Coated article and method for producing the coated article. The article (1) is coated with a system which provides protection against oxidation and corrosion and which significantly reduces the substrate temperature. An MCrAlY layer (2) is applied to the article (1) to be protected and a columnar grain ceramic (4) is applied by vapor deposition to the MCrAlY coated article. An alumina layer (3) which exists between the MCrAlY layer (2) and the columnar ceramic layer (4) provides for the adherence of the columnar layer to the MCrAlY layer.

Columnar grain ceramic thermal barrier coatings

Coated article and method for producing the coated article. The article (1) is coated with a system which provides protection against oxidation and corrosion and which significantly reduces the substrate temperature. An MCrAlY layer (2) is applied to the article to be protected and a columnar grain ceramic (5) is applied by vapor deposition to the MCrAlY coated article. An alumina layer (4) which exists between the MCrAlY layer (2) and the columnar ceramic layer (5) provides for the adherence of the columnar layer to the MCrAlY layer. An important feature of the invention is that the interface (3) between the MCrAlY layer and the alumina layer has a low surface roughness and this greatly improves the columnar ceramic layer adherence.

Columnar grain ceramic thermal barrier coatings on polished substrates

A thermal barrier protected nickel based or cobalt based superalloy component for use in a gas turbine engine includes a thermal barrier coating system having a multi-layered structure. The first bondcoat layer of the thermal barrier coating system comprises a chemical vapor deposited, platinum modified diffusion aluminide layer on the superalloy component (substrate). The diffusion aluminide layer includes an inner diffusion zone proximate the substrate and an outer layer region comprising a platinum modified (platinum-bearing) intermediate phase of aluminum and at least one of nickel and cobalt depending on the superalloy composition. The intermediate phase is a non-ordered solid solution having a range of compositions and is free of other phase constituents. The intermediate phase has an average aluminum concentration in the range of about 18 to about 26% by weight, an average platinum concentration in the range of about 8 to about 35% by weight, and an average nickel concentration in the range of about 50 to 60% by weight and is non-stoichiometric relative to intermetallic compounds of aluminum and nickel, aluminum and cobalt, and aluminum and platinum. An adherent alpha alumina layer is thermally grown on the diffusion aluminide layer and receives an outer ceramic thermal barrier layer deposited thereon.

Thermal barrier coating system with intermediate phase bondcoat

A method is provided for manufacturing a component. The method includes forming a diffusion coating on a first intermediate article formed by an additive manufacturing process. The diffusion coating is removed from the first intermediate article forming a second intermediate article having at least one enhanced surface. The diffusion coating is formed by applying a layer of coating material on at least one surface of the first intermediate article and diffusion heat treating the first intermediate article and the layer. The diffusion coating comprises a surface additive layer and a diffusion layer below the surface additive layer. The formation of the diffusion coating and removal thereof may be repeated at least once.

Methods for manufacturing components from articles formed by additive-manufacturing processes

A coated article and method for producing the coated article are described. The article is coated with a system which provides protection against oxidation and corrosion and which significantly reduces the substrate temperature. An MCrAlY layer is applied to the article to be protected and a columnar grain ceramic is applied by vapor deposition to the MCrAlY coated article. An alumina layer which exists between the MCrAly layer and the columnar ceramic layer provides for the adherence of the columnar layer to the MCrAlY layer.

Method for producing columnar grain ceramic thermal barrier coatings

A process for providing coatings on metal articles whereby the articles will be resistant to corrosion at elevated temperatures. The process involves the application of an overlay on an article surface, the overlay comprising a ductile metal of a composition normally resistant to corrosion at elevated temperatures. An outer layer of aluminide or metal which is resistant to corrosion at elevated temperatures but which is subject to embrittlement at such temperatures is applied to complete the coating. Porosity in the coating is then eliminated and a high integrity corrosion resistant coating not subject to cracking is obtained by heating the article in a gaseous atmosphere to elevated temperature and simultaneously applying isostatic pressure to the article.

Process for producing elevated temperature corrosion resistant metal articles

A method for the production of metal articles resistant to corrosion at elevated temperatures. The method involves the application of a first coating on an article surface, this coating comprising a cobalt, iron or nickel alloy which is compatible with the substrate and which is ductile in character. A second coating highly resistant to corrosion at elevated temperatures is applied over the first coating to form a composite coating, and an elevated temperature treatment follows to provide interfacial bonding and to minimize the detrimental effects of thermal and mechanical stresses encountered during use. The provision of a ductile first layer provides a barrier against degradation of the corrosion resistance of the outer layer and serves as a barrier against detrimental interdiffusion and crack propagation.

Method for producing elevated temperature corrosion resistant articles

A preformed fiber reinforced metal matrix composite reinforcement insert is clad or covered with a material that is effective to avoid the adverse reactions between the insert/melt and any exposed insert fibers/matrix. The clad insert is suspended in the mold cavity and a melt is introduced into the mold cavity about the clad insert. The melt is solidified about the clad insert to provide a casting of the solidified melt having the clad insert disposed therein to reinforce the casting.

Method of making composite castings using reinforcement insert cladding

A method for producing precision shapes which includes the consolidation of powder metal preforms into a shaped porous preform. A first coating is applied to the preform, this first coating being porous while providing a diffusion barrier. A second coating which is also initially porous is then applied and the coated preform can then be degasified by subjecting the preform to a vacuum, particularly at elevated temperatures. The coated preform is then heated under vacuum to a temperature such that the second coating is densified to the extent that it becomes non-porous. Finally, the preform is subjected to a hot isostatic pressing operation whereby formation of high integrity, fully dense metal shape results.

Method for the production of precision shapes

A method for treating investment cast superalloy castings wherein the portions of the castings which solidify directly against the mold walls comprise a substantially continuous or encapsulating skin of a metallic and/or nonmetallic composition. In such castings, defects in the form of material voids, including defects present immediately beneath the skin, are eliminated by the application of heat and pressure. The castings are heated to temperatures sufficient to achieve metal movement in the form of yield or creep, and a pressure of at least about 10,000 psi is applied by means of a surrounding gaseous atmosphere. The heat and pressure application deforms the material in the area of the voids and consolidates this material to substantially remove the voids and to thereby improve the performance characteristics of the castings. The encapsulating skin also serves as a protective coating during the hot isostatic pressing whereby contamination of the casting by elements such as oxygen or nitrogen in the furnace atmosphere is avoided, or drastically reduced. By eliminating surface defects and avoiding surface contamination, the investment castings are cast to substantially exact final dimensions since finishing operations are minimized.

William R. Freeman

Papers

Process for producing elevated temperature corrosion resistant metal articles

Method for producing elevated temperature corrosion resistant articles

Method of making composite castings using reinforcement insert cladding

Method for the production of precision shapes

Method for treating superalloy castings