The present disclosure relates to the field of ceramics, and discloses a metal-based aluminum nitride composite material. The composite material includes an aluminum nitride ceramic skeleton and a metal filling at least part of pores of the aluminum nitride ceramic skeleton. The aluminum nitride ceramic skeleton contains aluminum nitride and CuAlO.sub.2, and the aluminum nitride ceramic skeleton has a porosity of 20 to 40 percent. The present disclosure further discloses a method for preparing the metal-based aluminum nitride composite material and the metal-based aluminum nitride composite material obtained by the method. A CuAlO.sub.2 substance is formed in the aluminum nitride ceramic skeleton obtained in the present disclosure.

A method is presented for producing hollow microspheres of metal oxides (HMOMS) and/or hollow metal silicates microspheres (HMSMS) in a transforming solution. The transforming solution contains an atom M, or an M-ion, or a radical containing M. M in the transforming solution has the thermodynamic ability to replace silicon atoms in hollow silica microspheres (HSMS) and/or hollow glass microspheres (HGMS). The maximum temperature for transformation is set by the chemical physical properties of the transforming solution, and the viscosity of the silica in the walls of the HSMS and/or the glass in the walls of the HGMS. Viscosity, of enough magnitude, helps retain the desired shape of the hollow sphere as it is transformed to HMOMS and/or HMSMS. Non-spherical shapes can be produced by increasing the transformation temperature whereby the viscosity of the walls of the HSMS and/or the HGMS is reduced. Transformation can take place at a single temperature or at several temperatures, each temperature for a separate hold time. Methods are presented for: 1. production of micro composite castings and continuous production of sheets of micro composites, both consisting of hollow spheres in a matrix, 2. harvesting of HMOMS and HMSMS, and 3. specialty castings for anisotropic properties using 3-dimensional printing.

A method including: submerging a ceramic preform (10) in a layer (12) of powdered superalloy material (14), wherein the preform defines a desired shape of a channel (60, 62, 64, 78) to be formed in a layer (42) of superalloy material; melting the powdered superalloy material around the preform without melting the preform; and cooling and re-solidifying the superalloy material around the preform to form the layer of superalloy material with the preform defining the shape of the channel therein.

A method including: submerging a ceramic preform (10) in a layer (12) of powdered superalloy material (14), wherein the preform defines a desired shape of a channel (60, 62, 64, 78) to be formed in a layer (42) of superalloy material; melting the powdered superalloy material around the preform without melting the preform; and cooling and re-solidifying the superalloy material around the preform to form the layer of superalloy material with the preform defining the shape of the channel therein.

A molded article having a small difference in thermal conductivities between a central section and a section located at an outer peripheral surface side; and a method for producing the same; wherein, a plate-shaped molded article includes an aluminum-silicon carbide composited section in which a metal including aluminum was impregnated into a silicon carbide porous body, wherein a difference in the densities, by Archimedes' principle, of a central section of the aluminum-silicon carbide composited section and of at least a portion of an outer side section located further toward the outside peripheral surface side than the central section is 3% or less.

[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 m or more and 800 m or less, 20-30 mass % of silicon carbide having a particle diameter of 8 m or more and less than 80 m, and 5-10 mass % of silicon carbide having a particle diameter of less than 8

A silicon carbide composite that is lightweight and has high thermal conductivity as well as a low thermal expansion coefficient close to that of a ceramic substrate, particularly a silicon carbide composite material suitable for heat dissipating components that are required to be particularly free of warping, such as heat sinks. A method for manufacturing a silicon carbide composite obtained by impregnating a porous silicon carbide molded body with a metal having aluminum as a main component, wherein the method for manufacturing a silicon carbide composite material is characterized in that the porous silicon carbide molded article is formed by a wet molding method, and preferably the wet molding method is a wet press method or is a wet casting method.

A silicon carbide composite that is lightweight and has high thermal conductivity as well as a low thermal expansion coefficient close to that of a ceramic substrate, particularly a silicon carbide composite material suitable for heat dissipating components that are required to be particularly free of warping, such as heat sinks. A method for manufacturing a silicon carbide composite obtained by impregnating a porous silicon carbide molded body with a metal having aluminum as a main component, wherein the method for manufacturing a silicon carbide composite material is characterized in that the porous silicon carbide molded article is formed by a wet molding method, and preferably the wet molding method is a wet press method or is a wet casting method.

A metal matrix composite to high tolerate wear as a property has been produced by infiltration casting of a Fe Alloy and a spinel ceramic by using a material design for i) metal transport phenomena conditions, ii) predefined wetting and capillarity and iii) processing child insert/mother casting methodology to produce a final casting in shape and form to meet the needs of a mining end user.

One aspect relates to a process for producing a sintered workpiece, which includes sintering of a ceramic material at a temperature of at least 1000 C. and in an atmosphere, in the case of which the partial pressure of atmospheric air is reduced to less than 10.sup.6-times, based on the ambient air at the same temperature under equilibrium conditions.