Disclosure of Invention
The purpose of the invention is: aiming at the practical application of the weight reduction requirement of the existing weapon, an 800 MPa-grade aluminum alloy section and a preparation method thereof are provided.
In order to solve the technical problem, the technical scheme of the invention is as follows:
in a first aspect, an 800MPa grade aluminum alloy extruded profile is provided, wherein the alloy comprises the following chemical components in percentage by weight: 9.0-12.5% of Zn, 2.5-3.5% of Mg, 0.8-1.5% of Cu, less than or equal to 0.10% of Fe, less than or equal to 0.10% of Si, less than or equal to 0.05% of other impurities, less than or equal to 0.15% of total amount, and the balance of Al.
1-2 of Zr and Sc are added in the chemical components of the alloy, and the weight percentage is as follows: zr0.08-0.15% and Sc 0.05-0.25%.
On the other hand, the preparation method of the 800 MPa-grade aluminum alloy extruded section comprises the following steps:
step one, preparing materials according to the chemical components and weight percentage of alloy, casting to obtain a semi-continuous ingot, wherein the size of the ingot is
Step two, carrying out three-stage homogenization treatment on the semicontinuous ingot casting, which comprises the following specific steps:
the first-stage homogenization temperature is 390-410 ℃, and the heat preservation time is 20-24 h; the second-stage homogenization temperature is 460-470 ℃; the heat preservation time is 15-24 h; the third-stage homogenization temperature is 470-478 ℃, the heat preservation time is 15-24 h, and the total heat preservation time is more than 50 h;
step three, performing hot extrusion after the homogenized cast ingot is peeled, wherein the extrusion ratio is controlled to be 20 or more, and the thickness of the final extruded section is not less than 40mm, and the width is not less than 150 mm;
and step four, carrying out solid solution and aging heat treatment on the section.
Preferably, the second step is started within 3h after the fusion casting in the first step is finished. And the cast ingot is prevented from cracking in the placing process.
The casting process in the first step is as follows:
(1) melting in a melting furnace, wherein the melting temperature is 700-780 ℃;
(2) refining the completely melted metal, wherein the temperature of the metal is maintained within the range of 690-730 ℃ during refining;
(3) fully standing for at least 30min after refining;
(4) and (3) starting casting after fully standing, wherein the casting temperature is 690-700 ℃, the casting speed is 15-22 mm/min, and the casting pressure is 0.03-0.08 MPa.
And step two, after homogenization is finished, cooling along with the furnace to below 150 ℃, discharging and air cooling.
Preferably, the parameters in the process of the step three hot extrusion technology are as follows: the blank temperature is 350-375 ℃, and the extrusion speed is 1-4 m/min.
Preferably, the solid solution in the fourth step adopts two-stage solid solution, the first-stage solid solution temperature is 455-460 ℃, and the second-stage solid solution temperature is: 465 to 477 ℃.
Preferably, the aging in the fourth step adopts peak aging, and the process comprises the following steps: keeping the temperature at 90-125 ℃ for 10-72 h.
The invention has the beneficial effects that:
the sectional material prepared by the method has the size thickness not less than 40mm and the width not less than 150mm, the L-direction tensile strength of the material can reach more than 800MPa, the yield strength reaches 750MPa, and the elongation is higher than 8 percent; the LT tensile strength can reach 750MPa, the yield strength can reach 700MPa, and the elongation is higher than 6%. The aluminum alloy weight reduction efficiency of the section bar can reach more than 20% by replacing 600MPa grade 7150 and 7055 aluminum alloy, and the section bar has wide application prospect.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the following description will clearly and completely describe the embodiments. It is to be understood that the embodiments described are only a few embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Features of various aspects of embodiments of the invention will be described in detail below. In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. It will be apparent, however, to one skilled in the art that the present invention may be practiced without these specific details. The following description of the embodiments is merely intended to better understand the present invention by illustrating examples thereof. The present invention is not limited to any particular arrangement or method provided below, but rather covers all product structures, any modifications, alterations, etc. of the method covered without departing from the spirit of the invention.
In the following description, well-known structures and techniques are not shown to avoid unnecessarily obscuring the present invention.
Example 1:
the preparation process of the alloy comprises the following steps:
(1) the alloy proportion is Zn: 9.0%, Mg: 2.5%, Cu: 0.8 percent; preparing 99.99 percent of refined Al ingot, pure Zn ingot, pure Mg ingot and Al-Cu intermediate alloy according to the weight percentage;
(2) melting in a melting furnace, wherein the melting temperature is 700-780 ℃;
(3) adding a refining agent into the completely melted metal, continuously stirring for refining, wherein the refining is carried out in batches, and the metal temperature is maintained within the range of 690-750 ℃ during refining;
(4) after refining, standing in vacuum, vacuumizing to 1000-1200 Pa, and standing for 30-35 min;
(5) the casting is started after the aluminum base is fully stood, the thickness of the pure aluminum base is not less than 100mm, the casting temperature is 690-700 ℃, the casting speed is 15-22 mm/min, and the casting pressure is controlled at 0.03-0.08 MPa;
(6) casting to obtain semi-continuous cast ingot with the size of the cast ingot
(7) Homogenizing the cast ingot within 3 hours after the casting is finished;
(8) the ingot casting adopts a three-level homogenization process,
the ingot casting homogenization process comprises the following steps: the first-stage homogenization temperature is 390 ℃, and the heat preservation time is 20 h; the second-stage homogenization temperature is 460 ℃; the heat preservation time is 15 h; the third-stage homogenization temperature is 470 ℃, and the heat preservation time is 15 hours;
(9) after homogenization, cooling along with the furnace to below 150 ℃, discharging and air cooling;
(10) peeling the homogenized cast ingot, and casting the ingot with the diameter after peeling
(11) Selecting a mould to carry out hot extrusion on the cast ingot, wherein the extrusion ratio is 20, and the size of the mould is 40 multiplied by 150 mm;
(12) in the extrusion process, the initial heating temperature of the cast ingot is 360 ℃, the temperature of the cast ingot in the extrusion process is controlled to be 350-375 ℃, and the extrusion speed is controlled to be 1-4 m/min;
(13) the extruded section is subjected to two-stage solid solution, and the solid solution system is as follows: the first-stage solid solution temperature is 455 ℃, the heat preservation time is 2 hours, and the second-stage solid solution temperature is as follows: keeping the temperature at 470 ℃ for 4 h;
(14) the extruded section is subjected to peak aging heat treatment, and the heat preservation temperature is as follows: keeping the temperature at 90 ℃ for 72h, and cooling with air in the furnace.
The room temperature tensile properties of the profile obtained in example 1 are shown in Table 1 below, where σ isbFor tensile strength, σ0.2For yield strength, δ is elongation.
TABLE 1
Example 2:
(1) the alloy proportion is Zn: 10.5%, Mg: 3.0%, Cu: 1.1%, Zr: 0.11 percent; preparing 99.99 percent of refined Al ingot, pure Zn ingot, pure Mg ingot, Al-Cu intermediate alloy and Al-Zr intermediate alloy according to the weight percentage;
(2) melting in a melting furnace, wherein the melting temperature is 700-780 ℃;
(3) adding a refining agent into the completely melted metal, continuously stirring for refining, wherein the refining is carried out in batches, and the metal temperature is maintained within the range of 690-750 ℃ during refining;
(4) after refining, standing in vacuum, vacuumizing to 1000-1200 Pa, and standing for 30-35 min;
(5) the casting is started after the aluminum base is fully stood, the thickness of the pure aluminum base is not less than 100mm, the casting temperature is 690-700 ℃, the casting speed is 15-22 mm/min, and the casting pressure is controlled at 0.03-0.08 MPa;
(6) casting to obtain semi-continuous cast ingot with the size of the cast ingot
(7) Homogenizing the cast ingot within 3 hours after the casting is finished;
(8) the ingot casting adopts a three-level homogenization process,
the ingot casting homogenization process comprises the following steps: the first-stage homogenization temperature is 400 ℃, and the heat preservation time is 22 h; the second-stage homogenization temperature is 465 ℃; the heat preservation time is 20 h; the third-stage homogenization temperature is 474 ℃ and the heat preservation time is 20 hours;
(9) after homogenization, cooling along with the furnace to below 150 ℃, discharging and air cooling;
(10) peeling the homogenized cast ingot, and casting the ingot with the diameter after peeling
(11) Selecting a mould to carry out hot extrusion on the cast ingot, wherein the extrusion ratio is 25, and the size of the mould is 45 multiplied by 175 mm;
(12) in the extrusion process, the initial heating temperature of the cast ingot is 360 ℃, the temperature of the cast ingot in the extrusion process is controlled to be 350-375 ℃, and the extrusion speed is controlled to be 1-4 m/min;
(13) the extruded section is subjected to two-stage solid solution, and the solid solution system is as follows: the first-stage solid solution temperature is 458 ℃, the heat preservation time is 2 hours, and the second-stage solid solution temperature is as follows: 471 ℃, and the heat preservation time is 4 hours;
(14) the extruded section is subjected to peak aging heat treatment, and the heat preservation temperature is as follows: keeping the temperature at 110 ℃ for 32h, and cooling with air in the furnace.
The room temperature tensile properties of the profile obtained in example 2 are shown in Table 2 below, where σ isbFor tensile strength, σ0.2The yield strength, delta the elongation,
TABLE 2
Example 3:
(1) the alloy proportion is Zn: 11.0%, Mg: 3.0%, Cu: 1.1%, Sc: 0.15 percent; preparing 99.99 percent of refined Al ingot, pure Zn ingot, pure Mg ingot, Al-Cu intermediate alloy and Al-Zr intermediate alloy according to the weight percentage;
(2) melting in a melting furnace, wherein the melting temperature is 700-780 ℃;
(3) adding a refining agent into the completely melted metal, continuously stirring for refining, wherein the refining is carried out in batches, and the metal temperature is maintained within the range of 690-750 ℃ during refining;
(4) after refining, standing in vacuum, vacuumizing to 1000-1200 Pa, and standing for 30-35 min;
(5) the casting is started after the aluminum base is fully stood, the thickness of the pure aluminum base is not less than 100mm, the casting temperature is 690-700 ℃, the casting speed is 15-22 mm/min, and the casting pressure is controlled at 0.03-0.08 MPa;
(6) casting to obtain semi-continuous cast ingot with the size of the cast ingot
(7) Homogenizing the cast ingot within 3 hours after the casting is finished;
(8) the ingot casting adopts a three-level homogenization process,
the ingot casting homogenization process comprises the following steps: the first-stage homogenization temperature is 400 ℃, and the heat preservation time is 22 h; the second-stage homogenization temperature is 465 ℃; the heat preservation time is 20 h; the third-stage homogenization temperature is 474 ℃ and the heat preservation time is 20 hours;
(9) after homogenization, cooling along with the furnace to below 150 ℃, discharging and air cooling;
(10) peeling the homogenized cast ingot, and casting the ingot with the diameter after peeling
(11) Selecting a mould to carry out hot extrusion on the cast ingot, wherein the extrusion ratio is 20, and the size of the mould is 40 multiplied by 150 mm;
(12) in the extrusion process, the initial heating temperature of the cast ingot is 360 ℃, the temperature of the cast ingot in the extrusion process is controlled to be 350-375 ℃, and the extrusion speed is controlled to be 1-4 m/min;
(13) the extruded section is subjected to two-stage solid solution, and the solid solution system is as follows: the first-stage solid solution temperature is 458 ℃, the heat preservation time is 2 hours, and the second-stage solid solution temperature is as follows: 471 ℃, and the heat preservation time is 4 hours;
(14) the extruded section is subjected to peak aging heat treatment, and the heat preservation temperature is as follows: keeping the temperature at 110 ℃ for 32h, and cooling with air in the furnace.
The room temperature tensile properties of the profile obtained in example 3 are shown in Table 3 below, where σ isbFor tensile strength, σ0.2The yield strength, delta the elongation,
TABLE 3
Example 4:
(1) the alloy proportion is Zn: 12.5%, Mg: 3.5%, Cu: 1.5%, Zr: 0.15 percent and Sc 0.25 percent; preparing 99.99 percent of refined Al ingot, pure Zn ingot, pure Mg ingot, Al-Cu intermediate alloy, Al-Zr intermediate alloy and Al-Sc intermediate alloy according to the weight percentage;
(2) melting in a melting furnace, wherein the melting temperature is 700-780 ℃;
(3) adding a refining agent into the completely melted metal, continuously stirring for refining, wherein the refining is carried out in batches, and the metal temperature is maintained within the range of 690-750 ℃ during refining;
(4) after refining, standing in vacuum, vacuumizing to 1000-1200 Pa, and standing for 30-35 min;
(5) the casting is started after the aluminum base is fully stood, the thickness of the pure aluminum base is not less than 100mm, the casting temperature is 690-700 ℃, the casting speed is 15-22 mm/min, and the casting pressure is controlled at 0.03-0.08 MPa;
(6) casting to obtain semi-continuous cast ingot with the size of the cast ingot
(7) Homogenizing the cast ingot within 3 hours after the casting is finished;
(8) the ingot casting adopts a three-level homogenization process,
the ingot casting homogenization process comprises the following steps: the first-stage homogenization temperature is 410 ℃, and the heat preservation time is 24 hours; the second-stage homogenization temperature is 470 ℃; the heat preservation time is 24 h; the third-stage homogenization temperature is 478 ℃, and the heat preservation time is 24 hours;
(9) after homogenization, cooling along with the furnace to below 150 ℃, discharging and air cooling;
(10) peeling the homogenized cast ingot, and casting the ingot with the diameter after peeling
(11) Selecting a mould to carry out hot extrusion on the cast ingot, wherein the extrusion ratio is 30, and the size of the mould is 40 multiplied by 150 mm;
(12) in the extrusion process, the initial heating temperature of the cast ingot is 360 ℃, the temperature of the cast ingot in the extrusion process is controlled to be 350-375 ℃, and the extrusion speed is controlled to be 1-4 m/min;
(13) the extruded section is subjected to two-stage solid solution, and the solid solution system is as follows: the first-stage solid solution temperature is 460 ℃, the heat preservation time is 2h, and the second-stage solid solution temperature is: 477 ℃, and keeping the temperature for 4 hours;
(14) the extruded section is subjected to peak aging heat treatment, and the heat preservation temperature is as follows: keeping the temperature at 125 ℃ for 10h, and cooling with air in the furnace.
The room temperature tensile properties of the profile obtained in example 4 are shown in Table 4 below, where σ isbFor tensile strength, σ0.2The yield strength, delta the elongation,
TABLE 4 tensile Properties at room temperature of the profiles
From the performance analysis, the large-size 800 MPa-grade aluminum alloy section provided by the invention has stable performance, the L-directional ultimate tensile strength is stable and reaches more than 800MPa, the elongation is higher than 8%, the LT-directional performance tensile strength is stable and reaches more than 750MPa, the elongation is higher than 6%, the anisotropy difference is small, and the large-size 800 MPa-grade aluminum alloy section has a wide application prospect in the fields of aviation, aerospace, nuclear industry, transportation, weaponry and the like.
Finally, it should be noted that: the above embodiments are only for illustrating the technical solutions of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily conceive various equivalent modifications or substitutions within the technical scope of the present invention, and these modifications or substitutions should be covered within the scope of the present invention.