Open Competition 3 - Chemistry and Materials

Mechanical Patterning of Nanostructured Foils for Reactive Joining: Enhancing Stability with Novel Processing and Nanoengineering

Sponsor: Reactive NanoTechnologies, Inc.

• Project Performance Period: 10/1/2003 - 3/31/2006
• Total project (est.): $2,767,884.00
• Requested ATP funds: $1,900,000.00

During reactive foil joining, two components are sandwiched and pressed around a reactive foil and two adjacent layers of solder. Activating a self-propagating reaction within the foil heats the surrounding solder layers to their melting point and thereby joins the components in less than one second. The highly localized heating in this process enables the joining of temperature sensitive components, such as microelectronic devices, as well as dissimilar materials, such as metals and ceramics. However, the instability (tendency to ignite inadvertently) of reactive foils prevents their extensive use. Reactive NanoTechnologies (RNT) will develop a new class of reactive foils that are stable enough to allow patterning by mechanical punching and stamping, and promise substantial gains in productivity for U.S. manufacturers. Foils consisting of hundreds of alternating nanoscale layers will be fabricated to offer different heats of reaction, using different pairs of elements or compounds, such as nickel with aluminum, titanium with silicon or carbon, and aluminum with ferrous or copper oxides. To achieve foil stability, RNT will explore integrating microscale layers of solder into the foils, annealing the foils, and separating each nanoscale layer with an inert material, such as copper. Improved foil stability will allow RNT to fabricate foils in large sheets and manufacturers to cut the sheets efficiently into patterns for particular applications. Because the standard patterning techniques of punching and stamping could cause ignition, the main technical risk of this two-year project lies in making foils that are stable enough to withstand patterning yet chemically reactive enough to form strong joints. Private investment funds are insufficient to support an accelerated pace of research. ATP funding will accelerate the development of highly stable foils and advance commercialization by approximately four years. The market for RNT's joining technology is estimated to be $12 billion annually. The rapidity and lower cost of reactive joining should produce substantial gains in productivity. Instant, high-quality bonding should prove especially useful in microelectronics and fiber optics. In aerospace, reactive joining could replace riveting, a known source of potential structural weakness. Because this technology can join ceramics to metals, RNT's new foils could lead to lighter automobile engines and could stimulate use of lightweight ceramics for armor on tanks and other vehicles.

For project information:

Michael Choi, (410) 771-9801
mchoi@rntfoil.com

ATP Project Manager

H. Felix Wu, (301) 975-4685
felix.wu@nist.gov