U.S. patent application number 12/278996 was filed with the patent office on 2010-07-08 for aluminum-bronze alloy as raw materials for semi solid metal casting.
This patent application is currently assigned to Mitsubishi Shindoh Co., Ltd. Invention is credited to Keiichiro Oishi.
Application Number | 20100172791 12/278996 |
Document ID | / |
Family ID | 38371480 |
Filed Date | 2010-07-08 |
United States Patent
Application |
20100172791 |
Kind Code |
A1 |
Oishi; Keiichiro |
July 8, 2010 |
ALUMINUM-BRONZE ALLOY AS RAW MATERIALS FOR SEMI SOLID METAL
CASTING
Abstract
An aluminum-bronze alloy as raw materials for Semi Solid Metal
casting has a component composition containing Al of 5 to 10 mass
%, Zr of 0.0005 to 0.04 mass %, and P of 0.01 to 0.25 mass %, and a
balance of Cu and inevitable impurities, further containing Si of
0.5 to 3 mass % as needed, and further containing one or more kinds
of Pb of 0.005 to 0.45 mass %, Bi of 0.005 to 0.45 mass %, Se of
0.03 to 0.45 mass %, and Te of 0.01 to 0.45 mass % as needed.
Inventors: |
Oishi; Keiichiro; (Osaka,
JP) |
Correspondence
Address: |
Leason Ellis LLP
81 Main Street, Suite 503
White Plains
NY
10601
US
|
Assignee: |
Mitsubishi Shindoh Co., Ltd
Tokyo
JP
|
Family ID: |
38371480 |
Appl. No.: |
12/278996 |
Filed: |
February 13, 2007 |
PCT Filed: |
February 13, 2007 |
PCT NO: |
PCT/JP2007/052487 |
371 Date: |
August 11, 2008 |
Current U.S.
Class: |
420/489 |
Current CPC
Class: |
C22C 9/01 20130101; B22D
17/007 20130101; C22C 1/005 20130101 |
Class at
Publication: |
420/489 |
International
Class: |
C22C 9/01 20060101
C22C009/01 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 13, 2006 |
JP |
2006-035004 |
Claims
1. An aluminum-bronze alloy as raw materials for Semi Solid Metal
casting, having a component composition containing Al of 5 to 10
mass %, Zr of 0.0005 to 0.04 mass %, P of 0.01 to 0.25 mass %, and
a balance of Cu and inevitable impurities.
2. An aluminum-bronze alloy as raw materials for Semi Solid Metal
casting, having a component composition containing Al of 5 to 10
mass %, Zr of 0.0005 to 0.04 mass %, P of 0.01 to 0.25 mass %, Si
of 0.5 to 3 mass %, and a balance of Cu and inevitable
impurities.
3. An aluminum-bronze alloy as raw materials for Semi Solid Metal
casting according to claim 1, wherein the component composition
further contains one or more kinds of Pb of 0.005 to 0.45 mass %,
Bi of 0.005 to 0.45 mass %, Se of 0.03 to 0.45 mass %, and Te of
0.01 to 0.45 mass %.
4. The aluminum-bronze alloy as raw materials for Semi Solid Metal
casting according to claim 2, wherein the component composition
further contains one or more kinds of Pb of 0.005 to 0.45 mass %,
Bi of 0.005 to 0.45 mass %, Se of 0.03 to 0.45 mass %, and Te of
0.01 to 0.45 mass %.
Description
TECHNICAL FIELD
[0001] The present invention relates to an aluminum-bronze alloy as
raw materials for Semi Solid Metal casting that can be used to
produce an aluminum-bronze alloy cast having fine grains by Semi
Solid Metal casting (semi-solid alloy casting) without agitating a
molten metal.
[0002] Priority is claimed on Japanese Patent Application No.
2006-035004, filed Feb. 13, 2006, the content of which is
incorporated herein by reference.
BACKGROUND ART
[0003] A Cu--Al copper alloy containing copper and aluminum as
major components is known as an aluminum-bronze alloy. The
aluminum-bronze alloy is a copper alloy with improved mechanical
properties, corrosion resistance, wear resistance, fatigue
resistance, and thermal resistance by adding Al of 10.5 mass % or
less to Cu. It is generally known that this aluminum-bronze alloy
is poor in casting property. However, since the aluminum-bronze
alloy is excellent in mechanical properties, corrosion resistance,
wear resistance, fatigue resistance, and thermal resistance, the
aluminum-bronze alloy is used as a material of ship screws, screw
shafts, pumps, chemical instruments, bearings, gears and the
like.
[0004] It is generally known that the aluminum-bronze alloy is poor
in casting property. The main reason results from a component
composition thereof. Another reason for the low flowability of the
molten metal is that dendritic a primary crystals are crystallized
in the molten aluminum-bronze alloy. As a method of improving the
deterioration in casting property due to the crystallization of the
dendritic a primary crystals, a Semi Solid Metal casting method is
known in which when a slurry-phase semi-solid aluminum-bronze alloy
is produced by strongly agitating the molten aluminum-bronze alloy
in a temperature range between the liquidus temperature and the
solidus temperature and the semi-solid aluminum-bronze alloy is
cast, dendrite generated in the solid-liquid mixture slurry is
segmentalized by the agitation and the .alpha. primary crystal
solid in the solid-liquid mixture slurry is formed in a sphere,
thereby maintaining the flowability at a high solid phase ratio.
Accordingly, it is possible to improve the casting property and to
produce an aluminum-bronze alloy cast having a structure including
fine grains and granular crystals (see Non-patent Document 1).
[0005] [Non-patent Document 1] "Fifth Revised Edition of Metal
Manual," edited by THE JAPAN INSTITUTE OF METALS, MARUZEN Co., Ltd.
(published on Apr. 20, 1992), P1041 to P1042
DISCLOSURE OF THE INVENTION
Problems to be Solved by the Invention
[0006] However, in executing the Semi Solid Metal casting method in
which the molten metal is agitated, since it is necessary to
perform the agitation under the control of a molten metal
temperature, an apparatus needs to be increased in size.
Accordingly, superfluous gas may be introduced into the molten
metal under some conditions. The molten metal temperature needs to
be lowered in consideration of wear damage. However, the generation
of the dendrite structure cannot be completely suppressed even when
the known aluminum-bronze alloy is agitated in a semi-solid state.
Accordingly, the flowability of the molten metal is markedly
deteriorated, thereby finally causing casting failure.
[0007] The invention is contrived in view of the above-mentioned
problems. An object of the invention is to provide aluminum-bronze
alloy as raw materials for Semi Solid Metal casting that can
produce aluminum-bronze alloy cast having an excellent casting
property and fine grains by the use of a Semi Solid Metal casting
method without using a member for agitating the molten metal.
Means for Solving the Problems
[0008] Therefore, the inventors studied in order to enhance the
flowability of the semi-solid aluminum-bronze alloy without using
an agitating member for segmentalizing and granulating dendrite in
a liquid phase and to produce an aluminum-bronze alloy cast having
fine grains without casting failure even when the semi-solid
aluminum-bronze alloy is cast at a low temperature. As a result,
the following observations (A) to (D) were found out.
[0009] (A) A semi-solid aluminum-bronze alloy obtained by using
aluminum-bronze alloy, which was obtained by adding Zr of 0.0005 to
0.04 mass % and P of 0.01 to 0.25 mass % to an aluminum-bronze
alloy containing Al of 5 to 10 mass %, as a raw alloy, completely
melting the aluminum-bronze alloy into a liquid phase, and cooling
the molten aluminum-bronze alloy, and a semi-solid aluminum-bronze
alloy obtained by re-melting the ingot and the like are both
excellent in flowability. Accordingly, it was found that it is
possible to produce an aluminum-bronze alloy cast having fine
grains by casting the semi-solid aluminum-bronze alloy and that it
is not necessary to perform an agitation process in a semi-solid
alloy, unlike in the case of known examples.
[0010] (B) A semi-solid aluminum-bronze alloy obtained by using an
aluminum-bronze alloy, which is obtained by adding Si of 0.5 to 3
mass % to the aluminum-bronze alloy according to (A) containing Zr
of 0.0005 to 0.04 mass % and P of 0.01 to 0.25 mass %, as a raw
alloy, completely melting the aluminum-bronze alloy into a liquid
phase, and cooling the molten aluminum-bronze alloy, and a
semi-solid aluminum-bronze alloy obtained by re-melting the ingot
and the like are both excellent in flowability. Accordingly, it was
found that it is possible to produce an aluminum-bronze alloy cast
having fine grains by casting the semi-solid aluminum-bronze alloy
and that it is not necessary to perform an agitation process in a
semi-solid alloy unlike in the case of known examples.
[0011] (C) It was found that an aluminum-bronze alloy having a
component composition further containing one or more of Pb of 0.005
to 0.45 mass %, Bi of 0.005 to 0.45 mass %, Se of 0.03 to 0.45 mass
%, and Te of 0.01 to 0.45 mass % in addition to the aluminum-bronze
alloy according to (A) or (B) exhibits the same advantages.
[0012] (D) It was found that the reason for the excellent
flowability in the semi-solid alloy state of the aluminum-bronze
alloy according to (A), (B), or (C) is that fine and granular a
primary crystals are generated instead of dendrite in the course of
solidification.
[0013] The invention provides the following based on the
above-mentioned study results:
[0014] (1) An aluminum-bronze alloy as raw materials for Semi Solid
Metal casting, having a component composition containing Al of 5 to
10 mass %, Zr of 0.0005 to 0.04 mass %, P of 0.01 to 0.25 mass %
and a balance of Cu and inevitable impurities.
[0015] (2) An aluminum-bronze alloy as raw materials for Semi Solid
Metal casting, having a component composition containing Al of 5 to
10 mass %, Zr of 0.0005 to 0.04 mass %, P of 0.01 to 0.25 mass %,
Si of 0.5 to 3 mass %, and a balance of Cu and inevitable
impurities.
[0016] (3) The component composition of the aluminum-bronze alloy
as raw materials for Semi Solid Metal casting according to (1) or
(2) may further contain one or more kinds of Pb of 0.005 to 0.45
mass %, Bi of 0.005 to 0.45 mass %, Se of 0.03 to 0.45 mass %, and
Te of 0.01 to 0.45 mass %.
ADVANTAGES OF THE INVENTION
[0017] When the aluminum-bronze alloy as raw materials for Semi
Solid Metal casting according to the invention is melted to produce
a semi-solid aluminum-bronze alloy in a solid-liquid mixture slurry
and the semi-solid aluminum-bronze alloy is cast using a
conventional method, a fine .alpha. primary phase is generated or
an .alpha. solid phase coexists in the liquid phase of the
semi-solid aluminum-bronze alloy. Accordingly, even when an
agitating apparatus is not used, it is possible to cast the
semi-solid aluminum-bronze alloy without damaging the flowability
of the semi-solid aluminum-bronze alloy. In addition, it is an
advantage that the crystal grains of the aluminum-bronze alloy cast
obtained by casting the semi-solid aluminum-bronze alloy are
further reduced in size, thereby further enhancing the mechanical
strength.
BEST MODE FOR CARRYING OUT THE INVENTION
[0018] Hereinafter, the invention will be described in detail.
[0019] An aluminum-bronze alloy as raw materials for Semi Solid
Metal casting according to the invention has a component
composition containing Al of 5 to 10 mass %, Zr of 0.0005 to 0.04
mass %, P of 0.01 to 0.25 mass %, and a balance of Cu and
inevitable impurities.
[0020] The aluminum-bronze alloy as raw materials for Semi Solid
Metal casting according to the invention may have a component
composition containing Al of 5 to 10 mass %, Zr of 0.0005 to 0.04
mass %, P of 0.01 to 0.25 mass %, Si of 0.5 to 3 mass %, and a
balance of Cu and inevitable impurities.
[0021] The aluminum-bronze alloy as raw materials for Semi. Solid
Metal casting according to the invention may have a component
composition containing Al of 5 to 10 mass %, Zr of 0.0005 to 0.04
mass %, P of 0.01 to 0.25 mass %, Si of 0.5 to 3 mass %, and a
balance of Cu and inevitable impurities and further containing one
or more kinds of Pb of 0.005 to 0.45 mass %, Bi of 0.005 to 0.45
mass %, Se of 0.03 to 0.45 mass %, and Te of 0.01 to 0.45 mass
%.
[0022] An ingot of the aluminum-bronze alloy as raw materials for
Semi Solid Metal casting according to the invention, the component
composition of which is adjusted, is produced and stored in
advance, a semi-solid aluminum-bronze alloy is produced by
re-melting a necessary amount of the aluminum-bronze alloy as raw
materials, and a semi-solid aluminum-bronze alloy cast having fine
grains can be manufactured by casting the semi-solid
aluminum-bronze alloy.
[0023] The reasons for defining the component composition of the
aluminum-bronze alloy as raw materials for Semi Solid Metal casting
according to the invention as described above will be
described.
[0024] Al:
[0025] Al has a function of improving mechanical properties,
corrosion resistance, wear resistance, fatigue resistance, and
thermal resistance by means of the addition thereof to Cu, and a
function of preventing the oxidation of Zr by means of its
deoxidizing effect. When the content thereof is less than 5 mass %,
it is not preferable because a sufficient effect cannot be
obtained. On the other hand, when the content thereof is greater
than 10 mass %, it is not preferable because the casting property
is deteriorated and the obtained cast is hard and brittle, thus
reducing the mechanical strength. Accordingly, the content of Al
contained in the aluminum-bronze alloy as raw materials for Semi
Solid Metal casting according to the invention is defined in the
range of 5 mass % to 10 mass %.
[0026] Zr:
[0027] With its coexistence with P, Zr has a function of promoting
the generation of fine and granular .alpha. primary crystals in a
semi-solid state, improving the flowability of the semi-solid
aluminum-bronze alloy, and reducing the size of the crystal grains
of the aluminum-bronze alloy cast. When the content thereof is less
than 0.0005 mass %, it is not preferable because the reduction in
size of the crystal grains is not sufficient. On the other hand,
when the content is greater than 0.04 mass %, it is not preferable
because the crystal grains of the cast increase in size.
Accordingly, the content of Zr contained in the aluminum-bronze
alloy as raw materials for Semi Solid Metal casting according to
the invention is defined in the range of 0.0005 mass % to 0.04 mass
%.
[0028] P:
[0029] With the coexistence of Zr, P has a function of promoting
the generation of fine and granular a primary crystals in a
semi-solid state, improving the flowability of the semi-solid
aluminum-bronze alloy, and reducing the size of the crystal grains
of the aluminum-bronze alloy cast. When the content thereof is less
than 0.01 mass %, it is not preferable because the reduction in
size of the crystal grains is not sufficient. On the other hand,
when the content is greater than 0.25 mass %, it is not preferable
because intermetallic compounds with a low melting point are
generated, making it brittle. Accordingly, the content of P
contained in the aluminum-bronze alloy as raw materials for Semi
Solid Metal casting according to the invention is defined in the
range of 0.01 mass % to 0.25 mass %.
[0030] Si:
[0031] Si has a function of further improving the flowability of
the semi-solid aluminum-bronze alloy, lowering the melting point,
and enhancing corrosion resistance, strength, and machinability and
thus is added as needed. When the content thereof is less than 0.5
mass %, it is not preferable because a desired effect cannot be
obtained. On the other hand, when the content is greater than 3
mass %, it is not preferable because the flowability of the cast
decreases and is brittle. Accordingly, the content of Si contained
in the aluminum-bronze alloy as raw materials for Semi Solid Metal
casting according to the invention is defined in the range of 0.5
mass % to 3 mass %.
[0032] Other Components:
[0033] The aluminum-bronze alloy as raw materials for Semi Solid
Metal casting according to the invention may further contain one or
more kinds of Pb, Bi, Se, and Te as needed. When the components are
contained in the aluminum-bronze alloy, it is preferable that the
content of Pb be in the range of 0.005 mass % to 0.45 mass %, the
content of Bi be in the range of 0.005 mass % to 0.45 mass %, the
content of Se be in the range of 0.03 mass % to 0.45 mass %, and
the content of Te be in the range of 0.01 mass % to 0.45 mass
%.
[0034] By making the aluminum-bronze alloy as raw materials for
Semi Solid Metal casting according to the invention have the
above-mentioned component composition, when the aluminum-bronze
alloy as raw materials for Semi Solid Metal casting is melted to
produce a semi-solid aluminum-bronze alloy in a solid-liquid
mixture slurry and the semi-solid aluminum-bronze alloy is cast
using a conventional method, a fine and granular a primary phase is
generated or an .alpha. solid phase coexists in the liquid phase of
the semi-solid aluminum-bronze alloy. Accordingly, even when an
agitating apparatus is not used, it is possible to cast the
semi-solid aluminum-bronze alloy without damaging the flowability
of the semi-solid aluminum-bronze alloy. In addition, it is an
advantage that the crystal grains of the aluminum-bronze alloy cast
obtained by casting the semi-solid aluminum-bronze alloy are
further reduced in size, thereby further enhancing the mechanical
strength.
EMBODIMENTS
Embodiment 1
[0035] By preparing conventional cathode copper as a raw material,
feeding the cathode copper into an electrical furnace, melting the
cathode copper in an atmosphere of Ar gas, adding Al and P thereto
when the temperature of the molten copper is 1200.degree. C.,
adding Si, Pb, Bi, Se, Te, and the like thereto as needed, and
finally adding Zr thereto, a molten aluminum-bronze alloy was
produced. By casting the molten aluminum-bronze alloy, ingots of
aluminum-bronze alloys as raw materials for Semi Solid Metal
casting (hereinafter, referred to as aluminum-bronze alloys as raw
materials according to examples of the invention) according to
Examples 1 to 45 of the invention and aluminum-bronze alloys as raw
materials for Semi Solid Metal casting (hereinafter, referred to as
aluminum-bronze alloys as raw materials according to comparative
examples) according to Comparative Examples 1 to 6, which have the
component compositions shown in Tables 1 to 4, were produced.
[0036] By melting an aluminum-bronze alloy, which contains Al of 9
mass % and a balance of Cu and inevitable impurities and is
available on the market, in an atmosphere of Ar gas, a molten
aluminum-bronze alloy of a temperature of 1200.degree. C. was
produced. By casting the molten aluminum-bronze alloy, an ingot of
a conventional aluminum-bronze alloy as raw materials for Semi
Solid Metal casting (hereinafter, referred to as a conventional
aluminum-bronze alloy as raw materials) having the component
composition shown in Table 4 was produced.
[0037] By cutting out parts of the ingots of the aluminum-bronze
alloys as raw materials according to Examples 1 to 45 of the
invention, the aluminum-bronze alloys as raw materials according to
Comparative Examples 1 to 6, and the conventional aluminum-bronze
alloy as raw materials and heating the cut-out ingots at a
predetermined temperature between the solidus temperature and the
liquidus temperature to re-melt the ingots, semi-solid
aluminum-bronze alloys were produced. Quenched samples were
produced by rapidly quenching the semi-solid aluminum-bronze
alloys. By observing the structures of the quenched samples with an
optical microscope, the shapes of the .alpha. solid phase
coexisting with the liquid phase in the semi-solid aluminum-bronze
alloy were estimated and the average grain sizes thereof were
measured. The results are shown in Tables 1 to 4.
[0038] The average grain sizes of the .alpha. solid phase were
measured by etching the cutting surfaces of the quenched samples
with nitric acid and then observing the cutting surfaces with an
optical microscope.
TABLE-US-00001 TABLE 1 .alpha. solid phase in quenched sample
Aluminum-bronze Average alloy as raw Component composition (mass %)
grain size materials Al Zr P Si Pb Bi Se Te Cu shape (.mu.m)
Examples 1 5 0.0008 0.08 -- -- -- -- -- balance granular 200 of the
2 6 0.0015 0.01 -- -- -- -- -- balance granular 200 Present 3 7
0.006 0.07 -- -- -- -- -- balance granular 60 Invention 4 8 0.0094
0.05 -- -- -- -- -- balance granular 40 5 9 0.015 0.09 -- -- -- --
-- balance granular 60 6 10 0.018 0.11 -- -- -- -- -- balance
granular 120 7 8 0.0008 0.11 0.5 -- -- -- -- balance granular 100 8
9 0.0015 0.16 1 -- -- -- -- balance granular 90 9 7 0.006 0.13 3 --
-- -- -- balance granular 80 10 5 0.0008 0.08 -- 0.43 -- -- --
balance granular 200 11 8 0.0015 0.01 -- 0.35 -- -- -- balance
granular 150 12 10 0.006 0.07 -- 0.23 -- -- -- balance granular 100
13 7 0.018 0.11 -- 0.01 0.12 -- -- balance granular 40 14 6 0.028
0.13 -- -- 0.43 -- -- balance granular 100 15 7 0.039 0.19 -- --
0.35 -- -- balance granular 150
TABLE-US-00002 TABLE 2 .alpha. solid phase in quenched sample
Aluminum-bronze Average alloy as raw Component composition (mass %)
grain size materials Al Zr P Si Pb Bi Se Te Cu shape (.mu.m)
Examples 16 9 0.003 0.21 -- -- 0.23 -- -- balance granular 120 of
the 17 8 0.0015 0.16 -- -- 0.01 0.05 -- balance granular 100
Present 18 10 0.006 0.13 -- -- 0.005 0.06 0.01 balance granular 120
Invention 19 5 0.0008 0.08 -- -- -- 0.11 -- balance granular 200 20
8 0.0015 0.01 -- 0.1 -- 0.06 -- balance granular 200 21 10 0.006
0.07 -- -- -- 0.21 -- balance granular 150 22 7 0.018 0.11 -- -- --
0.35 -- balance granular 40 23 6 0.028 0.13 -- 0.005 0.005 0.03
0.01 balance granular 100 24 7 0.039 0.19 -- -- 0.005 -- 0.11
balance granular 150 25 9 0.003 0.21 -- 0.005 -- -- 0.05 balance
granular 120 26 8 0.0015 0.16 -- -- -- -- 0.45 balance granular 100
27 10 0.006 0.13 -- -- -- -- 0.35 balance granular 150 28 5 0.0008
0.08 3 0.43 -- -- -- balance granular 100 29 8 0.0015 0.01 1 0.35
-- -- -- balance granular 200 30 10 0.006 0.07 0.5 0.23 -- -- --
balance granular 150
TABLE-US-00003 TABLE 3 .alpha. solid phase in quenched sample
Aluminum-bronze Average alloy as raw Component composition (mass %)
grain size materials Al Zr P Si Pb Bi Se Te Cu shape (.mu.m)
Examples 31 7 0.018 0.11 3 0.01 -- -- 0.01 balance granular 35 of
the 32 6 0.028 0.13 5 -- 0.43 -- -- balance granular 45 Present 33
7 0.039 0.19 2 -- 0.35 -- -- balance granular 150 Invention 34 9
0.003 0.21 3 -- 0.23 -- -- balance granular 100 35 8 0.0015 0.16 2
-- 0.01 -- -- balance granular 100 36 10 0.006 0.13 3 -- 0.005 --
-- balance granular 150 37 5 0.0008 0.08 2 -- -- 0.11 -- balance
granular 150 38 8 0.0015 0.01 3 0.009 0.005 0.06 -- balance
granular 200 39 10 0.006 0.07 4 -- -- 0.21 -- balance granular 150
40 7 0.018 0.11 3 -- -- 0.35 -- balance granular 35 41 6 0.028 0.13
5 0.005 0.005 0.03 0.01 balance granular 45 42 7 0.039 0.19 2 -- --
-- 0.11 balance granular 120 43 9 0.003 0.21 3 0.005 -- 0.03 0.05
balance granular 100 44 8 0.0015 0.16 2 -- -- -- 0.45 balance
granular 100 45 10 0.006 0.13 3 -- -- -- 0.35 balance granular
150
TABLE-US-00004 TABLE 4 .alpha. solid phase in quenched sample
Aluminum-bronze Average alloy as raw Component composition (mass %)
grain size materials Al Zr P Si Pb Bi Se Te Cu shape (.mu.m)
Comparative 1 4* 0.015 0.05 -- -- -- -- -- balance granular 400
Examples 2 11* 0.015 0.05 -- -- -- -- -- balance dendrite-phase --
3 7 0.0003* 0.05 -- -- -- -- -- balance dendrite-phase -- 4 7
0.042* 0.04 -- -- -- -- -- balance granular 400 5 7 0.009 0.008* --
-- -- -- -- balance dendrite-phase -- 6 7 0.005 0.26* -- -- -- --
-- balance dendrite-phase -- Conventional 9 -- -- -- -- -- -- --
balance dendrite-phase -- Example *Mark represents a value
departing from the invention
[0039] It is estimated from the results shown in Tables 1 to 4 that
the fine granular .alpha. solid phase coexists with the liquid
phase in the semi-solid state of the aluminum-bronze alloys as raw
materials according to Examples 1 to 45 of the invention, since the
.alpha. solid phases of the quenched samples were all fined
granular. On the other hand, it is estimated that dendrite was
generated in the semi-solid state of the conventional
aluminum-bronze alloy as raw materials, since the .alpha. solid
phase of the quenched sample was all in a dendrite phase.
[0040] Accordingly, it can be seen that the semi-solid
aluminum-bronze alloys produced from the aluminum-bronze alloys as
raw materials according to Examples 1 to 45 of the invention were
better in terms of fluidity than the semi-solid aluminum-bronze
alloy produced from the conventional aluminum-bronze alloy as raw
materials and that a fine granular .alpha. solid phase was
generated in the liquid phase of the semi-solid aluminum-bronze
alloy obtained by melting the aluminum-bronze alloys as raw
materials according to Examples 1 to 45 of the invention, thereby
obtaining a cast having fine grains even when the semi-solid
aluminum-bronze alloy was cast without agitation. It can be also
seen that the aluminum-bronze alloys as raw materials according to
Comparative Examples 1 to 6 containing Al, Zr, and P that depart
from the condition of the invention (the range of component
composition of the invention) were not preferable since dendrite
was generated, a reduction in size of the crystal grains was
insufficient in the semi-solid state thereof, or the alloys were
brittle.
Embodiment 2
[0041] By cutting out parts of the ingots of the aluminum-bronze
alloys as raw materials according to Examples 1 to 45 of the
invention, produced in Embodiment 1, the aluminum-bronze alloys as
raw materials according to Comparative Examples 1 to 6, and the
conventional aluminum-bronze alloy as raw materials and completely
melting the cut-out ingots, molten aluminum-bronze alloys in a
liquid phase were produced. Semi-solid aluminum-bronze alloys
maintained at a predetermined temperature between the solidus
temperature and the liquidus temperature were produced by cooling
the molten aluminum-bronze alloy thereafter. Quenched samples were
produced by rapidly quenching the semi-solid aluminum-bronze
alloys. By observing the structures of the quenched samples with an
optical microscope, the shapes of the .alpha. solid crystals
generated in semi-solid aluminum-bronze alloys were estimated and
the average grain sizes thereof were measured. The results were the
same as in Embodiment 1.
[0042] While exemplary embodiments of the invention have been
described, the invention is not limited to the embodiments. The
elements of the embodiments may be added, omitted, replaced, or
modified without departing from the gist of the invention. The
invention is not limited to the above description, but is defined
only by the appended claims.
INDUSTRIAL APPLICABILITY
[0043] According to the aluminum-bronze alloy as raw materials for
Semi Solid Metal casting of the invention, it is possible to
produce an aluminum-bronze alloy cast having fine grains without
casting failure occurring even when the semi-solid aluminum-bronze
alloy is cast at a low temperature, by improving the flowability of
the semi-solid aluminum-bronze alloy without using a molten metal
agitating instrument.
* * * * *