Abstract: 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.

Abstract: 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.

Abstract: 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 MCrAIY 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 either unstabilized zirconia, unstabilized hafnia, or a mixture thereof.

Abstract: A method for making a bimetallic ring seal having a nickel core covered by a first layer of platinum having a inner dense portion and a second outer portion both of which plastically deform in the presence of a load. The method includes the step of applying a porous layer of platinum over the dense layer by electroless plating in a platinum bath comprising 0.8-1.2 gram/liter platinum as diammine dinitrite salt Pt(NH3)2(NO2)2, 50-100 milliliter/liter of 25% ammonium hydroxide NH4OH; and 0.3-1.5 gram/liter hydrazine hydrate N2H4—H2O, at a temperature in the range of 75-90° C. and at a plating rate in the range of 0.5-3.0 micron/hour and then plastically deforming the ring seal under load.

Abstract: A electrolyte for use in electrolytic 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). A method of improving oxidation resistance of a platinum modified aluminide diffusion coating on a substrate, comprises electroplating the substrate using this electrolyte and then aluminizing the electroplated substrate at an elevated temperature to grow a platinum modified aluminide diffusion coating.

Abstract: 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).

Abstract: A turbine shroud having a coating comprising a bond layer covering the shroud substrate, and a thick ceramic stabilized zirconia layer with a segmented morphology covering the bond coat. The segmented morphology is defined by an array of slots or grooves which extend from the outer surface of the ceramic layer inwards through almost the entire thickness of the coating but without piercing the underlying substrate. The segmented morphology comprises a plurality of grooves that are laser drilled into the ceramic layer. Each groove is formed by laser drilling a series of holes that are spaced from each other so that the groove has a fully segmented portion and a partially segmented portion.

Abstract: A compliant sleeve for attaching a ceramic member to a metal member is comprised of a superalloy substrate having a metal contacting side and a ceramic contacting side. The ceramic contacting side is plated with a layer of nickel followed by a layer of platinum. The substrate is then oxidized to form nickel oxide scale on the ceramic contacting side and a cobalt oxide scale on the metal contacting side. A lubricious coating of boron nitride is then applied over the metal contacting side, and a shear-stress limiting gold coating is applied over the ceramic contacting side.

Abstract: 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.

Abstract: A thermal barrier coating for superalloy turbine engine vanes and blades that are exposed to high temperature gas is disclosed. The coating includes a ceramic layer applied to an aluminide or MCrAlY bond coat by electron beam physical vapor deposition. The ceramic layer has a first portion having unstabilized porosity, a second portion, overlying the first portion, with stabilized porosity, and an outer portion wherein the pores are coated with a noble metal. The stabilized porosity portion along with the noble metal coating reduce the thermal conductivity of the ceramic layer. Stabilizing the porosity renders it more resistant to sintering densification at high temperatures.

Abstract: 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 either unstabilized zirconia, unstabilized hafnia, or a mixture thereof.

Abstract: An improvement in a thermal barrier coating for superalloy turbine engine components subjected to high operating temperatures, such as turbine airfoils, e.g., vanes and blades, is disclosed which eliminates the expensive MCrAlY oxidation resistant bond coating underlayer for a columnar grained ceramic thermal barrier coating. In accordance with my present invention, a relatively low cost thermal barrier coating system for superalloy turbine components is provided which utilizes a diffusion aluminide coating layer as the oxidation resistant bonding surface for the columnar grained ceramic insulating coating.

Abstract: A thermal barrier coating for superalloy turbine engine vanes and blades that are exposed to high temperature gas is disclosed. The coating includes a ceramic layer applied to an Aluminide or MCrAlY bond coat by electron beam physical vapor deposition. The ceramic layer has a first portion having unstabilized porosity, a second portion, overlying the first portion, with stabilized porosity, and an outer portion wherein the pores are coated with a noble metal. The stabilized porosity portion along with the noble metal coating reduce the thermal conductivity of the ceramic layer. Stabilizing the porosity renders it more resistant to sintering densification at high temperatures.

Abstract: A metallic regenerator seal is provided having multi-layer coating comprising a NiCrAlY bond layer, a yttria stabilized zirconia (YSZ) intermediate layer, and a ceramic high temperature solid lubricant surface layer comprising zinc oxide, calcium fluoride, and tin oxide. Because of the YSZ intermediate layer, the coating is thermodynamically stable and resists swelling at high temperatures.

Abstract: A metallic regenerator seal is provided having multi-layer coating comprising a NiCrAlY bond layer, a yttria stabilized zirconia (YSZ) intermediate layer, and a ceramic high temperature solid lubricant surface layer comprising zinc oxide, calcium fluoride, and tin oxide. An array of discontinuous grooves is laser machined into the outer surface of the solid lubricant surface layer making the coating strain tolerant.

Abstract: A ceramic thermal barrier coating system for superalloy components subjected to high operating temperatures, such as gas turbine engine airfoils, includes a high purity alumina interfacial layer between the metallic substrate and the ceramic overcoat in order to better resist failure by spalling.

Abstract: A piece of a titanium-base alloy having an elevated temperature phase transformation is diffusion bonded to a second phase at an accelerated rate or reduced temperature, as compared with conventional diffusion bonding, by manipulating the phase transformation with an alloying element that can be readily introduced into, and removed from, the titanium piece. The introduction of hydrogen into the titanium alloy reduces the temperature of the phase transformation. The titanium alloy can be repeatedly cycled through the phase transformation before or during bonding, by the introduction and removal of hydrogen, to reduce the flow stress through transformation plasticity. Alternatively, the titanium alloy may be loaded with hydrogen to reduce the phase transformation temperature, increasing the fraction of the more deformable phase and then reducing the flow stress of the alloy at the diffusion bonding temperature.

Abstract: An abradable ceramic coated turbine shroud structure includes a grid of slant-steps isolated by grooves in a superalloy metal shroud substrate. A thin NiCrAlY bonding layer is formed on the machined slant-steps. A stabilized zirconia layer is plasma sprayed on the bonding layer at a sufficiently large spray angle to cause formation of deep shadow gaps in the zirconia layer. The shadow gaps provide a high degree of thermal strain tolerance, avoiding spalling. The exposed surface of the zirconia layer is machined nearly to the shadow gap ends. The turbine blade tips are treated to minimize blade tip wear during initial abrading of the zirconia layer. The procedure results in very close blade tip-to-shroud tolerances after the initial abrading.

Abstract: A ceramic thermal barrier coating system for superalloy components subjected to high operating temperatures, such as gas turbine engine airfoils, is disclosed which includes a titania doped interfacial layer between the metallic substrate and the ceramic overcoat in order to better resist failure by spalling.

Abstract: A ceramic thermal barrier coating system for superalloy components subjected to high operating temperatures, such as gas turbine engine airfoils, is disclosed which includes a high purity alumina interfacial layer between the metallic substrate and the ceramic overcoat in order to better resist failure by spalling.