CN110157962B - Al-Zn-Mg-Cu series ultrahigh-strength aluminum alloy and preparation method thereof - Google Patents
Al-Zn-Mg-Cu series ultrahigh-strength aluminum alloy and preparation method thereof Download PDFInfo
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Abstract
The invention relates to a component regulation, processing and heat treatment process of an ultrahigh-strength and ultrahigh-toughness aluminum alloy material for aerospace, and particularly provides an Al-Zn-Mg-Cu series ultrahigh-strength aluminum alloy and a preparation method thereof aiming at the requirements of high-strength, high-toughness and high-hardenability aluminum alloys required by aerospace, belonging to the technical field of aluminum alloys. The aluminum alloy comprises the following components in percentage by mass: 7.2-9.5% of Zn, 1.2-2.5% of Mg, 1.3-1.9% of Cu, 0.08-0.15% of Zr, 0.05% of Ti, 0.05% of Mn, 0.04% of Cr, 0.05% of Fe, 0.05% of Si, 0.15% of total impurities and the balance of Al. Compared with the existing aluminum alloy, the technical scheme of the invention does not need to improve the cost, and can realize the comprehensive properties of strength, toughness and high hardenability; the preparation and heat treatment process of the invention has no waste water and waste gas emission, no pollution and lower requirement on equipment, and is beneficial to industrial production, popularization and application.
Description
Technical Field
The invention relates to a component regulation, processing and heat treatment process of an ultrahigh-strength and ultrahigh-toughness aluminum alloy material for aerospace, and particularly provides an Al-Zn-Mg-Cu series ultrahigh-strength aluminum alloy and a preparation method thereof aiming at the requirements of high-strength, high-toughness and high-hardenability aluminum alloys required by aerospace, belonging to the technical field of aluminum alloys.
Background
The Al-Zn-Mg-Cu aluminum alloy has the characteristics of high specific strength, high specific modulus, good electric and heat conduction corrosion resistance, excellent cutting performance and the like, and is widely applied to aerospace, automobiles, mechanical manufacturing, ships, chemical industry and civil industry. With the wide development of the world aerospace industry, the requirement on high-strength aluminum alloy is higher and higher. However, the improvement of the strength generally causes the reduction of the plasticity of the alloy, and the contradiction between the strength and the toughness must be solved to obtain the alloy with high strength and high plasticity, so that the comprehensive performance is improved. Meanwhile, in order to meet the requirements of large aerospace materials, the aluminum alloy has high strength and toughness and good hardenability, namely the strengthening phase cannot be excessively sensitive to the temperature gradient in the precipitation process.
The optimization and improvement of the performance of the aluminum alloy are mainly realized by five ways: firstly, the main alloy element is regulated and controlled to realize the control of the category of a strengthening phase, thereby regulating the macroscopic property of the alloy; adding microalloy elements, and refining and strengthening the aluminum alloy matrix through preferential precipitation of microalloy phases; thirdly, in a forming mode, the improvement of specific performance is obtained through in-situ precipitation, composite implantation or quick cooling forming; fourthly, processing and forming, namely refining crystal grains by utilizing deformation and forming dislocation pinning to improve the alloy performance; and fifthly, a heat treatment process is adopted, and the size and distribution of a strengthening phase are improved through diffusion, redissolution and precipitation of a precipitated phase, so that the microstructure is optimized, and the alloy performance is improved.
At present, the regulation and control of aluminum alloy components reported at home and abroad mostly adopt the addition of rare earth elements to form a dispersed phase to pin dislocation, a subboundary and a crystal boundary, play roles in dispersion strengthening and substructure strengthening and realize the improvement of performance. However, rare earths are expensive and are not suitable for use in large quantities in structural materials. And the heat treatment process, including homogenization, solid solution and aging, is completed by single-stage or double-stage strengthening homogenization and solid solution and combining peak aging, so that the win-win of strength and toughness is difficult to realize.
The literature research shows that the specific process of the main alloy element regulation and the cryogenic heat treatment of the Al-Zn-Mg-Cu aluminum alloy is not reported in a public way.
Disclosure of Invention
The invention provides an Al-Zn-Mg-Cu series ultrahigh-strength aluminum alloy and a preparation method thereof aiming at a large aluminum alloy required by aerospace, wherein the aluminum alloy optimizes the strengthening phase type of the aluminum alloy by adjusting main alloy elements, so that the strength and toughness of the alloy are ensured, and meanwhile, the aluminum alloy has high hardenability; and by developing a double-deep-cooling embedded multi-stage heat treatment process on the basis of the traditional heat treatment process, the distribution state of the strengthening phase is adjusted, the metastable state dispersion distribution density of the matrix is improved, and the intermittent distribution and no precipitation zone of the grain boundary stable phase are regulated and controlled, so that the improvement of the comprehensive performance of the ultrahigh-strength ultrahigh-toughness aluminum alloy is realized.
The technical scheme adopted by the invention is as follows:
an Al-Zn-Mg-Cu series ultrahigh-strength aluminum alloy comprises the following components in percentage by mass: 7.2-9.5% of Zn, 1.2-2.5% of Mg, 1.3-1.9% of Cu, 0.08-0.15% of Zr, 0.05% of Ti, 0.05% of Mn, 0.04% of Cr, 0.05% of Fe, 0.05% of Si, 0.15% of total impurities and the balance of Al.
The invention limits the content of Cu element within 1.3-1.9% and limits S phase (Al)2The maximum volume fraction of CuMg) phase precipitation, the volume fraction of a strengthening phase in the alloy is regulated and controlled by setting the content of Mg element within the range of 1.2-2.5% to meet the requirements of strength and toughness, and the content of Zn element is regulated and controlled within the range of 7.2-9.5% to improve η phase (MgZn)2) And Mg element is consumed in the precipitation process, and S phase (Al) is inhibited2CuMg) is formed.
The invention also provides a preparation method of the more than one aluminum alloy, which comprises the following steps:
(1) according to the alloy components, the ingot is formed by batching, smelting (alloying), melt purification and grain refinement treatment, casting and forming, and demoulding and air cooling. The smelting temperature is controlled at 750-770 ℃, and if the temperature is too high, the burning loss of the alloy is too large. Melt purification by N2Refining to make it reach low hydrogen content and avoid hydrogen induced cracking. The whole process flow needs to be 'three pure': firstly, the content of impurities such as Fe, Si and the like is low; secondly, oxide Al2O3Low iso-oxidation inclusions; and thirdly, the hydrogen-containing inclusions are low. The production of (Fe, Cr) SiAl which can seriously affect the fracture toughness of the alloy is avoided as much as possible12、(Fe,Mn,Cu)Al6、Cu2FeAl7、Mg2Coarse impurity phases such as Si.
(2) Carrying out composite homogenization treatment on the cast ingot obtained in the step (1): keeping the temperature at 430 ℃ for 46 hours, then heating to 467 ℃ and keeping the temperature for 4 hours, and then discharging from the furnace and air cooling.
(3) And (3) carrying out hot extrusion on the cast ingot subjected to the composite homogenization treatment in the step (2). During extrusion, the metal temperature is 400-440 ℃, and the heating time is 2 h; the temperature of the extrusion cylinder, the die and the cushion is 440-480 ℃, and the heating time is 12 h.
(4) And (3) carrying out cryogenic treatment on the extruded part obtained in the step (3): the temperature was maintained at-197 ℃ for 36 hours.
(5) Carrying out three-stage solid solution on the subzero treatment sample obtained in the step (4): keeping the temperature of 450-470 ℃ for 20-40 minutes, heating to 470-480 ℃, keeping the temperature for 20 minutes, heating to 480-490 ℃, keeping the temperature for 20 minutes, and then performing water quenching or oil quenching.
(6) And (3) carrying out double-stage aging on the solid solution sample obtained in the step (5): keeping the temperature at 120-135 ℃ for 16 hours, then heating to 190 ℃ and keeping the temperature for 10 minutes.
(7) And (4) carrying out cryogenic treatment on the aging sample obtained in the step (6) again: the temperature was maintained at-197 ℃ for 36 hours.
The invention is based on the following principle:
theoretical and experimental researches show that the main strengthening phase of the Al-Zn-Mg-Cu aluminum alloy is η phase (MgZn)2) While easily forming S phase (Al)2CuMg) and theta phase (Al)2Cu). Wherein, S phase (Al)2CuMg) and η phases (MgZn)2) η phase (MgZn) with similar precipitation temperature2) Compared with S phase (Al)2CuMg) and theta phase (Al)2Cu) has a greater enthalpy of formation, from a thermodynamic point of view η phase (MgZn)2) The driving force for precipitation is greater, so during casting, η phase (MgZn)2) With S phase (Al)2CuMg) competitive precipitation, meanwhile, η phase (MgZn)2) Compared with S phase (Al)2CuMg) and theta phase (Al)2Cu) has a smaller binding energy and thus is easily decomposed and diffused, and thermodynamic studies have shown that η phase (MgZn)2) Is precipitated without S phase (Al)2CuMg) and theta phase (Al)2Cu) depends on the change of temperature gradient, so that the sensitivity to temperature is not strong in the heat treatment process, especially the quenching process, and the high hardenability of the bulk material can be realized2) Sufficiently precipitate, and control the S phase (Al)2CuMg) volume fraction. Namely, the Cu content is properly reduced to control the brittle insoluble S phase (Al)2CuMg) and theta phase (Al)2Cu) precipitationAnd on the basis of the Mg content, the Zn content is increased, and η phase (MgZn) is ensured2) And Mg element is consumed in the precipitation process, and S phase (Al) is inhibited2CuMg) is formed.
The alloy composition design determines that the content of Cu element is within 1.3-1.9% according to the requirements of corrosion resistance and strength performance, and limits S phase (Al)2CuMg) phase precipitation. Based on Al2Atomic ratio A in CuMg phaseMg:ACu1:1, mass ratio M of two elements in the phaseMg:MCu1:2.7, if Cu is Al2The CuMg phase precipitates, and the required Mg content in the phase is in the range of 0.5-0.7%. Based on MgZn2Atomic ratio A in phaseMg:AZnMass ratio M of two elements in the phase based on 1:2Mg:MZn1: 5.4. If 0.5-0.7% of Mg is Al during casting2CuMg phase is separated out, and MgZn is formed by considering 0.1% of Mg element burning loss2The Mg content in the phase is still 0.6-1.7% to form MgZn2The content of Zn element needed by the phase is within 3.2-9.0%, and the content of Zn element is controlled within 7.2-9.5% in the invention, so as to improve η phase (MgZn)2) And Mg element is consumed in the precipitation process, and S phase (Al) is inhibited2CuMg) is formed.
In addition, a double-deep-cooling embedded multi-stage heat treatment process is developed on the basis of the traditional heat treatment process, the distribution state of a strengthening phase is adjusted, the metastable state dispersion distribution density of a matrix is improved when the strengthening phase is precipitated again after solid solution, and grain boundaries are discontinuously distributed in a stable phase, so that the comprehensive performance of the ultrahigh-strength ultrahigh-toughness aluminum alloy is improved2) Re-dissolving, raising the solid solution temperature, avoiding over-burning and realizing S phase (Al) as far as possible2CuMg) and theta phase (Al)2Cu), and finally carrying out third-stage solid solution, increasing the temperature to obtain a high supersaturated solid solution and providing a good matrix for aging precipitation, and carrying out two-stage aging, wherein the diffusion precipitation of GP zone and η' phase is realized at low temperature for long time and high temperature for short time and at low temperature for long time, and the transition to η phase (MgZn) is avoided2) The transformation of (2) is carried out by high-temperature short-time aging treatment on the basis of the time close to the peak aging time so as to realize the precipitation phase at the grain boundary of η phase (MgZn)2) The fourth step, subzero treatment is carried out again after aging, because the matrix belongs to supersaturated solid under the subzero condition, the secondary precipitation of solute can be realized, thermodynamic research shows that under the subzero condition, the free energy difference of η' phase and η phase is very small, the driving force of phase transformation is very small, and the transformation is not easy to occur, so the transformation of strengthening opposite stable phases is avoided while the strengthening dispersion precipitation density is improved, and the strength and toughness of the alloy are improved.
Compared with the prior art, the technical scheme of the invention has the advantages that:
1. the invention provides a method for optimizing the type of a strengthening phase of an aluminum alloy by adjusting main alloy elements, so that the strength and toughness of the alloy are ensured, and the hardenability is high. Namely, the content of Mg is taken as the reference, the content of Zn is improved, and MgZn is realized2The S phase (Al) which is hard to be dissolved in the casting process and controls the brittleness by properly reducing Cu through primary precipitation in the casting process2CuMg) and theta phase (Al)2Cu)。
2. The deep cooling is carried out after the deformation, and the aim is to realize recovery by utilizing deformation residual stress and shrinkage stress, reduce matrix energy while refining grains, reduce the driving force of nucleation and growth in the solid solution process and achieve the effect of refining the grains.
3. Three-stage solid solution, combining long-term low temperature with short-term high temperature, firstly making η phase (MgZn) easy to decompose and diffuse2) Re-dissolving, raising the solid solution temperature, avoiding over-burning and realizing S phase (Al) as far as possible2CuMg) and theta phase (Al)2Cu), and finally carrying out third-stage solid solution, and increasing the temperature to obtain a high supersaturated solid solution, thereby providing a good matrix for aging precipitation.
4. Thermodynamic research shows that the free energy difference between η' phase and η phase is very small under the condition of deep cooling, the driving force of phase transformation is very small, and transformation is not easy to occur, so that the transformation of strengthening opposite stable phases is avoided while the dispersion precipitation density of the strengthening phases is improved, and the strength and the toughness of the alloy are improved.
5. Compared with the existing aluminum alloy, the technical scheme of the invention does not need to improve the cost, and can realize the comprehensive properties of strength, toughness and high hardenability.
6. The preparation and heat treatment process of the invention has no waste water and waste gas emission, no pollution and lower requirement on equipment, and is beneficial to industrial production, popularization and application.
Drawings
FIG. 1 is a process flow diagram of an Al-Zn-Mg-Cu system ultrahigh strength aluminum alloy according to the present invention;
FIG. 2 is a high resolution transmission electron microscopy HRTEM image of an Al-Zn-Mg-Cu series ultrahigh strength aluminum alloy sample (sample 4) prepared by the content ratio and process of the invention;
FIG. 3 is a SAED chart of selected area diffraction spots of an Al-Zn-Mg-Cu series ultrahigh strength aluminum alloy sample (sample 4) prepared according to the content ratio and process of the present invention;
FIG. 4 shows a tensile fracture of an Al-Zn-Mg-Cu series ultrahigh strength aluminum alloy sample (sample 4) prepared according to the content ratio and process of the present invention;
FIG. 5 is a TEM image of a sample (sample 15) of Al-Zn-Mg-Cu system ultra-high strength aluminum alloy prepared by the inventive content ratio and process;
FIG. 6 is a BSK (back-scattering electron microscope) image after three-level solid solution of an Al-Zn-Mg-Cu series ultrahigh-strength aluminum alloy sample (sample 15) prepared according to the content ratio and the process of the invention;
FIG. 7 is a scanning electron microscope picture of an Al-Zn-Mg-Cu series ultrahigh strength aluminum alloy sample (sample 15) prepared according to the content ratio and process of the present invention after an extrusion cryogenic treatment, showing that cryogenic treatment is favorable for recovery, residual stress is eliminated and grains are refined;
FIG. 8 is a BSK image and an EDS of an energy spectrum of an Al-Zn-Mg-Cu series ultrahigh strength aluminum alloy sample (sample 18) prepared by the content ratio and process of the invention;
FIG. 9 is TEM image of transmission electron microscope after aging and deep cooling of Al-Zn-Mg-Cu series ultrahigh strength aluminum alloy sample (sample 20) prepared by the inventive content ratio and process;
FIG. 10 shows BSK (Back Scattering Electron microscope) and EDS (energy Spectroscopy) of Al-Zn-Mg-Cu series ultrahigh-strength aluminum alloy sample (sample 23) which is not prepared according to the content ratio of the invention.
Detailed Description
The invention is further described with reference to the accompanying drawings and the detailed description.
Example 1: the performance comparison of Al-Zn-Mg-Cu series ultrahigh strength aluminum alloy samples according to the content ratio of the invention under different heat treatment processes
Preparing the following components in percentage by mass according to the elements in the Al-Zn-Mg-Cu series ultrahigh-strength aluminum alloy: 8.5 percent of Zn, 2.0 percent of Mg2, 1.5 percent of Cu, 0.12 percent of Zr, 0.05 percent of Ti, 0.05 percent of Mn, 0.04 percent of Cr, and Fe<0.05％,Si<0.05%, total amount of impurities<0.15 percent and the balance of Al. Smelting (alloying), melt purification and grain refinement treatment, casting and forming to form a cast ingot, demoulding and air cooling. Melt purification by N2And (5) refining. The melting temperature is controlled at 750-770 ℃, and the measured liquid phase temperature is taken as the standard. The ingot casting adopts composite homogenization treatment: keeping the temperature at 430 ℃ for 46 hours, then heating to 467 ℃ and keeping the temperature for 4 hours, discharging from the furnace and air cooling. Hot extrusion is carried out at 420 ℃, and the temperature of an extrusion cylinder, a die and a cushion is 440 ℃. And then, treating under a heat treatment process, comparing two-stage solid solution with three-stage solid solution, single-stage aging with two-stage aging, and two-stage deep cooling with three-stage deep cooling, wherein the specific process is shown in table 1, and the performance test result is shown in table 2. It can be seen from the performance test results that sample 4, i.e., the heat treatment process according to the present invention, can optimize the overall performance of the Al-Zn-Mg-Cu series ultrahigh strength aluminum alloy. FIG. 1 is a high resolution transmission electron microscopy HRTEM image of a sample 4, and the result shows the dispersion distribution of the metastable phase of the material matrix, FIG. 2 is a corresponding selected area diffraction spot SAED image showing the type of the dispersed phase, and FIG. 3 is a tensile fracture of the corresponding sample, which shows the ductile fracture of the alloy.
TABLE 1 samples of Al-Zn0.085-Mg0.02-Cu0.015 alloy obtained by different heat treatment processes (sample 4 obtained by the treatment process according to the invention)
TABLE 2 comparison of the Properties of Al-Zn0.085-Mg0.02-Cu0.015 alloy samples
Example 2: the performance comparison of Al-Zn-Mg-Cu series ultrahigh strength aluminum alloy samples according to the content ratio of the invention under different heat treatment processes
The preparation method comprises the following steps of according to the mass percent of each element in the Al-Zn-Mg-Cu series ultrahigh-strength aluminum alloy: 9.5 percent of Zn, 2.5 percent of Mg2, 1.9 percent of Cu, 0.15 percent of Zr, 0.05 percent of Ti, 0.05 percent of Mn, 0.04 percent of Cr, less than 0.05 percent of Fe, less than 0.05 percent of Si, less than 0.15 percent of impurity, and the balance of Al. The melting, homogenization and extrusion processes were the same as in example 1, and the extrusion pieces were processed under different heat treatment processes after being obtained by hot extrusion. Different schemes are selected, the influence of the final solid solution temperature, the influence of the high temperature aging temperature in the double-stage aging and the influence of the first-stage deep cooling, the second-stage deep cooling and the third-stage deep cooling processes are compared. The specific processes performed are shown in Table 3, and the results of the performance tests are shown in Table 4. From the performance test results, it can be seen that sample 15, the heat treatment process of the present invention, provides the best overall performance of the resulting aluminum alloy. FIG. 4 is a TEM image of a sample 15, and the result shows that the dispersion distribution of the metastable phase of the material matrix and the discontinuous distribution of the grain boundary stable phase are in discontinuous distribution, FIG. 5 is a BSK image of the sample 15 after three-stage solid solution, which shows that the supersaturation degree of the matrix is improved under the condition of no overburning due to the three-stage solid solution, and FIG. 6 is a scanning electron microscope image of the sample 15 after extrusion and cryogenic treatment, which shows that cryogenic treatment is favorable for recovery, residual stress is eliminated, and crystal grains are refined.
TABLE 3 samples of Al-Zn0.095-Mg0.025-Cu0.019 alloys obtained by different heat treatment processes (sample 15 obtained by the process according to the invention)
TABLE 4 comparison of the properties of Al-Zn0.095-Mg0.025-Cu0.019 alloy samples
Example 3: performance comparison of alloys of different compositions under the heat treatment process of the invention
Five ultra-high strength aluminum alloys (samples 17-21, see table 5) were designed according to the compositional design criteria of the present invention and were treated according to the heat treatment process set forth herein. Also, for comparison, the composition and properties of two alloys (samples 22-23, see Table 5) which were not designed with the main alloying elements according to the present invention are shown. After the alloy is smelted, melt is purified and grain is refined, the alloy is cast and formed, and then is subjected to demoulding and air cooling. The melting temperature is controlled at 750-770 ℃, and the measured liquid phase temperature is taken as the standard. The ingot casting adopts composite homogenization treatment: keeping the temperature at 430 ℃ for 46 hours, then heating to 467 ℃ and keeping the temperature for 4 hours, discharging from the furnace and air cooling. Hot extrusion is carried out at 420 ℃, and the temperature of an extrusion cylinder, a die and a cushion is 440 ℃. Then, the mixture is subjected to cryogenic treatment and is kept at-197 ℃ for 36 hours. Solid solution is carried out again, the temperature is kept at 470 ℃ for 40 minutes, then the temperature is increased to 480 ℃ and kept for 20 minutes, then the temperature is increased to 490 ℃ and kept for 20 minutes, and then water quenching is carried out. And (4) two-stage aging, namely, keeping the temperature at 135 ℃ for 16 hours, then heating to 190 ℃ and keeping the temperature for 10 minutes. And (4) carrying out cryogenic treatment, and keeping the temperature at-197 ℃ for 36 hours. The results of the sample property tests are shown in Table 6. The five alloys designed according to the invention (samples 17-21) all guaranteed yield strengths above 650MPa, tensile strengths above 650MPa, and elongations above 11%. Sample 20 has the highest content of the main alloy and therefore the highest volume fraction of strengthening phase, the corresponding highest strength and slightly lower elongation. Sample 17 had the lowest content of main alloy, and therefore the lowest volume fraction of strengthening phase, and the corresponding lowest strength. Sample 18 also has the same Cu content as sample 17, so the Zn content needs to be increased simultaneously with the increase of Mg content to ensure the comprehensive properties of the alloy. FIG. 8 is an as-cast backscattered electron photograph of sample 18, in which the increase in Zn content suppresses coarse S phase (Al)2CuMg) is generated. Sample 20 relative to sample18 and 19, have the same Cu content, so that the increase in Mg content must be accompanied by an increase in Zn content to ensure η phase (MgZn)2) Thereby ensuring the strength and plasticity of the alloy. FIG. 9 is a transmission electron microscope photograph of the sample 20 after final cryogenic cooling, in which the discontinuous distribution of the grain boundary precipitated phase can be clearly seen. Sample 22, which was not designed according to the present invention, had a high Cu content and a low Zn content, resulting in a strengthening phase S phase (Al)2CuMg) and theta phase (Al)2Cu) increases in composition, and η phase (MgZn)2) Sample 23 has an increased Zn content relative to alloy F, but still has a high Cu content and a low Zn content, albeit with an increased η phase (MgZn)2) But does not suppress the S phase (Al)2CuMg) and theta phase (Al)2Cu), and thus the strength is improved, but the elongation is not good. FIG. 9 is an as-cast backscattered electron photograph of sample 23, in which a coarse S phase (Al) can be seen2CuMg)。
TABLE 5 list of aluminium alloy compositions (wt%) obtained according to the treatment process of the invention
TABLE 6 tabulated aluminum alloy properties obtained by the treatment process of the present invention
Claims (9)
1. A preparation method of Al-Zn-Mg-Cu series ultrahigh-strength aluminum alloy is characterized by comprising the following steps:
(1) preparing materials according to alloy components, smelting, purifying melt, refining crystal grains, casting and forming to form cast ingots, demoulding and air cooling: the melting temperature is controlled at 750-770 ℃, and N is adopted for melt purification2Refining;
(2) carrying out composite homogenization treatment on the cast ingot obtained in the step (1): keeping the temperature at 430 ℃ for 46 hours, heating to 467 ℃, keeping the temperature for 4 hours, and then discharging from the furnace and air cooling;
(3) carrying out hot extrusion on the cast ingot subjected to the composite homogenization treatment in the step (2): during extrusion, the metal temperature is 400-440 ℃, and the heating time is 2 h; the temperature of the extrusion cylinder, the die and the cushion is 440-480 ℃, and the heating time is 12 h;
(4) and (3) carrying out cryogenic treatment on the extruded part obtained in the step (3): keeping the temperature at-197 ℃ for 36 hours;
(5) carrying out three-stage solid solution on the subzero treatment sample obtained in the step (4): keeping the temperature of 450-470 ℃ for 20-40 minutes, heating to 470-480 ℃, keeping the temperature for 20 minutes, heating to 480-490 ℃, keeping the temperature for 20 minutes, and then performing water quenching or oil quenching;
(6) and (3) carrying out double-stage aging on the solid solution sample obtained in the step (5): keeping the temperature of 120-135 ℃ for 12 hours, heating to 180-190 ℃, keeping the temperature for 10 minutes, heating to 190 ℃, and keeping the temperature for 20 minutes;
(7) and (4) carrying out cryogenic treatment on the aging sample obtained in the step (6) again: the temperature was maintained at-197 ℃ for 36 hours.
2. An Al-Zn-Mg-Cu based ultra-high strength aluminum alloy produced by the method according to claim 1, wherein: the aluminum alloy comprises the following components in percentage by mass: 7.2-9.5% of Zn, 1.2-2.5% of Mg, 1.3-1.9% of Cu, 0.08-0.15% of ZrC, 0.05% of Ti, 0.05% of Mn, 0.04% of Cr, 0.05% of Fe, 0.05% of Si, 0.15% of total impurities and the balance of Al.
3. An Al-Zn-Mg-Cu based ultra-high strength aluminum alloy produced by the method according to claim 1, wherein: the aluminum alloy comprises the following components in percentage by mass: 8.5 percent of Zn, 2.0 percent of Mg, 1.5 percent of Cu, 0.12 percent of Zr, 0.05 percent of Ti0, 0.05 percent of Mn, 0.04 percent of Cr, less than 0.05 percent of Fe, less than 0.05 percent of Si, less than 0.15 percent of impurity, and the balance of Al.
4. An Al-Zn-Mg-Cu based ultra-high strength aluminum alloy produced by the method according to claim 1, wherein: the aluminum alloy comprises the following components in percentage by mass: 9.5 percent of Zn, 2.5 percent of Mg, 1.9 percent of Cu, 0.15 percent of Zr, 0.05 percent of Ti0, 0.05 percent of Mn, 0.04 percent of Cr, less than 0.05 percent of Fe, less than 0.05 percent of Si, less than 0.15 percent of impurity, and the balance of Al.
5. An Al-Zn-Mg-Cu based ultra-high strength aluminum alloy produced by the method according to claim 1, wherein: the aluminum alloy comprises the following components in percentage by mass: 8.0 percent of Zn, 2.0 percent of Mg, 1.9 percent of Cu, 0.15 percent of Zr, 0.05 percent of Ti0, 0.05 percent of Mn, 0.04 percent of Cr, less than 0.05 percent of Fe, less than 0.05 percent of Si, less than 0.15 percent of impurity, and the balance of Al.
6. An Al-Zn-Mg-Cu based ultra-high strength aluminum alloy produced by the method according to claim 1, wherein: the aluminum alloy comprises the following components in percentage by mass: 8.5 percent of Zn, 2.2 percent of Mg, 1.9 percent of Cu, 0.15 percent of Zr, 0.05 percent of Ti0, 0.05 percent of Mn, 0.04 percent of Cr, less than 0.05 percent of Fe, less than 0.05 percent of Si, less than 0.15 percent of impurity, and the balance of Al.
7. An Al-Zn-Mg-Cu based ultra-high strength aluminum alloy produced by the method according to claim 1, wherein: the aluminum alloy comprises the following components in percentage by mass: 8.7 percent of Zn, 2.3 percent of Mg, 1.8 percent of Cu, 0.15 percent of Zr, 0.05 percent of Ti0, 0.05 percent of Mn, 0.04 percent of Cr, less than 0.05 percent of Fe, less than 0.05 percent of Si, less than 0.15 percent of impurity, and the balance of Al.
8. An Al-Zn-Mg-Cu based ultra-high strength aluminum alloy produced by the method according to claim 1, wherein: the aluminum alloy comprises the following components in percentage by mass: 9.3 percent of Zn, 2.5 percent of Mg, 1.8 percent of Cu, 0.15 percent of Zr, 0.05 percent of Ti0, 0.05 percent of Mn, 0.04 percent of Cr, less than 0.05 percent of Fe, less than 0.05 percent of Si, less than 0.15 percent of impurity, and the balance of Al.
9. An Al-Zn-Mg-Cu based ultra-high strength aluminum alloy produced by the method according to claim 1, wherein: the aluminum alloy comprises the following components in percentage by mass: 9.0 percent of Zn, 2.4 percent of Mg, 1.8 percent of Cu, 0.15 percent of Zr, 0.05 percent of Ti0, 0.05 percent of Mn, 0.04 percent of Cr, less than 0.05 percent of Fe, less than 0.05 percent of Si, less than 0.15 percent of impurity, and the balance of Al.
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| CN110714150B (en) * | 2019-10-15 | 2021-01-12 | Oppo广东移动通信有限公司 | Aluminum alloy and preparation method thereof, electronic equipment structural member and electronic equipment |
| CN111020423A (en) * | 2019-12-27 | 2020-04-17 | 北京首航科学技术开发有限公司 | Light ultrahigh-strength aluminum alloy nut and aluminum alloy material |
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| CN112795856B (en) * | 2020-12-25 | 2021-10-08 | 国家高速列车青岛技术创新中心 | Heat treatment method for cast aluminum alloy casting and cast aluminum alloy casting obtained by heat treatment method |
| CN112813321B (en) * | 2020-12-31 | 2022-04-05 | 安徽鑫铂铝业股份有限公司 | High-strength and high-toughness aluminum profile for rail transit |
| CN113308652B (en) * | 2021-04-27 | 2022-10-25 | 沈阳工业大学 | Corrosion-resistant strengthening process combining regression and reaging of aluminum alloy and cryogenic treatment |
| CN113755769B (en) * | 2021-08-13 | 2022-04-08 | 上海交通大学 | High-strength high-toughness aluminum-based composite material and heat treatment method |
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