JPS585980B2 - High-strength aluminum alloy with excellent formability - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides A/-Cu that has both moldability and strength.
Or AJ! '-Cu-Mg-8i based high strength aluminum alloy.

In addition to being used as structural strength members, high-strength aluminum alloys are used in various cooling applications such as deep drawing in oil tanks, stretching and bending in automobile bodies, drawing or spinning in automobile wheels, and swaging in baseball bats. It is used in a wide range of applications, including intermediate machining processes.

However, high-strength alloys do not have sufficient formability even if they are low-temperature aged materials such as T4 material, so in many cases, they are first subjected to softening annealing and then subjected to heat treatment of quenching and aging after forming.

For this reason, the molding manufacturer itself must have heat treatment equipment for quenching, aging, etc., and carry out the heat treatment. Moreover, the heat treatment operation is complicated, and there are technical problems such as deformation due to distortion during quenching. This is a major economic problem and is a factor that limits the use of high-strength alloys for forming processing.

In order to overcome this current situation, it is absolutely necessary to impart good moldability to the T4 material itself, and several attempts have been made to this end.

For example, heat treatable alloys that have recently been developed for use in automobiles and are attracting attention all aim at this point.

However, the formability, particularly bending workability, is still insufficient for products that require strict molding conditions, such as four automobiles, and the reality is that a compromise is made with a design that loosens the molding conditions. .

In view of these circumstances, the present invention has been developed to dramatically improve the formability of low-temperature aged materials such as T4 material, and to withstand severe cold-open forming processing. -Cu system and AA'-Cu
- It is an object of the present invention to provide a high-strength Mg-8i alloy.

In order to achieve the above object, the inventors of the present invention have conducted extensive research on high-strength Al-Cu alloy compositions, and as a result, they have added formability by adding a small amount of an element selected from a specific group of low-melting heavy metal elements, and The present inventors have discovered that rough skin properties, strength, etc. can be improved by adding trace amounts of other specific transition metal elements and elements selected from the boron group, and have completed the present invention.

While conventional attempts to improve formability have been made by reducing the amount of main alloying elements at the expense of strength, the present invention achieves high strength by adding small amounts of specific elements without reducing strength. The major feature is that the molding processability has been significantly improved while maintaining or even increasing the .

That is, the present invention provides (1) An-2,0 to 5. O%Cu-based aluminum alloy (2) A/-1.0~4.0%Cu-0.05~1.0
%Mg-0.05-1.0 Si-based aluminum alloy, and (A) Sn0.01-0.5%, CdO,01=-0,
5%, one or more elements selected from the group consisting of In0.01~0.5 and CB) Mn0.05~1.5%, CrO,05~0.3
%.

Ti0.01-0.2%, ZrO, 05-0.3%, V
One or more elements selected from the group consisting of O002~0.3≠, Bo, and 001~0.1.

It is made by adding a combination of.

All of the alloys of the present invention are age hardening alloys, and Al-C
In the u alloy, Cu is used as an age-hardening element, and in the Ll-Cu→--Si alloy, Cu, Mg, and Si are used as age-hardening elements, and the above (2) and (
The moldability is significantly improved by the combined addition of elements belonging to group B).

The reasons for limiting each element will be explained in detail below.

The aluminum alloy according to the present invention includes Cu or Cu,
Each element of Mg and Si functions as an age hardening element.

In A11-Cu alloy, Cu2.0~5.0 ratio, AA
'-Cu-Mg-8i alloy, Cu1.0~94.
0 ratio, Mg 0.05-1.0 ratio, Si 0.05-1.0
Add a person in charge.

In any alloy, if each element is below the lower limit of the above range, sufficient strength cannot be obtained, while if it exceeds the above upper limit, the strength increases, but on the other hand, it is accompanied by deterioration of formability and toughness. I don't like it.

The elements Sn, Cd, and In belonging to Group A have the effect of improving moldability.

This effect is thought to be due to the following mechanism.

That is, the quality of moldability depends on the difficulty of sliding motion of dislocations introduced by molding, and the easier the sliding motion, the better the moldability.

In order to facilitate this sliding movement, it is necessary to prevent the upward movement of dislocations that requires the absorption of atomic vacancies, but each of the above elements binds strongly to the atomic vacancies and prevents the upward movement of dislocations. It brings about the effect of

As a result, sliding movement becomes easy and good moldability is achieved.

To obtain such an effect, SnO, 01~o, s%, Cd
One or more of O101-0.5% and In0101-0.5% are added.

If the amount is less than this range, the above effect will not be sufficient, and on the other hand, if it is added beyond this range, the effect will increase slowly compared to the amount added, which is not only disadvantageous in terms of cost, but also causes deterioration of corrosion resistance. Undesirable.

Among the elements belonging to group B, Mn, Cr, Zr, and V are effective in improving surface roughness, and Ti and B have the effect of refining the crystal grains of the ingot in addition to improving surface roughness.

Each of these elements also brings about secondary effects such as improved stress corrosion cracking resistance and increased strength.

In order to exhibit this effect, Mn0.05 to 1.5
%, CrO, 05-0.3%, TiO, 01-0.2%
, ZrO, 05-0.3%, Vo, 02-0.3, B
o, 001 to 0.1% of each element is added.

If it is less than the above range, the effect of addition is not sufficient, while if it exceeds this range, it will crystallize as a giant compound during agglomeration, resulting in undesirable deterioration of formability and toughness.

As impurities, the unavoidable components and amounts normally present in alloys of this type are allowed.

For example, it may contain Fe with a coefficient of 0.9 or less, Zn with a coefficient of 0.7 or less, and in the case of A/-Cu alloys, it may contain Fe with a coefficient of 0.9 or less.
Si or the like having a ratio of 5 or less may be present.

Next, the alloy of the present invention will be specifically explained with reference to Examples.

Examples A/-Cu system and A/- with various component compositions shown in Table 1
A Cu-Mg-8i alloy was melted to obtain a 401EII thick ingot, which was homogenized and annealed at 520°C for 24 hours.
It was immediately hot rolled to a thickness of 3.6cm, and then cold rolled to a thickness of 2U to obtain a plate.

This plate material was solution-treated at 525°C for 30 minutes, water-quenched, and left at room temperature for 3 months to produce T4 material, and its formability was measured. A T6 material was produced through aging treatment, and its tensile properties were measured.

The same high-temperature aging treatment is performed using AJCu-based specimen gold/I61-14.
For 150℃ x 24 hours, AA! -Cu-Mg-
3i series test gold/4615~25: 180℃
The test was carried out for 1.5 hours.

The measurement results of moldability and tensile properties are shown in Table 2.

In addition, the evaluation of formability was based on the occurrence of cracks at the minimum bending radius of 0.1xyx and 2u in the 180° bending test, and the Erichsen value (
-) and rough skin condition.

In the column of "bending test" in the same table, rAJ indicates "no cracking", rBJ indicates "microcracking", rCJ indicates "cracking", and in the column of "rough skin", rAJ indicates "no roughening",
rBJ displays "slightly rough skin" and rCJ displays "skin roughness noticeably."

Based on the results shown in Table 2 above, first A#-Cu
Regarding the alloys of the present invention (41 to 11) and the comparative material (,
%12~14), the present invention alloy (/I61~
It is recognized that the strength of Sample No. 11) is superior to any of the comparative materials (Scraps 12 to 14).

In addition, regarding formability, comparative material 412 has bendability,
Both Erichsen value and rough skin resistance are poor, and %13 contains Sn, so moldability is good but poor skin roughness.
In addition, %14 contains Mn but does not contain Sn, so its bendability and Erichsen value are poor;
161-11) are recognized to be excellent in all of bendability, Erichsen value, and skin roughness.

Similarly AA! -Cu-Mg-8i alloy, when comparing the present invention material (Jan. 15-21) and the comparative material (/1622-25), the strength of the present invention material (/1615-21) is the comparative material (,% 22 to 25), and it is recognized that the moldability has been significantly improved.

As is clear from the above description, A#-C according to the present invention
U-based alloys and A#-Cu-Mg-8i-based alloys satisfy both workability and strength, which are contradictory material properties. Not only is it economically advantageous because it can omit complicated processing steps such as heat treatment such as hardening and accompanying distortion correction, but it can also be applied to parts with strict dimensional accuracy, which was traditionally difficult to manufacture. We have removed the conventional restrictions on the application of this type of alloy, and have applied it to four automobile bodies, automobile-related parts such as bumpers and wheels, oil tanks, can bodies, snowmobile bodies, etc., as well as helmets, aluminum bats, and conductive cables. It can be applied to a wide range of applications such as joints, office machine parts, and optical equipment parts, and its industrial value is extremely high.

Claims (1)

[Claims] 1(a) Cu2.0-5.0%, (b) Sn0.01-5.0%
0.5% CdO, 01~0.5% or In0.01~
One or more types among 0.5%, (c) Mn0.05-1.5
%, Cr0.05-0.3%, Zr0.05-0.3%
, or Vo, containing one or more types from 02 to 0.3%,
A high-strength aluminum alloy with excellent formability, consisting of the balance A and unavoidable impurities. 2(a) Cn2.0-5.0%, (b) sno, 01-
0.5%cd0.01~0.5% or In0.01~
One or more types among 0.5%, (c) Mn0.05-1.5
'%, CrO, 05~0.3 ratio, ZrO, 05~0.3
% or Vo, one or more types from 02 to 0.3 section, (a)
Ti0.01-0.2 or Bo, 001-0.1%
A high-strength aluminum alloy with excellent formability, comprising one or more of the following, and the balance A [and unavoidable impurities]. 3(a) Cu1.0-4.0%, Mg0.05-1.0
% and SiO, 05-1.0%, (b) sno, 01
~0.5'%. CdO, 01-0.5% or In0.01-0.54
One or more of the following, (c) MnO, o5~1.5%, Cr
O, 05-0.3%, ZrO, 05-0.3%, VO,
A high-strength aluminum alloy having excellent formability and comprising one or more of 02 to 0.3% and the remainder being Al and unavoidable impurities. 4(a) Cu1.0-4.0%, Mg0.05-1.0
% and Si0.05-1.0%, (b) Sn0.01
~0.5%, Cd0001~0.5 or In0.0
One or more types among ratios 1 to 0.5, (c) Mn0.05 to 1
．． 5%, Cr0.05-0.3, ZrO, 05-0.
3% or Vo, one or more types from 02 to 0.3 section, (d
) Tio, o1-0.2 section or 80.001-0.1
A high-strength aluminum alloy with excellent formability, comprising one or more of the following, and the balance A/and unavoidable impurities.