Magnesium alloy sheet and preparation method for suppressing edge cracking during rolling of magnesium alloy sheet

Abstract

This disclosure provides a method for suppressing edge cracking during the rolling of magnesium alloy sheets, belonging to the field of magnesium alloy processing technology. The method includes: providing an auxiliary liner; fixing the auxiliary liner to both sides of the magnesium alloy sheet raw material to form a combined sheet; preheating and heat-insulating the combined sheet; hot-rolling the heat-insulated combined sheet; and removing the auxiliary liner. This method reduces edge cracking during the rolling of magnesium alloy sheets and lowers the rolling cost.

Description

Technical Field

[0001] This disclosure relates to the field of magnesium alloy processing technology, and more specifically, to a magnesium alloy sheet and a method for preparing a magnesium alloy sheet to suppress edge cracking during rolling. Background Technology

[0002] Magnesium and magnesium alloys are currently the lightest metallic structural materials used in engineering applications. They possess advantages such as light weight, high specific strength, excellent damping and vibration reduction performance, good electromagnetic shielding performance, and easy recyclability, making them widely used in electronics, automotive, aerospace, and many other fields. However, due to the close-packed hexagonal crystal structure of magnesium alloys, the number of independent slip systems that can be activated during low-temperature deformation is relatively small, resulting in poor room-temperature deformation capacity. This makes magnesium alloy sheets highly susceptible to severe edge cracking defects during conventional rolling processes. Edge cracking is mainly caused by excessive tensile stress due to lateral extension at the edges and the difference in flow velocity between the edges and the middle during the rolling process. Edge cracking reduces the production quality of magnesium alloy sheets and significantly limits their large-scale application. Therefore, edge cracking has become a hot topic in magnesium alloy processing, and developing technological methods to reduce or suppress edge cracking during magnesium alloy rolling is of great practical significance.

[0003] A search revealed that patent document CN114132022A discloses a wedge-shaped liner for hard and brittle high-modulus magnesium alloys, along with its edge-crack control rolling method and application. The principle involves using a wedge-shaped liner containing a grooved plate and a cover plate to assist in rolling magnesium alloy sheets. While this method can effectively reduce edge cracking during rolling, it is only suitable for hard and brittle high-modulus magnesium alloy sheets, thus having certain limitations. Furthermore, the grooved wedge-shaped liner needs to be processed separately, and the magnesium alloy sheet may be difficult to remove after being rolled and deformed within the grooves of the wedge-shaped liner, making it unsuitable for industrial applications. Patent document CN110947766A discloses a conical roll and its rolling method for reducing edge cracking of magnesium alloy sheets. The principle involves selecting a suitable conical sleeve and using a conical roll (composed of a baffle, conical sleeve, and roll body) to roll the slab in one pass, pre-forming the edge convexity of corresponding height and width. Then, ordinary rolls are used to roll the slab into a thin sheet. Alternatively, a single pass can be performed using conical rolls to pre-form the edge convexity of the slab, with intermediate passes using alternating ordinary flat rolls and conical rolls, and a final pass using ordinary flat rolls to roll the slab into a thin sheet. This method requires the use of special rolls, has high manufacturing costs, and a complex and cumbersome process, making it unsuitable for industrial application.

[0004] It should be noted that the information disclosed in the background section above is only used to enhance the understanding of the background of this disclosure, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0005] The purpose of this disclosure is to overcome the shortcomings of the prior art and provide a magnesium alloy sheet and a method for suppressing edge cracking during the rolling process of magnesium alloy sheets. This reduces edge cracking of magnesium alloy sheets during processing. Furthermore, this preparation method utilizes conventional rolling techniques to reduce edge cracking. Moreover, the surface of the magnesium alloy sheet does not require pretreatment in this preparation method, and the entire process is easy to implement and simple to operate, showing promising prospects for industrial application.

[0006] According to the first aspect of this disclosure, a method for suppressing edge cracking during the rolling of magnesium alloy sheets is provided, comprising:

[0007] Provide auxiliary lining plates;

[0008] The auxiliary liner is detachably fixed to both sides of the magnesium alloy sheet material to form a combined sheet material;

[0009] The composite panels are preheated and insulated.

[0010] The insulated composite panels are then subjected to hot rolling treatment.

[0011] Remove the auxiliary liner.

[0012] According to one embodiment of this disclosure, the auxiliary liner is made of at least one of pure magnesium, magnesium alloy, or aluminum alloy.

[0013] According to one embodiment of this disclosure, when the composite board is preheated and insulated, the preheating and insulation temperature of the composite board is between 300 and 450°C.

[0014] According to one embodiment of this disclosure, when the composite board is preheated and insulated, the preheating and insulation time of the composite board is between 10 and 30 minutes.

[0015] According to one embodiment of this disclosure, the thickness of the magnesium alloy sheet material is between 3 and 10 mm, the width of the magnesium alloy sheet material is between 50 and 200 mm, and the width of the auxiliary liner is smaller than the width of the magnesium alloy sheet material.

[0016] According to one embodiment of this disclosure, the width of the auxiliary liner is between 10 and 30 millimeters.

[0017] According to one embodiment of this disclosure, when auxiliary lining plates are detachably fixed to both sides of a magnesium alloy sheet material to form a combined sheet, the thickness of the auxiliary lining plates on both sides is the same as the thickness of the magnesium alloy sheet material, and the length of the magnesium alloy sheet material is the same as the length of the auxiliary lining plates.

[0018] According to one embodiment of this disclosure, when the preheated and heat-insulated composite plate is hot-rolled, the deformation per pass of the hot rolling process is between 15% and 65%, and the rolling speed of the hot rolling process is between 10 and 20 m / min.

[0019] According to one embodiment of this disclosure, when the auxiliary liner is detachably fixed to both sides of the magnesium alloy sheet material to form a combined sheet, the auxiliary liner is bound to both sides of the magnesium alloy sheet material by metal wire.

[0020] According to another aspect of this disclosure, a magnesium alloy sheet is provided, which is prepared by the method for suppressing edge cracking during rolling of the magnesium alloy sheet as described in the claims. Attached Figure Description

[0021] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure. It is obvious that the drawings described below are merely some embodiments of this disclosure, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0022] Figure 1 This is a schematic diagram of the preparation steps of a method for suppressing edge cracking during rolling of magnesium alloy sheet in one embodiment of this disclosure.

[0023] Figure 2 This is a schematic diagram of the macroscopic morphology of the magnesium alloy sheet after rolling in Example 1.

[0024] Figure 3 This is a schematic diagram of the macroscopic morphology of the magnesium alloy sheet after rolling in Example 2.

[0025] Figure 4 This is a schematic diagram of the macroscopic morphology of the magnesium alloy sheet after rolling, as shown in Comparative Example 1.

[0026] Figure 5 This is a schematic diagram of the macroscopic morphology of the magnesium alloy sheet after rolling, as shown in Comparative Example 2. Detailed Implementation

[0027] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, they are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the exemplary embodiments to those skilled in the art. The same reference numerals in the drawings denote the same or similar structures, and therefore detailed descriptions of them will be omitted. Furthermore, the drawings are merely illustrative of this disclosure and are not necessarily drawn to scale.

[0028] In related technologies, there are several methods for rolling magnesium alloy sheets. First, rolling magnesium alloy sheets is assisted by a wedge-shaped liner containing a grooved plate and a cover plate. This method can reduce edge cracking of magnesium alloy sheets to a certain extent, but it is only suitable for hard and brittle magnesium alloy sheets with high modulus, which has certain limitations. At the same time, the wedge-shaped liner with grooves needs to be processed separately, and the magnesium alloy sheet may be difficult to remove after being rolled and deformed in the groove of the wedge-shaped liner, which is not suitable for industrial applications. Secondly, a suitable tapered sleeve is selected, and the slab is rolled in one pass using a tapered roll consisting of a baffle, tapered sleeve, and roll body to pre-form the edge convexity of the corresponding height and width. Then, the slab is rolled into a thin plate using ordinary rolls. Alternatively, a tapered roll is used to roll in one pass to pre-form the edge convexity of the slab. The intermediate passes are rolled alternately with ordinary flat rolls and tapered rolls. The last pass is rolled into a thin plate using ordinary flat rolls. This method requires the use of special rolls, has a high manufacturing cost, and the process is complex and cumbersome, making it unsuitable for industrial applications.

[0029] Based on this, this disclosure provides a method for preparing magnesium alloy sheets to suppress edge cracking during rolling. See also... Figure 1 The preparation method includes steps S1 to S5.

[0030] Step S1: Provide auxiliary lining plates.

[0031] Step S2: The auxiliary liner is detachably fixed to both sides of the magnesium alloy sheet material to form a combined sheet.

[0032] Step S3: Preheat and insulate the composite panels.

[0033] Step S4: Perform hot rolling treatment on the preheated and heat-insulated composite plate.

[0034] Step S5: Remove the auxiliary liner.

[0035] The method for suppressing edge cracking during the rolling of magnesium alloy sheets disclosed herein involves adding auxiliary liners to both sides of the magnesium alloy sheet raw material, with the auxiliary liners and the magnesium alloy sheet raw material laterally combined to form a composite sheet. The composite sheet is hot-rolled using a conventional symmetrical rolling process. During the rolling process, the auxiliary liners on both sides of the magnesium alloy sheet raw material effectively suppress the lateral widening of the edge of the magnesium alloy sheet raw material, reducing the edge tensile stress to a certain extent and thus suppressing edge cracking. This results in magnesium alloy rolled sheets with significantly reduced edge cracking, significantly improving the yield of magnesium alloy sheets. Furthermore, the method for suppressing edge cracking during the rolling of magnesium alloy sheets disclosed herein does not require special treatment of the magnesium alloy sheet raw material (e.g., it does not require complex surface treatment processes such as grinding, cleaning, and lubrication), which helps improve the processing efficiency of magnesium alloy sheets. Moreover, the auxiliary liners are readily available, and the entire rolling process of the magnesium alloy sheet is simple and easy to operate, helping to reduce the processing cost of magnesium alloy sheets.

[0036] In some embodiments of this disclosure, the magnesium alloy sheet is made of magnesium, zinc, zirconium, and cerium.

[0037] The preparation method for suppressing edge cracking during rolling of magnesium alloy sheets provided in this disclosure will be described in detail below.

[0038] In some embodiments of this disclosure, when providing the auxiliary liner, the material of the auxiliary liner can be at least one selected from pure magnesium, magnesium alloy, or aluminum alloy sheet. For example, the material of the auxiliary liner is pure magnesium, magnesium alloy, or aluminum alloy.

[0039] In some embodiments of this disclosure, when the auxiliary liner is detachably fixed to both sides of the magnesium alloy sheet material to form a composite sheet, the auxiliary liner is bound to both sides of the magnesium alloy sheet material by metal wire. For example, the metal wire can be iron wire, copper wire, or aluminum wire. It should be noted that in other embodiments, the material of the metal wire is not limited to these.

[0040] It should be noted that, in this embodiment, the two sides of the magnesium alloy sheet material refer to the two sides in the width direction of the magnesium alloy sheet material. Furthermore, in this embodiment, the metal wires are disposed at both ends of the composite sheet, and the specific location of the metal wires is not specifically limited.

[0041] As an example, the metal wire is iron wire, and there is no specific limitation on the diameter of the iron wire, as long as it can achieve the function of detachably fixing the auxiliary liner to both sides of the magnesium alloy sheet material.

[0042] In some embodiments of this disclosure, when the auxiliary liner is detachably fixed to both sides of the magnesium alloy sheet material to form a composite sheet, the preheating and insulation temperature of the composite sheet is between 300 and 450°C. For example, the preheating and insulation temperature of the composite sheet is 300°C, 350°C, 400°C, or 450°C. It should be noted that in other embodiments of this disclosure, the preheating and insulation temperature of the composite sheet is not limited to this.

[0043] In some embodiments of this disclosure, when the auxiliary liner is detachably fixed to both sides of the magnesium alloy sheet material to form a composite sheet, the preheating and heat preservation time of the composite sheet is between 10 and 30 minutes. For example, the preheating and heat preservation time of the composite sheet is 10 minutes, 15 minutes, 25 minutes, or 30 minutes. It should be noted that in other embodiments of this disclosure, the preheating and heat preservation time of the composite sheet is not limited to this.

[0044] In some embodiments of this disclosure, the thickness of the magnesium alloy sheet material is between 3 and 10 mm. For example, the thickness of the magnesium alloy sheet material is 3 mm, 6 mm, 9 mm, or 10 mm. It should be noted that in other embodiments, the thickness of the magnesium alloy sheet material is not limited to these values.

[0045] In some embodiments of this disclosure, the width of the magnesium alloy sheet material is between 50 and 200 mm. For example, the width of the magnesium alloy sheet material is 50 mm, 100 mm, 150 mm, or 200 mm. It should be noted that in other embodiments, the width of the magnesium alloy sheet material is not limited to these dimensions.

[0046] In some embodiments of this disclosure, the width of the auxiliary liner is smaller than the width of the magnesium alloy sheet material.

[0047] As an example, the thickness of the magnesium alloy sheet material is between 3 and 10 mm, the width of the magnesium alloy sheet material is between 50 and 200 mm, and the width of the auxiliary lining plate is smaller than the width of the magnesium alloy sheet material.

[0048] In some embodiments of this disclosure, the width of the auxiliary liner is between 10 and 30 mm. For example, the width of the auxiliary liner is 10 mm, 15 mm, 20 mm, or 30 mm. It should be noted that in other embodiments, the width of the auxiliary liner is not limited to these.

[0049] In some embodiments of this disclosure, when auxiliary liners are detachably fixed to both sides of magnesium alloy sheet material to form a composite sheet, the thickness of the auxiliary liners provided on both sides of the magnesium alloy sheet material is the same as the thickness of the magnesium alloy sheet material. In this way, when the magnesium alloy sheet material is rolled, the surfaces of the magnesium alloy sheet material and the auxiliary liners can come into contact with the rolling rolls together.

[0050] In some embodiments of this disclosure, when the auxiliary liner is detachably fixed to both sides of the magnesium alloy sheet material to form a combined sheet, the length of the magnesium alloy sheet material is the same as the length of the auxiliary liner. This effectively prevents lateral expansion of the edges of the magnesium alloy sheet material.

[0051] As an example, when auxiliary lining plates are detachably fixed to both sides of magnesium alloy sheet material to form a composite sheet, the thickness of the auxiliary lining plates on both sides of the magnesium alloy sheet material is the same as the thickness of the magnesium alloy sheet material; the length of the magnesium alloy sheet material is the same as the length of the auxiliary lining plates.

[0052] In some embodiments of this disclosure, when the preheated and heat-insulated composite sheet is hot-rolled, the deformation per pass of the hot-rolling process is between 15% and 65%. For example, the deformation per pass of the hot-rolling process is 15%, 35%, 55%, or 65%. It should be noted that in other embodiments, the deformation per pass of the hot-rolling process is not limited to these values.

[0053] In some embodiments of this disclosure, when hot-rolling the preheated and heat-insulated composite sheet, the rolling speed for hot rolling is between 10 and 20 m / min. For example, the rolling speed for hot rolling is 10 m / min, 14 m / min, 18 m / min, or 20 m / min. It should be noted that in other embodiments, the rolling speed for hot rolling is not limited to these.

[0054] As an example, when the preheated and heat-insulated composite plate is hot-rolled, the deformation per pass of the hot rolling process is between 15% and 65%; the rolling speed of the hot rolling process is between 10 and 20 m / min.

[0055] This disclosure also provides a magnesium alloy sheet, which is prepared by the above-described method for suppressing edge cracking during the rolling of magnesium alloy sheets.

[0056] The following description, in conjunction with different embodiments and corresponding accompanying drawings, further illustrates the preparation method for suppressing edge cracking during rolling of magnesium alloy sheets provided by the present disclosure.

[0057] Example 1:

[0058] Example 1 describes the preparation of crack-free magnesium alloy sheets using transverse composite rolling with a set reduction of 61.6% per pass.

[0059] The specific preparation steps are as follows:

[0060] Step 1: Provide an auxiliary liner. In this embodiment, the auxiliary liner is made of magnesium alloy; the auxiliary liner has a length of 100 mm, a width of 15 mm, and a height of 5 mm.

[0061] Step 2: Detachably fix the auxiliary lining plates to both sides of the magnesium alloy sheet material to form a composite sheet. Specifically, use thin iron wire to bind the auxiliary lining plates together to obtain a horizontally stacked composite sheet.

[0062] In this step, the magnesium alloy sheet material is 100 mm long, 40 mm wide, and 5 mm thick.

[0063] Step 3: Preheat and insulate the composite panels. Specifically, place the composite panels in a heat treatment circuit for preheating and insulation treatment at a temperature of 350℃ for 30 minutes.

[0064] Step 4: Hot rolling the preheated and heat-insulated composite plate. Specifically, after preheating and heat-insulating the composite plate, a twin-roll mill is used to perform single-pass synchronous deformation rolling. In this step, the mill roll gap is set to 1.92 mm, the rolling reduction rate is 61.6%, and the rolling speed is 10 m / min.

[0065] Step 5: Remove the auxiliary liner. Specifically, after the composite sheet is rolled, the auxiliary liner is removed to obtain a magnesium alloy sheet without obvious edge cracks.

[0066] Figure 2 The schematic diagram shows a magnesium alloy sheet after rolling, indicating that the sheet has no obvious edge cracks.

[0067] Example 2:

[0068] Example 2: Crack-free magnesium alloy sheet was prepared by transverse composite rolling with a set reduction of 63.6% per pass.

[0069] The specific preparation steps are as follows:

[0070] Step 1: Provide an auxiliary liner. In this embodiment, the auxiliary liner is made of magnesium alloy; the auxiliary liner is 100 mm long, 15 mm wide, and 5 mm thick.

[0071] Step 2: Detachably fix the auxiliary lining plates to both sides of the magnesium alloy sheet material to form a composite sheet. Specifically, use thin iron wire to bind the auxiliary lining plates together to obtain a horizontally stacked composite sheet.

[0072] In this step, the magnesium alloy sheet material is 100 mm long, 40 mm wide, and 5 mm thick.

[0073] Step 3: Preheat and insulate the composite panels. Specifically, place the composite panels in a heat treatment furnace for preheating and insulation at a temperature of 350℃ for 30 minutes.

[0074] Step 4: Hot rolling the preheated and heat-insulated composite plate. Specifically, after preheating and heat-insulating the composite plate, a twin-roll mill is used to perform single-pass synchronous deformation rolling. In this step, the mill roll gap is set to 1.82 mm, the rolling reduction rate is 63.6%, and the rolling speed is 13 m / min.

[0075] Step 5: Remove the auxiliary liner. Specifically, after the composite sheet is rolled, the auxiliary liner is removed to obtain a magnesium alloy sheet without obvious edge cracks.

[0076] Figure 3 The schematic diagram shows the magnesium alloy sheet after rolling in step two, indicating that the sheet has no obvious edge cracks. To further verify the effectiveness of the preparation method for suppressing edge cracks in magnesium alloy sheets during rolling, this disclosure provides comparative examples (e.g., Comparative Example 1 and Comparative Example 2) to further verify the preparation method.

[0077] Comparative Example 1:

[0078] It should be noted that the difference between Comparative Example 1 and Example 1 is that in Comparative Example 1, auxiliary lining plates are not tied to both sides of the magnesium alloy sheet material before rolling, and Comparative Example 1 and Example 1 use the same rolling process (for example, the mill roll gap is set to 1.92 mm, the rolling reduction rate is 61.6%, and the rolling speed is 10 m / min).

[0079] Figure 4 The diagram shows the rolled magnesium alloy sheet from Comparative Example 1. It can be seen that the rolled magnesium alloy sheet contains a large number of edge cracks. Therefore, it can be verified that the proposed preparation method can significantly reduce the occurrence of edge cracks in magnesium alloy sheets.

[0080] Comparative Example 2:

[0081] It should be noted that the difference between Comparative Example 2 and Example 2 is that in Comparative Example 2, auxiliary lining plates are not tied to both sides of the magnesium alloy sheet material before rolling, and Comparative Example 2 and Example 2 use the same rolling process (for example, the mill roll gap is set to 1.82 mm, the rolling reduction rate is 63.6%, and the rolling speed is 13 m / min).

[0082] Figure 5 The diagram below shows the rolled magnesium alloy sheet from Comparative Example 2. It can be seen that the rolled magnesium alloy sheet contains a large number of edge cracks. Therefore, this further verifies that the proposed preparation method can significantly reduce the occurrence of edge cracks in magnesium alloy sheets.

[0083] Other embodiments of this disclosure will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this disclosure are indicated by the appended claims.

Claims

1. A method for preparing magnesium alloy sheets to suppress edge cracking during rolling, characterized in that, include: Provide auxiliary lining plates; The auxiliary liner is detachably fixed to both sides of the magnesium alloy sheet material, wherein the two sides of the magnesium alloy sheet material are the two sides in the width direction of the magnesium alloy sheet material, forming a combined sheet material; The composite panels are preheated and insulated. The preheated and heat-insulated composite plate is subjected to hot rolling treatment; during the rolling of the magnesium alloy plate raw material, the surfaces of the magnesium alloy plate raw material and the auxiliary liner plate are in contact with the rolling rolls together; Remove the auxiliary liner.

2. The preparation method for suppressing edge cracking during rolling of magnesium alloy sheet according to claim 1, characterized in that, The auxiliary liner is made of at least one of pure magnesium, magnesium alloy, or aluminum alloy.

3. The preparation method for suppressing edge cracking during rolling of magnesium alloy sheet according to claim 1, characterized in that, When the composite panel is preheated and insulated, the preheating and insulation temperature is between 300 and 450°C.

4. The preparation method for suppressing edge cracking during rolling of magnesium alloy sheet according to claim 1 or 3, characterized in that, When preheating and insulating the composite board, the preheating and insulation time is between 10 and 30 minutes.

5. The preparation method for suppressing edge cracking during rolling of magnesium alloy sheet according to claim 1, characterized in that, The thickness of the magnesium alloy sheet material is between 3 and 10 mm, the width of the magnesium alloy sheet material is between 50 and 200 mm, and the width of the auxiliary liner is smaller than the width of the magnesium alloy sheet material.

6. The preparation method for suppressing edge cracking during rolling of magnesium alloy sheet according to claim 1 or 5, characterized in that, The width of the auxiliary liner is between 10 and 30 mm.

7. The preparation method for suppressing edge cracking during rolling of magnesium alloy sheet according to claim 1, characterized in that, When auxiliary lining plates are detachably fixed to both sides of magnesium alloy sheet material to form a combined sheet, the thickness of the auxiliary lining plates on both sides of the magnesium alloy sheet material is the same as the thickness of the magnesium alloy sheet material, and the length of the magnesium alloy sheet material is the same as the length of the auxiliary lining plates.

8. The preparation method for suppressing edge cracking during rolling of magnesium alloy sheet according to claim 1, characterized in that, When hot rolling the preheated and heat-insulated composite plate, the deformation per pass of the hot rolling process is between 15% and 65%, and the rolling speed of the hot rolling process is between 10 and 20 m / min.

9. The preparation method for suppressing edge cracking during rolling of magnesium alloy sheet according to claim 1, characterized in that, When the auxiliary liner is detachably fixed to both sides of the magnesium alloy sheet material to form a combined sheet, the auxiliary liner is bound to both sides of the magnesium alloy sheet material by metal wire.

10. A magnesium alloy sheet, characterized in that, The magnesium alloy sheet is prepared by the method for suppressing edge cracking during rolling of magnesium alloy sheet as described in any one of claims 1 to 9.

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