Abstract:
Molten metal (6) in a furnace (5) and containing particles of solid material (not shown) in suspension is cast in moulds (1) conveyed continuously past the mould-filling station shown by a conveyor (4). To maintain the particles in suspension and keep the metal (6) homogeneous throughout the furnace (5), a paddle-wheel rotor (10) driven by a motor (13) keeps the molten metal in constant movement. A curved guide vane (14) is shaped, placed and oriented so as to divert some of the centrifugal flow from the rotor (10) towards the delivery tube (8) for the moulds (1), thus ensuring that the tube (8) is supplied with freshly-agitated metal.
Abstract:
A component is made, in regions, of a ceramic-metal composite material. A porous sacrificial body produced from ceramic precursors is filled with softened metal and/or a metallic alloy at a predeterminable filling temperature at or above the softening temperature of the filling metal and under superatmospheric pressure. The filled sacrificial body is heated to or above a reaction temperature which is higher than the filling temperature, where a reaction between the filling metal (FMe) and the metal of the ceramic of the sacrificial body (CMe) is carried out, forming the ceramic-metal composite material comprising a ceramic phase and a metallic phase. The ceramic phase comprises CMemBx and/or CMenCy and/or CMeoCN and FMepO3, and the metallic phase comprises an intermetallic compound of a metal of the ceramic (CMe) and a filling metal (FMe). The sacrificial body is filled with the filling metal (FMe) during pressure casting of the component. A shape at least close to the final shape of the component, comprising a filled sacrificial body and the intermediate element(s) free of the sacrificial body, is cast by the pressure casting tool, and the component after casting is complete is heated to or above the reaction temperature in the region of the sacrificial body.
Abstract:
An extrudable and weldable matrix alloy composite comprising: a) a base material metal of about 50 to 99.9% by weight, b) boron carbide or silicon carbide of about 0.1 to 50% by weight, c) less than about 3.0% by weight of at least one metal having an intermetallic phase temperature lower than the melting point of the base material metal, and d) a reinforcement agent of up to about 5% by weight.
Abstract:
An intermediate material is formed by coating at least a half of the surface of a function selecting material having at least one of physical property values that are different from those of a casting metal material forming a cast product with a coating metal material and the casting metal material is cast together with the intermediate material to form a composite body in casting the product.
Abstract:
A composite material having less than about 25 volume percent refractory particles in a metal matrix is concentrated to have about 37-45 volume percent refractory particles. The concentrating is accomplished by heating the composite material to melt the matrix, and then contacting the molten composite material to a porous element having an average pore size greater than that of the average particle size. A small pressure differential, on the order of about one atmosphere, is applied across the porous element, so that metal matrix material separates from the composite material and flows through the porous element. The particulate volume fraction in the composite material gradually increases. When the particulate volume fraction exceeds about 37 volume percent, the mass of composite material becomes semi-solid and freestanding. The resulting composite material may be further processed, as by forming to a useful shape or diluting with another matrix material.
Abstract:
A process for preparing a preform for use in a metal matrix composite, particularly for a magnesium metal composite, and a metal matrix composite, typically made by squeeze casting, using the preform. In the preform the reinforcing material typically is silicon carbide, boron nitride, carbon or graphite. The binder used in the preform is magnesium fluoride, which avoids the known problems which result from the high reactivity of magnesium metal with other binders, such as silica and alumina, which results in the formation of magnesium oxide in the reinforced composite. The presence of magnesium oxide crystals in the metal matrix adversely affects the properties of the composite.
Abstract:
The present invention relates to a novel method for forming cast metal matrix composite bodies. In particular, the present invention relates to a novel method for forming or recycling metal matrix composite bodies so as to render such bodies in a condition for casting or recasting as a cast metal matrix composite body. Specifically, a scrap metal matrix composite body and preferably a scrap cast metal matrix composite body is placed into a crucible, optionally along with unreinforced matrix metal and/or virgin metal matrix composite material. Whether the scrap and/or virgin materials are placed into the crucible in solid or molten form, the contents of the crucible are ultimately rendered molten to form a composite melt. A means for applying high shearing rates to the composite melt, such as an impeller rotating at high speed is immersed into the composite melt and the composite melt is sheared for a time sufficient to comminute any entrained inclusions such as entrapped oxide skins to a size at which such comminuted inclusions are substantially ameliorated in terms of their effect on the fluidity of the composite melt and the mechanical properties of the subsequent cast metal matrix composite bodies. Upon conclusion of the high intensity shearing process, the high power shearing apparatus is removed from the composite melt and the composite melt is cast using appropriate techniques for casting metal matrix composite material.
Abstract:
A metallic porous product is produced by applying a slurry of a mixture of skeleton constituent metal particles and property modifying particles to an inflammable porous foam, burning the inflammable porous foam having open pores by heat to provide a metallic skeleton structure, and sintering the metallic skeleton structure.
Abstract:
A process of making a vane for a rotary expansible chamber device, comprising the steps of: providing an open vane die having a die cavity, wherein said die cavity comprises a body cavity section corresponding to a body of the vane, a first tip cavity section corresponding to a first tip of the vane, and a second tip cavity section corresponding to a second tip of the vane; providing a preheated, porous carbon preform in the first tip cavity section of the vane die, the preform having a shape corresponding to at least a portion of the first tip cavity section; closing the vane die; injecting a castable admixture comprising a metal alloy and a plurality of inorganic particles into the die cavity and filling the vane die cavity with the injected admixture; impregnating the preform with the metal alloy of the injected admixture, substantially all of the inorganic particles from the injected admixture being filtered out by the preform as the admixture flows into the preform; allowing the castable admixture to solidify, whereby a vane is formed in the die cavity; and removing the vane from the die.
Abstract:
A carbonaceous material coated with a molybdenum carbide coating, the molybdenum carbide coating protecting the carbonaceous material against attack by molten metal while simultaneously providing a wetting action for the molten metal to infiltrate the carbonaceous material. The carbonaceous material is any suitable carbonaceous material such as diamond; graphite fibers, both continuous and discontinuous; carbon and graphite particulate; lampblack; and carbon-rich surfaces. The molybdenum carbide coating is produced by reacting a gaseous molybdenum compound with the surface of the carbonaceous material under a reducing atmosphere. The molybdenum carbide coated carbonaceous material is formed into a metal/carbonaceous material composite by being heated with the metal under an inert atmosphere until the molten metal infiltrates the molybdenum carbide coated carbonaceous material. The metals include copper, aluminum, magnesium, iron, nickel, cobalt, titanium, silver, gold, platinum, rhodium, tin, zinc, and alloys of these metals.