U.S. patent application number 14/468745 was filed with the patent office on 2015-06-18 for method for producing nano-carbon composite.
The applicant listed for this patent is Hyundai Motor Company. Invention is credited to Jong Kook Lee, Byung Ho Min, Dong Hoon Nam.
Application Number | 20150167116 14/468745 |
Document ID | / |
Family ID | 53367701 |
Filed Date | 2015-06-18 |
United States Patent
Application |
20150167116 |
Kind Code |
A1 |
Min; Byung Ho ; et
al. |
June 18, 2015 |
METHOD FOR PRODUCING NANO-CARBON COMPOSITE
Abstract
A method for producing a nano-carbon composite is provided. The
method includes mixing nano-carbon powder and matrix alloy powder
by milling, to provide a mixed powder and substantially evenly
penetrating the nano-carbon powder inside of the matrix alloy by
milling the mixed powder. In addition, the method includes
clustering the mixed powder by milling the mixed powder slower than
in the penetrating process.
Inventors: |
Min; Byung Ho; (Suwon,
KR) ; Lee; Jong Kook; (Suwon, KR) ; Nam; Dong
Hoon; (Uiwang, KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Hyundai Motor Company |
Seoul |
|
KR |
|
|
Family ID: |
53367701 |
Appl. No.: |
14/468745 |
Filed: |
August 26, 2014 |
Current U.S.
Class: |
75/770 |
Current CPC
Class: |
C22C 26/00 20130101;
C22C 47/14 20130101; C22C 2026/002 20130101; C22C 21/00
20130101 |
International
Class: |
C22B 1/24 20060101
C22B001/24; C22B 7/00 20060101 C22B007/00 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 18, 2013 |
KR |
10-2013-0158796 |
Claims
1. A method for producing a nano-carbon composite, comprising:
mixing nano-carbon powder and matrix alloy powder by milling, to
provide a mixed powder; substantially evenly penetrating the
nano-carbon powder inside of the matrix alloy powder by milling the
mixed powder; and clustering the mixed powder by milling the mixed
powder slower than in the penetrating process.
2. The method for producing the nano-carbon composite of claim 1,
wherein the nano-carbon powder includes at least one of a group
selected of: carbon nano tube (CNT) and carbon nano fiber
(CNF).
3. The method for producing the nano-carbon composite of claim 1,
wherein the milling condition in the mixing step is about 40 to 60
RPM for about 8 to 11 hours.
4. The method for producing the nano-carbon composite of claim 1,
wherein the milling condition in the penetrating step is about 500
to 700 RPM for about 2 to 3 hours.
5. The method for producing the nano-carbon composite of claim 1,
wherein the milling RPM in the clustering step is about 75 to 85%
of the milling RPM in the penetrating step.
6. The method for producing the nano-carbon composite of claim 1,
wherein the milling condition in the clustering step is about 450
to 500 RPM for about 40 to 70 min.
7. The method for producing the nano-carbon composite of claim 1,
wherein the matrix alloy powder is aluminum alloy powder.
8. The method for producing the nano-carbon composite of claim 1,
wherein the nano-carbon composite includes particles in a size of
about 400 .mu.m or greater.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] The present application claims priority of Korean Patent
Application Number 10-2013-0158796 filed Dec. 18, 2013, the entire
contents of which application is incorporated herein for all
purposes by this reference.
TECHNICAL FIELD
[0002] The present invention relates to a method for producing a
nano-carbon composite, which secures easy oxidation and dispersion
thereof and minimizes damage and oxidation in molten metal of
carbon nano tube (CNT) or carbon nano fiber (CNF) by artificially
enlarging particle size of the nano composite powder through
milling condition change, in particular, by conducting ball
milling.
BACKGROUND
[0003] A typical aluminum composite in which CNT or CNF is
dispersed has been generally produced by sintering and extruding
processes through powder molding. Moreover, some composite for
casting has been produced by preparing composite powder to prevent
powder oxidation and floating; conducting intermediate process to
form the pellet; and charging the pellet in molten metal.
[0004] In particular, a typical method using the composite powder
generally produces a nano-carbon dispersed composite by preparing
composite powder of nano-carbon and matrix alloy through high
energy ball milling; preparing intermediate material in the form of
pellet (green compact) through sintering or press; and charging the
pellet in molten metal. However, the above-mentioned method may
raise problems, such as inefficiency and high production cost,
since the intermediate process for pellet preparation costs
additional time and efforts.
[0005] The description provided above as a related art of the
present invention is merely for helping understanding the
background of the present invention and should not be construed as
being included in the related art known by those skilled in the
art.
SUMMARY
[0006] The present invention provides a technical solution to the
above-described problems associated with conventional methods.
[0007] In one exemplary embodiment, the present invention provides
a method for producing a nano-carbon composite, which may include:
mixing nano-carbon powder and matrix alloy powder by milling, to
provide a mixed powder; substantially evenly penetrating the
nano-carbon powder inside of the matrix alloy by milling the mixed
powder; and clustering the mixed powder by milling the mixed powder
slower than in the penetrating step.
[0008] The nano-carbon powder may contain at least one of CNT and
CNF. The milling condition in the mixing step may be about 40 to 60
RPM for about 8 to 11 hours. The milling condition in the
penetrating step may be about 500 to 700 RPM for about 2 to 3
hours. The milling RPM in the coarsening step may be about 75 to
85% of the milling RPM in the penetrating step. The milling
condition in the coarsening step may be about 450 to 500 RPM for 40
to 70 min. The matrix alloy powder may be an aluminum alloy
powder.
[0009] In another exemplary embodiment, the nano-carbon composite
produced by the method of the present invention may include
particles in the size of about 400 .mu.m or greater.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The above and other features of the present invention will
now be described in detail with reference to certain exemplary
embodiments thereof illustrated the accompanying drawings which are
given hereinbelow by way of illustration only, and thus are not
limitative of the present invention, and wherein:
[0011] FIG. 1 is an exemplary microscopic view showing the
nano-carbon composite particles in the size of about 400 .mu.m or
less according to one exemplary embodiment of the present
invention;
[0012] FIG. 2 is an exemplary microscopic view showing the
nano-carbon composite particles in the size of about 400 .mu.m or
greater according to another exemplary embodiment of the present
invention;
[0013] FIG. 3 is an exemplary microscopic view showing CNT
penetrates inside of the matrix powder of the nano-carbon composite
according to one exemplary embodiment of the present invention;
and
[0014] FIG. 4 is an exemplary graph showing a correlation between
the hardness of particles and the particle size of the nano-carbon
composite according to one exemplary embodiment of the present
invention.
[0015] It should be understood that the appended drawings are not
necessarily to scale, presenting a somewhat simplified
representation of various exemplary features illustrative of the
basic principles of the invention. The specific design features of
the present invention as disclosed herein, including, for example,
specific dimensions, orientations, locations, and shapes will be
determined in part by the particular intended application and use
environment. In the figures, reference numbers refer to the same or
equivalent parts of the present invention throughout the several
figures of the drawing.
DETAILED DESCRIPTION
[0016] The terminology used herein is for the purpose of describing
particular embodiments only and is not intended to be limiting of
the invention. As used herein, the singular forms "a", "an" and
"the" are intended to include the plural forms as well, unless the
context clearly indicates otherwise. It will be further understood
that the terms "comprises" and/or "comprising," when used in this
specification, specify the presence of stated features, integers,
steps, operations, elements, and/or components, but do not preclude
the presence or addition of one or more other features, integers,
steps, operations, elements, components, and/or groups thereof. As
used herein, the term "and/or" includes any and all combinations of
one or more of the associated listed items.
[0017] Unless specifically stated or obvious from context, as used
herein, the term "about" is understood as within a range of normal
tolerance in the art, for example within 2 standard deviations of
the mean. "About" can be understood as within 10%, 9%, 8%, 7%, 6%,
5%, 4%, 3%, 2%, 1%, 0.5%, 0.1%, 0.05%, or 0.01% of the stated
value. Unless otherwise clear from the context, all numerical
values provided herein are modified by the term "about".
[0018] Hereinafter, the exemplary embodiments of the present
invention now will be described in detail with reference to the
accompanying drawings.
[0019] FIG. 1 is an exemplary microscopic view showing the
nano-carbon composite particles in the size of about 400 .mu.m or
less in one exemplary embodiment of the present invention; FIG. 2
is an exemplary microscopic view showing the nano-carbon composite
particles in the size of about 400 .mu.m or greater according to
another exemplary embodiment of the present invention; and FIG. 4
is an exemplary graph showing a correlation between the hardness of
particles and the particle size of the nano-carbon composite
according to one exemplary embodiment of the present invention.
[0020] In one exemplary embodiment of the present invention, the
method for producing the nano-carbon composite may include: a
mixing step for mixing nano-carbon powder and matrix alloy powder
by milling, to provide a mixed powder; a penetrating step for
substantial evenly penetrating of the nano-carbon powder inside of
the matrix alloy by milling the mixed powder; and a coarsening step
for clustering the mixed powder by milling the mixed powder slower
than in the penetrating step. In certain exemplary embodiments, the
nano-carbon powder may contain at least one of CNT and CNF.
[0021] In addition, the milling condition in the mixing step may be
about 40 to 60 RPM for 8 to 11 hours; and the milling condition in
the penetrating step may be about 500 to 700 RPM for about 2 to 3
hours. The milling RPM in the coarsening step may be about 75 to
85% of the milling RPM in the penetrating step. In addition, the
milling condition in the coarsening step may be about 450 to 500
RPM for about 40 to 70 min. The matrix alloy powder may be an
aluminum alloy powder and the nano-carbon composite produced by the
method of the present invention may include particles in the size
of about 400 .mu.m or greater.
[0022] According to the exemplary embodiment of the present
invention, the nano-carbon composite may be produced by a casting
process for mass production. In such a method, high energy ball
milling may be conducted using a mechanical mixing method to remove
an intermediate pellet process. Thus, oxidation and dispersion of
the nano composite may be more easily secured by artificially
enlarging particle size of the nano composite powder with changes
in milling condition. The present invention further provides such a
process which may minimize damage and oxidation in molten metal of
CNT or CNF.
[0023] In one exemplary embodiment of the present invention, the
method for producing coarse powder of the aluminum nano-carbon
composite in which a nano-carbon such as CNT or CNF is dispersed
may include: mixing CNT of about 10 to 15 wt % or CNF of about 10
to 15 wt % and aluminum alloy powder by a first slow milling at
about 50 RPM for 10 hour; milling of high energy ball milling (HEM)
at about 600 RPM for 2 to 3 hours; and milling at about 480 RPM,
which may be reduced for about 20% from the RPM of the second
milling, for 1 hour for powder coarsening. In particular, the first
slow milling may improve the clustered state of the CNT or CNF, and
the second high energy milling may penetrate the CNT/CNF inside the
aluminum powder using cold welding using high energy. The third
powder coarsening milling may obtain powder in the particle size of
about 400 .mu.m or greater by clustering aluminum powder.
[0024] Further, the nano composite powder may be charged while
stirring with molten metal, to produce aluminum composite for
casing in which the CNT/CNF may be dispersed. Therefore,
intermediate process for pellet processing may be removed by the
powder coarsening process. Accordingly, by the methods of the
exemplary embodiment of the present invention, mass production of
the nano-carbon composite may be simplified, the cost for
production thereof may be reduced, and a melting time may be
reduced by charging the powder itself in the molten metal.
[0025] FIG. 1 shows an exemplary microscopic view of particles in
the size of 400 .mu.m or less, and FIG. 2 shows exemplary composite
particles in the size of 400 .mu.m or greater according to the
exemplary embodiment of the present invention. Furthermore,
according to the exemplary embodiment of the present invention, CNT
may penetrate the matrix powder material as shown in FIG. 3.
[0026] Additionally, FIG. 4 is an exemplary graph showing a
correlation between the hardness of particles and the particle size
of the nano-carbon composite. As shown in FIG. 4, from the hardness
test results among a specimen produced by using pure aluminum, a
specimen produced using powder in the size of about 400 .mu.m or
less and a specimen produced by using powder in the size of about
400 .mu.m or greater, the hardness of the specimen produced using
powder in the size of about 400 .mu.m or greater is increased for
about 150% against the specimen of pure aluminum matrix, and is
equal to or greater than the hardness of the specimen produced
using powder in the size of about 400 tm or less.
[0027] According to the method for producing the nano-carbon
composite having the characters described above, in particular,
when conducting ball milling, oxidation and dispersion may be more
easily maintained by artificially enlarging particle sizes of the
nano composite powder through milling condition change, and damage
and oxidation in molten metal of CNT or CNF may be minimized. In
particular, since the intermediate pellet producing process may be
removed, the process efficiency may be improved, and time and cost
for producing the composite may be reduced.
[0028] The invention has been described in detail with reference to
exemplary embodiments thereof. However, it will be appreciated by
those skilled in the art that changes or modifications may be made
in these exemplary embodiments without departing from the
principles and spirit of the invention, the scope of which is
defined in the appended claims and their equivalents.
* * * * *