U.S. patent application number 12/306524 was filed with the patent office on 2009-12-17 for abrasion resistant sintered copper base cu-ni-sn alloy and bearing made from the same.
This patent application is currently assigned to Mitsubishi Materials PMG Corporation. Invention is credited to Toshiro Harakawa, Tsuneo Maruyama, Teruo Shimizu.
Application Number | 20090311129 12/306524 |
Document ID | / |
Family ID | 38845553 |
Filed Date | 2009-12-17 |
United States Patent
Application |
20090311129 |
Kind Code |
A1 |
Harakawa; Toshiro ; et
al. |
December 17, 2009 |
ABRASION RESISTANT SINTERED COPPER BASE CU-NI-SN ALLOY AND BEARING
MADE FROM THE SAME
Abstract
A Cu--Ni--Sn copper-based sintered alloy has a composition
including 10 to 40% by mass of Ni, 5 to 25% by mass of Si, and the
remainder containing Cu and inevitable impurities, and if
necessary, 0.1 to 0.9% by mass of P, 1 to 10% by mass of C, 0.3 to
6% by mass of calcium fluoride or 0.3 to 6% by mass of molybdenum
disulfide. In the structure of the alloy, a phase of a composition
containing Cu.sub.(4-x-y)Ni.sub.xSn.sub.y (where x: 1.7 to 2.3, y:
0.2 to 1.3) is dispersed.
Inventors: |
Harakawa; Toshiro;
(Iwanuma-shi, JP) ; Shimizu; Teruo; (Tokyo,
JP) ; Maruyama; Tsuneo; (Niigata-shi, JP) |
Correspondence
Address: |
DARBY & DARBY P.C.
P.O. BOX 770, Church Street Station
New York
NY
10008-0770
US
|
Assignee: |
Mitsubishi Materials PMG
Corporation
Niigata-Ken
JP
|
Family ID: |
38845553 |
Appl. No.: |
12/306524 |
Filed: |
June 27, 2007 |
PCT Filed: |
June 27, 2007 |
PCT NO: |
PCT/JP2007/062841 |
371 Date: |
December 23, 2008 |
Current U.S.
Class: |
420/473 ;
420/587 |
Current CPC
Class: |
C22C 1/0425 20130101;
C22C 30/02 20130101; F16C 33/121 20130101; B22F 5/106 20130101;
C22C 9/06 20130101; F16C 2204/10 20130101 |
Class at
Publication: |
420/473 ;
420/587 |
International
Class: |
C22C 9/06 20060101
C22C009/06; C22C 30/02 20060101 C22C030/02 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 27, 2006 |
JP |
2006-176255 |
Claims
1. A Cu--Ni--Sn copper-based sintered alloy comprising a structure
in which a phase of a composition containing
Cu.sub.(4-x-y)Ni.sub.xSn.sub.y (where x: 1.7 to 2.3, y: 0.2 to 1.3)
is dispersed in a matrix of the Cu--Ni--Sn copper-based sintered
alloy containing Ni, Sn, and Cu.
2. A Cu--Ni--Sn copper-based sintered alloy comprising a
composition containing 10 to 40% by mass of Ni, 5 to 25% by mass of
Sn and the remainder containing Cu and inevitable impurities, and
having a structure in which a phase of a composition containing
Cu.sub.(4-x-y)Ni.sub.xSn.sub.y (where x: 1.7 to 2.3, y: 0.2 to 1.3)
is dispersed in a matrix.
3. A Cu--Ni--Sn copper-based sintered alloy comprising a
composition containing 10 to 40% by mass of Ni, 5 to 25% by mass of
Sn, 0.1 to 0.9% by mass of P and the remainder containing Cu and
inevitable impurities, and having a structure in which a phase of a
composition containing Cu.sub.(4-x-y)Ni.sub.xSn.sub.y (where x: 1.7
to 2.3, y: 0.2 to 1.3) and a phase of a composition containing
Cu.sub.(4-z)P.sub.z (where z: 0.7 to 1.3) are dispersed in a
matrix.
4. A Cu--Ni--Sn copper-based sintered alloy comprising a
composition containing 10 to 40% by mass of Ni, 5 to 25% by mass of
Sn, 1 to 10% by mass of C and the remainder containing Cu and
inevitable impurities, and having a structure in which a phase of a
composition containing Cu.sub.(4-x-y)Ni.sub.xSn.sub.y (where x: 1.7
to 2.3, y: 0.2 to 1.3) and a graphite phase are dispersed in a
matrix.
5. A Cu--Ni--Sn copper-based sintered alloy comprising a
composition containing 10 to 40% by mass of Ni, 5 to 25% by mass of
Sn, 0.1 to 0.9% by mass of P, 1 to 10% by mass of C and the
remainder containing Cu and inevitable impurities, and having a
structure in which a phase of a composition containing
Cu.sub.(4-x-y)Ni.sub.xSn.sub.y (where x: 1.7 to 2.3, y: 0.2 to
1.3), a phase of a composition containing Cu.sub.(4-z)P.sub.z
(where z: 0.7 to 1.3) and a graphite phase are dispersed in a
matrix.
6. A Cu--Ni--Sn copper-based sintered alloy comprising a
composition containing 10 to 40% by mass of Ni, 5 to 25% by mass of
Sn, 0.3 to 6% by mass of calcium fluoride and the remainder
containing Cu and inevitable impurities, and having a structure in
which a phase of a composition containing
Cu.sub.(4-x-y)Ni.sub.xSn.sub.y (where x: 1.7 to 2.3, y: 0.2 to 1.3)
and a calcium fluoride phase are dispersed in a matrix.
7. A Cu--Ni--Sn copper-based sintered alloy comprising a
composition containing 10 to 40% by mass of Ni, 5 to 25% by mass of
Sn, 0.1 to 0.9% by mass of P, 0.3 to 6% by mass of calcium fluoride
and the remainder containing Cu and inevitable impurities, and
having a structure in which a phase of a composition containing
Cu.sub.(4-x-y)Ni.sub.xSn.sub.y (where x: 1.7 to 2.3, y: 0.2 to
1.3), a phase of a composition containing Cu.sub.(4-z)P.sub.z
(where z: 0.7 to 1.3) and a calcium fluoride phase are dispersed in
a matrix.
8. A Cu--Ni--Sn copper-based sintered alloy comprising a
composition containing 10 to 40% by mass of Ni, 5 to 25% by mass of
Sn, 1 to 10% by mass of C, 0.3 to 6% by mass of calcium fluoride
and the remainder containing Cu and inevitable impurities, and
having a structure in which a phase of a composition containing
Cu.sub.(4-x-y)Ni.sub.xSn.sub.y (where x: 1.7 to 2.3, y: 0.2 to
1.3), a graphite phase and a calcium fluoride phase are dispersed
in a matrix.
9. A Cu--Ni--Sn copper-based sintered alloy comprising a
composition containing 10 to 40% by mass of Ni, 5 to 25% by mass of
Sn, 0.1 to 0.9% by mass of P, 1 to 10% by mass of C, 0.3 to 6% by
mass of calcium fluoride and the remainder containing Cu and
inevitable impurities, and having a structure in which a phase of a
composition containing Cu.sub.(4-x-y)Ni.sub.xSn.sub.y (where x: 1.7
to 2.3, y: 0.2 to 1.3), a phase of a composition containing
Cu.sub.(4-z)P.sub.z (where z: 0.7 to 1.3), a graphite phase and a
calcium fluoride phase are dispersed in a matrix.
10. A Cu--Ni--Sn copper-based sintered alloy comprising a
composition containing 10 to 40% by mass of Ni, 5 to 25% by mass of
Sn, 0.3 to 6% by mass of molybdenum disulfide and the remainder
containing Cu and inevitable impurities, and having a structure in
which a phase of a composition containing
Cu.sub.(4-x-y)Ni.sub.xSn.sub.y (where x: 1.7 to 2.3, y: 0.2 to 1.3)
and a molybdenum disulfide phase are dispersed in a matrix.
11. A Cu--Ni--Sn copper-based sintered alloy comprising a
composition containing 10 to 40% by mass of Ni, 5 to 25% by mass of
Sn, 0.1 to 0.9% by mass of P, 0.3 to 6% by mass of molybdenum
disulfide and the remainder containing Cu and inevitable
impurities, and having a structure in which a phase of a
composition containing Cu.sub.(4-x-y)Ni.sub.xSn.sub.y (where x: 1.7
to 2.3, y: 0.2 to 1.3), a phase of a composition containing
Cu.sub.(4-z)P.sub.z (where z: 0.7 to 1.3) and a molybdenum
disulfide phase are dispersed in a matrix.
12. A Cu--Ni--Sn copper-based sintered alloy comprising a
composition containing 10 to 40% by mass of Ni, 5 to 25% by mass of
Sn, 1 to 10% by mass of C, 0.3 to 6% by mass of molybdenum
disulfide and the remainder containing Cu and inevitable
impurities, and having a structure in which a phase of a
composition containing Cu.sub.(4-x-y)Ni.sub.xSn.sub.y (where x: 1.7
to 2.3, y: 0.2 to 1.3), a graphite phase and a molybdenum disulfide
phase are dispersed in a matrix.
13. A Cu--Ni--Sn copper-based sintered alloy comprising a
composition containing 10 to 40% by mass of Ni, 5 to 25% by mass of
Sn, 0.1 to 0.9% by mass of P, 1 to 10% by mass of C, 0.3 to 6% by
mass of molybdenum disulfide and the remainder containing Cu and
inevitable impurities, and having a structure in which a phase of a
composition containing Cu.sub.(4-x-y)Ni.sub.xSn.sub.y (where x: 1.7
to 2.3, y: 0.2 to 1.3), a phase of a composition containing
Cu.sub.(4-z)P.sub.z (where z: 0.7 to 1.3), a graphite phase and a
molybdenum disulfide phase are dispersed in a matrix.
14. A Cu--Ni--Sn copper-based sintered alloy comprising a
composition containing 10 to 40% by mass of Ni, 5 to 25% by mass of
Sn, 0.3 to 6% by mass of calcium fluoride, 0.3 to 6% by mass of
molybdenum disulfide and the remainder containing Cu and inevitable
impurities, and having a structure in which a phase of a
composition containing Cu.sub.(4-x-y)Ni.sub.xSn.sub.y (where x: 1.7
to 2.3, y: 0.2 to 1.3), a calcium fluoride phase and a molybdenum
disulfide phase are dispersed in a matrix.
15. A Cu--Ni--Sn copper-based sintered alloy comprising a
composition containing 10 to 40% by mass of Ni, 5 to 25% by mass of
Sn, 0.1 to 0.9% by mass of P, 0.3 to 6% by mass of calcium
fluoride, 0.3 to 6% by mass of molybdenum disulfide and the
remainder containing Cu and inevitable impurities, and having a
structure in which a phase of a composition containing
Cu.sub.(4-x-y)Ni.sub.xSn.sub.y (where x: 1.7 to 2.3, y: 0.2 to
1.3), a phase of a composition containing Cu.sub.(4-z)P.sub.z
(where z: 0.7 to 1.3), a calcium fluoride phase and a molybdenum
disulfide phase are dispersed in a matrix.
16. A Cu--Ni--Sn copper-based sintered alloy comprising a
composition containing 10 to 40% by mass of Ni, 5 to 25% by mass of
Sn, 1 to 10% by mass of C, 0.3 to 6% by mass of calcium fluoride,
0.3 to 6% by mass of molybdenum disulfide and the remainder
containing Cu and inevitable impurities, and having a structure in
which a phase of a composition containing
Cu.sub.(4-x-y)Ni.sub.xSn.sub.y (where x: 1.7 to 2.3, y: 0.2 to
1.3), a graphite phase, a calcium fluoride phase and a molybdenum
disulfide phase are dispersed in a matrix.
17. A Cu--Ni--Sn copper-based sintered alloy comprising a
composition containing 10 to 40% by mass of Ni, 5 to 25% by mass of
Sn, 0.1 to 0.9% by mass of P, 1 to 10% by mass of C, 0.3 to 6% by
mass of calcium fluoride, 0.3 to 6% by mass of molybdenum disulfide
and the remainder containing Cu and inevitable impurities, and
having a structure in which a phase of a composition containing
Cu.sub.(4-x-y)Ni.sub.xSn.sub.y (where x: 1.7 to 2.3, y: 0.2 to
1.3), a phase of a composition containing Cu.sub.(4-z)P.sub.z
(where z: 0.7 to 1.3), a graphite phase, a calcium fluoride phase
and a molybdenum disulfide phase are dispersed in a matrix.
18. A bearing which is made of the Cu--Ni--Sn copper-based sintered
alloy according to claim 1.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This is a U.S. national phase application under 35 U.S.C.
.sctn. 371 of International Patent Application No.
PCT/JP2007/062841, filed Jun. 27, 2007 and claims the benefit of
Japanese Application 2006-176255, filed Jun. 27, 2006. The
International Application was published on Jan. 3, 2008 as
International Publication No. WO 2008/001789 under PCT Article
21(2) the contents of which are incorporated herein in their
entirety.
TECHNICAL FIELD
[0002] The present invention relates to a Cu--Ni--Sn copper-based
sintered alloy for bearings, having excellent friction properties
and wear resistance, and a bearing made of the alloy.
BACKGROUND
[0003] A Cu--Ni--Sn copper-based sintered alloy has been used for
bearings in the past. Particularly, since the Cu--Ni--Sn
copper-based sintered alloy exhibits excellent friction properties
and wear resistance in a high-temperature environment, the alloy
has been used for, for example, a bearing of a stainless steel
reciprocating shaft, which operates the recirculation exhaust gas
flow rate control valve of an EGR type internal combustion engine
(e.g. see JP-A-2004-68074), or inner and outer rotors of an
internal gear pump (e.g. see JP-A-2005-314807), as they are
required to have friction properties and wear resistance even in a
high-temperature environment.
[0004] Moreover, it is known to add a solid lubricant, such as
molybdenum disulfide, so as to improve lubricating properties by
lowering the friction coefficient of a bearing made of the
Cu--Ni--Sn copper-based sintered alloy. The amount of molybdenum
disulfide added for improving the lubricating properties of a
Cu--Ni--Sn copper-based sintered alloy is generally in the range of
1% to 5%.
SUMMARY OF THE INVENTION
[0005] Since the above-mentioned Cu--Ni--Sn copper-based sintered
alloy has a relatively large amount of Ni, the alloy has excellent
strength, corrosion resistance, friction properties and wear
resistance. Particularly, under a high-temperature environment, the
alloy exhibits excellent friction properties and wear resistance.
However, the alloy needs to be further improved in friction
properties and wear resistance.
[0006] Therefore, the inventors of the invention studied to improve
the friction properties and wear resistance of the above-mentioned
Cu--Ni--Sn copper-based sintered alloy. As a result, the inventors
have found that friction properties and wear resistance can be
improved by forming a structure in which a phase of a composition
containing Cu.sub.(4-x-y)Ni.sub.xSn.sub.y (where x: 1.7 to 2.3, y:
0.2 to 1.3) is dispersed in a matrix of the Cu--Ni--Sn copper-based
sintered alloy.
[0007] The invention is embodied on the basis of the results of the
study.
[0008] (1) The invention relates to a Cu--Ni--Sn copper-based
sintered alloy having excellent friction properties and wear
resistance, and the alloy has a structure in which a phase of a
composition containing Cu.sub.(4-x-y)Ni.sub.xSn.sub.y (where x: 1.7
to 2.3, y: 0.2 to 1.3) is dispersed in a matrix of the Cu--Ni--Sn
copper-based sintered alloy containing Ni, Sn and Cu. It is
preferable that x is in the range of 1.7 to 2.2 and y is in the
range of 0.8 to 1.3.
[0009] The Cu--Ni--Sn copper-based sintered alloy containing Ni, Sn
and Cu according to (1) may be a Cu--Ni--Sn copper-based sintered
alloy which has a composition including 10 to 40% by mass of Ni, 5
to 25% by mass of Sn, and the remainder containing Cu and
inevitable impurities, and if necessary, 0.1 to 0.9% by mass of P
and/or 1 to 10% by mass of C. When the composition includes 0.1 to
0.9% by mass of P and/or 1 to 10% by mass of C, a phase of a
composition containing Cu.sub.(4-z)P.sub.z (where z: 0.7 to 1.3)
and/or a graphite phase are/is produced on the matrix of the
Cu--Ni--Sn copper-based sintered alloy.
[0010] Accordingly, the invention has the following
characteristics.
[0011] (2) A Cu--Ni--Sn copper-based sintered alloy having
excellent friction properties and wear resistance. The alloy has a
composition containing 10 to 40% by mass of Ni, 5 to 25% by mass of
Sn and the remainder containing Cu and inevitable impurities, and
has a structure in which a phase of a composition containing
Cu.sub.(4-x-y)Ni.sub.xSn.sub.y (where x: 1.7 to 2.3, y: 0.2 to 1.3)
is dispersed in a matrix.
[0012] (3) A Cu--Ni--Sn copper-based sintered alloy having
excellent friction properties and wear resistance. The alloy has a
composition containing 10 to 40% by mass of Ni, 5 to 25% by mass of
Sn, 0.1 to 0.9% by mass of P and the remainder containing Cu and
inevitable impurities, and has a structure in which a phase of a
composition containing Cu.sub.(4-x-y)Ni.sub.xSn.sub.y (where x: 1.7
to 2.3, y: 0.2 to 1.3) and a phase of a composition containing
Cu.sub.(4-z)P.sub.z (where z: 0.7 to 1.3) are dispersed in a
matrix.
[0013] (4) A Cu--Ni--Sn copper-based sintered alloy having
excellent friction properties and wear resistance. The alloy has a
composition containing 10 to 40% by mass of Ni, 5 to 25% by mass of
Sn, 1 to 10% by mass of C and the remainder containing Cu and
inevitable impurities, and has a structure in which a phase of a
composition containing Cu.sub.(4-x-y)Ni.sub.xSn.sub.y (where x: 1.7
to 2.3, y: 0.2 to 1.3) and a graphite phase are dispersed in a
matrix.
[0014] (5) A Cu--Ni--Sn copper-based sintered alloy having
excellent friction properties and wear resistance. The alloy has a
composition containing 10 to 40% by mass of Ni, 5 to 25% by mass of
Sn, 0.1 to 0.9% by mass of P, 1 to 10% by mass of C and the
remainder containing Cu and inevitable impurities, and has a
structure in which a phase of a composition containing
Cu.sub.(4-x-y)Ni.sub.xSn.sub.y (where x: 1.7 to 2.3, y: 0.2 to
1.3), a phase of a composition containing Cu.sub.(4-z)P.sub.z
(where z: 0.7 to 1.3) and a graphite phase are dispersed in a
matrix.
[0015] For the ranges described above, Ni is preferably in the
range of 15 to 30% by mass, Sn is preferably in the range of 6 to
15% by mass, P is preferably in the range of 0.1 to 0.5% by mass, C
is preferably in the range of 3 to 9% by mass, and z is preferably
in the range of 0.9 to 1.2.
[0016] The Cu--Ni--Sn copper-based sintered alloy containing Ni, Sn
and Cu according to any one of (2) to (5) may further include, if
necessary, 0.3 to 6% by mass of calcium fluoride. A calcium
fluoride phase is dispersed in a matrix of the Cu--Ni--Sn
copper-based sintered alloy including the calcium fluoride.
Accordingly, the invention has the following characteristics.
[0017] (6) A Cu--Ni--Sn copper-based sintered alloy having
excellent friction properties and wear resistance. The alloy has a
composition containing 10 to 40% by mass of Ni, 5 to 25% by mass of
Sn, 0.3 to 6% by mass of calcium fluoride and the remainder
containing Cu and inevitable impurities, and has a structure in
which a phase of a composition containing
Cu.sub.(4-x-y)Ni.sub.xSn.sub.y (where x: 1.7 to 2.3, y: 0.2 to 1.3)
and a calcium fluoride phase are dispersed in a matrix.
[0018] (7) A Cu--Ni--Sn copper-based sintered alloy having
excellent friction properties and wear resistance. The alloy has a
composition containing 10 to 40% by mass of Ni, 5 to 25% by mass of
Sn, 0.1 to 0.9% by mass of P, 0.3 to 6% by mass of calcium fluoride
and the remainder containing Cu and inevitable impurities, and has
a structure in which a phase of a composition containing
Cu.sub.(4-x-y)Ni.sub.xSn.sub.y (where x: 1.7 to 2.3, y: 0.2 to
1.3), a phase of a composition containing Cu.sub.(4-z)P.sub.z
(where z: 0.7 to 1.3) and a calcium fluoride phase are dispersed in
a matrix.
[0019] (8) A Cu--Ni--Sn copper-based sintered alloy having
excellent friction properties and wear resistance. The alloy has a
composition containing 10 to 40% by mass of Ni, 5 to 25% by mass of
Sn, 1 to 10% by mass of C, 0.3 to 6% by mass of calcium fluoride
and the remainder containing Cu and inevitable impurities, and has
a structure in which a phase of a composition containing
Cu.sub.(4-x-y)Ni.sub.xSn.sub.y (where x: 1.7 to 2.3, y: 0.2 to
1.3), a graphite phase and a calcium fluoride phase are dispersed
in a matrix.
[0020] (9) A Cu--Ni--Sn copper-based sintered alloy having
excellent friction properties and wear resistance. The alloy has a
composition containing 10 to 40% by mass of Ni, 5 to 25% by mass of
Sn, 0.1 to 0.9% by mass of P, 1 to 10% by mass of C, 0.3 to 6% by
mass of calcium fluoride and the remainder containing Cu and
inevitable impurities, and has a structure in which a phase of a
composition containing Cu.sub.(4-x-y)Ni.sub.xSn.sub.y (where x: 1.7
to 2.3, y: 0.2 to 1.3), a phase of a composition containing
Cu.sub.(4-z)P.sub.z (where z: 0.7 to 1.3), a graphite phase and a
calcium fluoride phase are dispersed in a matrix.
[0021] For the range described above, calcium fluoride is
preferably in the range of 0.5 to 5% by mass.
[0022] The Cu--Ni--Sn copper-based sintered alloy containing Ni, Sn
and Cu according to any one of (2) to (5) may further include, if
necessary, 0.3 to 6% by mass of molybdenum disulfide. A molybdenum
disulfide phase is dispersed in a matrix of the Cu--Ni--Sn
copper-based sintered alloy including the molybdenum disulfide.
Accordingly, the invention has the following characteristics.
[0023] (10) A Cu--Ni--Sn copper-based sintered alloy having
excellent friction properties and wear resistance. The alloy has a
composition containing 10 to 40% by mass of Ni, 5 to 25% by mass of
Sn, 0.3 to 6% by mass of molybdenum disulfide and the remainder
containing Cu and inevitable impurities, and has a structure in
which a phase of a composition containing
Cu.sub.(4-x-y)Ni.sub.xSn.sub.y (where x: 1.7 to 2.3, y: 0.2 to 1.3)
and a molybdenum disulfide phase are dispersed in a matrix.
[0024] (11) A Cu--Ni--Sn copper-based sintered alloy having
excellent friction properties and wear resistance. The alloy has a
composition containing 10 to 40% by mass of Ni, 5 to 25% by mass of
Sn, 0.1 to 0.9% by mass of P, 0.3 to 6% by mass of molybdenum
disulfide and the remainder containing Cu and inevitable
impurities, and has a structure in which a phase of a composition
containing Cu.sub.(4-x-y)Ni.sub.xSn.sub.y (where x: 1.7 to 2.3, y:
0.2 to 1.3), a phase of a composition containing
Cu.sub.(4-z)P.sub.z (where z: 0.7 to 1.3) and a molybdenum
disulfide phase are dispersed in a matrix.
[0025] (12) A Cu--Ni--Sn copper-based sintered alloy having
excellent friction properties and wear resistance. The alloy has a
composition containing 10 to 40% by mass of Ni, 5 to 25% by mass of
Sn, 1 to 10% by mass of C, 0.3 to 6% by mass of molybdenum
disulfide and the remainder containing Cu and inevitable
impurities, and has a structure in which a phase of a composition
containing Cu.sub.(4-x-y)Ni.sub.xSn.sub.y (where x: 1.7 to 2.3, y:
0.2 to 1.3), a graphite phase and a molybdenum disulfide phase are
dispersed in a matrix.
[0026] (13) A Cu--Ni--Sn copper-based sintered alloy having
excellent friction properties and wear resistance. The alloy has a
composition containing 10 to 40% by mass of Ni, 5 to 25% by mass of
Sn, 0.1 to 0.9% by mass of P, 1 to 10% by mass of C, 0.3 to 6% by
mass of molybdenum disulfide and the remainder containing Cu and
inevitable impurities, and has a structure in which a phase of a
composition containing Cu.sub.(4-x-y)Ni.sub.xSn.sub.y (where x: 1.7
to 2.3, y: 0.2 to 1.3), a phase of a composition containing
Cu.sub.(4-z)P.sub.z (where z: 0.7 to 1.3), a graphite phase and a
molybdenum disulfide phase are dispersed in a matrix.
[0027] For the range described above, molybdenum disulfide is
preferably in the range of 0.5 to 5% by mass.
[0028] The Cu--Ni--Sn copper-based sintered alloy containing Ni, Sn
and Cu according to any one of (2) to (5) may further include, if
necessary, 0.3 to 6% by mass of calcium fluoride and 0.3 to 6% by
mass of molybdenum disulfide. A calcium fluoride phase and a
molybdenum disulfide phase are dispersed in a matrix of the
Cu--Ni--Sn copper-based sintered alloy including the calcium
fluoride and the molybdenum disulfide. Accordingly, the invention
has the following characteristics.
[0029] (14) A Cu--Ni--Sn copper-based sintered alloy having
excellent friction properties and wear resistance. The alloy has a
composition containing 10 to 40% by mass of Ni, 5 to 25% by mass of
Sn, 0.3 to 6% by mass of calcium fluoride, 0.3 to 6% by mass of
molybdenum disulfide and the remainder containing Cu and inevitable
impurities, and has a structure in which a phase of a composition
containing Cu.sub.(4-x-y)Ni.sub.xSn.sub.y (where x: 1.7 to 2.3, y:
0.2 to 1.3), a calcium fluoride phase and a molybdenum disulfide
phase are dispersed in a matrix.
[0030] (15) A Cu--Ni--Sn copper-based sintered alloy having
excellent friction properties and wear resistance. The alloy has a
composition containing 10 to 40% by mass of Ni, 5 to 25% by mass of
Sn, 0.1 to 0.9% by mass of P, 0.3 to 6% by mass of calcium
fluoride, 0.3 to 6% by mass of molybdenum disulfide and the
remainder containing Cu and inevitable impurities, and has a
structure in which a phase of a composition containing
Cu.sub.(4-x-y)Ni.sub.xSn.sub.y (where x: 1.7 to 2.3, y: 0.2 to
1.3), a phase of a composition containing Cu.sub.(4-z)P.sub.z
(where z: 0.7 to 1.3), a calcium fluoride phase and a molybdenum
disulfide phase are dispersed in a matrix.
[0031] (16) A Cu--Ni--Sn copper-based sintered alloy having
excellent friction properties and wear resistance. The alloy has a
composition containing 10 to 40% by mass of Ni, 5 to 25% by mass of
Sn, 1 to 10% by mass of C, 0.3 to 6% by mass of calcium fluoride,
0.3 to 6% by mass of molybdenum disulfide and the remainder
containing Cu and inevitable impurities, and has a structure in
which a phase of a composition containing
Cu.sub.(4-x-y)Ni.sub.xSn.sub.y (where x: 1.7 to 2.3, y: 0.2 to
1.3), a graphite phase, a calcium fluoride phase and a molybdenum
disulfide phase are dispersed in a matrix.
[0032] (17) A Cu--Ni--Sn copper-based sintered alloy having
excellent friction properties and wear resistance. The alloy has a
composition containing 10 to 40% by mass of Ni, 5 to 25% by mass of
Sn, 0.1 to 0.9% by mass of P, 1 to 10% by mass of C, 0.3 to 6% by
mass of calcium fluoride, 0.3 to 6% by mass of molybdenum disulfide
and the remainder containing Cu and inevitable impurities, and has
a structure in which a phase of a composition containing
Cu.sub.(4-x-y)Ni.sub.xSn.sub.y (where x: 1.7 to 2.3, y: 0.2 to
1.3), a phase of a composition containing Cu.sub.(4-z)P.sub.z
(where z: 0.7 to 1.3), a graphite phase, a calcium fluoride phase
and a molybdenum disulfide phase are dispersed in a matrix.
[0033] For the range described above, calcium fluoride and
molybdenum disulfide are preferably in the range of 0.5 to 5% by
mass, respectively.
[0034] The Cu--Ni--Sn copper-based sintered alloy according to any
one of (1) to (17), exhibits excellent friction properties and wear
resistance. In addition, the alloy according to the invention
exhibits improved friction properties and wear resistance when it
is used for various electrical parts and machine parts, and
particularly, for oil-impregnated bearings. Particularly, when the
alloy according to the invention is used for the bearing of a shaft
having a high-rotation frequency, a bearing having a long lifetime
is effectively obtained.
BRIEF DESCRIPTION OF THE DRAWINGS
[0035] FIG. 1 is a pattern diagram showing a structure of a
Cu--Ni--Sn copper-based sintered alloy according to the invention,
which has excellent friction properties and wear resistance.
[0036] FIG. 2 is a pattern diagram showing a structure of the
Cu--Ni--Sn copper-based sintered alloy according to the invention,
which has excellent friction properties and wear resistance.
[0037] FIG. 3 is a pattern diagram showing a structure of the
Cu--Ni--Sn copper-based sintered alloy according to the invention,
which has excellent friction properties and wear resistance.
[0038] FIG. 4 is a pattern diagram showing a structure of the
Cu--Ni--Sn copper-based sintered alloy according to the invention,
which has excellent friction properties and wear resistance.
[0039] FIG. 5 is a pattern diagram showing a structure of the
Cu--Ni--Sn copper-based sintered alloy according to the invention,
which has excellent friction properties and wear resistance.
[0040] FIG. 6A is a plan view showing an example of the embodiment
of a bearing made of the Cu--Ni--Sn copper-based sintered alloy
according to the invention, which has excellent friction properties
and wear resistance.
[0041] FIG. 6B is a cross-sectional view showing an example of the
embodiment of the bearing made of the Cu--Ni--Sn copper-based
sintered alloy according to the invention, which has excellent
friction properties and wear resistance.
SUMMARY OF THE INVENTION
[0042] To produce the Cu--Ni--Sn copper-based sintered alloy
according to any one of the above (1) to (17), having excellent
friction properties and wear resistance, the following raw powders
are prepared:
[0043] a Cu--Ni alloy powder having a composition containing 5 to
45% by mass of Ni and the remainder containing Cu and inevitable
impurities;
[0044] a Cu--Ni--Sn alloy powder having a composition containing 25
to 60% by mass of Ni, 5 to 60% by mass of Sn and the remainder
containing Cu and inevitable impurities;
[0045] a Sn powder;
[0046] a Cu--P alloy powder having a composition containing 8% by
mass of P and the remainder containing Cu and inevitable
impurities;
[0047] a graphite powder;
[0048] a calcium fluoride powder; and
[0049] a molybdenum disulfide powder;
[0050] These powers are added and mixed to produce a mixed powder
having the composition according to any one of the above (1) to
(17). The resulting mixed powder is subjected to compacting to
obtain a compressed powder, and the compressed powder is sintered
at a temperature higher than a usual sintering temperature in the
range of 700 to 950.degree. C.
[0051] The obtained sintered material is gradually cooled at a
cooling rate of from 5 to 10.degree. C./min, slower than a known
cooling rate of 15.degree. C./min or faster.
[0052] A Cu--Ni--Sn copper-based sintered alloy exhibiting
excellent friction properties and wear resistance is obtained in
this manner. In the alloy, pores are dispersed and distributed in a
matrix at a porosity of 5 to 25%.
[0053] The above-mentioned sintering temperature is preferably in
the range of 900 to 1080.degree. C., and more preferably in the
range of 900 to 980.degree. C.
[0054] FIGS. 6A and 6B are a plan view and a cross-sectional view,
respectively, showing examples of the embodiment of a bearing made
of a Cu--Ni--Sn copper-based sintered alloy which has excellent
friction properties and wear resistance.
[0055] Next, the reasons the composition of the Cu--Ni--Sn
copper-based sintered alloy according to the invention, which
exhibits excellent friction properties and wear resistance, and x
and y for the phase of the composition containing
Cu.sub.(4-x-y)Ni.sub.xSn.sub.y (where x: 1.7 to 2.3, y: 0.2 to 1.3)
are limited to the above will be described.
[0056] (A) Reason for Limitation on Composition
[0057] (a) Ni
[0058] Ni is a component for improving strength, friction
properties and wear resistance under the high-temperature
environment. However, when the content of Ni is less than 10%, a
desired effect can not be obtained, and when the content of Ni is
greater than 40%, resistance between a shaft and a sliding surface
under the high-temperature environment increases, and thus the
level of wear increases quickly. Accordingly, the content of Ni
contained in the Cu--Ni--Sn copper-based sintered alloy according
to the invention is set in the range of 10 to 40%.
[0059] (b) Sn
[0060] Sn is a component for forming a solid solution as the matrix
with Cu and Ni to improve the strength and the wear resistance of a
bearing. However, when the content of Sn is less than 5%, a desired
strength-enhancing effect can not be obtained, and when the content
of Sn is greater than 25%, wear and tear corresponding material
such as a stainless steel shaft rapidly becomes greater, and the
wear of the stainless steel is accelerated. Accordingly, the
content of Sn is set in the range of 5 to 25%.
[0061] (c) P
[0062] P is a component for improving sinterability at the time of
sintering and for improving the strength of a matrix, that is, the
strength of a bearing. Accordingly, it is added as needed. However,
when the content of P is less than 0.1%, unpreferably, sufficient
strength can not be obtained, because sinterability is not
sufficiently exhibited. In addition, when the content of P is
greater than 0.9%, the strength of a sintered alloy is lowered,
because the strength of a grain boundary portion is lowered
quickly. Accordingly, the content of P is set in the range of 0.1
to 0.9%.
[0063] (d) C
[0064] C is a component existing as free graphite, the body of
which is dispersed and distributed in a matrix. In addition, C is a
component for improving the lubricating properties of a bearing and
the wear resistance of a bearing and a stainless steel shaft.
Accordingly, it is added as needed. However, when the content of C
is less than 1%, a ratio of dispersion and distribution of free
graphite is insufficient, and desired, excellent lubricating
properties can not be ensured, and when the content of C is greater
than 10%, the strength of a bearing is lowered quickly, and the
wear thereof increases quickly. Accordingly, the content of C is
set in the range of 1 to 10%.
[0065] (e) Calcium Fluoride
[0066] Calcium fluoride serves to significantly improve seizure
resistance, and thus it is added as needed. However, when the
content of calcium fluoride is less than 0.3%, a desired effect can
not be obtained, and when the content of calcium fluoride is
greater than 6%, strength, friction properties and wear resistance
are lowered. Accordingly, the content of calcium fluoride is set in
the range of 0.3 to 6%.
[0067] (f) Molybdenum Disulfide
[0068] Molybdenum disulfide serves to improve seizure resistance,
and thus it is added as needed. However, when the content of
molybdenum disulfide is less than 0.3%, a desired effect can not be
obtained, and when the content of molybdenum disulfide is greater
than 6%, strength, friction properties and wear resistance are
lowered. Accordingly, the content of molybdenum disulfide is set in
the range of 0.3 to 6%.
[0069] (B) Reason for Limitation on Phase of
Cu.sub.(4-x-y)Ni.sub.xSn.sub.y
[0070] x and y for the phase of Cu.sub.(4-x-y)Ni.sub.xSn.sub.y are
set in the range of 1.7 to 2.3 and in the range of 0.2 to 1.3,
respectively. A CuNi.sub.2Sn phase having a high hardness is
largely generated on a matrix by sintering at a temperature in the
range of 900 to 1080 degrees, which is higher than a normal
temperature range, and by gradually cooling at a speed lower than a
normal speed. However, a complete CuNi.sub.2Sn phase is hardly
generated, and a Cu.sub.(4-x-y)Ni.sub.xSn.sub.y phase in which x is
in the range of 1.7 to 2.3 and y is in the range of 0.2 to 1.3 is
generated. When x and y for a Cu.sub.(4-x-y)Ni.sub.xSn.sub.y phase
is in these ranges, friction properties and wear resistance of the
phase are improved.
First Example
[0071] The Cu--Ni--Sn copper-based sintered alloy according to the
invention, which exhibits friction properties and wear resistance,
will be described in detail with reference to the example. Powders
having the following characteristics were provided as raw
powders:
[0072] an atomized Cu--Ni powder having an average particle size of
150 .mu.m or less, and having a composition containing 15 to 42.5%
by mass of Ni and the remainder containing Cu and inevitable
impurities;
[0073] a Cu--Ni--Sn alloy powder having an average particle size of
150 .mu.m or less, and having a composition containing 25 to 60% by
mass of Ni, 5 to 60% by mass of Sn and the remainder containing Cu
and inevitable impurities;
[0074] an atomized Sn powder having an average particle size of 20
.mu.m;
[0075] a Cu--P alloy (Cu-8.4% P eutectic alloy) powder having an
average particle size of 150 .mu.m or less;
[0076] a graphite powder having an average particle size of 20
.mu.m;
[0077] a CaF.sub.2 powder having an average particle size of 60
.mu.m; and
[0078] a MoS.sub.2 powder having an average particle size of 150
.mu.m or less.
[0079] The raw powders added to obtain the final compositions
described in Tables 1 and 2, a stearic acid of 1% was added
thereto, and then the mixture was mixed in a V-shaped mixer for 20
minutes. Subsequently, the mixture was subjected to pressing to
obtain a compressed powder, and the compressed powder was sintered
at a predetermined temperature in the range of 900 to 1080.degree.
C. in an ammonia decomposed gas atmosphere. As a result,
ring-shaped test pieces 1 to 16 of the Cu--Ni--Sn copper-based
sintered alloy according to the invention, ring-shaped comparative
pieces 1 to 8 of a Cu--Ni--Sn copper-based sintered alloy, and
ring-shaped test pieces 1 to 3 of a known Cu--Ni--Sn copper-based
sintered alloy, which respectively had the compositions and the
porosities described in Tables 1 and 2, were prepared. These all
had the same size as follows: outside diameter 18 mm.times.inside
diameter 8 mm.times.height 8 mm.
[0080] A representative one of the obtained ring-shaped test pieces
1 to 16 of the Cu--Ni--Sn copper-based sintered alloy according to
the invention was observed by EPMA, and the observed structure is
shown in pattern diagrams 1 to 5. FIG. 1 is a pattern diagram
showing a structure of a Cu--Ni--Sn copper-based sintered alloy 1
according to the invention, FIG. 2 is a pattern diagram showing a
structure of the Cu--Ni--Sn copper-based sintered alloy 3 according
to the invention, FIG. 3 is a pattern diagram showing a structure
of the Cu--Ni--Sn copper-based sintered alloy 4 according to the
invention, FIG. 4 is a pattern diagram showing a structure of the
Cu--Ni--Sn copper-based sintered alloy 8 according to the
invention, and FIG. 5 is a pattern diagram showing a structure of
the Cu--Ni--Sn copper-based sintered alloy 16 according to the
invention.
[0081] The obtained ring-shaped test pieces 1 to 16 of the
Cu--Ni--Sn copper-based sintered alloy according to the invention,
ring-shaped comparative pieces 1 to 8 of a Cu--Ni--Sn copper-based
sintered alloy, and ring-shaped test pieces 1 to 3 of a known
Cu--Ni--Sn copper-based sintered alloy were dipped in synthetic
oil. Using the ring-shaped test pieces 1 to 16 of the Cu--Ni--Sn
copper-based sintered alloy according to the invention, ring-shaped
comparative pieces 1 to 8 of a Cu--Ni--Sn copper-based sintered
alloy, and ring-shaped test pieces 1 to 3 of a known Cu--Ni--Sn
copper-based sintered alloy, which had been dipped in the synthetic
oil, the tests described below were performed.
[0082] Crush Test:
[0083] The ring-shaped test pieces 1 to 16 of the Cu--Ni--Sn
copper-based sintered alloy according to the invention, ring-shaped
comparative pieces 1 to 8 of a Cu--Ni--Sn copper-based sintered
alloy, and ring-shaped test pieces 1 to 3 of a known Cu--Ni--Sn
copper-based sintered alloy, which had been dipped in the synthetic
oil, were heated to 120.degree. C., and a load was applied to the
heated ring-shaped test samples from the radial direction thereof.
The crush loads at the time that the ring-shaped test pieces were
crushed were measured, and the strength and toughness of each test
piece were evaluated as described in Tables 1 and 2.
[0084] Wear Resistance Test:
[0085] A shaft made of SUS304 and finished with 6S was inserted to
the ring-shaped test pieces 1 to 16 of the Cu--Ni--Sn copper-based
sintered alloy according to the invention, ring-shaped comparative
pieces 1 to 8 of a Cu--Ni--Sn copper-based sintered alloy, and
ring-shaped test pieces 1 to 3 of a known Cu--Ni--Sn copper-based
sintered alloy, which had been dipped in the synthetic oil. Then,
the ring-shaped test pieces were heated to 120.degree. C., while a
load of 0.2 MPa was applied from the outside of the ring-shaped
test pieces in the radial direction (the direction perpendicular to
the axis direction of the shaft) of the ring-shaped test pieces 1
to 16 of the Cu--Ni--Sn copper-based sintered alloy according to
the invention, ring-shaped comparative pieces 1 to 8 of a
Cu--Ni--Sn copper-based sintered alloy, and ring-shaped test pieces
1 to 3 of a known Cu--Ni--Sn copper-based sintered alloy.
Subsequently, the shaft was rotated at a rate of 50 n/min for 30
minutes. The maximum wear depth of the inside diameter of each test
piece was measured, and the strength, friction properties, and wear
resistance of each test piece were evaluated as described in Tables
1 and 2.
[0086] Seizure Resistance Test:
[0087] A shaft made of SUS304 and finished with 6S was inserted to
the ring-shaped test pieces 1 to 16 of the Cu--Ni--Sn copper-based
sintered alloy according to the invention, ring-shaped comparative
pieces 1 to 8 of a Cu--Ni--Sn copper-based sintered alloy, and
ring-shaped test pieces 1 to 3 of a known Cu--Ni--Sn copper-based
sintered alloy, which had been dipped in the synthetic oil. Then,
the ring-shaped test pieces 1 to 16 of the Cu--Ni--Sn copper-based
sintered alloy according to the invention, ring-shaped comparative
pieces 1 to 8 of a Cu--Ni--Sn copper-based sintered alloy, and
ring-shaped test pieces 1 to 3 of a known Cu--Ni--Sn copper-based
sintered alloy were maintained at 120.degree. C., and the shaft was
rotated at a rate of 50 n/min for 30 minutes, while a load was
applied in the radial direction (the direction perpendicular to the
axis direction of the shaft) of the ring-shaped test pieces.
Subsequently, the load was gradually increased, and the load at the
time that seizure was generated was measured. The seizure
resistance of each test piece was evaluated as described in Tables
1 and 2.
TABLE-US-00001 TABLE 1 Cu--Ni--Sn copper-
Cu.sub.(4-x-y)Ni.sub.xSn.sub.y Crush Maximum Seizure based sintered
Composition (% by mass) phase load wear depth load alloy Ni Sn P C
CaF.sub.2 MoS.sub.2 Cu x y Porosity (%) (MPa) (.mu.m) (MPa)
Examples 1 24.1 8.9 -- -- -- -- balance 1.9 1.1 11.4 422 3 4.2 of
the 2 24.3 10.5 0.3 -- -- -- balance 1.9 1.2 10.4 455 2 5.2
invention 3 25.0 11.1 -- 6.4 -- -- balance 1.9 1.1 11.3 391 1 6.4 4
20.0 9.1 0.4 7.2 -- -- balance 1.8 1.1 10.1 408 1 6.4 5 28.0 11.2
-- -- 3.1 -- balance 2.0 1.1 12.4 402 2 4.2 6 26.6 12.3 0.4 -- 4.5
-- balance 2.2 1.1 12.2 421 4 6.4 7 32.5 8.9 -- 5.6 1.1 -- balance
2.1 0.8 10.5 365 2 6.4 8 24.4 15.3 0.2 3.8 2.2 -- balance 2.1 1.0
10.8 381 3 5.8 9 24.1 18.2 -- -- -- 2.1 balance 2.1 1.2 11.3 411 1
6.1 10 23.2 13.2 0.2 -- -- 2.4 balance 2.1 1.1 10.5 420 1 5.2 11
25.3 14.4 -- 5.1 -- 2.5 balance 2.1 1.0 14.1 365 1 6.4 12 34.2 14.6
0.2 3.2 -- 2.2 balance 2.2 0.9 12.3 381 2 6.4 13 34.5 12.1 -- --
4.3 2.6 balance 2.2 0.8 12.2 392 3 4.9 14 32.0 13.1 0.3 -- 2.1 2.2
balance 2.1 0.7 13.6 404 1 5.2 15 33.5 16.2 -- 1.8 5.1 2.0 balance
2.1 0.7 13.2 374 2 5.6
TABLE-US-00002 TABLE 1 Cu--Ni--Sn copper-
Cu.sub.(4-x-y)Ni.sub.xSn.sub.y Crush Maximum Seizure based sintered
Composition (% by mass) phase load wear depth load alloy Ni Sn P C
CaF.sub.2 MoS.sub.2 Cu X y Porosity (%) (MPa) (.mu.m) (MPa) 16 33.3
16.1 0.2 1.6 3.8 2.9 balance 1.9 1.0 12.0 380 2 6.5 comparative 1
8.3 11.2 -- -- -- -- balance 1.6* 1.2 11.2 298 82 1.5 examples 2
48.3 10.0 -- -- -- -- balance 2.4* 0.8 10.3 320 58 2.1 3 25.0 4.2
-- -- -- -- balance 2.1 0.1* 11.6 310 63 1.5 4 24.2 28.2 -- -- --
-- balance 1.8 1.4* 13.1 365 71 2.6 5 8.1 10.5 0.2 -- -- -- balance
1.6* 1.1 14.2 382 82 1.1 6 49.1 10.3 0.2 -- -- -- balance 2.4* 1.1
10.8 371 105 1.4 7 24.0 4.1 -- 3.1 -- -- balance 2.0 0.1* 12.1 280
65 2.8 8 24.6 28.4 -- 3.3 -- -- balance 2.2 1.4* 12.5 315 89 3.2
known 1 24.1 8.1 0.2 -- -- -- balance -- 11.5 325 120 1.1 examples
2 24.3 7.8 -- 3.1 -- -- balance -- 11.3 354 63 1.4 3 23.8 7.8 -- --
-- 2 balance -- 11.2 341 95 1.3 *mark shows the value that is out
of the conditions of the invention.
[0088] The Cu--Ni--Sn copper-based sintered alloy according to any
one of the above (1) to (17), exhibits excellent friction
properties and wear resistance. In addition, the alloy according to
the invention exhibits improved friction properties and wear
resistance when it is used for various electrical parts and
mechanical parts, and particularly, for an oil-impregnated bearing.
Particularly, when the alloy according to the invention is used for
the bearing of a shaft having a high rotation speed, a bearing
having a long lifetime is effectively obtained.
* * * * *