This invention is concerned with the production of directionally solidified castings or ingots to eliminate casting defects such as macrosegregation and misoriented grain defects that occur in the blades for jet engines and industrial gas turbines. The mechanism of the occurrence of the above casting defects was clarified by the computer simulation system developed by this inventor, and it was found that, by strongly cooling the solid phase region and applying an axial static magnetic field, the heat pulses at the solidification interface due to convection of the liquid phase can be suppressed, and harmful lateral liquid flow in the solid-liquid coexisting phase can be suppressed by the synergistic effect of these two measures. This eliminates casting defects such as macrosegregation and misoriented grain defects, also refines the microstructure to produce high-quality products with excellent mechanical properties (creep strength). Regarding the strength of the static magnetic field, it was found that there is a range where the macrosegregation becomes minimum in a relatively low magnetic field range. This makes it possible to keep the required magnetic strength low, which significantly reduces the price of expensive superconducting coils. In addition, productivity can be improved by increasing the withdrawal speed.

This invention is concerned with the production of directionally solidified castings or ingots to eliminate casting defects such as macrosegregation and misoriented grain defects that occur in the blades for jet engines and industrial gas turbines. The mechanism of the occurrence of the above casting defects was clarified by the computer simulation system developed by this inventor, and it was found that, by strongly cooling the solid phase region and applying an axial static magnetic field, the heat pulses at the solidification interface due to convection of the liquid phase can be suppressed, and harmful lateral liquid flow in the solid-liquid coexisting phase can be suppressed by the synergistic effect of these two measures. This eliminates casting defects such as macrosegregation and misoriented grain defects, also refines the microstructure to produce high-quality products with excellent mechanical properties (creep strength). Regarding the strength of the static magnetic field, it was found that there is a range where the macrosegregation becomes minimum in a relatively low magnetic field range. This makes it possible to keep the required magnetic strength low, which significantly reduces the price of expensive superconducting coils. In addition, productivity can be improved by increasing the withdrawal speed.

Disclosure provides a two-segment electromagnet stirring member, and a two-segment electromagnet semi-solid die-casting apparatus including the same, and a die-casting method using the same. The two-segment electromagnet stirring member includes a plurality of magnetic field generation parts therein, and includes a first electromagnetic stirring part and a second electromagnetic stirring part separated from each other. The first electromagnetic stirring part and the second electromagnetic stirring part are coupled to each other in a ring shape to surround an outer circumferential surface of a sleeve to perform electromagnetic stirring to molten metal in the sleeve, and are coupled to each other so as to position the plurality of magnetic field generation parts at radially equal gaps around the sleeve.

A method of making a die cast part having high wear resistance is provided. The method comprises providing a mold and an insert pin. The mold comprises an interior surface defining a cavity. The mold comprises a bore formed through the interior surface. The insert pin has a magnetic core having a magnetic field and a barrier disposed about the magnetic core. The insert pin is disposed in the bore and extends into the cavity. The method comprises filling the mold with metallic material such that the metallic material is in contact with the insert pin to define a contact layer. The method comprises modifying iron content within the contact layer with the magnetic field to define an outer layer and an inner layer formed between the outer layer and the insert pin. The inner layer has 3-5 wt % Fe and the outer layer has 0.01-0.5 wt % Fe.

A method of making a die cast part having high wear resistance is provided. The method comprises providing a mold and an insert pin. The mold comprises an interior surface defining a cavity. The mold comprises a bore formed through the interior surface. The insert pin has a magnetic core having a magnetic field and a barrier disposed about the magnetic core. The insert pin is disposed in the bore and extends into the cavity. The method comprises filling the mold with metallic material such that the metallic material is in contact with the insert pin to define a contact layer. The method comprises modifying iron content within the contact layer with the magnetic field to define an outer layer and an inner layer formed between the outer layer and the insert pin. The inner layer has 3-5 wt % Fe and the outer layer has 0.01-0.5 wt % Fe.

This specification discloses an open mould conveyer casting apparatus for forming a metal ingot including: a conveyer for conveying one or more ingot moulds from at least a first location where an ingot mould receives a molten metal having an exposed surface, to a second location where the molten metal has partially or completely solidified into a metal ingot; one or more magnetic field applicators configured to apply a varying magnetic field to the molten metal in the ingot mould between the first location and the second location, the magnetic field being of a magnetic field strength to induce stirring within the molten metal. This specification also discloses an open mould conveyer casting method for forming a metal ingot including: filling an ingot mould with a molten metal, the molten metal in the mould having an exposed surface; solidifying the molten metal to form the metal ingot; and applying a varying magnetic field to the molten metal of a magnetic field strength and frequency to induce stirring within the molten metal during the step of solidifying the molten metal.

This specification discloses an open mould conveyer casting apparatus for forming a metal ingot including: a conveyer for conveying one or more ingot moulds from at least a first location where an ingot mould receives a molten metal having an exposed surface, to a second location where the molten metal has partially or completely solidified into a metal ingot; one or more magnetic field applicators configured to apply a varying magnetic field to the molten metal in the ingot mould between the first location and the second location, the magnetic field being of a magnetic field strength to induce stirring within the molten metal. This specification also discloses an open mould conveyer casting method for forming a metal ingot including: filling an ingot mould with a molten metal, the molten metal in the mould having an exposed surface; solidifying the molten metal to form the metal ingot; and applying a varying magnetic field to the molten metal of a magnetic field strength and frequency to induce stirring within the molten metal during the step of solidifying the molten metal.

A castable, moldable, or extrudable magnesium-based alloy that includes one or more insoluble additives. The insoluble additives can be used to enhance the mechanical properties of the structure, such as ductility and/or tensile strength. The final structure can be enhanced by heat treatment, as well as deformation processing such as extrusion, forging, or rolling, to further improve the strength of the final structure as compared to the non-enhanced structure. The magnesium-based composite has improved thermal and mechanical properties by the modification of grain boundary properties through the addition of insoluble nanoparticles to the magnesium alloys. The magnesium-based composite can have a thermal conductivity that is greater than 180 W/m-K, and/or ductility exceeding 15-20% elongation to failure.

A castable, moldable, or extrudable magnesium-based alloy that includes one or more insoluble additives. The insoluble additives can be used to enhance the mechanical properties of the structure, such as ductility and/or tensile strength. The final structure can be enhanced by heat treatment, as well as deformation processing such as extrusion, forging, or rolling, to further improve the strength of the final structure as compared to the non-enhanced structure. The magnesium-based composite has improved thermal and mechanical properties by the modification of grain boundary properties through the addition of insoluble nanoparticles to the magnesium alloys. The magnesium-based composite can have a thermal conductivity that is greater than 180 W/m-K, and/or ductility exceeding 15-20% elongation to failure.

Systems and methods are disclosed for using magnetic fields (e.g., changing magnetic fields) to control metal flow conditions during casting (e.g., casting of an ingot, billet, or slab). The magnetic fields can be introduced using rotating permanent magnets or electromagnets. The magnetic fields can be used to induce movement of the molten metal in a desired direction, such as in a rotating pattern around the surface of the molten sump. The magnetic fields can be used to induce metal flow conditions in the molten sump to increase homogeneity in the molten sump and resultant ingot.