Systems, methods, and devices are disclosed for producing quantum particles (e.g., quantum dots) having a uniform size by vaporization of molten precursor droplets. More particularly, the present technology produces quantum dots by melting or liquefying solid and substantially pure precursor materials followed by production of uniformly sized droplets of molten precursor by use of a droplet maker into a microwave generated plasma torch.

According to one or more embodiments presently described, metal-containing particles may be made by a method that includes introducing a molten material into a reaction zone of a reactor system, passing a process gas into the reaction zone in a direction substantially tangential to a sidewall of the reaction zone, and contacting the process gas with the molten material in the reaction zone to form metal-containing particles. The molten material may be introduced into an upper portion of the reaction zone The reaction zone may include a substantially circular cross-section, and the molten metal may be introduced into the reaction zone in a laminar flow or as atomized particles.

Provided is a FeCrCuTiV high-entropy alloy powder for laser melting deposition manufacturing and a preparation method thereof, in percent by weight, the composition of the high-entropy alloy powder is: chromium 17-20%; copper 22-25%; titanium 16-19%; vanadium 17-20%; and ferrum 19-22%, wherein by utilizing the solid solution effect of alloying elements such as Ti, V and Cu of the high-entropy alloy, it can effectively alleviate the differences in thermal expansion coefficient, melting point, elastic modulus, etc. of the tungsten/steel or tungsten/copper heterogeneous interface, can reduce the residual stress level at the heterogeneous interface during the laser melting deposition manufacturing process and avoid the precipitation of Laves phase, and can meet the manufacturing requirements of tungsten/steel and tungsten/copper heterogeneous components for fusion reactors.

Provided is a FeCrCuTiV high-entropy alloy powder for laser melting deposition manufacturing and a preparation method thereof, in percent by weight, the composition of the high-entropy alloy powder is: chromium 17-20%; copper 22-25%; titanium 16-19%; vanadium 17-20%; and ferrum 19-22%, wherein by utilizing the solid solution effect of alloying elements such as Ti, V and Cu of the high-entropy alloy, it can effectively alleviate the differences in thermal expansion coefficient, melting point, elastic modulus, etc. of the tungsten/steel or tungsten/copper heterogeneous interface, can reduce the residual stress level at the heterogeneous interface during the laser melting deposition manufacturing process and avoid the precipitation of Laves phase, and can meet the manufacturing requirements of tungsten/steel and tungsten/copper heterogeneous components for fusion reactors.

The present invention is an atomization device for manufacturing metal powder by spraying a fluid to molten metal, said device comprising: a tundish into which the molten metal is poured and discharged from a discharge nozzle installed on a bottom part; fluid spray nozzles disposed below the tundish and spraying the fluid to the molten metal dropping from the tundish; a means for measuring a molten-metal surface height inside the tundish from an image obtained by imaging the inside of the tundish; and a means for, upon calculating an amount of the molten metal to be poured into the tundish from the molten-metal surface height, discharging the molten metal in such a manner that the height is maintained substantially constant. The interior of the tundish is formed in such a shape that the area of the molten-metal surface of the poured molten metal increases with height in the vertical direction.

There are provided an inexpensive copper powder, which has a low content of oxygen even it has a small particle diameter and which has a high shrinkage starting temperature when it is heated, and a method for producing the same. While a molten metal of copper heated to a temperature, which is higher than the melting point of copper by 250 to 700° C. (preferably 350 to 650° C. and more preferably 450 to 600° C.), is allowed to drop, a high-pressure water is sprayed onto the heated molten metal of copper in a non-oxidizing atmosphere (such as an atmosphere of nitrogen, argon, hydrogen or carbon monoxide) to rapidly cool and solidify the heated molten metal of copper to produce a copper powder which has an average particle diameter of 1 to 10 μm and a crystallite diameter Dx.sub.(200) of not less than 40 nm on (200) plane thereof, the content of oxygen in the copper powder being 0.7% by weight or less.

There are provided an inexpensive copper powder, which has a low content of oxygen even it has a small particle diameter and which has a high shrinkage starting temperature when it is heated, and a method for producing the same. While a molten metal of copper heated to a temperature, which is higher than the melting point of copper by 250 to 700° C. (preferably 350 to 650° C. and more preferably 450 to 600° C.), is allowed to drop, a high-pressure water is sprayed onto the heated molten metal of copper in a non-oxidizing atmosphere (such as an atmosphere of nitrogen, argon, hydrogen or carbon monoxide) to rapidly cool and solidify the heated molten metal of copper to produce a copper powder which has an average particle diameter of 1 to 10 μm and a crystallite diameter Dx.sub.(200) of not less than 40 nm on (200) plane thereof, the content of oxygen in the copper powder being 0.7% by weight or less.

A control method of a metal powder manufacturing apparatus, the metal powder manufacturing apparatus including a crucible housed in a dissolving tank, a molten metal nozzle attached to a bottom surface of the crucible, a plurality of gas injecting nozzles arranged on a periphery of the molten metal nozzle within a spray tank, and an orifice portion disposed in an upstream portion of a flow passage in the molten metal nozzle, an inside diameter of the orifice portion being equal to or more than 0.8 mm and equal to or less than 3 mm, the control method including: making a pressure (Ps) of the spray tank higher than a total value of pressure (Ph) acting on an upper end of the molten metal nozzle and a pressure (Pm) of the dissolving tank when a melting raw material is molten within the crucible; and making the pressure (Ps) of the spray tank lower than the total value of the pressure (Ph) acting on the upper end of the molten metal nozzle and the pressure (Pm) of the dissolving tank when a molten metal within the crucible is made to flow down into the spray tank via the molten metal nozzle.

A tilting melting hearth system (10) includes a tilting melting hearth (12) for melting a metal (14) into a molten metal (16) and a central processing unit (CPU) (18) for controlling the tilting melting hearth (12) having an automated hearth tilting program (20) configured to select a hearth tilt profile based on a weight (66A) of the molten metal (16) in the tilting melting hearth (12). The tilting melting hearth system (10) can also include an atomization die (38) in flow communication with the tilting melting hearth (12) for receiving a stream of molten metal (40) and generating a metal powder (42), or a casting die (46) for generating a casting (48) of the metal (14). The tilting melting hearth system (10) can be used to perform a method for recycling scrap metal by automatically determining the weight of the molten metal (16) in the tilting melting hearth (12).

A tilting melting hearth system (10) includes a tilting melting hearth (12) for melting a metal (14) into a molten metal (16) and a central processing unit (CPU) (18) for controlling the tilting melting hearth (12) having an automated hearth tilting program (20) configured to select a hearth tilt profile based on a weight (66A) of the molten metal (16) in the tilting melting hearth (12). The tilting melting hearth system (10) can also include an atomization die (38) in flow communication with the tilting melting hearth (12) for receiving a stream of molten metal (40) and generating a metal powder (42), or a casting die (46) for generating a casting (48) of the metal (14). The tilting melting hearth system (10) can be used to perform a method for recycling scrap metal by automatically determining the weight of the molten metal (16) in the tilting melting hearth (12).