TWI464276B - Aluminum-magnesium alloy sheet for anode and method of making the same - Google Patents

Description

Aluminum-magnesium alloy sheet for anode and manufacturing method thereof

The present invention relates to an aluminum-magnesium alloy sheet and a method for producing the same, and in particular to an aluminum-magnesium alloy sheet for an anode having excellent color uniformity and a method for producing the same.

After the anode treatment, the aluminum-magnesium alloy sheet has many excellent characteristics, so it can be applied to many different fields. For example, the anodized aluminum-magnesium alloy sheet can be light in texture, good in corrosion resistance and good in formability. It is widely used in mobile phones, desk machines, notebooks, tablet computers and other electronic products or other livelihood products.

However, the anodized aluminum-magnesium alloy sheet often suffers from yellowish yellow color, and the yellowish color of the aluminum-magnesium alloy sheet tends to cause the consumer to have an old and cheap feeling, thereby affecting the consumer's willingness to purchase.

In addition, nowadays, it is usually necessary to manufacture all the parts separately and finally assemble them. Anodizing is also performed when each part is manufactured. However, when the above parts are respectively subjected to anodizing, the mechanical properties of the different parts are often different, so that the parts are not subjected to the anodizing treatment under the same process conditions, and the color of each part is not First, the problem of poor uniformity of the overall color of the product occurs.

In order to solve the problem of yellowish color of the above-mentioned aluminum-magnesium alloy sheet, the industry is currently trying to control the content of impurities iron (Fe) and bismuth (Si) in the aluminum-magnesium alloy, and to add a trace amount of alloying elements [such as chromium (Cr) and manganese (for example). Mn)] to assist in changing or stabilizing the precipitated phase to obtain the desired surface color. However, the above-mentioned trace amounts of alloying elements are relatively high, which increases the cost of the process. Moreover, the conventional method still cannot solve the problem of poor uniformity of color of each part.

In view of this, it is urgent to propose an aluminum-magnesium alloy sheet for an anode and a method for producing the same, thereby improving various problems in the process of the conventional aluminum-magnesium alloy sheet for anode.

Therefore, an aspect of the present invention provides a method for producing an aluminum-magnesium alloy sheet for an anode, which is a method for controlling a thickness reduction ratio of an aluminum-magnesium alloy casting blank in a cold rolling step and a relative difference density of an annealing heat treatment step, thereby An aluminum-magnesium alloy sheet for an anode having excellent color uniformity is formed.

Next, another aspect of the present invention provides an aluminum-magnesium alloy sheet for an anode, wherein the aforementioned aluminum-magnesium alloy sheet for anode has a relative difference in density (%) of from 0% to 90%, and a relative value of Δb It is no more than 0.3.

According to the above aspect of the invention, a method of producing an aluminum-magnesium alloy sheet for an anode is proposed. In an embodiment, first, an aluminum-magnesium alloy casting is provided, wherein the aluminum-magnesium alloy may include, but is not limited to, 0 to 0.25 weight percent bismuth, 0 weight percent to 0.7 weight percent iron, and 0 weight percent to 0.1 weight. Percentage of copper, 0% by weight to 0.1% by weight of manganese, 0% by weight to 0.1% by weight of zinc, 2.2% by weight to 2.8% by weight of magnesium, 0.15% by weight to 0.35% by weight The percentage of chromium, and the rest is aluminum and other inevitable impurities.

Next, the aluminum-magnesium alloy slab is subjected to a homogenization heat treatment step, wherein the heating temperature of the homogenization heat treatment step may be, for example, 500 ° C to 530 ° C.

Then, the aluminum-magnesium alloy slab subjected to the homogenization heat treatment step is subjected to a hot rolling step to form a first aluminum-magnesium alloy sheet, wherein the first aluminum-magnesium alloy sheet has a hot-rolled thickness, and the hot-rolling temperature of the hot-rolling step is Not less than 300 °C.

Subsequently, the first aluminum-magnesium alloy sheet is subjected to a cold rolling step to form a second aluminum-magnesium alloy sheet, wherein the second aluminum-magnesium alloy sheet has a cold rolling thickness and a reference hardness upper limit, the hot rolling thickness and the cold rolling thickness There is a difference, and the ratio of the difference to the thickness of the hot rolling described above is not less than 60%.

Thereafter, the second aluminum-magnesium alloy sheet is subjected to an annealing heat treatment step at 150 ° C to 320 ° C for 1 hour to 10 hours to obtain a third aluminum-magnesium alloy sheet, wherein after the annealing heat treatment step of 150 ° C to less than 320 ° C The aluminum-magnesium alloy sheet has an annealing hardness. After the annealing heat treatment step at 320 ° C, the third aluminum-magnesium alloy sheet has a lower reference hardness limit, and the third aluminum-magnesium alloy sheet has a relative difference from the following formula (I). Density (%) is 0% to 90%: relative poor discharge density (%) = (annealing hardness - reference hardness lower limit) / (hardness upper limit reference value - reference hardness lower limit) × 100% (I).

Subsequently, the third aluminum-magnesium alloy sheet is subjected to an anodizing step, which is carried out at an operating voltage of 20 ° C, 12.5 to 13.0 volts, an operating current of 3 amps, and an electrolyte containing a sulfuric acid concentration of 180 g/liter. An annealing heat treatment step of 150 ° C to less than 320 ° C and passing through the anode The third aluminum-magnesium alloy sheet after the processing step has a color difference measurement value, the third aluminum-magnesium alloy sheet after the annealing treatment step of 320 ° C and the anode treatment step has a color difference reference value, and the third aluminum-magnesium alloy sheet is composed of the following formula (II) One color difference relative value (Δb) is obtained and the color difference relative value (Δb) is not more than 0.3: color difference relative value=color difference measurement value-color difference reference value (II).

According to an embodiment of the invention, the ratio of the difference to the thickness of the hot rolling may be, for example, 60% to 90%.

According to the above aspect of the invention, there is proposed an aluminum-magnesium alloy sheet for an anode which is obtained by the above method.

The aluminum-magnesium alloy sheet for anode according to the present invention and a manufacturing method thereof are used for controlling the thickness reduction ratio of the aluminum-magnesium alloy casting blank in the cold rolling step and the relative difference density of the annealing heat treatment step, thereby forming the appearance uniformity of color uniformity. The anode is made of an aluminum-magnesium alloy sheet, and overcomes the disadvantages of the yellow-yellow or uneven color of the aluminum-magnesium alloy sheet for the anode.

100‧‧‧ method

110‧‧‧Provide the steps of casting aluminum-magnesium alloy

120‧‧‧Aluminum-magnesium alloy casting embryos are subjected to homogenization heat treatment steps

130‧‧‧Aluminum-magnesium alloy castings are subjected to a hot rolling step to form a first aluminum-magnesium alloy sheet

140‧‧‧The first aluminum-magnesium alloy sheet is subjected to a cold rolling step to form a second aluminum-magnesium alloy sheet

150‧‧‧A second aluminum-magnesium alloy sheet is subjected to an annealing heat treatment step to form a third aluminum-magnesium alloy sheet

160‧‧‧A third aluminum-magnesium alloy sheet is subjected to an anodizing step to form an aluminum-magnesium alloy sheet for the anode

The above and other objects, features, advantages and embodiments of the present invention will become more <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; A flow chart of a method of manufacturing a sheet.

As described above, the present invention provides an aluminum-magnesium alloy sheet for an anode and a method for producing the same, which is for controlling thickness reduction of an aluminum-magnesium alloy casting blank in a cold rolling step. The ratio and the relative poor discharge density of the annealing heat treatment step, thereby forming an aluminum-magnesium alloy sheet for an anode having good color uniformity. The aluminum-magnesium alloy sheet for anodes of the present invention and a method for producing the same will be described below.

Method for manufacturing aluminum-magnesium alloy sheet for anode

Referring to FIG. 1, a schematic flow chart of a method for manufacturing an aluminum-magnesium alloy sheet for an anode according to an embodiment of the present invention is shown.

1. Provide aluminum-magnesium alloy casting embryo

In Fig. 1, first, a method for manufacturing an aluminum-magnesium alloy sheet for an anode is provided as shown in step 110, and an aluminum-magnesium alloy casting embryo is provided, wherein the aluminum-magnesium alloy casting embryo contains at least 0 to 0.25 weight percent of ruthenium, 0 Weight percent to 0.7 weight percent iron, 0 weight percent to 0.1 weight percent copper, 0 weight percent to 0.1 weight percent manganese, 0 weight percent to 0.1 weight percent zinc, 2.2 weight percent to 2.8 weight percent magnesium, 0.15 The weight percentage is 0.35 weight percent chromium and the remainder is aluminum and other unavoidable impurities. In an embodiment, the aluminum-magnesium alloy slab may be formed, for example, by a casting molding step.

In one embodiment, the aluminum-magnesium-based alloy described above may be of any origin, and may include, but is not limited to, aluminum-magnesium-based alloy raw materials, waste materials produced in an industrial process, recycled materials, or any combination thereof. In an example, the aluminum-magnesium alloy described above may be, for example, a 5052-series aluminum alloy.

2. Perform a homogenization heat treatment step

Next, as shown in step 120, at a heating temperature of 500 ° C to 530 The above-mentioned aluminum-magnesium alloy casting embryo is subjected to a homogenization heat treatment step at °C to homogenize the alloy composition in the aluminum-magnesium alloy casting embryo. In one embodiment, the homogenization heat treatment step has a duration of from 3 hours to 30 hours.

3. Perform the hot rolling step

Next, as shown in step 130, the aluminum-magnesium alloy casting body of the homogenization heat treatment step is subjected to a hot rolling step at a hot rolling temperature of not less than 300 ° C to form a first aluminum-magnesium alloy sheet, wherein the first aluminum magnesium The alloy flakes have a hot rolled thickness. In an embodiment, the hot rolling step may be performed by performing hot rolling preheating at 500 ° C to 530 ° C after the step 120 is performed, and the preheating duration is 1 hour to 2 hours, and the heat of the hot rolling step is hot. The finishing temperature is not less than 300 ° C, or the homogenization heat treatment step is not carried out, and the preheating step (ie, the preheating and homogenization heat treatment effect) is directly performed, and the aluminum magnesium alloy casting embryo is heated in the preheating furnace at a temperature of 500 ° C to 530 ° C. Preheating is carried out for 3 to 10 hours, and the hot rolling temperature of the hot rolling step is not less than 300 °C. In one example, the hot rolling temperature of the hot rolling step can be, for example, about 330 °C. In another illustration, the hot rolled thickness may be, for example, 5 to 7 mm.

4. Perform the cold rolling step

Next, as shown in step 140, the first aluminum-magnesium alloy sheet is subjected to a cold rolling step to form a second aluminum-magnesium alloy sheet, wherein the second aluminum-magnesium alloy sheet has a cold rolled thickness and a reference hardness upper limit. In one embodiment, the aforementioned cold rolled thickness may be, for example, 0.6 to 1 mm.

Secondly, one of the features of the method of the invention is to control the cold rolling step The thickness reduction ratio is to improve the color uniformity of the subsequently obtained aluminum-magnesium alloy sheet for the anode. The thickness reduction ratio (%) referred to herein means the hot-rolled thickness of the first aluminum-magnesium alloy sheet and the second aluminum-magnesium alloy sheet after the first aluminum-magnesium alloy sheet is formed into the second aluminum-magnesium alloy sheet by the cold rolling step. The ratio of the difference between the cold rolled thickness and the hot rolled thickness. In one embodiment, the ratio of the difference to the thickness of the hot rolled (i.e., the thickness reduction ratio %) is not less than 60%, and preferably 60% to 90%.

5. Perform annealing heat treatment steps

Then, as shown in step 150, the second aluminum-magnesium alloy sheet is subjected to an annealing heat treatment step at 150 ° C to 320 ° C for 1 hour to 10 hours to obtain a third aluminum-magnesium alloy sheet, wherein 150 ° C to less than 320 ° C is obtained. The third aluminum-magnesium alloy sheet after the annealing heat treatment step has an annealing hardness, the third aluminum-magnesium alloy sheet after the annealing heat treatment step at 320 ° C has a lower reference hardness limit, and the third aluminum-magnesium alloy sheet can be obtained from the following formula (I) Relative difference density (%): relative difference density (%) = (annealing hardness - reference hardness lower limit) / (hardness upper limit reference - reference hardness lower limit) × 100% (I).

Another feature of the method of the present invention is to control the relative poor packing density of the annealing heat treatment step, thereby improving the color uniformity of the subsequently obtained aluminum-magnesium alloy sheet for the anode. In one embodiment, the relative difference in density (%) is determined based on the relative relationship of hardness, and the relative difference in density (%) of the third aluminum-magnesium alloy sheet is from 0% to 90%. Although the actual difference density of the alloy grain structure is not easy to calculate, the difference in density is positively correlated with the hardness of the alloy. The relative difference in the density of the alloys is determined by the relative relationship between the hardnesses. In addition, the second aluminum-magnesium alloy sheet is subjected to a cold rolling step, and thus has a higher differential discharge density with respect to the annealed heat-treated third aluminum-magnesium alloy sheet, so the hardness of the second aluminum-magnesium alloy sheet is defined as Refer to the upper limit of hardness. As for the lower limit of the reference hardness, the hardness value of the third aluminum-magnesium alloy sheet after the annealing heat treatment step of 320 ° C is defined, because in the annealing heat treatment step, although the higher the temperature, the annealing heat treatment can be lowered. The difference in the internal density of the aluminum-magnesium alloy sheet causes the hardness value of the third aluminum-magnesium alloy sheet to be lower, but the differential displacement density inside the third aluminum-magnesium alloy sheet is already very low when performing an annealing heat treatment of more than about 320 °C. Therefore, the hardness values of the third aluminum-magnesium alloy sheets subjected to the annealing heat treatment at about 320 ° C or higher are very close, so the hardness of the third aluminum-magnesium alloy sheet after the annealing heat treatment step at 320 ° C is defined as a reference in this embodiment. Lower limit of hardness.

In one embodiment, the annealing heat treatment step is performed at different temperatures to make the mechanical properties of the subsequently formed aluminum-magnesium alloy sheets for the anode different. In general, the higher the temperature of the annealing heat treatment step, the lower the strength and hardness of the aluminum-magnesium alloy sheet for the anode. Therefore, the annealing heat treatment step can adjust the strength and hardness of the aluminum-magnesium alloy sheet for the anode according to actual needs, in order to comply with the product. Requirements for strength, hardness, etc. required for different parts.

6. Perform the anodizing step

Subsequently, as shown in step 160, the third aluminum-magnesium alloy sheet is operated at 20 ° C, an operating voltage of 12.5 to 13.0 volts, an operating current of 3 amps, and An anodizing step was carried out in an electrolytic solution containing sulfuric acid having a concentration of 180 g/liter to form an aluminum-magnesium alloy sheet for an anode. The third aluminum-magnesium alloy sheet after the annealing heat treatment step of 150 ° C to less than 320 ° C and after the anodizing step has a color difference measurement value, and the third aluminum-magnesium alloy sheet after the annealing treatment step of 320 ° C and after the anode treatment step has The color difference reference value, and the third aluminum-magnesium alloy sheet can obtain the color difference relative value (Δb) from the following formula (II): the color difference relative value = the color difference measurement value - the color difference reference value (II).

Still another feature of the method of the present invention is that the third aluminum-magnesium alloy sheet obtained has better color uniformity after controlling the thickness reduction ratio of the cold rolling step and the relative poor discharge density of the annealing heat treatment step. In an embodiment, the relative value (Δb) of the color difference of the third aluminum-magnesium alloy sheet may be, for example, not more than 0.3.

In one embodiment, the above-mentioned color difference measurement value and color difference reference value are used according to a color space defined by the International Commission on Illumination (CIE) CIE 1976 L* a* b* (CIELAB). The standard, its three basic parameters (L*, a*, b*) indicate the brightness of the color (L*: L* = 0 indicates black, and L * = 100 indicates white), and the color is between red and green. The position (a* is a negative value indicates a trend toward green, while a positive value indicates a trend toward red) and the position of the color between yellow and blue (b* negative value indicates a trend toward blue, and a positive value indicates a trend toward yellow). The invention measures the above-mentioned color difference measurement value and color difference reference value by using a commercially available photometer, and the obtained data is divided by the color difference value (b*) in the CIE 1976 (L*a*b*) color difference formula. Analysis of the assessment.

In one embodiment, the color difference reference value is the color difference value of the third aluminum-magnesium alloy sheet after the annealing heat treatment step of 320 ° C and the anode treatment step. Since the color difference value and the difference density have a negative correlation, that is, the lower the difference density, the color difference value is smaller, and the appearance of the third aluminum-magnesium alloy sheet after the anodizing step tends to be blue. Therefore, in this embodiment, the third aluminum-magnesium alloy sheet after the annealing heat treatment step of 320 ° C and after the anode treatment step is used as the color difference reference value.

In addition, in other embodiments, before the above-mentioned anodizing step, the alkaline washing step may be further optionally included, wherein the temperature of the alkali washing step is 45° C., and the time of the alkali washing step is 5 minutes (min), the alkali washing liquid A sodium hydroxide caustic wash at a concentration of 50 g/liter.

It is worth mentioning that the aluminum-magnesium alloy sheet for anode obtained by the present invention is characterized in that the aluminum-magnesium alloy cast embryo is sequentially subjected to a homogenization heat treatment step, a hot rolling step, a cold rolling step, an annealing heat treatment step and an anodizing treatment. a step, and after the cold rolling step of the first aluminum-magnesium alloy sheet, the ratio of the thickness of the second aluminum-magnesium alloy sheet formed to be thinned, that is, the thickness reduction rate is not less than 60%, and in the third aluminum-magnesium alloy When the relative difference density of the sheets is required to be 0% to 90%, an aluminum-magnesium alloy sheet for anodes having a relative color difference of not more than 0.3 can be obtained. Therefore, according to the method for producing an aluminum-magnesium alloy sheet for an anode according to the present invention, the thickness reduction ratio after the cold rolling step is controlled to be not less than 60% in the process, and the relative difference in discharge density after the annealing heat treatment step is from 0% to 90%. %, it is possible to produce an aluminum-magnesium alloy sheet for an anode having an excellent difference in relative value of not more than 0.3, thereby improving the appearance color of the conventional aluminum-magnesium alloy for anode Yellowish or uneven.

The following is a few examples to illustrate in more detail the aluminum-magnesium alloy sheet for anode of the present invention and the method for producing the same, which are not intended to limit the present invention, and therefore the scope of protection of the present invention is to be seen in the appended claims. The definition is subject to change.

Example 1

First, an aluminum-magnesium alloy casting embryo is provided, wherein the aluminum-magnesium alloy casting embryo comprises 0.11% by weight of bismuth, 0.32% by weight of iron, less than 0.1% by weight of copper, less than 0.1% by weight of manganese, 2.47% by weight of magnesium, and 0.19 by weight. The percentage of chromium and less than 0.1 weight percent zinc, the balance being aluminum.

Then, the aluminum-magnesium alloy slab is subjected to a homogenization heat treatment step. The heating temperature of the above homogenization heat treatment step is 500 ° C to 530 ° C.

Next, after the homogenization heat treatment step, at least the hot rolling step of the aluminum-magnesium alloy casting embryo is further included to form the first aluminum-magnesium alloy sheet. The hot rolling temperature of the above treatment step is not less than 300 °C.

Thereafter, the first aluminum-magnesium alloy sheet described above was subjected to a cold rolling step to form a second aluminum-magnesium alloy sheet in which the thickness reduction amount was 82%.

Next, the second aluminum-magnesium alloy sheet is subjected to an annealing heat treatment step, wherein the annealing heat treatment step uses temperatures of 180 ° C, 250 ° C, and 320 ° C, respectively, to form three sets of third aluminum-magnesium alloys having different annealing temperatures. Sheet A1, third aluminum-magnesium alloy sheet A2, and third aluminum-magnesium alloy sheet A3.

Thereafter, an anode treatment step is performed on each of the three sets of the third aluminum-magnesium alloy sheets A1, the third aluminum-magnesium alloy sheets A2, and the third aluminum-magnesium alloy sheets A3. First, the third aluminum-magnesium alloy sheet is subjected to an alkali washing step using 50 gram/liter (g/L) of aluminum hydroxide (NaOH), wherein the temperature of the alkali washing step is 45 ° C, and the time of the alkali washing step is 5 minutes (min). Next, the anode treatment step is carried out using 180 g/liter (g/L) of sulfuric acid (H ₂ SO ₄ ), wherein the temperature of the anodizing step is 20 ° C, the current of the anodizing step is 3 amps (A), and the anodizing step The voltage is 12.5 to 13.0 volts (V) to obtain an aluminum-magnesium alloy sheet for the anode.

Examples 2 to 4

The manufacturing method of the first embodiment is different in the composition of the aluminum-magnesium alloy castings of the examples 2 to 4, and the process parameters of the homogenization heat treatment step, the hot rolling step, the thickness reduction ratio, the annealing heat treatment and the anode treatment, and the use thereof The quantities and process parameters are shown in Table 1.

Comparative Examples 1 to 4

The comparative example was produced in the same manner as the examples, wherein Comparative Examples 1 to 4 correspond to Comparative Examples 1 to 4, respectively, and Comparative Examples 1 to 4 and Examples 1 to 4 are respectively different in the process of the annealing steps of Comparative Examples 1 to 4. The parameters are different, and the composition, usage and process parameters are shown in Table 1.

Evaluation method

A plurality of performance tests were carried out on the aluminum-magnesium alloy sheets for the anodes of the examples and the comparative examples. The test items are as follows:

Relative differential density analysis

Examples 1 to 4 and Comparative Examples 1 to 4 were subjected to relative differential densitometric analysis tests. Briefly, the hardness of the aluminum-magnesium alloy sheets for the anodes of the examples and the comparative examples was analyzed by using the micro-hardness of Examples 1 to 4 and Comparative Examples 1 to 4, and then according to the formula. (I) Calculate the relative difference in densitometry.

Table 2 shows the results of the relative difference in the row density of the aluminum-magnesium alloy sheets for the anodes of the examples and the comparative examples, wherein the relative difference densities of Examples 1 to 4 were 0% to 90%, and the relatives of Comparative Examples 1 to 4 were relative. The difference in density is greater than 90% to 100%.

As can be seen from the test results of the second table, the relative difference densities of Examples 1 to 4 were less than 90% as compared with the relative difference densities of Comparative Examples 1 to 4.

2. Color difference test

The surface color difference measurement values were tested in Examples 1 to 4 and Comparative Examples 1 to 4. Briefly, the aluminum-magnesium alloy sheets for the anodes of Examples 1 to 4 and Comparative Examples 1 to 4 were subjected to color difference measurement using a commercially available spectrophotometer (Konica Minolta, model CM-2600d, Japan), and the obtained data was The CIE 1976 (L*a*b*) color difference formula was evaluated. The above steps of the spectrophotometer are carried out in accordance with the manufacturer's manual, which is not a problem here.

In the CIE 1976 (L*a*b*) color difference formula, the color difference of L* is the brightness of the surface color of the product. The larger the value, the brighter the color, and the darker the opposite. As for the color difference of a*, the color of the surface of the product is used to regulate the color of the product to be reddish or greenish. The larger the value, the more the color is biased toward red, and the more the color is greener. As for the color difference of b*, it is used to regulate the yellow or blue color of the surface of the product. The larger the value, the more the color is yellow, and the more the blue color.

2.1 color difference measurement (b*) test

Table 2 lists the results of the color difference measurement (b*) test of the aluminum-magnesium alloy sheets for anodes of the examples and the comparative examples.

As can be seen from the test results of the second table, the color difference measurement values (b*) of the examples 1 to 4 are relatively low with respect to the comparative examples 1 to 4, respectively, so that the aluminum-magnesium alloy sheets for the anodes of the examples 1 to 4 are relatively It is blue, which is less yellowish.

2.2 Calculate the relative value of color difference (△b)

The relative value of the color difference can be obtained by subtracting the color difference reference value from the aforementioned color difference measurement value. The second table lists the calculation results of the color difference relative values of the aluminum-magnesium alloy sheets for anodes of the examples and the comparative examples. As is apparent from the test results of the second table, the relative color difference values of Examples 1 to 4 were 0.3 or less, and the color difference relative values of Comparative Examples 1 to 4 were more than 0.3.

From the above results, it was found that the aluminum-magnesium alloy sheets for the anodes of Examples 1 to 4 were more uniform in color than Comparative Examples 1 to 4.

As can be seen from the above-described color difference test results, the color difference measurement value (b*) and the color difference value (Δb) of the examples are preferably better than the comparative examples.

In summary, it can be seen from the above performance test results that the embodiment of the present invention can have a better color difference measurement value (b*) and a color difference relative value (Δb) compared to the comparative example, and indeed achieve the present invention. purpose. However, Comparative Examples 1 to 4 cannot simultaneously have the above characteristics.

However, it should be added hereby that any one of ordinary skill in the art to which the present invention pertains should be readily understood that the aluminum-magnesium alloy sheet for anode of the present invention is merely illustrative, and other metal alloy materials may be used in other embodiments. Wait. This is well known to those of ordinary skill in the art to which the invention pertains and will not be further described.

In summary, it can be seen from the above embodiments of the present invention that the aluminum-magnesium alloy sheet for anodes of the present invention and the method for producing the same are used, and the aluminum-magnesium alloy sheets for anodes obtained are uniform in color and unbiased due to the method for producing the aluminum-magnesium alloy sheets for anodes. yellow. Furthermore, the aluminum-magnesium alloy sheet for anode obtained by the present invention has good both The color difference measurement value (b*) and the color difference value (Δb), and thus can have a uniform yellowishness.

While the present invention has been described above by way of example, it is not intended to be construed as a limitation of the scope of the invention. Therefore, the scope of the invention is defined by the scope of the appended claims.

100‧‧‧ method

110‧‧‧Provide the steps of casting aluminum-magnesium alloy

120‧‧‧Aluminum-magnesium alloy casting embryos are subjected to homogenization heat treatment steps

130‧‧‧Aluminum-magnesium alloy castings are subjected to a hot rolling step to form a first aluminum-magnesium alloy sheet

140‧‧‧The first aluminum-magnesium alloy sheet is subjected to a cold rolling step to form a second aluminum-magnesium alloy sheet

150‧‧‧A second aluminum-magnesium alloy sheet is subjected to an annealing heat treatment step to form a third aluminum-magnesium alloy sheet

160‧‧‧A third aluminum-magnesium alloy sheet is subjected to an anodizing step to form an aluminum-magnesium alloy sheet for the anode

Claims (8)

A method for manufacturing an aluminum-magnesium alloy sheet for an anode, comprising: providing an aluminum-magnesium alloy casting embryo, wherein the aluminum-magnesium alloy casting embryo comprises at least: 0% by weight to 0.25% by weight of bismuth; and 0% by weight to 0.7% by weight of iron 0 wt% to 0.1 wt% copper; 0 wt% to 0.1 wt% manganese; 0 wt% to 0.1 wt% zinc; 2.2 wt% to 2.8 wt% magnesium; 0.15 wt% to 0.35 wt% chromium And the remainder is aluminum and other unavoidable impurities; the aluminum-magnesium alloy casting embryo is subjected to a homogenization heat treatment step, wherein the homogenization heat treatment step is heated at a temperature of 500 ° C to 530 ° C; The aluminum-magnesium alloy casting embryo is subjected to a hot rolling step to form a first aluminum-magnesium alloy sheet, wherein the first aluminum-magnesium alloy sheet has a hot rolling thickness, and the hot rolling temperature of the hot rolling step is not less than 300 ° C; the first aluminum-magnesium alloy sheet is subjected to a cold rolling step to form a second aluminum-magnesium alloy sheet, wherein the second aluminum-magnesium alloy sheet has a thickness of the cold rolling and a reference hardness upper limit, the hot rolling thickness having a difference from the cold rolling thickness, and the ratio of the difference to the hot rolling thickness is not less than 60%; the second aluminum magnesium alloy The sheet is subjected to an annealing heat treatment step at 150 ° C to 320 ° C for 1 hour to 10 hours to obtain a third aluminum-magnesium alloy sheet, wherein the third aluminum after the annealing heat treatment step is performed at 150 ° C to less than 320 ° C The magnesium alloy sheet has an annealing hardness, and the third aluminum-magnesium alloy sheet has a reference hardness lower limit value after the annealing heat treatment step at 320 ° C, and the third aluminum-magnesium alloy sheet is obtained by the following formula (I) A relative difference in density (%) is 0% to 90%: relative difference in density (%) = (the annealing hardness - the lower limit of the reference hardness) / (the upper limit of the hardness reference - the lower limit of the reference hardness) ×100% (I); and an anodizing step of the third aluminum-magnesium alloy sheet, the anode treatment step being at an operating voltage of 20 ° C, 12.5 to 13.0 volts, an operating current of 3 amps, and a concentration of sulfuric acid Performing in one of 180 g/liter of the electrolyte, wherein the annealing step of 150 ° C to less than 320 ° C and the third aluminum-magnesium alloy sheet after the anodizing step have a color difference measurement value, which is 320 ° C The third aluminum-magnesium alloy sheet has an chromatic aberration reference value after the annealing treatment step, and the third aluminum-magnesium alloy sheet has a relative color difference value (Δb) obtained by the following formula (II). The color difference relative value (Δb) is not more than 0.3: the color difference relative value = the color difference measurement value - the color Difference reference value (II). The method for producing an aluminum-magnesium alloy sheet for an anode according to claim 1, wherein the heating temperature of the hot rolling step is 330 °C. The method for producing an aluminum-magnesium alloy sheet for an anode according to claim 1, wherein the ratio is 60% to 90%. The method for producing an aluminum-magnesium alloy sheet for an anode according to claim 1, wherein the hot-rolled thickness is 5 to 7 mm. The method for producing an aluminum-magnesium alloy sheet for an anode according to claim 1, wherein the cold-rolled thickness is 0.6 to 1 mm. The method for producing an aluminum-magnesium alloy sheet for an anode according to claim 1, wherein the homogenization heat treatment step has a duration of from 3 hours to 30 hours. The method for producing an aluminum-magnesium alloy sheet for an anode according to claim 1, wherein the aluminum-magnesium alloy casting body is formed by a casting molding step. An aluminum-magnesium alloy sheet for an anode obtained by the method according to any one of claims 1 to 7.