High-yield-ratio aluminum alloy rod and preparation method thereof

Abstract

The invention provides a high-yield-ratio aluminum alloy rod and a preparation method thereof, and belongs to the field of alloy material preparation. The preparation method of the high-yield-ratio aluminum alloy rod comprises the steps that a rolled aluminum alloy is sequentially subjected to homogenizing heat treatment, drawing treatment and aging treatment, and the high-yield-ratio aluminum alloy rod is obtained; the temperature of the homogenizing heat treatment is 535-565 DEG C, and the heat preservation time of the homogenizing heat treatment is 12-20 hours; the temperature of the aging treatment is 265-295 DEG C, and the heat preservation time of the aging treatment is 12-20 hours. According to the high-yield-ratio aluminum alloy rod prepared through the preparation method, the tensile strength ranges from 150 MPa to 190 MPa, the yield strength is larger than or equal to 140 MPa, the yield ratio is larger than or equal to 85%, the elongation is larger than or equal to 18%, and meanwhile the high yield ratio and the high elongation are achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of alloy material preparation, in particular to a high yield ratio aluminum alloy rod and a preparation method thereof. BACKGROUND

[0002] With the continuous promotion of automobile light weight, aluminum alloy materials have been widely used in the field of automobile manufacturing. High yield ratio aluminum alloy is a popular material in the field of aluminum alloy processing at home and abroad.

[0003] At present, the production process steps of domestic aluminum alloy rod are generally as follows: alloy smelting preparation-vertical shaft casting aluminum alloy round ingot-homogenization heat treatment-round ingot extrusion into rod. However, the production process of the aluminum alloy rod still has the following disadvantages: the unevenness of the structure of the round ingot edge and the core, which leads to poor uniformity of the performance of the extruded aluminum alloy; the yield ratio of the aluminum alloy rod produced by the round ingot extrusion technology is low, and the yield ratio is lower than 85%, which cannot meet the requirements of high yield ratio at present. SUMMARY

[0004] The purpose of the present application is to provide a high yield ratio aluminum alloy rod and a preparation method thereof. The preparation method provided by the present application can prepare an aluminum alloy rod with high yield ratio and high elongation.

[0005] In order to achieve the above-mentioned purpose of the application, the present application provides the following technical scheme:

[0006] The present application provides a preparation method of a high yield ratio aluminum alloy rod, comprising:

[0007] The as-rolled aluminum alloy is sequentially subjected to homogenization heat treatment, drawing treatment and aging treatment to obtain a high yield ratio aluminum alloy rod;

[0008] The temperature of the homogenization heat treatment is 535-565℃, and the holding time of the homogenization heat treatment is 12-20h;

[0009] The temperature of the aging treatment is 265-295℃, and the holding time of the aging treatment is 12-20h.

[0010] Preferably, the rate of temperature rise to the homogenization heat treatment temperature is 2.5-9℃ / min.

[0011] Preferably, the total deformation amount in the radial direction during the drawing treatment is 10-40%.

[0012] Preferably, the number of passes of the drawing treatment is 1-4 times.

[0013] Preferably, the number of passes of the drawing treatment is 1 time, and the deformation amount in the radial direction during the drawing treatment is 10-13%.

[0014] Preferably, the drawing process is performed twice, with the radial deformation of the first drawing process being 10-13% and the radial deformation of the second drawing process being 9-10%.

[0015] Preferably, the drawing process is performed in three passes, with the radial deformation of the first pass being 10-13%, the radial deformation of the second pass being 9-10%, and the radial deformation of the third pass being 15-16%.

[0016] Preferably, the drawing process is performed in four passes, with the radial deformation of the first pass being 10-13%; the radial deformation of the second pass being 9-10%; the radial deformation of the third pass being 15-16%; and the radial deformation of the fourth pass being 2-3%.

[0017] Preferably, the rate of heating to the aging treatment temperature is 2.5 to 4 °C / min.

[0018] The present invention also provides a high yield strength ratio aluminum alloy rod prepared by the preparation method described above, wherein the high yield strength ratio aluminum alloy rod has a tensile strength of 150-190 MPa, a yield strength ≥140 MPa, a yield strength ratio ≥85%, and an elongation ≥18%.

[0019] This invention provides a method for preparing a high yield strength ratio aluminum alloy rod, comprising: subjecting rolled aluminum alloy sequentially to homogenization heat treatment, drawing treatment, and aging treatment to obtain a high yield strength ratio aluminum alloy rod; the homogenization heat treatment temperature is 535-565℃, and the holding time is 12-20h; the aging treatment temperature is 265-295℃, and the holding time is 12-20h. This invention improves the yield strength ratio of the aluminum alloy rod by subjecting the rolled aluminum alloy to homogenization heat treatment and adjusting the temperature and time of the homogenization heat treatment to ensure uniform microstructure distribution in the aluminum alloy; the drawing treatment improves the strength and toughness of the aluminum alloy, further increasing the yield strength ratio; and the aging treatment, with adjusted temperature and time, improves the strength and hardness of the aluminum alloy while maintaining good toughness, further increasing the yield strength ratio of the aluminum alloy rod. The results of the examples show that the high yield strength ratio aluminum alloy rod prepared by the preparation method provided by the present invention has a tensile strength of 150-190 MPa, a yield strength ≥140 MPa, a yield strength ratio ≥85%, and an elongation ≥18%, and has both a high yield strength ratio and a high elongation. Attached Figure Description

[0020] Figure 1 This is a flowchart illustrating the preparation method of a high yield strength ratio aluminum alloy rod in an embodiment of the present invention. Detailed Implementation

[0021] This invention provides a method for preparing a high yield strength ratio aluminum alloy rod, comprising:

[0022] The rolled aluminum alloy was subjected to homogenization heat treatment, drawing treatment and aging treatment in sequence to obtain an aluminum alloy rod with high yield strength ratio.

[0023] In this invention, the aluminum alloy is preferably 6056 aluminum alloy. In this invention, the rolled aluminum alloy is preferably a continuously cast and rolled aluminum alloy.

[0024] In this invention, the homogenization heat treatment is preferably carried out in a homogenization furnace; the temperature of the homogenization heat treatment is 535–565°C, preferably 540–555°C, and more preferably 550°C; the holding time of the homogenization heat treatment is 12–20 h, preferably 12–18 h, and more preferably 12–15 h. By limiting the temperature and time of the homogenization heat treatment to the above ranges, this invention can ensure a uniform microstructure distribution in the aluminum alloy, which is beneficial for improving the yield strength ratio of the aluminum alloy rod.

[0025] In this invention, the rate of heating to the homogenization heat treatment temperature is preferably 2.5–9 °C / min, more preferably 3–6 °C / min, and even more preferably 3–4 °C / min. Limiting the heating rate to the homogenization heat treatment temperature to the above range ensures uniform heating of the aluminum alloy, which is beneficial for subsequent homogenization heat treatment.

[0026] In this invention, the cooling rate of the homogenization heat treatment is preferably 10–30 °C / h, more preferably 20–30 °C / h, and even more preferably 25 °C / h. Limiting the cooling rate of the homogenization heat treatment to the above range allows the alloy to possess good mechanical properties.

[0027] The present invention does not impose any special limitation on the cooling method of the homogenization heat treatment, as long as the cooling rate of the homogenization heat treatment is 10 to 30 °C / h.

[0028] In one embodiment of the present invention, the drawing process can be performed in a drawing machine; the total radial deformation during the drawing process can be 10-40%, 12.5-35%, 12.5-34%, or 20-30%. By limiting the total radial deformation during the drawing process to the above range, the present invention can obtain aluminum alloys of various sizes while ensuring that the aluminum alloys have good microstructure and mechanical properties.

[0029] In one embodiment of the present invention, the number of drawing passes can be 1 to 4, 1 to 3, or 1 to 2. By limiting the number of drawing passes to the above range, the present invention can obtain aluminum alloy rods of various sizes while ensuring that the aluminum alloy rods have good microstructure and mechanical properties.

[0030] In one embodiment of the present invention, the number of passes in the drawing process is 1, and the radial deformation of the drawing process can be 10-13%, or even 12.5%.

[0031] In one embodiment of the present invention, the drawing process is performed twice. The radial deformation of the first drawing process can be 10-13%, or even 12.5%; the radial deformation of the second drawing process can be 9-10%, or even 9.5%.

[0032] In one embodiment of the present invention, the drawing process is performed in three passes. The radial deformation of the first drawing pass can be 10-13%, or even 12.5%; the radial deformation of the second drawing pass can be 9-10%, or even 9.5%; and the radial deformation of the third drawing pass can be 15-16%, or even 15.8%.

[0033] In one embodiment of the present invention, the drawing process is performed in four passes. The radial deformation of the first drawing pass can be 10-13%, or even 12.5%; the radial deformation of the second drawing pass can be 9-10%, or even 9.5%; the radial deformation of the third drawing pass can be 15-16%, or even 15.8%; and the radial deformation of the fourth drawing pass can be 2-3%, or even 2.5%.

[0034] By limiting the radial deformation of each drawing pass to the above-mentioned range, this invention ensures that the aluminum alloy rod has good strength and hardness while maintaining good toughness.

[0035] In this invention, the aging treatment is preferably carried out in an aging furnace; the temperature of the aging treatment is 265–295°C, preferably 270–290°C, and more preferably 280°C; the holding time of the aging treatment is 12–20 h, preferably 12–18 h, and more preferably 12–15 h. By limiting the temperature and time of the aging treatment to the above ranges, this invention can improve the strength and hardness of the aluminum alloy rod while maintaining its good toughness, further improving the yield strength ratio of the aluminum alloy rod.

[0036] In this invention, the rate of heating to the aging treatment temperature is preferably 2.5–5 °C / min, more preferably 3.5–4.5 °C / min. Limiting the rate of heating to the aging treatment temperature to the above range allows for more uniform heat transfer to the interior of the alloy.

[0037] In this invention, the preferred cooling method for the aging process is air cooling.

[0038] This invention improves the yield strength ratio of aluminum alloy rods by homogenizing the rolled aluminum alloy under heat treatment and adjusting the temperature and time of the homogenization heat treatment to make the microstructure of the aluminum alloy uniform. The strength and toughness of the aluminum alloy are improved by drawing treatment, which further improves the yield strength ratio of the aluminum alloy rods. The strength and hardness of the aluminum alloy are improved by aging treatment and adjusting the temperature and time of aging treatment, while maintaining good toughness of the aluminum alloy, which further improves the yield strength ratio of the aluminum alloy rods.

[0039] The present invention also provides a high yield strength ratio aluminum alloy rod prepared by the preparation method described above, wherein the high yield strength ratio aluminum alloy rod has a tensile strength of 150-190 MPa, a yield strength ≥140 MPa, a yield strength ratio ≥85%, and an elongation ≥18%.

[0040] In a specific embodiment of the present invention, the flowchart of the preparation method of the high yield strength ratio aluminum alloy rod is as follows: Figure 1 As shown:

[0041] from Figure 1 As can be seen from the above, the preparation process of the high yield strength ratio aluminum alloy rod is as follows: the rolled aluminum alloy is subjected to homogenization heat treatment in a homogenizing furnace, then drawn in a drawing machine, and then aged in an aging furnace to obtain the high yield strength ratio aluminum alloy (high yield strength ratio aluminum alloy rod).

[0042] The technical solutions of this invention will be clearly and completely described below with reference to the embodiments thereof. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0043] Example 1

[0044] A method for preparing a high yield strength ratio aluminum alloy rod:

[0045] A 12mm diameter 6056 aluminum alloy (cast-rolled 6056 aluminum alloy) was heated to 550℃ in a homogenizing furnace at a rate of 6.1℃ / min, held at 550℃ for 12h, and then cooled to 50℃ at a rate of 25℃ / h. The homogenized heat-treated aluminum alloy was then subjected to a single-pass drawing process with a radial deformation of 12.5% ​​(resulting in an aluminum alloy with a diameter of 10.5mm). Subsequently, the alloy was heated to 280℃ in an aging furnace at a rate of 3.8℃ / min, held at 280℃ for 12h, and then air-cooled to room temperature to obtain a high yield strength ratio aluminum alloy rod.

[0046] The high yield strength ratio aluminum alloy rod obtained in Example 1 was tested for mechanical properties using an electronic universal testing machine. The test data are shown in Table 1.

[0047] Table 1. Mechanical property test data of the high yield strength ratio aluminum alloy rod obtained in Example 1.

[0048]

[0049] Example 2

[0050] A method for preparing a high yield strength ratio aluminum alloy rod:

[0051] A 12mm diameter 6056 aluminum alloy (cast-rolled 6056 aluminum alloy) was heated to 550℃ in a homogenizing furnace at a rate of 6.1℃ / min, held at 550℃ for 12h, and then cooled to 50℃ at a rate of 25℃ / h. The homogenized heat-treated aluminum alloy was then subjected to four drawing processes. The total radial deformation during the drawing process was 35% (the final diameter of the aluminum alloy was 7.8mm), and the radial deformation of the first drawing process was 12.5% ​​(the diameter of the aluminum alloy obtained was 10mm). The first pass of the aluminum alloy was 5mm thick. The radial deformation of the second pass was 9.5% (the diameter of the resulting aluminum alloy was 9.5mm). The radial deformation of the third pass was 15.8% (the diameter of the resulting aluminum alloy was 8mm). The radial deformation of the fourth pass was 2.5% (the diameter of the resulting aluminum alloy was 7.8mm). Then, the aluminum alloy was heated to 280℃ in an aging furnace at a rate of 3.8℃ / min and held at 280℃ for 12 hours. After the holding period, the aluminum alloy was air-cooled to room temperature to obtain a high yield strength ratio aluminum alloy rod.

[0052] The high yield strength ratio aluminum alloy rod obtained in Example 2 was tested for mechanical properties using an electronic universal testing machine. The test data are shown in Table 2.

[0053] Table 2. Mechanical property test data of the high yield strength ratio aluminum alloy rod obtained in Example 2.

[0054]

[0055] Comparative Example 1

[0056] The only difference between Comparative Example 1 and Example 1 is that the homogenization heat treatment temperature is 500°C; otherwise, they are the same as in Example 1.

[0057] The aluminum alloy rod obtained in Comparative Example 1 was subjected to mechanical property testing using an electronic universal testing machine. The test data are shown in Table 3.

[0058] Table 3 shows the mechanical property test data of the aluminum alloy rod obtained in Comparative Example 1.

[0059]

[0060] Comparative Example 2

[0061] The only difference between Comparative Example 2 and Example 1 is that the aging treatment temperature is 200°C; otherwise, they are the same as Example 1.

[0062] The aluminum alloy rod obtained in Comparative Example 2 was subjected to mechanical property testing using an electronic universal testing machine. The test data are shown in Table 4.

[0063] Table 4 shows the mechanical property test data of the aluminum alloy rod obtained in Comparative Example 2.

[0064]

[0065] As can be seen from the data in Tables 1 to 4, the method of the present invention can produce aluminum alloy rods with a tensile strength of 150-190 MPa, a yield strength ≥140 MPa, a yield-to-tensile ratio ≥85%, and an elongation ≥18%, while also exhibiting a high yield-to-tensile ratio and a high elongation.

[0066] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing a high yield strength ratio aluminum alloy rod, comprising: A high yield strength ratio aluminum alloy is obtained by sequentially subjecting rolled aluminum alloy to homogenization heat treatment, drawing treatment and aging treatment. The homogenization heat treatment temperature is 535–565℃, and the holding time for the homogenization heat treatment is 12–20 h; The aging treatment temperature is 265–295℃, and the aging treatment holding time is 12–20 hours.

2. The preparation method according to claim 1, characterized in that, The rate of heating to the homogenization heat treatment temperature is 2.5–9 °C / min.

3. The preparation method according to claim 1, characterized in that, The total radial deformation during the drawing process is 10% to 40%.

4. The preparation method according to claim 1 or 3, characterized in that, The number of pull-out processes is 1 to 4.

5. The preparation method according to claim 4, characterized in that, The drawing process is performed once, and the radial deformation is 10-13%.

6. The preparation method according to claim 4, characterized in that, The drawing process is performed in two passes. The radial deformation in the first pass is 10-13%, and the radial deformation in the second pass is 9-10%.

7. The preparation method according to claim 4, characterized in that, The drawing process is performed in three passes. The radial deformation in the first pass is 10-13%; the radial deformation in the second pass is 9-10%; and the radial deformation in the third pass is 15-16%.

8. The preparation method according to claim 4, characterized in that, The drawing process is performed in four passes. The radial deformation in the first pass is 10-13%; the radial deformation in the second pass is 9-10%; the radial deformation in the third pass is 15-16%; and the radial deformation in the fourth pass is 2-3%.

9. The preparation method according to claim 1, characterized in that, The rate of heating to the aging treatment temperature is 2.5–4 °C / min.

10. The high yield strength ratio aluminum alloy rod prepared by the method according to any one of claims 1 to 9, characterized in that, The high yield strength aluminum alloy has a tensile strength of 150-190 MPa, a yield strength ≥140 MPa, a yield ratio ≥85%, and an elongation ≥18%.

Images