6063 aluminum alloy and extrusion process thereof

Abstract

The invention discloses a 6063 aluminum alloy and an extrusion process thereof, and belongs to the technical field of aluminum alloy manufacturing. The 6063 aluminum alloy comprises the following components in percentage by mass: 0.38 to 0.42 percent of Si, less than or equal to 0.16 percent of Fe, 0.54 to 0.58 percent of Mg, 0.03 percent of Cu, 0.03 percent of Cr, 0.01 percent of Ti and the balance of aluminum and inevitable impurities. The extrusion process comprises the following steps: S1, mixing and casting raw materials in proportion to obtain a cast ingot; s2, homogenizing, heating, extruding, quenching and cooling the cast ingot to obtain a blank; and S3, the blank is subjected to hot straightening, saw cutting and artificial aging, and the 6063 aluminum alloy is obtained. The strength and the extrusion efficiency of an aluminum alloy product are improved by carrying out proportion improvement design on chemical components of the 6063 aluminum alloy cast rod and carrying out optimization design on an extrusion process.

Description

Technical Field

[0001] The present invention belongs to the technical field of aluminum alloy manufacturing, and particularly relates to a 6063 aluminum alloy and its extrusion process. Background Art

[0002] The main alloying elements of 6063 aluminum alloy are magnesium and silicon, which have excellent processing performance, good weldability, extrudability and electroplating performance, good corrosion resistance, toughness, are easy to polish and color film, and have excellent anodic oxidation effect. It is a typical extrusion alloy and is widely used in building profiles, irrigation pipes, tubes, bars, and profiles for vehicles, racks, furniture, elevators, fences, etc.

[0003] 6063 aluminum alloy profiles have been widely used in many fields, and various specifications of profiles have been formed in the market. The requirements for components in the production of 6063 aluminum alloy profiles are relatively high. If the components are different, the performance of the produced profiles will also vary greatly. In addition, as a typical extrusion alloy, the level of its extrusion process will also have a great impact on the material quality. In the current prior art, the production and manufacturing process technology is not mature and perfect enough, and there are still certain defects, resulting in unqualified extrusion molding products and difficult to ensure the production quality of 6063 aluminum alloy profiles. Summary of the Invention

[0004] The purpose of the present invention is to provide a 6063 aluminum alloy and its extrusion process to solve the technical problem of incomplete homogenization in the process of preparing 6063 aluminum alloy profiles.

[0005] The purpose of the present invention can be achieved by the following technical solutions:

[0006] A 6063 aluminum alloy, the 6063 aluminum alloy includes the following components in mass percentage: Si 0.38 - 0.42%, Fe ≤ 0.16%, Mg 0.54 - 0.58%, Cu 0.03%, Cr 0.03%, Ti 0.01%, and the balance is aluminum and unavoidable impurities.

[0007] The present invention also provides an extrusion process for 6063 aluminum alloy, including the following steps:

[0008] S1. After mixing and melting the raw materials in proportion, an ingot is obtained;

[0009] S2. The ingot is homogenized, heated, extruded, quenched, and cooled to obtain a blank;

[0010] S3. The blank is hot straightened, sawed, and artificially aged to obtain 6063 aluminum alloy.

[0011] Further, the heating temperature in S2 is 480 - 500 °C.

[0012] Furthermore, during the extrusion process in S2, the heating temperature of the die is 470 - 485 °C, the temperature of the extrusion cylinder is 390 - 410 °C, and the temperature of the discharge port is 520 - 550 °C. If the temperature of the extrusion cylinder is too high, the tensile strength of the prepared 6063 aluminum alloy profile will decrease, and cracks will occur under the action of friction.

[0013] Furthermore, during the extrusion process in S2, the speed of the extrusion shaft is 2.0 - 2.5 mm / s; the extrusion ratio is 26 - 29. The extrusion ratio in S2 is controlled within 26 - 29. If the extrusion ratio is too low, it can be seen that the grains are elongated along the extrusion direction in the structure, and a small amount of recrystallized grains are found at the grain boundaries, and the alloy structure is unevenly distributed; if the extrusion ratio is too high, it will cause the die to bear too much pressure, resulting in die deformation, and a high extrusion ratio will make the metal flow more difficult, resulting in difficulty in ensuring the dimensions of the aluminum profile, and even blockage may occur, resulting in too low product yield, increasing production costs and energy consumption.

[0014] Furthermore, the temperature after quenching is 28 - 30 °C, and the quenching cooling rate > 260 °C / min.

[0015] Furthermore, the cooling method in S2 is spraying and water cooling. The cooling method of spraying plus water cooling can make the hardness and dimensional accuracy of the prepared aluminum profile better.

[0016] Furthermore, during the hot straightening process in S3, the elongation rate is 0.5 - 1.0%. The hot straightening can further correct the shape of the extruded aluminum alloy profile and improve the dimensional accuracy of the prepared aluminum alloy profile; and if the elongation rate is too large, it will cause positional tolerance and dimensional accuracy exceeding the standard of the prepared profile. The method of hot straightening and the setting of the elongation rate in the above technical solution can make the prepared aluminum alloy profile have good dimensional accuracy.

[0017] Furthermore, quality inspection is also included in the sawing in S3. Arrange quality inspection in a timely manner, and discover and handle other quality problems such as rough products, tearing, and slag inclusion in a timely manner.

[0018] Furthermore, the temperature of artificial aging in S3 is 160 - 165 °C, and the time is 6 - 8 h.

[0019] The beneficial effects of the present invention:

[0020] By improving the chemical composition ratio design of 6063 aluminum alloy cast rods and optimizing the extrusion process design, the present invention enhances the strength and extrusion efficiency of aluminum alloy products. The aluminum alloy products prepared by the preparation process in the present invention have high strength and high production efficiency, with a tensile strength of 230 - 250 MPa, a yield strength of 220 - 240 MPa, and an elongation of 14% - 17%, providing excellent aluminum alloy profiles for subsequent processing by customers.

[0021] In the present invention, the content of Si element is only 0.38 - 0.42%, and the mass ratio of Mg and Si elements < 1.53. The excess Si element helps to improve the casting performance and welding performance of the alloy and increases the tensile strength of the alloy. And in the extrusion process of the present invention, the addition of element zinc in the raw materials in the traditional process is abandoned, and no zinc element is added to the synthetic elements of the aluminum alloy in the present invention, thus avoiding the appearance of white spots and white line defects on the surface after oxidation of the aluminum alloy profiles, and helping to maintain the best mechanical properties and processing performance of 6063 alloy aluminum materials. Detailed implementation mode

[0022] Next, in combination with the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

[0023] Embodiment 1

[0024] An extrusion process for 6063 aluminum alloy, and the specific preparation steps are as follows:

[0025] S1. Mix and melt-cast according to the proportion of Si 0.38%, Fe 0.16%, Mg 0.54%, Cu 0.03%, Cr 0.03%, Ti 0.01%, with the balance being aluminum and unavoidable impurities to obtain an ingot;

[0026] S2. Homogenize, heat, extrude, quench the ingot, and cool it using spraying and water cooling to obtain a blank; among them, the heating temperature is 480 °C, the heating temperature of the mold during the extrusion process is 470 °C, the temperature of the extrusion cylinder is 390 °C, and the temperature of the discharge port is 520 °C; the temperature after quenching is 30 °C, and the quenching cooling rate is 280 °C / min; the extrusion shaft speed is 2.0 mm / s, and the extrusion ratio is 27.8;

[0027] S3. Heat straighten, saw cut, conduct quality inspection, and perform artificial aging on the blank to obtain 6063 aluminum alloy; among them, the elongation rate is 0.6%; among them, the artificial aging temperature is 160 °C and the time is 8 h.

[0028] Example 2

[0029] It is only different from Example 1 in that:

[0030] S1. Mix and melt cast Si 0.38%, Fe 0.16%, Mg 0.58%, Cu 0.03%, Cr 0.03%, Ti 0.01% in proportion, with the balance being aluminum and inevitable impurities to obtain an ingot; the remaining steps are the same as those in Example 1 to obtain 6063 aluminum alloy.

[0031] Example 3

[0032] It is only different from Example 1 in that:

[0033] S1. Mix and melt cast Si 0.42%, Fe 0.13%, Mg 0.54%, Cu 0.03%, Cr 0.03%, Ti 0.01% in proportion, with the balance being aluminum and inevitable impurities to obtain an ingot; the remaining steps are the same as those in Example 1 to obtain 6063 aluminum alloy.

[0034] Example 4

[0035] It is only different from Example 1 in that:

[0036] S2. Homogenize, heat, extrude, quench the ingot, and cool it using spraying and water cooling to obtain a blank; the heating temperature is 500°C, the die heating temperature during extrusion is 483°C, the extrusion barrel temperature is 408°C, and the outlet temperature is 540°C; the temperature after quenching is 30°C, and the quenching cooling rate is 300°C / min; the extrusion shaft speed is 2.5 mm / s, and the extrusion ratio is 27; the remaining raw materials and steps are the same as those in Example 1 to obtain 6063 aluminum alloy.

[0037] Example 5

[0038] It is only different from Example 1 in that:

[0039] S3. Thermally straighten, saw cut, conduct quality inspection, and perform artificial aging on the blank to obtain 6063 aluminum alloy; the elongation rate is 0.95%; the artificial aging temperature is 165°C, and the time is 8 h; the remaining raw materials and steps are the same as those in Example 1 to obtain 6063 aluminum alloy.

[0040] Comparative Example 1

[0041] It is only different from Example 1 in that element zinc is added to the raw material components:

[0042] S1. Mix and cast Si 0.38%, Fe 0.16%, Mg 0.54%, Cu 0.03%, Cr 0.03%, Ti 0.01%, Zn 0.01% in proportion, with the balance being aluminum and unavoidable impurities to obtain an ingot; the remaining steps are the same as those in Example 1.

[0043] Comparative Example 2

[0044] It is only different from Example 1 in that the content of Mg is different:

[0045] S1. Mix and cast Si 0.38%, Fe 0.16%, Mg 0.62%, Cu 0.03%, Cr 0.03%, Ti 0.01% in proportion, with the balance being aluminum and unavoidable impurities to obtain an ingot; the remaining steps are the same as those in Example 1.

[0046] Comparative Example 3

[0047] It is only different from Example 2 in that step S2 is different:

[0048] S2. Homogenize, heat, extrude, quench the ingot, and cool it using spraying and water cooling to obtain a blank; the heating temperature is 480°C, the die heating temperature during extrusion is 470°C, the extrusion cylinder temperature is 390°C, and the outlet temperature is 520°C; the temperature after quenching is 30°C, and the quenching cooling rate is 210°C / min; the extrusion shaft speed is 2.0 mm / s, and the extrusion ratio is 32; the remaining raw materials and steps are the same as those in Example 2.

[0049] Comparative Example 4

[0050] It is only different from Example 3 in that step S3 is different:

[0051] S3. Hot straighten, saw cut, perform quality inspection, and artificial aging on the blank to obtain 6063 aluminum alloy; the elongation rate is 1.2%; the artificial aging temperature is 180°C, and the time is 8 h. The remaining raw materials and steps are the same as those in Example 3.

[0052] Test the mechanical properties of the 6063 aluminum alloy profiles prepared in Examples 1 - 5 and Comparative Examples 1 - 4 according to the standard of GB / T 6892 - 2015 "Aluminum and Aluminum Alloy Extruded Profiles for General Industrial Use", and the test results are shown in Table 1:

[0053] Table 1

[0054] Project Tensile strength (MPa) Yield strength (MPa) Elongation (%) Example 1 238 226 17 Example 2 230 220 16 Example 3 249 235 14 Example 4 236 240 17 Example 5 250 229 16 Comparative Example 1 212 195 11 Comparative Example 2 210 189 10 Comparative Example 3 209 193 9 Comparative Example 4 213 192 10

[0055] As can be seen from Table 1, compared with Comparative Examples 1-4, the tensile strength of the 6063 aluminum alloy profiles prepared in Examples 1-5 is ≥230 MPa, the yield strength is ≥220 MPa, and the elongation is ≥14%. Thus, it can be seen that the 6063 aluminum alloy profiles prepared in the present invention have excellent mechanical properties and dimensional accuracy.

[0056] It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device.

[0057] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A 6063 aluminum alloy, characterized in that: The invention comprises the following components in percentage by mass: Si 0.38-0.42%, Fe ≤ 0.16%, Mg 0.54-0.58%, Cu 0.03%, Cr 0.03%, Ti 0.01%, and the balance is aluminum and unavoidable impurities.

2. An extrusion process for 6063 aluminum alloy as claimed in claim 1, characterized in that: The following steps are involved: S1, mixing the raw materials according to the proportion and melting and casting to obtain an ingot; S2, homogenizing, heating, extruding, quenching, and cooling the ingot to obtain a billet; S3. The blank is subjected to hot straightening, sawing and artificial aging to obtain 6063 aluminum alloy.

3. The extrusion process of 6063 aluminum alloy according to claim 2, characterized in that: The heating temperature in S2 is 480-500°C.

4. The extrusion process of 6063 aluminum alloy according to claim 2, characterized in that: During the extrusion process in S2, the mold heating temperature is 470-485°C, the extrusion barrel temperature is 390-410°C, and the discharge port temperature is 520-550°C.

5. The extrusion process of 6063 aluminum alloy according to claim 2, characterized in that: The extrusion shaft speed during the extrusion process in S2 is 2.0-2.5 mm / s.

6. The extrusion process of 6063 aluminum alloy according to claim 2, characterized in that: The temperature after quenching is 28-30°C, and the quenching cooling rate is >260°C / min.

7. The extrusion process of 6063 aluminum alloy according to claim 2, characterized in that: The cooling methods in S2 are spraying and water cooling.

8. The extrusion process of 6063 aluminum alloy according to claim 2, characterized in that: During the heat straightening process in S3, the elongation is 0.5-1.0%.

9. The extrusion process of 6063 aluminum alloy according to claim 2, characterized in that: S3 also includes quality inspection during sawing.

10. The extrusion process of 6063 aluminum alloy according to claim 2, characterized in that: The artificial aging temperature in S3 is 160-165°C and the time is 6-8h.