A ceramic-reinforced aluminum matrix composite is formed by contacting a molten aluminum-magnesium alloy with a permeable mass of ceramic material in the presence of a gas comprising from about 10 to 100% nitrogen, by volume, balance non-oxidizing gas, e.g., hydrogen or argon. Under these conditions, the molten alloy spontaneously infiltrates the ceramic mass under normal atmospheric pressures. A solid body of the alloy can be placed adjacent a permeable bedding of ceramic material, and brought to the molten state, preferably to at least about 700° C., in order to form the aluminum matrix composite by infiltration. In addition to magnesium, auxiliary alloying elements may be employed with aluminum. The resulting composite products may contain a discontinuous aluminum nitride phase in the aluminum matrix and/or an aluminum nitride external surface layer.

Metal matrix composites

A thermal transfer recording medium comprising a substrate and a hot-melt ink layer, provided on one surface of the substrate, and a back-coated layer, provided on the other surface of the substrate, said hot-melt ink layer comprising a polyether resin having a basic bisphenol structure and hydroxyl groups at the terminal ends thereof as a binder, and a colorant, said back-coated layer comprising a reaction product of a polyisocyanate and an amino-modified silicone oil, is disclosed. The thermal transfer recording medium of the present invention is capable of forming a transferred image of high quality substantially without being affected by the surface properties of the image receiving paper, and has a high stability.

Thermal transfer recording medium

Metal matrix composites consist of a metal or an alloy as the continuous matrix and a reinforcement that can be particle, short fiber or whisker, or continuous fiber. In this chapter, we first describe important techniques to process metal matrix composites, then we describe the interface region and its characteristics, properties of different metal matrix composites, and finally, we summarize different applications of metal matrix composites.

Metal Matrix Composites

A semiconductor memory device comprises memory cells, a bitline connected to the memory cells, a read circuit including a precharge circuit, and a first transistor connected between the bitline and the read circuit, wherein a first voltage is applied to a gate of the first transistor when the precharge circuit precharges the bitline, and a second voltage which is different from the first voltage is applied to the gate of the first transistor when the read circuit senses a change in a voltage of the bitline.

Semiconductor memory device.

A metal matrix composite comprises randomly-­oriented inorganic oxide fibres of density below 3 g/ml embedded in a metal matrix material such as a light metal, for example aluminium or magnesium or an alloy thereof. In a particular embodiment the fibres are of density l.8 to 2.5 g/ml and preferably are of mean diameter from 2 to l0 microns. The composite can be made by liquid infiltration of a fibre preform comprising the fibres bound together with an inorganic or an organic binder or by extrusion of a mixture of the fibres and a powdered metal matrix material.

Fibre-reinforced metal matrix composites

Fiber reinforced metal type composite material with high purity aluminum alloy containing magnesium as matrix metal

In producing a metal base composite material by first producing a porous preform from a reinforcing material such as short fibers, whisker, particles or mixtures thereof, and secondly infiltrating a molten matrix .metal into the interstices of the porous preform, fine pieces of a third material having good affinity to the molten matrix metal are mixed in the porous preform in the process of producing the preform, and at least a part of the preform is contacted with a molten mass of the matrix metal so that the molten matrix metal infiltrates into the interstices of the porous preform with no substantial pressure being applied thereto.

Method of producing metal base composite material under promotion of matrix metal infiltration by fine pieces of third material

In an aluminum alloy composite material including an aluminum alloy matrix and a reinforcing material such as fibers, whisker or particles, intermetallic compounds made of Al and at least one selected from a group of Fe, Ni, Co, Cr, Cu, Mn, Mo, V, W, Ta, Nb, Ti and Zr are finely dispersed in the matrix existing among reinforcing material elements so as to maintain rigidity of the matrix alloy necessary to support the reinforcing material elements at high temperature. Optimum shapes and volumetric density of such intermetallic compounds are experimentally obtained.

Aluminum alloy composite material with intermetallic compound finely dispersed in matrix among reinforcing elements

A method of producing a composite material from porous reinforcing material and molten matrix metal. First the porous reinforcing material is heated up to a temperature substantially above melting point of the matrix metal. Then the molten matrix metal is infiltrated into the porous structure of the reinforcing material under a substantial pressure. Then the combination of the reinforcing material and the matrix metal infiltrated thereinto is cooled down to a temperature below the melting point of the matrix metal, while maintaining the abovementioned substantial pressure. Optionally, the reinforcing material may be charged into a case; and, again optionally, the case may have one opening only, and a vacant space may be left between another part of the case and the reinforcing material charged in the case, with the reinforcing material interrupting communication between the opening and the vacant space. The case can be made of stainless steel, or of a refractory material such as porous brick. Possible materials for the reinforcing material include fibers of alumina, carbon, boron, or stainless steel; and possible materials for the matrix metal include aluminum and magnesium.

Method for production of composite material using preheating of reinforcing material

PURPOSE: To prevent fluctuation of the clearance between a piston and cylinder bore while to reduce the weight of piston by forming a complex reinforcing layer composed of inorganic long fiber layer and inorganic short fiber layer surrounding the former layer on the piston boss section. CONSTITUTION: A complex reinforcing layer composed of alumina-silica short fiber 2 and carbon long fiber 1 is provided in circular at the skirt shoulder section 13 in piston 10 made of Al alloy. Here, one or several kind of graphite, alumina, silicon carbide, glass as well as carbon are selected as the inorganic long fiber. While one or plural kind of alumina, silicon carbide wisker, silicon nitride wisker as well as alumina silica are selected as the inorganic short fiber. Linear thermal expansion factor in axial direction of the inorganic long fiber is set lower than 12×10 -6 /°C. Consequently, fluctuation of clearance between the piston 10 and cylinder bore is prevented while the weight of piston can be reduced. COPYRIGHT: (C)1986,JPO&Japio

Tanaka Atsuo

Papers

Fiber reinforced metal type composite material with high purity aluminum alloy containing magnesium as matrix metal

Method of producing metal base composite material under promotion of matrix metal infiltration by fine pieces of third material

Aluminum alloy composite material with intermetallic compound finely dispersed in matrix among reinforcing elements

Method for production of composite material using preheating of reinforcing material

Piston for internal combustion engine