A method of making an aircraft blade is provided. The method comprises the steps of: assembling two or more fibre-reinforced thermoplastic composite parts into a blade assembly; and welding the fibre-reinforced thermoplastic composite parts together utilising an additional thermoplastic located at least at locations where the parts will abut when assembled. The additional thermoplastic has a melting or softening temperature lower than a melting temperature of each of the fibre-reinforced thermoplastic composite parts being assembled. The step of welding comprises heating the blade assembly to a temperature above the melting/softening temperature of the additional thermoplastic and below the melting temperature of each of the fibre-reinforced thermoplastic composite parts so as to melt/soften the additional thermoplastic and thereby weld the fibre-reinforced thermoplastic composite parts together to form the aircraft blade.

A structure which is resistant to corrosion at high temperatures comprises a layer of ruthenium and/or ruthenium alloy and a layer of a refractory metal having a high strength at high temperatures, such as rhenium. Further, the structure may include a layer of ceramic such as zirconia or hafnia on the exposed face of the ruthenium layer. Alternative embodiments of the present invention include a catalyst formed from a low strength support structure with a first metal layer and a second ruthenium catalytic layer on top of the first metal layer. Another alternative embodiment of the present invention includes the formation of high purity ruthenium electrodes that are resistant to corrosion at high temperatures.

A turbomachine includes a shroud and a rotor, which includes first and second blades. A first blade tip and a second blade tip respectively include a base and a first layer. The second blade tip also includes an abrasive second layer layered over the respective first layer. The first layer has a lower material hardness than the shroud. The second layer has a lower thermal stability than the shroud and the first layer. The rotor performs a grind operation and, subsequently, a post-grind operation. The second layer, in the grind operation, contacts and removes material from the shroud, and wears away, thereby revealing the first layer of the second blade tip for the post-grind operation. The first layer of the first blade tip is spaced apart with at least some radial clearance from the shroud in the grind and post-grind operations.

A case clearance control system comprising a blade outer air seal support structure having a plurality of protrusions extending radially from the blade outer air seal support structure opposite a blade outer air seal proximate the blade outer air seal support structure; a thermal control ring coupled to the blade outer air seal support structure, the thermal control ring including a plurality of receivers configured to couple with the plurality of protrusions; a thermal break formed between the plurality of protrusions and the plurality of receivers, the thermal break configured to control heat transfer between the blade outer air seal support structure and the thermal control ring; and a plurality of flow passages formed between the blade outer air seal support structure, the thermal control ring and the plurality of protrusions, the plurality of flow passages configured to allow cooling air flow to condition the thermal control ring and maintain thermal control ring dimensions.

An article includes a substrate and a barrier layer on the substrate. The barrier layer includes a matrix, diffusive particles dispersed in the matrix, and gettering particles dispersed in the matrix. The gettering particles include at least one alloyed metal silicide. A composite material and a method of fabricating an article are also disclosed.

A component of a rotor system is provided and includes a disk and a reinforcing ring. The disk includes an airfoil element, a web extending radially inwardly from the airfoil element and an arm element extending axially from the web. The reinforcing ring is formed of fiber reinforced materials and is disposed to fit about the arm element.

A component of a rotor system is provided and includes a disk and a reinforcing ring. The disk includes an airfoil element, a web extending radially inwardly from the airfoil element and an arm element extending axially from the web. The reinforcing ring is formed of fiber reinforced materials and is disposed to fit about the arm element.

A case clearance control system comprising a blade outer air seal support structure having a plurality of protrusions extending radially from the blade outer air seal support structure opposite a blade outer air seal proximate the blade outer air seal support structure; a thermal control ring coupled to the blade outer air seal support structure, the thermal control ring including a plurality of receivers configured to couple with the plurality of protrusions; a thermal break formed between the plurality of protrusions and the plurality of receivers, the thermal break configured to control heat transfer between the blade outer air seal support structure and the thermal control ring; and a plurality of flow passages formed between the blade outer air seal support structure, the thermal control ring and the plurality of protrusions, the plurality of flow passages configured to allow cooling air flow to condition the thermal control ring and maintain thermal control ring dimensions.

A drag pump for pumping gas and a set of vacuum pumps including the drag pump are disclosed. The drag pump comprises: a rotor configured to rotate within a stator component and to drive a gas to be pumped from a gas inlet to a gas outlet; magnetic bearings for rotatably mounting the rotor within the pump; wherein at least a portion of the rotor and stator component configured to contact the gas to be pumped are configured for operation at temperatures above 130° C.

An article for high temperature service is presented. The article includes a substrate and a plurality of coatings disposed on the substrate. At least one coating in the plurality of coatings includes an oxide of nominal composition A.sub.xB.sub.1-yD.sub.yO.sub.z, wherein A includes a rare-earth element, B includes tantalum or niobium, D includes zirconium or hafnium, 2≤x≤3, 0<y<1, and 6≤z≤7.