Abstract:
System and method are provided for processing inspection data for evaluating degradation of a coating, as may be used as a thermal barrier in a gas turbine component. The system may include a database (12) with a representation of a component divided into zones (16, 18) corresponding to a performance criteria associated with the operation of the component. The system may further include a processor (20) configured to process inspection data for the coating relative to the zones, such as calculating an area percentage of coating degradation for each zone. A rule base may be used to correlate the processed inspection data with appropriate repair options.
Abstract:
A multi-layer thermal barrier coating (12) having a porous first layer of ceramic insulating material (20) and a second relatively dense layer of ceramic insulating material (22) having a plurality generally vertical gaps (26) formed therein. The porous conventional as-deposited APS microstructure of the first layer provides thermal and chemical protection for the substrate, while the gaps of the columnar-grained second layer provide thermal shock resistance for the coating. An air plasma spray process may be used to deposit both the first and the second layers of material, as well as any underlying bond coat layer. The gaps of the columnar-grained second layer do not extend into the first layer. The pores (28) of the first layer function as crack-arrestors for cracks initiating at the gaps of the second layer.
Abstract:
A circuit assembly (34) resistant to high-temperature and high g centrifugal force is disclosed. A printed circuit board (42) is first fabricated from alumina and has conductive traces of said circuit formed thereon by the use of a thick film gold paste. Active and passive components of the circuit assembly are attached to the printed circuit board by means of gold powder diffused under high temperature. Gold wire is used for bonding between the circuit traces and the active components in order to complete the circuit assembly (34). Also, a method for manufacturing a circuit assembly resistant to elevated temperature is disclosed.
Abstract:
In a telemetry system for use in an engine, a circuit structure (34) affixed to a moving part (20) of the engine is disposed for amplifying information sensed about a condition of the part and transmitting the sensed information to a receiver external to the engine. The circuit structure is adapted for the high temperature environment of the engine and includes a differential amplifier (102, 111) having an input for receiving a signal from a sensor (101, 110) disposed on the part. A voltage controlled oscillator (104, 115) with an input coupled to the output of the amplifier produces an oscillatory signal having a frequency representative of the sensed condition. A buffer (105, 116) with an input coupled to the output of the oscillator buffers the oscillatory signal, which is then coupled to an antenna (26) for transmitting the information to the receiver.
Abstract:
The present invention relates to an aqueous polyurethane coating composition comprising: 1) 1 to 99 wt. % of the reaction product of: a) a polyol component, which is soluble or dispersible in water and is the reaction product of a polyisocyanate component containing 50 to 100 wt. % of an aliphatic diisocyanate, a polyol component containing one or more polyether polyols and having an OH number of 25 to 350 mg KOH/g solids and an isocyanate-reactive component containing at least one group capable of salt formation; and b) polyisocyanate component, which is soluble or dispersible in water, has blocked isocyanate groups and is the reaction product of one or more polyisocyanates having an isocyanurate group content of 0 to 30 wt. %, a reversible, monofunctional blocking agent for isocyanate groups, a nonionic hydrophilic component and a stabilizing component which has 1 to 2 hydrazide groups and a molecular weight of 74 to 300 g/mol; and 2) 1 to 99 wt. % of an aqueous polyurethane dispersion prepared from at least one polycarbonate polyol, wherein the total wt. % of components 1) and 2) add up to 100%.
Abstract:
A layer system is disclosed. The layer system includes a substrate and a ceramic outer layer. The ceramic outer ceramic layer is produced from a ceramic powder. The ceramic powder include a phrochlore phase according to the empirical formula AxByOz with x, y≈2, z≈7 and a secondary oxide CrOs with r, s>0.
Abstract:
There is described a ceramic powder, ceramic layer and layer system having gadolinium/mixed crystal pyrochlore phases and oxides. Besides a good thermal insulation property, thermal insulation layer systems must also have a long lifetime of the thermal insulation layer. The layer system according to the invention has an outer ceramic layer, which comprises a mixed crystal of gadolinium zirconate and gadolinium hafnate.
Abstract:
A circuit affixed to a moving part of an engine for sensing and processing the temperature of the part. The circuit generates a signal representative of the temperature sensed by a thermocouple (110) and amplified by an amplifier (112). A square wave oscillator (113) with a temperature sensitive capacitor (C8) varies its frequency in response to changes of a local temperature of the circuit. A chopper (114, J27) converts the output of the amplifier into an alternating current signal. The chopper is gated by the square wave oscillator and a second input is coupled to an output of the amplifier. Thus, the chopper has an output signal having a frequency representative of the local temperature and an amplitude representative of the thermocouple temperature, whereby the combined signals represent the true temperature of the part.
Abstract:
A circuit assembly (34) resistant to high-temperature and high g centrifugal force is disclosed. A printed circuit board (42) is first fabricated from alumina and has conductive traces of said circuit formed thereon by the use of a thick film gold paste. Active and passive components of the circuit assembly are attached to the printed circuit board by means of gold powder diffused under high temperature. Gold wire is used for bonding between the circuit traces and the active components in order to complete the circuit assembly (34). Also, a method for manufacturing a circuit assembly resistant to elevated temperature is disclosed.
Abstract:
A thermal barrier coating system is provided. The thermal barrier coating system may include a first layer of ceramic insulating material (21) (see FIG. 1) disposed on a substrate surface. The thermal barrier coating system may also include a second layer of ceramic insulating material (25) disposed on the first layer of ceramic insulating material. The second layer of ceramic insulating material may include one or more crack arrestors therein. A third layer of ceramic insulating material (26) is disposed on the second layer of ceramic insulating material. The third layer may be configured as a sacrificial layer to absorb mechanical shock generated in the event of a foreign object collision with the third layer. The one or more crack arrestors in the second layer can avoid propagation towards the first layer of one or more cracks that can form in the event of the foreign object collision with the third layer.