A component of a gas turbine engine comprises a substrate, a corrosion resistant top layer, and an intermediate corrodible layer disposed between the corrosion resistant top layer and the substrate. When corroding, the intermediate layer has a color contrasting with a color of the top layer. A method of detecting a crack when it penetrated the top layer in a component of a gas turbine engine having a corrosion resistant top layer and an intermediate corrodible layer comprises, in sequence, observing that at least one area of the component has a color contrasting with that of the top layer; determining that the color of the at least one area is a result of corrosion of the intermediate corrodible layer; and determining that the top layer has a crack as a result of determining corrosion of the intermediate layer. A method of facilitating crack detection in a component is also presented.

A blade outer airseal has a body comprising: an inner diameter (ID) surface; an outer diameter (OD) surface; a leading end; and a trailing end. The airseal body has a metallic substrate and a coating system atop the substrate along at least a portion of the inner diameter surface. At least over a first area of the inner diameter surface, the coating system comprises an abradable layer system comprising a plurality of layers including a relatively erosion-resistant first layer atop a relatively abradable second layer.

A blade outer airseal has a body comprising: an inner diameter (ID) surface; an outer diameter (OD) surface; a leading end; and a trailing end. The airseal body has a metallic substrate and a coating system atop the substrate along at least a portion of the inner diameter surface. At least over a first area of the inner diameter surface, the coating system comprises an abradable layer system comprising a plurality of layers including a relatively erosion-resistant first layer atop a relatively abradable second layer.

The present invention provides a hearth roll for heat treatment furnaces, which has excellent build-up resistance, has a hexavalent-chromium-free thermal spray coating film formed on the roll surface thereof and is safe for the environment. A method for manufacturing a hearth roll for continuous annealing furnaces includes a first step of applying an aqueous solution containing chromium phosphate onto a thermal spray coating film formed on the roll surface of a hearth roll or impregnating the thermal spray coating film with the aqueous solution; and a second step of burning the hearth roll.

A coated article is disclosed including a substrate, a bond coating, and a thermally insulating top coating. The substrate includes a substrate surface and a substrate material at the substrate surface. The bond coating is disposed on and contacts the substrate surface, and includes the substrate material and a bond coating surface distal from the substrate surface. The bond coating surface includes a greater surface roughness than the substrate surface. The thermally insulating top coating is disposed on and contacts the bond coating surface. A method for forming the coated article includes applying the bond coating to the substrate surface, and applying the thermally insulating top coating to the bond coating surface.

A coated article is disclosed including a substrate, a bond coating, and a thermally insulating top coating. The substrate includes a substrate surface and a substrate material at the substrate surface. The bond coating is disposed on and contacts the substrate surface, and includes the substrate material and a bond coating surface distal from the substrate surface. The bond coating surface includes a greater surface roughness than the substrate surface. The thermally insulating top coating is disposed on and contacts the bond coating surface. A method for forming the coated article includes applying the bond coating to the substrate surface, and applying the thermally insulating top coating to the bond coating surface.

A heat shielding coating (11) includes a bond coat layer (12) as a metal coupling layer laminated on a base material (10), and a top coat layer (13) which is laminated on the bond coat layer (12) and includes zirconia-based ceramic, in which the top coat layer (13) has a porosity of 9% or less.

At least one surface of a FRP component is coated by impregnating a structure formed with textile fibres with a flowable polymeric matrix material so the fibres are completely covered to form the coating, a thickness of the flowable polymeric matrix material above the fibres of at least 100 μm and at least one ply of pull-off fabric, mesh or gauze is laid on and wetted or impregnated completely with the flowable polymeric matrix material. The polymeric matrix material is cured then the at least one ply of pull-off fabric, mesh or gauze is removed by peeling and in this region a surface of increased roughness is obtained so between the surface of increased roughness and fibres there is a layer formed with the cured polymeric matrix material, having a thickness of at least 100 μm. Coating the increased roughness surface with a thermal spraying process.

A turbine part, such as a turbine blade or a distributor fin, for example, including a substrate made of superalloy based on monocrystalline nickel, including rhenium and/or ruthenium, and having a γ′-NisAI phase that is predominant by volume and a γ-Ni phase, the part also including a sublayer made of metal superalloy based on nickel covering the substrate, wherein the sublayer has a γ′-NisAI phase that is predominant by volume and wherein the sublayer has an average atomic fraction of aluminium of between 0.15 and 0.25, of chromium of between 0.03 and 0.08, of platinum of between 0.01 and 0.05, of hafnium of less than 0.01 and of silicon of less than 0.01. A process for manufacturing a turbine part including a step of vacuum deposition of a sublayer made of a superalloy based on nickel having predominantly by volume a γ′-NisAI phase, on a substrate made of superalloy based on nickel including rhenium and/or ruthenium.

A turbine part, such as a turbine blade or a distributor fin, for example, including a substrate made of superalloy based on monocrystalline nickel, including rhenium and/or ruthenium, and having a γ′-NisAI phase that is predominant by volume and a γ-Ni phase, the part also including a sublayer made of metal superalloy based on nickel covering the substrate, wherein the sublayer has a γ′-NisAI phase that is predominant by volume and wherein the sublayer has an average atomic fraction of aluminium of between 0.15 and 0.25, of chromium of between 0.03 and 0.08, of platinum of between 0.01 and 0.05, of hafnium of less than 0.01 and of silicon of less than 0.01. A process for manufacturing a turbine part including a step of vacuum deposition of a sublayer made of a superalloy based on nickel having predominantly by volume a γ′-NisAI phase, on a substrate made of superalloy based on nickel including rhenium and/or ruthenium.