CA1071902A - Cold fabricatable aluminum alloy - Google Patents
Cold fabricatable aluminum alloyInfo
- Publication number
- CA1071902A CA1071902A CA222,122A CA222122A CA1071902A CA 1071902 A CA1071902 A CA 1071902A CA 222122 A CA222122 A CA 222122A CA 1071902 A CA1071902 A CA 1071902A
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- CA
- Canada
- Prior art keywords
- alloy
- aluminum alloy
- corrosion
- resistance
- cold
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Classifications
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C21/00—Alloys based on aluminium
- C22C21/06—Alloys based on aluminium with magnesium as the next major constituent
Abstract
ABSTRACT OF THE DISCLOSURE
The present invention provides a cold wrought aluminum alloy which has excellent corrosion resistance and stress corrosion cracking resistance and mechanical properties greater than those of the conventional corrosion resistant aluminum alloy, said alloy consisting essentially of a cold wrought aluminum alloy having essentially the following composition:
4 - 7 wt.% of Mg; more than 1 wt.% - 1.5 wt.% of Zn; 0.1 - 0.6 wt.% of Mn; at least one component selected from the group consisting of 0.05 - 0.5 wt.% of Cr, 0.05 - 0.25 wt.% of Ti and 0.05 - 0.25 wt.% of Zr;
and less than 0.5% of impurities, the balance being aluminum which has excellent ductility, corrosion resistance and high strength and a mechanical strength higher than conventional corrosion resistant aluminum alloys.
The present invention provides a cold wrought aluminum alloy which has excellent corrosion resistance and stress corrosion cracking resistance and mechanical properties greater than those of the conventional corrosion resistant aluminum alloy, said alloy consisting essentially of a cold wrought aluminum alloy having essentially the following composition:
4 - 7 wt.% of Mg; more than 1 wt.% - 1.5 wt.% of Zn; 0.1 - 0.6 wt.% of Mn; at least one component selected from the group consisting of 0.05 - 0.5 wt.% of Cr, 0.05 - 0.25 wt.% of Ti and 0.05 - 0.25 wt.% of Zr;
and less than 0.5% of impurities, the balance being aluminum which has excellent ductility, corrosion resistance and high strength and a mechanical strength higher than conventional corrosion resistant aluminum alloys.
Description
9C~;~
The present invention relates to a cold wrought aluminum alloy which has excellent ductility, corrosion resistance and high strength and a mechanical strength hiyher than conventional corrosion resistant aluminum alloys.
In general/ A~M~ type corrosion resistant aluminum alloys have excellent mechanical properties and corrosion resistance and accordingly, they have been used for large structures such as buildings, ships and bridges.
However, these alloys have disadvantages of high sensitivity for stress corrosion cracking because the inter-metallic compound of Mg2AQ3 is easily precipitated in the grain boundaries to cause grain boundary corrosion. Accordingly, in the conventional AQ-Mg type cold wrought alloy having high strength for example, the aluminum alloy in Japanese Industrial Standard H 4000 and 5083, the content of ~Ig has been decreased to overcome the disadvantages. However, these conventional i~
alloys have unsufficient mechanical strength for large struc-tures. These alloys have disadvantages of low elongation, as shown in the following Table 1. A~-Zn-Mg type ternary alloys having age hardenability have been known as high strength alloys which have excellent mechanical strength and weldability, however these alloys have disadvantages of in~erior corrosion resistance and stress corrosion cracking resistance.
The present invention provides a cold wrought aluminum alloy which has excellent corrosion resistance and stress corrosion cracking resistance and mechanical properties greater than those o~ the conventional corrosion resistant aluminum alloy.
Acco~din~ to the present inyention there is provided a cold wrou~ht aliminum allo~ Whlch has excellent coxrosion resistance and stress corro~on crackin~ resistance anld also ~ . '~ .
7~9~Z
excellent mechanical strength and elongation consistin~ essentially of a cold wrought aluminum allo~ having essentially the following composition: 4 - 7 wt.~ of ~g; more than 1 wt.% - 1.5 wt.% of Zn;
0.1 - 0.6 wt.% of Mn; at least one component selected from the group consisting of 0.05 - 0.5 wt.% of Cr, 0.05 - 0.25 wt.% of $i and 0.05 - 0.25 wt.% of Zr; and less than 0.5% of impurities, the balance being aluminum. The impurities are mainly Fe and Si and less than 0.1 wt.% of other impurities. This alloy is useful for large constructions such as buildings, ships and bridges. ¦
In said alloy, Cr can be substituted by 0.05 - 0.25 wt.
% of Ti and 0.05 - 0.25 wt.% of Zr, give excellent corrosion resistance, stress corrosion cracking resistance and mechanical strength. At least one of 0.05 - 0.25 wt.~ o Ti and 0.05 - 0.25 wt.
% of Zr can be added to said alloy containing Mn, to improve m~chanical strength.
The aluminum alloy o the presenk invention contains said components and has excellent corrosion resistance and high strength and is cold workable. The aluminum alloy is prepared without heat treatment for ageing and precipitating effect.
The mechanical strength of the alloy is improved but, workability and corrosion resistance are decreased by increasing magnesium content. Accordingly, the magnesium content is 4 - 7 wt.% preferably 4.5 - 6.5 wt.% to the alloy.
The mechanical strength of the alloy is not affected by the zinc content. Zinc is added to improve workability and to prevent grain boundary corrosion caused by grain boundary precipit-ation of Mg2A~3. An adverse affect of corrosion resistance and an age hardening phenomenon are found with more than 1.5 wt.% of zinc. Accordingly, the zinc content is more than 1.0 - 1.5 wt.%.
$he mechanical properties of strength and elongation, corrosion resistance, and stress corrosion cracking resistance of the alloy are remarkably improved by adding chromium anld manganese.
~ - 2 -~ q~L90~
The chromium and manganese content is 0.05 - 0.5 wt. %
preferably 0.1 - 0.3 wt.%of Cr; or 0.1 - 0.6 wt.%, preferably :
0.2 - 0.4 w-t.% of Mn; or 0.3 - 0.5 wt.% of ta-tal o-f Cr ~ Mn. -A coarse intermetallic compound is formed which adversely affects the mechanical properties and cold workability and corrosion ... . . .
-2a-~7~
resistance of the alloy with an excess of Cr and/or Mn.
The mechan:ical strength, corrosion resistance and stress -~
corrosion cracking resistance of the alloy are remarkably improved by adding titanium or zirconium as the addition of chromium or manganese. The titanium and zirconium content is 0.05 - 0.25 wt.%
preferably 0.07 - 0.15 wt.~.
An alloy having excellent elongation, corrosion resist-ance and stress corrosion cracking resistance similar to those of additions of Mn and improved mechanical strength superior to that of addition of Mn can be obtained by adding both of Mn and Ti or Zr.
It is possible that the alloy may contain small content or impurities such as iron or silicon as in conventional aluminum alloys. However, the corrosion resistance and mechanical proper-t~es of the alloy are adversely affected by the impurities.
Accordingly, it is preferable to decrease the impurities content to less than 0.4 wt.~. The impurities except iron and silicon is less than 0.01 wt.~ of each impurity and is less than 0.1 wt.%
of -total of impurities. Thus, the aluminum alloys of the present invention do not contain components in suhstantia~ amounts except AQ, Mg, Zn, Cr, ~n, Ti, Zr, Fe and Si.
The test results for various aluminum alloys of the present invention are given in the following Example for showing the characteristics of the alloys.
[Example]
Each aluminum alloy slab was prepared by casting each molten aluminum alloy having the formulation of Table 1 at the casting temperature of 750C in a permanent mould having mould cav-ity of150n~ x llOmm x`30 mm. The slab was scalped, was then homo-genized at 430C for 24 hourst was treated by a hot rolling at the same temperature, the product was then further treated by a cold rolling after surface washing to form a rolled product having . .
0~
thickness of 1.5 - 2 ~, and the rolled product was annealed at about 370C during 5 hours. The annealed product was used for various tests as softened alloy. The annealed product was treated by a cold rolling mill to give hardness of ]/4 ~1, and used for various tests as strain hardened alloy. The test methods are as follows.
(a) Tests for ultimate strength, 0.2% proof stress and elongation:
Japanese Industrial Standard Z 2201:
(b) Corrosion resistance test:
Japanese Industrial Standard D 0201.
(semi-immersing in artificial sea water for 6 months) The test pieces were ~sed for observation of corrosion on the surface after corrosive treatment, as well as for mechanical strength tests.
~tr_ss corrosion cracking test:
Corrosive solution: aqueous solution of 5% NaCQ
0.3% H2O2 Load: 70Q weight for 0.2% proof stress Time: Time to breaking (hr.) No breaking ones; 4000 - 5000 hr.
Note: (in following Tables) O: Softened alloy H: ~ Strain hardened alloy (corresponding to 1/4H) Sample Nos. 13 15: Reference alloy (15; 5083 alloy) ~ _ ' - , : .. , , . , . :
Z
Table 1 _ . mechanical properties formulation(%) (%) _ ~ ultimate elon~a-;~mple Mg. ~n Mn Cr Type strength 0.2 proof tion No . kg/mm 2 %
30.7 1 14.3 ` 31.0 5.0 1.0 0.44 _ _ H33.4 24.4 18.9 ~ O31.7 15.3 33.6
The present invention relates to a cold wrought aluminum alloy which has excellent ductility, corrosion resistance and high strength and a mechanical strength hiyher than conventional corrosion resistant aluminum alloys.
In general/ A~M~ type corrosion resistant aluminum alloys have excellent mechanical properties and corrosion resistance and accordingly, they have been used for large structures such as buildings, ships and bridges.
However, these alloys have disadvantages of high sensitivity for stress corrosion cracking because the inter-metallic compound of Mg2AQ3 is easily precipitated in the grain boundaries to cause grain boundary corrosion. Accordingly, in the conventional AQ-Mg type cold wrought alloy having high strength for example, the aluminum alloy in Japanese Industrial Standard H 4000 and 5083, the content of ~Ig has been decreased to overcome the disadvantages. However, these conventional i~
alloys have unsufficient mechanical strength for large struc-tures. These alloys have disadvantages of low elongation, as shown in the following Table 1. A~-Zn-Mg type ternary alloys having age hardenability have been known as high strength alloys which have excellent mechanical strength and weldability, however these alloys have disadvantages of in~erior corrosion resistance and stress corrosion cracking resistance.
The present invention provides a cold wrought aluminum alloy which has excellent corrosion resistance and stress corrosion cracking resistance and mechanical properties greater than those o~ the conventional corrosion resistant aluminum alloy.
Acco~din~ to the present inyention there is provided a cold wrou~ht aliminum allo~ Whlch has excellent coxrosion resistance and stress corro~on crackin~ resistance anld also ~ . '~ .
7~9~Z
excellent mechanical strength and elongation consistin~ essentially of a cold wrought aluminum allo~ having essentially the following composition: 4 - 7 wt.~ of ~g; more than 1 wt.% - 1.5 wt.% of Zn;
0.1 - 0.6 wt.% of Mn; at least one component selected from the group consisting of 0.05 - 0.5 wt.% of Cr, 0.05 - 0.25 wt.% of $i and 0.05 - 0.25 wt.% of Zr; and less than 0.5% of impurities, the balance being aluminum. The impurities are mainly Fe and Si and less than 0.1 wt.% of other impurities. This alloy is useful for large constructions such as buildings, ships and bridges. ¦
In said alloy, Cr can be substituted by 0.05 - 0.25 wt.
% of Ti and 0.05 - 0.25 wt.% of Zr, give excellent corrosion resistance, stress corrosion cracking resistance and mechanical strength. At least one of 0.05 - 0.25 wt.~ o Ti and 0.05 - 0.25 wt.
% of Zr can be added to said alloy containing Mn, to improve m~chanical strength.
The aluminum alloy o the presenk invention contains said components and has excellent corrosion resistance and high strength and is cold workable. The aluminum alloy is prepared without heat treatment for ageing and precipitating effect.
The mechanical strength of the alloy is improved but, workability and corrosion resistance are decreased by increasing magnesium content. Accordingly, the magnesium content is 4 - 7 wt.% preferably 4.5 - 6.5 wt.% to the alloy.
The mechanical strength of the alloy is not affected by the zinc content. Zinc is added to improve workability and to prevent grain boundary corrosion caused by grain boundary precipit-ation of Mg2A~3. An adverse affect of corrosion resistance and an age hardening phenomenon are found with more than 1.5 wt.% of zinc. Accordingly, the zinc content is more than 1.0 - 1.5 wt.%.
$he mechanical properties of strength and elongation, corrosion resistance, and stress corrosion cracking resistance of the alloy are remarkably improved by adding chromium anld manganese.
~ - 2 -~ q~L90~
The chromium and manganese content is 0.05 - 0.5 wt. %
preferably 0.1 - 0.3 wt.%of Cr; or 0.1 - 0.6 wt.%, preferably :
0.2 - 0.4 w-t.% of Mn; or 0.3 - 0.5 wt.% of ta-tal o-f Cr ~ Mn. -A coarse intermetallic compound is formed which adversely affects the mechanical properties and cold workability and corrosion ... . . .
-2a-~7~
resistance of the alloy with an excess of Cr and/or Mn.
The mechan:ical strength, corrosion resistance and stress -~
corrosion cracking resistance of the alloy are remarkably improved by adding titanium or zirconium as the addition of chromium or manganese. The titanium and zirconium content is 0.05 - 0.25 wt.%
preferably 0.07 - 0.15 wt.~.
An alloy having excellent elongation, corrosion resist-ance and stress corrosion cracking resistance similar to those of additions of Mn and improved mechanical strength superior to that of addition of Mn can be obtained by adding both of Mn and Ti or Zr.
It is possible that the alloy may contain small content or impurities such as iron or silicon as in conventional aluminum alloys. However, the corrosion resistance and mechanical proper-t~es of the alloy are adversely affected by the impurities.
Accordingly, it is preferable to decrease the impurities content to less than 0.4 wt.~. The impurities except iron and silicon is less than 0.01 wt.~ of each impurity and is less than 0.1 wt.%
of -total of impurities. Thus, the aluminum alloys of the present invention do not contain components in suhstantia~ amounts except AQ, Mg, Zn, Cr, ~n, Ti, Zr, Fe and Si.
The test results for various aluminum alloys of the present invention are given in the following Example for showing the characteristics of the alloys.
[Example]
Each aluminum alloy slab was prepared by casting each molten aluminum alloy having the formulation of Table 1 at the casting temperature of 750C in a permanent mould having mould cav-ity of150n~ x llOmm x`30 mm. The slab was scalped, was then homo-genized at 430C for 24 hourst was treated by a hot rolling at the same temperature, the product was then further treated by a cold rolling after surface washing to form a rolled product having . .
0~
thickness of 1.5 - 2 ~, and the rolled product was annealed at about 370C during 5 hours. The annealed product was used for various tests as softened alloy. The annealed product was treated by a cold rolling mill to give hardness of ]/4 ~1, and used for various tests as strain hardened alloy. The test methods are as follows.
(a) Tests for ultimate strength, 0.2% proof stress and elongation:
Japanese Industrial Standard Z 2201:
(b) Corrosion resistance test:
Japanese Industrial Standard D 0201.
(semi-immersing in artificial sea water for 6 months) The test pieces were ~sed for observation of corrosion on the surface after corrosive treatment, as well as for mechanical strength tests.
~tr_ss corrosion cracking test:
Corrosive solution: aqueous solution of 5% NaCQ
0.3% H2O2 Load: 70Q weight for 0.2% proof stress Time: Time to breaking (hr.) No breaking ones; 4000 - 5000 hr.
Note: (in following Tables) O: Softened alloy H: ~ Strain hardened alloy (corresponding to 1/4H) Sample Nos. 13 15: Reference alloy (15; 5083 alloy) ~ _ ' - , : .. , , . , . :
Z
Table 1 _ . mechanical properties formulation(%) (%) _ ~ ultimate elon~a-;~mple Mg. ~n Mn Cr Type strength 0.2 proof tion No . kg/mm 2 %
30.7 1 14.3 ` 31.0 5.0 1.0 0.44 _ _ H33.4 24.4 18.9 ~ O31.7 15.3 33.6
2 5.4 1.4 0.190.16 H34.6 25. 3 20. 5 33.9 1 16.0 30.0
3 6.2 1.0 0.44 _ .. H 36.9 2 6.6 21.0 O 33.1 15.9 32.1 _
4 6.5 0.72 0.200.15 _ EI 36.4 25.1 23.4 _ _ __ _ ;-o 33.0 15.2 31.5 6.4 1.3 0.200.14 __ l H 37.1 26.0 22.8 ~_ __ _ _ _ ' O 3~ .7 - lS.9 29.8 6 6.6 1.6 0.220.15 H 38. 6 28.6 18.9 ~ ' O-- -34.5 19.5 25.0 7 5.5 1.1 0.34 _ EI 35.9 27.9 16.8 _ _ O 39.5 24.2 19.8 ! 8 5.6 1.0 0.34 _ _ H 42.8 34.1 15.3 O 30.5 15.4 32.3
5.1 1.0 _ _ _ H 3 3. 6 24.9 20. 3 _ O 33.3 18.7 23.0 10 5 . O 1 . O _ _ __ _.
H 36.1 27.9 15 ~ 8 O 26.8 12.3 30.
5.0 1.0 _ _ H 33.2 ¦ 28.0 12,3 ~ -_ _ O 29.3 1 13.3 32.8 ~
12 6~2 1.0 _ _ ~ -H 36.1 30.8 14.S
_ ' O 29.4 15.7 2~ . ~
13 4.5 _ 0.540.17 _ _ _ .~ _ . _ H 36.5 33.0 ~ :9:.,0 ., :';
.. - .
~" "
,:
, ~ ~ ` .' ~7~9~:3Z
Table 2 ~-Sampl~ formulation (%) iType corrosion 'time to stress No. _ resistance 'corrosion test rating~cracking :
Mg Zn Mn Cr nu~er ~ (hr) O 9 I > 4000 1 5.Q 1.0 0.44 _ H 9 >4000 O 9 ~S000 2 5.4 1.4 0.19 0.16 _ EI 9 ~ 5000 ..
: O 8 ~4000 3 6.2 1.0 0.44 _ _ _ . H 7 >4000 _ . O 9 > 5000 4 6.5 0.72 0.20 0.1$
H . 9 ~ 5000 __ _ O . 9 ~ 5000 5 6.4 1.3 0.20 0.14 _ H 9 ~5000 _ ~__ _ .
O ~ ~5000
H 36.1 27.9 15 ~ 8 O 26.8 12.3 30.
5.0 1.0 _ _ H 33.2 ¦ 28.0 12,3 ~ -_ _ O 29.3 1 13.3 32.8 ~
12 6~2 1.0 _ _ ~ -H 36.1 30.8 14.S
_ ' O 29.4 15.7 2~ . ~
13 4.5 _ 0.540.17 _ _ _ .~ _ . _ H 36.5 33.0 ~ :9:.,0 ., :';
.. - .
~" "
,:
, ~ ~ ` .' ~7~9~:3Z
Table 2 ~-Sampl~ formulation (%) iType corrosion 'time to stress No. _ resistance 'corrosion test rating~cracking :
Mg Zn Mn Cr nu~er ~ (hr) O 9 I > 4000 1 5.Q 1.0 0.44 _ H 9 >4000 O 9 ~S000 2 5.4 1.4 0.19 0.16 _ EI 9 ~ 5000 ..
: O 8 ~4000 3 6.2 1.0 0.44 _ _ _ . H 7 >4000 _ . O 9 > 5000 4 6.5 0.72 0.20 0.1$
H . 9 ~ 5000 __ _ O . 9 ~ 5000 5 6.4 1.3 0.20 0.14 _ H 9 ~5000 _ ~__ _ .
O ~ ~5000
6 6.6 1.6 ! 0.22 0.15 _ . _ . H B ~5000 . .
O 9 >4000
O 9 >4000
7 5.5 1.1 0.34 _ .
H 9 >4000 . _ __ O 8 >4000
H 9 >4000 . _ __ O 8 >4000
8 5.6 1.0 0.34 _ H . 8 ~4000 _ _ O 9 _
9 5~1 1.0 ~ _ H 9 _ . .
_ _ _ O ~ _ 5 . O 1 . O _ _ _ H 8 _ :
_ __. ., .
O 8 2000 : -115.0 1.0 _ _ .
126.2 1.0 ._ _ : H 7~ 800 _ _ : O 8 2000 134.5 _ ~.54 0.17 _ _ _ ::
_ _ _ ' ' ' ~. ' ' -6- . ~
~ ir ~ ~ ~
~ 90Z
As shown in Table 1, the 0.2% proof stress of the softened alloy was substantially increased by adding Mn or both Mn and Cr. comparing to that of the reference. The elongation of the strain hardened allov was substantially improved by adding Mn or both Mn and Cr to be twice as high as that of the concentional 5083 alloy. The ultimate strength of the alloy containing about 6% of Mg is especially high.
The aluminum alloys of the invention have excellent mechanical properties and high ductility compared to the conven-tional corrosion resis-tant alloys, and accordingly, the aluminum alloys of the present invention have high value as an aluminum alloy ~or construction purposes. The mechanical s-trength of the alloy can be changed depending upon a content of Mg, and ac~ord:ing:ly the aluminum alloys can be used for var~ous appli~
cations.
The corrosion resistance and stress corrosion cracking resistance of alloy can be substantially improved by adding Mn or both Mn and Cr. Typical examples are given in Table 2.
As shown in the reference, the A~-Mg-Zn alloy contain-ing no Cr or Mn have corrosion resistance and stress corrosion cracking resistance which are same or lower than -those of the conventional corrosion resistan-t alloy of the 5083 alloy.
~lowever, the corrosion resistance and stress corroslon cracking resistance are substantially improved by adding Cr or Mn.
Although there is no example in Table 2, the alloys containing more than 1.5% of;Zn have inferior workability and inferior corrosion resistance which are not higher -than those of the S085 alloy even though Mn and Cr is added. Moreover, ageing and precipitation hardening phonomenon is found in alloys con-taining more than 1.5% of Zn. Accordingly they are not suitable as an alloy for fabrica-tion. The mechanical streng-th corrosion resistance and stress corrosion cracking resistance are improv-ed by adding 0.05 - 0.25% of Ti or Zr or both o~ them ins-tead o~ Cr - - . : .
11)7~ 2 The excellent properties of the aluminum alloys of the invention, as an extrudable alloy were compared to those of the references by measuring each resistance to plastic deformation.
The results are shown in Figure 1 which illustrates graphs of resistance to plastic deformation plotted against reduction -in cross section area for cast and forged alloys respectively of three AQ-containin~allo~s.The relation of the r~sistance to plastic deformation (Kg/mm2) (ordinate) and the reduction of sectional area (%)(abscissa) for the samples prepared by casting (upper graph) and for the samples prepared by forging 50% (lower graph) are shown in Figure 1 wherein o Mg: 5.4%, Zn: 1.1%, Mn: 0.18~, Cr: 0.1~%
Mg: 6.3~ Zn: 1.1% Mn: 0.19%, Cr: 0.15 x 5056 alloy.
The aluminum alloy containing 5.4~ oE Mg, 1.1'~ of Zn, 0.18~ of Mn and 0.14~ of Cr, and the aluminum alloy containing 6.3% of Mg, 1.1~ of Zn, 0.19% of Mn, and 0.15% of Cr and the 5056 ~
corrosion resistant aluminum alloy containing 5.4% of Mg were :
used for the tests.
The test method is as follows:
The alloys were respectively cast in each cylindrical permanent mould having mould cavity diameter of 60 mm and height of 200 mm. Each o cylindrical sample having diame~er of 15 mm and height of 18 mm was cut off from the center of the cast product. The results are shown in the upper graph.
Other cast product was forged by 50~, and then each of c~lindrical sample having diameter of 15 mm and height of 18 mm ~;
was cut off from the center of the product. The results are shown in the lower graph.
The compressing tests of each group of the samples were conducted at ~30C.
From the results, it is clear that the aluminum alloys ~ .
- 8 - ~
. .
1~7~
-of the present invention have superior workability to that of the 5056 alloy.
In accordance with the tests for extruding ~ach alum-inum alloy billet containing 6~1% of Mg, 1.0% of Zn, 0.13% of Cr and 0.13% of Mn, the pressure required for extrusion was lower than that of the 5083 alloy and the formation of pick up was smaller than that of the 5083 alloy. In accordance with the tests for extrusion at 530C in two heating steps (at 430C for 4 - 5 hours and then at 530C), the extrusion velocity for the alloy of the invention was higher than two times of tha-t of the 5083 alloy.
The aluminum alloy of the invention is also suitable as an extrudable alloy.
In addition, the alloy oE the invention shows so good weldability as 85~ of efficiency of joint in the welding test.
Formulation 5056 alloy 5083 alloy Mg 5.4 wt.% Mg 4.5 wt.%
Mn 0.0~ " Mn 0.54 "
Cr 0.1 " Cr 0.17 "
_ _ _ O ~ _ 5 . O 1 . O _ _ _ H 8 _ :
_ __. ., .
O 8 2000 : -115.0 1.0 _ _ .
126.2 1.0 ._ _ : H 7~ 800 _ _ : O 8 2000 134.5 _ ~.54 0.17 _ _ _ ::
_ _ _ ' ' ' ~. ' ' -6- . ~
~ ir ~ ~ ~
~ 90Z
As shown in Table 1, the 0.2% proof stress of the softened alloy was substantially increased by adding Mn or both Mn and Cr. comparing to that of the reference. The elongation of the strain hardened allov was substantially improved by adding Mn or both Mn and Cr to be twice as high as that of the concentional 5083 alloy. The ultimate strength of the alloy containing about 6% of Mg is especially high.
The aluminum alloys of the invention have excellent mechanical properties and high ductility compared to the conven-tional corrosion resis-tant alloys, and accordingly, the aluminum alloys of the present invention have high value as an aluminum alloy ~or construction purposes. The mechanical s-trength of the alloy can be changed depending upon a content of Mg, and ac~ord:ing:ly the aluminum alloys can be used for var~ous appli~
cations.
The corrosion resistance and stress corrosion cracking resistance of alloy can be substantially improved by adding Mn or both Mn and Cr. Typical examples are given in Table 2.
As shown in the reference, the A~-Mg-Zn alloy contain-ing no Cr or Mn have corrosion resistance and stress corrosion cracking resistance which are same or lower than -those of the conventional corrosion resistan-t alloy of the 5083 alloy.
~lowever, the corrosion resistance and stress corroslon cracking resistance are substantially improved by adding Cr or Mn.
Although there is no example in Table 2, the alloys containing more than 1.5% of;Zn have inferior workability and inferior corrosion resistance which are not higher -than those of the S085 alloy even though Mn and Cr is added. Moreover, ageing and precipitation hardening phonomenon is found in alloys con-taining more than 1.5% of Zn. Accordingly they are not suitable as an alloy for fabrica-tion. The mechanical streng-th corrosion resistance and stress corrosion cracking resistance are improv-ed by adding 0.05 - 0.25% of Ti or Zr or both o~ them ins-tead o~ Cr - - . : .
11)7~ 2 The excellent properties of the aluminum alloys of the invention, as an extrudable alloy were compared to those of the references by measuring each resistance to plastic deformation.
The results are shown in Figure 1 which illustrates graphs of resistance to plastic deformation plotted against reduction -in cross section area for cast and forged alloys respectively of three AQ-containin~allo~s.The relation of the r~sistance to plastic deformation (Kg/mm2) (ordinate) and the reduction of sectional area (%)(abscissa) for the samples prepared by casting (upper graph) and for the samples prepared by forging 50% (lower graph) are shown in Figure 1 wherein o Mg: 5.4%, Zn: 1.1%, Mn: 0.18~, Cr: 0.1~%
Mg: 6.3~ Zn: 1.1% Mn: 0.19%, Cr: 0.15 x 5056 alloy.
The aluminum alloy containing 5.4~ oE Mg, 1.1'~ of Zn, 0.18~ of Mn and 0.14~ of Cr, and the aluminum alloy containing 6.3% of Mg, 1.1~ of Zn, 0.19% of Mn, and 0.15% of Cr and the 5056 ~
corrosion resistant aluminum alloy containing 5.4% of Mg were :
used for the tests.
The test method is as follows:
The alloys were respectively cast in each cylindrical permanent mould having mould cavity diameter of 60 mm and height of 200 mm. Each o cylindrical sample having diame~er of 15 mm and height of 18 mm was cut off from the center of the cast product. The results are shown in the upper graph.
Other cast product was forged by 50~, and then each of c~lindrical sample having diameter of 15 mm and height of 18 mm ~;
was cut off from the center of the product. The results are shown in the lower graph.
The compressing tests of each group of the samples were conducted at ~30C.
From the results, it is clear that the aluminum alloys ~ .
- 8 - ~
. .
1~7~
-of the present invention have superior workability to that of the 5056 alloy.
In accordance with the tests for extruding ~ach alum-inum alloy billet containing 6~1% of Mg, 1.0% of Zn, 0.13% of Cr and 0.13% of Mn, the pressure required for extrusion was lower than that of the 5083 alloy and the formation of pick up was smaller than that of the 5083 alloy. In accordance with the tests for extrusion at 530C in two heating steps (at 430C for 4 - 5 hours and then at 530C), the extrusion velocity for the alloy of the invention was higher than two times of tha-t of the 5083 alloy.
The aluminum alloy of the invention is also suitable as an extrudable alloy.
In addition, the alloy oE the invention shows so good weldability as 85~ of efficiency of joint in the welding test.
Formulation 5056 alloy 5083 alloy Mg 5.4 wt.% Mg 4.5 wt.%
Mn 0.0~ " Mn 0.54 "
Cr 0.1 " Cr 0.17 "
Claims (3)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A cold wrought aluminum alloy having essentially the following composition: 4 - 7 wt.% of Mg; more than 1 wt.% -1.5 wt.% of Zn; 0.1 - 0.6 wt.% of Mn; at least one component selected from the group consisting of 0.05 - 0.5 wt.% of Cr, 0.05 - 0.25 wt.% of Ti and 0.05 - 0.25 wt % of Zr; and less than 0.5 wt.% of impurities and the balance being aluminum.
2. The aluminum alloy of Claim 1, which consists essentially of 4 - 7 wt.% of Mg; between 1.0 and 1.5 wt.%
of Zn; 0.1 - 0.6 wt.% of Mn; 0.05 - 0.5 wt.% of Cr; at least one member selected from the group consisting of 0.05 - 0.25 wt.% of Ti and 0.05 - 0.25 wt.% of Zr; less than 0.5 wt.% of impurities of the balance A?.
of Zn; 0.1 - 0.6 wt.% of Mn; 0.05 - 0.5 wt.% of Cr; at least one member selected from the group consisting of 0.05 - 0.25 wt.% of Ti and 0.05 - 0.25 wt.% of Zr; less than 0.5 wt.% of impurities of the balance A?.
3. The aluminum alloy of Claim 1, which consists essentially of 4 - 7 wt.% of Mg; between 1.0 and 1.5 wt% of Zn;
0.2 - 0.4 wt.% of Mn; 0.1 - 0.3 wt.% of Cr and 0.3 - 0.5 wt.% of total of Mn and Cr; less than 0.5 wt.% of impurities and the balance A?.
0.2 - 0.4 wt.% of Mn; 0.1 - 0.3 wt.% of Cr and 0.3 - 0.5 wt.% of total of Mn and Cr; less than 0.5 wt.% of impurities and the balance A?.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2938074A JPS5713616B2 (en) | 1974-03-14 | 1974-03-14 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1071902A true CA1071902A (en) | 1980-02-19 |
Family
ID=12274526
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA222,122A Expired CA1071902A (en) | 1974-03-14 | 1975-03-14 | Cold fabricatable aluminum alloy |
Country Status (6)
| Country | Link |
|---|---|
| JP (1) | JPS5713616B2 (en) |
| CA (1) | CA1071902A (en) |
| CH (1) | CH611340A5 (en) |
| DE (1) | DE2510087C2 (en) |
| FR (1) | FR2264095B1 (en) |
| GB (1) | GB1458181A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5935296A (en) * | 1995-09-19 | 1999-08-10 | Rees; Geraint | Bonded medium |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5137015A (en) * | 1974-09-24 | 1976-03-29 | Sumitomo Light Metal Ind | TEIONJINSEINOSUGURETA ARUMINIUM UGOKIN |
| JPS6043901B2 (en) * | 1980-05-31 | 1985-10-01 | 株式会社神戸製鋼所 | Non-heat treatment type Al-Mg alloy |
| JPS609927U (en) * | 1983-02-28 | 1985-01-23 | 斎藤 憲三 | Combination pocket with flap pocket and another pocket (box-shaped) |
| JPH0647704B2 (en) * | 1984-12-04 | 1994-06-22 | 三菱化成株式会社 | Aluminum alloy for casting |
| EP0799900A1 (en) * | 1996-04-04 | 1997-10-08 | Hoogovens Aluminium Walzprodukte GmbH | High strength aluminium-magnesium alloy material for large welded structures |
| EP1019217B1 (en) * | 1997-10-03 | 2002-05-02 | Corus Aluminium Walzprodukte GmbH | Aluminium-magnesium weld filler alloy |
| US7494043B2 (en) | 2004-10-15 | 2009-02-24 | Aleris Aluminum Koblenz Gmbh | Method for constructing a welded construction utilizing an Al-Mg-Mn weld filler alloy |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE940324C (en) * | 1937-07-25 | 1956-03-15 | Westfaelische Leichtmetallwerk | Payable aluminum alloys |
| GB1003264A (en) * | 1961-11-24 | 1965-09-02 | Aluminum Co Of America | Improvements relating to cold-worked aluminium-magnesium alloy articles |
-
1974
- 1974-03-14 JP JP2938074A patent/JPS5713616B2/ja not_active Expired
-
1975
- 1975-03-07 DE DE19752510087 patent/DE2510087C2/en not_active Expired
- 1975-03-11 CH CH316775A patent/CH611340A5/en not_active IP Right Cessation
- 1975-03-11 GB GB1007875A patent/GB1458181A/en not_active Expired
- 1975-03-13 FR FR7507827A patent/FR2264095B1/fr not_active Expired
- 1975-03-14 CA CA222,122A patent/CA1071902A/en not_active Expired
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5935296A (en) * | 1995-09-19 | 1999-08-10 | Rees; Geraint | Bonded medium |
Also Published As
| Publication number | Publication date |
|---|---|
| GB1458181A (en) | 1976-12-08 |
| DE2510087A1 (en) | 1975-09-18 |
| JPS5713616B2 (en) | 1982-03-18 |
| FR2264095A1 (en) | 1975-10-10 |
| DE2510087C2 (en) | 1986-02-27 |
| JPS50122411A (en) | 1975-09-26 |
| FR2264095B1 (en) | 1978-03-17 |
| CH611340A5 (en) | 1979-05-31 |
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