Implementations provide gas atomized metal matrix composite (“GAMMC”)-based feedstock for cold spray additive manufacturing (“CSAM”) enabling complex structural repairs. The feedstock is prepared by arranging a metal matrix composite (MMC) material in a gas atomization system, wherein the MMC material includes metal particles and ceramic particles. The feedstock is further prepared by performing gas atomization of the MMC material using the gas atomization system to atomize the MMC material, and producing a feedstock powder comprised of metal particles that are embedded with the ceramic particles from the atomized MMC material. The GAMMC-based feedstock comprises metallic (for binding to the substrate of the damaged part) and ceramic (for reinforcement) particles bonded together such that the ceramic particles bond directly to and within the metallic particles. GAMMC-based feedstock strengthens the repaired part and prevents degradation of the mechanical properties of the repaired part below stock specifications.

A method for manufacturing a planet gear or a sun gear of a gearbox of a wind turbine includes forming a base of the planet gear via at least one of casting or forging. The base of the planet gear includes an inner circumferential surface and an outer circumferential surface. Therefore, at least one of the inner circumferential surface or the outer circumferential surface of the planet gear includes a plurality of net or near-net gear teeth. The method also includes applying a coating material to at least a portion of the base of the gear and at least a portion of the plurality of gear teeth of the gear via an additive manufacturing process so as to increase a hardness of the portions of the base and the plurality of gear teeth that includes the coating material.

Articles are manufactured using self-propagating high-temperature synthesis (SHS) reactions. Particulates including reactants can be blended to form a particulate blend. The particulate blend can be preformed. The preform article can be heated to a pre-heat temperature being below an auto-activation temperature and above a minimum compression activated synthesis temperature. Compressive stress can be exerted on the preform article at the pre-heat temperature to initiate the SHS reaction between the reactants and thereby form a product metallic compound. At approximately peak temperature, a flow stress of the product metallic compound can be exceeded to substantially reduce porosity and thereby form a shaped substantially dense article.

Provides a method for producing aluminum oxide powder by electrochemical dissolving aluminum salt, comprise: (A) providing an electrochemical device with an aluminum material as an anode and an acidic solution as an electrolyte; (B) accelerating the dissolution of the aluminum material by current pulse method to form an acidic aluminum salt solution; (C) neutralizing the acidic aluminum salt solution with a basic solution to form an aluminum hydroxide sol; (D) adding an additive in the aluminum hydroxide sol, filtering the aluminum hydroxide sol and drying to obtain aluminum hydroxide powder; (E) roasting the aluminum hydroxide powder to form micron scale γ-aluminum oxide powder. Combines the acidic aluminum salt method and the electrochemical dissolution method to improve the dissolving rate of the aluminum material and increase the output efficiency of the acidic aluminum salt, and obtaining micron scale γ-aluminum oxide powder.

Disclosed is a nano dispersion copper alloy with high air-tightness and low free oxygen content and a brief manufacturing process thereof, wherein alloy comprises the following components: Al.sub.2O.sub.3, Ca and La. The manufacturing process comprises the following steps of: preparing Cu—Al.sub.2O.sub.3 alloy powder by an internal oxidation method; mixing the Cu—Al.sub.2O.sub.3 alloy powder with Cu—Ca—La alloy powder; sheathing the mixed powder under protection of argon; performing hot extrusion and then rotary forging; vacuumizing the sheath after the rotary forging; and sealing and placing the sheath in a nitrogen atmosphere with a temperature of 450° C. to 550° C. and a pressure intensity of 40 Mpa to 60 Mpa for 3 hours to 5 hours. The dispersion copper prepared by the present disclosure has the advantages of low free oxygen content (≤15 ppm), high dimensional stability, good air-tightness and an air leakage rate≤1.0×10.sup.−10 Pa m.sup.3/s after hydrogen annealing.

The iron loss of a dust core is reduced. A dust core (1) includes soft magnetic metal particles (3) having an average particle size of 5 μm or more and 30 μm or less, and a particle boundary phase (6). The particle boundary phase (6) includes a polycrystalline compound containing Al (aluminum). When a sectional structure of the dust core (1) is observed, an area percentage of α-Al.sub.2O.sub.3 in the particle boundary phase (6) is 75% or less. An average thickness Ta of the particle boundary phase (6) is 10 nm or more and 300 nm or less. According to the present invention, the iron loss is reduced.

A method for the assembly of a metal part and a ceramic part, including the following steps: supplying a solid ceramic part of the alumina type; supplying a solid metal part, the metal being selected from platinum and tantalum, or an alloy including a majority of one of these metals; depositing at least one layer, called interface layer, on at least one of the solid parts, the interface layer containing magnesium oxide; bringing into contact the solid metal part and the solid ceramic part such that the interface layer is located between the solid parts; and hot densification under pressure of the solid parts brought into contact, to create a close bond between the solid parts and form a spinel from the interface layer. An electrical device, such as a capacitive sensor having a sensitive part produced according to the present method, is also provided.

A soft magnetic nanoparticle comprising an iron aluminide nanoalloy of the DO.sub.3 phase as a core encapsulated in an inert shell made of alumina.

In one aspect, methods of making freestanding metal matrix composite articles and alloy articles are described. A method of making a freestanding composite article described herein comprises disposing over a surface of the temporary substrate a layered assembly comprising a layer of infiltration metal or alloy and a hard particle layer formed of a flexible sheet comprising organic binder and the hard particles. The layered assembly is heated to infiltrate the hard particle layer with metal or alloy providing a metal matrix composite, and the metal matrix composite is separated from the temporary substrate. Further, a method of making a freestanding alloy article described herein comprises disposing over the surface of a temporary substrate a flexible sheet comprising organic binder and powder alloy and heating the sheet to provide a sintered alloy article. The sintered alloy article is then separated from the temporary substrate.

A system has a surface, a feedstock deposition head arranged to deposit a sinterable feedstock having a binder on the surface, a patterning system arranged adjacent the surface to change the feedstock surface energy according to a pattern to form selective surface energy patterns on the feedstock, a sintering-selectivity material deposition head arranged adjacent the feedstock deposition head to deposit sintering-selectivity fluid, the sintering-selectivity fluid selected to conform to the selective surface energy patterns, and a sintering chamber to sinter the feedstock after deposition of the anti-sintering agent. A method of forming three-dimensional objects includes depositing a, sinterable feedstock onto a surface, forming a surface energy pattern in the sinterable feedstock by pattern-wise debinding of the binder from the sinterable feedstock, depositing a sintering-selectivity fluid mixed with a solvent selected to cause the sintering-selectivity material to conform to the surface energy pattern, and sintering the feedstock.