Abstract: This disclosure is directed to seal assemblies for a turbomachine. The seal assemblies include stationary and rotating components and at least one interface between the stationary and rotating components. The seal assembly further includes a self-lubricating lattice element made of carbon or a carbon-based material. The self-lubricating lattice element may have a porous and compressible microstructure capable of retaining a liquid substance. During engine operation, the self-lubricating lattice element can compress and expel some portion of the liquid substance to form a liquid-containing layer between the rotating and stationary components of the seal assembly. Also described herein are self-lubricating wear sleeves for use in other portions of the turbomachine.

Abstract: A high entropy alloy-based composition is provided that has the formula: (M1aM2bM3cM4dM5eM6f)CrAlY1-x-zZrxMoz where: each of M1, M2, M3, M4, M5, and M6 is a different alloying element selected from the group consisting of Ni, Co, Fe, Si, Mn, and Cu such that none of M1, M2, M3, M4, M5, and M6 are the same alloying element; 0.05?a?0.35; 0.05?b?0.35; 0.05?c?0.35; 0.05?d?0.35; 0.05?e?0.35; 0?f?0.35; a+b+c+d+e+f=1; 0?x?1; 0?z?1; and 0?x+z?1.

Abstract: Systems and methods for measuring the clearance gaps between rotating and stationary components of a turbomachine are provided. In one exemplary aspect, flexible and degradable sensing arrays that include a plurality of microwave sensors are utilized to sense the clearance gaps between rotating and stationary components of the turbomachine. Microwaves generated by a microwave generator are transmitted to the sensors. Upon rotation of the rotating components, the rotating components reflect the microwaves transmitted thereto. The microwave sensors capture the transmitted signal and also capture a reflected signal indicative of the transmitted signal reflected by the rotating components. The signals are then forwarded to a computing device for processing. The amplitude difference at the interference fringes between the superimposed signals is representative of the clearance gaps between the rotating and stationary components.

Abstract: A silicone bond coat composition having a viscosity of less than 1,600 centistokes is applied to substantially all external surfaces of the article and then cured. A liquid silicone elastomer outer coat composition comprising a high viscosity first liquid silicone elastomer formulation and a low viscosity second liquid silicone elastomer formulation is then applied and cured to provide a protected article having a complex shape. Optimal coatings result from a careful balancing of component viscosities. In an embodiment, the first formulation has a viscosity greater than 300,000 centistokes, and the second formulation has a viscosity less than 6,000 centistokes, and the liquid silicone elastomer outer coat composition comprises from about 60 to about 40 percent by weight of the first formulation and from about 40 to about 60 percent by weight of the second liquid silicone elastomer formulation.

Abstract: Systems and methods for measuring the clearance gaps between rotating and stationary components of a turbomachine are provided. In one exemplary aspect, flexible and degradable sensing arrays that include a plurality of microwave sensors are utilized to sense the clearance gaps between rotating and stationary components of the turbomachine. Microwaves generated by a microwave generator are transmitted to the sensors. Upon rotation of the rotating components, the rotating components reflect the microwaves transmitted thereto. The microwave sensors capture the transmitted signal and also capture a reflected signal indicative of the transmitted signal reflected by the rotating components. The signals are then forwarded to a computing device for processing. The amplitude difference at the interference fringes between the superimposed signals is representative of the clearance gaps between the rotating and stationary components.

Abstract: A method for repairing a Ni-based alloy component includes preparing a surface of the Ni-based alloy component for receiving a cold spray repair; spraying a stream of particles onto a the surface of the Ni-based alloy component to form a coating thereon; and removing any over-spray on the surface of the Ni-based alloy component. The particles are formed from an alloy material having a melting point such that the particles are sprayed at a spray temperature that is less than the melting point of the alloy material.

Abstract: A method for repairing a Ni-based alloy component is prepared. The method may include preparing a surface of the Ni-based alloy component for receiving a cold spray repair; spraying a stream of particles onto a the surface of the Ni-based alloy component to form a coating thereon; and removing any over-spray on the surface of the Ni-based alloy component. The particles may be formed from an alloy material having a melting point such that the particles are sprayed at a spray temperature that is less than the melting point of the alloy material.

Abstract: A circuit breaker having a monolithic structure and method of making is disclosed. The monolithic structure includes an arm portion having copper and a contact portion having a composite material. The composite material has a metallic matrix and a second phase disposed in the metallic matrix. The method of making the monolithic structure includes introducing a first powder into a first region of a mold, introducing a second powder into a second region of the mold, and consolidating the first powder and the second powder together. The first region of the mold corresponds to a contact portion, and the second region corresponds to an arm portion of the monolithic structure of the circuit breaker.

Abstract: A silicone bond coat composition having a viscosity of less than 1,600 centistokes is applied to substantially all external surfaces of the article and then cured. A liquid silicone elastomer outer coat composition comprising a high viscosity first liquid silicone elastomer formulation and a low viscosity second liquid silicone elastomer formulation is then applied and cured to provide a protected article having a complex shape. Optimal coatings result from a careful balancing of component viscosities. In an embodiment, the first formulation has a viscosity greater than 300,000 centistokes, and the second formulation has a viscosity less than 6,000 centistokes, and the liquid silicone elastomer outer coat composition comprises from about 60 to about 40 percent by weight of the first formulation and from about 40 to about 60 percent by weight of the second liquid silicone elastomer formulation.

Abstract: A circuit breaker having a monolithic structure and method of making is disclosed. The monolithic structure includes an arm portion having copper and a contact portion having a composite material. The composite material has a metallic matrix and a second phase disposed in the metallic matrix. The method of making the monolithic structure includes introducing a first powder into a first region of a mold, introducing a second powder into a second region of the mold, and consolidating the first powder and the second powder together. The first region of the mold corresponds to a contact portion, and the second region corresponds to an arm portion of the monolithic structure of the circuit breaker.

Abstract: A method is provided that includes providing a resin in liquid form. The resin can be partially cured, and subsequent to partially curing the resin, the resin can be mixed with filler particles. The resin and filler particles can be mixed, say, in a planetary mixer, and can be exposed to an ambient pressure less than atmospheric pressure during mixing. Subsequent to mixing the resin and filler particles, the resin can be fully cured. The fully-cured resin can be disposed between first and second conductive components configured to be maintained at different potentials, such as between a phase conductor and a ground conductor.

Abstract: A composition for a wear-resistant and low-friction coating is presented. The coating composition includes a hard ceramic phase, a metallic binder phase and a lubricant phase. The lubricant phase includes a multi-component oxide. An article having a wear-resistant and low-friction coating and a method of making such a coating are also described.

Abstract: A method is provided that includes providing a resin in liquid form. The resin can be partially cured, and subsequent to partially curing the resin, the resin can be mixed with filler particles. The resin and filler particles can be mixed, say, in a planetary mixer, and can be exposed to an ambient pressure less than atmospheric pressure during mixing. Subsequent to mixing the resin and filler particles, the resin can be fully cured. The fully-cured resin can be disposed between first and second conductive components configured to be maintained at different potentials, such as between a phase conductor and a ground conductor.