CN111485187A - Non-isothermal overaging treatment method for large-diameter AlZnMgCu alloy extrusion rod - Google Patents
Non-isothermal overaging treatment method for large-diameter AlZnMgCu alloy extrusion rod Download PDFInfo
- Publication number
- CN111485187A CN111485187A CN202010250906.4A CN202010250906A CN111485187A CN 111485187 A CN111485187 A CN 111485187A CN 202010250906 A CN202010250906 A CN 202010250906A CN 111485187 A CN111485187 A CN 111485187A
- Authority
- CN
- China
- Prior art keywords
- aging
- alloy extrusion
- extrusion rod
- alznmgcu
- alznmgcu alloy
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22F—CHANGING THE PHYSICAL STRUCTURE OF NON-FERROUS METALS AND NON-FERROUS ALLOYS
- C22F1/00—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working
- C22F1/04—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working of aluminium or alloys based thereon
- C22F1/053—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working of aluminium or alloys based thereon of alloys with zinc as the next major constituent
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
- C21D9/0075—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for rods of limited length
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C21/00—Alloys based on aluminium
- C22C21/10—Alloys based on aluminium with zinc as the next major constituent
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22F—CHANGING THE PHYSICAL STRUCTURE OF NON-FERROUS METALS AND NON-FERROUS ALLOYS
- C22F1/00—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working
- C22F1/002—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working by rapid cooling or quenching; cooling agents used therefor
Abstract
The invention discloses a non-isothermal overaging treatment method of a larger-diameter AlZnMgCu alloy extrusion rod, which comprises the steps of firstly carrying out solution quenching treatment on the larger-diameter AlZnMgCu alloy extrusion rod to be treated, then carrying out first-stage preaging treatment according to underaging below the highest aging temperature point strengthening effect, secondly, the large-diameter AlZnMgCu alloy extrusion bar which is subjected to the pre-aging treatment in the first stage is heated to the highest aging temperature point at a certain heating rate, and then is immediately cooled to room temperature at a certain cooling rate, the method reasonably utilizes the difference of the heating and cooling rates of the surface layer and the core part of the extrusion bar to balance the actual aging effects of different layers by the heating and cooling aging technology, the strength and the stress corrosion resistance of the material are improved, the radial structure uniformity and the performance uniformity of the AlZnMgCu alloy extrusion bar with larger diameter can be improved, and the method is suitable for aging heat treatment of the AlZnMgCu alloy extrusion bar with larger diameter.
Description
Technical Field
The invention relates to a non-isothermal overaging treatment method for an AlZnMgCu alloy extrusion rod with a larger diameter, belonging to the technical field of heat treatment strengthening of aluminum alloy.
Background
The method for preparing the bearing structural member by directly manufacturing the high-strength AlZnMgCu alloy extrusion rod or matching with machining and the like is one of important ways for realizing the light weight of the structures of the rapid rail transit and the aircraft. With the continuous promotion of China high-speed trains and 'big airplanes' plans, the continuous improvement of the carrying capacity and the performance of the transportation means puts more strict requirements on the comprehensive performances of structure weight reduction, bar extrusion and the like.
As a typical precipitation strengthening alloy, the comprehensive performance of a high-quality AlZnMgCu alloy extrusion rod strongly depends on an aging technology. However, single-stage peak aging can only maximize the strength of the AlZnMgCu alloy. The result of improving the stress corrosion resistance of the alloy by isothermal two-stage overaging is based on the premise of sacrificing the mechanical property of the alloy. The regression and reaging only theoretically solves the possibility that the strength and the corrosion resistance of the AlZnMgCu alloy can be synergistically improved, but the process window is narrow, and the industrial application difficulty is extremely high. Therefore, the synergistic improvement of the mechanical property and the stress corrosion resistance of the AlZnMgCu alloy is a key technical difficulty to be solved by the aging heat treatment of the alloy.
In addition, along with the continuous deepening of the attention degree of the near net shape and the integral manufacturing concept, the aging heat treatment of the large-size AlZnMgCu alloy structural member also has the problem of non-uniformity of structure and performance caused by the difference of the aging degree of the core part and the surface layer of the thick-section structural member, such as a high-performance light extrusion bar used for a high-speed railway and large-size aerospace equipment, and the breakthrough of the mechanical and corrosion performance level and uniformity of the product plays a key role in meeting the ultra-strong light structural member urgently needed in the fields of high-speed rail transit and aerospace in China. Therefore, the heat treatment strengthening treatment of the AlZnMgCu alloy extrusion rod with larger diameter can achieve the following two purposes: (1) meanwhile, the material has high mechanical property and stress corrosion resistance; (2) the radial non-uniformity of performance is low.
Disclosure of Invention
Aiming at the defects and shortcomings of the conventional two-stage aging heat treatment, the invention provides a non-isothermal overaging treatment method for a large-diameter AlZnMgCu alloy extrusion rod, which solves the problems in the background technology.
The method starts from the optimized matching of four factors of the heating rate, the highest aging temperature point and the cooling rate of the cooling aging in the first-stage pre-aging and the second-stage heating aging, firstly, GP zones, η' phases and grain boundary η phases with certain proportions are precipitated in alloy crystal through the first-stage pre-aging, secondly, the heating rate and the highest aging temperature point of the second-stage heating aging are matched, coarsening and discontinuity of the grain boundary η phases are promoted while coarsening of semi-coherent phases in the crystal is inhibited, secondly, the temperature is reduced to room temperature at a certain cooling rate, and secondly, the matrix is strengthened by re-desolvation of supersaturated solid solution, and meanwhile, the mutual compensation effect of the heating and cooling rates of a large-diameter extrusion bar surface layer and a core part is utilized to achieve the purposes of controlling the sizes of precipitation phases of the crystal inner and the grain boundary and the optimized distribution of the precipitation phases in the radial direction of the bar, so as to effectively improve.
The invention relates to a non-isothermal overaging treatment method of an AlZnMgCu alloy extrusion rod with a larger diameter, which comprises the following steps:
(1) obtaining an AlZnMgCu alloy extrusion bar with the diameter of 60-80 mm under the condition of extrusion ratio of 15-18. And carrying out solution treatment on the extruded bar. The solid solution temperature is 470-480 ℃, the solid solution time is 1-2 h, and the quenching transfer time is less than or equal to 10 s;
(2) and carrying out first-stage pre-aging treatment on the AlZnMgCu alloy extrusion rod with larger diameter in a solid solution state according to underaging of the strengthening effect below the maximum aging temperature point. The pre-aging temperature of the first stage is less than or equal to 120 ℃, and the pre-aging time of the first stage is less than or equal to 24 hours;
(3) the temperature rise rate of the second-stage temperature rise and aging is 60-300 ℃/h, the heating is carried out to the preset highest aging temperature point of 215-250 ℃, the isothermal heat preservation platform of the second-stage aging is cancelled, and the temperature is immediately reduced and aged at the cooling rate of 60-120 ℃/h after the temperature is raised to the preset highest aging temperature point.
The invention has the beneficial effects that:
the inventors found in the research that the alloy has a certain proportion of GP zone and η ' phase precipitated in the crystal by the first stage of pre-aging, and η equilibrium phase precipitated in the grain boundary, and in the second stage of temperature-raising aging, the GP zone and η ' phase evolved into η ' and η phases, and the grain boundary phase η completed the coarsening and interruption process, wherein in the cooling aging stage, the alloy hardness is increased along with the re-precipitation of the intragranular nonequilibrium phase, and the grain boundary η phase continues coarsening and interruption in the high temperature stage of cooling, so that the alloy conductivity is continuously increased, wherein the aging structure state in the first stage has an important influence on the temperature-raising aging behavior.
Drawings
FIG. 1 is a schematic view of the process of the present invention.
Detailed Description
The following detailed description of the preferred embodiments of the present invention is provided to enable those skilled in the art to more readily understand the advantages and features of the present invention and to thereby define the scope of the invention more clearly.
According to the comparative example and the embodiment of the invention, the hot extrusion Al8Zn2Mg2Cu aluminum alloy bar with the diameter of 60mm and the extrusion ratio of 15 is adopted, the solid solution heat treatment process is 470 ℃,1h +480 ℃,1h, the room temperature water quenching is carried out after the solid solution, and the quenching transfer time is less than 10 s. Then, different aging treatments are respectively carried out on the samples of the comparative examples and the examples, after the treatments are finished, the conductivity, the hardness and the tensile mechanical property of all the samples of the examples and the comparative examples are detected, and the performance test results are shown in tables 1 and 2.
Comparative example 1:
the extruded rod is aged by adopting a single-stage (120 ℃/24) peak aging mode. After the aging, hardness and conductivity tests were performed, and the test results are shown in table 1. The peak aged samples were then tested for room temperature tensile properties and the results are shown in table 2.
Comparative example 2:
the sample is aged by adopting an isothermal two-stage (120 ℃/12h +160 ℃/18h) overaging mode. After the aging, hardness and conductivity tests were performed, and the test results are shown in table 1. The room temperature tensile properties of the two stage aged samples were then tested and the results are shown in table 2.
Example 1:
the pre-aging sample treated by natural aging (room temperature/24 h) is heated to 215 ℃ at a heating rate of 60 ℃/h, and furnace cooling aging is started immediately after the temperature is reached, wherein the cooling rate is 80 ℃/h. After aging, hardness and conductivity tests were performed, and the test results are shown in table 1. The samples were tested for tensile properties at room temperature and the results are shown in table 2.
Example 2:
for the pre-aging sample treated by natural aging (room temperature/24 h), the temperature is increased to 225 ℃ at the heating rate of 180 ℃/h, and furnace cooling aging is started immediately after the temperature is reached, wherein the cooling rate is 80 ℃/h. After aging, hardness and conductivity tests were performed, and the test results are shown in table 1. The samples were tested for tensile properties at room temperature and the results are shown in table 2.
Example 3:
heating the preaging sample treated at 105 ℃/24h to 215 ℃ at a heating rate of 60 ℃/h, immediately cooling in a furnace for ageing after reaching the temperature, wherein the cooling rate is 80 ℃/h. After aging, hardness and conductivity tests were performed, and the test results are shown in table 1. The samples were tested for tensile properties at room temperature and the results are shown in table 2.
Example 4:
heating the preaging sample treated at 105 ℃/24h to 225 ℃ at a heating rate of 180 ℃/h, immediately cooling and aging in a furnace after reaching the temperature, wherein the cooling rate is 80 ℃/h. After aging, hardness and conductivity tests were performed, and the test results are shown in table 1. The samples were tested for tensile properties at room temperature and the results are shown in table 2.
Example 5:
heating the pre-aging sample treated at 120 ℃/24h to 215 ℃ at a heating rate of 60 ℃/h, immediately cooling in a furnace after reaching the temperature, and performing aging at a cooling rate of 80 ℃/h. After aging, hardness and conductivity tests were performed, and the test results are shown in table 1. The samples were tested for tensile properties at room temperature and the results are shown in table 2.
Example 6:
heating the pre-aged sample treated at 120 ℃/24h to 225 ℃ at a heating rate of 180 ℃/h, immediately cooling in a furnace after reaching the temperature, and aging at a cooling rate of 80 ℃/h. After aging, hardness and conductivity tests were performed, and the test results are shown in table 1. The samples were tested for tensile properties at room temperature and the results are shown in table 2.
Using TecnaiG2The results of 20-type high-resolution transmission electron microscope detection of microstructures of AlZnMgCu alloys under different non-isothermal overaging indicate that an intragranular precipitated phase is mainly an η' phase and comprises a certain amount of GP zones and a small amount of η phases, and coarse discontinuous η phases exist on grain boundaries, so that the microstructure characteristics can effectively ensure the mechanical property, effectively cut off stress corrosion channels and improve the corrosion resistance of an extrusion rodThe tensile strength of the extruded bar obtained by temperature overaging is about 650MPa, and the electric conductivity is higher than 38% IACS.
In conclusion, through the non-isothermal overaging treatment provided by the invention, the AlZnMgCu alloy extrusion bar with larger diameter can obtain excellent mechanical and stress corrosion resistance, and has wide application prospect in the fields of high-speed rail transit and aerospace.
The above disclosure is intended only to be exemplary of the present application and any process variations falling within the scope of the present application are intended to be within the scope of the present application.
TABLE 1 comparison of conductivity and hardness of samples of different heat treatment regimes
TABLE 2 comparison of mechanical properties at room temperature for samples of different heat treatment systems
Claims (8)
1. A non-isothermal overaging treatment method for an AlZnMgCu alloy extrusion rod with a larger diameter is characterized by comprising the following steps:
(1) carrying out solution quenching treatment on the AlZnMgCu alloy extrusion rod with larger diameter to be treated, and then carrying out first-stage pre-aging treatment according to underaging below the highest aging temperature strengthening effect;
(2) heating the large-diameter AlZnMgCu alloy extrusion rod subjected to the pre-aging treatment in the first stage to the maximum aging temperature point at a certain heating rate, and then immediately cooling to room temperature at a certain cooling rate.
2. The non-isothermal overaging treatment method of the AlZnMgCu alloy extrusion rod with the larger diameter according to claim 1, characterized in that: the extrusion ratio of the AlZnMgCu alloy extrusion rod is 15-18, and the diameter is 60-80 mm.
3. The non-isothermal overaging treatment method of the AlZnMgCu alloy extrusion rod with the larger diameter according to claim 1, characterized in that: the solid solution temperature is 470-480 ℃, and the solid solution time is 1-2 h.
4. The non-isothermal overaging treatment method of the AlZnMgCu alloy extrusion rod with the larger diameter according to claim 1, characterized in that: the quenching transfer time is less than or equal to 10 s.
5. The non-isothermal overaging treatment method of the AlZnMgCu alloy extrusion rod with the larger diameter according to claim 1, characterized in that: the pre-aging temperature of the first stage is less than or equal to 120 ℃, and the pre-aging time of the first stage is less than or equal to 24 hours.
6. The non-isothermal overaging treatment method of the AlZnMgCu alloy extrusion rod with the larger diameter according to claim 1, characterized in that: the heating rate of the heating stage is 60-300 ℃/h.
7. The non-isothermal overaging treatment method of the AlZnMgCu alloy extrusion rod with the larger diameter according to claim 1, characterized in that: the maximum aging temperature point is 210-250 ℃.
8. The non-isothermal overaging treatment method of the AlZnMgCu alloy extrusion rod with the larger diameter according to claim 1, characterized in that: the cooling rate of the cooling stage is 60-120 ℃/h.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010250906.4A CN111485187A (en) | 2020-04-01 | 2020-04-01 | Non-isothermal overaging treatment method for large-diameter AlZnMgCu alloy extrusion rod |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010250906.4A CN111485187A (en) | 2020-04-01 | 2020-04-01 | Non-isothermal overaging treatment method for large-diameter AlZnMgCu alloy extrusion rod |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN111485187A true CN111485187A (en) | 2020-08-04 |
Family
ID=71812477
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010250906.4A Withdrawn CN111485187A (en) | 2020-04-01 | 2020-04-01 | Non-isothermal overaging treatment method for large-diameter AlZnMgCu alloy extrusion rod |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111485187A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113430433A (en) * | 2021-08-25 | 2021-09-24 | 中国航发北京航空材料研究院 | Aging treatment method of aluminum alloy component |
| CN115287508A (en) * | 2022-09-14 | 2022-11-04 | 东莞市青鸟金属材料有限公司 | High-strength high-heat-conductivity die-casting aluminum alloy and heat treatment method thereof |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20100224293A1 (en) * | 2009-03-05 | 2010-09-09 | Gm Global Technology Operations, Inc. | Methods for strengthening slowly-quenched/cooled cast aluminum components |
| CN103436826A (en) * | 2013-07-30 | 2013-12-11 | 中南大学 | Third-level aging method of Al-Zn-Mg-Cu-Zr alloy thick-section member |
| CN109207888A (en) * | 2018-09-27 | 2019-01-15 | 西北工业大学 | A kind of efficient creep age forming method of Al-Zn-Mg-Cu aluminum alloy plate non-isothermal |
-
2020
- 2020-04-01 CN CN202010250906.4A patent/CN111485187A/en not_active Withdrawn
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20100224293A1 (en) * | 2009-03-05 | 2010-09-09 | Gm Global Technology Operations, Inc. | Methods for strengthening slowly-quenched/cooled cast aluminum components |
| CN103436826A (en) * | 2013-07-30 | 2013-12-11 | 中南大学 | Third-level aging method of Al-Zn-Mg-Cu-Zr alloy thick-section member |
| CN109207888A (en) * | 2018-09-27 | 2019-01-15 | 西北工业大学 | A kind of efficient creep age forming method of Al-Zn-Mg-Cu aluminum alloy plate non-isothermal |
Non-Patent Citations (1)
| Title |
|---|
| 王国迎: "《非等温回归及再时效对7055铝合金组织和性能的影响》", 《中国优秀硕士学位论文全文数据库 工程技术Ⅰ辑》 * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113430433A (en) * | 2021-08-25 | 2021-09-24 | 中国航发北京航空材料研究院 | Aging treatment method of aluminum alloy component |
| CN115287508A (en) * | 2022-09-14 | 2022-11-04 | 东莞市青鸟金属材料有限公司 | High-strength high-heat-conductivity die-casting aluminum alloy and heat treatment method thereof |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Huang et al. | Optimizing the strength, ductility and electrical conductivity of a Cu-Cr-Zr alloy by rotary swaging and aging treatment | |
| Kim et al. | Optimization of strength and ductility of 2024 Al by equal channel angular pressing (ECAP) and post-ECAP aging | |
| Ji et al. | Microstructures and properties of Al–Mg–SI alloy overhead conductor by horizontal continuous casting and continuous extrusion forming process | |
| CN110846599B (en) | Heat treatment method for improving corrosion performance of 800 MPa-grade aluminum alloy | |
| CN109023180B (en) | Aging heat treatment method of 7 series aluminum alloy | |
| CN111485187A (en) | Non-isothermal overaging treatment method for large-diameter AlZnMgCu alloy extrusion rod | |
| CN109628861B (en) | Heat treatment method for synchronously improving strength and elongation of 7-series aluminum alloy plate | |
| Liao et al. | Effect of thermo-electropulsing rolling on mechanical properties and microstructure of AZ31 magnesium alloy | |
| CN108085627B (en) | A kind of deformation heat treatment method of Mg-Al system precipitation strength type magnesium alloy | |
| CN108359863B (en) | GIS pipe shell production process | |
| KR20100120644A (en) | Copper-nickel-silicon alloys | |
| CN110586828B (en) | Free forging method of Ti662 titanium alloy large-size bar | |
| Zhang et al. | Effect of multi-stage aging treatments on the precipitation and mechanical properties of Al-Zn-Mg alloys | |
| CN113201703B (en) | Aluminum alloy ingot casting homogenizing annealing stepped cooling process | |
| Shen et al. | Grain refinement and enhanced precipitation of Cu–Cr–Zr induced by hot rolling with intermediate annealing treatment | |
| CN102586655A (en) | Process for strengthening Al-Sc-Zr conduction alloy and optimizing conductivity | |
| CN110541131B (en) | Al-Cu-Li alloy thermomechanical treatment process based on particle-excited nucleation | |
| CN116555647A (en) | Production process of high-precision 2014 aluminum alloy turbine blade for aviation | |
| CN106521380A (en) | Hot quenching new process and application of large-size high-strength aluminum alloy forgings | |
| CN113373360B (en) | Method for improving strength and corrosion resistance of AZ series wrought magnesium alloy | |
| CN115261752A (en) | High-strength 2024 aluminum alloy processing technology and high-strength 2024 aluminum alloy | |
| CN204589277U (en) | A kind of on-lining soften annealing system of industrially pure titanium band | |
| CN110819857B (en) | Rail train automobile body thin-wall aluminum profile | |
| CN110129699B (en) | High-uniform-elongation GPa-grade titanium and preparation method thereof | |
| CN112553553A (en) | Ti2AlNb alloy cold-rolled foil and preparation method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| WW01 | Invention patent application withdrawn after publication | ||
| WW01 | Invention patent application withdrawn after publication |
Application publication date: 20200804 |