A process for producing a gradient structured aluminum alloy material
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- KUNMING UNIV OF SCI & TECH
- Filing Date
- 2024-01-15
- Publication Date
- 2026-07-10
Smart Images
Figure CN117904558B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of aluminum alloy material preparation technology, and in particular to a process for preparing gradient structure aluminum alloy materials. Background Technology
[0002] 5-series aluminum alloys are non-heat-treatable deformable aluminum alloys, and their strengthening methods are mainly solid solution strengthening and work hardening. Current research focuses on improving the properties of aluminum alloys through severe plastic deformation, with key processes including cold rolling (CR), equal channel angular deformation (ECAP), high-pressure torsion (HPT), and cumulative roll forming (ARB). These processes significantly improve the strength of aluminum alloys; however, as is known from the mechanical properties of metallic materials, strength and toughness are mutually restrictive. Therefore, aluminum alloys treated with these processes also experience a significant reduction in toughness. Controlling this mutually restrictive relationship between strength and toughness to prepare aluminum alloys with excellent overall mechanical properties will be of great significance.
[0003] During the deformation process of metallic materials, a large number of dislocations are generated as the deformation increases. These dislocations interact to form various microstructures. Based on this phenomenon, researchers have proposed a surface plastic deformation process, which allows the material surface to undergo large plastic deformation under external force, while the core remains unchanged. Through surface plastic deformation, the grains on the surface are refined, while the core grains retain their original grain size. Processes for preparing gradient structure materials include surface mechanical rolling (SMGT), surface shot peening (SMAT), ultrasonic surface rolling (USRP), and sliding friction treatment (SFT). These processes significantly improve the overall properties of metallic materials. Currently, constructing gradient structure materials to improve their overall mechanical properties remains a promising research area. Summary of the Invention
[0004] To address the problems existing in the background technology, a process for preparing gradient structure aluminum alloy materials is proposed.
[0005] This invention proposes a process for preparing gradient structure aluminum alloy materials, using hardened 5-series aluminum alloys as raw materials, characterized by the following preparation steps:
[0006] S1. The raw aluminum alloy is subjected to a "softening" annealing treatment and then air-cooled to room temperature;
[0007] S2. The softened aluminum alloy material is subjected to constrained deformation to construct a gradient structure;
[0008] S3. The material subjected to constraint deformation treatment is subjected to stabilization annealing treatment.
[0009] Preferably, the softening annealing temperature in S1 is 200°C, the annealing time is 1-2 hours, and then it is air-cooled to room temperature.
[0010] Preferably, the gradient structure constructed in S2 is a single-layer gradient structure, with one side undergoing constrained deformation to form a constrained deformation layer, and the other side undergoing free deformation to form a free deformation layer; the volume fraction ratio of the aluminum alloy constrained deformation layer to the free deformation layer is 1:1.
[0011] Preferably, the gradient structure constructed in S2 is a double-layer gradient structure. By freely deforming the surface of the material and constraining the core, a "sandwich" shaped deformation structure is obtained, which constitutes a free deformation layer and a constrained deformation layer. The volume fraction ratio of the aluminum alloy material constrained deformation layer to the free deformation layer is 1:1.
[0012] Preferably, the deformation of the free-deformable layer should be greater than 70%.
[0013] Preferably, the stabilization annealing temperature in S3 is 170℃-190℃, the stabilization annealing time is 4h, and the temperature is cooled to room temperature by air.
[0014] Preferably, the final aluminum alloy material has a gradient grain structure from long and thin to short and wide grains from the free deformation layer to the constrained deformation layer.
[0015] Compared with the prior art, the present invention has the following beneficial technical effects:
[0016] I. The present invention constructs a grain gradient structure from slender grains to wide and short grains in the grain size and shape of the constrained deformation layer to the free deformation layer. This gradient structure material will generate coordinated deformation during plastic deformation. This coordinated deformation provides the conditions for the synergistic strengthening behavior of the gradient structure material under plastic strain. The synergistic strengthening behavior activates abnormal dislocation activity and dominates the state, distribution and allocation of internal stress and plastic strain. This synergistic strengthening can significantly improve strength while maintaining or even improving ductility. Therefore, the aluminum alloy gradient structure material prepared by the present invention has comprehensive mechanical properties of high strength and high toughness.
[0017] Second, the process of this invention is simple, efficient, and low-cost, and does not have high requirements for processing conditions.
[0018] Third, this invention can prepare materials with different gradient structures. Depending on the application field of the metal material, single-layer gradient structure or double-layer gradient structure material can be constructed. By controlling the degree of constraint deformation of the material, materials with different properties can be obtained. Attached Figure Description
[0019] Figure 1 This is a schematic diagram of the aluminum alloy single-layer gradient structure material obtained by constrained deformation according to the present invention.
[0020] Figure 2This is a schematic diagram of the aluminum alloy double-layer gradient structure material obtained by constrained deformation according to the present invention.
[0021] Figure 3 This is an OM microstructure diagram of the aluminum alloy gradient structure material prepared in this invention.
[0022] Figure 4 This is a SEM microstructure image of the aluminum alloy gradient structure material prepared according to the present invention.
[0023] Figure 5 This is a stress-strain curve diagram of an embodiment of the present invention.
[0024] Figure 6 This is a comparative stress-strain curve diagram of the present invention. Detailed Implementation
[0025] This invention uses hardened 5-series aluminum alloy as raw material, such as 5083 aluminum alloy. The percentage content of each component in the raw material is as follows: 4.51% Mg, 0.54% Mn, 0.30% Fe, 0.02% Cu, 0.08% Si, 0.05% Zn, 0.07% Cr, 0.03% Ti, and the balance is Al.
[0026] Example 1
[0027] This invention proposes a process for preparing gradient structure aluminum alloy materials, the preparation process of which is as follows;
[0028] S1. The processed aluminum alloy material is solution treated at 200℃ for 2 hours, and then water quenched.
[0029] S2. The material treated in S1 undergoes constrained deformation treatment. By freely deforming the surface of the material and constraining the core, a "sandwich" shaped deformation structure is obtained, forming a free deformation layer and a constrained deformation layer. The volume fraction ratio of the constrained deformation layer to the free deformation layer of the aluminum alloy material is 1:1, causing the aluminum alloy material to form a structure like... Figure 2 The deformation gradient structure has a surface deformation of 78%, and the resulting gradient structure aluminum alloy material is a double-layer gradient structure.
[0030] S3. Anneal the constrained deformation material obtained in S2 at 170°C for 4 hours, and then air-cool it to room temperature.
[0031] The gradient structure aluminum alloy obtained in the above steps was subjected to a room temperature uniaxial tensile test at a tensile speed of 1 mm / min. During the test, the change in gauge length was measured using a contact extensometer. The measured room temperature tensile strength of the 5083 aluminum alloy was 383.6 MPa, and the elongation was 14.4%. (Stress-strain parameters are not specified in the original text.) Figure 5 .
[0032] Example 2
[0033] This invention proposes a process for preparing gradient structure aluminum alloy materials, the preparation process of which is as follows;
[0034] S1. The processed aluminum alloy material is solution treated at 200℃ for 2 hours, and then water quenched.
[0035] S2. The material processed in step S1 is subjected to constrained deformation treatment. By freely deforming the surface of the material and constraining the core, a "sandwich" shaped deformation structure is obtained, forming a free deformation layer and a constrained deformation layer. The volume fraction ratio of the constrained deformation layer to the free deformation layer of the aluminum alloy material is 1:1, so that the aluminum alloy material forms a structure like... Figure 2 The deformation gradient structure has a surface deformation of 78%, and the resulting gradient structure aluminum alloy material is a double-layer gradient structure.
[0036] S3. Anneal the constrained deformation material obtained in step S2 at 150°C for 4 hours, and then air-cool it to room temperature.
[0037] The gradient structure aluminum alloy obtained in the above steps was subjected to a room temperature uniaxial tensile test at a tensile speed of 1 mm / min. During the test, the change in gauge length was measured using a contact extensometer. The measured room temperature tensile strength of the 5083 aluminum alloy was 381.8 MPa, and the elongation was 13.6%. Figure 6 Curve 4 in the figure, such as stress-strain Figure 5 .
[0038] Example 3
[0039] This invention proposes a process for preparing gradient structure aluminum alloy materials, the preparation process of which is as follows;
[0040] S1. Anneal the processed aluminum alloy material at 200℃ for 1 hour, and then air cool it to room temperature.
[0041] S2. The material treated in S1 is subjected to constrained deformation treatment. One side is constrained to form a constrained deformation layer, and the other side is freely deformed to form a free deformation layer. The volume ratio of the constrained deformation layer to the free deformation layer of the aluminum alloy material is 1:1, so that the aluminum alloy material forms as shown in the figure. Figure 1 The deformation gradient structure has a deformation amount of 70%, and the resulting gradient structure aluminum alloy material is a single-layer gradient structure.
[0042] S3. Anneal the constrained deformation material obtained in S2 at 170°C for 4 hours, and then air-cool it to room temperature.
[0043] The gradient structure aluminum alloy obtained in the above steps was subjected to a room temperature uniaxial tensile test at a tensile speed of 1 mm / min. During the test, the change in gauge length was measured using a contact extensometer. The measured room temperature tensile strength of the 5083 aluminum alloy was 359.2 MPa, and the elongation was 10.6%. Figure 6 Curve 5, such as stress-strain Figure 5 .
[0044] Example 4
[0045] This invention proposes a process for preparing gradient structure aluminum alloy materials, the preparation process of which is as follows;
[0046] S1. Anneal the processed aluminum alloy material at 200℃ for 1 hour, and then air cool it to room temperature.
[0047] S2. The material treated in S1 undergoes constrained deformation treatment. By freely deforming the surface of the material and constraining the core, a "sandwich" shaped deformation structure is obtained, forming a free deformation layer and a constrained deformation layer. The volume fraction ratio of the constrained deformation layer to the free deformation layer of the aluminum alloy material is 1:1, causing the aluminum alloy material to form a structure like... Figure 2 The deformation gradient structure has a deformation amount of 70% for each free deformation layer, and the resulting gradient structure aluminum alloy material is a double-layer gradient structure.
[0048] S3. Anneal the constrained deformation material obtained in step S2 at 170°C for 4 hours, and then air-cool it to room temperature.
[0049] The gradient structure aluminum alloy obtained in the above steps was subjected to a room temperature uniaxial tensile test at a tensile speed of 1 mm / min. During the test, the change in gauge length was measured using a contact extensometer. The measured room temperature tensile strength of the 5083 aluminum alloy was 363.2 MPa, and the elongation was 18.7%. Figure 6 Curve 2 in the figure, such as stress-strain Figure 5 .
[0050] Example 5
[0051] This invention proposes a process for preparing gradient structure aluminum alloy materials, the preparation process of which is as follows;
[0052] S1. Anneal the processed aluminum alloy material at 200℃ for 1 hour, and then air cool it to room temperature.
[0053] S2. The material processed in step S1 is subjected to constrained deformation treatment. By freely deforming the surface of the material and constraining the core, a "sandwich" shaped deformation structure is obtained, forming a free deformation layer and a constrained deformation layer. The volume fraction ratio of the constrained deformation layer to the free deformation layer of the aluminum alloy material is 1:1, so that the aluminum alloy material forms a structure like... Figure 2 The deformation gradient structure has a surface deformation of 70%, and the resulting gradient structure aluminum alloy material is a double-layer gradient structure.
[0054] S3. Anneal the constrained deformation material obtained in step S2 at 190°C for 4 hours, and then air-cool it to room temperature.
[0055] The gradient structure aluminum alloy obtained in the above steps was subjected to a room temperature uniaxial tensile test at a tensile test speed of 1 mm / min. During the test, the change in length of the material gauge length was measured using a contact extensometer. The room temperature tensile strength of the 5083 aluminum alloy was measured to be 365.4 MPa, and the elongation was 19.0%.
[0056] Comparative Example 1
[0057] S1. Anneal the processed aluminum alloy material at 200℃ for 1 hour, and then air cool it to room temperature to obtain a "softened" sample.
[0058] S2. The material treated in S1 is subjected to unconstrained deformation treatment, so that the aluminum alloy material as a whole undergoes 70% deformation.
[0059] S3. Anneal the integral deformed material obtained in S2 at 170°C for 4 hours, and then air-cool it to room temperature.
[0060] The gradient structure aluminum alloy obtained in the above steps was subjected to a room temperature uniaxial tensile test at a tensile speed of 1 mm / min. During the test, the change in gauge length was measured using a contact extensometer. The measured room temperature tensile strength of the 5083 aluminum alloy was 411.3 MPa, and the elongation was 8.5%. (Stress-strain parameters are not specified in the original text.) Figure 6 Therefore, while large plastic deformation of the material as a whole can greatly improve its strength, it will also significantly reduce the elongation of the material.
[0061] Comparative Example 2
[0062] S1. The ingot is subjected to a two-stage homogenization treatment of 420℃×4h+510℃×10h, and then air-cooled to room temperature.
[0063] S2. The material homogenized in S1 is held at 500℃ for 2 hours and then rolled with a deformation of 90%.
[0064] S3. The hot-rolled material from S2 is cold-rolled with a deformation of 40%.
[0065] S4. The S3 cold-rolled material is subjected to stabilization annealing at 250°C for 30 minutes and then air-cooled to room temperature.
[0066] S5. Pre-stretch S4 by a deformation amount of 5%.
[0067] The gradient structure aluminum alloy obtained in the above steps was subjected to a room temperature uniaxial tensile test at a tensile speed of 1 mm / min. During the test, the change in gauge length was measured using a contact extensometer. The measured room temperature tensile strength of the 5083 aluminum alloy was 313.0 MPa, the yield strength was 178.2 MPa, and the elongation was 19.3%. (Stress-strain parameters are not specified in the original text.) Figure 6 Therefore, when aluminum alloy materials undergo small plastic deformation, the plasticity of the material is relatively large, but the yield strength and tensile strength are relatively low.
[0068] Experimental Analysis:
[0069] In addition to the above Figure 1 , 2 In addition to 5 and 6, the present invention also provides Figure 3 , Figure 4 See Table 1. Figure 3 The OM microstructure diagram of the aluminum alloy gradient structure material prepared in this invention is shown in (a), which is the free deformation part of the aluminum alloy material, with slender and densely arranged grains; (b), which is the constrained deformation part of the aluminum alloy material, with wide and short grains and sparsely arranged grains; and (c), which is another part of the free deformation of the aluminum alloy material, with slender and densely arranged grains. Figure 4 The SEM images of the aluminum alloy gradient structure material prepared in this invention are shown in (a), which shows the free deformation part of the aluminum alloy material, where the grains are slender and densely arranged, and (b), which shows the constrained deformation part of the aluminum alloy material, where the grains are wide and short and sparsely arranged. The results are consistent with the OM structure microstructure.
[0070] Tensile strength / MPa Yield strength / MPa Uniform elongation / % Example 1 383.6 300.2 14.4 Example 2 359.2 276.5 10.6 Example 3 381.8 297.4 13.6 Example 4 363.2 266.4 18.7 Example 5 365.4 270.6 19.0 Comparative Example 1 411.3 368.3 8.5 Comparative Example 2 313.0 178.2 19.3
[0071] Table 1: Statistical data on mechanical properties of examples and comparative examples
[0072] Combination Figure 1-6 As shown in Table 1, the aluminum alloy gradient structure material prepared by this invention exhibits a grain gradient structure from slender grains to wide and short grains in terms of grain size and shape from the constrained deformation layer to the free deformation layer. This gradient structure material will generate coordinated deformation during plastic deformation. This coordinated deformation provides conditions for the synergistic strengthening behavior of the gradient structure material under plastic strain. The synergistic strengthening behavior activates abnormal dislocation activity, which dominates the state, distribution and allocation of internal stress and plastic strain. This synergistic strengthening can significantly improve strength while maintaining or even achieving better ductility. Therefore, the aluminum alloy gradient structure material prepared by this invention has comprehensive mechanical properties of high strength and high toughness.
[0073] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited thereto. Various changes can be made within the scope of knowledge possessed by those skilled in the art without departing from the spirit of the present invention.
Claims
1. A process for preparing gradient structure aluminum alloy materials, using hardened 5-series aluminum alloys as raw materials, characterized in that, The preparation steps include: S1. The raw aluminum alloy is subjected to a "softening" annealing treatment and then air-cooled to room temperature; S2. The softened aluminum alloy material is subjected to constrained deformation to construct a gradient structure; S3. Stabilize and anneal the material that has undergone constrained deformation treatment. In S1, the "softening" annealing temperature is 200℃, the annealing time is 1h-2h, and then it is air-cooled to room temperature; The gradient structure constructed in S2 is a single-layer gradient structure, with one side undergoing constrained deformation to form a constrained deformation layer and the other side undergoing free deformation to form a free deformation layer. Alternatively, the gradient structure constructed in S2 is a double-layer gradient structure, where the surface of the material undergoes free deformation and the core undergoes constrained deformation to obtain a "sandwich" shaped deformation structure, forming a free deformation layer and a constrained deformation layer. The volume fraction ratio of the constrained deformation layer to the free deformation layer in the aforementioned aluminum alloy material is 1:1; The stabilization annealing temperature in S3 is 170℃-190℃, the stabilization annealing time is 4h, and it is air-cooled to room temperature.
2. The process for preparing gradient structure aluminum alloy materials according to claim 1, characterized in that, The deformation of the free deformation layer is greater than 70%.
3. The process for preparing gradient structure aluminum alloy materials according to claim 2, characterized in that, The final aluminum alloy material has a gradient grain structure from thin and long to wide and short grains from the free deformation layer to the constrained deformation layer.