摘要:
Methods and apparatus to make multilayer thermal barrier coatings for superalloy substrates such as turbine blades or vanes are disclosed. The methods produce non-homogeneous, nanometer-size, successive layers and a non-homogeneous interfacial layer without the use of baffles. Methods are also disclosed to use a lower cost metallic source and an oxygen bleed to create alumina or tantalum oxide vapor, to use a tantalum oxide or an alumina ingot and a low pressure inert gas feed to direct the vapor clouds, to use pulsed evaporation from a secondary vapor source to create non-homogeneous multilayer coating on non-rotated substrates, to use an electric bias to direct the vapor clouds, and to use a mechanical system to direct the vapor clouds or move and position the article to be coated in the clouds.
摘要:
A turbine engine component includes an electron beam-physical vapor deposition thermal barrier coating covering at least a portion of a substrate. The thermal barrier coating includes an inner layer having a columnar-grained microstructure with inter-columnar gap porosity. The inner layer includes a stabilized ceramic material. The thermal barrier coating also includes a substantially non-porous outer layer, covering the inner layer and including the stabilized ceramic material. The outer layer is deposited with continuous line-of-sight exposure to the vapor source under oxygen deficient conditions. The outer layer may further comprise a dopant oxide that is more readily reducible than the stabilized ceramic material. During deposition, the outer layer may also have an oxygen deficient stoichiometry with respect to the inner layer. Oxygen stoichiometry in the outer layer may be restored by exposure of the coated component to an oxidizing environment.
摘要:
A turbine blade tip and shroud clearance control coating system comprising an abrasive blade tip coating and an abradable shroud coating are provided. The abrasive layer may comprise abrasive particles of cubic zirconia, cubic hafnia or mixtures thereof, and the abradable layer may be a nanolaminate thermal barrier coating that is softer than the abrasive layer. The invention further provides an alternate coating system comprising an abradable blade tip coating and an abrasive shroud coating.
摘要:
A durable protective coating may be formed by applying a thin layer of metastable alumina to a bond coating on a substrate. A thermal barrier coating may then be applied to the metastable alumina and the resulting part may be heat treated to transform the metastable alumina to a mixed alpha alumina having particles of the thermal barrier coating, such as zirconia in the case of an yttria stabilized zirconia thermal barrier coating, dispersed therein. The resulting thermal barrier coating may inhibit microbuckling of the thermally grown oxide scale that grows over time at the thermal barrier coating-bond coating interface.
摘要:
A thermal barrier coating for superalloy articles such as turbine engine vanes and blades that are exposed to high temperature gas is disclosed. The coating includes a columnar grained ceramic layer applied to an aluminide or MCrAlY bond coat by electron beam physical vapor deposition. The ceramic layer is comprised a plurality of layers of zirconia stabilized with 20 percent yttria and the interfaces between the layers are decorated with particles selected from a group consisting of Ta2O5 and alumina. Though not essential to the invention a layer of tetragonal zirconia may be deposited both under and over the ceramic coat. An improved electron physical beam vapor deposition process for applying this ceramic layer is also disclosed.
摘要:
A thermal barrier coating for superalloy turbine engine vanes and blades that are exposed to high temperature gas is disclosed. The coating includes an aluminide or MCrAlY layer, an alumina layer, and a ceramic top layer. The ceramic layer has a columnar grain microstructure. A bond inhibitor is disposed in the gaps between the columnar grains. This inhibitor is preferably alumina.
摘要:
A coating for spark plugs and engine parts is resistant to fouling. The coating may be applied to the spark plug or engine part by dipping the part in a sol gel solution, ensuring it wets the part, and extracting it at a slow, controlled rate. As the part is allowed to dry, the sol gel reacts with moisture in the air to form a thin oxide film. Unlike conventional sol gel applications, which apply the oxide directly to the part, the present invention may form an oxide coating, in situ, while drying in place on the part.
摘要:
Protective coating systems for gas turbine engine applications and methods for fabricating such protective coating systems are provided. An exemplary protective coating system comprises an aluminide-comprising bond coating disposed on a substrate, a thermal barrier coating overlying the aluminide-comprising bond coating, and a silicate layer interposed between the thermal barrier coating and the aluminide-comprising bond coating.
摘要:
The present invention thus provides an improved method for coating turbine engine components. The method utilizes a cold high velocity gas spray technique to coat turbine blades, compressor blades, impellers, blisks, and other turbine engine components. These methods can be used to coat a variety of surfaces thereon, thus improving the overall durability, reliability and performance of the turbine engine itself. The method includes the deposition of powders of alloys of nickel and aluminum wherein the powders are formed so as to have an amorphous microstructure. Layers of the alloys may be deposited and built up by cold high velocity gas spraying. The coated items displayed improved characteristics such as hardness, strength, and corrosion resistance.
摘要:
The present invention provides methods and materials for use in applying a coating on a surface of a magnesium component. The method includes the steps of: accelerating a coating powder to a velocity of between about 500 to about 1200 meters/second, wherein the coating powder comprises a material selected from the group consisting of aluminum, aluminum alloys, titanium, titanium alloys, and composites; directing the coating powder through a convergent-divergent nozzle onto the surface of the magnesium component; and forming a coating on the surface of the magnesium component so as to substantially cover the surface of the magnesium component. The coating thickness may be between approximately 0.1 to approximately 1.0 mm.