This invention relates to the field of 3D metal printing, and more particularly to a method of rapidly melting metal for 3D metal printers by electromagnetic induction. This is a new cost-effective 3D metal printing method that enables direct heating and rapid melting of metals, higher energy conversion efficiency, higher deposition rates, smaller oxide, higher safety and controllability, faster printing, and larger-size metal components manufacturing.

To provide a single crystal production apparatus capable of efficiently producing a single crystal of relatively high quality, by cooling a melting zone, the device including: a heating part that forms the melting zone from a raw material by irradiation of light; and a supporting part that supports the melting zone in a non-contact manner.

An electric induction furnace for heating and melting electrically conductive materials is provided with a lining wear detection system that can detect replaceable furnace lining wear when the furnace is properly operated and maintained. In some embodiments of the invention the lining wear detection system utilizes an electrically conductive wire assemblage embedded in a wire assemblage refractory disposed between the replaceable lining and the furnace's induction coil.

The invention relates to an induction crucible furnace and to a magnetic return element for an induction crucible furnace. The induction crucible furnace has a corresponding coil and a plurality of magnetic return elements, which are designed in the form of individual units arranged on the outer lateral surface of the coil with peripheral spacing. In order to guide the magnetic flux produced by the coil, the magnetic return elements each have an assembly consisting of a plurality of elongate individual elements of magnetically permeable material that are electrically insulated from each other and extend parallel to the furnace axis. Said individual elements consist at least partially of bars, which are electrically insulated from each other and the longitudinal axes of which extend parallel to the furnace axis. In this way, both eddy currents that hit the assembly from the radial direction and eddy currents that hit the assembly with a transverse component are minimized.

An induction furnace comprising a upper furnace vessel; an induction coil positioned below the upper furnace vessel; and a melt-containing vessel positioned inside the induction coil and communicably connected to the upper furnace vessel, wherein the positioning of the melt-containing vessel inside the induction coil defines a gap between an outside surface of the melt-containing vessel and an inside surface of the induction coil. A system for direct-chill casting comprising at least one an induction furnace; at least one in-line filter operable to remove impurities in molten metal; at least one gas source coupled to a feed port associated with the gas; and at least one device for solidifying metal by casting. A method of cooling an induction furnace comprising introducing a gas into a gap between an induction coil and a melt-containing vessel positioned inside the induction coil; and circulating the gas through the gap.

A multi-section coil enhanced stirring system wherein only one of the coils is powered from a single-phase AC source to enhance the stirring of the metal.

A crucible device with temperature control design includes a crucible body, an induction coil unit, a nozzle flange body and a melt delivery tube and a temperature control unit. The induction coil unit surrounds the crucible body, provides a heat source during use, and is configured to enable a metal material to melt and produce a melt having a melting skull. The melt delivery tube is communicated via the nozzle flange body to a bottom of the crucible body and is configured to deliver the melt from the crucible body. The temperature control unit includes a microprocessor, a heater and a temperature sensor which are electrically coupled to each other, and are configured to control a curve of the melting skull to drop to a preset position.

An induction furnace comprising a upper furnace vessel; an induction coil positioned below the upper furnace vessel; and a melt-containing vessel positioned inside the induction coil and communicably connected to the upper furnace vessel, wherein the positioning of the melt-containing vessel inside the induction coil defines a gap between an outside surface of the melt-containing vessel and an inside surface of the induction coil. A system for direct-chill casting comprising at least one an induction furnace; at least one in-line filter operable to remove impurities in molten metal; at least one gas source coupled to a feed port associated with the gas; and at least one device for solidifying metal by casting. A method of cooling an induction furnace comprising introducing a gas into a gap between an induction coil and a melt-containing vessel positioned inside the induction coil; and circulating the gas through the gap.

Methods and apparatus for moving a molten metal are provided in which the electromagnetic inductor includes at least two pairs of electromagnetic pole pairs and in which a first magnetic field component is generated between one pole in a first electromagnetic pole pair and a second pole in a different electromagnetic pole pair, and in which a second magnetic field component is generated between the two poles in one or more electromagnetic pole pairs, the second magnetic field component thereby generating one or more eddy currents in the molten metal. Those eddy currents are generally parallel to the surface of the molten metal and so have greater magnitude and extent that eddy currents perpendicular to the surface. Such eddy currents provide useful additional movement to the molten metal, for instance for stirring purposes, particularly when the depth of molten metal is small.

Disclosed are embodiments of a vessel configured to contain a secondary magnetic induction field therein for melting materials, and methods of use thereof. The vessel can be used in an injection molding apparatus having an induction coil positioned adjacent to the vessel. The vessel can have a tubular body configured to substantially surround and receive a plunger tip. Longitudinal slots or gaps extend through the thickness of the body to allow and/or direct eddy currents into the vessel during application of an RF induction field from the coil. The body also includes temperature regulating lines configured to flow a liquid within. The temperature regulating lines can be provided to run longitudinally within the wall(s) of the body between its inner bore and outer surface(s). A flange may be provided at one end of the body to secure the body within an injection molding apparatus.