TW201817893A - Aluminum-magnesium alloy manufacturing method - Google Patents

Abstract

An aluminum-magnesium alloy manufacturing method includes the following steps. A casting aluminum alloy raw material containing magnesium weight percentage of 4.00 wt% to 6.00 wt%, copper weight percentage of 0.20 wt% to 0.70 wt%, zinc weight percentage of 0.50 wt% to 2.50 wt%, manganese weight percentage of 0.15 wt% 0.50 wt%, iron weight percentage of 0.05 wt% to 0.35 wt% and silicon weight percentage of 0.05 wt.% to 0.20 wt% is prepared. The raw material is poured into a mold. The mold-casting material is hot-pressed into an aluminum roll at a temperature ranging 300 to 500 DEG C. After the aluminum roll is cooled to room temperature, a cold-rolling is then applied. Annealing the aluminum roll at an annealing temperature of 450 to 580 DEG C. The aluminum coil is manually aged at a constant temperature between 100 and 200 DEG C.

Description

 Aluminum-magnesium alloy manufacturing method  

The present invention relates to a method for producing an aluminum-magnesium alloy, and more particularly to a method for producing an aluminum-magnesium alloy which delays the appearance of Type B tensile strain marks.

The conventional aluminum-magnesium alloy is a work hardening type alloy, and its fully annealed material has excellent ductility, but due to the magnesium content, Type B tensile strain marks are easily induced in the subsequent forming process. This phenomenon is reflected in the tensile stress-strain curve, which is a stepped shape in which the curve begins to undergo a large volt, while the product surface is accompanied by parallel streaks where undulations begin to appear. Therefore, if the timing of the occurrence of Type B tensile strain marks can be delayed, it will help to expand the forming range without the Type B tensile strain marks, so that Type B tensile strain marks will not occur during forming.

In order to delay the timing of the beginning of the Type B tensile strain marks in the aluminum-magnesium alloy system, the conventional techniques utilize the method of increasing the grain size or reducing the magnesium content. However, although the above method is effective, it will be accompanied by the ductility of the material. With a drop in strength.

In view of the above problems, the industry still needs to develop other better aluminum-magnesium alloy manufacturing methods to delay the timing of Type B tensile strain marks.

Accordingly, it is an object of the present invention to provide a method of making an aluminum-magnesium alloy that delays the appearance of Type B tensile strain marks.

According to the above object of the present invention, a method for producing an aluminum-magnesium alloy is provided which comprises the following steps. The content of magnesium containing magnesium is 4.00 wt% to 6.00 wt%, the weight percentage of copper is 0.20 wt% to 0.70 wt%, the weight percentage of zinc is 0.50 wt% to 2.50 wt%, and the weight percentage of manganese is 0.15 wt%. The molten aluminum alloy raw material is 0.50 wt%, the weight percentage of iron is 0.05 wt% to 0.35 wt%, and the weight percentage of niobium is 0.05 wt% to 0.20 wt%. The aluminum alloy material is cast to form an aluminum billet. Between 300 and 500 ° C, the aluminum billet is hot rolled to form an aluminum coil. After the aluminum billet is cooled to room temperature, it is then subjected to cold rolling. The aluminum coil is annealed at an annealing temperature of 450 to 580 °C. The aluminum coil is artificially aged at a constant temperature between 100 and 200 ° C.

According to an embodiment of the invention, the cold rolling of the cold rolling is between 50 and 70%.

According to an embodiment of the present invention, the aluminum coil is cooled by the coiling method to achieve the effect of prolonging the low temperature artificial aging.

According to an embodiment of the present invention, after the aluminum coil is annealed, the aluminum coil is quenched to a normal temperature by water quenching, and then reheated to a temperature at which artificial aging is performed.

According to an embodiment of the present invention, the aluminum blank is further placed in a preheating furnace at 450 to 500 ° C for at least two hours, and then hot rolled.

According to an embodiment of the invention, the aluminum coil is artificially aged at 120 ° C for 2 hours.

According to an embodiment of the invention, the aluminum coil is artificially aged at 170 ° C for 2 hours.

By applying the method of adding a trace amount of a specific alloying element, the aluminum-magnesium alloy has a characteristic of a heat-treated alloy (Al-Cu or Al-Zn-Mg series alloy), and thus can be artificially reused in a low-temperature manner after annealing and cooling. The aging effect, by the fine secondary phase precipitated in the process, achieves the effect of delaying the appearance of Type B tensile strain marks.

The above and other objects, features, advantages and embodiments of the present invention will become more <RTIgt; A stress-strain curve; and [Fig. 2] is a photographic example showing the Type B tensile strain marks described in the present application.

The flow of the aluminum-magnesium alloy manufacturing method for delaying the occurrence of Type B tensile strain marks of the present invention basically comprises a preparation step, a casting molding step, a hot rolling step, a cold rolling step, an annealing step and an artificial aging step.

In this embodiment, the preparation step is to add 0.40 wt% to 6.00 wt% of magnesium (Mg) element, 0.20 wt% to 0.70 wt% of copper (Cu) element, and 0.50 wt% to 2.50 wt% by weight. % zinc (Zn) element, 0.15 wt% to 0.50 wt% manganese (Mn) element, 0.05 wt% to 0.35 wt% iron (Fe) element, weight percentage 0.05 wt% to 0.20 wt% The bismuth (Si) element is melted in the aluminum raw material in the equilibrium amount to prepare a molten aluminum alloy material, so that the characteristics of the heat-treated alloy (Al-Cu or Al-Zn-Mg series alloy) are slightly obtained. .

Next, a casting molding step is carried out to form an aluminum billet by casting the aluminum alloy raw material obtained in the molten state obtained in the preparation step.

The aluminum billet is then subjected to a hot rolling step, wherein the aluminum billet obtained by the casting step is placed in a preheating furnace at a temperature of 450 ° C to 500 ° C for at least two hours, and then rolled into a hot rolling mill for rolling. . The working temperature of the hot rolling process is maintained at 300 ° C ~ 500 ° C, and then coiled into an aluminum coil after rolling.

The cold rolling step is to start the cold rolling after the temperature of the aluminum coil obtained by the hot rolling step is lowered to room temperature, and the cold rolling elongation is controlled to be between 50 and 70% to avoid the subsequent annealing process. The cold storage energy is insufficient, causing the grains generated during annealing to be too coarse and affecting the strength and the poor ductility.

Subsequently, an annealing step is performed to anneal the aluminum coil obtained by the cold rolling step, and the annealing temperature is selected between 450 ° C and 580 ° C, and then quenched to room temperature by water quenching.

Finally, an artificial aging step is performed, which reheats the aluminum coil material to a temperature between 100 ° C and 200 ° C of aluminum material, and cools by coiling to achieve the effect of prolonging low temperature artificial aging, and finally obtains a delayed type B tensile strain gauge. Aluminium-magnesium alloy sheet appeared.

The following are examples of the conventional comparative examples and the aluminum-magnesium alloy sheets of the present invention having retarded Type B tensile strain marks, the alloy compositions of which are detailed as follows: AA5182 aluminum alloy of the conventional comparative example: magnesium (Mg) content is 4.5 wt% The iron (Fe) content is 0.26 wt%, the cerium (Si) content is 0.13 wt%, the manganese (Mn) content is 0.2 wt%, the copper (Cu) content is 0.02 wt, and the balance is aluminum.

The alloy composition of the invention has the alloy composition of: magnesium (Mg) content of 4.5 wt%, iron (Fe) content of 0.25 wt%, cerium (Si) content of 0.12 wt%, manganese (Mn) content of 0.45 wt%, The copper (Cu) content was 0.53 wt%, the zinc (Zn) content was 0.9 wt%, and the balance was aluminum.

The alloy composition of the invention has the alloy composition of: magnesium (Mg) content of 5.5 wt%, iron (Fe) content of 0.28 wt%, cerium (Si) content of 0.15 wt%, manganese (Mn) content of 0.35 wt%, The copper (Cu) content was 0.37 wt%, the zinc (Zn) content was 2.1 wt%, and the balance was aluminum.

The alloy compositions of the conventional comparative examples and the examples of the present invention are listed in Table 1:  

Through the above-mentioned manufacturing method, a comparative example and an embodiment of the present invention (ie, A alloy and B alloy) are subjected to "general annealing" or "annealing + artificial aging of the present invention (including aging treatment at two temperatures). The relationship between the strength of 2 hours) and the critical strain (ε _C ) at which Type B tensile strain marks occur is listed in Table 2 below:

Please refer to [FIG. 1], which is a graph showing tensile stress-strain curves according to an embodiment of the present invention. This figure is a comparative example of the tensile stress-strain curve of the comparative example, the A alloy, and the B alloy obtained in the above Table 2, after the conditions of "annealing and artificial aging 170 ° C for 2 hours" were applied. The parameter ε _C indicates the amount of stretch (%) when the "Type B stretch strain" first appears. The "arrow" corresponding to each curve indicates the position of ε _C , that is, the amount of stretch (%) when the "Type B stretch strain" first appears.

It can be seen from the above FIG. 1 and Table 2 that the aluminum-magnesium (Al-Mg) alloy system of the conventional comparative example does not have the effect of aging precipitation (ie, after artificial aging, the lodging strength and ε _C are not significantly improved. However, the method for manufacturing an aluminum-magnesium alloy which delays Type B tensile strain marks disclosed in the present invention is artificially aged after the annealing process, and can be delayed by utilizing the fine secondary phase precipitated during the low-temperature artificial aging process. Type B stretch strain marks appear. If the A alloy is used for processing, not only does its fall strength increase (for example, 178 MPa in Table 2), but also does not produce Type B tensile strain marks when the stretch width is less than 3.30% (anneal + artificial aging 170 ° C). . If the B alloy is used for processing, the drop strength can be as high as 216 MPa, and when the stretch is less than 8.15% (anneal + artificial aging 170 ° C), Type B tensile strain marks are not generated.

Please refer to [Fig. 2], which shows a photographic example of the Type B stretch strain marks described in this case, which is convenient for understanding the strain marks. The "two arrows" in the figure indicate the direction of the applied force of the stretching, and the Type B tensile strain marks are the parallel stripes in the photograph. In the technical field, there is another extension strain gauge called "Type A", but it is not a problem to be treated by the present invention, so that information on Type A tensile strain marks is not provided.

By applying the method for manufacturing an aluminum-magnesium alloy according to the present invention, the aluminum-magnesium alloy is slightly characterized by a heat-treated alloy (Al-Cu or Al-Zn-Mg series alloy) by adding a trace amount of a specific alloying element, and thus can be cooled after annealing. The artificial aging is carried out by the low temperature method, and the effect of delaying the appearance of the Type B tensile strain marks is achieved by the fine secondary phase precipitated in the process.

While the invention has been described above in terms of several embodiments, it is not intended to limit the scope of the invention, and the invention may be practiced in various embodiments without departing from the spirit and scope of the invention. The scope of protection of the present invention is defined by the scope of the appended claims.

Claims (7)

 A method for producing an aluminum-magnesium alloy, comprising: preparing a magnesium-containing weight percentage of 4.00 wt% to 6.00 wt%, a copper-containing weight percentage of 0.20 wt% to 0.70 wt%, and a zinc-containing weight percentage of 0.50 wt% to 2.50 wt%, a molten aluminum alloy raw material having a weight percentage of manganese of 0.15 wt% to 0.50 wt%, a weight percentage of iron containing 0.05 wt% to 0.35 wt%, and a weight percentage of niobium containing 0.05 wt% to 0.20 wt%; casting the aluminum alloy raw material Forming an aluminum billet; between 300 and 500 ° C, hot rolling the aluminum billet to form an aluminum coil; after the aluminum billet is cooled to room temperature, followed by cold rolling; at an annealing temperature of 450~ The aluminum coil is annealed between 580 ° C; and the aluminum coil is artificially aged at a constant temperature between 100 and 200 ° C.    The method for producing an aluminum-magnesium alloy according to claim 1, wherein the cold rolling amount of the cold rolling is between 50% and 70%.    The method for manufacturing an aluminum-magnesium alloy according to claim 1, wherein the aluminum coil is cooled by coiling to achieve an effect of prolonging low-temperature artificial aging.    The method for producing an aluminum-magnesium alloy according to claim 1, further comprising quenching the aluminum coil by a water quenching method to a normal temperature, and then reheating to a temperature at which artificial aging is performed.    The method for producing an aluminum-magnesium alloy according to claim 1, further comprising placing the aluminum billet in a preheating furnace at 450 to 500 ° C for at least two hours, and then performing hot rolling.    The method for producing an aluminum-magnesium alloy according to claim 1, wherein the aluminum coil is artificially aged at 120 ° C for 2 hours.    The method for producing an aluminum-magnesium alloy according to claim 1, wherein the aluminum coil is artificially aged at 170 ° C for 2 hours.