Preparation method for improving room-temperature strength and plasticity of magnesium alloy plate

Abstract

The invention discloses a preparation method for improving room-temperature strength and plasticity of a magnesium alloy plate, and belongs to the technical field of magnesium alloy materials. The method comprises the following steps: firstly, carrying out solution treatment on an original-state magnesium alloy plate; then performing a cross continuous hot rolling-shearing-bending deformation process on the magnesium alloy plate subjected to solution treatment: firstly, performing u passes of hot rolling-shearing-bending deformation along a rolling direction (RD) or a transverse direction (TD) on the magnesium alloy plate in a solution state; then, recrystallization annealing treatment is carried out; then performing w passes of hot rolling-shearing-bending deformation in the transverse direction (TD) or the rolling direction (RD); carrying out recrystallization annealing treatment on the magnesium alloy plate subjected to cross continuous hot rolling-shearing-bending deformation; and finally, the magnesium alloy plate subjected to recrystallization annealing treatment is subjected to aging treatment. The method provides a new thought for improving the comprehensive mechanical property of the magnesium alloy plate.

Description

Technical Field

[0001] The present invention relates to the technical field of magnesium alloy materials, and specifically, it is a preparation method for improving the room-temperature strength and plasticity of magnesium alloy sheets. Background Art

[0002] With the rapid increase in the demand for lightweight materials in the development of the national economy, wrought magnesium alloy sheets have shown important application prospects in high-end equipment fields such as aerospace and rail transit due to their low density, high specific strength and other characteristics. However, the insufficient matching of room-temperature strength and plasticity has become a bottleneck restricting their industrial application. Therefore, the industry urgently needs to develop new methods that can significantly improve the room-temperature strength and plasticity of wrought magnesium alloy sheets to further expand the application fields of magnesium alloy materials. Through cross continuous rolling-shearing-bending deformation and subsequent annealing processes, the basal texture characteristics of magnesium alloy sheets can be changed to form a non-basal texture characteristic, thereby greatly improving their room-temperature plasticity. However, while this non-basal texture exerts a plasticizing effect, it also causes a decrease in the room-temperature strength of magnesium alloy sheets. On the other hand, solution aging heat treatment processes can obtain good precipitation strengthening effects by precisely controlling the size, quantity and other characteristics of precipitates, which is an effective means to improve the room-temperature strength of magnesium alloy sheets. However, how to organically integrate this process with other processing technologies and jointly act on magnesium alloy sheets to achieve a double improvement in their room-temperature strength and plasticity remains a difficult problem facing the industry. Summary of the Invention

[0003] The present invention provides a new preparation method for magnesium alloy sheets, aiming to improve the room-temperature strength and plasticity of magnesium alloy sheets. This method ingeniously combines multiple process steps such as solution treatment, cross continuous hot rolling-shearing-bending deformation, recrystallization annealing treatment and aging treatment, and realizes a double improvement in the room-temperature strength and plasticity of magnesium alloy sheets by precisely controlling the characteristics of non-basal texture and precipitates.

[0004] Specifically, a preparation method for improving the room-temperature strength and plasticity of magnesium alloy sheets according to the present invention mainly includes the following steps:

[0005] P1: Prepare the as-received magnesium alloy sheet

[0006] Provide an unprocessed as-received magnesium alloy sheet as the experimental material.

[0007] P2: Solution treatment process

[0008] Perform solution treatment on the as-received magnesium alloy sheet, and the specific parameters are as follows:

[0009] Temperature range: 400°C to 450°C

[0010] Time range: 5 hours to 30 hours

[0011] P3: Cross continuous hot rolling-shearing-bending deformation

[0012] The plate after solution treatment is subjected to cross deformation treatment, and the steps are as follows:

[0013] The first step of deformation: u passes of hot rolling-shearing-bending along the rolling direction (RD) or transverse direction (TD) (u is the positive

[0014] Number); Plate heating temperature: 350℃ to 500℃

[0015] Intermediate annealing: Recrystallization annealing treatment is performed on the deformed plate, and the annealing temperature range is: 300℃ to 500℃;

[0016] Fire time range: 30 minutes to 300 minutes

[0017] The second step of deformation: hot rolling-shearing-bending in the transverse direction (TD) or rolling direction (RD) for w passes (w is the positive direction)

[0018] Number); Plate heating temperature: 350℃ to 500℃

[0019] P4: Recrystallization annealing treatment

[0020] The cross-deformed plate is recrystallized and annealed with the following parameters:

[0021] Temperature range: 300°C to 500°C

[0022] Time range: 30 minutes to 300 minutes Goal: Acquire non-basal texture features

[0023] P5: Aging Process

[0024] The annealed plate is subjected to aging strengthening treatment with the following parameters:

[0025] Temperature range: 170°C to 210°C

[0026] Time range: 10 hours to 100 hours

[0027] The beneficial effects of the present invention are as follows: a new approach for improving the comprehensive mechanical properties of magnesium alloy sheets is provided. Through the effective combination of solution treatment and cross-continuous hot rolling-shear-bending deformation, supplemented by recrystallization annealing treatment, non-basal texture characteristics are successfully introduced into the magnesium alloy sheet; at the same time, the precipitation phase characteristics of the magnesium alloy sheet are precisely controlled by solution treatment and aging treatment. The synergistic effect of this series of process steps not only gives full play to the effect of non-basal texture on the plasticity of magnesium alloy sheets, but also makes full use of the enhancement effect of precipitation strengthening on sheet strength, thereby achieving the synergistic improvement of room temperature strength and plasticity of magnesium alloy sheets. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 Flow chart of a preparation method for improving the room temperature strength and plasticity of magnesium alloy sheets Specific implementation manners

[0029] The present invention will be elaborated in detail below in conjunction with specific embodiments. It should be particularly noted that these embodiments are only intended to further illustrate the present invention and do not constitute any limitation to the protection scope of the present invention.

[0030] Example 1: Preparation method for improving the room temperature strength and plasticity of AZ61 deformed magnesium alloy sheets

[0031] First, for the original AZ61 deformed magnesium alloy sheet with a thickness of about 1.3 mm, a solution treatment process is carried out. The specific parameters are set as follows: solution temperature 415 °C, solution time 10 hours.

[0032] Subsequently, cross - continuous hot rolling - shearing - bending deformation is performed on the AZ61 magnesium alloy sheet after solution treatment: in the first stage, two - pass hot rolling - shearing - bending deformation of the sheet along the rolling direction (RD); in the second stage, a recrystallization annealing treatment is carried out, with an annealing temperature of 380 °C and an annealing time of 60 minutes; in the third stage, one - pass hot rolling - shearing - bending deformation of the sheet in the transverse direction (TD) is required. The sheet is heated to 450 °C and held for 2 minutes before deformation, and the reduction of the single - pass deformed sheet is about 5%.

[0033] After completing the cross - continuous hot rolling - shearing - bending deformation, secondary recrystallization annealing is carried out on the sheet, with an annealing temperature of 350 °C and an annealing time of 60 minutes.

[0034] The final process is aging treatment, and the specific parameters are: aging temperature 185 °C, aging time 20 hours.

[0035] Example 2: Preparation method for enhancing the room temperature strength and plasticity of AZ91 deformed magnesium alloy sheets

[0036] First, a solution treatment process is carried out on the original AZ91 deformed magnesium alloy sheet (with a thickness of about 1.5 mm), and the specific parameters are set as follows: the solution temperature is controlled at 410 °C, and the holding time is 12 hours.

[0037] Subsequently, cross - continuous hot rolling - shearing - bending deformation is carried out on the solution - treated AZ91 magnesium alloy sheet: in the first stage, two - pass hot rolling - shearing - bending deformation of the sheet along the rolling direction (RD); the second stage is recrystallization annealing treatment, with the annealing temperature set at 360 °C and the duration of 60 minutes; in the third stage, the sheet needs to be subjected to one - pass hot rolling - shearing - bending deformation along the rolling direction (RD), thus completing the cross - continuous hot rolling - shearing - bending deformation process. Before each deformation, the AZ91 magnesium alloy sheet needs to be heated to 430 °C and held for 3 minutes, and the reduction of the sheet during the deformation process is about 5%.

[0038] After completing the cross - continuous hot rolling - shearing - bending deformation, recrystallization annealing treatment is carried out on the AZ91 magnesium alloy sheet, with the annealing temperature adjusted to 350 °C and the holding time maintained at 60 minutes.

[0039] In the final stage, aging treatment is carried out on the recrystallization - annealed AZ91 magnesium alloy sheet, with the aging temperature set at 195 °C and the aging duration of 15 hours.

Claims

1. A preparation method for improving the room temperature strength and plasticity of magnesium alloy sheets, the specific steps are as follows: Prepare magnesium alloy sheets in the original state; perform solution treatment on the sheets; perform a cross - continuous hot rolling - shearing - bending deformation process on the solution - treated magnesium alloy sheets: First, perform hot rolling - shearing - bending deformation on the solution - state magnesium alloy sheets in u passes along the rolling direction (RD) or the transverse direction (TD); Subsequently, perform recrystallization annealing treatment; Then, perform hot rolling - shearing - bending deformation on the w passes along the transverse direction (TD) or the rolling direction (RD); Perform recrystallization annealing treatment on the magnesium alloy sheets that have completed the cross - continuous hot rolling - shearing - bending deformation; Finally, perform aging treatment on the magnesium alloy sheets after the recrystallization annealing treatment.

2. The preparation method according to claim 1, wherein: In the solution treatment, the solution temperature is set to 400°C to 450°C, and the solution time is set to 5 hours to 30 hours.

3. The preparation method according to claim 1, wherein: In the cross - continuous hot rolling - shearing - bending deformation, the heating temperature of the sheet is set to 350°C to 500°C.

4. The preparation method according to claim 1, wherein: In the recrystallization annealing treatment, the annealing temperature is set to 300°C to 500°C, and the annealing time is set to 30 minutes to 300 minutes.

5. The preparation method according to claim 1, wherein: In the aging treatment, the aging temperature is set to 170°C to 210°C, and the aging time is set to 10 hours to 100 hours.

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