MANUFACTURING METHOD OF ALUMINUM-DIAMOND COMPOSITE

• US 20110198771A1
• Filed: 07/14/2009
• Published: 08/18/2011
• Est. Priority Date: 07/17/2008
• Status: Active Grant

• Current Assignee: Denki Kagaku Kogyo Kabushiki Kaisha (TDK Corporation)
• Original Assignee: Denki Kagaku Kogyo Kabushiki Kaisha (TDK Corporation)
• Inventors: Tsukamoto, Hideo, Hirotsuru, Hideki
• Granted Patent: US 8,322,398 B2
• Time in Patent Office: Days
• US Class Current: 264/45.3
• CPC Class Codes: B22D 19/00 Casting in, on, or around objects which form part of the product B22D23/04 takes precedence; alumino-thermic welding B23K23/00; coating by casting molten material on the substrate C23C6/00
• CPC Class Codes: B22D 19/14 the objects being filamentary or particulate in form making alloys containing fibres or filaments by contacting the fibres or filaments with molten metal C22C47/08
• CPC Class Codes: B22F 2998/10 Processes characterised by the sequence of their steps
• CPC Class Codes: B22F 2999/00 Aspects linked to processes or compositions used in powder metallurgy
• CPC Class Codes: B22F 3/1003 Use of special medium during sintering, e.g. sintering aid
• CPC Class Codes: B22F 3/11 Making porous workpieces or articles
• CPC Class Codes: B22F 3/26 Impregnating making ferrous alloys by impregnation C22C33/0242
• CPC Class Codes: B22F 7/04 with one or more layers not made from powder, e.g. made from solid metal
• CPC Class Codes: C04B 2111/00844 for electronic applications
• CPC Class Codes: C04B 2235/3418 Silicon oxide, silicic acids, or oxide forming salts thereof, e.g. silica sol, fused silica, silica fume, cristobalite, quartz or flint glass constituents C04B2235/36
• CPC Class Codes: C04B 2235/427 Diamond
• CPC Class Codes: C04B 2235/5427 millimeter or submillimeter sized, i.e. larger than 0,1 mm
• CPC Class Codes: C04B 2235/5436 micrometer sized, i.e. from 1 to 100 micron
• CPC Class Codes: C04B 2235/5472 Bimodal, multi-modal or multi-fraction
• CPC Class Codes: C04B 2235/6027 Slip casting
• CPC Class Codes: C04B 2235/658 Atmosphere during thermal treatment
• CPC Class Codes: C04B 35/52 based on carbon, e.g. graphite
• CPC Class Codes: C04B 35/62227 obtaining fibres
• CPC Class Codes: C04B 35/6263 characterised by their solids loadings, i.e. the percentage of solids
• CPC Class Codes: C04B 38/00 Porous mortars, concrete, artificial stone or ceramic ware; Preparation thereof treating slag with gases or gas generating material C04B5/06 ; expanded graphite C04B35/536
• CPC Class Codes: C04B 41/009 : characterised by the material treated
• CPC Class Codes: C04B 41/4523 : applied from the molten state vitreous materials C04B41/5022; Thermal spraying, e.g. plasma spraying
• CPC Class Codes: C04B 41/5096 : Silicon C04B35/573 takes precedence
• CPC Class Codes: C04B 41/5155 : Aluminium
• CPC Class Codes: C04B 41/88 : Metals
• CPC Class Codes: C22C 21/00 : Alloys based on aluminium
• CPC Class Codes: C22C 26/00 : Alloys containing diamond or cubic or wurtzitic boron nitride, fullerenes or carbon nanotubes
• CPC Class Codes: H01L 21/4871 : Bases, plates or heatsinks
• CPC Class Codes: H01L 23/3732 : Diamonds
• CPC Class Codes: H01L 23/3736 : Metallic materials H01L23/3732, H01L23/3733, H01L23/3735, H01L23/3737, H01L23/3738 take precedence
• CPC Class Codes: H01L 2924/00 : Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 : Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00

Abstract

A process for the production of an aluminum-diamond composite, characterized by comprising the step of preparing a diamond powder having a specific diameter, the step of adding a colloidal silica to the diamond powder to form a slurry, the step of subjecting the slurry to press forming or slip casting to produce a compact of the diamond particles, the step of firing the compact either in air or in a nitrogen atmosphere to form a porous diamond preform, the step of heating the porous diamond preform, the step of heating an aluminum alloy to a temperature equal to or above the melting point of the alloy and impregnating the molten alloy into the porous diamond preform to make a flat plate-like aluminum-diamond composite wherein both surfaces are covered with surface layers containing an aluminum-base metal, and the step of working the aluminum-diamond composite into an aluminum-diamond composite.

Claims

1. A process for producing an aluminum-diamond composite, comprising:

a step of preparing a diamond powder composed of diamond grains having a grain size of at least 50 μ

m at 50% or more by volume of all diamond grains and diamond grains having a grain size of at most 15 μ

m at 10 to 40% by volume of all diamond grains;

a step of adding to said diamond powder a colloidal silica at 0.5 to 3% by mass in terms of solid content with respect to all diamond grains to obtain a slurry;

a step of press forming or slip casting said slurry to produce a compact of said diamond grains;

a step of firing said compact at 800°

C. to 1100°

C. in air or in a nitrogen atmosphere to obtain a porous diamond preform wherein the content of the diamond grains is 40 to 70% by volume of the total volume;

a step of heating said porous diamond preform;

a step of heating an aluminum alloy to a temperature equal to or above the melting point of the alloy and impregnating said porous diamond preform with the alloy to produce a plate-shaped aluminum-diamond composite wherein both surfaces are covered by a surface layer comprising a metal mainly composed of aluminum; and

a step of working said aluminum-diamond composite into an aluminum-diamond composite.

3. A process for producing an aluminum-diamond composite according to claim 1 or 2, characterized in that in the step of heating said porous diamond preform, a piece of ceramic paper with a thickness of 0.05 to 0.5 mm is provided on both surfaces of said porous diamond preform and said porous diamond preform is further sandwiched by said mold release plates.

4. A process for producing an aluminum-diamond composite according to any one of claims 1 to 3, further comprising a step of working said porous diamond preform before the step of heating said porous diamond preform.

2. A process for producing an aluminum-diamond composite, characterized in that:

in the step of heating said porous diamond preform, said porous diamond preform is placed in an iron or graphite frame, with said porous diamond preform being sandwiched from both surfaces by mold release plates coated with a mold release agent, and heated at 600 to 750°

C.;

in the step of producing a plate-shaped aluminum-diamond composite, an aluminum alloy comprising silicon at 0 to 25% by mass and magnesium at 0.5 to 3% by mass is heated to a temperature equal to or above the melting point of the alloy and said porous diamond preform is impregnated with the alloy at a pressure of at least 20 MPa to produce a plate-shaped aluminum-diamond composite wherein both surfaces are covered by a surface layer comprising a metal mainly composed of aluminum; and

in the step of working said aluminum-diamond composite, said aluminum-diamond composite is worked into an aluminum-diamond composite by water jet cutting or electrical discharge cutting.

5. A process for producing an aluminum-diamond composite according to any one of claims 2 to 4, wherein a side surface portion and a hole portion are formed during the step of said water jet cutting or electrical discharge cutting.