Enabling robust solutions for effective performance.
Advanced composites enable many applications due to their high temperature strength and low density. The high temperature capability allows them to comfortably operate in ranges where metallic structures would melt or have virtually no residual strength. Their low density reduces stress in rotating components and momentum in moving parts, while their high specific strength (strength divided by density) often lowers the overall system mass.
The Pratt & Whitney Rocketdyne extreme engineering team has been actively integrating advanced composites into our products for more than 30 years. We have fully integrated materials, design and thermostructural analysis capabilities that allow us to design and deploy robust, highly operable components. Our experience base of deployed systems includes rotating turbomachinery components, turbine stators, liquid rocket engine thrusters from 100 – 40,000 lbs of thrust, injector face plates, nozzle extensions, space heat exchangers, and aerodynamic control surfaces for space reentry vehicles. We also have vast experience fabricating test and demonstration hardware for low-temperature structural needs, as well as advanced terrestrial energy systems.
Advanced Composites Features
Advanced Metallurgy and Alloy Development
Pratt & Whitney Rocketdyne has more than 50 years of experience in pushing metallic alloy systems to their limits, as well as developing new alloys to meet our challenging needs. We have significant experience in a number of areas, including lightweight structural alloy development, rapid prototyping, powder metallurgy, oxygen and hydrogen compatibility testing and alloy selection for terrestrial power applications, including molten salt and liquid metal cooling loops for solar and nuclear power production.
Pratt & Whitney Rocketdyne’s alloy development activities, and related intellectual property, span the breadth of the metallic world, with well-known alloys such as NARloy-Z, Tens 50, A357, as well as our newer developmental efforts, including castable 7xxx series aluminum, high strength aluminum (Nanophase) and oxygen-compatible alloys for advanced rocketry systems (Mondaloy). We’ve also designed and conducted significant testing at the metallurgical, component and sub-assembly and assembly level on a wide variety of hardware, spanning liquid rocket engines, terrestrial power, hypersonic vehicles and deep space applications.
Alloy Development and Metallurgical Design Support
Pratt & Whitney Rocketdyne are an industry leader and recognized expert at the joining of superalloys, as well as other advanced aerospace alloys. Whether it be welding or brazing, PWR has extensive experience with high temperature brazing, HIP/diffusion bonding, dissimilar metals welding and ASME code welding for aerospace and terrestrial energy applications. We have fully facilitized laboratories for rapid prototyping and process development for all types of joining operations, while still remaining flexible enough to handle production components.
The joining technology process focuses primarily on four specific processes: brazing, welding, plating and heat-treating. Brazing is a high temperature process by which two substrates, typically metallic but not always, are joined via a braze alloy in a furnace with tightly controlled heating and cooling rates. The key to brazing is that typically only the braze alloy melts, not the substrates, and upon cooling the opposing pieces are permanently joined. The welding processes at PWR include Tungsten Inert Gas (TIG), electron beam (EB), micro plasma transfer arc (MPTA), laser, and hydrogen torch welding. During the welding process, two materials are joined by either autogenously (no filler metal) or welding with filler metal. Welding differs from brazing in that the substrates are both melted during the joining process. Plating involves the electro-deposition of nickel, silver, or gold to facilitate the brazing process. Plating can also be implemented to create environmental barriers for substrate metals. Lastly, plating can also be used to provide structural integrity to hardware. Heat-treating is a thermal process by which the mechanical properties and physical nature of a material can be changed or tailored to meet a specific function. Heat-treating at PWR can be performed in an inert atmosphere, vacuum and hydrogen.