Abstract: A reduction casting method includes the steps of: allowing a metallic gas and a reactive gas to react with each other to generate a reducing compound; introducing the thus-generated reducing compound into a cavity of a molding die 11; and reducing an oxide film formed on a surface of a molten metal by the reducing compound to cast a cast product. The reduction casting method uses a non-reactive gas as a carrier gas when the metallic gas is introduced into the cavity, in which a flow quantity of the non-reactive gas is allowed to be from one sixth to twice that of the reactive gas.
Abstract: A reduction casting method includes the steps of: pouring a molten metal into a cavity of a molding die; and performing casting while reducing an oxide film formed on a surface of the molten metal by allowing the molten metal and a reducing substance to come into contact with each other in the cavity. On this occasion, the molten metal is poured into the cavity in a state in which the molding die is forcibly cooled by a cooling device, thereby being rapidly cooled. Further, on this occasion, a solidification speed at which the molten metal is rapidly cooled is allowed to be 600° C./min or more. Still further, on this occasion, the molten metal is filled into the cavity in a filling time of from 1.0 second to 9.0 seconds.
Abstract: A process for casting and preparing an ingot of a beta-phase NiAl-based material, particularly for use in PVD coating processes. The method entails melting a nickel-aluminum composition having an aluminum content below that required for stoichiometric beta-phase NiAl intermetallic so as to form a melt that includes nickel and Ni3Al. Aluminum is then added to the melt, causing an exothermic reaction between nickel and aluminum as the melt equilibrium shifts from Ni3Al to NiAl. However, the aluminum is added at a rate sufficiently low to avoid a violent exothermic reaction. The addition of aluminum continues until sufficient aluminum has been added to the melt to yield a beta-phase NiAl-based material. The beta-phase NiAl-based material is then solidified to form an ingot, which is then heated and pressed to close porosity and homogenize the microstructure of the ingot.
Abstract: A method of minimizing the size of primary Si in Al—Si alloy which includes a step of adding P to molten Al—Si alloy, a step of contacting a metal substrate plated with Zn or a copper substrate, and a step of removing the substrate from the molten Al—Si alloy.
Type:
Grant
Filed:
March 5, 2002
Date of Patent:
April 29, 2003
Assignees:
Tozuka-Tendo Co., Ltd, Metal Science Ltd.
Abstract: The invention relates to a method of producing objects of cast iron containing compacted (vermicular) graphite crystals, by preparing a cast iron melt having substantially a carbon content at the desired final level and a silicon content below the desired final value, so that the equilibrium temperature (TE) for the reaction between carbon and SiO2 falls near 1400° C., and adjusting the temperature of the melt (TM) to a value between the equilibrium temperature (TE) and the “boiling temperature” (TB), to allow absorption of oxygen by the melt to a level exceeding the desired level at the time the melt is poured into a mold, adding the required amount of silicon, and thereafter reducing the oxygen content by addition of magnesium or magnesium containing material, preferably a FeSiMg-alloy to an oxygen level of 10 to 20 ppm oxygen in liquid solution, and forming particles of magnesium silicates as well as cast objects obtained by the method.
Abstract: An iron based alloy material for a thixocasting process and a method for casting the material which extends the service life of dies by inhibiting solidification contraction, and in which casting defects such as size variations and cracks can be inhibited. The material comprises 1.6 wt %≦C≦2.5 wt % and 3.0 wt %<Si≦5.5 wt %, and a carbon equivalent (the value of CE) defined as “C(wt %)+1/3Si(wt %)” of 2.9 to 3.5. This material is made to be in a half-melted state with 35 to 50 wt % of a solid phase to be cast under a pressure load.
Abstract: An apparatus and method for casting metallic components is disclosed. The apparatus has a vertical parting line and a gate configuration which reduces defects within the cast components.
Abstract: A method of adding boron to a tungsten, or tantalum, containing titanium aluminide alloy to form a boride dispersion in the tungsten, or tantalum, containing titanium aluminide. A molten tungsten, or tantalum, containing titanium aluminide alloy is formed and tungsten, or tantalum, boride is added to the molten tungsten, or tantalum, containing titanium aluminide alloy to form a molten mixture. The molten mixture is cooled and solidified to form a tungsten, or tantalum, containing titanium aluminide alloy having a uniform dispersion of tungsten, or tantalum, boride particles substantially without the formation of clusters of tungsten, or tantalum, boride. The titanium aluminide alloy comprises between 0.5 at % and 2.0 at % boron.
Type:
Grant
Filed:
June 30, 2000
Date of Patent:
December 3, 2002
Assignee:
Rolls-Royce plc
Inventors:
Paul A. Blenkinsop, Alastair B. Godfrey
Abstract: A method to minimize oxidation of metal during melting processes is provided, the method comprising placing solid phase metal into a furnace environ-ment, transforming the solid-phase metal into molten metal phase having a molten metal surface, and creating a barrier between the surface and the environment. Also provided is a method for isolating the surface of molten metal from its environment, the method comprising confining the molten metal to a controlled atmos-phere, and imposing a floating substrate between the surface and the atmosphere.
Type:
Grant
Filed:
August 4, 2000
Date of Patent:
November 26, 2002
Assignee:
The University of Chicago
Inventors:
John N. Hryn, Michael J. Pellin, Wallis F. Calaway, Jr., Jerry F. Moore, Gregory K. Krumdick
Abstract: A method of minimizing the size of primary Si in Al—Si alloy which comprises of a step of adding P to molten Al—Si alloy, a step of contacting a metal substrate plated with Zn or a copper substrate, and a step of removing the substrate from the molten Al—Si alloy.
Abstract: Method and investment shell mold for casting comprising introducing molten metallic material into an investment shell mold to fill a mold cavity and provide an upper surface of the molten metallic material above the mold cavity. An initially closed, destructible region of the mold then is broken to provide an entry opening through which exothermic material is placed on the upper surface of the molten metallic material to provide a source of molten metallic material to accommodate shrinkage of a casting as it solidifies in the mold cavity.
Abstract: Disclosed is a method for the determination of the form of graphite in spheroidal and compacted/vermicular cast irons comprising of the first step for collecting molten cast iron, measuring quantity of dissolved oxygen therein and confirming the effect of spherodizing or compacted/vermiculation of graphite in said molten cast iron, the second step for measuring eutectic temperature of said molten cast iron by thermal analyzing, and the third step for comparing said eutectic temperature with a threshold temperature at which said cast iron being separated spherodized graphite phase from compacted/vermiculation phase.
Abstract: The method of deoxidation casting of the present invention is capable of deoxidizing the oxide film formed on the surface of the molten metal, improving wettability to inner faces of a cavity of a casting die, and casting high quality products with high casting efficiency. The method of deoxidation casting of the present invention comprises the steps of: reacting a deoxidizing compound, which is made by reacting a metallic gas on a reactive gas, on a molten metal; and deoxidizing an oxide film on a surface of the molten metal.
Abstract: A method for quantitatively predicting and consequently minimizing the amount of critical phases such as eutectic Al2Cu formed during solidification of Al—Si—Cu alloys used in a vehicle engine component comprises developing a micromodel to simulate microstructure evolution in cast Al—Si or Al—Cu alloys. The micromodel is calibrated using experimental thermal analysis cooling curves and an optimization process. Microstructure evolution and cooling curves are simulated for a casting using the calibrated micromodel. Precipitation of critical phases such as Al2Cu in the casting is predicted as a function of solidification conditions. The model allows casting process variables to be varied with predictable results so that the casting process can be controlled via the micromodel.
Type:
Grant
Filed:
September 10, 1998
Date of Patent:
July 31, 2001
Assignee:
Ford Global Technologies, Inc
Inventors:
Nagendra Palle, Ravi Vijayaraghavan, Jacob Wesley Zindel, William Thomas Donlon, John Edmond Allison
Abstract: A method for nodulizing silicon crystals in casting Aluminum-(8-12%)Silicon alloys is described. An initial alloy melt is refined by addition of a master alloy containing elements of titanium, phosphorous, boron, zirconium and rare earths to the initial molten alloy, and then through conventional heat treatment and aging. Testing the alloys shows that the nodulized silicon crystals are blunted in shape and well distributed, resulting in a high resistance to wear and high ultimate tensile strength at room temperature and at 300 deg. C. Machinability of the Al-Si alloys is also greatly improved by the process.
Type:
Grant
Filed:
May 15, 2000
Date of Patent:
July 17, 2001
Inventors:
Hsien-Yang Yeh, Hen-Geul Yeh, Ru-Yao Wang, Wei-Hua Lu