Superabrasive tools and methods for the making thereof are disclosed and described. In one aspect, superabrasive particles are chemically bonded to a matrix support material according to a predetermined pattern by a braze alloy. The brazing alloy may be provided as a powder, thin sheet, or sheet of amorphous alloy. A template having a plurality of apertures arranged in a predetermined pattern may be used to place the superabrasive particles on a given substrate or matrix support material.

Brazed diamond tools and methods for making the same

A metallic article (10) comprises a bond coating (14,16) on the metallic article (10) and a ceramic thermal barrier coating (18) on the bond coating (14,16). The ceramic thermal barrier (18) coating comprises zirconia stabilized with yttria, calcia, magnesia or india, and erbia to reduce the thermal conductivity of the ceramic thermal barrier coating (18). The ceramic thermal barrier coating (18) is at least 100 microns thick. The erbium atom has an atomic mass greater than the average atomic mass of the zirconium, the yttrium, calcium, magnesium or indium and the oxygen atoms to reduce phonon thermal conductivity of the ceramic thermal barrier coating (18). The ceramic thermal barrier coating (18) comprises 4 to 20 wt % of yttria, 5 to 25 wt % of erbia and the balance is zirconia plus incidental impurities. The erbia absorbs energy in the 0.3 microns to 5 microns waveband to reduce photon thermal conductivity. Other suitable additions besides erbia are dysprosia, europia, gadolinia, praseodymia, urania or ytterbia.

A metallic article having a thermal barrier coating and a method of application thereof

A ceramic composition for insulating components, made of ceramic matrix composites, of gas turbines is provided. The composition comprises a plurality of hollow oxide-based spheres of various dimensions, a phosphate binder, and at least one oxide filler powder, whereby the phosphate binder partially fills gaps between the spheres and the filler powders. The spheres are situated in the phosphate binder and the filler powders such that each sphere is in contact with at least one other sphere and the arrangement of spheres is such that the composition is dimensionally stable and chemically stable at a temperature of approximately 1600 °C. A stationary vane of a gas turbine comprising the composition of the present invention bonded to the outer surface of the vane is provided. A combustor comprising the composition bonded to the inner surface of the combustor is provided. A transition duct comprising the insulating coating bonded to the inner surface of the transition is provided. Because of abradable properties of the composition, a gas turbine blade tip seal comprising the composition also is provided. The composition is bonded to the inside surface of a shroud so that a blade tip carves grooves in the composition so as to create a customized seal for the turbine blade tip.

Use of high temperature insulation for ceramic matrix composites in gas turbines

A method is described for improving the cooling effectiveness of a fluid which flows through a row of passage holes in a substrate (e.g., a turbine component), out to a high-temperature surface of the substrate. The method involves forming a slot over the holes, within the high temperature surface of the substrate. The slot can be formed within protective coatings applied over the substrate. Alternatively, it can be formed partially within the substrate, and partially within the protective coatings. Movement of a film coolant through the substrate and into the slot results in greater cooling effectiveness. Related articles are also described.

A method for improving the cooling effectiveness of a gaseous coolant stream, and related articles of manufacture

A thermal barrier coating system for high temperature superalloys includes an intermetallic bond coating on the substrate and a ceramic topcoat having a columnar grain structure with the columnar axis perpendicular to the surface of the coating. The intermetallic coating is preferably a nickel aluminide or a platinum aluminide, whose upper surface is oxidized during processing to form a thin layer of predominantly aluminum oxide. The ceramic topcoat is preferably zirconium oxide having from about 6 to 20 percent yttrium oxide.

Thermal barrier coating system with intermetallic overlay bond coat

An abradable ceramic seal coating on at least one of a pair of members having relative rotational movement, the coating being formed of stabilized zirconia which is codeposited with a thermally decomposable organic powder, the codeposited layer being heated to decompose the organic filler and produce a porous coating of from about 20 to about 33% voids.

Abradable ceramic seal and method of making same

An abrasive system and a processing procedure is provided which permits the direct installation of a thick abrasive blade tip cap onto a cast single crystal turbine rotor blade during a single heating schedule requiring only one furnace operation. The composition of the abrasive blade tip cap advantageously utilizes the high temperature performance capabilities of the single crystal alloy without significantly affecting its mechanical properties as a consequence of the processing necessary to permanently bond the abrasive blade tip cap to the rotor blade. A semi-rigid blade tip cap preform is first formed and positioned on the tip of the rotor blade. The preform and rotor blade are then heated in a vacuum furnace according to a temperature schedule entailing heating rates, holding temperatures and durations which are sufficient to bond and consolidate the preform. The rotor blade is then rapidly cooled in the vacuum furnace to retain the single crystal structure of the rotor blade.

Abrasive blade tips for cast single crystal gas turbine blades

An abrasive system and a processing procedure is provided which permits the direct installation of a thick abrasive blade tip cap onto a cast turbine rotor blade during a heating schedule which requires two furnace operations. The composition of the abrasive blade tip cap advantageously utilizes the high temperature performance capabilities of equiaxed or single crystal rotor blade alloys without significantly affecting their mechanical properties as a consequence of the processing necessary to permanently bond the abrasive blade tip cap to the rotor blade. A semi-rigid mat consisting of the preferred abrasive composition is first consolidated in a first vacuum furnace operation. Blade tip cap preforms are then cut from the mat and positioned on the tip of the rotor blade. The preform and rotor blade are then heated in a vacuum furnace according to a temperature schedule entailing heating rates, holding temperatures and durations which are sufficient to bond the preform to the rotor blade. The rotor blade is then rapidly cooled in the vacuum furnace to retain the microstructure and mechanical properties of the rotor blade.

Method for bonding abrasive blade tips to the tip of a gas turbine blade

An improved method for coating a porous metal laminated structure having air flow holes on the coated side of the structure including in part, the steps of roughening an exposed surface of the porous laminated material and thereafter spraying a bond layer on the roughened surface at an angle selected to coat it with a thin bond coat layer while depositing only a limited amount of the bond coat material internally of the air flow holes and thereafter spray coating the bond coated surface with a top ceramic coat of heat resistant composition and characterized by requiring a bond coat for adherence to the porous metal laminated material and wherein the top ceramic coat spray angle is inclined opposite to that of the spray angle of deposition of the bond coat material to prevent deposition of the top coat on bond material internally of the air flow holes so as to prevent bonding of the ceramic top coat in the air flow holes thereby to minimize restriction of flow through the air flow hole in the exposed surface of the porous metal laminate.

Method for coating porous metal structure

A method of applying a thermal barrier coat on an exposed side of a porous metal laminate which method includes the steps of spreading on the laminate an air-curable maskant to force maskant into the perforations in the exposed side, removing excess maskant from the exposed side so that maskant plugs remain in the perforations with tops generally coplanar with the exposed side, allowing the maskant to cure, directing bond coat and top coat sprays at the exposed side of the porous laminate to deposit a thermal barrier coat thereon but not on the maskant plugs, and removing the maskant plugs by thermal and chemical treatment or by chemical treatment alone.

David Lee Clingman

Papers

Abradable ceramic seal and method of making same

Abrasive blade tips for cast single crystal gas turbine blades

Method for bonding abrasive blade tips to the tip of a gas turbine blade

Method for coating porous metal structure

Porous laminate surface coating method