A Ni-based alloy flux-cored wire includes the contents of Mn and Nb that are adjusted so that, from the wire, it is possible to obtain a weld metal having an excellent bead shape, good arc stability, spattering inhibition effect, good strength, good defect resistance, and good crack resistance. The Ni-based alloy flux-cored wire produces a weld metal having an excellent bead shape in multiple position welding of Ni-based alloy, 9% Ni steel, and high corrosion-resistance austenitic stainless steel, and an effect of producing a weld metal having good strength, defect resistance, and crack resistance.

A composition of a nickel-based alloy mixture which can be used for welding via especially liquid metal deposition or as a powder bed of an additive manufacturing method. The metallic powder mixture includes a cobalt (Co) or nickel (Ni) based super alloy, a NiCoCrAlY—X-composition wherein X=Silicon (Si), Tantalum (Ta), Rhenium (Re) and/or Iron (Fe), a metallic braze material, wherein the melting point of the braze material is at least 10K lower than the melting point of the cobalt (Co) or nickel (Ni) based superalloy.

A superalloy powder mixture is provided for use with additive manufacturing or welding metal components or portions thereof. The superalloy powder mixture includes at least 51% by weight a high melt superalloy powder and at least 5% by weight a low melt superalloy powder. The low melt superalloy powder may have a solidus temperature lower than the solidus temperature of the high melt superalloy powder by between 50° C. and 220° C. Each of the high melt superalloy powder, the low melt superalloy powder, and the superalloy powder mixture may have a nickel content by weight greater than 40% and may have an aluminum content by weight of greater than 1.5%. The low melt superalloy powder may include at least 5% by weight of tantalum, and the high melt superalloy powder may include less than half the content by weight percent of tantalum compared to the content by weight percent of tantalum in the low melt superalloy powder.

A method is provided that facilitates additive manufacturing a superalloy component using a liquid assisted additive manufacturing process. The method includes successively depositing and fusing together layers of a superalloy powder mixture comprising a high melt superalloy powder and a low melt superalloy powder to build up an additive portion of the superalloy component. The method may further include heat treating the additive portion to form a homogenized base alloy of which the additive portion is comprised, which base alloy has a chemistry defined by the superalloy powder mixture. Each of the high melt superalloy powder, the low melt superalloy powder, and the superalloy powder mixture may have a nickel content by weight greater than 40% and have an aluminum content by weight of greater than 1.5%. The low melt superalloy powder may include at least 5% by weight of tantalum, and the high melt superalloy powder may include less than half the content by weight percent of tantalum compared to the content by weight percent of tantalum in the low melt superalloy powder.

A high melt superalloy powder mixture is provided for use with additive manufacturing or welding metal components or portions thereof. The high melt superalloy powder may include by weight about 7.7% to about 18% chromium, about 10.6% to about 11% cobalt, about 4.5% to about 6.5% aluminum, about 10.6% to about 11% tungsten, about 0.3% to about 0.55% molybdenum, about 0.05% to about 0.08% carbon, and at least 40% nickel.

A wire is provided for additive manufacturing a superalloy component using a liquid assisted additive manufacturing process. The wire has an elongated body that includes therein a superalloy powder mixture including at least 51% by weight a high melt superalloy powder and at least 5% by weight a low melt superalloy powder. The low melt superalloy powder may have a solidus temperature lower than the solidus temperature of the high melt superalloy powder by between 50° C. and 220° C. Each of the high melt superalloy powder, the low melt superalloy powder, and the superalloy powder mixture may have an aluminum content by weight of greater than 1.5%. The low melt superalloy powder may include at least 5% by weight of tantalum, and the high melt superalloy powder may include less than half the content by weight percent of tantalum compared to the content by weight percent of tantalum in the low melt superalloy powder.

Properties and performance of weld material between metals in a weldment is controlled by modifying one or more of the nitrogen content and the carbon content to produce carbide (e.g. MC-type), nitride and/or complex carbide/nitride (e.g. MX-type) type precipitates. Fusion welding includes (i) adjusting shield gas composition to increase nitrogen/carbon gas and nitride/carbide species, (ii) adjusting composition of nitrogen/carbon in materials that participate in molten welding processes, (iii) direct addition of nitrides/carbides (e.g. powder form), controlled addition of nitride/carbide forming elements (e.g. Ti, Al), or addition of elements that increase/impede solubility of nitrogen/carbon or nitride/carbide promoting elements (e.g. Mn), and (iv) other processes, such as use of fluxes and additive materials. Weld materials have improved resistance to different cracking mechanisms (e.g., hot cracking mechanisms and solid state cracking mechanisms) and improved tensile related mechanical properties.

A composition of a nickel based alloy mixture which can be used for welding via especially liquid metal deposition or as a powder bed of an additive manufacturing method. A metallic powder mixture includes (in wt %): a cobalt (Co) or nickel (Ni) based super alloy with a content of 20% to 60%, a NiCoCrAlY-composition with a content of 70% to 30% and a metallic braze material with a content between 10% to 5%. The melting point of the braze material is at least 10K lower than the melting point of the nickel or cobalt based superalloy.

A method of repairing an airfoil is provided. The method includes providing an airfoil with a damaged section and removing the damaged section by machining or cutting an upper section of the airfoil. A replacement section is configured to mate with an upper surface of the airfoil. A presintered preform is provided to join the airfoil and the replacement sections through a resistance brazing process. The presintered preform is configured to mate with the upper surface of the airfoil and a lower surface of the replacement section and inserted between this upper surface and lower surface, creating a stacked airfoil comprising three mated sections in abutting contact. The stacked airfoil is resistance brazed such that only the braze material of the presintered preform melts and the upper surface of the airfoil and the lower surface of the replacement section remain below the grain boundary temperature of the material of the airfoil.

A weld filler is proposed which significantly improves the weldability of some nickel-based superalloys and includes the following constituents (in wt %): 11.2%-15.6% chromium (Cr), 9.6%-11.4% cobalt (Co) 2.4%-5.0%, molybdenum (Mo) 0.1%-3.3%, 4.4%-7.5% tungsten (W), 1.4%-2.6% tantalum (Ta), 3.0%-4.8% aluminum (Al), 0.4-1.0% titanium (Ti), 0.07%-0.08% carbon (C), 0.5%-1.4% hafnium (Hf), trace elements, and remainder nickel. A method is also provided. The method includes providing a nickel-based substrate to weld, applying a ductile weld filler having a closely matched coefficient of thermal expansion to a surface of the substrate, applying heat to melt the weld filler to form molten weld filler, welding the substrate with the weld filler at ambient temperature, and resolidifying the molten weld filler to form a solidified joint material.