摘要:
Components and methods of forming a protective coating system on the components are provided. In an embodiment, and by way of example only, the component includes a ceramic substrate and a braze layer disposed over the ceramic substrate. The braze layer includes a silicon matrix having a first constituent and a second constituent that is different than the first constituent. The first constituent forms a first intermetallic with a portion of the silicon matrix and the second constituent forms a second intermetallic with another portion of the silicon matrix, wherein the braze layer is formulated to provide a barrier to oxygen diffusion therethrough.
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 turbine blade tip and shroud clearance control coating system comprising a dense abrasive blade tip layer and an abradable shroud layer are provided. The dense abrasive coating may comprise cubic zirconia, hafnia or mixtures thereof and the abradable layer may be a nanolaminate thermal barrier coating that is softer than the dense abrasive layer.
摘要:
A protective barrier coating system including a diffusion barrier coating and an oxidation barrier coating and method for use in protecting silicon-based ceramic turbine engine components. A complete barrier coating system includes a thermal barrier coating of stabilized zirconia and an environmental barrier coating of an alloyed tantalum oxide. The oxidation barrier coating includes a layer of metallic silicates formed on a substrate of silicon nitride or silicon carbide to be protected. The oxidation barrier coating can include silicates of scandium, ytterbia or yttrium. The oxidation barrier coating may also include an inner layer of Si2ON2 between the diffusion barrier and the metallic silicate layer. The oxidation barrier coating can be applied to the substrate by spraying, slurry dipping and sintering, by a sol-gel process followed by sintering, by plasma spray, or by electron beam-physical vapor deposition. The diffusion layer of essentially pure Si3N4 can be applied to the substrate to prevent the migration of damaging cations from the protective layers to the substrate and is preferably formed by chemical vapor deposition. A method for protecting silicon based substrates can comprise a step of forming an oxidation barrier coating on a substrate, where a step of forming the oxidation barrier includes a step of sintering the oxidation barrier and substrate in a wet gas containing hydrogen.
摘要翻译:一种包括扩散阻挡涂层和氧化屏障涂层的保护性屏障涂层系统以及用于保护硅基陶瓷涡轮发动机部件的方法。 完整的阻隔涂层系统包括稳定的氧化锆的隔热涂层和合金化氧化钽的环境屏障涂层。 氧化阻挡涂层包括在待保护的氮化硅或碳化硅的衬底上形成的金属硅酸盐层。 氧化屏障涂层可以包括钪,镱或钇的硅酸盐。 氧化阻隔涂层还可以包括扩散阻挡层和金属硅酸盐层之间的Si 2 2 2 N 2的内层。 通过喷雾,浆料浸渍和烧结,通过溶胶 - 凝胶法烧结,通过等离子体喷涂,或通过电子束 - 物理气相沉积,可将氧化阻隔涂层施加到基材上。 可以将基本上纯的Si 3 N 4 N 4的扩散层施加到基底上,以防止损伤的阳离子从保护层迁移到基底,并且优选地由化学 气相沉积。 用于保护硅基基板的方法可以包括在基板上形成氧化阻挡涂层的步骤,其中形成氧化屏障的步骤包括在含氢的湿气中烧结氧化阻挡层和基板的步骤。
摘要:
A component comprising a silicon-based substrate and a diffusion barrier coating disposed on the silicon-based substrate. The diffusion barrier coating comprises an isolation layer disposed directly on the silicon-based substrate and at least one oxygen barrier layer disposed on the isolation layer. The oxygen barrier layer prevents the diffusion of oxygen therethrough, and prevents excessive oxidation of the silicon-based substrate. The isolation layer(s) prevent contaminants and impurities from reacting with the oxygen barrier layer. An environmental barrier coating may be disposed on the diffusion barrier coating, and a thermal barrier coating may be disposed on the environmental barrier coating. Methods for making a component having a diffusion barrier coating are also disclosed.
摘要:
A thermal barrier coating for nickel based 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 a platinum modified Ni3Al gamma prime phase bond coat having a high purity alumina scale. The preferred composition of the bond coat is 5 to 16% by weight of aluminum, 5 to 25% by weight of platinum with the balance, at least 50% by weight, nickel. A method for making the bond coat is also disclosed.
摘要:
An article having a thermal barrier coating includes a superalloy substrate having a columnar grained ceramic coat formed thereon. The ceramic coat includes a nanolaminate region comprising repeating layers of ceramic material with each layer being less than 500 nm in thickness, with dispersions of metal oxide doping material situated between each of the layers. The ceramic coat further includes a non-doped region having a thickness greater than 500 nm adjacent to the nanolaminate region, the non-doped region including one layer or a plurality of adjacent layers of ceramic material without dispersions of metal oxide doping material situated between each of the layers. In one embodiment, and by way of example only, a bond coat is formed between the substrate and the columnar grained ceramic coat. According to another embodiment, the superalloy substrate forms an adherent alumina scale, and no bond coat is necessary.
摘要:
Exemplary embodiments of the invention provide barrier coated substrates and methods of coating a substrate with a barrier coating derived from sol gels. An example includes a barrier coated aerospace component that is subject to hot salt corrosion during use. The barrier coating is derived from oxidation of a coating composition that includes at least one sol gel. The barrier coating resists hot salt corrosion for an incubation period of such duration that an uncoated superalloy substrate under the same conditions would suffer corrosion to a depth of about 2.0 mils. Methods of applying the barrier coating include the steps of selecting a first liquid sol gel and wetting surfaces of the superalloy substrate with the selected first liquid sol gel. The wetted surfaces of the superalloy substrate are subjected to heat treatment. The heat treatment includes sintering of sol gel to oxide to produce a barrier coating.
摘要:
An electrolyte for use in electrolytic platinum platinum plating that results in reduced Cl, S, or P contaminant production. The bath comprises 0.01 to 320 g/lit of platinum in the form of the platinum salt dinitrodiammine platinum, Pt(NH3)2(NO2)2 or variants thereof and 0.1 to 240 g/lit of alkali metal carbonate M2CO3 or bicarbonate MHCO3 where M is selected from a group comprising lithium (Li), sodium (Na), potassium (K), rubidium (Rb) and cesium (Cs).
摘要:
Components and methods of forming a protective coating system on the components are provided. In an embodiment, and by way of example only, the component includes a ceramic substrate and a braze layer disposed over the ceramic substrate. The braze layer includes a silicon matrix having a first constituent and a second constituent that is different than the first constituent. The first constituent forms a first intermetallic with a portion of the silicon matrix and the second constituent forms a second intermetallic with another portion of the silicon matrix, wherein the braze layer is formulated to provide a barrier to oxygen diffusion therethrough.