Removable Smart Tooling for High-Temperature Composite Fabrication

The work described in this proposal will facilitate the application of automated tape placement (ATP) and automated fiber placement (AFP) of thermoplastic-matrix composites for a range of complex Navy components and structures. The goal of the work will be to develop removable tooling to produce complex contours directly by AFP/ATP, thus eliminating the need to make complex parts from multiple sections that are joined together later.Relying on years of experience in the advanced composites industry, the principals of Nevada Composites have developed Green-AeroSM tooling for composites—lightweight ceramic tooling that is stable under high pressure and long-duration cure cycles and can be washed out with water after cures to the highest resin-matrix-composite cure temperatures. The tooling provides tight tolerances, offers a linear, composite-compatible coefficient of thermal expansion and a low thermal mass, accommodates cure pressures to 1400 kPa (200 psi) or more, and is environmentally friendly. It has been demonstrated to be sufficiently durable to be used repeatedly and successfully in a variety of both commercial and military 121°C (250°F), 177°C (350°F), and 230°C (450°F) applications as well as in several 370°C (700°F) demonstrations for aircraft engine components. It has been used in hand layup/autoclave cure, filament winding, ATP, vacuum-assisted resin-transfer molding (VARTM), and other processes. Because of its broad range of temperature capability and stability, Green-AeroSM tooling also offers the potential of qualifying a tooling solution for a 177°C (350°F)-cure application and then using the same tooling for increasingly higher temperature exposures to 370°C (700°F) and above. During Phase I we will verify that G-A tooling provides the properties required for AFP/ATP of carbon-fiber (CF) in a matrix of polyetheretherketone (PEKK), and does so at the target cost of $40-$50 per part of size 1.5” x 12”x 0.5”. Properties will include tolerances, processing time, coefficient of thermal expansion, matrix-compatibility, shelf stability, and others. We will also investigate whether gas-hardening of G-A tooling can help meet or improve these properties while improving tool fabrication speed and, if so, explore improvements in shelf stability of gas-hardened tooling. During the Option we will further develop gas-hardening as needed to meet requirements. We will continue long-term testing and investigate whether a tool coating is needed and, if so, whether coating changes are required for CF/PEKK composites. We’ll also investigate the long-term availability of the gas-hardening binder and whether reformulation is needed for fabrication of complex CF/PEKK parts. With input from our Technical Point of Contact (TPOC) we’ll also find an appropriate commercial or research partner to work with in Phase II who will both use and evaluate our tooling for AFP/ATP of complex thermoplastic-matrix parts.