Abstract: Improved coating compositions are described for the protection of superalloys at elevated temperatures. The coatings of the NiCrAlY or NiCoCrAlY type are significantly improved by the use of higher levels of yttrium.
Abstract: Apparatus for delivering two or more powders at any controlled ration to a thermal spray apparatus permits the controlled production of graded sprayed coatings. The apparatus also monitors and controls the position of the spray apparatus relative to the workpiece and varies this position during the deposition of the sprayed layers. The apparatus includes in-process mass flow gauges which measure in real time the flow rates of the various powders and report these rates to a supervisory controller which verifies these rates against the predetermined schedule and can shut down the apparatus in the event of a malfunction. The substrate being sprayed has its substrate temperature monitored and controlled according to a predetermined schedule by a supervising controller.
Type:
Grant
Filed:
November 28, 1984
Date of Patent:
September 23, 1986
Assignee:
United Technologies Corporation
Inventors:
Louis L. Packer, George S. Bosshart, Mark R. Jaworowski, Urban E. Kuntz
Abstract: Semiconductor thin films are produced using plasma assisted chemical vapor deposition on alkali halide single crystal substrates. Deposition is formed at relatively low temperatures so that sublimation of the substrate is not a problem. The invention process permits at high rate deposition of high quality semiconductors.
Abstract: A method is described for producing metallic articles, especially turbine disks, which have a hot-worked structure in one region and a warmworked structure in another region and thereby have properties which differ in different regions. The method comprises an initial hot-working step, an intermediate heat treatment step and a final warm-working step.
Abstract: Accurate measurements are made of powder entrained in a flowing gas stream. Measurements are made of the flowing gas stream prior to powder entrainment and x-ray measurement techniques are made to determine characteristics of the combined materials. An equation is disclosed for calculating the mass flow rate of the powder material from these measurements.
Abstract: Corrosion resistant, high strength, superalloy single crystal articles are described. Starting with a nominal composition of 11.75% Cr, 9% Co, 1.75% Mo, 4.5% W, 2.5% Ta, 2.5% Al, 4% Ti, balance essentially nickel, intentional additions are made of carbon and extra tantalum. From 0.05-0.15% carbon is added along with sufficient tantalum to combine with the carbon to form tantalum carbon. The resultant articles have substantially improved hot corrosion resistance and creep properties.
Abstract: Methods of coating metallic substrates with continuously graded metallic-ceramic material are disclosed. The method maintains low stress to strength ratios across the depth of the graded layer when the graded layer is under subsequent operative conditions. In one particular structure, the coating is applied to a metal substrate and includes a metallic bond coat a continuously graded metallic-ceramic layer and an outer layer of abradable ceramic material. Modulation of the metal substrate temperature during the coating process establishes a desired residual stress pattern in the graded layer.
Abstract: Improved coating compositions are described for the protection of superalloys at elevated temperatures. The coatings are of the MCrAlY type where M is nickel or cobalt and are significantly improved by the addition of from 0.1-7% silicon and 0.1-2% hafnium. Coatings of the invention are preferably applied by plasma spraying and as so applied are found to be substantially more effective than prior art coatings.
Abstract: Concepts relating to the heat treatment of single crystal superalloy articles are disclosed. A first concept is the use of a heat treatment sequence which includes incipient melting of the article being heat treated followed by one or more steps which essentially heal the incipient melting damage. A second concept relates to the treatment of previously heat treated single crystal articles which have incipient melting. Methods are disclosed for healing this damage and for recovering the mechanical properties of such articles. A third concept disclosed is a particular cycle which permits effective heat treatment of a specific single crystal alloy composition.
Type:
Grant
Filed:
June 6, 1983
Date of Patent:
April 22, 1986
Assignee:
United Technologies Corporation
Inventors:
Thomas T. Field, Otis Y. Chen, Arthur R. Geary, Richard W. Salkeld, Nicholas E. Ulion
Abstract: Forging processes are described for cast superalloys. The forgeability of superalloy materials is improved by the development of overaged microstructure. The total forging process is usually performed in a series of steps with intervening heat treatments to reform the overaged microstructure.
Type:
Grant
Filed:
December 27, 1983
Date of Patent:
April 1, 1986
Assignee:
United Technologies Corporation
Inventors:
Daniel F. Paulonis, David R. Malley, Edgar E. Brown
Abstract: Methods for increasing the forgeability of cast superalloy materials are described. An extremely overaged microstructure is developed by solutionizing the material and slow cooling in the vicinity of the solvus temperature to cause a precipitation of extremely coarse gamma prime material. Subsequently the material can be isothermally forged.
Abstract: Metal-working dies which are typically made of steel are provided with substantially enhanced life by receiving a plasma-sprayed refractory metal coating which is subsequently compacted under conditions of minimum shear stress. The number of working cycles which can be obtained from a die before it is necessary to rework the die can be improved by as much as 3500%.
Type:
Grant
Filed:
April 30, 1985
Date of Patent:
February 25, 1986
Assignee:
United Technologies Corporation
Inventors:
Harold C. Sanborn, Frank Carago, John R. Kreeger
Abstract: A method is described for improving the oxidation durability of overlay coatings. By polishing the surface to reduce the surface roughness to less than about 15 microinches AA the initial oxidation durability of the material, the point at which oxide spallation is first observed, can be increased from about 5 hours to about 200-300 hours.
Type:
Grant
Filed:
October 29, 1984
Date of Patent:
February 11, 1986
Assignee:
United Technologies Corporation
Inventors:
John S. Przybyszewski, Richard G. Claing
Abstract: Nickel base superalloys intended for use at low to moderate temperatures are provided with improved corrosion resistance by the addition of from 0.2 to 0.6% manganese. The manganese addition also improves the creep properties of the alloys. The manganese modified alloys are suited for use as elements in gas turbine engines for marine environments.
Abstract: An abradable/abrasive seal system having particular utility in gas turbine engines is described. The seal system includes an abrasive layer (40) which prevents direct interaction between components (30, 20) having relative motion and an abradable layer (43) which provides an effective degree of fluid sealing between the components.
Abstract: Concepts for producing thermal conditions, in strip material, conducive to directional recrystallization are disclosed. An inductively heated susceptor contains a slot and the susceptor shape develops a thermal condition where the edges of the strip are cooler than the center of the slot. The furnace includes a fluid cooled cold zone as well as the hot zone and can produce a steep longitudinal thermal gradient in the strip.
Abstract: Honeycomb structures, such as those used in turbine engine abradable seals, are provided with a uniform density filling of a suitable abradable material. The abradable material is prepared as a tape preform using an organic binder. The preform is forced into the honeycomb using a rubber tool.
Abstract: Carbon-carbon composite materials are provided with significantly enhanced oxidation resistance by the formation of a SiC coating. The coating is produced from a pack containing a small but effective amount of boron. The balance of the pack is preferably based on Al.sub.2 O.sub.3, SiO.sub.2, and Si. The composite to be coated is embedded in the pack and heated to an elevated temperature. The boron addition provides a conversion SiC coating having enhanced resistance to oxidation.
Abstract: Process for improving the crack growth behavior of titanium alloys containing substantial beta stabilizers and at least 3% molybdenum, such as Ti-6-2-4-6. The process includes the steps of forging above the beta transus temperature, cooling at a controlled rate through the beta transus temperature, heating to a temperature between 50.degree.-150.degree. F. below the beta transus temperature, cooling the alloy at a rate in excess of that produced by air cooling, and aging the material between about 900.degree. F. and 1100.degree. F. The resultant material has substantially improved crack growth behavior when contrasted with material processed according to the prior art.
Type:
Grant
Filed:
October 31, 1983
Date of Patent:
September 24, 1985
Assignee:
United Technologies Corporation
Inventors:
Douglas M. Berczik, George Brodi, Thomas E. O'Connell
Abstract: Improved coating compositions are described for the protection of superalloys at elevated temperatures. The coatings are of the MCrAlY type where M is nickel or cobalt and are significantly improved by the addition of from 0.1-7% silicon and 0.1-2% hafnium. Coatings of the invention are preferably applied by plasma spraying and as so applied are found to be substantially more effective than prior art coatings.