The present invention relates to a method for preparing ferrite/reducing metal composite particles and a method for preparing a high temperature resistant stealth coating based on 3D laser printing, belonging to the technical field of preparation of absorbing coatings. The present invention aims to solve the problems that an existing high-temperature absorbing coating has insufficient coating/matrix bonding force, the microstructure of the coating is difficult to control, and electromagnetic properties cannot be ensured. In the present invention, nano ferrite powder and nano reducing metal powder are prepared into composite particles by a mixing granulation process. In a sealed preparation chamber of a 3D printing device, composite particles are subjected to laser-induced in-situ reaction on the surface of a substrate to prepare a high temperature resistant stealth coating. The present invention is applied to high temperature resistance and stealth of components and prevention and control of electromagnetic pollution.

A hardfacing alloy satisfies the following condition when the hardfacing alloy as a whole is 100 mass % (also simply referred to as %, hereinafter), Ni: 10-25%, Si: 1-3%, Fe: 3-18%, the total of one or more elements of Mo, W, and Nb: 6.5-20%, and the balance: Cu and impurities. In particular, it preferably satisfies Fe+2Mo22.6(%), Mo equivalent/Fe1.17, and Mo equivalent=Mo+0.522W+1.033Nb. In a hardfacing part composed of the hardfacing alloy, coarse hard particles are formed to ensure the wear resistance, and a soft phase present in the hard particles ensures the machinability. This may be understood as a raw material powder for hardfacing treatment and may also be understood as a hardfacing member in which a hardfacing part is formed on a base material using the raw material powder.

A hardfacing alloy satisfies the following condition when the hardfacing alloy as a whole is 100 mass % (also simply referred to as %, hereinafter), Ni: 10-25%, Si: 1-3%, Fe: 3-18%, the total of one or more elements of Mo, W, and Nb: 6.5-20%, and the balance: Cu and impurities. In particular, it preferably satisfies Fe+2Mo22.6(%), Mo equivalent/Fe1.17, and Mo equivalent=Mo+0.522W+1.033Nb. In a hardfacing part composed of the hardfacing alloy, coarse hard particles are formed to ensure the wear resistance, and a soft phase present in the hard particles ensures the machinability. This may be understood as a raw material powder for hardfacing treatment and may also be understood as a hardfacing member in which a hardfacing part is formed on a base material using the raw material powder.

A method of forming a ferrous metal case-hardened layer using additive manufacturing. The method includes delivering, by a material delivery device, a filler material to a surface of a substrate. The substrate includes a first ferrous metal. The filler material includes a second ferrous metal and a carbon-based material. The method also includes directing, by an energy delivery device, an energy toward a volume of the filler material to join at least some of the filler material to the substrate to form a component.

There is provided a chain apparatus made at least in part by additive manufacturing. The apparatus includes a pair of spaced-apart annular members. The apparatus includes an elongate member coupled to and extending between the annular members. At least one of the members comprises one or more self-draining internal chambers to allow for removal of residual material therefrom.

A method of additive manufacturing is provided. The method comprises first forming a part injecting a first gas into a build chamber and depositing a first layer of metal-containing powder over a build platform. The first layer of powder is melted a laser and then cooled. The above steps can be optionally repeated to build additional layers. A coating is formed on the surface of the part by injecting a second, different gas into the chamber over the surface of the part. A portion of the surface is selectively heated with a second laser device, thereby chemically altering the heated portion to form the coating. After forming the coating, an additional aliquot of the first gas is injected into the chamber while venting the second gas from the chamber.

A method to form a metal matrix composite reinforced with eggshell (ES). The method includes preparing an ES powder, blending and milling the ES powder with at least one metal powder selected from the group consisting of magnesium (Mg), zirconium (Zr) to form a powder mixture, compacting and sintering the powder mixture to form the metal matrix composite. In addition, a MgZr-ES metal matrix composite with improved corrosion resistance, having an amount of magnesium from 95 to 97 wt. %, an amount of zirconium from 1 to 2 wt. %, and an amount of ES from 1 to 4 wt. %, may be used for biomedical applications.

A method for creating an object by consolidating a powder includes providing a composite including a first material arrange to form a porous structure and a second, sacrificial, material surrounding the first material. The composite may be surrounded with a powder and an intermediate objecting may be formed having a dense part bonded to the composite by densifying and bonding the powder to the composite in a single process. The second material may be removed from the intermediate object to from the object, which may include the porous structure and the dense part bonded to the porous structure.

The present disclosure relates to a fiber-reinforced copper-based brake pad for high-speed railway train, and preparation and friction braking performance thereof. The fiber-reinforced copper-based brake pad for high-speed railway train comprises 80-98.5 wt. % metal powder, 1-15 wt. % non-metal powder and 0.5-5 wt. % fiber component. In addition, some components are added in a specific proportion to achieve optimal performance. The copper-based powder metallurgy brake pad is obtained by powder mixing, cold-pressing and sintering with constant pressure. The friction braking performance of the obtained brake pad is tested according to a braking procedure consisting of three stages, i.e., the first stage with low-pressure and low-speed, the second stage with high-pressure high-speed and the continuous emergency braking third stage with high-pressure and high-speed. The brake pad has advantages including higher and more stable friction coefficient, higher fade and wear resistance and slighter damage to brake disc at high speeds.

Systems and methods include a computer-implemented method for manufacturing a binder for spraying onto tools. A binder is manufactured for binding compacts onto a tool substrate. The binder is designed to provide a coating strength on the tool substrate. The binder includes: a metal selected from iron (Fe), cobalt (Co), and nickel (Ni); an alloy including the metal selected from Fe, Co, and Ni; or a refractory alloy selected from tungsten, tantalum (Ta), molybdenum (Mo), and niobium (Nb). An ultra-high-pressure, high-temperature operation is performed on pure wurtzite boron nitride (w-BN) powder to synthesize w-BN and cubic boron nitride (c-BN) compact. A binder-compact mixture is produced by turbulently mixing the binder with the compact in a mixer within a vacuum. The binder-compact mixture is thermally sprayed onto a tool substrate to coat the tool.