摘要:
A fibrous substrate having a first coefficient of thermal expansion and having porous characteristics is formed from discrete elements, such as carbon fibers, having anisotropic properties. A matrix formed from a refractory material encases the discrete elements and has a second coefficient of thermal expansion different from the first coefficient. The matrix has minimal chemical or mechanical bonding to the discrete elements to provide for a displacement of the matrix relative to the substrate with mechanical shock or changes in temperature. The matrix includes a first element having refractory properties and selected from the group consisting of hafnium, zirconium, tantalum, tungsten and molybdenum and also includes a second element bound to the first element. The matrix is preferably formed by providing a mixture of a first gas containing the refractory element and a second gas containing the second element and by introducing the gases into a chamber containing the substrate. The gases are introduced into the chamber at an elevated temperature and with a pressure pulsating at a particular rate between first and second pressure limits to obtain the deposition of the refractory material on the discrete elements. The gases are periodically exhausted from the chamber and fresh gases are introduced into the chamber. The matrix may consist of first and second layers respectively having hafnium (e.g. hafnium carbide) and zirconium (e.g. zirconium carbide) as the refractory materials. These layers define pores with the substrate and further define an external surface. A layer of rhenium may cover the matrix in the pores and in the external surface.
摘要:
A fiber comprises a bulk material comprising one or more materials selected from the group consisting of carbon, silicon, boron, silicon carbide, and boron nitride; and a metal whose affinity for oxygen is greater than the affinity for oxygen of any of the one or more materials. The metal may be selected from the group consisting of beryllium, titanium, hafnium and zirconium. At least a first portion of the metal may be present in un-oxidized form at the entrance to and/or within grain boundaries within the fiber.A method of improving at least one of the strength, creep resistance, and toughness of a fiber comprises adding to a fiber, initially comprising a bulk material having a first affinity for oxygen, a metal that has a second affinity for oxygen higher than the first affinity. The metal may be selected from the group consisting of beryllium, titanium, hafnium and zirconium.
摘要:
[Problem to be Solved]Provided are an aluminum-silicon-carbide composite having high thermal conductivity, low thermal expansion, and low specific gravity and a method for producing the composite.[Solution]Provided is an aluminum-silicon-carbide composite formed by impregnating a porous silicon carbide molded body with an aluminum alloy. The ratio of silicon carbide in the composite is 60 vol % or more, and the composite contains 60-75 mass % of silicon carbide having a particle diameter of 80 μm or more and 800 μm or less, 20-30 mass % of silicon carbide having a particle diameter of 8 μm or more and less than 80 μm, and 5-10 mass % of silicon carbide having a particle diameter of less than 8
摘要:
The presently disclosed technology relates to carbon-on-carbon (C/C) manufacturing techniques and the resulting C/C products. One aspect of the manufacturing techniques disclosed herein utilizes two distinct curing operations that occur at different times and/or using different temperatures. The resulting C/C products are substantially non-porous, even though the curing operation(s) substantially gasify a liquid carbon-entrained filler material that saturates a carbon fabric that makes up the C/C products.
摘要:
Brake disks with integrated heat sink are provided. Brake disk includes a fiber-reinforced composite material and an encapsulated heat sink material impregnated into the fiber-reinforced composite material. The encapsulated heat sink material comprises a heat sink material encapsulated within a silicon-containing encapsulation layer. Methods for manufacturing the brake disk with integrated heat sink and methods for producing the encapsulated heat sink material are also provided.
摘要:
A composite member has a substrate made of a composite material having SiC combined with magnesium or a magnesium alloy, and has a warpage degree of not less than 0.01×10−3 and not more than 10×10−3, the warpage degree being defined as lmax/Dmax, where lmax being a difference between a maximum value and a minimum value of surface displacement of one surface of composite member measured along a longest side thereof, and Dmax being a length of the longest side. Thereby, a composite member capable of efficiently dissipating heat to an installation object, a heat-dissipating member using the composite member, and a semiconductor device having the heat-dissipating member are provided.
摘要:
The present disclosure provides a composite heat-dissipation substrate and a method of manufacturing the same. The composite heat-dissipation substrate includes a first ceramic layer having insulating properties, a second porous ceramic layer and a metal layer, wherein the first ceramic layer and the second ceramic layer are continuously connected to each other so as not to form an interface therebetween, and the metal layer is infiltrated into plural pores of the second ceramic layer to be coupled to the ceramic layers, whereby interfacial coupling force between the ceramic layers and the metal layer is very high, thereby providing significantly improved heat dissipation characteristics.
摘要:
An insulation sheet made from silicon nitride comprising: a sheet-shaped silicon-nitride substrate which contains β-silicon-nitride crystal grains as a main phase; and a surface layer which is formed on one face or both front and back faces of surfaces of the silicon-nitride substrate and is formed from a resin or a metal which includes at least one element selected from among In, Sn, Al, Ag, Au, Cu, Ni, Pb, Pd, Sr, Ce, Fe, Nb, Ta, V and Ti. A semiconductor module structure using the insulation sheet made from silicon nitride.
摘要:
An insulation sheet made from silicon nitride comprising: a sheet-shaped silicon-nitride substrate which contains β-silicon-nitride crystal grains as a main phase; and a surface layer which is formed on one face or both front and back faces of surfaces of the silicon-nitride substrate and is formed from a resin or a metal which includes at least one element selected from among In, Sn, Al, Ag, Au, Cu, Ni, Pb, Pd, Sr, Ce, Fe, Nb, Ta, V and Ti. A semiconductor module structure using the insulation sheet made from silicon nitride.
摘要:
A composite article including a body made of recrystallized silicon carbide and an infiltrant, wherein the body comprises a static impact resistance of at least about 1800 MPa.