A method for preparing a high-toughness high-aluminum zinc alloy plate

Abstract

The application discloses a high-strength and high-toughness high-aluminum zinc alloy plate preparation method, which comprises the following steps: S1, taking zinc alloy raw materials according to a proportion, melting to obtain zinc alloy ingots, and processing the zinc alloy ingots into zinc alloy raw material plates with a thickness of 4mm-8mm; the zinc alloy ingots comprise the following components in percentage by weight: 3%-8% of aluminum, 0.5%-2% of copper, 0.05%-0.15% of titanium, 0.01%-0.2% of magnesium, <0.05% of impurities, and the balance of zinc; S2, uniformly heat treating the zinc alloy raw material plates at a temperature of 280 DEG C-330 DEG C; S3, sequentially heat rolling and cold rolling the zinc alloy raw material plates to obtain zinc alloy slabs; and S4, annealing the zinc alloy slabs to obtain zinc alloy plates. Compared with the prior art, the application solves the problems of insufficient strength and toughness of the zinc alloy plates prepared by the existing preparation method.

Description

Technical Field

[0001] This invention relates to the field of zinc alloy processing technology, and in particular to a method for preparing high-strength and high-toughness high-aluminum zinc alloy plates. Background Technology

[0002] Zinc has a melting point of around 419.5℃, and this low melting point means that it requires less energy to melt. At the same time, zinc alloys have excellent machinability; castings undergoing deformation processing experience almost no work hardening, resulting in minimal damage to machining tools. This ease of machining significantly reduces manufacturing costs in industrial production.

[0003] Zinc alloy sheets are widely used in many fields such as construction, automobiles, electronics, and industrial manufacturing due to their good corrosion resistance, high strength, and easy processing. The construction industry is the most widely used field for zinc alloy sheets.

[0004] The existing mass production technology for zinc alloy sheets in China is still immature, resulting in zinc alloy sheets with low strength, which greatly limits the application range of zinc alloy sheets. Summary of the Invention

[0005] The purpose of this invention is to provide a method for preparing high-strength and high-toughness high-aluminum zinc alloy plates, so as to solve the problem of insufficient strength and toughness of zinc alloy plates prepared by existing methods.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: a method for preparing high-strength and high-toughness high-aluminum-zinc alloy plates, comprising the following steps:

[0007] S1. Take zinc alloy raw materials according to the formula, smelt them to obtain zinc alloy ingots, and process the zinc alloy ingots into zinc alloy raw material plates with a thickness of 4mm-8mm. The zinc alloy ingots include the following components by weight percentage: aluminum 3%-8%, copper 0.5%-2%, titanium 0.05%-0.15%, magnesium 0.01%-0.2%, impurities <0.05%, and the balance is zinc.

[0008] S2. The zinc alloy raw material plate is subjected to homogenization heat treatment at a temperature of 280℃-330℃ to relax the stress and facilitate subsequent rolling with large deformation.

[0009] S3. The zinc alloy raw material plate is hot-rolled and cold-rolled in sequence to obtain a zinc alloy slab.

[0010] S4. Anneal the zinc alloy slab to obtain zinc alloy sheet.

[0011] As a further description of the above technical solution:

[0012] In step S1, the zinc alloy ingot is smelted using a covering agent protection method. Alloying elements are added in the form of pure zinc, pure aluminum, pure copper, pure magnesium, and copper-titanium master alloy. The smelting temperature is 500℃-700℃, and the casting temperature is 430℃-470℃.

[0013] As a further description of the above technical solution:

[0014] In step S1, the zinc alloy ingot is a square casting, which is cut into several zinc alloy sheets, and the surface of the zinc alloy sheets is ground using a grinding machine to obtain a zinc alloy raw material plate with a thickness of 4mm-8mm.

[0015] As a further description of the above technical solution:

[0016] In step S3, the rolling process of the zinc alloy slab includes the following steps:

[0017] S31. Preheating: The zinc alloy raw material plate is preheated before hot rolling at a temperature of 240℃-320℃ for 0.5h-2h.

[0018] S32, Hot Rolled: The rolling deformation in a single pass is 20%-40%, and the total deformation in hot rolling is 70%-90%;

[0019] S33, Cold rolling: The deformation amount of a single pass is 20% to 50%, and the total deformation amount of cold rolling is 60% to 80%.

[0020] As a further description of the above technical solution:

[0021] In step S4, when the zinc alloy slab is annealed in the annealing furnace, the annealing temperature is 120℃~180℃ and the annealing time is 0.5~3h.

[0022] As a further description of the above technical solution:

[0023] In step S4, the zinc alloy slab is cooled to room temperature by furnace cooling or air cooling.

[0024] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0025] 1. In this invention, the zinc alloy sheet composition is enhanced by adding a high content of aluminum to increase the strength of the alloy, and by adding copper and titanium to further improve the strength and toughness of the alloy. At the same time, the rolling process and annealing process are combined to prepare a high-strength and high-toughness rolled zinc alloy sheet with a strength of 320-380MPa and an elongation after fracture of 5%-10%, which further improves the performance of the zinc alloy sheet.

[0026] 2. In this invention, zinc alloy sheets are prepared through hot rolling, cold rolling, and annealing. In the hot rolling stage of the rolling process, the grains are broken and a deformation texture is initially formed, which improves the strength and toughness of the zinc alloy. In the cold rolling stage, as the deformation increases, a large number of slip bands and twin bands appear inside the grains, which improves the strength and hardness of the material. High-strength and high-toughness rolled zinc alloy sheets are prepared through hot rolling with large deformation and cold rolling with large deformation.

[0027] 3. In this invention, a high content of aluminum is added to the zinc alloy sheet, which reduces the alloy density and achieves lightweighting of the zinc alloy sheet, making it particularly suitable for building materials such as door and window profiles and roof / wall cladding. Attached Figure Description

[0028] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 Optical microstructure of zinc alloy sheet prepared by a method for producing high-strength and high-toughness high-aluminum zinc alloy sheet. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] Example 1

[0032] Please see Figure 1 This invention provides a method for preparing high-strength and high-toughness high-aluminum-zinc alloy plates, comprising the following steps:

[0033] S1. Take zinc alloy raw materials according to the formula, smelt them to obtain zinc alloy ingots, and process the zinc alloy ingots into zinc alloy raw material plates with a thickness of 4mm-8mm. The zinc alloy ingots include the following components by weight percentage: aluminum 3%-8%, copper 0.5%-2%, titanium 0.05%-0.15%, magnesium 0.01%-0.2%, impurities <0.05%, and the balance is zinc.

[0034] S2. The zinc alloy raw material plate is subjected to homogenization heat treatment at a temperature of 280℃-330℃.

[0035] S3. The zinc alloy raw material plate is hot-rolled and cold-rolled in sequence to obtain a zinc alloy slab.

[0036] S4. Anneal the zinc alloy slab. When annealing the zinc alloy slab in the annealing furnace, the annealing temperature is 120℃~180℃ and the annealing time is 0.5~3h. Afterwards, it is cooled to room temperature by furnace cooling or air cooling to obtain zinc alloy sheet.

[0037] In step S1, the zinc alloy ingot is smelted using a covering agent protection method. Alloying elements are added in the form of pure zinc, pure aluminum, pure copper, pure magnesium, and a copper-titanium master alloy. The smelting temperature is 500℃-700℃, and the casting temperature is 430℃-470℃. The resulting zinc alloy ingot is a square ingot, which is cut into several zinc alloy sheets. The surface of the zinc alloy sheets is then ground using a grinding machine to obtain zinc alloy raw material plates with a thickness of 4mm-8mm. Small batches of high-precision zinc alloy sheet samples can be processed using wire cutting, while for batch processing, the zinc alloy ingot can be blanked using a high-speed circular saw.

[0038] In step S3, the rolling process of the zinc alloy slab includes the following steps:

[0039] S31. Preheating: The zinc alloy raw material plate is preheated before hot rolling at a temperature of 240℃-320℃ for 0.5h-2h.

[0040] S32, Hot Rolled: The rolling deformation in a single pass is 20%-40%, and the total deformation in hot rolling is 70%-90%;

[0041] S33, Cold rolling: The deformation amount of a single pass is 20% to 50%, and the total deformation amount of cold rolling is 60% to 80%.

[0042] This invention achieves the preparation of zinc alloy sheets through hot rolling, cold rolling, and annealing. In the hot rolling stage of the rolling process, the grains are broken and a deformation texture is initially formed, which improves the strength and toughness of the zinc alloy. In the cold rolling stage, as the deformation increases, a large number of slip bands and twin bands appear inside the grains, which improves the strength and hardness of the material. High-strength and high-toughness rolled zinc alloy sheets are prepared by hot rolling and cold rolling with large deformation.

[0043] In the composition of zinc alloy sheets, the strength of the alloy is enhanced by adding a high content of aluminum, and the strength and toughness of the alloy are further improved by adding copper and titanium. At the same time, the rolling process and annealing process are combined to prepare high-strength and high-toughness rolled zinc alloy sheets with a strength of 320-380MPa and an elongation after fracture of 5%-10%, which further improves the performance of zinc alloy sheets.

[0044] In addition, the addition of a high aluminum content to zinc alloy sheets reduces the alloy density, achieving lightweight zinc alloy sheets, which are especially suitable for building materials such as door and window profiles, roofing / wall cladding, etc.

[0045] Mechanism of action of various components in zinc alloys:

[0046] <1> In zinc alloys, aluminum mainly exists as the aluminum-rich α-Al phase and lamellar eutectic structure. A small amount of aluminum is dissolved in the zinc matrix, which plays a role in solid solution strengthening and improves the strength and toughness of zinc alloys.

[0047] <2> Copper in zinc alloys forms CuZn4 phase with zinc, which improves the strength, toughness and wear resistance of zinc alloys. However, excessive copper will affect the toughness and dimensional stability of the alloy.

[0048] <3> Titanium forms Al3Ti with aluminum in zinc alloys, which increases the nucleation rate of zinc alloys, thereby refining the matrix structure and improving the hardness, strength and toughness of zinc alloys.

[0049] <4> Even trace amounts of magnesium can have a significant impact on zinc alloys, noticeably improving their overall mechanical properties and inhibiting intergranular corrosion. However, it is important to avoid excessive magnesium content, which can damage the overall mechanical properties of zinc alloys.

[0050] See Figure 1 The figure shows the optical microstructure of the zinc alloy sheet. It can be seen that the matrix has obvious texture along the rolling direction and contains black blocky Al3Ti second phase, which breaks into fine second phase after rolling.

[0051] The zinc alloy sheet prepared in Example 1 was processed into three independent parallel test specimens, and tensile tests were performed.

[0052] The test results are shown in Table 1.

[0053] Table 1: Tensile test results of specimens 1-3

[0054] Table 1 shows the test results for tensile properties. Based on this, the zinc alloy sheet has a tensile strength of 320 MPa, a yield strength of 315 MPa, and an elongation of 8%, exhibiting both high strength and good plasticity.

[0055] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for preparing a high-strength and high-toughness high-aluminum-zinc alloy sheet, characterized in that, Includes the following steps: S1. Take zinc alloy raw materials according to the formula, smelt them to obtain zinc alloy ingots, and process the zinc alloy ingots into zinc alloy raw material plates with a thickness of 4mm-8mm. The zinc alloy ingots include the following components by weight percentage: aluminum 3%-8%, copper 0.5%-2%, titanium 0.05%-0.15%, magnesium 0.01%-0.2%, impurities <0.05%, and the balance is zinc. S2. The zinc alloy raw material plate is subjected to homogenization heat treatment at a temperature of 280℃-330℃. S3. The zinc alloy raw material plate is hot-rolled and cold-rolled in sequence to obtain a zinc alloy slab. S4. Anneal the zinc alloy slab to obtain zinc alloy sheet.

2. The method for preparing a high-strength and high-toughness high-aluminum-zinc alloy plate according to claim 1, characterized in that, In step S1, the zinc alloy ingot is smelted using a covering agent protection method. The alloying elements are added in the form of pure zinc, pure aluminum, pure copper, pure magnesium, and copper-titanium master alloy. The smelting temperature is 500℃-700℃, and the casting temperature is 430℃-470℃.

3. The method for preparing a high-strength and high-toughness high-aluminum-zinc alloy plate according to claim 1, characterized in that, In step S1, the zinc alloy ingot is a square casting, which is cut into several zinc alloy sheets, and the surface of the zinc alloy sheets is ground using a grinding machine to obtain a zinc alloy raw material plate with a thickness of 4mm-8mm.

4. The method for preparing a high-strength and high-toughness high-aluminum-zinc alloy plate according to claim 1, characterized in that, In step S3, the rolling process of the zinc alloy slab includes the following steps: S31. Preheating: The zinc alloy raw material plate is preheated before hot rolling at a temperature of 240℃-320℃ for 0.5h-2h. S32, Hot Rolled: The rolling deformation in a single pass is 20%-40%, and the total deformation in hot rolling is 70%-90%; S33, Cold rolling: The deformation amount of a single pass is 20% to 50%, and the total deformation amount of cold rolling is 60% to 80%.

5. The method for preparing a high-strength and high-toughness high-aluminum-zinc alloy plate according to claim 1, characterized in that, In step S4, when the zinc alloy slab is annealed in the annealing furnace, the annealing temperature is 120℃~180℃ and the annealing time is 0.5~3h.

6. The method for preparing a high-strength and high-toughness high-aluminum-zinc alloy plate according to claim 5, characterized in that, In step S4, the zinc alloy slab is cooled to room temperature by furnace cooling or air cooling.

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