JPS6152345A - Superplastic al alloy - Google Patents

Abstract

PURPOSE:To obtain an Al alloy having much superior superplasticity and fit for severer working conditions as compared with JIS5083 alloy without deteriorating the superior characteristics of the JIS5083 alloy by incorporating prescribed amounts of Cu and Be into the JIS5083 alloy. CONSTITUTION:This Al alloy consists, by weight, 3.5-6% Mg, one or more among 0.1-1% Mn, 0.05-0.35% Cr and 0.03-0.25% Zr, 0.12-2% Cu, 0.0001- 0.005% Be and the balance Al. The alloy may further contain one or more among 0.01-0.25% Ti, 0.0001-0.1% B, 0.01-0.2% each of V, Nb and Ta, 0.01- 0.5% each of Ni and W, 0.01-0.2% Mo, 0.01-0.10% Hf, 0.25-1.5% Zn, 0.01- 0.25% rare earth element and 0.01-0.5% each of Ge, Bi, Ag, Li, Sn, Sb and Cd by <=1.0% in total in case where the alloy does not contain Zn.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an Al alloy having excellent superplastic properties.

In general, a superplastic alloy is an alloy that exhibits an elongation of at least 300% when subjected to high-temperature tensile deformation at a predetermined processing speed at a selected temperature, usually within the range of 400 to 600°C. According to this superplastic alloy, it is possible to integrally mold objects with complex shapes or large objects by blow molding a sheet material using air pressure, as in the case of plastic molding, and in recent years it has been used for building panels and aircraft. Used for manufacturing parts, etc.

(Prior Art) Currently, superplastic Al alloys with various compositions have been found, one of which is J-55083 alloy.

This J-K85083 alloy has Mg: 4. O ~ 4.9%,
Mn: Q, 4-1.0%, Or: 0.05-0.2
It is a non-heat-treatable structural Al alloy having a composition (weight%) containing 5% and the rest consisting of Al and unavoidable impurities, which has excellent corrosion resistance and alumite surface treatment properties, and also has high strength. , high-temperature elongation, which is a criterion for evaluating superplastic properties, is also the initial strain rate: 1. l X l O-
”/sec, deformation temperature: 540TC1 condition 300-
It indicates the degree.

(Problems to be Solved by the Invention) As described above, the J-E15083 alloy has excellent properties and is therefore used in a wide range of fields. However, there was a problem that the superplastic property with an elongation of about 300-300 mm could not adequately cope with the severe processing conditions required. The purpose of this invention is to provide a superplastic Al alloy that has even better superplastic properties and can withstand even harsher processing conditions without impairing the excellent properties of this superplastic Al alloy. .

(Means for Solving the Problems) The inventors of the present invention have conducted extensive research to solve the above problems 'f' and have found that Mg: 3. Contains s ~ 6%,
Mn: 0. t~1q6, Or: 0.05~0.35
%, Zr: 0.03 to 0.25, and Kau: 0.12 to 2.
%, Bθ: 0.0001 to o, oos, and optionally Ti: 0. OIS-0.25%, B
:0.0001~0.1%, V:0.01~0.2q6
, kJb: 0.01.0.2%, Ta: 0. OI
No, 2%, lli:Q, Ql~0.5%, W
: 0.01~0.5%, Mo20, ol~0.2%
, Hf: 0.01-0.10%, Zn: 0.25-1.
5%, rare earth elements: 0.01-0.25%, G@: 0,
Ol~0.5%, Bi: 0.01~0.5
%, Ag: 0, 1 N0.5%, xJi:
0. IA-0.51, 8n: 0.01-0.5%,
Sb: 0.01-0.5%, Oll: 0.
llt or 2 or more of 1 to 0.5 and Zn
The result was an Al alloy having a composition in which the total amount of other components other than 1 was 1.0 or less, with the remainder consisting of Mu1 and unavoidable impurities.

The Al alloy of the present invention may contain Fe f as an unavoidable impurity, but if the content is 0
．． If it is 4% or less, the alloy properties will not be impaired in any way.

In addition, the Al alloy of the present invention is made into a slab by the normal melt MTS method, then subjected to homogenization treatment under the conditions of holding at a temperature within the range of 450 to 53 (L) for 1 to 48 hours, and then homogenized. The treated slab is subjected to hot pressing at a reduction rate of 30% or more at a temperature within the range of 250 to 530°C to form a hot rolled sheet, and then cooled at a working rate of 40% or more. The cold-rolled sheet is processed into a cold-rolled sheet having a final thickness by subjecting it to a cold-rolled sheet, but in this case, during homogenization treatment, the temperature rise to the treatment temperature is
It is desirable to gradually raise the temperature at 200/hr, which is K
Therefore, the superplastic properties are improved compared to homogenization treatment using a normal heating rate, but this is due to the fact that Mn, 0rS2p
This is due to the fact that the precipitation of zr and zr is made more uniform and finer.

Furthermore, in the Al alloy of the present invention, recrystallization occurs during the heating process to the deformation temperature or during the deformation process during super-tough deformation processing, so after cold rolling, recrystallization treatment is performed to impart superplastic properties. It is not necessarily necessary to do so.

(Function) This invention adds CufO312 to J-K85083 alloy.
~2- When B is added, the crystal grains become finer due to the recrystallization promoting effect, and the movement and sliding of one grain boundary is promoted. As a result, it exhibits even better superplastic properties, and B @ f, when 0.0001 to 0005 chi is included, ji! ! K is used to improve castability and hot pressure #IC properties as well as plastic properties, and T1 and B are added as necessary.
, V%llb, Ta, Ni, W.

MOLHf, Zn, rare earth elements, GoSBi, Ag, L
i.

Findings have shown that by containing one or more of Sn, Sb, and Od within the Kerr range, each of which is limited to the above, characteristic sounds such as superplasticity and mechanical properties can be further improved. It was created based on this.

Next, the reason why the composition range of the Al alloy of the present invention is limited as described above will be explained.

(a) Mg The Mg component has the effect of improving superplastic properties by refining crystal grains by promoting recrystallization, as well as strengthening the 1st alloy and imparting superior corrosion resistance. If the content is less than 0.5 inch, the desired effect cannot be obtained, while if the content exceeds 6 inch, the hot and cold workability may be deteriorated.
It was set at 5-6%.

(b) Mn, Or, and Zr These components precipitate uniformly and finely from the base material, which is a supersaturated solid solution, during casting II'1 refinement and further leveling treatment or hot working, and thus It has the effect of suppressing crystal grain recovery and recrystallization and refining recrystallized grains, but the content is less than Mn: 0.1'1, respectively.
Or: Q, 05% undropped, and zr: o, oa chi groove did not have the desired effect, whereas Mn
:1g, Or:0.35%, and Zr:0.25g, especially in the case of large ingots, giant gold α-intercompounds of these components crystallize. y<>, as this results in a deterioration of the superplastic properties,
This content 3: Mn: o, i ~1%, respectively
, Or no, o 5-0.35%, and zr:
Q, O3N0. It was set as z5chi.

(c) The 0u Cu acid component not only strengthens the matrix but also refines crystal grains by promoting recrystallization, promotes movement and sliding of crystal grains, and improves superplastic properties and optimal deformation processing temperature. However, if the content is 0. If the content is less than 2%, the desired excellent super-temperature properties cannot be secured, while if the content exceeds 2%, hot working and cold working become difficult.
Its content was determined to be 0.12 to 2 inches.

(a) The B-Be component improves superplastic properties, shifts the temperature range of superplastic properties to the low temperature side, prevents slab cracking during casting, and further improves hot workability. However, if the content is less than 0.0001%, the desired effect cannot be obtained, while if the content exceeds 0.00596, the hot and cold workability is completely reduced. was determined to be 0.0001 to o, ooschi.

(-) Ti, B, V, Nb, Ta%lli, W
, M0. and Tlt These components, like Mn, Or, and Zr, are refined by refining the casting structure, and then uniformly and finely precipitate from the supersaturated solid solution substrate during homogenization treatment or hot working, thereby forming recrystallized grains. The action of refining t4 improves the superheavy properties, but the content is T1, V
, Wb, Ta1111, W, Mo.

If less than 0.01-, B: 0.0OO
If the temperature is less than t, the desired effect cannot be obtained;
i: 0.25%, B: 0.196. lli:
0.5%, W: 0.5%, Ht: o, 1ofbtt
and V, Wb, Ta.

When Mo contains more than 0.2 h of each,
Giant intermetallic compounds of these components tend to crystallize, resulting in deterioration of superheavy properties, as well as deterioration of hot and cold workability and toughness. .01-0.25%, B: 0.
0001~0.1%, V: 0.01~0.2
%,llb: 0.01~0.2%,'ra:
0.01~0.2-1llt: o, ol~0.5%,
W: 0. O2N2.59G, MO: 0.01~0
．． 2%, oh! Hf: Set at 0.01 to 0.10%.

(f) Zn, rare earth elements, Go, Bi, Ag> and Li These components have many effects of strengthening the alloy and improving stress corrosion cracking resistance.
n: less than 0.25-, rare earth elements: less than 0.01-, Ge: o, less than ot*, ni: o, less than al1, 5 g
: less than 0.1% and Li: less than 0.1%, the desired effect cannot be obtained, while Zn: 1.5%, rare earth element: 0.25%, and Ge, Bi, Ag.

When Ll contains more than 0.5 h of each,
Due to reduced corrosion resistance, toughness, and superplastic properties,
The content is Zn: 0.25-1.5%, rare earth element:
0.01-0.25%, Ge: 0.01-0.5%, B
i: 0.01 to 0.5%, Ag: Q, 1 to 0.5%, and I, i: Q, 1 to 0.5%.

(g) sn, sb, and oa These component pressures have the effect of promoting grain movement and grain boundary sliding, thereby improving superplastic properties.
Its content is sn:Q, less than 91%, 81):0.01
If Eln, Sb, or 06 contains more than 0.5 Ti, corrosion resistance, toughness, and superplastic properties will decrease. Therefore, its content t-8n
: 0.01-0.5%, Sb: 0.01-0.5
% and aa: 0.1 to 0.5 h.

In addition, if the total amount of other components excluding Zn among the components shown in the above (eL (f) and (→) items is contained in an amount exceeding 1.0-, hot and cold workability will deteriorate. , toughness, corrosion resistance,
Since the superplastic properties etc. decrease, the total content K
It was set at 1-1.0% or less.

(Example) Al alloys 1 to 23 of the present invention and comparative alloy 1 having the component compositions shown in Table 1 were formed by a normal melting and casting method.
After preparing alloys 1 to 8 and casting them into ingots, 100
The temperature was gradually raised to 500 °C at a temperature increase rate of °C/hr, and homogenization was performed under the condition of holding this temperature for 4 hours. Then, the ingot was hot rolled at a rolling start temperature of 480'eK. Plate thickness: A hot-rolled plate with a thickness of 8 mm, followed by cold rolling on this hot-rolled plate under normal conditions to a final plate thickness of 71.6 mm.
It was made into a cold rolled sheet of mm.

Therefore, for the purpose of evaluating the superplastic properties of the resulting cold-rolled sheets of the present invention Al alloys 1 to 23 and comparative Al alloys 1 to 8, the deformation temperature was 530°C and the heating time to the deformation temperature was determined. : 10 minutes, initial strain rate: 1.1X10-
A high-temperature tensile deformation test chain was conducted under the conditions of '/θθC, and the total elongation was measured. The measurement results are also shown in Table 1.

In addition, the present invention Al alloys 1 to 23 and comparative Al alloys 1 to 23
After blow-forming the cold-rolled sheet No. 8 at a deformation temperature of 530° C., a tensile test was conducted at room temperature to measure the tensile strength. The measurement results are also shown in Table 1. 1 (Effects of the Invention) From the results shown in Table 1, the Al alloys 1 to 23 of the present invention all have excellent superplastic properties with an elongation of 8380% or more, and are comparable to the conventional J-55083 alloy. It is clear that the superplastic properties are much better than Al Alloy 8. Furthermore, as seen in Comparative Al Alloys 1 to 7, if the content of any of the constituent components (marked with * in Table 1) falls outside the scope of this invention,
It is also clear that the desired excellent superplastic properties cannot be ensured.

Furthermore, it can be seen that Al Alloys 2 and 4 to 23 of the present invention are superior to Comparative Al Alloy 8 not only in superplastic properties but also in tensile strength after forming.

As mentioned above, the Al alloy of the present invention has conventional superplastic Al
It has superior superplastic properties compared to the J-85083 alloy, which is known as an alloy.

Claims (2)

[Claims] (1) Contains Mg: 3.5-6%, Mn: 0.1-1
%, Cr: 0.05-0.35%, Zr: 0.03-0
．． Cu: 0.12-2%, Be: 0.0001-0.00
A superplastic Al alloy characterized by having a composition (weight %) containing 5% Al and the remainder consisting of Al and unavoidable impurities. (2) Contains Mg: 3.5-6%, Mn: 0.1-1
%, Cr: 0.05-0.35%, Zr: 0.03-0
．． Cu: 0.12-2%, Be: 0.0001-0.00
5%, further Ti: 0.01-0.25%, B
:0.0001~0.1%, V:0.01~0.2%,
Nb: 0.01-0.2%, Ta: 0.01-0.2%
, Ni: 0.01-0.5%, W: 0.01-0.5%
, Mo: 0.01-0.2%, Hf: 0.01-0.
10%, Zn: 0.25-1.5%, rare earth element: 0.
01-0.25%, Ge: 0.01-0.5%, Bi:
0.01-0.5%, Ag: 0.1-0.5%, Li:
0.1-0.5%, Sn: 0.01-0.5%, Sb:
Contains one or more of the following: 0.01 to 0.5%, Cd: 0.1 to 0.5%, and the total amount of other components other than Zn is 1.0% or less A superplastic Al alloy characterized by having a composition (the above weight %) consisting of Al and unavoidable impurities.