JP2020033607A - Al-Mg-Si-BASED ALLOY SHEET - Google Patents

Abstract

To provide an Al-Mg-Si-based alloy sheet having high conductivity and high strength.SOLUTION: There is provided an Al-Mg-Si-based alloy sheet having a fiber structure with a chemical composition containing Si:0.2 to 0.8 mass%, Mg:0.3 to 1 mass%, Fe:0.5 mass% or less, and Cu:0.5 mass% or less, and further containing at least one kind of Ti:0.1 mass% or less or B:0.1 mass% or less, and the balance Al with inevitable impurities, tensile strength of 170 MPa or more, a value obtained by dividing 0.2% yield strength (MPa) by the tensile strength (MPa) of 0.91 to 1.00, conductivity of 50%<conductivity<54% (IACS), and sheet thickness of 3 mm≤sheet thickness≤9 mm.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an Al—Mg—Si alloy plate, particularly to an Al—Mg—Si alloy plate having excellent thermal conductivity, conductivity, and strength.

  Heating elements such as chassis, metal base printed circuit boards, and inner covers for products such as flat-screen TVs, thin monitors for personal computers, notebook computers, tablet computers, car navigation systems, portable navigation systems, and mobile terminals such as smartphones and mobile phones The material of the member to be incorporated or mounted is required to have excellent thermal conductivity, strength and workability for quickly dissipating heat.

  Pure aluminum alloys such as JIS1100, 1050, and 1070 have excellent thermal conductivity but low strength. An Al-Mg alloy (5000-based alloy) such as JIS5052 used as a high-strength material has significantly lower thermal conductivity and conductivity than a pure aluminum-based alloy.

  On the other hand, an Al-Mg-Si alloy (6000 alloy) has good thermal conductivity and conductivity and can improve strength by age hardening. A method for obtaining an aluminum alloy plate having excellent conductivity and workability has been studied.

  For example, Patent Document 1 contains 0.1 to 0.34% by mass of Mg, 0.2 to 0.8% by mass of Si, and 0.22 to 1.0% by mass of Cu, with the balance being Al and An alloy composed of unavoidable impurities and having a Si / Mg content ratio of 1.3 or more is formed into an ingot having a thickness of 250 mm or more by semi-continuous casting, and is subjected to pre-heating at a temperature of 400 to 540 ° C and hot rolling. A method of manufacturing a rolled sheet is disclosed in which cold rolling is performed at a rolling reduction of ８５85%, and then annealing is performed at a temperature of 140 to 280 ° C.

  Patent Document 2 contains Si: 0.2 to 1.5% by mass, Mg: 0.2 to 1.5% by mass, and Fe: 0.3% by mass or less. 0.15% by mass, Cr: one or two of 0.02 to 0.15%, and the balance is restricted to 0.2% or less of Al and Ti in inevitable impurities, or An aluminum alloy plate having a composition containing one or two of Cu: 0.01 to 1% by mass or rare earth element: 0.01 to 0.2% by mass is produced by continuous casting and rolling, and then cold-rolled. Then, a solution treatment at 500 to 570 ° C. is performed, followed by a cold rolling at a cold rolling reduction of 5 to 40%, and an aging treatment of heating at 150 to less than 190 ° C. after the cold rolling. Aluminum alloy plate with excellent thermal conductivity, strength and bending workability It describes the preparation method.

  Patent Document 3 discloses a heat-dissipating member manufactured by homogenizing an Al-Mg-Si-based alloy ingot, performing hot rough rolling and hot finish rolling, and then processing a cold-rolled alloy plate into a required shape. Containing 0.2 to 0.8 wt% of Si, 0.3 to 0.9 wt% of Mg, 0.35 wt% or less of Fe, and 0.20 wt% or less of Cu, with the balance being Al and unavoidable impurities. An aluminum heat dissipating member comprising:

  In the case of the Al-Mg-Si alloy, the thermal conductivity and the electrical conductivity show a good correlation, and the aluminum alloy plate having the excellent thermal conductivity has the excellent electrical conductivity. It can be used as a conductive member material.

JP 2012-62517 A JP 2007-9262 A JP 2000-226628 A

  Workability is affected by the relationship between tensile strength and proof stress. If the proof stress is lower than the tensile strength, work hardening occurs, and in the case of multi-stage molding, the workability is reduced. The workability also changes depending on the metal structure of the Al-Mg-Si alloy sheet.

  However, in Patent Document 1, the study of the process conditions is insufficient, and the yield strength is not studied. Further, in Patent Document 1, the tensile strength is improved by the contribution of Si or Cu, and the element next to Al is Si or Cu, the content of Mg is relatively small, and Si and Mg Are not included in the claims of Patent Document 1. Further, the description of the properties and thickness of the plate material is not in the claims of Patent Document 1.

  In Patent Document 2, although a relatively high strength is obtained, the conductivity described in Examples is low.

  In Patent Document 3, the invention 1 described in Examples has a small difference in tensile strength and proof stress, but low thermal conductivity, and the invention 2 has a higher thermal conductivity than the invention 1 but has a low tensile strength and proof stress. The difference is greater than Invention 1.

  Further, Patent Documents 2 and 3 do not describe the metal structure of the obtained Al—Mg—Si alloy plate.

  As described above, in Patent Literatures 1 to 3, it is very difficult to obtain an Al-Mg-Si-based alloy plate having high electrical conductivity, which is close to the values of tensile strength and proof stress.

  In view of the technical background described above, the present invention has a high value obtained by dividing 0.2% proof stress (MPa) by tensile strength (MPa), and has high conductivity and high strength. The purpose is to provide.

The above problem is solved by the following means.
(1) The chemical composition contains Si: 0.2 to 0.8% by mass, Mg: 0.3 to 1% by mass, Fe: 0.5% by mass or less, and Cu: 0.5% by mass or less, Further, it contains at least one kind of Ti: 0.1% by mass or less or B: 0.1% by mass or less, the balance is composed of Al and unavoidable impurities, the tensile strength is 170 MPa or more, and the 0.2% proof stress (MPa) ) Divided by the tensile strength (MPa) is 0.91 or more and 1.00 or less, the electrical conductivity is 50% <the electrical conductivity <54% (IACS), and the thickness is 3 mm ≦ the thickness ≦ 9 mm. An Al-Mg-Si alloy plate having:
(2) The Al-Mg-Si alloy plate according to the above item 1, wherein Mn, Cr, and Zn as impurities are each regulated to 0.1% by mass or less.
(3) The Al-Mg-Si alloy material according to the above item 1 or 2, wherein Ni, V, Ga, Pb, Sn, Bi and Zr as impurities are each regulated to 0.05% by mass or less.
(4) The Al-Mg-Si alloy plate according to any one of the above items 1 to 3, wherein Ag as an impurity is regulated to 0.05% by mass or less.
(5) The Al-Mg-Si alloy plate according to any one of the above items 1 to 4, wherein the total content of rare earth elements as impurities is regulated to 0.1% by mass or less.

  According to the invention described in the above item (1), the chemical composition is as follows: Si: 0.2 to 0.8% by mass, Mg: 0.3 to 1% by mass, Fe: 0.5% by mass or less, and Cu: 0%. 0.5% by mass or less, and further contains at least one kind of Ti: 0.1% by mass or less or B: 0.1% by mass or less, the balance being Al and unavoidable impurities. .2% yield strength (MPa) divided by tensile strength (MPa) is large, and an Al—Mg—Si alloy plate having a fiber structure with high conductivity and a thickness of 3 mm ≦ plate thickness ≦ 9 mm can be formed. .

  According to the invention described in the above item (2), since Mn, Cr, and Zn as impurities are each regulated to 0.1% by mass or less, the tensile strength is high and the 0.2% proof stress (MPa) ) By the tensile strength (MPa) is large, and an Al—Mg—Si alloy plate having a fiber structure with high conductivity can be obtained.

  According to the invention described in the above item (3), Ni, V, Ga, Pb, Sn, Bi, and Zr as impurities are each regulated to 0.05% by mass or less. A value obtained by dividing 0.2% proof stress (MPa) by tensile strength (MPa) is large, and an Al-Mg-Si alloy plate having a fiber structure with high conductivity can be obtained.

  According to the invention described in the above item (4), Ag as an impurity is regulated to 0.05% by mass or less, so that the tensile strength is strong, and the 0.2% proof stress (MPa) is changed to the tensile strength (MPa). ), The Al—Mg—Si alloy plate having a fiber structure with high conductivity can be obtained.

  According to the invention described in the above item (5), since the total content of the rare earth elements as impurities is regulated to 0.1% by mass or less, the tensile strength is strong and the 0.2% proof stress (MPa) is reduced. An Al-Mg-Si-based alloy plate having a large value divided by the tensile strength (MPa) and having a fiber structure with high conductivity can be obtained.

It is a model figure of the fiber structure of the Al-Mg-Si type alloy plate of this application.

  The inventor of the present application has set the surface temperature of a hot-rolled alloy sheet to a predetermined temperature or less in a method for producing an Al-Mg-Si alloy sheet in which hot rolling and cold rolling are sequentially performed. The present invention was found that a value obtained by dividing the .2% proof stress (MPa) by the tensile strength (MPa) was large, and an Al—Mg—Si alloy plate having high conductivity and high strength was obtained.

  Hereinafter, the Al-Mg-Si-based alloy plate of the present application will be described in detail.

  In the composition of the Al-Mg-Si alloy plate of the present invention, the purpose of addition of each element and the reason for limiting the content are as follows.

  Mg and Si are elements necessary for the development of strength, and the content of each is set to 0.2% by mass to 0.8% by mass of Si, and 0.3% by mass to 1% by mass of Mg. If the Si content is less than 0.2% by mass or the Mg content is less than 0.3% by mass, sufficient strength cannot be obtained. On the other hand, when the Si content exceeds 0.8% by mass and the Mg content exceeds 1% by mass, the rolling load in hot rolling increases, the productivity decreases, and the formability of the obtained aluminum plate is poor. Become. The Si content is preferably from 0.2% by mass to 0.6% by mass, more preferably from 0.32% by mass to 0.60% by mass. The Mg content is preferably from 0.45 mass% to 0.9 mass%, more preferably from 0.45 mass% to 0.55 mass%.

  Fe and Cu are necessary components for molding, but if they are contained in large amounts, the corrosion resistance is reduced. In the present application, the Fe content and the Cu content are each regulated to 0.5% by mass or less. The Fe content is preferably regulated to 0.35% by mass or less, and more preferably 0.1% to 0.25% by mass. The Cu content is preferably 0.1% by mass or less.

  Ti and B are effective in reducing crystal grains and preventing solidification cracking when casting an alloy into a slab. The above effect is obtained by adding at least one of Ti and B, and both may be added. However, when contained in a large amount, a large amount of crystallized matter is generated, so that the processability, thermal conductivity and electrical conductivity of the product are reduced. The Ti content is preferably 0.1% by mass or less, more preferably 0.005% by mass or more and 0.05% by mass or less. Further, the B content is preferably 0.1% by mass or less, and particularly preferably 0.06% by mass or less.

  In addition, various impurity elements are inevitably contained in the alloy element, but Mn and Cr decrease the conductivity and conductivity, and when the content of Zn is increased, the corrosion resistance of the alloy material is reduced. preferable. The content of each of Mn, Cr, and Zn as impurities is preferably 0.1% by mass or less, and more preferably 0.05% by mass or less.

  Other impurity elements other than the above include Ni, V, Ga, Pb, Sn, Bi, Zr, Ag, rare earths, and the like, but are not limited thereto. Other than the above, the content of each element is preferably 0.05% by mass or less. Among the other impurity elements, the rare earth element may contain one or more kinds of elements, and may be derived from a casting raw material contained in a misch metal state. The amount is preferably 0.1% by mass or less, more preferably 0.05% by mass or less.

  Next, processing steps for obtaining the Al-Mg-Si alloy plate specified in the present application will be described.

  The melting component is adjusted by a conventional method to obtain an Al-Mg-Si alloy ingot. It is preferable to apply a homogenization treatment to the obtained alloy ingot as a step before heating before hot rolling.

  The homogenization treatment is preferably performed at 500 ° C. or higher.

  The heating before the hot rolling is performed in order to form a uniform structure by dissolving the crystallized material, Mg, and Si in the Al-Mg-Si alloy ingot, but if the temperature is too high, eutectic melting occurs. Therefore, the heat treatment is preferably performed at 450 ° C. to 580 ° C., particularly preferably at 500 ° C. to 580 ° C.

  After performing the homogenization treatment on the Al-Mg-Si-based alloy ingot, the ingot may be cooled and subjected to heating before hot rolling, or the homogenization treatment and the heating before hot rolling may be continuously performed, In the preferred temperature range of the homogenization treatment and the heating before hot rolling, heating may be performed at the same temperature as both the homogenization treatment and the heating before hot rolling.

  After casting, before hot rolling and before heating, it is preferable to subject the ingot to face milling in order to remove an impurity layer near the surface of the ingot. The facing may be performed after the casting and before the homogenization treatment, or may be performed after the homogenization treatment and before the hot rolling and the heating.

  The hot-rolled Al-Mg-Si alloy ingot is subjected to hot rolling before heating.

  Hot rolling consists of rough hot rolling and finish hot rolling, and after performing rough hot rolling consisting of multiple passes using a rough hot rolling mill, a finishing hot rolling mill different from the rough hot rolling mill. And finish hot rolling is performed. In the present application, when the final pass in the rough hot rolling mill is the final pass of hot rolling, finish hot rolling can be omitted.

  In the present application, the finish hot rolling is performed by introducing an Al-Mg-Si-based alloy material from one direction using a rolling mill in which one set of upper and lower work rolls or two or more sets of work rolls are continuously installed. Will be implemented in the pass.

  When performing cold rolling with a coil, the Al—Mg—Si alloy material after the finish hot rolling may be wound by a winding device to form a hot rolled coil. When finishing hot rolling is omitted and the final pass of rough hot rolling is the final pass of hot rolling, after the rough hot rolling, the Al-Mg-Si alloy material is wound by a winding device. It may be a hot-rolled coil.

  In the rough hot rolling, after maintaining the solid solution of Mg and Si according to the solution treatment, cooling of the Al-Mg-Si alloy material by the course of the rough hot rolling or the rough hot rolling. The effect of quenching can be obtained by the temperature drop by the pass and the forced cooling after the pass.

  In the present application, among the plurality of passes of the rough hot rolling, the surface temperature of the Al-Mg-Si alloy material immediately before the pass is 350 ° C or more and 470 ° C or less, and the Al-Mg-Si alloy material is cooled by the pass or the pass is cooled. A path in which the average cooling rate by forced cooling after the pass is 50 ° C./min or more is referred to as a control path. The reason that the surface temperature of the Al—Mg—Si alloy material immediately before the control pass is 350 ° C. or more and 470 ° C. or less is that when it is less than 350 ° C., the effect of quenching by rapid cooling in rough hot rolling is small, and the temperature is higher than 470 ° C. This is because it is difficult to rapidly cool the Al-Mg-Si-based alloy material rising in the pass.

  The average cooling rate is an Al-Mg-Si alloy from the start to the end of the control pass when the forced cooling is not performed in the control pass, and from the start to the end of the forced cooling when the forced cooling is performed after the control pass. It is the value obtained by dividing the temperature drop (° C) of the material by the required time (minutes).

  The forced cooling after the control pass may be performed sequentially on the rolled portion while rolling the Al-Mg-Si alloy material, or may be performed after rolling the entire Al-Mg-Si alloy material. Is also good. The method of forced cooling is not limited, but may be water cooling, air cooling, or use of a coolant.

  The control pass is preferably performed at least once, and may be performed a plurality of times. When a control pass is performed a plurality of times, it is possible to select whether or not to perform forced cooling after each pass. If the surface temperature of the Al-Mg-Si alloy material immediately before the pass is 470 to 350 ° C and the cooling rate is 50 ° C / min or more, the control pass can be performed a plurality of times, but with one control pass. By lowering the temperature of the Al-Mg-Si alloy material to less than 350 ° C, quenching can be performed efficiently and effectively.

  In the present application, when the forced cooling is not performed after the final pass of the rough hot rolling, the surface temperature of the Al-Mg-Si alloy material immediately after the final pass of the hot rolling is defined as the rough hot rolling rising temperature, When the forced cooling is performed after the final pass of the rolling, the surface temperature of the Al-Mg-Si alloy material immediately after the completion of the forced cooling is set as the rough hot rolling rising temperature.

  If the finish hot rolling is performed in the present application, the finish hot rolling is completed, and if the finish hot rolling is not performed, the end of the final pass of the rough hot rolling is regarded as the end of the hot rolling, and immediately after the end of the hot rolling. It is preferable that the surface temperature of the Al—Mg—Si alloy material is 170 ° C. or less.

  By setting the temperature of the alloy material immediately after hot rolling to 170 ° C. or less, an effective quenching effect can be obtained.

  If the surface temperature of the Al-Mg-Si alloy material immediately after the completion of hot rolling is too high, the effect of quenching is insufficient, and the strength is improved even if heat treatment is performed after completion of hot rolling and before completion of cold rolling. Becomes insufficient. The surface temperature of the aluminum plate immediately after the completion of the hot rolling is more preferably 150 ° C or lower, and particularly preferably 130 ° C or lower.

  In the case of performing the finish hot rolling after the rough hot rolling, in order to obtain a quenching effect by the pass of the finish hot rolling, the surface temperature of the Al-Mg-Si based alloy plate immediately before the finish hot rolling is The temperature is preferably 280 ° C. or lower.

  Similarly, when the final pass of the rough hot rolling is not the control pass without performing the finish hot rolling, the surface temperature of the Al—Mg—Si alloy sheet immediately before the final pass of the rough hot rolling is 280 ° C. or less. preferable.

  On the other hand, when the final pass of the rough hot rolling is the control pass without performing the finish hot rolling, the control pass is the final pass of the hot rolling, so the Al-Mg-Si system immediately before the final pass of the hot rolling is used. A control pass is performed so that the surface temperature of the alloy sheet is 470 to 350 ° C and the surface temperature of the alloy sheet is 170 ° C or less at a cooling rate of 50 ° C / min or more by rolling or forced cooling after rolling and rolling. Is preferred.

  The production of the Al—Mg—Si alloy material of the present application may be performed using a coil or a single plate.

  According to the above-described manufacturing method, an Al-Mg-Si-based alloy plate having improved strength while maintaining high conductivity can be obtained.

  The Al-Mg-Si alloy material of the present application has a fiber structure. The fiber structure is a metal structure elongated by plastic working.

  FIG. 1 shows a model diagram of the fiber structure of the Al—Mg—Si alloy plate of the present invention.

  As shown in FIG. 1, in the present application, the metal structure is exposed such that the normal line of the observation surface is perpendicular to both the processing direction vector of the Al—Mg—Si alloy plate and the normal direction vector of the processing surface. A metal structure having a grain boundary in the normal direction of the working surface of the metal structure on the observation surface observed by an optical microscope of 3 grains / 100 μm or more and a grain boundary having a length of 300 μm or more in the working direction is defined as a fiber structure. . In the case where the plastic working is rolling, the working direction is the rolling direction, the working surface is a rolled surface, and the observation surface is a cross section in the thickness direction cut parallel to the rolling direction.

  As a method of exposing the metal structure, the surface of the Al-Mg-Si alloy material whose normal is perpendicular to both the processing direction vector of the Al-Mg-Si alloy material and the normal direction vector of the processed surface is polished. After that, a method of anodizing the polished surface can be exemplified. As the anodizing solution, Barker's solution (3% aqueous borofluoric acid solution) can be suitably used.

  The conductivity of the Al—Mg—Si alloy plate of the present application is specified as 50% <conductivity <54% (IACS), the plate thickness is 3 mm ≦ the plate thickness ≦ 9 mm, and the tensile strength is 170 MPa or more. The value obtained by dividing the 0.2% proof stress (MPa) of the Al-Mg-Si alloy material of the present application by the tensile strength (MPa) is specified to be 0.91 or more and 1.00 or less. An Al—Mg—Si alloy sheet having a fiber structure that satisfies the value obtained by dividing the 0.2% proof stress (MPa) by the tensile strength (MPa) and the tensile strength specified in the present application is obtained. The value obtained by dividing the 0.2% proof stress (MPa) by the tensile strength (MPa) is more preferably 0.92 or more and 1.00 or less, particularly preferably 0.93 or more and 1.00 or less.

  Hereinafter, examples and comparative examples of the present invention will be described.

Aluminum alloy slabs having different chemical compositions shown in Table 1 were obtained by DC casting. In addition, for the ingot of chemical composition No. 20 containing rare earth, a raw material containing misch metal was used for casting.
[Example 1]
The aluminum alloy slab having the chemical composition No. 1 in Table 1 was subjected to facing. Next, the alloy slab after the face milling was subjected to a homogenization treatment at 570 ° C. for 3 hours in a heating furnace, and then the temperature was changed in the same furnace to perform pre-heating at 540 ° C. for 4 hours before hot rolling. After heating before hot rolling, the slab at 540 ° C. was taken out of the heating furnace, and rough hot rolling was started. After the thickness of the alloy sheet during the rough hot rolling becomes 25 mm, the final pass of the rough hot rolling is performed at an average cooling rate of 80 ° C./min from an alloy sheet temperature of 451 ° C. immediately before the pass, and An alloy plate having a thickness of 12 mm was formed at a temperature of 222 ° C. after the hot rolling. In the final pass of the rough hot rolling, the alloy plate was moved while being rolled, and forced cooling was performed by water cooling in which water was sprayed onto the alloy plate sequentially from above and below the rolled alloy plate.

  After the rough hot rolling, the alloy sheet was subjected to finish hot rolling from a temperature immediately before the finish hot rolling of 220 ° C. to obtain an alloy sheet having a thickness of 7.0 mm. The temperature of the alloy sheet immediately after the finish hot rolling was 111 ° C.

[Examples 2 to 32, Comparative Examples 1 to 6]
After subjecting the aluminum alloy slab shown in Table 1 to beveling, treatment was performed under the conditions shown in Tables 2 to 5 to obtain an aluminum alloy plate. In all the examples and comparative examples, the homogenization treatment and the heating before hot rolling were continuously performed in the same furnace as in Example 1, and the forced cooling after the final pass of the rough hot rolling was performed while rolling. Either water cooling, in which the alloy sheet was moved and water was sprayed onto the alloy sheet sequentially from above and below the alloy sheet after rolling, or air cooling, in which blast cooling was performed after completion of the final pass of the rough hot rolling, was selected.

  In Example 18, the final pass of the rough hot rolling was the final pass of the hot rolling, and the finishing hot rolling was not performed.

  In Comparative Examples 1 and 2, a solution treatment was performed in which a heat treatment was performed at 550 ° C. for 1 minute during cold rolling and then cooled at a rate of 5 ° C./sec or more. In Comparative Example 1 and Comparative Example 2, the cold rolling reduction is the total rolling reduction of the cold rolling before and after the solution treatment, and the cold rolling after the solution treatment is based on the thickness of the alloy material after the solution treatment. Was carried out so that the cold-rolling ratio of the sample was 30%.

  The tensile strength, 0.2% proof stress, electrical conductivity, and whether or not the obtained alloy sheet had a fiber structure were evaluated by the following methods.

  The tensile strength and 0.2% proof stress of a JIS No. 5 test piece were measured at room temperature by a conventional method.

The electrical conductivity was determined as a relative value (% IACS) when the electrical conductivity of annealed standard annealed copper (volume low efficiency 1.7241 × 10 ^-2 μΩm) adopted internationally was taken as 100% IACS.

  In Examples and Comparative Examples, when exposing a metal structure of a cross section of an Al-Mg-Si based alloy plate in a thickness direction cut in parallel to a rolling direction, a normal to a rolling surface of the metal structure observed by an optical microscope The metal structure in which the number of grain boundaries in the direction was 3/100 μm or more and the length of the rolling direction was 300 μm or more was defined as a fiber structure.

  As a method of exposing the metal structure, a cross section of an Al-Mg-Si alloy plate cut in parallel to the rolling direction is polished with emery paper, subjected to rough buff polishing and finish polishing, and then washed with water and dried. Further, a method of performing anodizing treatment in Barker's solution (3% aqueous borofluoric acid solution) at a bath temperature of 28 ° C., an applied voltage of 30 V, and an applied time of 90 seconds was applied.

  The tensile strength, 0.2% proof stress, the value obtained by dividing the 0.2% proof stress (MPa) by the tensile strength (MPa), the evaluation results of the electrical conductivity and workability, and the Al-Mg-Si based alloy plate Tables 6 and 7 show whether or not they have a fiber structure.

  Each of the examples satisfies the chemical composition, tensile strength, value obtained by dividing 0.2% proof stress (MPa) by tensile strength (MPa), electrical conductivity, and plate thickness, and the fiber structure of each of the Examples Al-Mg-Si alloy plate with good workability. On the other hand, Comparative Examples 1 and 2 in which the solution treatment was performed during the cold rolling had no fiber structure and conductivity was inferior to those of Examples, and Comparative Examples 3 to 3 in which the chemical composition did not satisfy the range specified in the present application. In Example 6, at least one of the tensile strength and the electrical conductivity is inferior to the examples, and some of them are inferior in workability.

Claims (5)

  The chemical composition contains Si: 0.2 to 0.8% by mass, Mg: 0.3 to 1% by mass, Fe: 0.5% by mass or less, and Cu: 0.5% by mass or less. 0.1% by mass or less: B: At least one kind of 0.1% by mass or less, the balance consisting of Al and unavoidable impurities, tensile strength of 170 MPa or more, and 0.2% proof stress (MPa) Al having a fiber structure in which the value divided by the strength (MPa) is 0.91 or more and 1.00 or less, the conductivity is 50% <the conductivity <54% (IACS), and the plate thickness is 3 mm ≦ the plate thickness ≦ 9 mm. -Mg-Si based alloy plate.   The Al-Mg-Si alloy plate according to claim 1, wherein Mn, Cr, and Zn as impurities are each regulated to 0.1 mass% or less.   The Al-Mg-Si alloy plate according to claim 1 or 2, wherein Ni, V, Ga, Pb, Sn, Bi and Zr as impurities are each regulated to 0.05% by mass or less.   The Al-Mg-Si alloy plate according to any one of claims 1 to 3, wherein Ag as an impurity is regulated to 0.05% by mass or less.   The Al-Mg-Si alloy plate according to any one of claims 1 to 4, wherein the total content of rare earth elements as impurities is regulated to 0.1% by mass or less.

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