Ultrasonic Additive Manufacturing for Capillary Heat Transfer Devices and Integrated Heat Exchangers

Embedding three-dimensional heat exchangers as part of a multi-functional structure directly addresses the top priority goal described in the 2015 NASA Technology Roadmap TA12: Materials, Structures, Mechanical Systems, and Manufacturing. That top level goal is to: Develop materials to increase multi-functionality and reduce mass and cost (radiation protection/mass reduction challenges). Provide innovative designs and tools for robustness and superior structural integrity for deep space and science missions (reliability/ mass reduction challenges). Design and develop robust, long-life mechanisms capable of performing in the harsh environments (reliability challenge). Advance new processes and model-based manufacturing capabilities for more affordable and higher performance products (mass reduction/affordability challenge). Cube Sat components will have very small masses, and their temperatures are highly sensitive to variations in the component power output and spacecraft environmental temperature. The advanced thermal devices developed here will be capable of maintaining components within their specified temperature ranges, with excellent reliability of single piece structures, while concurrently minimizing added weight. The technology being developed in this effort directly addresses the two overarching themes of NASA's technology plan, critical attributes and technology themes required by every mission architecture: multifunctional and lightweight.

This program produces high performance heat exchangers embedded in structures with integrated temperature monitoring sensors. The embedded heat exchanger is part of a multifunctional three dimensional structure that will simultaneously accommodate thermal and mechanical loads, and offer radiation protection via multi-material laminates. Non-NASA commercial application of this technology has started with aerospace and defense companies who are already customers. These firms are early adopters of additive manufacturing because it enables lightweight designs and the production of parts with complex geometries. Additionally, aerospace and defense manufacturers frequently incorporate high value materials, and additive manufacturing allows them to maintain fine control of material properties and reduce raw material waste. There are very few additive approaches for fabricating metallic load-bearing structure with embedded multi-functional capability. Traditional fusion based welding and/or thermomechanical processes used for fabricating metallic structure would destroy delicate instruments. The solid-state nature of UAM is unique in that it preserves the strength of aerospace aluminum alloys, permits structures with dissimilar materials, and allows sensitive sensors, such as thermocouples, to be placed inside of metallic structure. More »