219 (31 May 17)