Homogenizing method for Al-Cu-Mg-Ag series aluminum alloy cast ingot

Abstract

The invention provides a homogenization method of an Al-Cu-Mg-Ag series aluminum alloy cast ingot, which comprises the following steps: carrying out homogenization treatment on the Al-Cu-Mg-Ag series aluminum alloy cast ingot to obtain a homogenized cast ingot; the homogenization treatment comprises first-stage heating, first-stage heat preservation, second-stage heating, second-stage heat preservation, third-stage heating and third-stage heat preservation which are sequentially carried out. According to the homogenization treatment of the Al-Cu-Mg-Ag series aluminum alloy cast ingot, the first-stage heating, the first-stage heat preservation, the second-stage heating, the second-stage heat preservation, the third-stage heating and the third-stage heat preservation which are sequentially carried out are adopted, compound aggregation is effectively reduced through the multi-stage heating and multi-stage heat preservation, and finally the mechanical property of aluminum alloy is improved.

Description

Technical Field

[0001] The invention relates to the technical field of aluminum alloy ingots, and in particular to a homogenization method for Al-Cu-Mg-Ag aluminum alloy ingots. Background Art

[0002] At present, the brake wheel hubs of various military and civilian aircraft in the world generally use 2XXX aluminum alloys without precious metals. However, conventional 2XXX aluminum alloys have poor heat resistance and are difficult to be welded to the diameter of the alloy. The large-size 2 series high-strength and high-heat-resistant deformable aluminum alloy round ingots are difficult to form. No domestic company has successfully produced them, and they are in a blank stage.

[0003] In order to meet the stringent application requirements of aircraft wheels, such as high load-bearing capacity, high operating temperature, long service life, safety and reliability, it is urgent to carry out research on the composition design and casting technology of new high-strength and heat-resistant 2XXX aluminum alloys.

[0004] Compared with the traditional 2XXX aluminum alloy for aircraft wheels, the new high-strength and heat-resistant Al-Cu-Mg-Ag aluminum alloy has superior comprehensive performance in strength, high-temperature performance, fracture toughness, fatigue and stress corrosion, and is similar to the 2XXX aluminum alloy in comprehensive corrosion resistance and stiffness. At present, the aircraft wheels made of this alloy have been used in various types of large military and civilian aircraft, and have achieved good results. However, due to the great tendency to form hot cracks and cold cracks, it is very difficult to form; and with the increase of precious metal Ag, the difficulty of forming increases geometrically. The applicant has achieved mass production of ingots, but it also contains a large number of compounds, which also affect the performance of the alloy. Therefore, a homogenization method for Al-Cu-Mg-Ag aluminum alloy ingots is provided to meet the requirements of high-strength and heat-resistant performance. Summary of the invention

[0005] The technical problem solved by the present invention is to provide a method for homogenizing an Al-Cu-Mg-Ag aluminum alloy ingot. The homogenization method provided by the present application can reduce the compound ratio of the ingot and ultimately improve the mechanical properties of the aluminum alloy.

[0006] In view of this, the present application provides a method for homogenizing an Al-Cu-Mg-Ag aluminum alloy ingot, comprising the following steps:

[0007] The Al-Cu-Mg-Ag aluminum alloy ingot is homogenized to obtain a uniformly heated ingot;

[0008] The homogenization treatment includes first-stage heating, first-stage heat preservation, second-stage heating, second-stage heat preservation, third-stage heating and third-stage heat preservation performed in sequence.

[0009] In some specific embodiments, the primary heating temperature is 445-515°C.

[0010] In some specific embodiments, the temperature of the first-level insulation is 425-475° C., and the time is 3-8 hours.

[0011] In some specific embodiments, the temperature of the secondary heating is 475-545°C.

[0012] In some specific embodiments, the temperature of the secondary insulation is 455-505° C., and the time is 3-8 hours.

[0013] In some specific embodiments, the temperature of the three-stage heating is 510-530°C.

[0014] In some specific embodiments, the temperature of the third-level insulation is 510-530° C., and the time is 20-28 hours.

[0015] In some specific embodiments, the temperature of the first-stage heating is 470-490° C., the temperature of the first-stage insulation is 440-460° C., and the time of the first-stage insulation is 4-6 hours.

[0016] In some specific embodiments, the temperature of the secondary heating is 500-520° C., the temperature of the secondary insulation is 470-490° C., and the time of the secondary insulation is 4-6 hours.

[0017] In some specific embodiments, the temperature of the three-stage heating is 516-520° C., the temperature of the three-stage insulation is 516-520° C., and the time of the three-stage insulation is 22-26 hours.

[0018] The present application provides a homogenization method for Al-Cu-Mg-Ag aluminum alloy ingots, which homogenizes the Al-Cu-Mg-Ag aluminum alloy ingots to obtain uniformly heated ingots; the homogenization treatment includes sequentially performing primary heating, primary insulation, secondary heating, secondary insulation, tertiary heating, and tertiary insulation. The homogenization method for Al-Cu-Mg-Ag aluminum alloy ingots provided by the present application adopts sequentially performing primary heating, primary insulation, secondary heating, secondary insulation, tertiary heating, and tertiary insulation. The above multi-stage heating and multi-stage insulation effectively reduce compound aggregation, and ultimately improve the mechanical properties of the aluminum alloy. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the installation of a heating couple during the homogenization process of the Al-Cu-Mg-Ag aluminum alloy ingot of the present invention;

[0020] Figure 2This is a SEM photograph of the Al-Cu-Mg-Ag aluminum alloy ingot after secondary heat preservation of the present invention. DETAILED DESCRIPTION

[0021] In order to further understand the present invention, preferred embodiments of the present invention are described below in conjunction with examples. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, rather than limiting the claims of the present invention.

[0022] In view of the problem of high compound ratio in Al-Cu-Mg-Ag aluminum alloy ingots for forgings in the prior art, the present application provides a method for homogenizing Al-Cu-Mg-Ag aluminum alloy ingots, which effectively controls the compound ratio and reduces the aggregation of compounds by introducing a multi-stage homogenization process of first-stage heating, first-stage insulation, second-stage heating, second-stage insulation, third-stage heating and third-stage insulation in sequence, and finally improves the mechanical properties of Al-Cu-Mg-Ag aluminum alloys. Specifically, the present invention provides a method for homogenizing Al-Cu-Mg-Ag aluminum alloy ingots, comprising the following steps:

[0023] The Al-Cu-Mg-Ag aluminum alloy ingot is homogenized to obtain a uniformly heated ingot;

[0024] The homogenization treatment includes first-stage heating, first-stage heat preservation, second-stage heating, second-stage heat preservation, third-stage heating and third-stage heat preservation performed in sequence.

[0025] In the homogenization method of the Al-Cu-Mg-Ag aluminum alloy ingot provided in the present application, the present application performs homogenization treatment on the aluminum alloy ingot, wherein the preparation method of the aluminum alloy ingot is carried out according to a method well known to those skilled in the art, and the present application has no special restrictions on this.

[0026] Prior to the homogenization heat treatment, the present application firstly carried out a preparation stage, according to Figure 1 Drill holes at indicated positions, with a hole diameter of 4.5-6.5 mm and a depth of 7.5 mm ± 1.5 mm, insert the thermocouple into the bottom of the hole, one thermocouple per hole, and seal with aluminum wire or rivets, and then tie and fix the thermocouple with iron wire. The present invention has only one ingot, so thermocouples are used at the head, middle and tail.

[0027] During the homogenization process, it includes primary heating, primary insulation, secondary heating, secondary insulation, tertiary heating, and tertiary insulation in sequence; first, the primary heating enters the heating and temperature rise stage. After entering the insulation temperature, when the temperature measurement value of one electric couple reaches the insulation temperature, it can be transferred to the insulation temperature constant temperature. When the temperature measurement values ​​of the three electric couples all reach the insulation temperature range, the insulation time will be calculated; during the insulation process, it should be ensured that the temperature measurement values ​​of the three electric couples are always within the insulation temperature range. After the insulation is completed, the secondary heating and temperature rise stage will be carried out immediately. The temperature is as described above. The insulation time will be calculated only when the temperature measurement values ​​of the three electric couples all reach the secondary insulation temperature range. After the secondary insulation is completed, the tertiary heating and temperature rise stage will be carried out immediately. When the temperature measurement values ​​of the three electric couples all reach the tertiary insulation temperature range, the insulation time will be calculated. After the tertiary insulation time is over, the heat treatment is completed and the furnace is taken out of the furnace for natural cooling.

[0028] Specifically, the primary heating temperature is 450℃~510℃, preferably 470℃~490℃, more preferably 480℃, and the temperature is controlled at ±5℃; the primary insulation temperature is 430℃~470℃, preferably 440℃~460℃, more preferably 450℃, and the primary insulation time is 3~8h, preferably 4~6h; during the primary insulation process, according to the preferred parameters, when the temperature value of one galvanic couple reaches 445℃, the insulation temperature is constant, and when the temperature values ​​of the three galvanic couples all reach the insulation temperature range of 450℃ (temperature control ±5℃), the insulation time is calculated, and the insulation time is preferably 4~6h. The primary heating and primary insulation are used to realize the diffusion of elements and the multi-phase pole formed by the dissolution.

[0029] Specifically, the temperature of the secondary heating is 480-540°C, preferably 500-520°C, more preferably 510°C, and the temperature is controlled at ±5°C; the temperature of the secondary insulation is 460-500°C, preferably 470-490°C, and most preferably 480°C (temperature controlled at ±5°C), and the time of the secondary insulation is 3-8h, preferably 4-6h; in the process of secondary insulation, according to the preferred parameters, after the first insulation is completed and the secondary heating is started, when the temperature value of one of the galvanic couples reaches 475°C, the insulation temperature is constant, and when the temperature values ​​of the three galvanic couples all reach the insulation temperature range of 480°C (temperature controlled at ±5°C), the insulation time is calculated, and the insulation time is preferably 4-6h. The secondary heating and secondary insulation are used to achieve the low melting point Al in the ingot. 2 The CuMg phase and AlCuMgAg phase are fully dissolved back. Figure 2 This is a SEM photo of the aluminum alloy ingot after secondary insulation. The following table lists the specific composition of different positions.

[0030] Table 1 Specific composition of SEM photos of aluminum alloy ingots after secondary insulation

[0031]

[0032]

[0033] Specifically, the temperature of the three-stage heating is 510-530°C, preferably 516°C-520°C, more preferably 516°C, and the temperature is controlled at ±3°C; the time is 1-10h, preferably 2-9h; the temperature of the three-stage insulation is 510-530°C, preferably 516°C-520°C, most preferably 516°C (temperature control ±3°C), and the time of the three-stage insulation is 20-28h, preferably 22-26h; in the process of three-stage insulation, according to the preferred parameters, after the second-stage insulation ends and the third-stage heating temperature rise begins, when the temperature measurement value of one galvanic couple reaches 511°C, the insulation temperature is set, and when the temperature measurement values ​​of the three galvanic couples all reach the insulation temperature range of 516°C (temperature control ±3°C), the insulation time is calculated, and the insulation time is preferably 22-26h. The three-stage heating and the three-stage insulation can effectively reduce the residual Al 2 The amount of Cu phase.

[0034] The homogenization method provided in the present application is directed to Al-Cu-Mg-Ag alloys, and more specifically, the composition range of the aluminum alloy is as follows.

[0035] Si: ≤0.08wt%;

[0036] Fe: ≤0.10wt%;

[0037] Cu: 4.80-5.40wt%;

[0038] Mn: 0.45-0.80wt%;

[0039] Mg: 0.70-1.00wt%;

[0040] Zn: ≤0.25wt%;

[0041] Ag: 0.40-0.70wt%;

[0042] Ti: ≤0.06wt%;

[0043] Zr: 0.08-0.15wt%;

[0044] Be: ≤0.0001wt%;

[0045] The balance is Al.

[0046] The present invention optimizes the homogenization system of Al-Cu-Mg-Ag alloy to obtain an ingot with less Al 2The ingot with CuMg phase compound aggregation ultimately improves the mechanical properties of Al-Cu-Mg-Ag alloy. In summary, the present application performs homogenization treatment on Al-Cu-Mg-Ag ingot to make the obtained ingot meet the use requirements.

[0047] In order to further understand the present invention, the homogenization method of the Al-Cu-Mg-Ag aluminum alloy ingot provided by the present invention is described in detail below in conjunction with the embodiments. The protection scope of the present invention is not limited by the following embodiments.

[0048] Example 1

[0049] The Al-Cu-Mg-Ag aluminum alloy ingot is homogenized to obtain a uniformly heated ingot; the homogenization treatment includes primary heating, primary insulation, secondary heating, secondary insulation, tertiary heating, and tertiary insulation; the primary heating temperature is set at 480°C; the primary insulation temperature is set at 450°C for 5h; the secondary ingot heating temperature is set at 510°C, the secondary ingot insulation temperature is set at 480°C, and the time is 5h; the tertiary ingot heating temperature is set at 516°C, the tertiary ingot insulation temperature is set at 516°C, and the time is 24h to obtain a uniformly heated aluminum alloy ingot.

[0050] Comparative Example 1

[0051] The Al-Cu-Mg-Ag aluminum alloy ingot is homogenized to obtain a uniformly heated ingot; the homogenization treatment includes primary heating, primary insulation, secondary heating, secondary insulation, tertiary heating, and tertiary insulation; the primary heating is set at 480°C; the primary insulation is set at 450°C for 5h; the secondary ingot heating is set at 510°C, the secondary ingot insulation is set at 480°C, and the time is 5h; the tertiary ingot heating is set at 500°C, the tertiary ingot insulation is set at 500°C, and the time is 24h.

[0052] Comparative Example 2

[0053] The Al-Cu-Mg-Ag aluminum alloy ingot is homogenized to obtain a uniformly heated ingot; the homogenization treatment includes primary heating, primary insulation, secondary heating, secondary insulation, tertiary heating, and tertiary insulation; the primary heating is set at 480°C; the primary insulation is set at 450°C for 5h; the secondary ingot heating is set at 510°C, the secondary ingot insulation is set at 480°C, and the time is 5h; the tertiary ingot heating is set at 540°C, the tertiary ingot insulation is set at 540°C, and the time is 24h to obtain a heated aluminum alloy ingot.

[0054] The composition of the Al-Cu-Mg-Ag aluminum alloy ingot in the above embodiments and comparative examples is specifically as follows:

[0055] Table 2 Composition data of aluminum alloy ingots of embodiments and comparative examples

[0056]

[0057]

[0058] Index detection

[0059] Compound percentage detection and mechanical property detection were performed on the ingots of a certain specification prepared by the homogenization system plus cooling process in the embodiment of the present invention and the comparative example; wherein, the compound percentage detection method is GB / T 3246.1 "Deformed aluminum and aluminum alloy product structure inspection method", and the test results are shown in Table 3, and the mechanical property detection method is ASTM B557 "Standard test method for tensile test of deformed and cast aluminum and magnesium alloy products", and the test results are shown in Table 4;

[0060] Table 3 Compound size ratio data of aluminum alloy ingots after homogenization treatment in the embodiments and comparative examples

[0061]

[0062] Table 4 Mechanical properties of the final aluminum alloy ingots after homogenization treatment in the embodiments and comparative examples

[0063]

[0064] This application studies a high-strength and heat-resistant Al-Cu-Mg-Ag homogenization method. Since the alloy compounds of this series are difficult to control and the performance is relatively unstable, the present invention prepares an Al-Cu-Mg-Ag aluminum alloy ingot suitable for uses such as wheels, which has a small compound ratio and meets the mechanical properties requirements.

[0065] The above embodiments are only used to help understand the method and core idea of ​​the present invention. It should be noted that, for those skilled in the art, several improvements and modifications can be made to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

[0066] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for homogenizing an Al-Cu-Mg-Ag aluminum alloy ingot, comprising the following steps: The Al-Cu-Mg-Ag aluminum alloy ingot is homogenized to obtain a uniformly heated ingot; The homogenization treatment includes first-stage heating, first-stage heat preservation, second-stage heating, second-stage heat preservation, third-stage heating and third-stage heat preservation performed in sequence.

2. The homogenization method according to claim 1, characterized in that: The temperature of the primary heating is 445-515°C.

3. The homogenization method according to claim 1, characterized in that: The temperature of the first-level insulation is 425-475° C., and the time is 3-8 hours.

4. The homogenization method according to claim 1, characterized in that: The temperature of the secondary heating is 475-545°C.

5. The homogenization method according to claim 1, characterized in that: The temperature of the secondary insulation is 455-505° C. and the time is 3-8 hours.

6. The homogenization method according to claim 1, characterized in that: The temperature of the three-stage heating is 510-530°C.

7. The homogenization method according to claim 1, characterized in that: The temperature of the third-level insulation is 510-530° C., and the time is 20-28 hours.

8. The homogenization method according to claim 1, characterized in that: The temperature of the first-stage heating is 470-490° C., the temperature of the first-stage insulation is 440-460° C., and the time of the first-stage insulation is 4-6 hours.

9. The homogenization method according to claim 1, characterized in that: The temperature of the secondary heating is 500-520° C., the temperature of the secondary insulation is 470-490° C., and the time of the secondary insulation is 4-6 hours.

10. The homogenization method according to claim 1, characterized in that: The temperature of the three-stage heating is 516-520° C., the temperature of the three-stage insulation is 516-520° C., and the time of the three-stage insulation is 22-26 hours.

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