U.S. patent application number 11/412334 was filed with the patent office on 2006-11-09 for method of manufacturing composite material.
Invention is credited to Kyoichi Kinoshita, Eiji Kono, Hidehiro Kudo, Katsufumi Tanaka.
Application Number | 20060249500 11/412334 |
Document ID | / |
Family ID | 36600235 |
Filed Date | 2006-11-09 |
United States Patent
Application |
20060249500 |
Kind Code |
A1 |
Kudo; Hidehiro ; et
al. |
November 9, 2006 |
Method of manufacturing composite material
Abstract
A method of manufacturing metal matrix composite with ceramic
particles as a disperse phase includes the steps of holding the
single metal matrix composite or the plurality of layered metal
matrix composites between a pair of pressing dies, pressing the
metal matrix composite by the pressing dies, and heating the metal
matrix composite.
Inventors: |
Kudo; Hidehiro; (Kariya-shi,
JP) ; Kinoshita; Kyoichi; (Kariya-shi, JP) ;
Tanaka; Katsufumi; (Kariya-shi, JP) ; Kono; Eiji;
(Kariya-shi, JP) |
Correspondence
Address: |
MORGAN & FINNEGAN, L.L.P.
3 World Financial Center
New York
NY
10281-2101
US
|
Family ID: |
36600235 |
Appl. No.: |
11/412334 |
Filed: |
April 26, 2006 |
Current U.S.
Class: |
219/243 |
Current CPC
Class: |
B22F 2998/10 20130101;
C22C 1/1036 20130101; B22D 19/14 20130101; C22C 1/1036 20130101;
B22F 3/14 20130101; C22C 2001/1073 20130101; C22C 1/1094 20130101;
B22F 2998/10 20130101 |
Class at
Publication: |
219/243 |
International
Class: |
C22C 1/05 20060101
C22C001/05; B22D 18/02 20060101 B22D018/02; B22D 19/14 20060101
B22D019/14; B22D 27/09 20060101 B22D027/09 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 27, 2005 |
JP |
2005-129891 |
Claims
1. A method of manufacturing metal matrix composite with ceramic
particles as a disperse phase, comprising the steps of: holding a
single metal matrix composite or a plurality of layered metal
matrix composites, each having a distortion, between a pair of
pressing dies; pressing the metal matrix composite by the pressing
dies; and heating the metal matrix composite.
2. The method according to claim 1, further comprising the steps
of: placing ceramic particles in a forming die; injecting
pressurized molten matrix metal into the forming die; and
solidifying the matrix metal.
3. The method according to claim 2, wherein the molten metal matrix
is premixed with other ceramic particles.
4. The method according to claim 3, wherein other ceramic particles
are the same as the ceramic particles placed in the forming
die.
5. The method according to claim 3, wherein other ceramic particles
are different from the ceramic particles placed in the forming
die.
6. The method according to claim 1, wherein the holding step
includes alternately layering an intervening die and the plurality
of metal matrix composites.
7. The method according to claim 6, wherein the intervening die is
formed in the same shape as the pressing die as seen in the
pressing direction.
8. The method according to claim 6, wherein the intervening die is
formed larger than the pressing die as seen in the pressing
direction.
9. The method according to claim 6, wherein the intervening die is
formed smaller than the pressing die as seen in the pressing
direction and the intervening die is not smaller than the metal
matrix composites as seen in the pressing direction.
10. The method according to claim 6, wherein the intervening die
has a fin at its end.
11. The method according to claim 6, wherein the intervening die
includes a built-in heater.
12. The method according to claim 1, wherein the heating step is
performed at a temperature of ((Tm+273)/2-273) to (Tm-10).degree.
C., where Tm is the melting point of the matrix metal.
13. The method according to claim 1, wherein the heating step is
performed at a temperature of 10 to 150.degree. C. lower than the
melting point of the matrix metal.
14. The method according to claim 1, wherein the pressing step
includes applying a pressure of 1.5 to 65 MPa on the pressing
dies.
15. The method according to claim 1, wherein the matrix metal is
selected from the group consisting of aluminum, aluminum alloy,
copper, copper alloy, magnesium and magnesium alloy.
16. The method according to claim 1, wherein the ceramic is
selected from the group consisting of silicon carbide, aluminum
nitride, boron nitride, carbon and zirconia, either alone or in
mixture.
17. The method according to claim 1, wherein the heating step
includes putting the pressing dies that holds the metal matrix
composite therebetween in a furnace for heating.
18. The method according to claim 1, wherein the pressing die
includes a built-in heater.
19. The method according to claim 1, further comprising the step of
cooling the pressing dies.
20. The method according to claim 1, further comprising the step of
fastening the pressing dies.
21. The method according to claim 1, wherein the pressing die is
made of iron.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to a method of manufacturing
composite material and more particularly to a method of
manufacturing metal matrix composite with ceramic particles as a
disperse phase.
[0002] Metal matrix composites with ceramic particles as a disperse
phase can be manufactured by squeeze casting. Squeeze casting is
heating a matrix metal up to its melting point or above and
injecting the pressurized molten metal into the cavity of a die
with a disperse phase preplaced therein.
[0003] Unexamined Japanese patent application publication No.
2002-226925 has disclosed a method of manufacturing metal matrix
composite with ceramic particles as a disperse phase, in which the
composite has two different coefficients of expansion in the width
direction. In the above manufacturing method, pressurized molten
metal is injected into a die.
[0004] Unexamined Japanese patent application publication No.
2002-322531 has disclosed an aluminum matrix composite with ceramic
particles as a disperse phase and a manufacturing method thereof.
In the above manufacturing method, molten aluminum or aluminum
alloy of 690 to 700.degree. C. is injected into the cavity of a die
to fill any gaps among ceramic particles preplaced therein with
vacuum suction.
[0005] These squeeze castings are to inject pressurized molten
metal or to inject with vacuum suction into any gaps among ceramic
particles preplaced in the forming die, so that some composite
materials have a distortion due to bias of ceramic particles and/or
matrix metal, die deformation, desired shape of compact, conditions
of temperature, or the like.
[0006] To reduce distortion, various casting methods have been
studied so far, however, there has been no practical casting method
to completely eliminate such distortion. This distortion, for
example, causes some composite materials manufactured in a single
casting to be defective, with a consequence of low yield of raw
material. In addition, composite materials incorporating a large
amount of ceramics are very brittle, so that distortions are not
plastically deformed easily. For the above reasons, it has been a
difficult task to correct the distortion of composite
materials.
[0007] The present invention is directed to providing a method of
manufacturing metal matrix composite with ceramic particles as a
disperse phase, including a method of easily correcting the
distortion of the composite with no cracks produced therein.
SUMMARY OF THE INVENTION
[0008] In accordance with the present invention, a method of
manufacturing metal matrix composite with ceramic particles as a
disperse phase includes the steps of holding the single metal
matrix composite or the plurality of layered metal matrix
composites between a pair of pressing dies, pressing the metal
matrix composite by the pressing dies, and heating the metal matrix
composite.
[0009] Other aspects and advantages of the invention will become
apparent from the following description, taken in conjunction with
the accompanying drawings, illustrating by way of example the
principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The features of the present invention that are believed to
be novel are set forth with particularity in the appended claims.
The invention together with objects and advantages thereof, may
best be understood by reference to the following description of the
presently preferred embodiments together with the accompanying
drawings in which:
[0011] FIG. 1A is a schematic sectional view illustrating a
manufacturing process, in which ceramic particles are placed in a
forming die according to a first preferred embodiment of the
present invention;
[0012] FIG. 1B is a schematic sectional view illustrating a
manufacturing process, in which molten metal is injected into the
forming die according to the first preferred embodiment of the
present invention;
[0013] FIG. 1C is a schematic sectional view of a composite
material according to the first preferred embodiment of the present
invention;
[0014] FIG. 2A is a schematic view illustrating a distortion
correction process, in which a composite material is held between a
pair of pressing dies according to the first preferred embodiment
of the present invention;
[0015] FIG. 2B is a schematic view illustrating a distortion
correction process, in which the composite material is pressed by
the pressing dies according to the first preferred embodiment of
the present invention;
[0016] FIG. 2C is a schematic view illustrating a distortion
correction process, in which the pressing dies are fastened by die
dampers according to the first preferred embodiment of the present
invention;
[0017] FIG. 3A is a schematic view illustrating a distortion
correction process, in which a plurality of composite materials are
held between a set of pressing dies and intervening dies each
having the same shape as the pressing die as seen in the pressing
direction according to a second preferred embodiment of the present
invention;
[0018] FIG. 3B is a schematic view illustrating a distortion
correction process, in which a plurality of composite materials are
held between a set of pressing dies and intervening dies each
having a larger shape than the pressing die as seen in the pressing
direction according to a third preferred embodiment of the present
invention; and
[0019] FIG. 3C is a schematic view illustrating a distortion
correction process, in which a plurality of composite materials are
held between a set of pressing dies and intervening dies each
having a larger shape than the pressing die as seen in the pressing
direction and each having fins for heat sink and radiation,
provided at the ends according to a fourth preferred embodiment of
the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0020] The following will describe a method of manufacturing
composite material according to the first through fourth preferred
embodiments of the present invention with reference to FIGS. 1A
through 3C.
[0021] The manufacturing method according to the present invention
is directed to manufacturing metal matrix composite with ceramic
particles as a disperse phase, including a distortion correction
process. Furthermore, the manufacturing method according to the
present invention is directed to manufacturing metal matrix
composite with ceramic particles as a disperse phase, including a
manufacturing process and a distortion correction process.
[0022] Matrix metal is not limited if the metal is usable for
molten metal casting in forming composite material. The matrix
metal may be pure aluminum, aluminum alloy including Mg, Cu, Zn,
Si, Mn, or the like, pure copper, copper alloy including Ni, Sn,
Zn, Al, Pb, P, or the like, pure magnesium, and magnesium alloy
including Al, Zn, Mn, Zr, or the like. Especially, in terms of
thermal conductivity, aluminum, aluminum alloy, copper and copper
alloy are preferable.
[0023] Ceramic particles as a disperse phase are not limited if the
ceramic has a low thermal expansion. The ceramic of composite
material may be a single substance or a mixture of various kinds of
ceramics depending on application. The ceramic may be, for example,
silicon carbide, aluminum nitride, boron nitride, carbon and
zirconia, either alone or in mixture. In terms of thermal
conductivity, silicon carbide is preferable. The grain size of
ceramic particle is determined on properties required for composite
material. For example, a mixture of coarse particles and fine
particles may be used for tight filling. For example, coarse
particles having approximately 100 .mu.m in diameter and fine
particles having approximately 10 .mu.m in diameter may be
used.
[0024] The manufacturing process includes placing ceramic particles
in the forming die, injecting pressurized molten matrix metal into
the forming die and solidifying the matrix metal, thus
manufacturing a plate-like composite material. The term
"plate-like" not only includes the shape of a plate but also other
plate-like shapes that allow lamination thereof, such as tray-like
shape.
[0025] FIGS. 1A through 1C illustrate the above manufacturing
process. FIG. 1A is a schematic sectional view illustrating a
manufacturing process, in which ceramic particles are placed in a
forming die. FIG. 1B is a schematic sectional view illustrating a
manufacturing process, in which molten metal is injected into the
forming die. FIG. 1C is a schematic sectional view of a composite
material.
[0026] The following will describe the manufacturing process in
detail with reference to FIGS. 1A through 1C.
[0027] A die 4 which serves as a forming die is open top
box-shaped, having a plurality of disassemblable die components 4a,
4b fastened by bolts and nuts (not shown). The die 4 is made of a
material having a higher melting point than a matrix metal. For
example, the die 4 may be made of iron.
[0028] In the manufacturing process using the die 4, first, ceramic
particles 2 as a disperse phase are placed in the die 4, as shown
in FIG. 1A. Subsequently, pressurized molten matrix metal 3 is
injected into the die 4, as shown in FIG. 1B. The molten matrix
metal 3 is injected into the die 4 until it substantially fulfills
any gap among the ceramic particles 4 and forms the layer of molten
matrix metal with a specified amount to cover the ceramic particles
2 on the opening end of the die 4. Next, a head pressure
approximately equivalent to a pressure for die-casting (for
example, several dozen MPa to hundred MPa) is applied. The injected
molten metal 3 penetrates into any gap among the ceramic particles
2 preplaced in the die 4. Then, the die 4 is cooled to solidify the
molten metal 3. After the cooling, the die 4 is disassembled and
the composite material is taken out.
[0029] In FIGS. 1A through 1C, the shape of composite material is
plate-like, but it is not limited. Usage of a die having a cavity
of desired shape helps form a composite material in the desired
shape.
[0030] Molten metal may be premixed with other ceramic particles.
Other ceramic particles may be the same as the ceramic particles
preplaced in the die 4 or may be different therefrom. Premixed
ceramic particles in a molten metal help change the volume fraction
of disperse phase in the thickness direction of composite
material.
[0031] The distortion correction process includes holding a single
composite material or a plurality of layered composite materials
between a pair of pressing dies and heating the composite materials
under pressure.
[0032] FIGS. 2A through 2C illustrate the above distortion
correction process. FIG. 2A is a schematic view illustrating a
distortion correction process, in which a composite material having
a distortion is held in between a pair of pressing dies. FIG. 2B is
a schematic view illustrating a distortion correction process, in
which the composite material is pressed by the pressing dies. FIG.
2C is a schematic view illustrating a distortion correction
process, in which the pressing dies are fastened by die
clampers.
[0033] FIGS. 3A through 3C illustrate other distortion correction
processes using intervening dies for a plurality of composite
materials each having a distortion. FIG. 3A is a schematic view
illustrating a distortion correction process, in which a plurality
of composite materials are held between a set of pressing dies and
intervening dies each having the same shape as the pressing die as
seen in the pressing direction. FIG. 3B is a schematic view
illustrating a distortion correction process, in which a plurality
of composite materials are held between a set of pressing dies and
intervening dies each having a larger shape than the pressing die
as seen in the pressing direction. FIG. 3C is a schematic view
illustrating a distortion correction process, in which a plurality
of composite materials are held between a set of pressing dies and
intervening dies each having a larger shape than the pressing die
as seen in the pressing direction and each having fins for heat
sink and radiation, provided at the ends.
[0034] The following will describe a first preferred embodiment of
the distortion correction process according to the present
invention with reference to FIGS. 2A through 2C.
[0035] Referring to FIG. 2A, the composite material 1 having a
distortion is held between the pair of pressing dies 5. The
pressing dies 5 are made of a material having a higher melting
point than a matrix metal. For example, the pressing dies 5 may be
made of iron. Subsequently, as shown in FIG. 2B, the pressing dies
5 are pressurized toward each other in the thickness direction of
the composite material 1. A pressure of 1.5 to 65 MPa is applied on
the pressing dies 5. Next, as shown in FIG. 2C, the pressing dies 5
are fastened together by die dampers 6 at their peripheral
portions. Thus, the distortion correction process is performed for
a single composite material having a distortion.
[0036] FIGS. 3A through 3C each illustrate a manner of clamping
pressing dies in the distortion correction process for a plurality
of composite materials 1 according to second through fourth
preferred embodiments, respectively. As shown in FIGS. 3A through
3C, the composite materials 1 and the intervening dies 7 are
alternately layered and held by the pair of pressing dies 5.
[0037] The intervening dies 7 may be formed in the same shape as
the pressing die 5 as seen in the pressing direction or may be
formed in a larger shape than the pressing die 5 as seen in the
pressing direction. The intervening dies 7 are smaller than the
pressing dies 5 as seen in the pressing direction and they are not
smaller than the composite materials 1 as seen in the pressing
direction.
[0038] It is generally difficult to heat or cool the inner portion
between a pair of pressing dies, however, when the intervening dies
7 are larger than the pressing dies 5 as seen in the pressing
direction, it helps heat or radiate the inner portion. The
intervening dies 7 can have a fin 8 at their ends to help absorb or
radiate heat, as shown in FIG. 3C.
[0039] Now the clamped pressing dies 5 are directly put in a
furnace for heating. Heating is preferably performed at a
temperature of ((Tm+273)/2-273) to (Tm-10).degree. C., where Tm is
the melting point of the matrix metal. Specifically, the heating
temperature is preferably 10 to 150.degree. C. lower than the
melting point of the matrix metal. The pressing dies 5 and/or the
intervening dies 7 may include a built-in heater for heating.
Heating time depends upon heating temperature, however, it
preferably ranges from 30 minutes to 10 hours.
[0040] After the heating is finished, the pressing dies 5 are left
on an iron workbench or stool for cooling. Alternatively, the
pressing dies 5 may be cooled in the furnace with a longer time. As
may be necessary, it may be cooled rapidly. Finally, the pressing
dies 5 are disassembled and the composite materials 1 are taken
out.
[0041] The composite materials 1 as manufactured above may be used
as a heat sink for semiconductor device. These preferred
embodiments help correct the distortion of a composite material
with no cracks produced thereon. Composite materials having a
distortion were defective products so far, but they may be
corrected according to the preferred embodiments, with a
consequence of improved yield of raw material. These preferred
embodiments also help correct a plurality of composite materials
having a distortion at a time, so that it is efficient and
cost-effective in manufacturing.
EXAMPLE
[0042] The following will describe an example of a method of
manufacturing metal matrix composite material with ceramic
particles as a disperse phase.
[0043] First, an iron die was prepared. The die was preheated at a
temperature of 700.degree. C. for an hour in the furnace. The
preheated iron die had a temperature of approximately 280 to
300.degree. C. The punch was also preheated to a temperature of
approximately 280 to 300.degree. C.
[0044] 120 g of silicon carbide particles as ceramic particles
having a grain size of 100 .mu.m were placed in the die.
Subsequently, molten metal of foundry aluminum alloy AC4C having a
temperature of 650 to 700.degree. C. was injected into the die
through the upper opening thereof so as to substantially fill any
gaps among silicon carbide particles and cover the silicon carbide
particles on the opening end of the die. The molten metal had a
pressure of 100 MPa.
[0045] The injected molten metal penetrated into any gaps among the
silicon carbide particles preplaced in the die, and the molten
metal was then kept under a pressure of 100 MPa for three to six
minutes. After that, the die was naturally cooled and disassembled.
Thus, the plate-like composite materials having a 140-mm long and
100-mm wide rectangular broad surface were obtained. These
composite materials each had a distortion in their thickness
direction. The shapes of the distortions were various such as
convex, concave and waveform in the pressing direction.
[0046] The plate-like composite materials 1 having a convex
distortion in the pressing direction as shown in FIG. 2A were
placed on the upper surface of the stool parallel to the ground so
that the convex surface is directed upward, and the distortions
were measured by laser displacement gauge which is spaced upward
from the composite materials 1. A distance from the fixed laser
displacement gauge to the measured material was detected by laser
beam while the material was moved laterally on the stool.
Displacement detected while moving the material was measured as
distortion. Distortions of the composite materials may be caused by
uneven solidification, deformation due to preheated die, and
deformation due to stress in die during casting.
[0047] Next, the composite material having a distortion was held
between the pair of iron pressing dies, each having a 300-mm square
quadrate broad surface by 100-mm thick in rectangular
parallelepiped shape. In this example, the above-sized pressing
dies were used, but pressing dies having a 160-mm or above square
quadrate broad surface by 5-mm or above thick in rectangular
parallelepiped shape are applicable for composite materials having
the same size as the example.
[0048] The iron pressing dies were heated with the built-in heater.
The pressing dies were heated to a temperature of 400 to
500.degree. C. and pressurized to approximately 6.2 MPa with
handpress with the composite material held therebetween. The
pressing time was 30 minutes to 10 hours. The pressing time varies
for different temperatures. For example, it took 7 hours at a
temperature of 500.degree. C. The pressing dies were then naturally
cooled to room temperature, and the composite material was taken
out from the pressing dies.
[0049] The distortion of the composite material which had been 0.2
mm before distortion correction was 0.05 mm after distortion
correction. It has been demonstrated that distortion correction is
practicable.
[0050] The present examples and embodiments are to be considered as
illustrative and not restrictive, and the invention is not to be
limited to the details given herein but may be modified within the
scope of the appended claims.
* * * * *