APPLIED TUNGSTENITE CORP — National Aeronautics and Space Administration SBIR Phase I: S4

Description

This SBIR Phase I will formulate and test a metal/WS2 Composite Dry Film Lubricant.The variables which will affect the result are the carrier gas temperature, the impact velocity on the substrate and the ratio of WS2 to metal.Three different metals are being explored to increase chances of success. Harder, higher melting point metals like Ti64 are more challenging for the Cold Spray technique, but if successful, could be extremely useful because of the extensive use of Ti64 on spacecraft. Al2024 is less hard with a lower melting point, and so is more likely to work, and also has some application on spacecraft. Using copper will ensure success of the technique, and its hardness is greater than that of WS2 alone. In addition, all three will be evaluated as to the best coating for stainless steel surfaces like 440C.In addition to friction and wear in sliding contact, abrasion testing will be conducted to evaluate which of the three composite coatings are more resistant to the potentially hard abrasive materials to be encountered on planet surfaces.We expect greatly increased durability over other Dry Film Lubricants because wear of the composites will result in burnishing a thin, pure, low friction film of WS2 on top of the hard, wear resistant substrate. This proposed metal/WS2 coating will create self-lubricating parts that with continued sliding contact will continually create a thin low friction layer on the surface.At the end of this Phase I program, we anticipate having successfully grown various compositions of each of the three composite types on test samples, and evaluated their friction and wear properties using pin-on-disk testing in an inert atmosphere (to model space and planet environments). Abrasion testing will be done to evaluate the coatingsrsquo; resistance to harsh particulate-filled environments. Thickness and composition testing will be done to correlate the coatings properties with performance.