U.S. patent application number 11/279736 was filed with the patent office on 2007-03-15 for cutting segment, method for manufacturing cutting segment, and cutting tool comprising the same.
This patent application is currently assigned to GENERAL TOOL, INC.. Invention is credited to Soo-Kwang Kim, Hee-Dong Park.
Application Number | 20070056574 11/279736 |
Document ID | / |
Family ID | 37087251 |
Filed Date | 2007-03-15 |
United States Patent
Application |
20070056574 |
Kind Code |
A1 |
Kim; Soo-Kwang ; et
al. |
March 15, 2007 |
CUTTING SEGMENT, METHOD FOR MANUFACTURING CUTTING SEGMENT, AND
CUTTING TOOL COMPRISING THE SAME
Abstract
A cutting segment for a cutting tool used for cutting or
drilling brittle workpieces, such as stone, brick, concrete and
asphalt, a method for manufacturing the segment, and a cutting tool
comprising the segment are disclosed. The segment comprises layers
of diamond particles and two kinds of plate-shaped metal matrix
layers comprising soft and hard metal matrix layers having
different ductility. The plate-shaped metal matrix layers are
arranged perpendicular to a cutting surface while being parallel to
a cutting direction, and are alternately stacked perpendicular to
the cutting direction. The layers of diamond particles are suitably
arranged in the plate-shaped soft and hard metal matrix layers. The
segment and the cutting tool comprising the same have excellent
cutting ability, and the manufacturing process thereof can be
simplified, thereby remarkably enhancing productivity.
Inventors: |
Kim; Soo-Kwang; (Irvine,
CA) ; Park; Hee-Dong; (Sueon, KR) |
Correspondence
Address: |
BIRCH STEWART KOLASCH & BIRCH
PO BOX 747
FALLS CHURCH
VA
22040-0747
US
|
Assignee: |
GENERAL TOOL, INC.
Irvine
CA
EHWA DIAMOND INDUSTRIAL CO., LTD
Osan-City
|
Family ID: |
37087251 |
Appl. No.: |
11/279736 |
Filed: |
April 13, 2006 |
Current U.S.
Class: |
125/13.01 ;
125/15 |
Current CPC
Class: |
B24D 5/123 20130101;
B28D 1/121 20130101; B24D 99/005 20130101; B23D 61/18 20130101;
B23P 15/28 20130101 |
Class at
Publication: |
125/013.01 ;
125/015 |
International
Class: |
B28D 1/04 20060101
B28D001/04 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 14, 2005 |
KR |
10-2005-0031112 |
Claims
1. A cutting segment, comprising: a plurality of layers, each
comprising layers of diamond particles and two kinds of
plate-shaped metal matrix layers having different ductility,
wherein the two kinds of plate-shaped metal matrix layers are
arranged perpendicular to a cutting surface while being parallel to
a cutting direction, and are alternatively stacked perpendicular to
the cutting direction, and wherein each layer of diamond particles
has diamond particles surrounded by the metal matrix layer having
relatively high ductility among the metal matrix layers and
positioned in a row of diamond particles on the cutting
surface.
2. The segment according to claim 1, wherein the plate-shaped metal
matrix layers are constructed of a material selected from the group
consisting of steel, aluminum alloys, low melting point nickel
alloys, copper alloys, silver alloys, and brass.
3. The segment according to claim 2, wherein the plate-shaped metal
matrix layers comprise at least one plate-shaped hard metal matrix
layer and at least one plate-shaped soft metal matrix layer, the
plate-shaped hard metal matrix layer is constructed of steel, and
the plate-shaped soft metal matrix layer is constructed of a
material selected from the group consisting of aluminum alloys, low
melting point nickel alloys, copper alloys, silver alloys, and
brass.
4. The segment according to any one of claims 1 to 3, wherein the
plate-shaped metal matrix layers are constructed of a rolled
material, a sintered material, or a combination of a rolled
material and a sintered material.
5. The segment according to claim 4, wherein the plate-shaped metal
matrix layers are constructed of a rolled material.
6. The segment according to claim 5, wherein the rolled material is
a hot rolled steel plate or a cold rolled steel plate.
7. A cutting segment, comprising: a plurality of layers, each
comprising layers of diamond particles, and two kinds of
plate-shaped metal matrix layers comprising at least one soft metal
matrix layer having relatively high ductility and at least one hard
metal matrix layer having relatively low ductility, wherein the two
kinds of plate-shaped metal matrix layers are arranged
perpendicular to a cutting surface while being parallel to a
cutting direction, and are alternatively stacked perpendicular to
the cutting direction, and wherein each layer of diamond particles
has diamond particles, a portion of each diamond particle being
located in the soft metal matrix layer and the other portion of
each diamond particle being located in the hard metal matrix layer,
the diamond particles being positioned in a row of diamond
particles on the cutting surface.
8. The segment according to claim 7, wherein the portion of each
diamond particle of one layer of diamond particles is located in
each metal matrix layer.
9. The segment according to claim 8, wherein the soft metal matrix
layer has a thickness greater than that of the hard metal matrix
layer.
10. The segment according to claim 8, wherein the soft metal matrix
layer has a thickness smaller than that of the hard metal matrix
layer.
11. The segment according to claim 7, wherein the portion of each
diamond particle of two layers of diamond particles is located in
each metal matrix layer.
12. The segment according to any one of claims 7 to 11, wherein the
plate-shaped metal matrix layers are constructed of a material
selected from the group consisting of steel, aluminum alloys, low
melting point nickel alloys, copper alloys, silver alloys, and
brass.
13. The segment according to claim 12, wherein the plate-shaped
hard metal matrix layer is constructed of steel, and the
plate-shaped soft metal matrix layer is constructed of a material
selected from the group consisting of aluminum alloys, low melting
point nickel alloys, copper alloys, silver alloys, and brass.
14. The segment according to any one of claims 7 to 11, wherein the
plate-shaped metal matrix layers are constructed of a rolled
material, a sintered material, or a combination of a rolled
material and a sintered material.
15. The segment according to claim 12, wherein the plate-shaped
metal matrix layers are constructed of a rolled material, a
sintered material, or a combination of a rolled material and a
sintered material.
16. The segment according to claim 14, wherein the plate-shaped
metal matrix layers are constructed of a rolled material.
17. The segment according to claim 15, wherein the plate-shaped
metal matrix layers are constructed of a rolled material.
18. The segment according to claim 16 or 17, wherein the rolled
material is a hot rolled steel plate or a cold rolled steel
plate.
19. A method for manufacturing a cutting segment, comprising the
steps of: preparing two kinds of plate-shaped metal matrices
comprising plate-shaped soft metal matrices having relatively high
ductility and plate-shaped hard metal matrices having relatively
low ductility; arranging diamond particles on a first soft metal
matrix among the plate-shaped soft metal matrices such that the
diamond particles are positioned in a row of diamond particles on a
cutting surface; stacking a second soft metal matrix on the diamond
particles; stacking a first hard metal matrix among the
plate-shaped hard metal matrices on the second soft metal matrix;
stacking a third soft metal matrix on the first hard metal matrix,
followed by arranging other diamond particles on the third soft
metal matrix such that the other diamond particles are positioned
in a row of diamond particles on the cutting surface, stacking a
fourth soft metal matrix on the diamond particles, and stacking a
second hard metal matrix on the fourth soft metal matrix; repeating
the above steps to prepare a stack having a desired thickness; and
heating and compressing the stack such that components constituting
the stack are combined.
20. The method according to claim 19, wherein the plate-shaped
metal matrices are constructed of a material selected from the
group consisting of steel, aluminum alloys, low melting point
nickel alloys, copper alloys, silver alloys, and brass.
21. The method according to claim 20, wherein the plate-shaped hard
metal matrices are constructed of steel, and the plate-shaped soft
metal matrices are constructed of a material selected from the
group consisting of aluminum alloys, low melting point nickel
alloys, copper alloys, silver alloys, and brass.
22. The method according to claim 19, wherein the plate-shaped
metal matrices are constructed of a rolled material, a sintered
material, or a combination of the rolled material and the sintered
material.
23. The method according to claim 22, wherein the plate-shaped
metal matrices are constructed of the rolled material.
24. The method according to claim 23, wherein the rolled material
is a hot rolled steel plate or a cold rolled steel plate.
25. A method for manufacturing a cutting segment, comprising the
steps of: preparing two kinds of plate-shaped metal matrices
comprising plate-shaped soft metal matrices having relatively high
ductility and plate-shaped hard metal matrices having relatively
low ductility; arranging diamond particles on a first hard metal
matrix among the plate-shaped hard metal matrices such that the
diamond particles are positioned in a row of diamond particles on a
cutting surface; stacking a first soft metal matrix among the
plate-shaped soft metal matrices on the diamond particles; stacking
a second hard metal matrix on the first soft metal matrix, followed
by arranging other diamond particles on the second hard metal
matrix such that the other diamond particles are positioned in a
row of diamond particles on the cutting surface, and stacking a
second soft metal matrix on the diamond particles; repeating the
above steps to prepare a stack having a desired thickness; and
heating and compressing the stack such that components constituting
the stack are combined.
26. The method according to claim 25, wherein each plate-shaped
soft metal matrix layer of the stack has a thickness greater than
that of each plate-shaped hard metal matrix layer of the stack.
27. The method according to claim 25, wherein each plate-shaped
soft metal matrix layer of the stack has a thickness smaller than
that of each plate-shaped hard metal matrix layer of the stack.
28. The method according to claim 25, wherein the plate-shaped
metal matrices are constructed of a material selected from the
group consisting of steel, aluminum alloys, low melting point
nickel alloys, copper alloys, silver alloys, and brass.
29. The method according to claim 28, wherein the plate-shaped hard
metal matrices are constructed of steel, and the plate-shaped soft
metal matrices are constructed of a material selected from the
group consisting of aluminum alloys, low melting point nickel
alloys, copper alloys, silver alloys, and brass.
30. The method according to claim 25, wherein the plate-shaped
metal matrices are constructed of a rolled material, a sintered
material, or a combination of a rolled material and a sintered
material.
31. The method according to claim 28, wherein the plate-shaped
metal matrices are constructed of a rolled material, a sintered
material, or a combination of a rolled material and a sintered
material.
32. The method according to claim 30, wherein the plate-shaped
metal matrices are constructed of a rolled material.
33. The method according to claim 31, wherein the plate-shaped
metal matrices are constructed of a rolled material.
34. The method according to claim 32, wherein the rolled material
is a hot rolled steel plate or a cold rolled steel plate.
35. A method for manufacturing a cutting segment, comprising the
steps of: preparing two kinds of plate-shaped metal matrices
comprising plate-shaped soft metal matrices having relatively high
ductility and plate-shaped hard metal matrices having relatively
low ductility; arranging diamond particles on a first hard metal
matrix among the plate-shaped hard metal matrices such that the
diamond particles are positioned in a row of diamond particles on a
cutting surface; stacking a first soft metal matrix among the
plate-shaped soft metal matrices on the diamond particles;
arranging other diamond particles on the first soft metal matrix
such that the other diamond particles are positioned in a row of
diamond particles on the cutting surface, followed by stacking a
second hard metal matrix on the diamond particles, arranging other
diamond particles on the second hard metal matrix such that the
other diamond particles are positioned in a row of diamond
particles on the cutting surface, and stacking a third soft metal
matrix on the other diamond particles; repeating the above steps to
prepare a stack having a desired thickness; and heating and
compressing the stack such that components constituting the stack
are combined.
36. The method according to claim 35, wherein the plate-shaped
metal matrices are constructed of a material selected from the
group consisting of steel, aluminum alloys, low melting point
nickel alloys, copper alloys, silver alloys, and brass.
37. The method according to claim 36, wherein the plate-shaped hard
metal matrices are constructed of steel, and the plate-shaped soft
metal matrices are constructed of a material selected from the
group consisting of aluminum alloys, low melting point nickel
alloys, copper alloys, silver alloys, and brass.
38. The method according to claim 35, wherein the plate-shaped
metal matrices are constructed of a rolled material, a sintered
material, or a combination of a rolled material and a sintered
material.
39. The method according to claim 38, wherein the plate-shaped
metal matrices are constructed of a rolled material.
40. The method according to claim 39, wherein the rolled material
is a hot rolled steel plate or a cold rolled steel plate.
41. A cutting tool comprising the cutting segment according to
claim 1.
42. A cutting segment prepared according to the method of claim
19.
43. A cutting tool comprising the cutting segment according to
claim 42.
Description
RELATED APPLICATION
[0001] The present invention is based on, and claims priority from,
Korean Application Number 10-2005-0031112, filed on Apr. 14, 2005,
the disclosure of which is incorporated by reference herein in its
entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a cutting segment for a
cutting tool used for cutting or drilling brittle workpieces, such
as stone, brick, concrete and asphalt, a method for manufacturing
the segment, and a cutting tool comprising the segment. More
particularly, the present invention relates to a cutting segment
for a cutting tool, which uses a plate-shaped metal matrix instead
of a powdered metal matrix, a method of manufacturing the segment,
and a cutting tool comprising the segment.
[0004] 2. Description of the Related Art
[0005] In order to cut or drill brittle workpieces, such as stone,
brick, concrete and asphalt, it is necessary to provide an abrasive
material having hardness higher than that of the workpieces.
[0006] As for the abrasive material, synthetic diamond particles,
natural diamond particles, nitrogen boride and cemented carbide are
well known in the art, and particularly, the synthetic diamond
particles have been most widely used in the art of cutting tools
among these materials.
[0007] Synthetic diamond (referred to as "diamond" hereinafter) was
invented in the 1950's, and is known to have a higher hardness than
any other material on earth. Due to this property, diamond is
widely used for cutting tools, grinding tools and the like.
[0008] Particularly, the diamond has been widely used in the field
of stone machining when cutting or grinding a variety of stones,
such as marble, granite and the like, and in the field of
construction when cutting or grinding concrete structures.
[0009] A cutting segment (also referred to as "segment"
hereinafter) comprising diamond particles as the abrasive material,
and a cutting tool comprising the same will now be described.
[0010] Typically, a segment type diamond tool comprises a plurality
of segments, each having diamond particles distributed thereon, and
a steel core holding the segment.
[0011] FIG. 1 shows an example of the segment type diamond
tool.
[0012] Referring to FIG. 1, the segment type diamond tool comprises
a plurality of segments 11 and 12 fixed to a disk-shaped steel core
2 and having diamond particles 5 randomly distributed in each of
the segments 11 and 12.
[0013] The segments are manufactured according to powder
metallurgy, in which the diamond particles are mixed with metal
powders acting as a matrix, and are then compacted and
sintered.
[0014] As mentioned above, when the diamond particles are mixed
with the metal powders, the diamond particles are not uniformly
distributed among the metal powders, resulting in decreased cutting
efficiency of the diamond particles and reduction in life span.
[0015] That is, when mixing the diamond particles and the metal
powders acting as the matrix, differences in sizes and specific
gravities between the particles cause segregation of the diamond
particles, thereby generating non-uniform distribution of the
diamond particles among the metal powders. As a result, as shown in
FIG. 1, a cutting surface 3 in each segment with an excessively
large amount of diamond particles distributed thereon or a cutting
surface 4 with an excessively small amount of diamond particles
distributed thereon can be formed.
[0016] When the diamond particles are segregated as described
above, not only is the cutting efficiency of the cutting tool
deteriorated, but the life span of the cutting tool is also
reduced.
[0017] As a technology for solving the above problems caused by the
segregation of the diamond particles, a patterning technology,
which distributes the diamond particles in a predetermined pattern,
is suggested and an example thereof is illustrated in FIG. 2.
[0018] FIG. 2 shows another example of a segment type diamond tool
20 in which the diamond particles are distributed in the
predetermined pattern.
[0019] Referring to FIG. 2, each of the segments 21 and 22 has the
diamond particles 5 distributed thereon in the predetermined
pattern. That is, the diamond particles 5 are uniformly distributed
in each of the segments 21 and 22.
[0020] According to a patterning technology, instead of mixing the
metal powders and the diamond particles, the metal powders and the
diamond particles are arranged in layers by repeating a process for
arranging the diamond particles on the metal powder matrix in a
predetermined pattern and a process for positioning the metal
powder matrix on the diamond particles, and are then compacted into
a predetermined compact, followed by sintering, thereby providing
the segment.
[0021] Although the patterning technology for the diamond particles
can solve the problems caused by the segregation of the diamond
particles, intrinsic problems caused by the use of the powdered
metal matrix cannot be solved.
[0022] That is, when manufacturing the segment, if the metal
powders are used for the matrix, the metal powders are subjected to
a higher pressure during a process of compacting the metal matrix.
During the process of compacting the metal matrix, due to severe
wear of a compaction die by the diamond particles, variation in the
thickness of the matrix or breakage of the matrix frequently
occurs, thereby lowering productivity. Furthermore, in severe
cases, dimensions of the matrix are changed, so that the segments
have different dimensions, respectively, resulting in performance
variation and deterioration of the diamond tool.
[0023] Further, even though the metal powders for the matrix can be
manufactured by various methods using the same components,
manufacturing costs of the metal powders are remarkably high
compared with a bulk of metal having a different shape, such as
plate, coil, rod, and the like.
[0024] Additionally, when manufacturing the segments through powder
metallurgy, a process for mixing the diamond particles and the
metal powders, a process for compacting the mixture of the diamond
particles and the metal powders into a predetermined compact, and a
process for sintering the compact must be sequentially preformed,
complicating the manufacturing processes.
SUMMARY OF THE INVENTION
[0025] The present invention has been made to solve the above
problems, and it is an object of the present invention to provide a
cutting segment, which uses a metal plate instead of powdered metal
as a matrix, thereby realizing an excellent cutting ability, a
simplified manufacturing process and remarkably reduced
manufacturing costs.
[0026] It is another object of the present invention to provide a
method of manufacturing the segment as described above.
[0027] It is yet another object of the present invention to provide
a cutting tool comprising the segments as described above.
[0028] In accordance with one aspect of the present invention, the
above and other objects can be accomplished by the provision of a
cutting segment, comprising: a plurality of layers, each comprising
layers of diamond particles and two kinds of plate-shaped metal
matrix layers having different ductility, wherein the two kinds of
plate-shaped metal matrix layers are arranged perpendicular to a
cutting surface while being parallel to a cutting direction, and
are alternately stacked perpendicular to the cutting direction, and
wherein each layer of diamond particles has diamond particles
surrounded by the metal matrix layer having relatively high
ductility among the metal matrix layers and exhibited in a row of
diamond particles on the cutting surface.
[0029] In accordance with another aspect of the present, a cutting
segment is provided, comprising: a plurality of layers, each
comprising layers of diamond particles, and two kinds of
plate-shaped metal matrix layers comprising at least one soft metal
matrix layer having relatively high ductility and at least one hard
metal matrix layer having relatively low ductility, wherein the two
kinds of plate-shaped metal matrix layers are arranged
perpendicular to a cutting surface while being parallel to a
cutting direction, and are alternately stacked perpendicular to the
cutting direction, and wherein each layer of diamond particles has
diamond particles, a portion of each diamond particle being located
in the soft metal matrix layer and the other portion of each
diamond particle being located in the hard metal matrix layer, the
diamond particles being exhibited in a row of diamond particles on
the cutting surface.
[0030] The portion of each diamond particle of one layer of diamond
particles is located in each metal matrix layer.
[0031] The portion of each diamond particle of two layers of
diamond particles is located in each metal matrix layer.
[0032] In accordance with still another aspect of the present
invention, a method for manufacturing a cutting segment is
provided, comprising the steps of: preparing two kinds of
plate-shaped metal matrices comprising plate-shaped soft metal
matrices having relatively high ductility and plate-shaped hard
metal matrices having relatively low ductility; arranging diamond
particles on a first soft metal matrix among the plate-shaped soft
metal matrices such that the diamond particles are exhibited in a
row of diamond particles on a cutting surface; stacking a second
soft metal matrix on the diamond particles; stacking a first hard
metal matrix among the plate-shaped hard metal matrices on the
second soft metal matrix; stacking a third soft metal matrix on the
first hard metal matrix, followed by arranging other diamond
particles on the third soft metal matrix such that the other
diamond particles are exhibited in a row of diamond particles on
the cutting surface, stacking a fourth soft metal matrix on the
diamond particles, and stacking a second hard metal matrix on the
fourth soft metal matrix; repeating the above steps to prepare a
stack having a desired thickness; and heating and compressing the
stack such that components constituting the stack are combined.
[0033] In accordance with still another aspect of the present
invention, a method for manufacturing a cutting segment is
provided, comprising the steps of: preparing two kinds of
plate-shaped metal matrices comprising plate-shaped soft metal
matrices having relatively high ductility and plate-shaped hard
metal matrices having relatively low ductility; arranging diamond
particles on a first hard metal matrix among the plate-shaped hard
metal matrices such that the diamond particles are exhibited in a
row of diamond particles on a cutting surface; stacking a first
soft metal matrix among the plate-shaped soft metal matrices on the
diamond particles; stacking a second hard metal matrix on the first
soft metal matrix, followed by arranging other diamond particles on
the second hard metal matrix such that the other diamond particles
are exhibited in a row of diamond particles on the cutting surface,
and stacking a second soft metal matrix on the diamond particles;
repeating the above steps to prepare a stack having a desired
thickness; and heating and compressing the stack such that
components constituting the stack are combined.
[0034] In accordance with yet another aspect of the present
invention, a method for manufacturing a cutting segment is
provided, comprising the steps of: preparing two kinds of
plate-shaped metal matrices comprising plate-shaped soft metal
matrices having relatively high ductility and plate-shaped hard
metal matrices having relatively low ductility; arranging diamond
particles on a first hard metal matrix among the plate-shaped hard
metal matrices such that the diamond particles are exhibited in a
row of diamond particles on a cutting surface; stacking a first
soft metal matrix among the plate-shaped soft metal matrices on the
diamond particles; arranging other diamond particles on the first
soft metal matrix such that the other diamond particles are
exhibited in a row of diamond particles on the cutting surface,
followed by stacking a second hard metal matrix on the diamond
particles, arranging other diamond particles on the second hard
metal matrix such that the other diamond particles are exhibited in
a row of diamond particles on the cutting surface, and stacking a
second soft metal matrix on the other diamond particles; repeating
the above steps to prepare a stack having a desired thickness; and
heating and compressing the stack such that components constituting
the stack are combined.
BRIEF DESCRIPTION OF THE DRAWINGS
[0035] The above and other objects, features and other advantages
of the present invention will be more clearly understood from the
following detailed description taken in conjunction with the
accompanying drawings:
[0036] FIG. 1 is a diagram illustrating an example of a diamond
tool with diamond particles randomly distributed on a cutting
surface of a segment;
[0037] FIG. 2 is a diagram illustrating an example of a diamond
tool with the diamond particles uniformly distributed on the
cutting surface of the segment;
[0038] FIG. 3 is a diagram illustrating a cutting segment in
accordance with one embodiment of the present invention;
[0039] FIG. 4 is a diagram illustrating a cutting segment in
accordance with another embodiment of the present invention;
[0040] FIG. 5 is a diagram illustrating a cutting segment in
accordance with still another embodiment of the present
invention;
[0041] FIG. 6 is a diagram illustrating a cutting segment in
accordance with still another embodiment of the present
invention;
[0042] FIG. 7 is a diagram illustrating a cutting segment in
accordance with yet another embodiment of the present
invention;
[0043] FIG. 8 is a schematic diagram illustrating the arrangement
of components when manufacturing the segment in accordance with one
embodiment of the present invention;
[0044] FIG. 9 is a schematic diagram illustrating the arrangement
of components when manufacturing the segment in accordance with
another embodiment of the present invention; and
[0045] FIG. 10 is a schematic diagram illustrating the arrangement
of components when manufacturing the segment in accordance with yet
another embodiment of the present invention.
DESCRIPTION OF EMBODIMENTS OF THE INVENTION
[0046] Various embodiments within the scope of the invention will
now be described in detail with reference to the accompanying
drawings.
[0047] The present invention can be applied to a segment for a
cutting tool used for cutting or drilling brittle workpieces, such
as stone, brick, concrete and asphalt, and a cutting tool
comprising the segments.
[0048] The segment for the cutting tool comprises diamond particles
directly performing a cutting operation when cutting the
workpieces, and metal matrices holding the diamond particles.
[0049] Conventionally, powdered metal matrices have been used when
manufacturing the segment.
[0050] When manufacturing the segment using the powdered metal
matrices, there are problems in that the diamond particles are
segregated, reducing not only cutting efficiency of the cutting
tool, but also life span thereof.
[0051] Further, when manufacturing the segment using the powdered
metal matrices, a process of mixing the diamond particles and the
metal powders, a process of compacting the mixture of the diamond
particles and the powders into a predetermined compact, and a
process of sintering the compact must be sequentially carried
out.
[0052] Thus, when manufacturing the segment using the powdered
metal matrices, the manufacturing processes become complicated,
thereby increasing manufacturing costs.
[0053] As a technology for solving the above problems caused by
segregation of the diamond particles, a patterning technology,
which distributes the diamond particles in a predetermined pattern,
was suggested.
[0054] According to the patterning technology, instead of mixing
the metal powders and the diamond particles, after the powdered
metal matrices and the diamond particles are arranged in layers by
repeating a processes of arranging the diamond particles on a
powdered metal matrix in a predetermined pattern and then placing
another powdered metal matrix on the diamond particles, the layers
are compacted into a predetermined compact and sintered, thereby
producing the segment.
[0055] Although the patterning technology of the diamond particles
can solve the problems caused by the segregation of the diamond
particles, the problems of complicated manufacturing process and
increase in manufacturing costs caused by use of the powdered metal
matrices cannot be solved.
[0056] The principle of the invention is that plate-shaped metal
matrices are used from the beginning of the manufacturing process
instead of the powdered metal matrix.
[0057] If the segment is manufactured using the plate-shaped metal
matrices from the beginning of the process, not only are the
diamond particles distributed without segregation as is desired,
but also the manufacturing process can be simplified, thereby
minimizing the manufacturing costs.
[0058] Additionally, the principle of the invention is also that
two kinds of metal matrices having different ductility, that is,
soft metal matrices having relatively high ductility and hard metal
matrices having relatively high ductility, are used as the
plate-shaped metal matrices.
[0059] The segment of the invention comprises layers of diamond
particles, and two kinds of plate-shaped metal matrix layers having
different ductility, that is, soft metal matrix layers having
relatively high ductility and hard metal matrix layers having
relatively low ductility.
[0060] Herein, the term "soft" or "hard" refers not to an absolute
soft or hard value, but to a relative value between these metal
matrix layers.
[0061] The plate-shaped metal matrix layers are arranged
perpendicular to a cutting surface while being parallel to a
cutting direction, and are alternately stacked perpendicular to the
cutting direction.
[0062] Each layer of diamond particles has diamond particles
surrounded by the soft metal matrix layer having relatively high
ductility among the metal matrix layers.
[0063] In a segment in accordance with another embodiment, each
layer of diamond particles has diamond particles, a portion of each
diamond particle being located in the soft metal matrix layer
having relatively high ductility among the metal matrix layers and
the other portion of each diamond particle being located in the
hard metal matrix layer having relatively low ductility among the
metal matrix layers. At this time, it is desirable that a half or
more of the size of the diamond particle be located in the soft
metal matrix layer.
[0064] The segment of this embodiment is constructed such that the
thickness of the soft metal matrix layer is greater than that of
the hard metal matrix layer so as to allow a portion of each
diamond particle of one layer of diamond particles to be located in
each metal matrix layer.
[0065] Additionally, the segment of this embodiment is constructed
such that the thickness of the soft metal matrix layer is smaller
than that of the hard metal matrix layer so as to allow a portion
of each diamond particle of one layer of diamond particles to be
located in each metal matrix layer while allowing the portion of
each diamond particle to be surrounded by the soft metal matrix
layer.
[0066] In a segment in accordance with still another embodiment, a
portion of each diamond particle of two layers of diamond particles
is located in each metal matrix layer.
[0067] According to the invention, the plate-shaped metal matrix
layers consist of the two kinds of plate-shaped metal matrix layers
having different ductility, that is, the soft metal matrix layers
having relatively high ductility and the hard metal matrix layers
having relatively low ductility.
[0068] The metal matrix layer is can be constructed of a ferrous or
non-ferrous material, and alternatively of a material selected from
the group consisting of steel, aluminum alloys, low melting point
nickel alloys, copper alloys, silver alloys, and brass.
[0069] In another embodiment, the hard metal matrix layer is
constructed of steel, and the soft metal matrix layer is
constructed of a material selected from the group consisting of low
melting point nickel alloys, copper alloys, silver alloys, and
brass.
[0070] The plate-shaped metal matrix layers may be constructed of a
rolled material or a sintered material, and are preferably
constructed of the rolled material.
[0071] All of the plate-shaped metal matrix layers may be
constructed of the rolled material. Alternatively, some of the
plate-shaped metal matrix layers may be constructed of the sintered
material.
[0072] In yet another embodiment, the plate-shaped metal matrix
layers are constructed of a hot rolled steel plate or a cold rolled
steel plate.
[0073] The present invention will now be described in detail with
reference to the drawings.
[0074] FIG. 3 is a diagram illustrating an example of a cutting
segment according to the present invention.
[0075] Referring to FIG. 3, a cutting segment 100 of the invention
comprises layers of diamond particles 101, and two kinds of
plate-shaped metal matrix layers having different ductility, that
is, soft metal matrix layers 102 having relatively high ductility
and hard metal matrix layers 103 having relatively low
ductility.
[0076] The plate-shaped metal matrix layers 102 and 103 are
arranged perpendicular to a cutting surface while being parallel to
a cutting direction, and are alternately stacked perpendicular to
the cutting direction.
[0077] Each layer of diamond particles 101 has diamond particles
1011 surrounded by the soft metal matrix layer 102 having
relatively high ductility among the metal matrix layers.
[0078] Each layer of the diamond particles 101 is constructed such
that the diamond particles 1011 are exhibited as a row of diamond
particles on the cutting surface.
[0079] FIG. 4 is a diagram illustrating a segment 200 according to
another embodiment of the invention, in which layers of diamond
particle 201 are arranged on both sides of the segment shown in
FIG. 3.
[0080] Even if the thickness of the metal matrix layer having
relatively high ductility is smaller than that of the layer of
diamond particles, the metal matrix layers can surround the diamond
particles.
[0081] Accordingly, there is no restriction in the thickness of the
metal matrix layer having relatively high ductility. However, the
metal matrix layer having relatively high ductility is preferably
thinner than the layer of diamond particles.
[0082] Meanwhile, in a segment according to yet another embodiment
of the invention, each layer of diamond particles has diamond
particles, a portion of each diamond particle being located in the
soft metal matrix layer having relatively high ductility and the
other portion of each diamond particle being located in the hard
metal matrix layer having relatively low ductility among the metal
matrix layers.
[0083] FIGS. 5 to 7 show segments in accordance with other
embodiments of the invention, respectively.
[0084] As shown in FIG. 5, a cutting segment 300 according to
another embodiment of the invention comprises layers of diamond
particles 301, and two kinds of plate-shaped metal matrix layers
having different ductility, that is, soft metal matrix layers 302
having relatively high ductility and hard metal matrix layers 303
having relatively low ductility.
[0085] The plate-shaped metal matrix layers 302 and 303 are
arranged perpendicular to a cutting surface while being parallel to
a cutting direction, and are alternately stacked perpendicular to
the cutting direction.
[0086] Each layer of diamond particles 301 has diamond particles
3011, in which a portion of each diamond particle is located in the
soft metal matrix layer 302 and the other portion of each diamond
particle is located in the hard metal matrix layer 303.
[0087] The portion of each diamond particle 3011 of one layer of
diamond particles 301 is located in each metal matrix layer 302 or
303.
[0088] The thickness of the soft metal matrix layer 302 is greater
than that of the hard metal matrix layer 303.
[0089] Preferably, a half or more of the size of the diamond
particle in each diamond particle layer is located in the soft
metal matrix layer.
[0090] Each layer of diamond particles 301 is constructed such that
the diamond particles 3011 are exhibited as a row of diamond
particles on the cutting surface.
[0091] FIG. 6 shows a cutting segment according to still another
embodiment of the invention.
[0092] As shown in FIG. 6, a cutting segment 400 is different from
the cutting segment 300 of FIG. 5 in that the thickness of a soft
metal matrix layer 402 is smaller than that of a hard metal matrix
layer 403, and in that a portion of each diamond particle 4011
constituting a layer of diamond particles 401 is surrounded by the
soft metal matrix layer.
[0093] FIG. 7 shows a cutting segment according to yet another
embodiment of the invention.
[0094] As shown in FIG. 7, a cutting segment 500 is different from
the cutting segment 300 of FIG. 5 in that a portion of each diamond
particle 5011 of two layers of diamond particles 501 is located in
each metal matrix layer 502 and 503.
[0095] The soft metal matrix layer having relatively high ductility
preferably has a thickness greater than that of the hard metal
matrix layer, and greater than an average diameter of the diamond
particles.
[0096] As shown in FIG. 4, the layers of diamond particles 301, 401
and 501 may be located at both sides of the segments 300, 400 and
500, respectively.
[0097] In accordance with the invention, a cutting tool having the
segments as described above is provided.
[0098] One example of a method for manufacturing the segment
according to the invention will be described in detail with
reference to FIGS. 8 to 10.
[0099] Preparation of Plate-Shaped Metal Matrices
[0100] In order to manufacture a segment according to the
invention, two kinds of plate-shaped metal matrices constructed of
a ferrous or non-ferrous material having different ductility are
prepared.
[0101] That is, soft metal matrices having relatively high
ductility and hard metal matrices having relatively high ductility
must be prepared.
[0102] Each metal matrix is can be constructed of a ferrous or
non-ferrous material, and more preferably of a material selected
from the group consisting of steel, aluminum alloys, low melting
point nickel alloys, copper alloys, silver alloys, and brass.
[0103] In another embodiment, the hard metal matrices are
constructed of steel, and the soft metal matrices are constructed
of a material selected from the group consisting of the low melting
point nickel alloys, copper alloys, silver alloys, and brass.
[0104] The plate-shaped metal matrices are prepared to have a
suitable shape corresponding to the segment to be manufactured.
[0105] The plate-shaped metal matrices may be constructed of a
rolled material or a sintered material, and are particularly
constructed of the rolled material.
[0106] In one embodiment, the hard metal matrices are constructed
of a hot rolled steel plate or a cold rolled steel plate.
[0107] All of the plate-shaped metal matrices may be constructed of
the rolled material. Alternatively, some of the plate-shaped metal
matrices may be constructed of the sintered material.
[0108] When using the rolled material as the plate-shaped metal
matrices, the rolled material has a density near a theoretical
density limit. Accordingly, the segment using the rolled material
as each of the metal matrix exhibits excellent mechanical
properties, as compared with the segment produced by compacting and
sintering a powdered metal matrix.
[0109] Arrangement of Diamond Particles and Stacking of
Plate-Shaped Metal Matrices
[0110] In a method for manufacturing the segment according to one
embodiment of the invention, as shown in FIG. 8, diamond particles
6011 are arranged to form a layer of diamond particles 601 on a
first soft metal matrix 602 among the plate-shaped soft metal
matrices prepared as described above, and then a second soft metal
matrix 602' is stacked thereon.
[0111] Then, a first hard metal matrix 603 among the plate-shaped
hard metal matrices is stacked on the soft metal matrix 602', and a
third soft metal matrix 602'' is stacked on the first hard metal
matrix 603.
[0112] Other diamond particles 6011 are arranged to form another
layer of diamond particles 601 on the third soft metal matrix
602'', and a fourth soft metal matrix 602''' is stacked on the
other layer of diamond particles 601.
[0113] The above steps are repeated to provide a stack having a
desired thickness.
[0114] In this manner, a segment as shown in FIG. 3 can be
obtained.
[0115] In a method for manufacturing the segment according to
another embodiment of the invention, as shown in FIG. 9, diamond
particles 7011 are arranged to form a layer of diamond particles
701 on a first soft metal matrix 702 among the plate-shaped soft
metal matrices prepared as described above, and then a first hard
metal matrix 703 and a second soft metal matrix 702' are
sequentially stacked thereon.
[0116] Then, other diamond particles 7011 are arranged to form
another layer of diamond particles 701 on the second soft metal
matrix 702'', and then a second hard metal matrix 703' and a third
soft metal matrix 702'' are sequentially stacked thereon. These
steps are repeated to provide a stack having a desired
thickness.
[0117] In this manner, when the soft metal matrix 702, 702' or
702'' has a thickness greater than the hard metal matrix 703 or
703', a segment as shown in FIG. 5 can be obtained, and when the
soft metal matrix 702, 702' or 702'' has a thickness smaller than
the hard metal matrix 703 or 703', a segment as shown in FIG. 6 can
be obtained.
[0118] In a method for manufacturing the segment according to yet
another embodiment of the invention, as shown in FIG. 10, diamond
particles 8011 are arranged to form a layer of diamond particles
801 on a first soft metal matrix 802 among the plate-shaped soft
metal matrices prepared as described above, and then a first hard
metal matrix 803 is stacked thereon, followed by arranging other
diamond particles 8011 to form another layer of diamond particles
801.
[0119] Then, a second soft metal matrix 802'' is stacked on the
other layer of diamond particles 801, followed by arranging other
diamond particles 8011 to form still another layer of diamond
particles 801 and stacking a second hard metal matrix 803' thereon.
These steps are repeated to provide a stack having a desired
thickness.
[0120] In this manner, a segment as shown in FIG. 7 can be
obtained.
[0121] One example of a method for arranging the diamond particles
on the plate-shaped metal matrix as described above will be
described as follows.
[0122] First, spray type adhesives are applied onto a metal net cut
to have the shape of the segment, and then a metal jig punctured to
have holes uniformly spaced from each other by a laser is placed on
the spray type adhesives, followed by scattering fine diamond
particles thereon.
[0123] At this time, scattering of the fine diamond particles is
performed such that each of the holes formed on the metal jig must
receive one diamond particle.
[0124] By separating the metal jig therefrom, the metal net with
the diamond particles uniformly arranged thereon is obtained.
[0125] The diamond particles can be arranged on the plate-shaped
metal matrix by placing the metal net, having the diamond particles
uniformly arranged thereon as described above, on one of the
plate-shaped metal matrices.
[0126] As for another method of arranging the diamond particles,
there can be suggested a method of arranging the diamond particles
using a tape having an adhesive property.
[0127] Heating and Compressing the Stack
[0128] The laminate is heated and compressed such that components
constituting the laminate are combined with each other, thereby
providing the segment.
[0129] Unlike the powder compact, since the plate-shaped metal
matrix has 100% relative density, heating and compressing are
performed for combining the plate-shaped metal matrices.
[0130] Thus, it is not necessary to have the same conditions as
those of general sintering.
[0131] Combining temperature and pressure supply energy enables
metal elements on the surface of the plate-shaped metal matrix in
one layer to combine with the metal elements on the surface of the
plate-shaped metal matrix in different layers.
[0132] Sintering is generally carried out at a temperature of
700.about.1,000.degree. C. and a pressure of 350 kg/cm.sup.2 for 5
minutes, and according to the invention, combining of the
plate-shaped metal matrices is performed under these
conditions.
[0133] The conditions for combining the plate-shaped metal matrices
are varied according to not only the kind of the plate-shaped metal
matrix but also surface conditions of the metal matrix.
[0134] When using the rolled material as the plate-shaped metal
matrix, as a melting temperature of the rolled material is lowered
and the surface of the plate-shaped metal matrix is cleared without
an oxide film or extraneous substances, the combining temperature
and pressure are lowered and the time for combining is reduced.
[0135] When the layers of the diamond particles are inserted
between the plate-shaped metal matrices, a portion of each diamond
particle is stuck into the plate-shaped metal matrices during the
combining process.
[0136] When using the rolled material as the metal matrix, the
combining pressure is determined depending on the yield strength of
the plate-shaped metal matrix at a high temperature.
[0137] For instance, as the combining temperature is increased, the
yield strength of the plate-shaped metal matrix is lowered, causing
the combining pressure to be lowered in inverse proportion to the
combining temperature.
[0138] Since different kinds of plate-shaped metal matrices have
different melting points, they have different yield strengths at a
high temperature.
[0139] It is possible to adjust the position of the diamond
particles by adjusting a sintering temperature using such a
property.
[0140] For example, when using a relatively soft plate-shaped metal
matrix having a low melting point, the diamond particles are
shifted toward the plate-shaped soft metal matrix in a thickness
direction as is opposed to be shifted toward the relatively hard
plate-shaped metal matrix having a high melting point.
[0141] When using the hot rolled steel plate or the cold rolled
steel plate as the plate-shaped metal matrices, the yield strength
of the steel plate is continuously reduced in inverse proportion to
the temperature. Finally, the yield strength of the steel plate at
500.degree. C. is reduced to about a half of the yield strength at
room temperature, and most steel plates have a yield strength of 50
N/mm.sup.2 at 800.degree. C.
[0142] According to the experiment, it was found that at a
temperature of 800.degree. C. or more, the diamond particles were
sufficiently stuck into the plate-shaped metal matrices at a
pressure of 350 kg/cm.sup.2, which is a general pressure for
sintering.
[0143] If the relatively soft plate-shaped metal matrix has a
thickness smaller than that of the diamond particles, the soft
plate-shaped metal matrix is shifted towards the relatively hard
plate-shaped metal matrix in a state of surrounding the diamond
particles due to the high ductility thereof at high temperature. In
these cases, the segments are formed as shown in FIGS. 3, 4 and
6.
[0144] In accordance with the invention, a cutting tool having the
segments manufactured by the method as described above is
provided.
[0145] As apparent from the above description, according to the
present invention, there are advantageous effects in that as the
plate-shaped metal matrices are used instead of the powdered
matrices when manufacturing the cutting segment, manufacturing
costs are reduced, resulting in reduced product costs, and the
processes of mixing, granulating and forming of the metal matrices
are omitted, thereby simplifying the manufacturing process, and
thus remarkably enhancing productivity.
[0146] Further, there are advantageous effects in that as the
plate-shaped metal matrices are used instead of the powdered
matrices when manufacturing the segment, the diamond particles can
be uniformly distributed, thereby providing a segment having
excellent cutting ability and life span.
[0147] It should be understood that the embodiments and the
accompanying drawings have been described for illustrative
purposes, and the present invention is limited only by the
following claims. Further, those skilled in the art will appreciate
that various modifications, additions and substitutions are allowed
without departing from the scope and spirit of the invention
according to the accompanying claims.
* * * * *