Abstract: A method is provided for refurbishing a C/C disk of a first thickness and coated with a first ceramic solution for a second life. The method includes machining the C/C disk of the first thickness to remove a coating of the first ceramic solution from the wear surfaces of the C/C disk of the first thickness. Removing the coating of the first ceramic solution further removes a portion of the C/C disk thereby forming a C/C disk of a second thickness. The second thickness is less than the first thickness. The method further includes coating the wear surfaces of the C/C disk of the second thickness with a second ceramic solution, thereby forming a C/C disk of the second thickness coated with the second ceramic solution. Additionally, the method includes drying the C/C disk of the second thickness coated with the second ceramic solution.

Abstract: A method is provided for forming a carbon/carbon (C/C) disk with boron nitride (BN) doping. Borazine is generated using a set of borazine precursors. Starting carbon fibers are coated or impregnated with the borazine in an inert atmosphere. The starting carbon fibers are needled into layered fabric and the layered fabric is needled into boards from which a preform is cut, the needling and cutting performed in the inert atmosphere. The borazine in the preform is stabilized to convert the borazine to polyborazylene. The polyborazylene in the preform is cured. The polyborazylene in the preform is then crystalized to form BN particulates. The preform with the BN particulates is carbonized and then densified with pyrolytic carbon.

Abstract: A pump assembly includes a cylinder block defining a piston bore therein extending in an axial direction. A sleeve lines the piston bore. A piston is included in the piston bore, configured to reciprocate along a stroke in the axial direction within the sleeve. A piston ring is engaged circumferentially about the piston. The piston ring is fixed to the piston and is slidingly engaged to an inner surface of the sleeve.

Abstract: A method is provided for decreasing a wear rate of a brake stack or a heat sink wear rate and increasing a brake life of the brake stack or the heat sink. The method includes coating a wear surface of a brake disk with at least one of an engineered ceramic material or ceramic solution, thereby forming a coated brake disk and installing the coated brake disk in a multi-disk brake system.

Abstract: In accordance with at least one aspect of this disclosure, a pump system for an aircraft includes, a cylinder barrel configured to rotate within a pump housing of a pump, and a plurality of pistons seated within a respective bore defined in the cylinder barrel. Each piston further includes a piston ring disposed at an end thereof configured to form a hydrodynamic seal with an inner surface of the respective bore. Each respective piston ring is of silicon nitride. In embodiments, the piston ring can include a chamfer on at least a leading edge of the piston ring. In embodiments, the piston ring can include a cut therethrough configured to allow for thermal expansion of the piston ring.

Abstract: In accordance with at least one aspect of this disclosure, a system includes, a cylinder barrel configured to rotate within a pump housing of a pump operatively connected to a driving member of the pump via a first shaft. A piston is seated within a bore defined in the cylinder barrel. The piston is operatively connected to the driving member of the pump via a second shaft. The first shaft and the second shaft each include a ball end configured to seat within the driving member. In embodiments, the ball end of at least the second shaft is of silicon nitride.

Abstract: In accordance with at least one aspect of this disclosure, a pump system for an aircraft includes, a cylinder barrel configured to rotate within a pump housing of a pump, and a plurality of pistons seated within a respective bore defined in the cylinder barrel. Each piston further includes a piston ring disposed at an end thereof configured to form a hydrodynamic seal with an inner surface of the respective bore. Each respective piston ring is of silicon nitride. In embodiments, the piston ring can include a chamfer on at least a leading edge of the piston ring. In embodiments, the piston ring can include a cut therethrough configured to allow for thermal expansion of the piston ring.

Abstract: In accordance with at least one aspect of this disclosure, a system includes, a cylinder barrel configured to rotate within a pump housing of a pump operatively connected to a driving member of the pump via a first shaft. A piston is seated within a bore defined in the cylinder barrel. The piston is operatively connected to the driving member of the pump via a second shaft. The first shaft and the second shaft each include a ball end configured to seat within the driving member. In embodiments, the ball end of at least the second shaft is of silicon nitride.

Abstract: In accordance with at least one aspect of this disclosure, a system comprises, a cylinder barrel configured to rotate within a pump housing. In embodiments, the cylinder barrel includes a main cylindrical body, a center recess defined within the main cylindrical body configured to seat a drive shaft therein, and a plurality of bores defined in the main cylindrical body, extending in an axial direction, wherein the plurality of bores are spaced apart circumferentially relative to one another about the main cylindrical body radially outward of the center recess. Each of the plurality of bores are configured to seat a respective piston therein and allow fluid flow therethrough. In embodiments, the main cylindrical body is of silicon nitride.