U.S. patent application number 17/258944 was filed with the patent office on 2021-11-04 for process for producing a material composite, material composite and use of the material composite as a heat conductor and heat exchanger.
This patent application is currently assigned to TECHNISCHE UNIVERSITAT BERLIN. The applicant listed for this patent is TECHNISCHE UNIVERSITAT BERLIN. Invention is credited to Thomas HUTSCH, Jens RIESSELMANN, Thomas WEISSGARBER.
Application Number | 20210339314 17/258944 |
Document ID | / |
Family ID | 1000005768986 |
Filed Date | 2021-11-04 |
United States Patent
Application |
20210339314 |
Kind Code |
A1 |
RIESSELMANN; Jens ; et
al. |
November 4, 2021 |
PROCESS FOR PRODUCING A MATERIAL COMPOSITE, MATERIAL COMPOSITE AND
USE OF THE MATERIAL COMPOSITE AS A HEAT CONDUCTOR AND HEAT
EXCHANGER
Abstract
Processes produce a compound material structure by producing a
composite material which extends along an axis of elongation from
carbon nanostructures anchored in a matrix of a first metal
extending along the axis of elongation of the composite material.
The processes comprise dividing the composite material into
segments of the composite material, arranging the segments in a
plane of a die matrix, filling free spaces in the die matrix with a
filler material and subsequently sintering in the die matrix to
form a compound material structure or squeeze casting in the die
matrix, and exposing the carbon nanostructures of the composite
material on at least one surface of the compound material structure
such that the carbon nanostructures protrude out of this surface.
Compound material structures and uses thereof as a heat conductor
and/or a heat exchanger are also provided.
Inventors: |
RIESSELMANN; Jens; (Berlin,
DE) ; HUTSCH; Thomas; (Dresden, DE) ;
WEISSGARBER; Thomas; (Dresden, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
TECHNISCHE UNIVERSITAT BERLIN |
Berlin |
|
DE |
|
|
Assignee: |
TECHNISCHE UNIVERSITAT
BERLIN
Berlin
DE
|
Family ID: |
1000005768986 |
Appl. No.: |
17/258944 |
Filed: |
July 1, 2019 |
PCT Filed: |
July 1, 2019 |
PCT NO: |
PCT/EP2019/067593 |
371 Date: |
January 8, 2021 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F28F 2255/18 20130101;
B22F 2301/10 20130101; F28F 2255/20 20130101; B22F 3/10 20130101;
F28F 21/02 20130101; B22F 2302/406 20130101; F28F 2013/001
20130101; B22F 3/24 20130101; B22F 3/20 20130101; B22F 2003/247
20130101 |
International
Class: |
B22F 3/20 20060101
B22F003/20; F28F 21/02 20060101 F28F021/02; B22F 3/10 20060101
B22F003/10; B22F 3/24 20060101 B22F003/24 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 9, 2018 |
DE |
10 2018 116 559.5 |
Claims
1. A process for producing a compound material structure the
process comprising: producing a composite material extending along
an axis of elongation (z) from carbon nanostructures anchored in a
matrix of a first metal; dividing the composite material into
segments; arranging the segments in at least one plane in a die
matrix; forming a compound material structure by filling free
spaces in the die matrix with a filler material and subsequent
sintering in the die matrix, or squeeze casting in the die matrix;
exposing the carbon nanostructures out of at least one surface of
the compound material structure such that the carbon nanostructures
protrude out of the at least one surface of the compound material
structure.
2. The process according to claim 1, wherein the carbon
nanostructures are round, layered, or fibrous carbon
nanoparticles.
3. The process according to claim 1, wherein the composite material
is a rod-shaped composite material and the cross-sectional surface
of the rod-shaped composite material has a basic geometrical shape
comprising, a circular basic geometrical shape, a trapezoidal basic
geometrical shape, a rectangular basic geometrical shape, or a
square basic geometrical shape or subsections of the basic
geometrical shape.
4. The process according to claim 1, further comprising shaping by
machining; and grinding the at least one surface from which the
carbon nanostructures are to be exposed, wherein both the shaping
and grinding are carried out after the die matrix has been
sintered.
5. The process according to claim 1, wherein the producing of the
composite material is carried out by powder metallurgy and
comprises: producing a homogeneous powder mixture from the first
metal and the carbon nanostructures; and sintering the homogeneous
powder mixture to form a composite material; and/or extruding the
composite material.
6. The process according to claim 1, wherein the carbon
nanostructures are exposed over a length of 5-50 .mu.m on the at
least one surface of the compound material structure.
7. The process according to claim 1, wherein the first metal is
copper.
8. The process according to claim 1, wherein the filler material
has a higher thermal conductivity than the composite material.
9. The process according to, wherein the filler material: comprises
a second metal; is copper; is a copper-diamond composite material;
or is a copper-graphite composite material.
10. The process according to claim 1, wherein at least one first
layer of at least one other material is introduced into the die
matrix in the plane of the composite material.
11. The process according to claim 1, wherein, prior to the
introduction of the segments into the die matrix, the die matrix
was filled with at least one second layer of at least one other
material and the segments are disposed thereon.
12. The process according to claim 11, wherein the at least one
first and at least one second layers have a lower or higher thermal
conductivity compared with the composite material such that one or
more heat conduction pathways are formed.
13. A compound material structure obtained by the process according
to claim 1.
14. A method comprising: conducting or exchanging heat between two
surfaces via a reusable and effective interface comprising the
compound material structure according to claim 13.
15. The process according to claim 6, wherein the carbon
nanostructures are exposed over a length of 10-30 .mu.m on the at
least one surface of the compound material structure.
Description
[0001] Process for the production of a compound material structure,
a compound material structure as well as use of the compound
material structure as a heat conductor as well as a heat
exchanger
[0002] The invention relates to a process for the production of a
compound material structure, a compound material structure, as well
as to the use of the compound material structure as a heat
conductor as well as a heat exchanger.
[0003] Wherever heat is generated in electronic components as a
result of power loss, it also has to be dissipated in order to
prevent the components from overheating. There are many
applications in the prior art which benefit from increasing the
flow of heat between two surfaces. In spacecraft in particular, in
which no convection can take place because of the environmental
conditions, wired heat transport between two surfaces in particular
is decisive. The temperature in the components can be controlled
better by means of enhanced thermal connection of the components to
the remaining satellite bus and in particular to radiators. When
surfaces are connected together, there is a flow of heat between
them which is a function, inter alia, of the contact surface area,
the roughness, the contact pressure and the material properties.
The effective contact surface area is significantly reduced here
because on a microscopic level, the surfaces are not flat. This is
illustrated in FIGS. 1 and 2 with the aid of two different contact
layers 1 and 2. Polishing or lapping the surface is possible in
order to increase this surface area, but this still leaves a
residual microscopic roughness.
[0004] However, the flow of heat between the surfaces does not only
occur via the contact surfaces, but also via the gaps between the
surfaces by radiation or thermal conduction or convection of the
medium which is between them. However, in a vacuum, there is in
fact no convective heat conduction.
[0005] In order to increase the heat conduction between two
surfaces, to the present date, various "Thermal Interface
Materials" (TIMs) have been developed with which the gaps are
filled.
[0006] In this regard, it is standard for heat conducting gels,
pastes or other materials which are partially based on carbon to be
used here which, however, cannot as a rule be recycled but have to
be changed when a fresh contact is made.
[0007] Carbon nanostructure arrays lend themselves for use as
Thermal Interface Materials because the carbon nanostructures,
preferably carbon nanotubes (CNT), have a thermal conductivity in
their direction of growth of up to 3500 W/m K. Such an option for
an interface based on carbon nanotubes as "Thermal Interface
Materials" is proposed in US patent U.S. Pat. No. 7,416,019. In it,
the carbon nanotubes are fastened to the surface or are grown on
the surface of a metal.
[0008] The aim of the invention is to provide a reusable and
effective interface for conducting or exchanging heat between two
surfaces.
[0009] The process for the production of a compound material
structure in accordance with the invention generally comprises the
following steps: production of a composite material which extends
along an axis of elongation, produced from carbon nanostructures
anchored in a matrix of a first metal; dividing the composite
material into segments, in particular by sawing, for example along
or perpendicular to the axis of elongation of the composite
material; arranging the segments in a plane of a die matrix;
filling free spaces in the die matrix with a filler material,
sintering in the die matrix to form a compound material structure,
exposing the carbon nanostructures of the composite material from
at least one surface of the compound material structure, so that
the carbon nanostructures protrude out of this surface and still in
part remain anchored in the base material.
[0010] This process has the advantage that on the one hand, as a
result of the protruding carbon nanostructures, the contact surface
area between two surfaces is increased, and on the other hand,
because the carbon nanostructures are embedded in the metal matrix
in a stable manner, an interface produced from a compound material
structure of this type can be configured so as to be
releasable.
[0011] The term "carbon nanostructures" as used below should be
understood to mean structures such as round carbon nanoparticles
such as fullerenes and amorphous carbons, for example, or layered
carbon nanoparticles such as graphites and nanoplatelets, for
example, or fibrous carbon nanoparticles such as carbon nanotubes
and carbon nanofibers, for example. Preferably, the carbon
nanostructures are carbon nanotubes.
[0012] In this manner, the invention allows the interface surface
area to be increased and/or the contact surface area of a
releasable and reusable thermal interface to be increased,
whereupon the flow of heat between two surfaces is increased.
[0013] The carbon nanostructures may extend in the metal in a
randomly distributed manner. In a preferred exemplary embodiment,
the carbon nanostructures extend along the axis of elongation of
the composite material. After exposing the carbon nanostructures,
they then protrude out of the surface of the composite material,
preferably in one direction. This provides improved contact,
improved heat transfer and improved reusability of the
interface.
[0014] In particular the composite material may be a rod-shaped
composite material and the cross-sectional surface of the
rod-shaped composite material may have any basic geometrical shape,
in particular a circular, trapezoidal, rectangular or square basic
shape, or it may be formed from circular segments.
[0015] Preferably, the process comprises the following steps which
follow sintering in the die matrix: shaping the sintered body by
forming, for example by extrusion, ECAP (Equal Channel Angular
Pressing) or rotary swaging, machining, and grinding the surface of
the composite material from which the carbon nanostructures are to
be exposed.
[0016] The production of the composite material is preferably
carried out by powder metallurgy and comprises the following steps:
production of a homogeneous powder mixture from a first metal and
from carbon nanostructures, sintering the powder mixture to form a
composite material, and extrusion of the composite material. Direct
extrusion of the homogeneous powder mixture is also possible.
[0017] The carbon nanostructures are preferably exposed to a length
of 5-30 .mu.m, more preferably 10-20 .mu.m.
[0018] The first metal is preferably copper. However, any other
metal may also be used.
[0019] Thus, the invention proposes an increase in the interface
surface and/or contact surface area of a releasable and reusable
thermal interface for increasing the flow of heat between two
surfaces produced from metal-carbon composite materials, in
particular from copper--carbon nanostructures, by the formation of
a compound material structure, in particular via copper or
copper--carbon composite materials for different atmospheres,
preferably in vacuum in a pressure zone of less than 1*10.sup.-2
mbar.
[0020] The filler material preferably has a higher thermal
conductivity than the composite material. In this manner, the
overall thermal conductivity can be improved. The filler material
can be introduced using powder metallurgy and/or smelting
metallurgy methods.
[0021] In particular, the filler material comprises a second metal.
This may be copper. The filler material may be a metal-carbon
composite material. Metal-diamond composite materials are possible,
preferably copper-diamond, or a metal-graphite composite material,
preferably copper-graphite. These materials are particularly
suitable for improving the thermal conductivity.
[0022] In one exemplary embodiment, at least one first layer of at
least one other material may be introduced into the die matrix in
the plane of the composite material. As an alternative, or in
addition, prior to the step of introducing the segments into the
die matrix, the die matrix may already have been filled with at
least one second layer of at least one other material and the
segments can be disposed thereon. The first and second layers
preferably have a higher thermal conductivity than the composite
material.
[0023] In this manner, an interface produced from the compound
material structure can be specifically adapted to the dimensions of
components and the thermal conductivity requirements.
[0024] Furthermore, the invention encompasses a compound material
structure which has been produced in accordance with the invention
as described above.
[0025] Furthermore, a use of a compound material structure in
accordance with the invention as a thermal conduction material and
heat exchange material is proposed.
[0026] The properties, features and advantages of this invention as
well as the ways of generating them will become clearer and more
comprehensible from the more detailed description made in
association with the following description of exemplary embodiments
which are explained in more detail in association with the
drawings, in which:
[0027] FIG. 1 diagrammatically shows a non-contacted thermal
interface of the prior art and consists of two contact layers,
[0028] FIG. 2 diagrammatically shows a contacted thermal interface
of the prior art of FIG. 1,
[0029] FIG. 3 shows the composite material in accordance with the
invention after extrusion, with exposed carbon nanostructures,
[0030] FIG. 4 diagrammatically shows a non-contacted thermal
interface with a composite material in accordance with the
invention, in a first exemplary embodiment,
[0031] FIG. 5 diagrammatically shows a contacted thermal Interface
from FIG. 4,
[0032] FIG. 6 diagrammatically shows a second exemplary embodiment
of a non-contacted thermal interface in accordance with the
invention,
[0033] FIG. 7 diagrammatically shows a further possible arrangement
of a thermal interface in accordance with the invention,
[0034] FIG. 8 shows, by way of example, a possible rod of composite
material after extrusion,
[0035] FIG. 9 shows a cropped segment of the extruded composite
material,
[0036] FIG. 10 shows, by way of example, the arrangement of several
segments in the die matrix, in preparation for sintering,
[0037] FIG. 11 shows a compound material structure in accordance
with the invention, mechanically and thermally composited by
sintering,
[0038] FIG. 12 shows an exemplary/diagrammatic representation of a
machined, ground and etched compound material structure in
accordance with the invention,
[0039] FIG. 13 shows a representation of a compound material
structure which has been produced and ground,
[0040] FIG. 14 shows a representation of a produced, ground and
etched compound material structure for verification of the
process,
[0041] FIG. 15 diagrammatically shows an embodiment in accordance
with the invention of a thermal interface connected to a body with
a material with a lower, identical or higher thermal
conductivity,
[0042] FIG. 16 diagrammatically shows an embodiment in accordance
with the invention of a thermal interface connected to a body with
a material with a lower thermal conductivity and an identical or
higher thermal conductivity at several sites for the formation of
specific heat conduction pathways,
[0043] FIG. 17 diagrammatically shows the process in accordance
with the invention for the production of a compound material
structure.
[0044] FIG. 1 shows a non-contacted thermal interface of the prior
art. Here, the thermal interface consists, for example and in a
non-limiting manner, of a respective metallic contact layer 1 and 2
which each have microscopically roughened surfaces which face each
other. If these two surfaces are brought together into contact, as
can be seen in FIG. 2, this results in an effective surface area
for contact-associated heat exchange from the sum of the points of
contact 3 between the contact layers 1 and 2. The heat can only be
transferred via the gaps 4 between the points of contact 3 by
radiation or convection of the enclosed medium. However, in a
vacuum, convection cannot occur.
[0045] Thus, in accordance with the invention, a compound material
structure produced from metal-carbon composite materials is
proposed, in particular produced from copper and carbon
nanostructures such as, for example, carbon nanotubes, but not
limited thereto. In the composite material, the carbon
nanostructures are anchored in a metal matrix. In this manner, they
protrude out of a surface and thus can be used for a thermal
interface, as "Thermal Interface Materials" (TIM).
[0046] In this regard, the metal-carbon composite material is
produced by powder metallurgy. A first metal acts as the matrix and
the carbon is primarily acting as a reinforcing component.
Advantageously, there is a variety of possibilities for subsequent
shaping of the composite material. As an example, but not limited
thereto, after the production of a homogeneous powder mixture, the
metal-carbon nanostructure composite material can be provided with
a shape, in particular by extrusion. In this regard, the carbon
nanostructures, preferably carbon nanotubes, are orientated
substantially parallel to the extrusion direction in one dimension.
After extrusion, the composite materials can be machined as normal.
Thus, the surface can brought to the shape that is suitable for the
thermal interface and be made smaller by processes such as lapping
to a roughness of up to 10 .mu.m, preferably up to 1 .mu.m and
below.
[0047] By etching away the uppermost metal layer on the end face,
the carbon nanostructures which were embedded therein can be
exposed, preferably over a length of up to 10 .mu.m, more
preferably up to 20-30 .mu.m. The carbon nanostructures which
therefore protrude out of the surface are still firmly anchored in
the metal matrix. A composite material 20 of this type after
extrusion is shown in FIG. 3. After extrusion, the carbon
nanostructures 22 are exposed by etching away a first metal 24 at
the surface. Because the carbon nanostructures 22 are anchored in
the first metal 24, preferably copper, the carbon nanostructures 22
are not as easy to detach from the corresponding contact layers 1
and 2 upon separation. As a result of this, the composite material
20 is better suited to releasability and reusability of the
interface. The surface of the composite material 20 has zones of
the first metal 24 through which the carbon nanostructures 22 pass
or protrude from the surface. In FIG. 3, the composite material 20
extends along an axis of elongation in the z-direction. The side
face(s) of the composite material 20 are formed from the first
metal 24. However, these sides can also be etched away.
[0048] FIG. 4 diagrammatically shows a non-contacted thermal
interface which, by way of example, has a metallic contact layer 1
on one side and a contact layer 2 consisting of a metal-carbon
nanostructure composite material 20 as described above on the other
side. The carbon nanostructures 22 of the front face of the
composite material 20 have been exposed here by etching, by way of
example. FIG. 5 now diagrammatically shows the contacted thermal
interface of FIG. 4. In this regard, the number of contact points 3
compared with the number of contact points 3 in FIG. 2 is
significantly higher because of the carbon nanostructures 22
embedded in the first metal 24.
[0049] FIG. 6 diagrammatically shows a further exemplary embodiment
of a non-contacted interface in accordance with the invention. This
now consists of two respective metal--carbon nanostructure
composite materials 20 as described above with exposed carbon
nanostructures 22. In the contacted state, the respective carbon
nanostructures 22 touch the surface produced from the first metal
24 or the carbon nanostructures 22 of the other contact layer. In
this manner, the thermal conductivity is increased still further.
FIG. 6 shows carbon nanotubes 22 purely by way of example. However,
these may also be any other carbon nanostructure 22 such as round
carbon nanoparticles, for example fullerenes and amorphous carbon
materials, or layered carbon nanoparticles, for example graphites
and nanoplatelets, or fibrous carbon nanoparticles, for example
carbon nanofibres. Preferably, however, and in a non-limiting
manner, the carbon nanostructures are carbon nanotubes.
[0050] FIG. 7 diagrammatically shows a further possible arrangement
of the thermal interface. In addition to the variations discussed
above, here, the surfaces with and without carbon nanostructures 22
on both sides of the thermal interface are respectively offset with
respect to each other. By means of the offset arrangement of the
regions with and without carbon nanostructures on the two contact
layers 1 and 2, releasability of the interface can be improved.
[0051] The contact surfaces which can be produced and a possible
shape for the thermal Interfaces are limited in the process which
produces the composite material 20. In order to expand this and
provide an adaptive design, a production process for the production
of a compound material structure is proposed which makes it
possible to connect together mechanically and thermally interface
elements which have been produced by the process described
above.
[0052] As a result of this, the contact surface areas of an
interface body can be increased and can be made into any shapes. In
this manner, in particular, interface rings produced from circular
segments can be produced.
[0053] To this end, a powder metallurgy process in accordance with
the invention will now be described.
[0054] FIG. 8 shows, by way of non-limiting example, a rod-shaped
composite material 20 with a cross-sectional surface 26 produced
from a circular segment following an extrusion step. The
cross-sectional surface 26 of the rod-shaped composite material 20
can in fact have any basic geometrical shape, in particular a
circular, trapezoidal, rectangular or square basic shape. This rod
extends along an axis of elongation z and in the example shown, is
used for the preparation of circular segments in FIG. 9. The carbon
nanostructures 22 also extend along the axis of elongation z out of
a surface of the composite material 20. Preferably, the composite
material 20 is in the shape of a rod, so that it can be partitioned
easily, for example by sawing. The rod which is produced by
extrusion is divided into segments 30 of an appropriate thickness,
but preferably not limited to sawing. These segments 30 are shown
in FIG. 9. The shape and outline of the composite material 20 is
not limited to that shown in the exemplary embodiment. The outline
may have any shape, for example square, rectangular, circular,
elliptical, etc. Production may be such that a sheath produced from
a first metal 24 is formed around the composite material 20 and
which can be machined away if required. This sheath may, however,
also be used for further joining (for example by soldering).
[0055] The segments 30 are disposed in a die matrix 100 with a
selected shape. FIG. 10 shows, by way of non-limiting example, that
a circular shape has been selected as the die matrix 100. The
segments 30 are disposed in the die matrix so that they form a
circular ring 110 and the free spaces 120 that are between them are
then filled with a filler material 130, as shown in FIG. 11. The
filler material 130 is preferably a metal powder, more preferably
copper powder. In the exemplary embodiment shown, in the interior
of the die matrix 100 there is no composite material 20 around the
centre of the circle; only the filler material 130 is disposed
there. The filler material 130 and the segments 30 are connected
together, for example by sintering, to form a common body 200.
[0056] Particularly in the case of circular rings, the inner region
may be filled with the filler material 130 in order to be used as a
clamping area for later machining. After sintering, the compound
material structure can be machined to the final shape.
[0057] In one exemplary embodiment, segments of the composite
material may be disposed in a plane in a die matrix which can be
used as a squeeze casting tool. The die matrix is then pre-heated
to temperatures between 400.degree. C. and 600.degree. C.,
preferably in a vacuum. As an example, molten metal or a metal
alloy, for example copper at a temperature between 1200.degree. C.
and 1300.degree. C., for example under vacuum (<20 bar) and at a
predetermined pressure, then penetrates into the voids between the
segments. The predetermined pressure may be between 50 MPa and 100
MPa, for example approximately 80 MPa. The penetration period may
be between 35 and 50 seconds. Next, solidification is carried out
under pressure. The compound material structure can then be pushed
out of the die matrix and can cool further in air.
[0058] FIG. 12 shows a representation of a machined, ground and
etched compound material structure 200 which has been produced by
the aforementioned steps. As an example, the compound material
structure 200 is formed as a ring and has individual holes in the
ring which can be used for fastening. The last steps of the process
are grinding the surface of the compound material structure, the
result of which is shown in FIG. 13, as well as etching in order to
expose the carbon nanostructures (FIG. 14).
[0059] The interface can be used both when the carbon
nanostructures 22 are exposed on one side or in fact on both sides
of the contact surfaces. It is also possible to use it against
another solid material.
[0060] The thermal conductivity of the compound material structure
200 can therefore be adjusted in this manner. Metal-diamond or
metal-graphite composite materials have a higher thermal
conductivity than the pure metal or the metal--carbon nanostructure
composite material 20. The thermal conductivity of copper-diamond
is up to 700 W/m K and that of copper-graphite is up to 600 W/m K,
while the thermal conductivity of pure copper is approximately 400
W/m K. Thus, they can also be used for passive cooling. This can
also be employed for this invention. In order to increase the
thermal conductivity, in particular, the filler material 130 for
connecting the compound material structure can be substituted by a
metal-diamond composite material. Metal-diamond composite materials
are distinguished by a higher thermal conductivity in all
directions in space compared with pure metal, whereupon the entire
amount of heat to be exchanged can be increased still further.
[0061] In this manner, the compound material structure 200 can be
shaped and adapted in many ways. FIG. 15 diagrammatically shows a
compound material structure 200 with a first subsection 210
produced from the composite material 20, connected to a body with a
second subsection 220 which is formed from a material with a lower,
identical or higher thermal conductivity. The connection may also
be produced by sintering or squeeze casting. The material of the
second section 220 may be disposed in the die matrix 100 together
with the segments 30 of the composite material 20. By selecting a
material with a higher or lower thermal conductivity for the second
subsection 220, specific heat conduction pathways can be formed.
The rigidity and strength can also be raised in this manner.
[0062] A more complicated exemplary embodiment of a compound
material structure 200 is shown in FIG. 16. Here, the compound
material structure 200 consists of two plies of different
materials. Thus, for example, a third section 230 may be disposed
below the composite material 20 and have a lower thermal
conductivity than the composite material 20 of the first section
210. The fourth section 240 may have an identical or, preferably,
higher thermal conductivity, whereupon the heat is conducted away
laterally.
[0063] FIG. 17 shows a process in accordance with the invention for
the production of a compound material structure. In step S100,
initially, a composite material 20 is produced from carbon
nanostructures 22 anchored in a matrix of a first metal 24. Here,
the composite material 20 extends along an axis of elongation z.
The carbon nanostructures 22 also extend along the axis of
elongation z of the composite material 20. In step S200, the
composite material 20 is divided into segments 30, preferably cut
segments 30. In this manner, the segments 30 are disposed in at
least one plane in a die matrix 100, at S300. In step S400, a
compound material structure 200 is then formed. This may be carried
out by filling, at S410, the free spaces 120 in the die matrix with
a filler material 130 and subsequent sintering, at S420, in the die
matrix 100. As an alternative, this may also be carried out by
squeeze casting, at S430, in the die matrix 100. Next, in step
S500, the carbon nanostructures 22 on at least one surface of the
compound material structure 200 are exposed, so that the carbon
nanostructures 22 protrude out of this surface.
[0064] In summary, carbon nanostructures anchored in a metallic
matrix are proposed as Thermal Interface Materials (TIM) and heat
exchange materials. These can advantageously be used in a
releasable and reusable thermal interface. In accordance with the
invention, a compound material structure can be produced by
sintering, for local integration of the thermal active interface
surface into a metal, a metal alloy and/or a composite material
(metal/diamond, metal/graphite).
[0065] In addition, specific thermally active interface surfaces
made from metal/carbon nanostructure composite materials for heat
exchange and a material with a lower thermal conductivity (ceramic,
metal, metal alloys and composite materials) as the composite
material for the formation of specific conducting pathways (thermal
partitioning) can be constructed.
[0066] Advantageously, the thermally active interface surface can
be regenerated by spe fic etching and can be adjusted to the
contours.
[0067] Although the invention has been illustrated and described in
detail with the aid of preferred exemplary embodiments, the
invention is not limited to the examples disclosed and other
variations can be envisaged by the person skilled in the art
without departing from the scope of the invention.
LIST OF REFERENCE NUMERALS
[0068] 1 first contact layer [0069] 2 second contact layer [0070] 3
contact points [0071] 4 gaps between contact points [0072] 20
composite material [0073] 22 carbon nanostructures [0074] 24 first
metal [0075] 26 cross-sectional surface [0076] 30 segments [0077]
100 die matrix [0078] 110 die matrix segment [0079] 120 free space
[0080] 130 filler material [0081] 200 compound material structure
[0082] 210 first section [0083] 220 second section [0084] 230 third
section [0085] 240 fourth section
* * * * *