摘要:
Channel boxes for a boiling water reactor and methods of manufacture thereof are provided. The channel box comprises a substrate and a first layer. The substrate comprises a tubular shape. The substrate comprises silicon carbide fibers. The first layer is deposited on a first surface of the substrate and the first layer comprises a corrosion resistant metallic composition.
摘要:
A net shaped ceramic-reinforced aluminum matrix composite is produced by forming a permeable mass of ceramic material with a defined surface boundary having a barrier, and contacting a molten aluminum-magnesium alloy with the permeable mass of ceramic material in the presence of a gas comprising from about 10 to 100% nitrogen, by volume, balance nonoxidizing gas, e.g. hydrogen or argon. Under these conditions, the molten alloy spontaneously infiltrates the ceramic mass under normal atmospheric pressures until it reaches the barrier. A solid body of the alloy can be placed adjacent to a permeable bedding of ceramic material having a barrier, and brought to the molten state, preferably to at least about 700.degree. C., in order to form the net shape aluminum matrix composite by spontaneous 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.
摘要:
There is provided a process for producing an intermetallic compound-based composite material containing a reinforcing material and an intermetallic compound. The process includes infiltrating a metal powder into the gaps of a reinforcing material to form a preform and impregnating the preform with an Al melt to give rise to a spontaneous combustion reaction between the metal powder and the Al melt to convert the Al melt into an aluminide intermetallic compound. The Al melt and the metal powder are used in such amounts that they do not remain after the spontaneous combustion reaction. The process can produce an intermetallic compound-based composite material of large size and complicated shape in reduced steps.
摘要:
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.degree. 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.
摘要:
This invention provides a process which permits impurity-free sound Mg-based composite materials and Mg alloy-based composite materials to be efficiently and inexpensively produced without pressurizing a melt of matrix metal and without using a metal oxide, finely divided metal or metal fluoride. Specifically, it provides a process for producing an Mg-based composite material or an Mg alloy-based composite material which comprises replacing the gas within a mass of reinforcing material (9) by a non-protective gas, and bringing at least a part of the mass of reinforcing material (9) into contact with a melt (7) of Mg or Mg alloy so as to infiltrate the melt (7) into the mass of reinforcing material (9).
摘要:
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.degree. 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.
摘要:
In this method for manufacturing an aluminum alloy, a porous preform is manufactured from a mixture of a finely divided oxide of a metallic element which has a weaker tendency to form oxide than does aluminum, and an additional substance substantially more finely divided than that metallic oxide. Then an aluminum alloy containing a substantial quantity of silicon is permeated in the molten state through the porous preform. This causes the metallic oxide to be reduced by a thermite reaction, to leave the metal which it included as alloyed with the aluminum alloy. At this time, the silicon in the aluminum alloy does not tend to crystallize out upon the particles of the metallic oxide, which would interfere with such a reduction reaction by forming crystalline silicon shells around such metallic oxide particles and would lead to a poor final product, because instead the silicon tends to crystallize out upon the particles of the additional substance. This alloying method is effective even if the average particle diameter of the finely divided metallic oxide, on the assumption that it is in the form of globular particles, is less than about 10 microns. The melting point of the additional substance should desirably be substantially higher than the melting point of the aluminum alloy. The silicon content of the aluminum alloy may freely be greater than about 1.65% by weight. Desirably, the preform may further contain reinforcing fibrous material. And, particularly, the additional substance may be Al.sub.2 O.sub.3.
摘要:
An aluminum base composite material (10) having an aluminum alloy (11) as a base material and, incorporated therein, a reinforcing material (12) composed of alumina particles of alumina fibers, wherein a spinel layer (13) is formed on the surface of the reinforcing material and an aluminum nitride layer (14) exhibiting excellent wettability is formed on the surface of said spinel layer.
摘要:
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.degree. 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.
摘要:
First a quantity of reinforcing material is formed into a shaped mass bound together by an inorganic binder. Next, this shaped mass is compounded with a quantity of a molten matrix metal by a pressure casting method. The molten matrix metal includes a quantity of a certain element with a strong tendency to become oxidized, and the inorganic binder includes a metallic oxide which, when brought into contact at high temperature with this certain element, is reduced thereby in an exothermic reaction. Thus, during the pressure casting, extra heat is produced as the certain element reduces the metallic oxide, and this aids good penetration of the matrix metal into the interstices of the reinforcing material. The metal remaining from the oxide is dispersed in the matrix metal. This metallic oxide may be silica, zirconia, chromium oxide, yttrium oxide, cerium oxide, ferric oxide, zirconium silicate, antimony oxide, or a mixture thereof; and the certain element may be lithium, calcium, magnesium, aluminum, beryllium, titanium, zirconium, or a mixture thereof.