Original Date: 03/08/1999
Revision Date: 01/18/2007

Williams International machines the compressor section of the Tomahawk F107 engine from a titanium forging. In 1996, the company approached The Applied Research Laboratory at the Pennsylvania State University (ARL Penn State) about developing a tool which could machine titanium and last two-fold longer than commercially available tools. Due to wear, only a quarter section of the titanium could be processed before tool replacement was necessary. This additional operation proved to be costly and time consuming. To resolve this issue, the ARL Penn State developed a nanograined material for the manufacture and coating of cutting tools used for machining/milling titanium.

In developing nanoparticle fabrication of tools, the ARL Penn State faced various obstacles such as the difficulty of machining titanium, poor tool life, reaction to tool, inadequate dimensional control, and poor thermal conductivity. Of the eight coating materials considered by the ARL Penn State, titanium-aluminum-nitride proved the best. The laboratory is also consolidating nanocrystalline powders via rapid solid-state techniques (e.g., rapid hot pressing, microwave sintering exotherms) rather than the current practice of using liquid-phase sintering.

By processing and applying nanophase powders to cutting tools, the ARL Penn State increased tool life by two-fold. This method reduces fabrication costs of F107 compressors by 50% or $480,000 per year. In addition, the increased tool longevity will reduce the number of tool changes and improve adherence to manufacturing tolerances. Other applications for these tools include the machining of F119 engines, Joint Strike Fighter engines, and Advanced Amphibious Assault Vehicle (AAAV) hatch covers.

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