Abstract: A protected article has a substrate and a protective structure overlying a surface of the substrate. The protective structure includes a protective layer overlying the surface of the substrate and having an aluminum content greater than that of the substrate, and a bond-coat layer of a bond-coat-layer metal. The bond-coat-layer metal has a bond-coat initial composition having at least about 60 percent by weight platinum, rhodium, palladium, or combinations thereof. There may be a diffusion-barrier layer between the surface of the substrate and the protective layer, and there may be a ceramic thermal barrier coating overlying the bond-coat layer.

Abstract: A process for protecting a thermal barrier coating (TBC) on a component used in a high-temperature environment, such as the hot section of a gas turbine engine. The process applies a protective film on the surface of the TBC to resist infiltration of contaminants such as CMAS that can melt and infiltrate the TBC to cause spallation. The process generally entails applying to the TBC surface a metal composition containing at least one metal whose oxide resists infiltration of CMAS into the TBC. The metal composition is applied so as to form a metal film on the TBC surface and optionally to infiltrate porosity within the TBC beneath its surface. The metal composition is then converted to form an oxide film, with at least a portion of the oxide film forming a surface deposit on the TBC surface.

Abstract: A modified platinum group metal coating composition comprising a phase having a solid solution face-centered cubic (fcc) crystal structure, rich in platinum group materials. In order to be effective, the platinum group metal coating material was modified based on the chemical composition and chemical activity of the substrate material. The platinum group metal coating material was modified to include, in solid solution, elements of the superalloy substrate, specifically nickel (Ni) and cobalt (Co). Depending on the substrate material, the modified platinum group metal coating material may not even include Ni or Co, but may be modified to include amounts of different elements that are consistent with the chemical composition of the substrate. The modified platinum metal coating material also includes aluminum (Al). The composition may include small amounts of a second phase isolated within the fcc phase matrix.

Abstract: In accordance with an embodiment of the invention, an article is provided. The article comprises a substrate comprised of silicon containing material, an environmental barrier coating (EBC) overlying the substrate and a thermal barrier coating (TBC) on the environmental barrier coating. The thermal barrier coating comprising a compound having a rhombohedral phase.

Abstract: Ceramic compositions comprising at least about 91 mole % zirconia and up to about 9 mole % of a stabilizer component comprising a first metal oxide having selected from the group consisting of yttria, calcia, ceria, scandia, magnesia, india and mixtures thereof. This stabilizer component further comprises a second metal oxide of a trivalent metal atom selected from the group consisting of lanthana, gadolinia, neodymia, samaria, dysprosia, erbia, ytterbia, and mixtures thereof. These ceramic compositions are useful in preparing thermal barrier coatings having reduced thermal conductivity for the metal substrate of articles that operate at, or are exposed to, high temperatures.

Abstract: Methods for depositing an overlay coating on articles intended for use in hostile thermal environments. The coating has a predominantly gamma prime-phase nickel aluminide (Ni3Al) composition suitable for use as an environmental coating and as a bond coat of a thermal barrier coating system. The coating further contains at least one platinum group metal, preferably chromium, optionally one or more reactive elements, and optionally silicon. The coating is deposited by a process that entails forming a platinum group metal layer and at least one separate layer of other constituents of the coating, and then performing a diffusion heat treatment to yield the coating.

Abstract: Zirconia-containing ceramic compositions that are capable of providing thermal barrier coatings wherein the zirconia is stabilized in the cubic crystalline phase. These compositions comprise at least about 50 mole % zirconia and a stabilizing amount up to about 49 mole % of a stabilizer component comprising: (1) a first metal oxide selected from the group consisting of ytterbia, neodymia, mixtures of ytterbia and neodymia, mixtures of ytterbia and lanthana, mixtures of neodymia and lanthana, and mixtures of ytterbia, neodymia and lanthana in an amount of from about 5 to about 49 mole % of the composition; and (2) a second metal oxide selected from the group consisting of yttria, calcia, ceria, scandia, magnesia, india and mixtures thereof in an amount of about 4 mole % or less of the composition. The ceramic composition further comprises one or more of a third metal oxide selected from the group consisting of: (a) hafnia in an amount from about 0.

Abstract: A coating suitable for use as an environmentally-protective coating on surfaces of components used in hostile thermal environments, including the turbine, combustor and augmentor sections of a gas turbine engine. The coating is used in a coating system deposited on a substrate formed of a superalloy material. The coating contacts a surface of the superalloy substrate and is formed of a coating material having a tensile strength of more than 50% of the superalloy material. The coating material is predominantly at least one metal chosen from the group consisting of platinum, rhodium, palladium, and iridium, and has sufficient strength to significantly contribute to the strength of the component on which the coating is deposited.

Abstract: A turbine airfoil having an improved impact and erosion resistance. The airfoil comprises: (a) a base segment having an impact resistant leading edge section proximate to the leading edge comprising a material having having a yield strength of least about 250 ksi and an elongation percentage of about 12% or less; and (b) an erosion resistant coating overlaying the base segment at least in the leading and trailing edge portions of the pressure side, the erosion resistant coating comprising at least one ceramic layer having at least one of the following properties: (1) an erosion value of at least about 200 g. of erodent to cause a thickness loss of about 15–20 microns; (2) an erosion volume loss value (V) of about 1.9 or less as defined by the equation V=H?0.18×E0.75×F?1.65 where H is hardness, E is elastic modulus and F is fracture toughness; and (3) an F value of at least about 1.5 MPa*m1/2.

Abstract: A damaged gas turbine blade which has previously been in service, and which is made of a base metal, is furnished. Any damaged material is removed from the damaged blade tip. The damaged blade tip is weld repaired with a nickel-base superalloy that is more resistant to oxidation resistance than is the base metal in the operating environment of the tip-repaired gas turbine blade. The method does not include any step of coating a lateral surface of the repaired blade tip with a non-ceramic coating after the step of weld repairing.

Abstract: A thermal barrier coating (TBC) for a component intended for use in a hostile thermal environment. The TBC has an interior region and an outer surface region on and contacting the interior region. Both regions are formed of a ceramic material, with the interior region having a lower thermal conductivity than zirconia partially stabilized by about seven weight percent yttria. The interior region constitutes more than half of the thickness of the TBC, and the outer surface region constitutes less than half of the thickness of the TBC. The TBC has a columnar microstructure whereby the interior region and the outer surface region comprise columns of their ceramic materials. The outer surface region is more erosion and impact resistant than the interior region at least in part as a result of the columns thereof being more closely spaced than the columns of the interior region.

Abstract: An alloy and a gas turbine engine component comprising an alloy are presented, with the alloy comprising: palladium, in an amount ranging from about 1 atomic percent to about 41 atomic percent; platinum, in an amount that is dependent upon the amount of palladium, such that a. for the amount of palladium ranging from about 1 atomic percent to about 14 atomic percent, the platinum is present up to about an amount defined by the formula (40+X) atomic percent, wherein X is the amount in atomic percent of the palladium, and b. for the amount of palladium ranging from about 15 atomic percent up to about 41 atomic percent, the platinum is present in an amount up to about 54 atomic percent; and the balance comprising rhodium, wherein the rhodium is present in an amount of at least 24 atomic percent; wherein the alloy comprises a microstructure that is essentially free of L12-structured phase at a temperature greater than about 1000° C.

Abstract: A turbine engine component comprising a substrate made of a nickel-base or cobalt-base superalloy and a protective coating overlying the substrate, the coating formed by electroplating at least two platinum group metals selected from the group consisting of platinum, palladium, rhodium, ruthenium and iridium. The protective coating is typically heat treated to increase homogeneity of the coating and adherence with the substrate. The component typically further comprises a ceramic thermal barrier coating overlying the protective coating. Also disclosed are methods for forming the protective coating on the turbine engine component by electroplating the platinum group metals.

Abstract: Ceramic compositions comprising at least about 91 mole % zirconia and up to about 9 mole % of a stabilizer component comprising a first metal oxide having selected from the group consisting of yttria, calcia, ceria, scandia, magnesia, india and mixtures thereof. This stabilizer component further comprises a second metal oxide of a trivalent metal atom selected from the group consisting of lanthana, gadolinia, neodymia, samaria, dysprosium, and mixtures thereof and a third metal oxide of a trivalent metal atom selected from the group consisting of erbia, ytterbia and mixtures thereof. These ceramic compositions are useful in preparing thermal barrier coatings having reduced thermal conductivity for the metal substrate of articles that operate at, or are exposed to, high temperatures.

Abstract: A test method for testing the thermal mechanical fatigue performance of a test material includes preparing a test specimen of the test material, wherein the test specimen has a base, and a rib extending outwardly from the base. The test specimen is thermally cycled through at least one test cycle. In each test cycle the rib is heated to a higher rib temperature and thereafter cooled to a lower rib temperature. The test specimen is evaluated for thermal mechanical fatigue damage.

Abstract: A turbine engine component comprising a substrate made of a nickel-base or cobalt-base superalloy, a non-metallic oxide or nitride diffusion barrier layer overlying the substrate, and a protective coating overlying the barrier layer, the protective coating comprising at least one platinum group metal selected from the group consisting of platinum, palladium, rhodium, ruthenium and iridium. The diffusion barrier layer may be a deposited or thermally grown oxide material, especially aluminum oxide. The protective coating may be heat treated to increase homogeneity of the coating and adherence with the substrate. The component typically further comprises a ceramic thermal barrier coating overlying the protective coating. Also disclosed are methods for forming a protective coating system on the turbine engine component by forming the non-metallic oxide or nitride diffusion barrier layer on the substrate and then depositing the platinum group metal on top of the barrier layer.

Abstract: A thermal barrier coatings for the underlying substrate of articles that operate at, or are exposed to, high temperatures. The thermal barrier coating includes a zirconia-containing upper layer wherein the zirconia is stabilized in the cubic crystalline phase to reduce the thermal conductivity of the coating. The thermal barrier coating further includes a zirconia-containing lower layer stabilized in the tetragonal crystalline phase that increases the adherence of the upper layer to the bond coat layer that overlies the substrate of the article to improve the resistance of the coating to spallation.

Abstract: Zirconia-containing ceramic compositions having a c/a ratio of the zirconia lattice in the range of from about 1.005 to about 1.016. These compositions comprise a stabilizing amount up to about 10 mole % of the composition of a stabilizer component which comprises: (1) a first metal oxide selected from the group consisting of yttria, calcia, ceria, scandia, magnesia, india and mixtures thereof in an amount of from about 1.5 to about 6 mole % of the composition of; (2) a second metal oxide selected from the group consisting of lanthana, neodymia and mixtures thereof in an amount of from about 0.5 to about 4 mole % of the composition; and (3) optionally ytterbia in an amount of from about 0.5 to about 4 mole % of the composition. These compositions further comprise hafnia in an amount of from about 0.5 to about 15 mole % of the composition; and optionally tantala in an amount of from about 0.5 to about 1.5 mole % of the composition.

Abstract: A protected article includes a nickel-base superalloy substrate, an interlayer overlying the substrate, and a protective layer overlying the interlayer. The protective layer has a composition comprising at least one of rhodium, platinum, palladium, and ruthenium. In one composition, palladium is present in an amount of from about 1 to about 41 atomic percent; platinum is present in an amount of about (40+atomic percent palladium) atomic percent for palladium ranging from about 1 atomic percent to about 14 atomic percent and up to about 54 atomic percent for palladium ranging from about 15 atomic percent up to about 41 atomic percent; rhodium is present in an amount of at least about 24 atomic percent; zirconium, hafnium, titanium, and mixtures thereof are present in an amount of from zero up to about 5 atomic percent; and ruthenium is present in an amount of from zero up to about 5 atomic percent, balance impurities.

Abstract: A protected article includes a nickel-base superalloy substrate, an interlayer overlying the substrate, and a protective layer overlying the interlayer. The protective layer has a composition comprising at least one of rhodium, platinum, palladium, and ruthenium. In one composition, palladium is present in an amount of from about 1 to about 41 atomic percent; platinum is present in an amount of about (40+atomic percent palladium) atomic percent for palladium ranging from about 1 atomic percent to about 14 atomic percent and up to about 54 atomic percent for palladium ranging from about 15 atomic percent up to about 41 atomic percent; rhodium is present in an amount of at least about 24 atomic percent; zirconium, hafnium, titanium, and mixtures thereof are present in an amount of from zero up to about 5 atomic percent; and ruthenium is present in an amount of from zero up to about 5 atomic percent, balance impurities.