Abstract: A coating process using a welding electrode comprises the steps of: electro-spark depositing a composite on to a substrate, wherein the composite consists essentially of alumina particles in a matrix, wherein the matrix is a metal selected from the group consisting of aluminum or an aluminum alloy. The substrate herein is an aluminum alloy. The coatings involve only aluminum and aluminum compounds, thereby intermetallic compound formation and galvanic corrosion of the coating-substrate materials system is avoided.

Abstract: A protective coating for aluminum alloys, electrode for producing same and a coating process using the welding electrode. The protective coating and electrode comprise a composite consisting essentially of alumina particles in a matrix, wherein the matrix is a metal selected from the group consisting of aluminum or an aluminum alloy. The alumina particles consist of aluminum oxide in powder form. The coating process using the welding electrode above comprises the steps of: electro-spark depositing a composite on to a substrate, wherein the composite consists essentially of alumina particles in a matrix, wherein the matrix is a metal selected from the group consisting of aluminum or an aluminum alloy. The substrate herein is an aluminum alloy. The coatings involve only aluminum and aluminum compounds, thereby intermetallic compound formation and galvanic corrosion of the coating-substrate materials system is avoided.

Abstract: A protective coating for aluminum alloys, electrode for producing same and a coating process using the welding electrode. The protective coating and electrode comprise a composite consisting essentially of alumina particles in a matrix, wherein the matrix is a metal selected from the group consisting of aluminum or an aluminum alloy. The alumina particles consist of aluminum oxide in powder form. The coating process using the welding electrode above comprises the steps of: electro-spark depositing a composite on to a substrate, wherein the composite consists essentially of alumina particles in a matrix, wherein the matrix is a metal selected from the group consisting of aluminum or an aluminum alloy. The substrate herein is an aluminum alloy. The coatings involve only aluminum and aluminum compounds, thereby intermetallic compound formation and galvanic corrosion of the coating-substrate materials system is avoided.

Abstract: A wear band for a well drill pipe which is made up of a coil spring sized to fit at the joint of the well drill pipe or casing. The inner surface of the coil spring includes a textured coating such as a carbide. The outer surface includes a plurality of hydrodynamic dimples defined therein, and preferably both the outer surface and the inner surface are adapted to resist corrosion. The abrasive coating preferably consists essentially of 95% tungsten carbide and a binder of 5% cobalt and coats an amount of the inner surface in the range of 50% to 100%. The hydrodynamic dimples are generally tear drop in shape to act as miniature fluid pumps. As a result, the wear band can be mechanically attached to the drill pipe while eliminating the need for metallurgically-welded hardbands and therefore unaffecting the drill pipe properties and dimensions.

Abstract: A wear band for a well drill pipe which is made up of a coil spring sized to fit at the joint of the well drill pipe or casing. The inner surface of the coil spring includes a textured coating such as a carbide. The outer surface includes a plurality of hydrodynamic dimples defined therein, and preferably both the outer surface and the inner surface are adapted to resist corrosion. The abrasive coating preferably consists essentially of 95% tungsten carbide and a binder of 5% cobalt and coats an amount of the inner surface in the range of 50% to 100%. The hydrodynamic dimples are generally tear drop in shape to act as miniature fluid pumps. As a result, the wear band can be mechanically attached to the drill pipe while eliminating the need for metallurgically-welded hardbands and therefore unaffecting the drill pipe properties and dimensions.

Abstract: CVD aluminide coatings including a small concentration of a reactive, gettering element for surface active impurities dispersed therein are formed for improved oxidation resistance. The aluminide coatings are formed by CVD codeposition of Al and the gettering element on the substrate using coating gases for the gettering element generated either outside or inside the coating retort depending on the chlorination temperature needed for the particular gettering element.

Abstract: An outwardly grown diffusion aluminide bondcoat is formed on a superalloy substrate and has higher concentrations of Al and Pt and lower concentrations of harmful impurities (e.g. Mo, W, Cr, Ta, S, etc.) at an outermost region of the bondcoat than at an innermost region thereof adjacent the substrate. The bondcoat is pretreated prior to deposition of a ceramic thermal insulative layer in a manner that reduces grain boundary ridges on the outermost bondcoat surface without adversely affecting the outermost region thereof, and then is heat treated to thermally grow a stable alpha alumina layer on the bondcoat prior to deposition of a ceramic layer.

Abstract: Method of forming an outwardly grown aluminide diffusion coating on a superalloy substrate disposed in a coating retort including the steps of heating the substrate to a temperature of 900 to 1200 degrees C., flowing a coating gas comprising aluminum trichloride and a carrier gas through the coating retort at a flow rate of the coating gas of about 100 to about 450 standard cubic feet per hour, providing a concentration of aluminum trichloride in the retort of less than 1.4% by volume of the coating gas, and providing a total pressure of the coating gas in the coating retort of about 100 to about 450 Torr.

Abstract: Chemical vapor deposition apparatus and method are provided with coating gas distribution and exhaust systems that provide more uniform coating gas temperature and coating gas flow distribution among a plurality of distinct coating zones disposed along the length of a coating chamber.

Abstract: CVD aluminide coatings including a small concentration of a reactive, gettering element for surface active impurities dispersed therein are formed for improved oxidation resistance. The aluminide coatings are formed by CVD codeposition of Al and the gettering element on the substrate using coating gases for the gettering element generated either outside or inside the coating retort depending on the chlorination temperature needed for the particular gettering element.

Abstract: Chemical vapor deposition apparatus and method are provided with external metal halide gas generators that reduce leakage of air into the generators so as to improve efficiency of use of the metal charge residing in each generator.

Abstract: CVD aluminide coatings including a small concentration of a reactive, gettering element for surface active impurities dispersed therein are formed for improved oxidation resistance. The aluminide coatings are formed by CVD codeposition of Al and the gettering element on the substrate using coating gases for the gettering element generated either outside or inside the coating retort depending on the chlorination temperature needed for the particular gettering element.

Abstract: CVD aluminide coatings including a small concentration of a reactive, gettering element for surface active impurities dispersed therein are formed for improved oxidation resistance. The aluminide coatings are formed by CVD codeposition of Al and the gettering element on the substrate using coating gases for the gettering element generated either outside or inside the coating retort depending on the chlorination temperature needed for the particular gettering element.

Abstract: CVD aluminide coatings including a small concentration of a reactive, gettering element for surface active impurities dispersed therein are formed for improved oxidation resistance. The aluminide coatings are formed by CVD codeposition of Al and the gettering element on the substrate using coating gases for the gettering element generated either outside or inside the coating retort depending on the chlorination temperature needed for the particular gettering element.

Abstract: Chemical vapor deposition apparatus and method are provided with coating gas distribution and exhaust systems that provide more uniform coating gas temperature and coating gas flow distribution among a plurality of distinct coating zones disposed along the length of a coating chamber.

Abstract: Chemical vapor deposition apparatus and method are provided with external metal halide gas generators that reduce leakage of air into the generators so as to improve efficiency of use of the metal charge residing in each generator.

Abstract: An outwardly grown diffusion aluminide bondcoat is formed on a superalloy substrate and has higher concentrations of Al and Pt and lower concentrations of harmful impurities (e.g. Mo, W, Cr, Ta, S, etc.) at an outermost region of the bondcoat than at an innermost region thereof adjacent the substrate. The bondcoat is pretreated prior to deposition of a ceramic thermal insulative layer in a manner that reduces grain boundary ridges on the outermost bondcoat surface without adversely affecting the outermost region thereof, and then is heat treated to thermally grow a stable alpha alumina layer on the bondcoat prior to deposition of a ceramic layer.

Abstract: A chemical cleaning method for cleaning an internal passage of an engine-run gas turbine engine airfoil wherein the airfoil is immersed in an inorganic hydroxide medium at superambient temperature and atmospheric pressure for a short time to remove accumulated oxides and dirt from the internal passage. The hydroxide medium can comprise molten KOH and immersion times of the engine-run airfoil not exceeding 10 minutes are involved.

Abstract: An outwardly grown diffusion aluminide bondcoat is formed on a superalloy substrate and has higher concentrations of Al and Pt and lower concentrations of harmful impurities (e.g. Mo, W, Cr, Ta, S, etc.) at an outermost region of the bondcoat than at an innermost region thereof adjacent the substrate. The bondcoat is pretreated prior to deposition of a ceramic thermal insulative layer in a manner that reduces grain boundary ridges on the outermost bondcoat surface without adversely affecting the outermost region thereof, and then is heat treated to thermally grow a stable alpha alumina layer on the bondcoat prior to deposition of a ceramic layer.

Abstract: A chemical cleaning method for cleaning an internal passage of an engine-run gas turbine engine airfoil wherein the airfoil is immersed in an inorganic hydroxide medium at superambient temperature and atmospheric pressure for a short time to remove accumulated oxides and dirt from the internal passage. The hydroxide medium can comprise molten KOH and immersion times of the engine-run airfoil not exceeding 10 minutes are involved.