Layered-Lattice Oxides for Lubrication at 1000 Degrees Celsius

It is well established that certain compounds having layered lattice structure, like molybdenum disulfide, are effective solid lubricants. Since a number of double oxides, stable at 1000@C, have this layered structure it is proposed to evaluate their potential as high temperature solid lubricants. A selection will be made, based on a literature review, of 10 compounds which represent different classes of layered structures with emphasis on the BasTa4O15 structure. These compounds will be prepared, characterized and evaluated. Friction tests will be run at various temperature levels up to 1000@C and "corrosion" compatibility tests will be run at 1000@C using various substrates. If necessary, additives will be used to improve their performance. New compounds with friction coefficients in the 0.2 to 0.25 range will be applied to refractory metals or ceramic composite substrates and tested to 1200@C to demonstrate their applicability for NASA High Speed Civil Transport Applications.