WO1999034026A1

WO1999034026A1 - Aluminum-alloy spring materials, leaf springs made of the materials for magnetic recording tape cassettes, tape cassettes provided with the leaf springs and process for the production of the materials

Info

Publication number: WO1999034026A1
Application number: PCT/JP1998/005909
Authority: WO
Inventors: Yoshihito Inabayashi; Youichirou Bekki; Kouichi Suzuki; Toshio Niituma
Original assignee: The Furukawa Electric Co., Ltd.; Tdk Corporation
Priority date: 1997-12-25
Filing date: 1998-12-25
Publication date: 1999-07-08
Also published as: DE19882142T1

Abstract

Aluminum-alloy spring materials which each contain 0.3 to 2.0 wt.% (exclusive of 2.0 wt.%) of Mg, 0.1 to 1.5 wt.% of Si, 0.1 to 3.0 wt.% of Cu and, if necessary, 0.01 to 1.5 wt.% of Mn, and, if necessary as further additional component(s), 0.01 to 0.5 wt.% of Cr, 0.01 to 0.2 wt.% of Zr, 0.01 to 0.2 wt.% of V, 0.01 to 0.2 of Sc, 0.001 to 0.2 wt.% of Ti and/or 0.0001 to 0.05 wt.% of B, with the balance being composed of Al and unavoidable impurities.

Description

Specification

Aluminum alloy spring material, leaf spring for magnetic recording tape cassette made of this spring material, tape cassette provided with this leaf spring, and method of manufacturing said spring material

The present invention provides an aluminum alloy spring material suitable for electronic devices such as a magnetic recording tape cassette, in which the spring force has been reduced with time in the initial stage, and a magnetic material using the spring material. The present invention relates to a leaf spring for a recording tape cassette, a tape cassette provided with the leaf spring, and a method for producing the spring material.

Background art

As shown in FIG. 1, the material of the anti-spin leaf spring 2 of the pair of reels 1 of the magnetic recording tape cassette is made of a non-magnetic, rust-resistant, stainless steel material. Stainless steel, such as 4, is used. Because the stainless steel is heavy and expensive, the leaf spring 2 is made of aluminum alloy spring material, which is light and inexpensive. It is desired to configure.

However, in the case of a magnetic recording tape cassette, the temperature in the deck rises to 40 to 70 ° C during use, so that ordinary aluminum alloys such as 3003 alloy and 518 alloy are used. The problem with um alloy spring materials is that the spring force deteriorates over time.

This rise in operating temperature is a general trend not only for magnetic recording tape cassettes but also for smaller and lighter electronic devices.

With respect to the deterioration of the spring force over time due to the rise in operating temperature, Although measures have been taken to increase the amount of solid solution elements in aluminum alloys and to finely disperse precipitates, sufficient effects have not yet been obtained.

In the case of aluminum alloy spring materials, in addition to the time-dependent deterioration of the spring force, the spring is locally plastically deformed when the spring is pressed several times after the spring is formed. There's a problem .

The initial stage is improved by increasing the heat resistance, but in the case of conventional materials, if the heat resistance is increased by cold working, the residual stress after spring forming increases. The problem is that the spring force deteriorates with time.

An object of the present invention is to provide an aluminum alloy spring material in which the initial deterioration and the deterioration with time of the spring force are improved.

Another object of the present invention is to provide a leaf spring for a magnetic recording tape cassette made of the above aluminum alloy spring material.

Still another object of the present invention is to provide a magnetic recording tape cassette provided with the above-described leaf spring for a magnetic recording tape cassette.

Still another object of the present invention is to provide a method for producing the above aluminum alloy spring material.

DISCLOSURE OF THE INVENTION

In order to achieve the above-mentioned purpose, the present inventors dissolve the alloy element in a supersaturated solid solution, and precipitate it by aging by increasing the temperature during use to increase the spring force. Investigations were made on methods to suppress the aging of steel, and among them, the A 1 —Mg—Cu system or A 1 —Mg—Si system precipitates were effective in preventing the aging of spring force. To find this knowledge Based on the observations, research was conducted on spring materials of A1-Mg-Si-Cu alloys.

As a result, if the amount of Cu in the alloy element is increased or aging treatment is performed under specified conditions to increase the power resistance, the initial force is prevented without deterioration of the spring force with time. I found what I could do. It was also found that the addition of Mn to this alloy system further improved the aging deterioration of the spring force in the initial stage.

Based on these findings, the present inventors have conducted intensive studies, and as a result, have developed an aluminum alloy spring material and an spring material that have improved both initial shear and aging of spring force over time. The present invention has succeeded in inventing a leaf spring for a magnetic recording tape force set using a material, a tape cassette provided with the leaf spring, and a method of manufacturing the spring material.

That is, according to the present invention, Mg of 0.3% by weight or more and less than 2.0% by weight, 0.3 :! to 1.5% by weight. /. The present invention provides an aluminum alloy spring material containing Si of the present invention and 0.1 to 3.0% by weight of Cu, and comprising the balance of A 1 and unavoidable impurities. .

Such an aluminum alloy spring material may further contain 0.01 to 1.5% by weight of Mn, if necessary. Also, if necessary, 0. 0 1 ~ 0. C r, of 5 wt ^_0/0 0. 0 1 to 0.2 weight. /. Zr, 0.01 to 0.2 weight. /. V, 0.01 to 0.2% by weight Sc, 0.001 to 0.2% by weight, and 0.001 to 0.05% by weight B force It may further contain at least one species selected from the group strengths.

Further, a conversion coating film, a resin coating, or both a conversion coating and a resin coating are formed on the surface of the aluminum alloy spring material of the present invention. Yes.

Further, according to the present invention, there is provided a leaf spring for a magnetic recording tape cassette comprising the above-described aluminum alloy spring material.

Further, according to the present invention, there is provided a magnetic recording tape cassette comprising a pair of reels around which a magnetic recording tape is wound, and the above-described leaf spring attached to these reels. Is provided.

Further, according to the present invention, Mg of 0.3% by weight or more and less than 2.0% by weight, 0.3 :! to 1.5% by weight. /. Aluminum alloy plate containing Si of 0.1% by weight and 0.1 to 3.0% by weight of Cu, the balance being A1 and unavoidable impurities. A step of solution-treating at a temperature of ° C, and cooling the solution-treated aluminum alloy plate to a temperature of 100 ° C or less at a cooling rate of 100 ° CZ or more. And a step of cold rolling the cooled aluminum alloy sheet. A method for producing an aluminum alloy spring material is provided.

The above method for manufacturing an aluminum alloy spring material is based on the aging method in which a cold-rolled aluminum alloy plate is heated at a temperature of 80 to 180 ° C for 1 hour to less than 10 hours. A process for performing the treatment may be further provided.

The aluminum alloy plate described above weighs 0.01 to 1.5 as required. /. Of Mn may be further contained. Also, if necessary, 0.01 to 0.5 weight. / ₀ Cr, 0 · 0 1 to 0.2 double weight ⁰ / ο Zr, 0.01 to 0.2 weight ⁰ V, 0.01 to 0.2 weight. /. Sc, 0.001 to 0.2 weight. /. Selected from the group consisting of Ti, and 0.001 to 0.05% by weight of B force. At least one additional species may be included.

In the method for producing an aluminum alloy spring material of the present invention, the cold rolling step is performed under such conditions that the surface temperature of the rolled material after cold rolling is 70 ° C. or higher, The method may further include a step of winding the rolled material after cold rolling into a coil.

Further, the method for producing an aluminum alloy spring material of the present invention includes a chemical conversion treatment and a resin coating treatment of baking at a temperature of 260 ° C. or less on the rolled material after cold rolling. A step of performing at least one of the treatments may be further provided.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is an explanatory view of a leaf idling prevention leaf spring of a magnetic tape cassette.

2A and 2B are a plan view and a side view illustrating a leaf spring used in a magnetic tape cassette.

BEST MODE FOR CARRYING OUT THE INVENTION The aluminum alloy spring material of the present invention contains Mg, Si, and Cu as essential elements. Each of these essential elements precipitates when the temperature rises during use, and has the effect of suppressing the deterioration with time of the spring force.

If the content of Mg is less than 0.3% by weight, the effect cannot be sufficiently obtained. If the content of Mg is more than 2.0% by weight, the strength becomes too high, so that the cold workability is reduced and the mass productivity is reduced. Getting worse . Therefore, the content of Mg is 0.3% by weight or more and 2.0% by weight. /. Stipulated below. The content of M g is 0 and rather is preferred. 6 to 1.8 wt%, further rather is preferred, Ru Oh at 0.8 to 1.8 wt ^_0/0. The content of Si is 0.1 weight. /. If the amount is less than 1.5%, the effect cannot be sufficiently obtained. If the amount exceeds 1.5% by weight, the strength becomes too high and the cold workability is reduced, and the mass productivity is deteriorated. Therefore, the content of Si is 0.1 to: 1.5 weight. / ₀ .

As described above, Cu is the most important alloying element. If its content is less than 0.1% by weight, its effect cannot be sufficiently obtained, and if it exceeds 3.0% by weight, it will be cold. Therefore, the content of Cu is specified in the range of 0 :! to 3.0% by weight./ The content of Cu is preferable. 0.4 to 2.0% by weight / ₀ , and more preferably 0.4 to 1.2% by weight.

The aluminum alloy spring material of the present invention preferably contains する η as necessary.

Μη raises the power resistance to prevent initial settling, and does not involve the deterioration of the spring force over time. Its content is 0.01 weight. /. If the value is less than the above, the power resistance cannot be sufficiently improved, and it does not contribute to the improvement in the initial stage. On the other hand, if it exceeds 1.5% by weight, giant crystals are formed and the fatigue properties deteriorate. Therefore, the content of ηη is specified to be 0.01 to 1.5% by weight.

The aluminum alloy spring material of the present invention may further include one or more of Cr, Zr, V, Sc, Ti, and B as optional elements as necessary. Preferably contains two or more species.

Each of the selected elements Cr, Zr, V, Sc, Ti, and B has an effect of making recrystallized grains fine, and prevents roughening when press-formed into a spring shape.

The content of these alloying elements is from CrO.01 to 0.5 weight. / ₀ , ZrO.01-0.2 weight. /. , V0.0 :! ~ 0.2 weight. / ₀ , ScO.01-0.2 weight. /. , Ti 0.001 to 0.2 weight. /. , BO.001-0.05 weight. Specified in / o. The reason is that if each is below the lower limit value, a sufficient refining effect cannot be obtained, and if each exceeds the upper limit value, corrosion resistance and workability deteriorate.

In the present invention, with respect to 0.2% heat resistance, the initial force tends to be slightly larger at 300 MPa or less, and the deterioration of the spring force with time is slightly larger at 450 MPa or more. Therefore, it is desirable that the pressure be more than 300 MPa and less than 45 OMPa. By forming a chemical conversion film, a resin film, or both of a chemical conversion film and a resin film on the surface of the aluminum alloy spring material of the present invention described above, the corrosion resistance and the corrosion resistance are improved. It is possible to improve press formability.

The chemical conversion film can be formed by chromate chromate treatment, phosphoric acid chromate treatment, or the like.

The resin film is a resin film such as epoxy, acrylic, vinyl chloride, or urethane, or a resin film mixed with a lubricant such as wax. You.

When forming both of the above-mentioned films, a resin film is usually formed on the chemical conversion film. However, by forming both films in this manner, corrosion resistance and pre-treatment are improved. The moldability is further improved.

A chemical conversion coating, a resin coating, or an aluminum alloy spring material with both coatings formed on the surface can use volatile oil as the lubricating oil during press molding. The lubricating oil washing step can be omitted. It is desirable that the thickness of the chemical conversion film, the resin film, or the film on which both films are formed be not more than Ομμηη, since it is difficult for the gas to adhere during press molding.

Next, a method for manufacturing the above-described aluminum alloy spring material of the present invention will be described.

In the method of the present invention, first, an aluminum alloy plate is subjected to a solution treatment. The aluminum alloy sheet subjected to the solution treatment is any solid or rolled sheet having a predetermined alloy composition. That is, a DC-formed ingot, a hot-rolled plate of this ingot, a cold-rolled plate of this hot-rolled plate, a continuous-formed-rolled plate, a cold-rolled plate of this continuous-rolled plate What is it?

In the method of the present invention, the alloy element is dissolved in supersaturation in the solution treatment step, and a part of the supersaturated solid solution element is cooled by a predetermined cooling rate after the solution treatment or is specified. Precipitation by aging treatment under the specified treatment conditions increases the heat resistance, prevents initial settling, and raises the temperature during use of the remaining supersaturated solid solution elements (for example, 40 to (70 ° C) to prevent the spring force from deteriorating over time.

In the method of the present invention, the reason for setting the solution heat treatment temperature to 400 to 550 ° C is that when the solution heat treatment temperature is less than 400 ° C, the alloy elements are sufficiently supersaturated to form a solid solution. If the temperature exceeds 550 ° C, the alloy plate will melt locally.

After solution treatment, rapid cooling at a cooling rate of 100 ° C / min or more to a temperature of 100 ° C or less is because the amount of over-saturated solid solution is insufficient if this condition is not satisfied. It is possible to suppress the deterioration of the spring force over time. There is no such thing.

In the method of the present invention, the resistance to heat can be increased by cold working, but the resistance to heat can be further increased by aging treatment.

In the method of the present invention, it is preferable that the aging treatment is performed by heating at a temperature of 80 to 180 ° C for 1 hour or more and less than 10 hours because the temperature is less than 80 ° C. Even if the time is less than 1 hour, it is difficult to increase the heat resistance by + minute, and the supersaturation tends to decrease even if the temperature exceeds 180 ° C or the time exceeds 10 hours. This is because the amount of precipitation during use is reduced, and it is difficult to suppress the deterioration of the spring force with time.

It is more desirable to carry out natural aging at a temperature of 30 to 70 ° C for 1 hour or more before aging treatment, because the aging treatment improves the heat resistance more. New

In the method of the present invention, a method is used in which a rolled material is wound around a coil at a temperature of 70 ° C. or more by utilizing heat generated during cold rolling, and aging treatment is performed during the slow cooling process of the coil. You can do it.

To increase the surface temperature during coiling of rolled material to 70 ° C or more, shorten the time between multiple cold rolling passes or increase the rolling reduction of one pass. It should be good. When performing multiple cold rolling passes, high-temperature winding can be performed in only one pass.

The aluminum alloy spring material obtained by the method of the present invention described above is further subjected to a chemical conversion treatment or a resin coating treatment of baking at a temperature of 260 ° C. or less. At least one process can be performed. For the chemical conversion treatment, chromate chromate treatment, phosphoric acid chromate treatment and the like are applied.

The resin coating film treatment involves mixing epoxy resin, acrylic resin, vinyl chloride resin, urethane resin paint, or other lubricants such as plastics. This is done by applying a resin paint.

The reason for lowering the baking temperature of the resin coating process to 260 ° C or less is that if it exceeds 260 ° C, the amount of supersaturated solid solution of the alloy element decreases, and the deterioration of the spring force with time cannot be improved. This is because

Hereinafter, the present invention will be described in more detail with reference to Examples.

Example 1

An A1 alloy (No. a to f) having a composition within the range of the present invention shown in Table 1 below was subjected to melting, forging, homogenizing, and hot rolling in order by a conventional method to give a thickness of 4 mm. mm was obtained. Next, the hot-rolled plate was cold-rolled for 3 passes to obtain a cold-rolled plate having a thickness of 1.0 mm. Next, the cold-rolled sheet was heated by a continuous annealing furnace (CAL) to reach a temperature of 500 ° C and an average cooling rate of 800 ° C up to 100 ° C after reaching 500 ° C. Solution treatment and quenching at ° C were performed.

After that, a sheet of 0.40 mm thickness was formed by cold rolling of 2 passes, and the sheet was kept at 60 ° C for 3 hours (natural aging), and then at 120 ° C. Aging treatment is performed for 3 hours to form a spring material. The spring material is press-formed, and a leaf spring 2 having a rising height hi force S14 mm as shown in Fig. 2 is formed. Obtained.

Press molding was performed using a lubricant with a viscosity of 15 cst, but press molding could be performed without any problem. Comparative Example 1

A leaf spring was manufactured by the same method as in Example 1 except that an A1 alloy (No. g to j) out of the composition range of the present invention shown in Table 1 below was used.

With respect to the leaf springs obtained in Example 1 and Comparative Example 1, tensile strength, 0.2% resistance to resistance, elongation, initial set (spring rising height), and deterioration with time of spring force were examined. .

In the initial run, a cycle of loading and unloading a 1 kg weight for 5 seconds was repeated 10 times, and then the rise height of the spring was evaluated for evaluation. When a weight of 1 kg is put on the spring, the spring rises and has a flat shape with a height of O mm.

Deterioration of the spring force over time is measured by measuring the spring force F1 when the spring is pressed down to a height of 2 mm, then placing a 1 kg weight on this spring, and applying the temperature of 70 ° C. After holding at the temperature for 14 days, measure the spring force F 2 by the same method as described above, and substitute it into the equation of P = [(F 1-F 2) / F 1] X 100% Then, P (spring force reduction rate) was obtained and evaluated. If the spring force reduction rate exceeds 20%, it is considered impractical.

The results are shown in Table 2 below. As a conventional example, the characteristics of a 0.3 mm-thick SUS304 leaf spring are also described. table 1

No Mg Si Cu Mn Cr Zr V Sc D i B

1 5 0.50 1.20 0.1 0.01 0.002 lines b 1.8 0.12 0.8 0.1 0.05 0.02 0.01 0.002 departure 1 3 0 14 0.4 0.4 0.03 0.07 0 01 n no? Description un ft o Π 1 0 4 0 R nmn u.η uπu ^. 1.5 0.50 0.40 1.3 0.01 0.002 f 1.5 0.50 0.40 0.01 0.02 Ratio g 2.0 0.1 0.2 0.05 0.01 0.002 Comparison h 0.1 1.1 0.8 0.2 0.05 0.01 0.02 Example i 1.0 0.12 0.4 0.07 0.01 0.002

j having a thickness of 0.3 strokes SUS ³ 04 made of plate spring

Coming

Table 2 Minutes Test Tensile 0.2% Elongation Spring rise Initial stage 14 Spring force Metal strength Strength withstand% Height Spring Spring force drop rate

Να No. MPa Mpa Initial height: 14mm Force gf gf%

1 a 443 421 6.5 10.1mm 221 202 8.5 2b 459 442 6.1 10.3 232 210 9.0

3 c 435 416 6.7 10.1mm 216 197 9.3 Description

4d 388 368 7.8 9.9mm 196 177 9.0 Example

5 470 Q. 10 f mm 238 16 q

6 f 452 433 6.2 10.2mm 231 209 9.5

7 g 477 431 5.9 10.1mm 220 98 55.5 ratio

Comparison 8 h 375 322 6.9 9.0mm 201 91 54.7 Example 9 380 332 8.1 8.5mm 182 75 58.8 Sub 10

J 820 515 9.5 11.2mm 228 219 3.9

As is clear from Table 2 above, all of the samples Nos. 1 to 6 of the present invention have excellent mechanical properties, and have an initial descent (spring rising height) and a spring force. The aging deterioration (spring force reduction rate) is small, and the spring material of the present invention can be replaced with a conventional SUS304 spring material.

On the other hand, since the sample No. 7 of the comparative example did not contain Si, the spring force was significantly deteriorated with time. Sample No. 8 has a low Mg content, and Sample No. 9 does not contain Cu, so that all have low proof stress and a large initial sag. I got it. In addition, the time-dependent deterioration of the spring force was also large.

Example 2

Among the A1 alloys having the composition range of the present invention shown in Table 1 above, alloy No. a was subjected to melting, forging, homogenizing treatment, and hot rolling in order by a conventional method, to obtain a thickness of 4 mm. mm hot-rolled sheet, and this hot-rolled sheet is subjected to a first cold rolling to obtain sheet materials having a thickness of 1.4, 1.0, and 0.4 mm, and these are subjected to various conditions. , And the sheet materials having a thickness of 1.4 and 1.0 mm were further subjected to a second cold rolling to obtain a sheet material having a thickness of 0.4 mm.

In the second cold rolling, the temperature after rolling was set to 70 ° C or more, and the coil was wound on a coil. Further, some of the sheets were subjected to natural aging treatment and aging treatment (the conditions of the present invention), or chemical conversion treatment and resin coating treatment.

The solution treatment conditions are shown in Table 3 below.

Comparative Example 2

In Example 2, the conditions for solution treatment or aging treatment were A spring material was manufactured by the same method as in Example 2, except that the conditions were not outside the invention. The solution treatment conditions are also shown in Table 3 below.

Each spring material having a thickness of 0.4 O mm manufactured according to Example 2 and Comparative Example 2 was held at 60 ° C for 3 days, and then at 120 ° C for 3 hours. Aging treatment was performed, followed by press molding to form a leaf spring 2 having a rising height h1 of 14 mm as shown in FIG.

For each of the obtained leaf springs, the tensile strength, 0.2% resistance to resistance, elongation, initial setting (spring rising height), and deterioration of the spring force with time (spring reduction rate) were measured. The examination was performed in the same manner as in Example 1. The results are shown in Table 4 below.

Table 3

(Note) * Cr: Chromate treatment, U: Urethane resin coating treatment,

P: Phosphoric acid chromate treatment, A: Acrylic resin coating treatment.

Table 4 Minute Test Tensile 0.2% Elongation Press Formability Spring Standing Initial 14 Says Spring Material Strength Cage Resistance Spring Decreased

No. No. Pa MPa% Lubricant

Class height Power gf Power gf rate 96

11 a 389 356 6.8 15cst None 9.6 188 175 6.9

12 a 399 369 7.3 No lubrication None 9.5 195 180 7.7 pcs

13

Departure a 440 430 6.1 15cst None 9.9 218 204 6.4 Description 14 a 455 443 5.5 Volatile oil None 10.6 222 199 10.4 Example

15 a 383 291 14.1 15cst None 9.1 185 174 5.9

16 a 382 244 16.9 15cst None 8.9 179 168 6.1 Ratio 17 a 342 215 18.8 15cst None 8.5 178 94 47.2 Compare

An example

18 a 412 309 17.5 15cst None 9.0 185 129 30.3

As is evident from Table 4 above, all of the samples Nos. 11 to 16 of the present invention have excellent mechanical properties and have an initial height (bump height). The deterioration of the spring force with time (spring reduction rate) was small, and there was no practical problem. As a result, it has been found that the spring material of the present invention can be replaced with a conventional SUS304 spring material.

Furthermore, it was demonstrated that good formability was obtained even when volatile oil was used as the lubricating oil, and that the washing step could be omitted.

In particular, for sample No. 14, the initial aging treatment was remarkably improved because the proper aging treatment including coil aging treatment was performed twice. Samples Nos. 15 and 16 did not cold-roll after the solution treatment, so their proof stress was low and the initial sag was slightly larger. It has become extremely small.

On the other hand, in Sample No. 17 of the comparative example, the cooling rate after the solution treatment was slow, and in Sample No. 18, the aging treatment temperature was high. The spring force decreased significantly and deteriorated with time. In addition, sample No. 17 had a low initial strength, and thus had a large initial descent.

As described above, according to the present invention, it is possible to obtain an aluminum alloy spring material in which the initial deterioration and the deterioration with time of the spring force are improved. The aluminum alloy spring material is suitable for use as a leaf spring for preventing the reel from spinning on a magnetic tape cassette, and the spring material of the present invention is formed by a conventional method. However, by defining the conditions, it can be easily manufactured. Therefore, the present invention has a significant industrial effect.

Claims

The scope of the claims

2.0 weight at 1.0 0.3 weight% or more. /. Less than Mg, 0.1-1.5% by weight Si, and 0.1-3.0% by weight. /. An aluminum alloy spring material containing the following Cu, the balance being A 1 and unavoidable impurities.

2.0 .01 to 1.5 weight. 2. The aluminum alloy spring material according to claim 1, further comprising Mn of / ₀ .

3.0.01 to 0.5 weight. /. Cr, 0.01 to 0.2 weight. /. Zr, 0.01 to 0.2 weight. /. V, 0.01-0.2 weight. /. Sc, 0.001 to 0.2 weight. /. T i, and 0.0001 to 0.05 weight. The aluminum alloy spring material according to claim 2, further comprising at least one member selected from the group consisting of a B force of / ₀ .

4. Content of Mg 0.6-: 1.8 weight. The aluminum alloy spring material according to claim 3, wherein the ratio is / ₀ .

5. The aluminum alloy spring material according to claim 3, wherein the content of Cu is 0.4 to 2.0% by weight.

4. The aluminum alloy spring material according to claim 3, wherein the 60.2% proof stress exceeds 300 MPa and is less than 450 MPa.

7. The aluminum alloy spring material according to claim 3, wherein a chemical conversion coating, a resin coating, or both a chemical conversion coating and a resin coating are formed on the surface. .

8. The aluminum alloy spring material according to claim 7, wherein the thickness of the chemical conversion film, the resin film, or both the chemical conversion film and the resin film is 1 O / zm or less.

9. A leaf spring for a magnetic recording tape cassette, comprising the aluminum alloy spring material according to claim 3.

10. A magnetic recording tape cassette comprising: a pair of reels on which a magnetic recording tape is wound; and the leaf spring according to claim 9 attached to these reels.

2.0 weight when 10.3 weight% or more. /. Less than Mg, 0.1 to: 1.5 weight. /. S i, and 0:! ~ 3.0 weight. /. A solution treatment of an aluminum alloy plate containing Cu of the remainder, and comprising the remainder A1 and unavoidable impurities, at a temperature of 400 to 550 ° C.

A step of cooling the solution-treated aluminum alloy plate to a temperature of 100 ° C or less at a cooling rate of 100 ° C or more, and

A method for producing an aluminum alloy spring material, comprising a step of cold rolling the cooled aluminum alloy plate.

. 1 2 The Anore mini © beam alloy sheet, 0 0 1 ~:.. 1 according to 5 weight ⁰ / claim 1 1, further free of M n of ₀ Aluminum two U of arm alloy spring member Production method.

13. The said aluminum alloy plate is composed of 0.01 to 0.5% by weight of Cr, 0.01 to 0.2% by weight of Zr, and 0.01 to 0.2% by weight. . /. V, 0.01-0.2 weight. /. Sc, 0.001 to 0.2% by weight of D, 1, 0.001 to 0.05% by weight. The method for producing an aluminum alloy spring material according to claim 12, further comprising at least one member selected from the group consisting of B / ₀ and B / ₀ .

14. The cold-rolled aluminum alloy sheet is 80 ~ 1 14. The method for producing an aluminum alloy spring material according to claim 13, further comprising a step of performing an aging treatment of heating at a temperature of 80 ° C for 1 hour to less than 10 hours.

15. The cold rolling step is performed under the condition that the surface temperature of the rolled material after the cold rolling is 70 ° C. or more, and the rolled material after the cold rolling is cored. 14. The method for producing an aluminum alloy spring material according to claim 13, further comprising a step of winding into an coil.

16. The method further comprises a step of subjecting the rolled material after the cold rolling to at least one of a chemical conversion treatment and a resin coating treatment of baking at a temperature of 260 ° C. or less. A method for producing the aluminum alloy spring material according to claim 13.

17. The aluminum alloy spring according to claim 13, further comprising a natural aging step of maintaining the temperature at 30 to 70 ° C for 1 hour or more before the aging step. The method of manufacturing the material.