A stirring device includes a stirring unit, a gas supplying unit, and a feeding unit. The stirring unit includes a drive mechanism and a shaft member. The shaft member includes a hollow rotary shaft coupled to be driven by the drive mechanism to rotate, and a stirring head coupled to rotate with the hollow rotary shaft. The gas supplying unit includes a gas supply, and a piping member fluidly communicating with the (gas supply and the shaft member. The feeding unit includes a storage tank and a feeding tube fluidly communicating with the storage tank and the shaft member.

Provided herein are nanocrystalline materials comprising, e.g., a matrix including one or more metals; and nanostructures dispersed in the matrix, wherein the matrix is polycrystalline and includes grains having an average size of about 1μm or less. Also provided herein are manufacturing methods of a nanocrystalline materials.

A method and apparatus for producing metal matrix nanocomposites is disclosed. The method may include obtaining a nanodispersion by dispersing a plurality of nanoparticles into an inert gas within a dispersion chamber. Dispersing the plurality of nanoparticles into the inert gas may include injecting a pressurized stream of the inert gas into the dispersion chamber, and mechanically mixing the inert gas and the plurality of nanoparticles. The method may further include injecting the nanodispersion into a volume of molten metal, obtaining a molten mixture by mechanically mixing the nanodispersion with the volume of molten metal, and applying a casting process on the molten mixture by transferring the molten mixture into a die.

The present disclosure provides a metal-ceramic composite structure and a fabrication method thereof. The metal-ceramic composite structure includes a ceramic substrate having a groove on a surface thereof; a metal member filled in the groove, including a main body made of zirconium base alloy, and a reinforcing material dispersed in the main body and selected from at least one of W, Mo, Ni, Cr, stainless steel, WC, TiC, SiC, ZrC, ZrO.sub.2, BN, Si.sub.3N.sub.4, TiN and Al.sub.2O.sub.3; a luminance value L of the metal member surface is in a range of 36.92-44.07 under a LAB Chroma system.

The present disclosure provides a metal-ceramic composite structure and a fabrication method thereof. The metal-ceramic composite structure includes a ceramic substrate having a groove on a surface thereof; a metal member filled in the groove, including a main body made of zirconium base alloy, and a reinforcing material dispersed in the main body and selected from at least one of W, Mo, Ni, Cr, stainless steel, WC, TiC, SiC, ZrC, ZrO.sub.2, BN, Si.sub.3N.sub.4, TiN and Al.sub.2O.sub.3; a luminance value L of the metal member surface is in a range of 36.92-44.07 under a LAB Chroma system.

Provided is aluminum (Al) alloy foam including an Al alloy matrix containing magnesium (Mg), and hollow ceramic spheres dispersed in the Al alloy matrix, wherein a reaction layer including a MgAl composite oxide is formed at an interface where the Al alloy matrix is in contact with the hollow ceramic spheres, and wherein a density of the Al alloy foam may be higher at a surface region of the Al alloy foam compared to a middle region of the Al alloy foam.

Metal-nanoparticle composites, such as metal-boron nitride nanoparticle composites, and methods of manufacturing the same are provided. Ultrasonic casting techniques can be used to achieve uniform dispersion of nanoparticles, such as boron nitride nanotubes (BNNTs) in a metal matrix, such as aluminum. The BNNTs can be incorporated into the melt of the metal, and ultrasonic treatment can then be applied.

Metal-nanoparticle composites, such as metal-boron nitride nanoparticle composites, and methods of manufacturing the same are provided. Ultrasonic casting techniques can be used to achieve uniform dispersion of nanoparticles, such as boron nitride nanotubes (BNNTs) in a metal matrix, such as aluminum. The BNNTs can be incorporated into the melt of the metal, and ultrasonic treatment can then be applied.

The present invention relates to a preparation method of a lithium-containing magnesium/aluminum matrix composite. The preparation method is performed according to the following steps: (1) preparing magnesium ingots or aluminum ingots, preparing lithium metal, and preparing flux and reinforcements; (2) heating the flux to prepare flux melt, and adding the reinforcements to the flux melt to prepare a liquid-solid mixture; (3) pouring the liquid-solid mixture in a normal-temperature crucible, and performing cooling to obtain a precursor; (4) preheating a crucible, adding raw materials, and performing melting to form a raw material melt; (5) controlling a temperature of the raw material melt to 973-993K, adding the lithium metal, performing stirring, adding the precursor, performing stirring and mixing, raising temperature to 993-1013K, and performing standing; and (6) scumming operation should be carried out, and performing temperature casting on composite melt.

A system of obtaining an aluminium melt including SiC particles for use when moulding vehicle parts, e.g. brake disks, the system comprises a pre-processing tank (2), configured to receive SiC particles and to apply a pre-processing procedure to pre-process the SiC particles; a SiC particle transport member (4) configured to transport the pre-processed SiC particles from the pre-processing tank (2) to a crucible (6) of a melting furnace device (8), and the melting furnace device (8) is configured to receive and melt solid aluminium, e.g. aluminium slabs, and to hold an aluminium melt (10) and to receive said pre-processed SiC particles (12). The system also comprises a tube-like SiC particle mixing arrangement (14) defining and enclosing an elongated mixing chamber (16), the mixing arrangement (14) is configured to be mounted in said crucible (6) and structured to receive into said mixing chamber (16) said pre-processed SiC particles (12) via a first inlet (18) and said aluminium melt (10) via at least one second inlet (20), and to apply a mixing procedure by rotating a rotatable mixing member (22) arranged in said mixing chamber (16) about said longitudinal axis A, wherein said pre-processed SiC particles are mixed together with the aluminium melt in said mixing chamber. The mixing arrangement (14) is provided with at least one outlet (26) to feed out the mixture from said mixing chamber into said crucible.