Information
-
Patent Grant
-
6676899
-
Patent Number
6,676,899
-
Date Filed
Tuesday, November 12, 200221 years ago
-
Date Issued
Tuesday, January 13, 200420 years ago
-
Inventors
-
Original Assignees
-
Examiners
- Wyszomierski; George
- Morillo; Janelle Combs
Agents
-
CPC
-
US Classifications
Field of Search
US
- 420 532
- 420 543
- 420 544
- 420 533
- 420 534
- 420 535
- 148 439
- 148 440
-
International Classifications
-
Abstract
A chemical composition of alloys, in particular naturally hard semifinished-material alloys, which are intended to be used in this form as material for semifinished materials. A naturally hard aluminum alloy for semifinished materials which, in addition to magnesium, titanium, beryllium, zirconium, scandium, and cerium, is also made of manganese, copper, zinc, and an element group containing iron and silicon, the ratio of iron to silicon being in the range of 1 to 5.
Description
FIELD OF THE INVENTION
The present invention relates to a composition of alloys, such as naturally hard semifinished-material alloys, which are intended to be used in this form as material for structures.
BACKGROUND INFORMATION
Naturally hard aluminum alloys are used in metallurgy as semifinished materials for structures (see for example GOST standard 4784-74), but primarily in the form of AMg6 alloy, which contains the following (in percent by weight):
|
magnesium
5.8-6.8
|
manganese
0.5-0.8
|
titanium
0.02-0.1
|
beryllium
0.0002-0.005
|
aluminum
balance
|
|
This alloy, however, does not have adequate physical properties, in particular a low 0.2% yield strength in the case of cold-formed and hot-formed semifinished materials.
A naturally hard aluminum alloy, which is used as a semifinished material for structures (see Russian Patent No. 2085607, IPC class C22 C 21/06), provides the following chemical composition (% by weight):
|
magnesium
3.9-4.9
|
titanium
0.01-0.1
|
beryllium
0.0001-0.005
|
zirconium
0.05-0.15
|
scandium
0.20-0.50
|
cerium
0.001-0.004
|
aluminum
balance
|
|
This alloy does not have sufficient static and dynamic strength, while having high processibility during the manufacturing process, high corrosion resistance, good weldability, and a high readiness for operation under low-temperature conditions.
SUMMARY
The present invention is a new, naturally hard aluminum alloy for semifinished materials which, in addition to magnesium, titanium, beryllium, zirconium, scandium, and cerium, is also made of manganese, copper, zinc, and an element group containing iron and silicon, in the following composition of the components (weight %), the ratio of iron to silicon being in the range of 1 to 5:
|
magnesium
5.0-5.6
|
titanium
0.01-0.05
|
beryllium
0.0001-0.005
|
zirconium
0.05-0.15
|
scandium
0.18-0.30
|
cerium
0.001-0.004
|
manganese
0.05-0.18
|
copper
0.05-0.15
|
zinc
0.05-0.15
|
element group including
0.04-0.24
|
iron and silicon
|
aluminum
balance
|
|
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1
is a table of compositions of example embodiments of the present invention.
FIG. 2
is a table of properties of compositions of example embodiments of the present invention.
DETAILED DESCRIPTION
The alloy of the present invention is distinguished from other alloys by an addition of manganese, copper, zinc, and an element group containing iron and silicon, the components having the following proportions in weight percent, and with the ratio of iron to silicon between 1 and 5:
|
magnesium
5.0-5.6
|
titanium
0.01-0.05
|
beryllium
0.0001-0.005
|
zirconium
0.05-0.15
|
scandiumt
0.18-0.30
|
cerium
0.001-0.004
|
manganese
0.05-0.18
|
copper
0.05-0.15
|
zinc
0.05-0.15
|
element group including
0.04-0.24
|
iron and silicon
|
aluminum
balance
|
|
This alloy provides an improvement of the static and dynamic physical properties of the alloy. This results in the improvement of the service life, operational reliability, and weight value of the structures subjected to static and dynamic loads improve, in particular those of the structures of various aircraft and spacecraft, including craft that burn cryogenic fuel.
Due to the proportions of the present invention between the chemical levels and the chemical constituents, the alloy has a ductile matrix, which comprises a solid solution of dissolved magnesium, maganese copper, and zinc in aluminum.
The capability of the alloy for operation under cyclical dynamic loads is due to the high ductility of the matrix. Secondary precipitation of finely distributed intermetallic particles, which contain aluminum, scandium, zirconium, titanium, and other transition metals occurring in the alloy, provides for both the high static strength of the alloy and a high resistance to crack propagation during fatigue testing. The setpoint value of the ratio of iron to silicon optimizes the morphology of the primary intermetallic compounds, which result from the solidification, are principally made of aluminum, iron, and silicon, and provide for an improvement in the static strength of the alloy, while the dynamic strength and plasticity are maintained.
EXAMPLE
Using A85 aluminum, MG90 magnesium, copper MO, zinc TsO, binary key alloys such as aluminum-titanium, aluminum-beryllium, aluminum-zirconium, aluminum-scandium, aluminum-cerium, aluminum-manganese, aluminum-iron, and silumin as an additive, a melt was prepared in an electric oven, on which 165×550 mm flat ingots of the alloy according to the present invention were cast with the aid of semicontinuous casting techniques (Table 1); the ingots having a minimum (composition 1), optimum (composition 2), and maximum (composition 3) proportion of constituents, including proportions of the constituents going beyond the present limitations (compositions 4 and 5), as well as the conventional alloy (composition 6) (see FIG.
1
).
If the alloy is prepared under metallurgical production conditions, then scrap metal made of aluminum-magnesium alloys may be used as an additive.
The ingots were homogenized and machined to a thickness of 140 mm. They were subsequently hot-rolled to a thickness of 7 mm at a temperature of 400° C. and then cold-rolled to a thickness of 4 mm. The cold-rolled sheets were heat-treated in an electric oven. The heat-treated sheets were used as test material.
Standard transverse specimens removed from the sheets were used to determine the static tensile strength (R
m
, R
p0,2
, A) and the dynamic strength:
number of cycles to failure (N) in determining the low cycle fatigue (LCF), for which specimens having a notch factor of K
t
=2.5 and a maximum stress σhd max=160 MPa are used;
crack-propagation rate da/dN in a range of the stress intensity factor ΔK=31.2 MPam
0.5.
,
critical stress intensity factor K
C
in the state of planar stress, the width (B) of the specimen being 160 mm.
All tests were conducted at room temperature.
The test results are listed in FIG.
2
.
Table 2 verifies that the alloy of the present invention has a higher static and dynamic strength than the conventional alloy. This allows for a reduction of the weight of the structures made of the alloy according to the present invention by 10 to 15%, in order to reduce operating costs, which is particularly important to the aircraft industry. The high readiness of the alloy according to the present invention to operate under static and dynamic conditions, as well as the fact that the alloy according to the present invention is a naturally hard alloy having a high corrosion resistance and good weldability, allows one to use it for the construction of completely new aircraft and spacecraft, sea-going vessels, land-bound vehicles, and other vehicles wherein structural elements are joined by welding. The alloy according to the present invention may be used as base material in welded structures, and as a welding additive for welded connections.
TABLE 1
|
|
Chemical Composition, Weight %
|
Iron/
|
Compo-
Magne-
Tita-
Beryl-
Zirco-
Scan-
Manga-
Sili-
Sili-
Alumi-
|
Alloy
sition
sium
nium
lium
nium
dium
Cerium
nese
Copper
Zinc
Iron
con
con*
)
num
|
|
Alloy
1
5.0
0.01
0.0001
0.05
0.18
0.001
0.05
0.05
0.05
0.02
0.02
1
Ba-
|
of the
lance
|
Present
2
5.3
0.03
0.003
0.1
0.24
0.002
0.12
0.1
0.1
0.10
0.03
3.33
Ba-
|
Inven-
lance
|
tion
3
5.6
0.05
0.005
0.15
0.30
0.004
0.18
0.15
0.15
0.2
0.04
5
Ba-
|
lance
|
Expanded
4
4.5
0.005
0.00005
0.01
0.12
0.0005
0.02
0.01
0.01
0.01
0.02
0.5
Ba-
|
Level
lance
|
of the
5
6.0
0.1
0.01
0.2
0.36
0.008
0.25
0.25
0.25
0.5
0.08
6.25
Ba-
|
Ele-
lance
|
ments
|
Known
6
4.4
0.05
0.003
0.1
0.3
0.002
—
—
—
—
—
—
Ba-
|
Alloy
lance
|
|
*
)
Ratio of iron content to silicon content
|
TABLE 2
|
|
Properties of the Heat-Treated Sheets
|
LCF
|
[cycles]
da/dN,
|
(K
t
= 2.5;
[mm/cycle]
K
c
|
R
m
R
p0.2
A
σ
max
= 160
(ΔK = 31.2
[MPa m]
|
Alloy
Composition
[MPa]
[MPa]
[%]
MPa)
MPa m)
(B = 160 mm)
|
|
Alloy of the
1
390
275
17
150 · 10
3
2.3 · 10
−3
62
|
Present
2
400
280
16
140 · 10
3
2.5 · 10
−3
63
|
Invention
3
410
290
15
140 · 10
3
3.3 · 10
−3
62
|
Expanded
4
370
260
18
130 · 10
3
3.8 · 10
−3
62
|
Level of the
5
420
315
13
110 · 10
3
4.0 · 10
−3
60
|
Elements
|
Known Alloy
6
380
275
15
130 · 10
3
3.8 · 10
−3
62
|
|
Claims
- 1. A naturally hard aluminum alloy as a semifinished material for a structure, comprising:magnesium from 5.0 to 5.6 weight percent; titanium from 0.01 to 0.05 weight percent beryllium from 0.0001 to 0.005 weight percent; zirconium from 0.05 to 0.15 weight percent; scandium from 0.18 to 0.30 weight percent; cerium from 0.001 to 0.004 weight percent; manganese from 0.05 to 0.18 weight percent; copper from 0.05 to 0.15 weight percent; zinc from 0.05 to 0.15 weight percent; 0.04 to 0.24 weight percent total iron and silicon, a ratio of iron to silicon in a range of 1 to 5; and a balance of aluminum.
Priority Claims (1)
Number |
Date |
Country |
Kind |
00128050 |
Dec 2000 |
EP |
|
PCT Information
Filing Document |
Filing Date |
Country |
Kind |
PCT/EP01/14797 |
|
WO |
00 |
Publishing Document |
Publishing Date |
Country |
Kind |
WO02/50325 |
6/27/2002 |
WO |
A |
US Referenced Citations (1)
Number |
Name |
Date |
Kind |
6531004 |
Lenczowski et al. |
Mar 2003 |
B1 |
Foreign Referenced Citations (4)
Number |
Date |
Country |
198 38 018 |
Mar 2000 |
DE |
2 717 827 |
Sep 1995 |
FR |
2 085 607 |
Jul 1997 |
RU |
WO 0011232 |
Mar 2000 |
WO |