TW201242141A - Aluminum alloy sheet for battery case having good moldability and weldability - Google Patents

Abstract

The present invention provides an Al-Fe based aluminum alloy sheet having sufficiently high strength for application as a large lithium-ion battery container, as well as good moldability and good laser weldability. The cold-rolled aluminum alloy sheet has an elongation of 2% or more and tensile strength of 160 MPa or more, and has: a chemical composition comprising 0.3 to 1.5 mass% Fe, 0.3 to 1.0 mass% Mn, 0.2 to 1.0 mass% Cu, 0.2 to 1.0 mass% Mg, 0.002 to 0.20 mass% Ti, and 0.05 to 0.20 mass% Zr, with an Mn/Fe mass ratio of 0.2 to 1.0, and the remainder comprising Al and inevitable impurities, such inevitable impurities comprising less than 0.30 mass% Si; and a metallographic structure in which the number of second-phase particles with an equivalent circle diameter of 5 μ m or more is less than 500/mm2. Alternatively, the aluminum alloy sheet is a cold-rolled annealed material having an elongation of 20% or more and tensile strength of 130 MPa or more.

Description

201242141 VI. Description of the Invention: The invention relates to a high-strength aluminum alloy excellent in formability and laser weldability of a container for a secondary battery used in a lithium ion battery or the like. board. Background of the Invention Since the A1 - Μ 的 3 000 series alloy is excellent in strength, formability, and laser fusion property, it is used as a material for manufacturing a secondary battery container such as a lithium ion battery, and is formed into a desired shape. After the shape, the seal is sealed by laser welding and used as a container for a secondary battery. Further, there has been developed an aluminum alloy sheet for a secondary battery container which further improves the strength and formability by using the above-described 3000 series alloy and an existing three-bismuth alloy as a base. For example, in the patent publication No. 4001007, a metal alloy plate for a rectangular cross-section battery container is characterized in that the composition of the aluminum alloy plate contains: Si: 0.10 to 0.60% by mass, Fe: 0.20 to 0.60% by mass, Cu : 〇.1〇~0.70 Mass 〇/〇, Μη: 0.60~1.50% by mass, Mg: 0.20~1.20% by mass, Zr: more than 0.12 and less than 20.20% by mass, Ti: 〇〇5~〇25 mass %, and B: 0.0010~〇_〇2 quality. /. The remainder is composed of gossip and unavoidable impurities' and in the deep extension forming method of the cylindrical container, the 45-ear ratio with respect to the rolling direction is 4 to 7%. On the other hand, 'a lithium-ion battery with sufficient strength, extension-shrinkage processability, and creep characteristics as a battery case, and excellent in laser fusion properties to suppress an increase in the thickness of the case during charge and discharge cycles has recently been developed. 201242141 Aluminum alloy plate for outer casing. Japanese Laid-Open Patent Publication No. 2010-126804 discloses an aluminum alloy plate for a prismatic battery container, which contains Μη: 0.8% by mass or more and 1.8% by mass/. Hereinafter, Mg: more than 〇6 mass% and 1.2 mass% or less, and Cu: more than 0.5 mass% and 丨5 mass. /. Hereinafter, Fe as an impurity is limited to 0.5 mass. /〇 below and Si is limited to 〇3 mass% or less, and the remaining portion has a composition composed of A1 and unavoidable impurities, and a ratio of azimuthal density S of azimuth density orientation of {001}<100> azimuth (C/S) is 0.65 or more and 1.5 or less, and further, the tensile strength after the final cold rolling is 25 MPa MPa or more and 330 MPa or less, and the elongation is 1% or more. However, in the aluminum alloy plate whose composition is improved by using a 3 lanthanum alloy as a base, there is also a problem that the fusion fusion depth is insufficient, and an abnormal weld bead may be generated in the case of laser fusion. something wrong. In view of this, there has also been developed an aluminum alloy sheet for a human battery container which is based on the 丨000 series and which is excellent in laser welding properties. In Japanese Laid-Open Patent Publication No. 2009-127075, there is a 33-type alloy material for a pulsed laser welding and a battery casing, which can be used to prevent the occurrence of an abnormal portion and uniformly form a good (10) connection by means of a pulsed lightning (four). According to this content, it is conventionally known that the addition of ruthenium for suppressing the coarsening of crystal grains during the scale formation causes a defect to the welded portion. Therefore, in order to prevent the A1 from being spliced by pulsed laser welding, In the formation of the abnormal portion when the aluminum is melted, it is only necessary to limit the Ti contained in the pure money to less than 0.01% by mass. In addition, as a base based on a 3_ series alloy, it has been improved in high strength, forming r and refining! Lu alloy, which has been recorded in the special opening 3·7 application bulletin 201242141, contains Mn:G.3~mass over ι() and to i8 mass%, and remains. The boring tool is a secondary battery case composed of A1 and unavoidable impurities. The Lvkou gold plate may also contain Cu: 〇"~〇"% and/or Mg: exceeds l-〇fs% A/^Qr. 〇 -〇5~〇.2f 4〇/oA/^Zr: 0.05^0.2% by weight. However, there is no detailed review of the splicing. In the case of the 1GGG towel, the material stability is stable (the number of abnormal beads is small). The shape is excellent. However, the problem is low, and the strength is low. The requirements for strength characteristics, therefore, direct application of 1000 series aluminum will have problems. As shown in the figure, in the 3000-series alloy sheet, strength and depth are obtained. Compared with the 1000-series alloy sheet, the moldability is poor and the number of bead balls tends to be large. Further, in the alloy sheet of the i-cut type, the edge is excellent and the number of abnormal beads is lowered, but there is a problem that the strength is insufficient. The present invention has been made to solve the above-mentioned problems, and an object thereof is to provide an A1m alloy sheet which is excellent in high strength, excellent in formability, and excellent in laser turnability, which is applicable to a large-sized lithium ion battery container. In order to achieve the object of the present invention, the electric alloy/external alloy sheet which is excellent in formability and weldability of the present invention is characterized in that it has the following chemical composition and a circular equivalent 彳 two lengths of 5 μm or more and a low number of second phase particles. The chemical composition of the metal structure at 5 / / rmn 2 is: containing Fe: 0.3 to 1.5% by mass, and Mn: 0.3-1.0 temporarily 〇 / 里. , Cu: 0.2 to 1. 〇% by mass, Mg: 0.2 to 1_〇% by mass, Ti: 〇'〇02~〇·20 mass 0/〇, and Zr: 0.05 to 0.20% by mass, and Mn/Fe The mass ratio of 201242141 is 0.2 to 1.0, and the remainder is composed of gossip and unavoidable impurities', and the Si system which is an unavoidable impurity is less than 〇3〇 mass%. In the case of cold-rolled unannealed material, it is a tensile strength of 2% or more and a tensile strength of 160 MPa or more. Further, in the case of a cold-rolled annealed material, it is a tensile strength of 20% or more and a tensile strength of 丨3〇Mpa or more. Since the alloy sheet of the present invention has high strength and good moldability, and has excellent laser welding properties, it is possible to manufacture a container for a secondary battery which has excellent sealing performance and can suppress expansion at a low cost. In particular, in the case of cold-rolled unannealed material, it has an elongation value of 2% or more and a tensile strength of 16 GMPa or more, and in the case of a cold-rolled annealed material, not only has a tensile strength of 13 GMPa or more and an elongation value. Above 2 ()%, good formability is exhibited. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a conceptual diagram showing the number of abnormal beads/evaluation method, () is a plan view of the welded bead, and (8) is a graph showing the variation of the bead width along the length of the bead. Fig. 2 is a conceptual diagram illustrating a method of measuring/evaluating the depth of penetration, (a) is a plan view of the molten solder bead, and (B) is a cross-sectional view. ^ Form for carrying out the invention. The human power A is placed in a container after the electrode body is placed in a container, and is then fabricated by welding or the like. If such a secondary battery is used in action, the internal temperature of the barn rises when charging, and the pressure inside the container is lowered. Therefore, when the material strength of the molded container is too low, there is a problem that the container produced in the 201242141 has a large problem. Therefore, the material must have high strength. Further, since the pressing method is generally used as a method of molding a container, the material used itself must have good press formability. Further, since the method of sealing by covering the upper cover is a damascene method, it is also required to have excellent weldability. Further, as the welding method in the case of manufacturing two: under-electricity + container, etc., a laser welding method is often used. Further, regarding the problem of laser fusion, there are, for example, (1) stability of the width of the soldered bead, stability of the weld depth, and (7) obtaining a deeper penetration depth with respect to the width of the molten bead. As usual, the width of the welded bead is widened, and the depth of the refining has a tendency to increase. Therefore, the width of the welded bead may be locally generated in the abnormal bead portion, and the m depth may be increased. When it is severe, the penetration of the molten portion may occur, which may cause a decrease in battery performance or availability. On the other hand, in order to investigate the depth of the sneak, it is necessary to observe the addition of multiple places, which is quite labor intensive. However, as mentioned above, in the same-alloy, the weld bead width is related to the depth of the ship. From this point of view, the problem can be easily touched by measuring the welded bead wide wire_abnormal (coarse) bead. The ratio of the beads to the abnormal depth of penetration. In order to obtain a high-strength and excellent press-formability, the present-mentioned person and the like, and through the generation of the number of abnormal weld beads in the joint portion, the depth of penetration in the joint portion is found to be arbitrarily Repeat the fine review to achieve the present invention. The contents are explained below. 201242141 First, the action, the appropriate content, and the like of each element contained in the aluminum alloy plate for a secondary battery container of the present invention will be described.

Fe : 0.3 to 1.5% by mass F e is an essential element for increasing the strength of the aluminum alloy sheet and ensuring the penetration depth of the laser welding. If the Fe content is less than 〇3 mass%, the strength of the aluminum alloy sheet is lowered and the penetration depth at the time of laser welding is reduced, which is not preferable. When the Fe content is more than 1.5% by mass, a coarse intermetallic compound such as Ai_(Fe · Mn)-Si-based or Al0Fe is crystallized during casting, and the formability of the final sheet is lowered, and the fusion is performed at the time of laser fusion. The metal compound is more likely to evaporate than the A ruthenium matrix, and the number of abnormal beads is increased and the weldability is lowered, which is not preferable. Therefore, the Fe content is set in the range of 5% by mass. The desirable Fe content is 0.5 to 1.5 mass. / Range of ◦. More desirably, the content is in the range of 〇ί 5 % by mass. Μη : 0.3~1.0 mass % Μη is an essential element for increasing the strength of the aluminum alloy sheet and ensuring the penetration depth of the laser welding. If the content of Μη is less than 〇3% by mass, the strength of the aluminum alloy sheet is lowered and the penetration depth at the time of laser welding is reduced, so that the non-ideal Μη contains s if it exceeds 〇% by mass, and is cast in the ingot. When the coarse intermetallic compound such as Al-(Fe.Mn)-Si and AUMn is crystallized, the formability of the final sheet is lowered, and the metal compound is easier to compare with the A1 matrix during laser welding. Evaporation increases the number of abnormal beads and reduces the weldability, which is not desirable. Therefore, the Μη content is set in the range of 0.34 〇 mass%. A more desirable Μη content is in the range of 0.3 to 0.8% by mass. More ideal ^^^ content in 〇 4~〇 7 8 201242141 quality. /. The scope.

Ti : 0.002~0.20 mass 0

Ti acts as a grain refiner to prevent pray cracking when the ingot is cast. Of course, Ti can be added alone, but by coexistence with B, a sharpening effect of strong crystal grains can be expected. Therefore, Al-5% Ti-l% B or the like can be added by a rod type hardening machine.

If the Ti content is less than 0.002% by mass, the effect of miniaturization at the time of casting the ingot is insufficient, so that it is not preferable because of the occurrence of casting cracks. In addition, when the Ti content is more than 0.20% by mass, a coarse intermetallic compound such as ruthenium 3 crystallizes during casting of the ingot, and the formability of the final sheet is lowered, which is not preferable. Therefore, the Ti content is set in the range of 0.002 to 0.20% by mass. A desirable Ti content is in the range of 0.002 to 0.15 mass%. More preferably, the content of butyl ruthenium is in the range of 0.005 to 0.10% by mass.

Zr : 0·05~0.20% by mass

Like Ti, Zr acts as a grain refiner to prevent casting cracks when the ingot is cast. Further, by coexisting the butadiene and the heart, it is possible to prevent the occurrence of cracks in the welded bead portion which is rapidly solidified and solidified, and to increase the speed of the pulsed laser welding. When Ti, Zr, and B are coexisted, the effect of preventing cracking of the welded bead portion accompanying rapid solidification during solidification can be made more remarkable.

When the Zr content exceeds 〇2% by mass, a coarse intermetallic compound such as ZrAb is crystallized during casting of the ingot, and the formability of the final sheet is lowered. If the Zr content is less than 〇05.5% by mass, a sufficient effect cannot be obtained. Therefore, the ideal Zr content is 〇.〇5 to 0_20% by mass. The desirable Zr content is in the range of 〜·〇7 to 0.20% by mass. A more desirable Zr content is in the range of 〇.〇7~〇. 18% by mass 201242141. B: 0·〇〇〇5 to o.io% by mass Β Similarly, Ti and Zr can be used as a grain refining agent to prevent casting cracks during casting of the ingot. Therefore, it can be included as needed. When B contains more than 〇1% by mass, TiB2 becomes a stabilized metalloid compound, and the grain refining effect is attenuated, and it is not desirable because the skin is roughened after the formation of DI. If the B content is less than 0.0005 mass ❶ / 〇, sufficient grain miniaturization effect cannot be obtained. Therefore, the ideal B content is 〇·〇〇〇5~〇_1〇% by mass. The ideal β content is in the range of 质量.〇〇卜〇 〇5 mass%. A more desirable strontium content is in the range of 0.001 to 〇.〇1% by mass.

Cu content: 〇·2~1.〇Quality 〇/〇

Cu is precipitated into the ruthenium matrix by precipitation with Mg as a CuMgAl2 phase to increase the strength of the aluminum alloy sheet. If the Cu content is less than 0.2% by mass, the increase in strength may be insufficient, which is not preferable. On the other hand, if the CU content is more than 1.0 mass, the formability of the final sheet is lowered, which is not preferable. Therefore, the 'Cu content is set in the range of 0.2 to 1.0% by mass. The desirable Cu content is in the range of 〇·2 to 0.9% by mass. A more desirable Cu content is in the range of 〇2 to 〇8 mass ° / 〇.

Mg content: 〇.2~1.0% by mass

The Mg system is precipitated into the A1 matrix by Cu as a CuMgAh phase, and the strength of the aluminum alloy sheet is increased. If the Mg content is less than 0.2% by mass, the increase in strength may be insufficient, which is not preferable. On the other hand, when the content of Mg is more than 1.0% by mass, the oxide film is generated during laser welding, and the weldability is lowered, which is not preferable. 201242141 Therefore, the Mg content is set in the range of 0.2 to 1% by mass. A desirable Mg content is in the range of 0.2 to 0.9% by mass. More preferably, the Mg content is in the range of 〇.2 to 〇.8 mass%. Si content as an unavoidable impurity: less than 〇.3 〇 mass% The Si content as an unavoidable impurity is preferably limited to less than 〇 3 〇 mass %. If the Si content is more than 〇.30 stalks or more, when the ingot is cast, a coarse intermetallic compound such as Al-(Fe·Mn)-Si is crystallized to lower the formability. A desirable Si content is less than 0.25 mass%. A more desirable Si content is less than 0.20% by mass. In the present invention, as long as the Si content is less than 0.20 mass. /. There is no deterioration in properties such as formability and weldability. Other unavoidable impurities Unavoidable impurities are inevitably mixed from bare metal or recycled waste materials. For example, the allowable content of Zn is less than 〇.25 mass. /〇; Ni is less than 0.20% by mass; G^v is less than 〇.〇5 mass%; Pb, Bi, Sn, Na, Ca 'Sr are respectively less than 0.02% by mass; and others are less than 〇〇5 mass% As long as the elements other than the management are contained within the range, the effects of the present invention are not hindered.

Mass ratio of Mn/Fe: on 〇 In the range of Fe and Μη contents within the range of the present invention, if the Mn/Fe ratio is less than 0.2, the penetration depth at the time of laser welding is reduced, which is not preferable. In the range of Fe and Μη contents within the scope of the present invention, if the Mn/Fe ratio exceeds L〇, the number of abnormal beads increases, which is not preferable. In addition, the mass ratio of Mn/Fe affects the type and amount of the intermetallic metal 201242141 compound crystallized during ingot casting. For example, it is known that as the mass ratio of Mn/Fe increases, the amount of 介^Μη intermetallic compound also increases. On the other hand, when the laser is welded, the metal compound such as Α丨όΜη is more likely to evaporate and be unstable than the metallocene compound such as A1 Fe-Si, Alje or AbFe. Therefore, if the Mn/Fe ratio exceeds ?!, 可能, the number of abnormal beads may be increased when the laser is welded, and the weldability may be lowered. Further, Μη is added to the A1 matrix to increase the thermal resistance of the material, and therefore is an element more important than Fe in terms of ensuring the penetration depth at the time of laser welding. Therefore, if the Mn/Fe ratio is lower than 〇.2, the penetration depth at the time of laser welding may be insufficient. Tensile strength and elongation value Cold-rolled unannealed material: elongation value of 2% or more and tensile strength of 160 MPa or more, cold-rolled annealed material: elongation value of 2% or more and tensile strength of 130 MPa or more, and Al-Fe-based aluminum alloy When the board is suitable for large lithium-ion battery containers, etc., it must not only have high strength and good laser fusion, but also good formability. The strength of the material can be known as the tensile strength at the time of the tensile test. Further, the formability can be known from the elongation value at the time of the tensile test. As will be described in detail in the examples to be described later, the Al-Fe-based alloy sheet of the present invention which is suitable for use in large chain ion battery theft, etc., is an extension value of 2% or more when it is cold-rolled unannealed material. It is preferable to have a tensile strength of 16 MPa or more; and a cold rolled annealed material is preferably one having an elongation value of 20% or more and a tensile strength of 130 MPa or more. The number of the second phase particles having a circle equivalent diameter of 5 μm or more in the metal structure is less than 5 〇〇/mm 2 12 201242141 The above characteristics can be erroneously adjusted by carefully adjusting the Al-Fe-based aluminum alloy plate having the specific chemical composition described above. The metal structure appears. Specifically, the number of second phase particles having a circle equivalent diameter of 5 μm or more in the metal structure may be less than 500/mm2. There is no difference in the metal structure whether it is cold rolled unannealed material or cold rolled annealed material. As long as it has the metal structure as described above, the cold-rolled unannealed material exhibits an elongation value of 2% or more and a tensile strength of i60 MPa or more, and the cold-rolled annealed material exhibits an elongation value of 20% or more and a tensile strength of 130 MPa or more. . Next, a method of manufacturing a gold plate for a secondary battery container as described above will be briefly described. Melting and melting ^ Put the raw materials into the melting furnace, and appropriately inject the miscellaneous (four) rows (4) when the predetermined melting temperature is reached, and then wait for the demand to be tempered, then degas after the furnace, and then calmly maintain, and then from the surface of the material. Separate and smash. People recognize that Qiao α takes the topping of the alloy composition, although the mother: from Shaohe 2 raw materials investment is also # important 'But until the above-mentioned agent and refining is extremely: important juice noodles, fully calm when calming time It is advisable to take more than 30 minutes. In order to let the furnace of the furnace, the furnace is moved to the heart of the town (four) for 45 minutes or more. Heart (4) Depending on the demand, it can also be degassed and smashed through the line. Among them, the type in which the inert gas or the like is sprayed into the bubble of the inert gas from the rotary rotor to remove the type is 13 201242141. When nitrogen is used as the inert gas, it is important to manage the dew point to, for example, -60 ° C or less. The amount of hydrogen in the ingot should be reduced to less than 0.20 cc / 100 g. When the amount of hydrogen in the ingot is too large, voids are generated in the final solidified portion of the ingot, and therefore it is necessary to limit the rolling reduction per pass in the hot rolling step to, for example, 7% or more to eliminate voids. Moreover, although it may be different due to the homogenization treatment conditions before the hot rolling step, the hydrogen which is excessively saturated and solid-dissolved in the ingot may be precipitated during the laser welding after the formation of the final sheet, and Most of the pores are produced in the bead. Therefore, the preferred amount of hydrogen in the ingot is 0.15 cc/100 g or less. Cast ingots are manufactured by semi-continuous casting (DC casting). In the usual semi-continuous casting, since the thickness of the ingot is generally about 400 to 600 mm, the solidification cooling rate at the central portion of the ingot is about 1 ° C / sec. Therefore, especially when the high-Fe and Μη content aluminum alloy melt is semi-continuously cast, a coarse intermetallic compound such as Al-(Fe_Mn)-Si is crystallized from the aluminum alloy melt in the center of the ingot. tendency. Although the casting speed in semi-continuous casting varies depending on the width and thickness of the ingot, it is usually considered to be 50 to 70 mm/min in consideration of productivity. However, in the case of in-line degassing, considering the substantial residence time of the melt in the degassing tank, the flow rate of the chain solution (dissolution per unit time) varies depending on the degassing conditions such as the flow rate of the inert gas. The smaller the juice supply amount, the more the degassing efficiency in the tank can be increased and the possibility of reducing the amount of argon gas in the ingot can be achieved. Further, although the number of castings to be cast varies, etc., in order to reduce the amount of hydrogen in the ingot, the casting speed is preferably limited to 30 to 50 mm/min. A more ideal casting speed is 14 201242141 3〇~4〇mm/min. Of course, once the casting speed is lower than 3 〇mm/min, the productivity is lowered, which is not desirable. And, not to mention, the slower the casting speed, the more the slope of the sump (the interface of the solid phase/liquid phase) in the ingot can be relaxed, thereby preventing the casting crack. Homogenization treatment: 42 〇 to 600 ° C x 1 hour or more The ingot obtained by the semi-continuous casting method was subjected to homogenization treatment. The homogenization treatment is a process of holding the ingot at a height of /m to carry out casting segregation or releasing the residual stress inside the prayer piece in order to facilitate the rolling. In the present invention, it is necessary to maintain the temperature at 420 to 60 (TC is maintained for 1 hour or more. At this time, the homogenization treatment is also to dissolve the transitional tl which constitutes the intermetallic compound during casting, to some extent. When the holding temperature is too low or the temperature is kept too short, the solid solution of the above transition element or the like may not proceed, and the recrystallized grain may become coarse, and the DI forming may not be performed beautifully. Further, once the temperature is kept too high, a eutectic portion such as CuMgAl2 which causes a fine final solidification portion in the block is melted, that is, a so-called cast sinter is sintered. The ideal homogenization temperature is 42. 〇~59〇.〇. The hot rolling step is carried out after homogenization treatment of the ingot which has been kept at a high temperature for a predetermined period of time, and is directly lifted by the movable spreader and transferred to the hot rolling mill, and, although, due to the hot emulsion extension machine However, the hot-rolled sheet is rolled up to the pro-thickness by a number of times of aging, and the hot-rolled sheet is rolled to the pro-cold-rolling step. The light of the extension plate passes through the cold rolling mill and usually The number of rows - the cold rolling of a person will be 1 due to the plastic strain induced by cold rolling, and the work hardening will be carried out from 201242141. Therefore, it can be visually kept warm (4) is also soft -===", The furnace is inserted into a cold roll and is maintained at a temperature of 3G (M5()t). The temperature is maintained below -3GGt, which will not promote softening. If the temperature exceeds 4 years, the processing cost will increase. If it is cooled rapidly by a continuous annealing furnace for a temperature of, for example, 45 passages to 55 generations (four times) for 15 seconds, it may also serve as a solution treatment. The temperature is maintained. If it is less than 45 〇c, it will not promote softening. More than 5 qing has the defects that cause the casting sand to be sintered. Final annealing In the present invention, the final annealing after the final cold rolling may also be batch processing, for example, by annealing the furnace to the temperature side ~ 5GGt: for 1 hour. However, if it is kept in a continuous annealing furnace for a period of 15 seconds, for example, the temperature of the thief is kept for 15 seconds, and then rapidly cooled, it may also serve as a coloring treatment. In any case, in the present invention, final annealing is not essential, but If considering the formability in the general DI forming, then In order to soften the final sheet as much as possible, it is preferable to consider the formability of the mold forming (four) towel as the annealed material or the solution treatment material. The mechanical strength is not the formability. In the case of cold rolled unannealed material, the final cold rolling rate at the final cold rolling rate is preferably in the range of 50 to 90%, as long as the final cold rolling rate is within the range, The average recrystallized grain of the final plate is 20~1〇〇μηι and the extension value is set to 20% or more, and then 16 201242141 can be beautifully finished after forming the skin. The ideal final cold rolling rate is 60~90%. On the other hand, the final cold rolling ratio when cold annealing unannealed material is not applied is preferably in the range of 5 to 40%. In the case of DI forming, if the sizing process is increased, it is necessary to provide a final plate which is slightly harder than the annealed material. If the final cold rolling rate is less than 5%, the composition may vary depending on the composition, but it may be difficult to set the tensile strength of the final sheet to 160 MPa or more, and if the final cold rolling ratio exceeds 4%, it may be difficult to The final plate extension is set at 2% or more. As long as the final cold rolling ratio is within this range, the elongation value of the cold rolled unannealed final sheet can be set to 2% or more and the tensile strength can be set to 16 MPa or more. More preferably, the final cold rolling rate is in the range of 1 〇 to 3 〇%. By the above-described general procedure, an aluminum alloy plate for a secondary battery container can be obtained. EXAMPLES Preparation of final sheet After pre-mixing various ingots, various ingots were metered and blended, and each of the ingots (total of 8 test materials) was inserted and filled into a fine load of the coated release material. Will be in violation of (four) into the electric furnace and to. c. Turning the removal of the smelt will keep the scent of the scent of the juice at 76 ° C. Next, remove the smudges and use 6 g of each of the auxiliaries to be placed in the aluminum drop and press in with a stopper. $Next' was inserted into the scented juice and sprayed into the N2 emulsion for 1 minute at a flow rate of l.OL/min for degassing. Then, for 30 minutes. The sedation of the clock, and then the slag of the float on the surface of the melt was removed, and the disc sample was taken into the mold for component analysis. 17 201242141 Come back again, use the jig to remove the crucible from the electric furnace in sequence, and tie the infusion to the preheated mold (250mmx200mmx30mm). The opening of each test material was analyzed by composition analysis by luminescence spectrometry. The results are shown in Table 1. Table 1: Component composition of the test material. Test material No. Component composition (% by mass) Mn/Fe Si Fe Μη Cu Mg Ti Zr B Example 1 0.08 1.28 0.50 0.51 0.51 0.08 0.10 0.005 0.39 Example 2 0.07 1.30 0.31 0.76 0.84 0.08 0.10 0.004 0.24 Example 3 0.07 1.27 0.50 0.51 0.51 0.16 0.10 0.006 0.39 Example 4 0.08 1.26 0.52 0.51 0.51 0.08 0.17 0.002 0.41 Example 5 0.08 1.22 0.49 0.30 0.32 0.03 0.05 0.002 0.40 Comparative Example 1 0.24 0.49 1.27 0.26 0.53 0.02 0.003 0.001 2.59 Comparative Example 2 0.07 1.60 0.94 <0.01 <0.01 0.004 0.002 0.002 0.59 Comparative Example 3 0.01 0.011 <0.01 <0.01 <0.01 0.002 0.001 0.002 - Comparative Example 4 0.015 0.28 <0.01 <0.01 < 0.01 0.002 0.001 0.001 - Comparative Example 5 0.015 0.015 0.28 <0.01 <0.01 0.002 0.001 0.001 18.7 Comparative Example 6 0.5 1.24 0.49 0.52 0.53 0.08 0.10 - 0.40 The ingot was cut into 2 mrn after cutting the ingot head. Thickness 26mm ° The ingot is inserted into an electric heating furnace, heated to 430 C at a heating rate of 10 ° C / hr for homogenization at 430 ° C for 1 hour, and then hot rolling Extension for rolling up until a thickness of 6mm. A cold rolling was applied to the hot rolled sheet to obtain a cold rolled sheet having a thickness of 1.25111111. The cold rolled sheet was inserted into an annealing apparatus and subjected to an intermediate annealing treatment maintained for 39 hours. The annealed sheet was taken out from the annealing apparatus and air-cooled. Next, cold rolling was applied to the annealed sheet to obtain a cold rolled sheet having a thickness of 1 mm. 18 201242141 The final cold rolling rate at this time is 20%. The cold-rolled annealed sheet was subjected to an intermediate annealing without applying an intermediate annealing to the hot rolled sheet to obtain a cold rolled sheet of 1 mm. The final cold rolling ratio at this time was 83. The final annealing system was performed by inserting a cold-rolled sheet into an annealing apparatus for 39 Torr: after an annealing treatment for 1 hour, the cold-rolled sheet was taken out from the annealing apparatus and air-cooled. Next, the final sheet (each test piece) obtained by the above method was evaluated for formability and laser weldability. The evaluation of the formability of the final sheet obtained by the evaluation of the formability was carried out by extension (%) of the tensile test. Specifically, the JIS No. 5 test piece was taken in such a manner that the stretching direction was parallel to the rolling direction, and the tensile test was performed in accordance with JIS Z 2241, and tensile strength (UTS), 0.2% proof stress (YS), and elongation (fracture were calculated). extend). In the cold-rolled unannealed final sheet, the test material having a stretch value of 2% or more was excellent in formability (〇), and the test material having less than 2% was poor in formability (X). The evaluation results are shown in Table 2. In the final sheet to which annealing was applied after cold rolling, the test material having a stretching value of 20% or more was excellent in formability (〇), and the test material having less than 20% was poor in formability (X). The evaluation results are shown in Table 3. In addition, the test material No. in Table 3 is represented by the number of the number of digits of each of the test materials No. shown in Table 1. Laser welding conditions Pulsed laser irradiation was performed on the final plate obtained for laser fusion evaluation. Using the YAG laser welding machine JK701, 201242141 manufactured by LUMONICS, at the frequency of 37.5 Hz, the fusion speed of 450 mm/min, the energy per pulse of 6 〇j, and the shielding gas (nitrogen) flow rate l_5 (L/min), The two sheets of the test piece were joined in such a manner that the ends were free of each other, and a pulsed laser welding of a total length of 120 mm was performed along the portion. Evaluation of Laser Weldability Measurement/Evaluation of Abnormal Beads Next, the number of abnormal beads generated in the welded portion was measured in terms of laser weldability evaluation. First, among the above-mentioned 120 mm long weld lines, the weld line of the center portion 6 1111 is determined as the measurement area. Further, as shown in the figure, the width of the round-up welding bead formed by the pulse formed along the 6 mm long wire is continuously measured at intervals of 〇.〇5 mm in the welding direction, and each is calculated. After the "average weld bead width" of the long (1 section), the count shows the number of "average weld bead width" deviation ratios in each section at the bead width of 1 Ux. The total number of "Holidays is 60 mm (6 intervals) is taken as the number of abnormal beads of the test material. In this specification, the number of abnormal weld beads is less than 1〇, and the number of abnormal weld beads is a good (〇)', and the number of abnormal weld beads is 1 () or more. Review (10)). The evaluation results of the cold-dried untwisted materials are shown in Table 2, and the evaluation results of the cold-rolled annealed sheets are shown in Table 3. ^ Measurement/Evaluation of the Dying Intensity Next, the melting in the welded portion is determined by the laser fusion evaluation. Into the depth: As shown in Fig. 2, the plate in the direction perpendicular to the welding direction is cut and embedded in the thermoplastic resin to be mirror-polished to observe the metal structure of the vertical cross section. The mesometallic compound crystallized during casting is irradiated with ',' by pulsed laser, and is increased to m and melted in aluminum. Immediately afterwards, the molten bead is fused to 20 201242141 to be quenched to form the aforementioned intermetallic metal. Fe, Μη of the compound, a structure which is solid-solubilized in an AI matrix by supersaturation of an element. Therefore, by observing the metal structure of the vertical section of the splicing portion, only the region of the A1 matrix in which the intermetallic compound is not observed is a new portion in the cross section, and the maximum depth of the 疋 玄 区域 region from the final plate surface can be determined. Dissolution depth. The melting depth of the five sections was measured for the test piece, and the average value was taken as the penetration depth (μιη) in the test piece. In this case, the cross section in the abnormal bead is outside the measurement target. In this Soul book, the test material with a melt penetration depth of 22 〇μηη is well evaluated for the penetration depth (〇), and the test material with a melt penetration depth lower than 220 μη is the poor evaluation of the penetration depth (X). . The evaluation results of the cold-rolled unannealed materials are shown in Table 2' and the evaluation results of the cold-rolled annealed sheets are shown in Table 3. Table 2: Evaluation results of the test materials (cold rolled unannealed materials)

Test material No. Abnormal weld bead number Melting depth Tensile property Abnormal weld bead melt formability (3⁄4 extension) 4kW (μηι) UTS (MPa) YS (MPa) Extension (%) Example 1 6 249 214 213 3 〇〇〇Example 2 7 371 225 219 4 〇〇〇 Example 3 6 253 219 217 3 〇〇〇 Example 4 6 " —— 283 236 235 2 〇〇〇 Example 5 1 229 198 190 5 〇〇 〇Comparative Example 1 19 276 226 217 3 X 〇〇Comparative Example 2 13 355 140 136 <1 X 〇X Comparative Example 3 0 185 68 67 8 〇X 〇Comparative Example 4 0 199 91 89 16 〇X 〇Comparative Example 5 0 179 85 85 6 〇X 〇Comparative Example 6 2 251 224 222 <1 〇〇X Table 3: Evaluation results of the test materials (cold rolled annealed materials) 21 201242141

Test material No. Abnormal weld bead number Melting depth Tensile property Abnormal weld bead melt formability (extension) 4kW (μηι) UTS (MPa) YS (MPa) Extension (%) Example 11 1 228 165 90 28 〇 〇〇Example 12 8 352 185 123 1 21 〇〇〇Example 13 7 241 167 91 25 〇〇〇Example 14 5 234 166 89 26 〇〇〇Example 15 0 222 135 80 29 〇〇〇Comparative Example 11 20 261 160 100 25 X 〇〇Comparative Example 12 11 340 168 90 17 X 〇X Comparative Example 13 0 196 67 29 45 〇X 〇Comparative Example 14 0 205 70 30 43 〇X 〇Comparative Example 15 0 208 75 41 38 〇 X 〇 Comparative Example 16 1 238 170 92 19 〇〇X Evaluation of each test material shows that in Table 2 regarding the evaluation results of the cold-rolled unannealed material, Examples 1 to 5 are cold-rolled materials within the composition range of the present invention. 'The laser fusion properties (abnormal weld bead number evaluation, ~ depth evaluation), and formability are good (〇). The P 匕 flat 1 1J 1 dry Μ η content is 1.27% by mass and the Mn/Fe ratio is also 2.59 outside the scope of the present invention, although the depth is well evaluated (〇) and used well (〇) 'but the number of abnormal beads Poor assessment (X). In the case of the vehicle example 2, the Fe content is as high as 16% by mass in the range of the present invention (,), but the impurity is not (10)) and the different beads are compared with the examples 3 to 5, and the Ayf u is low in Fe and Mn. Outside the scope of the present invention, the evaluation of the number of abnormal beads is good (〇)' but dissolves, 22 201242141 In Comparative Example 6, the Si4 denier dadden into depth evaluation k W is G.5fM% in the present invention. Outside the range, although the shape is poor (I. Yi (0) and the number of abnormal weld beads is well evaluated (〇), but the ".· page shows the results of the evaluation of the results of the evaluation of the results of the cold rolling and annealing of 11~15ΑϋΒΒ, Example Weld Bead Yuan 1, the composition of the dry 15 _ readback, laser fusion (abnormal material, to depth evaluation), and forming (four) good (〇). In the car father example 11, the _ content is 127 quality % and the batch is also outside the scope of the present invention, although the evaluation of the penetration depth is good (〇) and the formability is good (〇), but the abnormal number of beads is poorly evaluated (x). In Comparative Example 12, although the penetration depth is The evaluation number is poorly evaluated (x).

The Fe content is still 丨6 mass 0/. In addition to the scope of the present invention, it is good (〇), but the moldability is poor (χ) and the abnormal ruthenium ruthenium is lower than Fe and Μη in Examples 13 to 15, and the formability is good (〇) and abnormal outside the scope of the present invention. The number of beads was well evaluated (Ο), but the depth of the smear was poorly evaluated (X). In Comparative Example 16, 'Si contains 1 direction as 〇_5 mass. /β is outside the scope of the present invention, although the evaluation of the depth of dissolution is good (the evaluation of the number of abnormal beads in the Minjiang River is good (〇), but the formability is poor (X). The number of particles in the second phase of the metal structure is determined and obtained. The longitudinal direction of the final sheet is parallel to the longitudinal section (a section perpendicular to the LT direction), which is cut into the thermoplastic resin of the New Zealand for mirror polishing, and then metal-aged. Photomicrographs are taken by optical photographic mirrors. 1 area of the field of view: 〇Q334mm2, 1 〇 field of view for each sample) and image analysis of the photo 'to determine the number of particles of the second phase equivalent to 23 201242141 diameter 5μηι or more per unit area. Table 4: 2 Phase/grain + sale (unit: one / _2) (cold rolled unannealed material) The measurement results of the image analysis of the cold unannealed material are shown in Table 4, and the image analysis of the cold rolled annealed sheet is determined. The results are shown in Table 5. Test material No. ---~~~-1 Circle equivalent diameter 5 μηι or more Example 1 201 Example 2 ---------J 173 Example 3 401 Example 4 259 Comparative Example 1 398 Comparative Example 2 1007 Comparative Example 3 0 Comparative Example 4 0 Comparative Example 5 0 Comparative Example 6-- ------- 614 Table 5. Number of second phase particles (unit: piece / mm2) (cold rolled annealed material) Test material No. Round equivalent diameter 5 μmη or more Example 11 152 Example 12 182 ~ ~ Example 13 380 Example 14 276 Comparative Example 11 413 Comparative Example 12 965 Comparative Example 13 ------- 1 Comparative Example 14 0 Comparative Example 15 - A 0 Comparative Example 16 553 From showing related cold-rolled unannealed materials Table 4 of the evaluation results shows that in the case where the number of the second phase particles having a circle equivalent diameter of 5 μm or more in the genus of gold 24 201242141 is 5 〇〇/mm 2 or more (Comparative Examples 2 and 6), In the tensile test, peeling is likely to occur at the interface between the coarser second phase particles and the substrate, so that the elongation value is lowered to less than 2%. Therefore, it is understood that in order to make the elongation value 2°/. or more, it is necessary to make The number of second phase particles having a circle equivalent diameter of 5 μm or more in the metal structure is less than 5 〇〇/mm 2 ° From the table 5 showing the evaluation results of the cold rolled annealed material, the circular equivalent diameter in the metal structure is known. When the number of second phase particles having a length of 5 μm or more is 5 〇〇/m cation 2 or more (Comparative Examples 12 and 16), in the tensile test, The interface between the coarse second phase particles and the matrix produces _, and the value of the extension will become lower than 20%. Therefore, 'it is known that in order to make the extension value above 2%, the circle in the metal structure must be equivalent. The number of second phase particles having a diameter of 5 μm or more is less than 5 Å/mm 2 . INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a high strength which is applicable to a large-sized ion battery container, and is excellent in impurities. _ 接接纽赖如如铭合金板. [Simple diagram of the drawing, Fig. 1 is a conceptual diagram showing the number of abnormally welded beads, and the evaluation of the width of the bead in the longitudinal direction of the welding bead. Fig. 2 is a conceptual diagram illustrating the measurement/evaluation method of the glazing depth, (8) 25 201242141 is a plan view of the welded bead, and (B) is a sectional view. [Main component symbol description] (none) 26

Claims (1)

201242141 VII. Patent application scope: 1. An aluminum alloy plate for a battery case which is excellent in formability and weldability, characterized in that it is a cold-rolled unannealed material and has the following chemical composition and a circular equivalent diameter of 5 μηι or more. The second phase particle number is less than 5 〇 (H@/mm2 metal structure 'and exhibits an elongation value of 2% or more and a tensile strength of 16 〇Mpa or more; the chemical composition is: contains Fe: 〇·3~1.5 Mass. /, Μη: 0.3 to 1.0% by mass, Cu: 0.2 to 1.0 mass, Mg: 0.2 to 1.0 mass. /〇, Ti: 0.002 to 0.20% by mass, and & : 〇〇5 to 〇2〇0 /〇% by mass, and the mass ratio of Mn/Fe is 0.2 to 1.0, and the remainder is composed of gossip and unavoidable impurities' and the Si system as the unavoidable impurity is less than 〇3 〇 mass%. 2. An aluminum alloy sheet for a battery case which is excellent in moldability and weldability, and which is characterized in that it is a cold-rolled annealed material and has a chemical composition and a circular phase equivalent diameter of 5 μm or more and a low number of second phase particles On a metal structure of 5〇〇/mm2, and exhibiting a tensile strength of more than 20% of the elongation value Degree; the chemical composition is: containing Fe: 0.3 to 1.5% by mass, Μη: 0.3 to 1.0% by mass, Cu: 0.2 to 1.0 mass, /, Mg: 0.2 to 1.0 mass. / 〇, Ti: 0.002-0.20 mass %, and Zr: 〇.〇5~0.20% by mass, and the mass ratio of Mn/Fe is 0.2~1_0' and the remaining part is composed of a丨 and unavoidable impurities, and the Si system is an unavoidable impurity. Less than 0.30% by mass.