JPH0543970A - High strength aluminum alloy plating substrate - Google Patents

Abstract

PURPOSE:To provide an aluminum alloy substrate having high strength and excellent in plating properties. CONSTITUTION:One side or both sides of an Al alloy core material contg. 4.0 to 6.0% Zn and 1.0 to 2.5% Mg and furthermore contg. one or >= two kinds among 0.1 to O.7% Mn, 0.05 to 0.25% Zr, 0.03 to 0.10% V, 0.05 to 0.2% Ti and 0.1 to 1.0% Cu are cladded with an Al alloy surface material contg. 2.0 to 5.5% Mg, furthermore contg. one or two kinds of 0.1 to 1.3% Zn and 0.1 to 0.7 Cu and, if desired, contg. one or >= two kinds among 0.05 to 0.50% Mn, 0.05 to 0.20% Cr, 0.01 to 0.10% Zr and 0.01 to 0.10% Ti. In this way, the high strength aluminum alloy plating substrate capable of obtaining excellent strength only by heat treatment and furthermore having good plating properties can be obtd.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-strength aluminum alloy plated substrate having high strength mechanical properties and excellent plating properties.

[0002]

2. Description of the Related Art A widely used as a plated substrate
The l-Mg alloy has a good plating property as well as excellent mechanical properties and good workability, and is a suitable material for a plated substrate. Further, recently, even in a plated material, the surface smoothness of the material may be strictly required depending on its application. However, with plated materials,
The surface smoothness also depends on the surface smoothness of the plated substrate, and the surface of the plated material obtained from the substrate having many irregularities has many irregularities. Conventionally, such a demand has been met by a method of strictly limiting the content of impurities such as Fe and Si in the substrate to suppress the unevenness of the plated substrate, and a sophisticated polishing technique. In terms of adhesion of plating, it is better that the surface of the plated substrate has some irregularities, but since Al-Mg alloy has good plating properties as described above, surface irregularities are Even if the amount is reduced, plating can be performed without impairing the adhesiveness, and these requirements can be met.

[0003]

As described above, the Al-Mg alloy has excellent properties in some respects, but since it is a non-heat treatment type alloy, a substrate using this alloy can be used. It is softened by heat treatment such as annealing and is not hardened by the subsequent heat history, and its use is limited in applications requiring material strength. By the way, the reduction in the strength of the substrate after annealing can be dealt with by adopting a quenching-sensitive heat-treated alloy as a material and hardening it at room temperature or high temperature aging. As an alloy satisfying this condition, a heat treatment type Al-Zn-Mg based alloy can be mentioned.
However, this type of heat treatment type aluminum alloy is not good in the adhesion and stability of plating, and is slightly inferior in terms of plating property. Further, when the surface smoothness of the plating material is required, if the smoothness of the substrate is increased, the adhesiveness is further lowered and it becomes difficult to perform good plating. Therefore,
It is particularly difficult to apply a plated substrate made of a heat-treatable aluminum alloy to an application in which strict requirements regarding surface smoothness are made. As described above, conventionally, a material excellent in both strength and plating property has not been developed, and its use has been limited. The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a high-strength aluminum alloy-plated substrate having sufficient strength and proof stress and excellent plating properties.

[0004]

In order to solve the above-mentioned problems, the first invention of the high-strength aluminum alloy-plated substrate of the present invention is Zn: 4.0 to 6.0% by weight,
Mg: 1.0 to 2.5%, and Mn: 0.
1 to 0.7%, Zr: 0.05 to 0.25%, V: 0.
03-0.10%, Ti: 0.05-0.2%, Cu:
Contains one or more of 0.1 to 1.0%,
On one or both sides of an Al alloy core material, the balance of which is Al and unavoidable impurities, and by weight%, Mg: 2.0 to 5.5%.
In addition, Zn: 0.1 to 1.3%, Cu:
It is characterized in that it is clad with an Al alloy skin material containing one or two of 0.1 to 0.7% and the balance Al and unavoidable impurities.

The second aspect of the present invention is, by weight%, Zn: 4.0 to 4.0.
6.0%, Mg: 1.0 to 2.5%, and
Mn: 0.1 to 0.7%, Zr: 0.05 to 0.25
%, V: 0.03 to 0.10%, Ti: 0.05 to 0.
2%, Cu: 0.1% to 1.0%, one or more of which is Al, and the balance is Al and unavoidable impurities.
l One or both sides of the alloy core, on a weight% basis, Mg: 2.
0 to 5.5%, and Zn: 0.1 to 1.3
%, Cu: 1 or 2 kinds out of 0.1 to 0.7%, M
n: 0.05 to 0.50%, Cr: 0.05 to 0.20
%, Zr: 0.01 to 0.10%, Ti: 0.01 to
It is characterized in that it is clad with an Al alloy skin material containing one or more of 0.10% and the balance Al and unavoidable impurities. The third invention is,
The second invention is characterized in that the content of Fe and Si among the unavoidable impurities of the Al alloy skin material is 0.08% or less by weight.

Although the thickness of the substrate is not limited, the thickness of the substrate is 0.05
It is desirable to have a thickness of not less than mm and a clad rate of not more than 15%. The reason for this is that if the thickness is less than 0.05 mm, the amount of diffusion of elements between the skin material and the core material is large at the time of heat treatment, and stable strength and plating property cannot be obtained. This is because the ratio of the core material is small and the effect of improving the strength of the material is small.

[0007]

In other words, according to the present invention, the core material is cured by the heat history, and exhibits excellent strength as a whole. Further, the skin material clad on the desired surface of the substrate is reinforced with a high-strength core material although its strength is slightly low, and its excellent plating property enables a good and strong plating layer to be formed. Therefore, it is possible to meet a strict demand for smoothness. In the heat history, the diffusion of components that impair the strength and the plating property can be avoided as much as possible with the above-mentioned desirable clad thickness and clad ratio, and the adverse effect of the heat history can be prevented. Next, the action of each component in the core material and the skin material and the reason for limiting the content thereof will be described below. In addition,
All the contents described below are shown by weight%.

1. Core material (1) Zn, Mg Add to impart strength improving effect by age hardening. However, if Zn: less than 4.0% and Mg: less than 1.0%, the effect is not sufficient, while Zn: 6.0%.
%, Mg: If it exceeds 2.5%, not only there is no further improvement effect, but also the workability of the material is deteriorated, so the range was limited to this range. (2) Mn, Zr, V, Ti These elements have a grain refining effect and improve mechanical properties such as strength and ductility, so they are added by selection. However, Mn: 0.1%, Zr: 0.05%, V: 0.03
%, Ti: less than 0.05%, the above effect is not sufficient, while Mn: 0.7%, Zr: 0.25%, V:
If the content exceeds 0.10% and Ti: 0.2%, there is no further improvement effect, and conversely, these elements form a giant crystal and deteriorate the mechanical properties, so the content is limited to the above range. (3) Since it promotes the aging effect of Cu Zn and Mg and further improves the mechanical properties, it is added by selection. However, 0.1%
If it is less than 1.0%, the above effect is not sufficient, while if it exceeds 1.0%, the quenching sensitivity becomes large, and if the cooling rate after annealing is not made sufficiently large, it will not cure, so it was limited to the above range.

2. Skin material (1) Add Mg to increase the Mg strength and obtain a sound plated substrate surface. However, if it is less than 2.0%, the above effect is not sufficient, while if it exceeds 5.5%, the workability is deteriorated, so the range is limited to this range. (2) Zn, Cu By including these elements in the Al-Mg alloy,
Form defects evenly in the insulating oxide film on the alloy surface,
One kind or two kinds are added because the plating reaction on the surface of the material is uniformly promoted and the plating property is remarkably improved. However, if Zn: 0.1% and Cu: less than 0.1%, the above effect is not sufficient, while Zn: 1.3%, Cu: 0.7.
If it is contained in excess of%, the number of defects in the oxide film becomes too large and plating tends to become non-uniform, so the above range was made.

(3) Mn, Cr, Zr, Ti These elements have the effect of suppressing the coarsening of crystal grains and improve the surface smoothness by refining the surface texture. Therefore, at least one element is added. However, Mn: 0.05%,
If Cr: 0.05%, Zr, Ti: less than 0.01%, the above effect is not sufficient, while Mn: 0.50%, Cr
: 0.20%, Zr, Ti: When 0.10% is exceeded,
The compound itself consisting of these elements is coarsened and the workability is deteriorated, and the surface irregularities are increased, so the above range is set. (3) Fe, Si These elements form a compound with Al to increase surface irregularities, so that the content needs to be suppressed especially in applications where surface smoothness is required. It is desirable to make the content as small as possible, but if it exceeds 0.08%, the effect on the smoothness is large, so 0.08% was made the upper limit.

[0011]

EXAMPLES Examples (invention materials) of the present invention will be described below in comparison with comparative materials outside the scope of the invention. Al alloys A to J for core material having the composition shown in Table 1 and Al alloys a to j for skin material having the composition shown in Table 2 are melted by a usual melting method,
Some of them were further refined by smelting outside the furnace to reduce impurities as much as possible. These melts were poured into a mold to produce an ingot. The obtained ingot was faced under a normal condition and subjected to a homogenizing heat treatment. Further, for the Al alloy for core material, a hot-rolled sheet having a thickness of 8.0 mm is formed by hot rolling, and for the Al alloy for skin material, after hot rolling, cold rolling is performed to 1.0 mm.
A cold rolled sheet having a thickness of mm was used. The Al alloy J for core material and the Al alloys i, j for skin material are alloys having compositions outside the scope of the present invention.

These hot-rolled sheet and cold-rolled sheet are respectively made of a core material,
As the skin material, the skin material was superposed on both surfaces of the core material in the combinations shown in Table 3, the clad material was manufactured by hot rolling, and then the thickness was 1.0 mm by cold rolling. This clad material was heat-treated in a nitrogen gas atmosphere at 400 ° C. for 5 hours to obtain age-hardened plated substrates (inventive material and comparative material). In each plated substrate, the core material had a thickness of 0.9 mm, the skin material had a thickness of 0.1 mm, and the clad ratio was 10%. Further, in addition to the plated substrate, as comparative materials, comparative materials 9 to 11 obtained from Al alloys a, b and c for skin materials
Comparative materials 4 to 8 obtained from Al alloys i and j for skin materials and Comparative materials 1 to 3 obtained from Al alloy J for core materials were prepared.

The obtained plated substrate was subjected to pretreatment such as cleaning in preparation for the plating described later. After the zincate treatment was continued, a Ni plating layer having a film thickness of 10 μm was provided. Next, a test was conducted to evaluate the tensile properties, plating properties and surface smoothness of each plated substrate, and the results are shown in Table 3. The plating property evaluation test was carried out by a zincate film peeling test, and the surface smoothness evaluation test was carried out by a surface roughness measuring method.

As is clear from the results shown in Table 3, all of the invention materials had high strength and excellent plating property, and a good plating layer was formed. Among the inventive materials, 2 to 10 have improved surface smoothness,
In this case as well, the plating property was good. Also, Zn and C
Inventive materials 1 to 10 containing u were particularly excellent in plating property. On the other hand, the comparative materials 4 to 8 had sufficient strength but were slightly inferior in plating property, and the comparative materials 1 to 3 were excellent in plating property but were insufficient in strength. Comparative materials 9 to 11 were excellent in plating property and slightly good in surface smoothness, but were significantly inferior in strength.

[0015]

[Table 1]

[0016]

[Table 2]

[0017]

[Table 3]

[0018]

As described above, the high-strength aluminum alloy-plated substrate of the present invention has a Zn: 4.
0 to 6.0%, Mg: 1.0 to 2.5%, Mn: 0.1 to 0.7%, Zr: 0.05 to 0.2
5%, V: 0.03 to 0.10%, Ti: 0.05 to
0.2%, Cu: 0.1-1.0% of 1 or 2
One or both sides of an Al alloy core material containing at least one species and the balance being Al and unavoidable impurities, in wt%, Mg:
2.0 to 5.5%, and Zn: 0.1 to
1.3%, Cu: 0.1 to 0.7%, or 1 or 2
Seed, and optionally Mn: 0.05 to 0.50%,
Cr: 0.05 to 0.20%, Zr: 0.01 to 0.1
0%, Ti: 0.01 to 0.10% of 1 or 2
Since it is clad with an Al alloy skin material containing at least one of the above and the balance consisting of Al and unavoidable impurities, high strength can be obtained by heat treatment and good plating properties can be obtained, making it suitable for applications requiring strength. It can be provided as a plated substrate and has the effect of significantly expanding its applications. Further, if the content of Fe and Si among the unavoidable impurities of the Al alloy skin material is 0.08% or less by weight, the surface roughness of the skin material is reduced and the surface after plating becomes smooth. Therefore, it can be widely used in applications where strict surface smoothness is required.

Claims (3)

[Claims] 1. Zn: 4.0 to 6.0% by weight, M
g: 1.0-2.5%, Mn: 0.1
~ 0.7%, Zr: 0.05-0.25%, V: 0.0
3 to 0.10%, Ti: 0.05 to 0.2%, Cu:
Contains one or more of 0.1 to 1.0%,
On one or both sides of an Al alloy core material, the balance of which is Al and unavoidable impurities, and by weight%, Mg: 2.0 to 5.5%.
In addition, Zn: 0.1 to 1.3%, Cu:
A high-strength aluminum alloy-plated substrate containing one or two of 0.1 to 0.7%, and the balance being clad with an Al alloy skin material consisting of Al and unavoidable impurities. 2. Zn: 4.0-6.0% by weight, M
g: 1.0-2.5%, Mn: 0.1
~ 0.7%, Zr: 0.05-0.25%, V: 0.0
3 to 0.10%, Ti: 0.05 to 0.2%, Cu:
Contains one or more of 0.1 to 1.0%,
On one or both sides of an Al alloy core material, the balance of which is Al and unavoidable impurities, and by weight%, Mg: 2.0 to 5.5%.
In addition, Zn: 0.1 to 1.3%, Cu:
1 to 2 out of 0.1 to 0.7%, Mn: 0.0
5 to 0.50%, Cr: 0.05 to 0.20%, Zr:
0.01 to 0.10%, Ti: 0.01 to 0.10%, and at least one Al alloy skin material containing Al and inevitable impurities is clad. Characteristic high strength aluminum alloy plated substrate 3. Of the unavoidable impurities of Al alloy skin material, F
The high-strength aluminum alloy-plated substrate according to claim 1 or 2, wherein the content of e and Si is 0.08% or less by weight.