Abstract: A multi-step electrochemical stripping method includes providing a determined electrode potential between a reference electrode and an article submerged in an electrolyte; recording a current peak value of a current signal flowing through the article; removing the voltage provided to the article when the current signal falls to a determined first current value after passing the current peak value; refreshing the electrolyte; providing the determined electrode potential again for a determined time and determining whether the current signal is less than a determined second current value during the determined time, if not, goes back to the refreshing step; and if yes, the process ends.

Abstract: The present disclosure is directed to the use and manufacture of cooling features within a component used in a hot gas path, such as within a turbine. In one embodiment, channels are formed within an external surface of the component and filled with a removable material. The external surface and channels may then be coated with one or more layers, such as a structural layer and/or top coat. The removable material may then be removed to leave the channels free of the removable material.

Abstract: The present invention provides a method of protecting refinery equipment, the method comprising: (a) applying an uncured organic coating comprising a curable epoxy phenol novolac resin and a curing agent comprising a vicinal primary diamine moiety to a surface of refinery equipment susceptible to corrosion and/or wear; and (b) curing the uncured coating to form a cured coating having a viscosity of at least 2,000,000 centipoise; wherein the uncured organic coating has a viscosity of less than 500,000 centipoise, and wherein the uncured coating is substantially free of components comprising secondary and tertiary amine groups, and wherein the uncured coating is characterized by a latent viscosity of at least 2,000,000 when cured for 1 hour at 50° C.

Abstract: Methods of fabricating coated components using multiple types of fillers are provided. One method comprises forming one or more grooves in an outer surface of a substrate. Each groove has a base and extends at least partially along the outer surface of the substrate. The method further includes disposing a sacrificial filler within the groove(s), disposing a permanent filler over the sacrificial filler, disposing a coating over at least a portion of the substrate and over the permanent filler, and removing the first sacrificial filler from the groove(s), to define one or more channels for cooling the component. A component with a permanent filler is also provided.

Abstract: Methods of fabricating coated components using multiple types of fillers are provided. One method comprises forming one or more grooves in an outer surface of a substrate. Each groove has a base and extends at least partially along the outer surface of the substrate. The method further includes disposing a sacrificial filler within the groove(s), disposing a permanent filler over the sacrificial filler, disposing a coating over at least a portion of the substrate and over the permanent filler, and removing the first sacrificial filler from the groove(s), to define one or more channels for cooling the component. A component with a permanent filler is also provided.

Abstract: A reactor has an inner surface accessible to the hydrocarbon and comprising a sintered product of at least one of cerium oxide, zinc oxide, tin oxide, zirconium oxide, boehmite and silicon dioxide, and a perovskite material of formula AaBbCcDdO3-?. 0<a<1.2, 0?b?1.2, 0.9<a+b?1.2, 0<c<1.2, 0?d?1.2, 0.9<c+d?1.2, ?0.5<?<0.5. A is selected from calcium, strontium, barium, and any combination thereof. B is selected from lithium, sodium, potassium, rubidium, and any combination thereof. C is selected from cerium, zirconium, antimony, praseodymium, titanium, chromium, manganese, ferrum, cobalt, nickel, gallium, tin, terbium and any combination thereof.

Abstract: Methods of fabricating coated components using multiple types of fillers are provided. One method comprises forming one or more grooves in an outer surface of a substrate. Each groove has a base and extends at least partially along the outer surface. A sacrificial filler is deposited within the groove, a second filler is deposited over the sacrificial filler, and a coating is disposed over at least a portion of the outer surface and over the second filler. The method further includes removing the sacrificial filler and at least partially removing the second filler from the groove(s), to define one or more channels for cooling the component.

Abstract: Gas turbine engine turbine blade includes a silicon-modified aluminide coating on at least an under platform region formed from a slurry composition being substantially free of hexavalent chromium. The silicon-modified aluminide coating provides oxidation resistance comparable to PtAl coatings without adding a weight penalty.

Abstract: The disclosure relates generally to methods for platinum recovery from articles. More specifically, the disclosure relates to methods for recovering platinum from gas engine components.

Abstract: Methods of fabricating coated components using multiple types of fillers are provided. One method comprises forming one or more grooves in an outer surface of a substrate. Each groove has a base and extends at least partially along the outer surface of the substrate. The method further includes disposing a sacrificial filler within the groove(s), disposing a permanent filler over the sacrificial filler, disposing a coating over at least a portion of the substrate and over the permanent filler, and removing the first sacrificial filler from the groove(s), to define one or more channels for cooling the component. A component with a permanent filler is also provided.

Abstract: Methods of fabricating coated components using multiple types of fillers are provided. One method comprises forming one or more grooves in an outer surface of a substrate. Each groove has a base and extends at least partially along the outer surface. A sacrificial filler is deposited within the groove, a second filler is deposited over the sacrificial filler, and a coating is disposed over at least a portion of the outer surface and over the second filler. The method further includes removing the sacrificial filler and at least partially removing the second filler from the groove(s), to define one or more channels for cooling the component.

Abstract: A casting process and apparatus for producing directionally-solidified castings, and castings produced therewith. The process entails applying a facecoat slurry to a surface within a mold cavity to form a continuous solid facecoat on the surface, introducing a molten metal alloy into the mold cavity so that the molten metal alloy contacts the facecoat, and then immersing the mold in a liquid coolant to cool and solidify the molten metal alloy and form a casting of the metal alloy, during which an oxide layer forms on the casting surface. The facecoat is sufficiently adherent to the oxide layer such that at least a portion of the facecoat detaches from the mold surface and remains tightly adhered to the casting surface in the event the casting contracts during cooling. The facecoat contains at least 60 weight percent of a first phase of yttria, and the balance of the facecoat is a binder phase of an inorganic material.

Abstract: The present disclosure is directed to the use and manufacture of cooling features within a component used in a hot gas path, such as within a turbine. In one embodiment, channels are formed within an external surface of the component and filled with a removable material. The external surface and channels may then be coated with one or more layers, such as a structural layer and/or top coat. The removable material may then be removed to leave the channels free of the removable material.

Abstract: A braze formulation includes a novel promoter and a metal filler. The promoter includes a blend of potassium tetrafluoroaluminate and potassium tetrafluoroborate. The braze may be used for repairing cracks in a substrate. The braze has a low melt point, removes oxides from within cracks and has improved penetration into cracks for repair.

Abstract: Slurry coating composition for selectively enriching surface regions of a metal-based substrate, for example, the under-platform regions of a turbine blade, with chromium. The slurry coating composition contains metallic chromium, optionally metallic aluminum in a lesser amount by weight than chromium, and optionally other constituents. The composition further includes colloidal silica, and may also include one or more additional constituents, though in any event the composition is substantially free of hexavalent chromium and sources thereof. The coating composition can be used in a process that entails applying the coating composition to a surface region to form a slurry coating, and then heating the coating to remove any volatile components of the coating composition and thereafter cause diffusion of chromium from the coating into the surface region to form a chromium-rich diffusion coating.

Abstract: A slurry suitable for forming facecoats, facecoats formed by such a slurry, and processes using such facecoats. The slurry is formed of a particulate refractory material, an aqueous suspension containing a particulate inorganic binder, a thixotropic organic binder, a dispersant, and possibly optional constituents excluding particulate refractory materials and inorganic binders. The particulate refractory material constitutes at least about 60 weight percent of the slurry and consists essentially of yttria. The aqueous suspension containing the particulate inorganic binder constitutes at most about 35 weight percent of the facecoat slurry. The dispersant is present in the slurry in an amount sufficient to stabilize the slurry at a pH of up to about 10, and has the general formula Hx[N(CH2)yOH]z, where x has a value of 0, 1 or 2, y has a value of 1 to 8, and z=3?x.

Abstract: A method for cracking hydrocarbon, comprises: providing steam and hydrocarbon; and feeding steam and hydrocarbon into a reactor accessible to hydrocarbon and comprising a perovskite material of formula AaBbCcDdO3-?, wherein 0<a<1.2, 0?b?1.2, 0.9<a+b?1.2, 0<c<1.2, 0?d?1.2, 0.9<c+d?1.2, ?0.5<?<0.

Abstract: A method and aqueous composition are provided for removing at least a portion of a coating from the surface of a substrate. The coating comprises an insulative material, and is contacted with an aqueous composition. The aqueous composition comprises dimethyl formamide.

Abstract: A method for selectively removing an aluminum-poor overlay coating from a substrate of a component, which as a result of its low aluminum content is highly resistant to a selective stripping solution. The method entails diffusing aluminum into the overlay coating to form an aluminum-infused overlay coating having an increased aluminum level in at least an outer surface thereof. The diffusion step is carried out so that the increased aluminum level is sufficient to render the aluminum-infused overlay coating removable by selective stripping. The outer surface of the aluminum-infused overlay coating is then contacted with an aqueous composition to remove the aluminum-infused overlay coating from the substrate. The aqueous composition includes at least one acid having the formula HxAF6, and/or precursors thereof, wherein A is Si, Ge, Ti, Zr, Al, and/or Ga, and x is from 1 to 6.

Abstract: The present invention provides a method for preparing an electroless nickel coating composition that includes (a) coating a substrate with an electroless nickel coating to provide a coated substrate; and (b) subjecting the coated substrate to a heating protocol comprising heating to a temperature in a range from about 550° C. to about 700° C. for a period of from about 7 to about 30 hours. An article made from the method is also provided.