The evolving requirement of the U.S. strategic missile programs have required the continual development of highly capable advanced composite materials such as Carbon/Carbon (C/C) and Ceramic Matrix Composites (CMCs) to deliver differentiated missile performance.
Currently, there are limitations on the size and manufacturing throughput capacity of large C/C and CMC shapes for hypersonic missile nosetip applications. Specifically, the C/C and CMC parts are densified using multiple cycles to arrive at the optimal density required to meet missile re-entry stability performance requirements. There are also maximum size manufacturing capability challenges for these specialized parts. Increasing demand for larger hypersonic nosetip material end items necessitates new business processes and associated nosetip technologies that enable faster processing times and increased throughput capability. Resolution of the processing time increases missile nosetip production throughput and achieves affordable solutions.
Part of the challenge is the time required for manufacturing parts and machining the parts into their final configuration as many of the DoD programs are requiring classified facilities for multiple phases of production. The capability to machine large carbon/carbon parts in this type of setting rests with a very limited set of vendors and requires the shipment and transportation of classified parts to between densification location and machining location. This often results in multiple trips. It is not uncommon for parts to log more than 5000 miles between the material fabricator and machine shop locations. Having the capability of machining these parts residing with a vendor who also fabricates the parts will save time, cost, and reduce risk of damage/spillage of sensitive parts while in transit.
Technologies of interest include:
- Near Net Shaped component and aeroshell scale-up part count reduction, design, simplification, performance enhancement, and risk reduction;
- fabrication, densification, and machining of high-density re-entry grade C/C and CMC Thermal Protection System (TPS) materials;
- Three Dimensional (3D) reinforced fine-weave architectures applied to scaled-up TPS applications; and
- Off the shelf fiber modifications to enable fabrication of tailored textile architectures for TPS components.
This tasking requires the ability to produce 3D C/C and CMC materials and machining of those materials to enhance and optimize missile performance per Navy requirements. This may include: graphite fiber yarn management/pre-treatments; automatic 3D weaving of large graphite fiber preforms; tailored pitch resin densification of these preforms into C/C billets, and the formation of localized ceramic regions within Shape Stable Nosetips (SSNT) billets. Additionally, the skills, knowledge, capabilities, and facilities (or facilities access) for the specialized high-pressure pitch resin impregnation C/C densification process and/or development of the required localized ceramic regions within SSNT billets is required. The resulting 3D C/C materials must hold/exhibit strength in 3 directions (X,Y,Z axis) using 3D C/C with high pressure densification, or equivalent processes, to achieve a shape stable nose tip for consistent nosetip ablation.