Improved tribological coatings for gas turbine brush seals

Brush seals have the potential to greatly reduce parasitic leakage at critical location in gas turbines. Presen brush seals are expensive and do experience seal and bristle wear especially at high operating temperatures. Implant Sciences proposes to develop and test new hard coatings for the reduction of seal wear. These new coatings consisting of amorphous diamond and silicon carbide will be applied by a new lower-cost fabrication technique utilizing a filtered cathodic arc system. The coatings will be evaluated with respect to friction and wear using a pin-on-disk test rig which will be modified to operate at 750 degrees C and surface speeds up to 900 ft/sec. Cyclic oxidation tests will also be performed on coated rotor material.