Magnesium alloy molded article and molding device thereof

Abstract

A magnesium alloy molded article and a molding device thereof are provided, the device comprising: a support unit for rotatably supporting a workpiece; at least one heater module removably arranged on the outer peripheral surface of the workpiece for heating the workpiece; a rotation unit facing the support unit for rotating the workpiece supported by the support unit; and at least one roller unit for applying pressure to the workpiece while being moved in the axial direction of the workpiece and rotated along the outer peripheral surface of the workpiece.

Description

[Technical field]

[0001] The present disclosure relates to magnesium alloy shaped articles and shaping devices thereof. [Background technology]

[0002] Magnesium alloys are lightweight metals with low density among available structural materials, and are attracting attention due to their excellent characteristics such as high specific strength, machinability, and vibration absorption. Magnesium alloys can also be used for special purposes by adjusting the alloy ratio according to each application field, and research into the use of magnesium alloys in various fields is being actively conducted.

[0003] However, magnesium alloys have relatively poor mechanical properties, and therefore many efforts have been made to improve the strength and ductility of magnesium alloy workpieces through various methods. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Korean Patent Publication No. 2002-0040562 (published on May 30, 2002) Summary of the Invention [Problem to be solved by the invention]

[0005] An object of the present disclosure is to provide magnesium alloy shaped articles and shaping devices thereof. [Means for solving the problem]

[0006] According to one embodiment of the present disclosure, there is provided a magnesium alloy forming device comprising: a support unit that rotatably supports a workpiece; at least one heater module that is removably arranged on an outer peripheral surface of the workpiece and heats the workpiece; a rotation unit that faces the support unit and rotates the workpiece supported by the support unit; and at least one roller unit that applies pressure to the workpiece while being moved in the axial direction of the workpiece and rotated along the outer peripheral surface of the workpiece.

[0007] The roller unit can have a predetermined inclination with respect to the workpiece.

[0008] The roller unit may further include a roller movement unit that is moved forward or backward in the axial direction of the workpiece.

[0009] The roller unit may further include a roller rotating unit that rotates the roller unit along the outer circumferential surface of the workpiece.

[0010] The device may further include a compensation unit that is inserted into the workpiece and compensates for vibrations of the workpiece.

[0011] The device may further include a heater for heating the workpiece to a predetermined temperature.

[0012] According to one embodiment of the present disclosure, there is provided a magnesium alloy molded article obtained by molding a workpiece heated to a predetermined temperature by a magnesium alloy molding device, the magnesium alloy molding device comprising: a support unit that rotatably supports the workpiece, at least one heater module that is removably arranged on the outer peripheral surface of the workpiece and heats the workpiece, a rotation unit that faces the support unit and rotates the workpiece supported by the support unit, and at least one roller unit that applies pressure to the workpiece while being moved in the axial direction of the workpiece and rotated along the outer peripheral surface of the workpiece.

[0013] The predetermined temperature may be between 200°C and 450°C.

[0014] The rotation speed of the rotating unit can be from 300 revolutions per minute (RPM) to 1200 revolutions per minute (RPM).

[0015] The movement speed of the roller unit can be set to between 2 mm / s and 14 mm / s in the axial direction of the workpiece.

[0016] The amount of diametrical deformation of the workpiece may be between 0.05 mm and 1.5 mm. Effect of the Invention

[0017] As described above, according to the present disclosure, a magnesium alloy forming device for forming a magnesium alloy can be provided.

[0018] According to one embodiment of the present disclosure, it is possible to provide a highly reliable magnesium alloy molded article that has mechanical properties that enable it to replace aluminum materials. [Brief description of the drawings]

[0019] [Figure 1] 1 is a schematic diagram of a magnesium alloy molding device according to an embodiment of the present disclosure. FIG. [Diagram 2] FIG. 1 is a schematic cross-sectional view of a magnesium alloy forming device according to an embodiment of the present disclosure. [Diagram 3] 1 shows a cross section of an extruded magnesium alloy. [Figure 4] 1 shows a cross-section of a magnesium alloy formed article obtained by cold forming an extruded magnesium alloy. [Diagram 5] 1 shows a cross section of a magnesium alloy formed article obtained by hot forming an extruded magnesium alloy. [Figure 6]FIG. 1 is a perspective view of a magnesium alloy formed article formed by a magnesium alloy forming device according to one embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Magnesium alloy shaped articles and shaping devices thereof according to embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings.

[0021] In addition, when the components in the accompanying drawings are designated by reference numbers, the same components are designated by the same reference numbers even if the components are shown in different drawings. In addition, detailed descriptions of well-known features or functions are omitted so as not to hinder understanding of an embodiment of the present disclosure.

[0022] Terms such as "first", "second", A, B, (a), (b) and the like may be used to describe components in the embodiments of the present disclosure. These terms are used only to distinguish one component from another, and the features, order, and the like of corresponding components are not limited to these terms. In addition, unless otherwise specified, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by those skilled in the art to which the present disclosure belongs. Terms defined by commonly used dictionaries should be interpreted to have the same meaning as their meaning within the context of the relevant art, and these terms should not be interpreted ideally or excessively formally unless the context clearly dictates otherwise.

[0023] Fig. 1 is a schematic diagram of a magnesium alloy forming device according to an embodiment of the present disclosure, Fig. 2 is a schematic cross-sectional view of the magnesium alloy forming device according to an embodiment of the present disclosure, Fig. 3 shows a cross-section of an extruded magnesium alloy, Fig. 4 shows a cross-section of a magnesium alloy formed article obtained by cold forming the extruded magnesium alloy, Fig. 5 shows a cross-section of a magnesium alloy formed article obtained by hot forming the extruded magnesium alloy, and Fig. 6 is a perspective view of a magnesium alloy formed article formed by the magnesium alloy forming device according to an embodiment of the present disclosure.

[0024] 1 to 6, the magnesium alloy molding device 100 may include a support unit 110 for rotatably supporting the workpiece 10, a rotation unit 120 facing the support unit and rotating the workpiece 10 rotatably supported by the support unit 110, at least one heater module 140 removably disposed on the outer circumferential surface of the workpiece 10 for heating the workpiece 10, and at least one roller unit 130 for applying pressure to the workpiece 10 while being moved in the axial direction of the workpiece 10 and rotated along the outer circumferential surface of the workpiece 10, and the roller unit 130 is rotated with a predetermined inclination relative to the workpiece 10. The roller unit 130 may have a molding length of 1,000 mm. The workpiece 10 may be a magnesium pipe formed by extrusion molding a magnesium billet.

[0025] The workpiece 10 can be supported by the support unit 110 and rotated by the rotation unit 120. The workpiece 10 can have one surface coupled to the rotation unit 120 and the other surface supported by the support unit 110, and the workpiece 10 coupled to the rotation unit 120 can be rotated by the rotation of the rotation unit 120. The support unit 110 can be configured to provide pressure to resist vertical expansion of the workpiece 10 while the processing region of the workpiece 10 is processed by the roller unit 130. The workpiece 10 can be plastically deformed during processing, thereby elongating in length, and the support unit 110 can provide pressure to resist vertical expansion of the workpiece 10. The workpieces 10 can have different physical properties, such as different elongation and hardness, and therefore can have different amounts of elongation during processing. Here, the support unit 110 can provide pressure to resist vertical expansion of the workpiece 10 during processing, thereby enabling the workpiece 10 to maintain a constant length during processing, and thereby have an unchanged length after molding.

[0026] The roller unit 130 can shape the workpiece 10 by applying pressure to the workpiece 10 while rotating along the outer circumferential surface of the workpiece 10. The roller unit 130 can apply pressure to the workpiece 10 by moving in the axial direction of the workpiece 10 while rotating along the outer circumferential surface of the workpiece 10 and changing the forming amount that determines the cross-sectional area of ​​the workpiece 10 based on the user's selection. The roller unit 130 can move in the axial direction of the workpiece 10 and can thus form magnesium alloy molded articles of various shapes, such as a tapered shape or a wave shape. The diameter of the roller unit 130 can have a predetermined length, and can be preferably 20 mm to 300 mm.

[0027] The roller unit 130 can be tilted at a predetermined angle, and the workpiece 10 can have various shapes based on the tilt. The tilt angle can be determined based on the selection of a person skilled in the art.

[0028] The rotation unit 120 may include a rotation drive shaft for rotating the rotation unit, and the rotation drive shaft may be rotated by a drive motor. For example, the drive motor may be, but is not limited to, a stepping motor.

[0029] The roller unit 130 is an element that applies pressure to a processing area of ​​the workpiece 10 for processing, and can be fixed to, for example, a tool holder (not shown). The roller unit 130 can be rotatable in the magnesium alloy forming device 100, and can therefore be rotated by frictional force when applying pressure to the workpiece 10 for processing the workpiece. The magnesium alloy forming device 100 can be configured to be moved in the axial direction (horizontal direction in FIG. 1) and radial direction (vertical direction in FIG. 1) of the workpiece 10 for processing.

[0030] The roller unit 130 may be a roller that is in direct contact with the workpiece 10 to deform the workpiece 10. A plurality of roller units 130 may be provided, and each may be disposed above and below the workpiece 10 based on its height. The roller moving unit may be moved forward or backward relative to the support unit 110 in the horizontal direction. An adjustment link (not shown) may be linked to the movement of the roller moving unit to move the roller unit 130 toward or away from the central axis of the workpiece 10, thereby adjusting the position of the roller unit 130. The roller moving unit may be configured to move the roller unit 130 forward in the horizontal direction of the workpiece 10, or conversely, to move the roller unit 130 backward. For this purpose, the roller moving unit may be, but is not limited to, a cylinder or a servo motor arranged in the horizontal direction.

[0031] The roller unit 130 may further include a roller rotation unit (not shown) that rotates the roller unit along the outer circumferential surface of the workpiece 10 .

[0032] As the rotation unit 120 rotates, the workpiece 10 can be rotated around its vertical axis, and the roller unit 130 presses against the outer surface of the rotating workpiece 10, thus machining the machining area of ​​the workpiece 10 into the desired tapered shape.

[0033] The support unit 110 or the rotation unit 120 may further include a compensation unit (not shown) for compensating for vibrations of the workpiece 10 that occur when the workpiece 10 is rotated or processed. The compensation unit may preferably be a mandrel. The compensation unit is inserted into the workpiece 10 to compensate for vibrations caused by the rotation or processing of the workpiece 10, thus reducing forming errors caused by the vibrations and thereby improving forming reliability.

[0034] The magnesium alloy forming device may further include a heater module 140 for heating the workpiece 10 to a predetermined temperature. At least one heater module 140 may be disposed along the outer circumferential surface of the workpiece 10 while having a form of a removable cover, and a heater module 140 attached to a position requiring heating among the plurality of heater modules 140 may be selectively driven based on the forming direction or the forming position. The magnesium alloy forming device may overcome the limitation of the forming direction by including the heater module 140. The magnesium alloy forming device may perform its forward, backward, or reciprocating movement based on the type of forming direction. Also, the magnesium alloy forming device may perform a reciprocating stroke, and thus may have improved performance and productivity compared to its single stroke. The magnesium alloy forming device may heat the workpiece to a predetermined temperature by including the heater module 140, and the predetermined temperature may be 100°C to 500°C, preferably 200°C to 450°C. In the following, the heater module 140 can heat the workpiece at 200°C to 450°C, because magnesium alloys have low ductility, and therefore their workability and formability decrease at temperatures below 100°C, and at certain higher temperatures, the properties of the magnesium alloy itself may change and it may become more susceptible to internal defects. Also, the magnesium alloy forming device can use temperature controllers and actuators to improve its processing-based operation, ease of use of the equipment, and small-lot production of a variety of products.

[0035] The magnesium alloy shaped article may be formed by extruding a magnesium alloy billet to form a pipe having a predetermined strength, heat treating the extruded magnesium alloy, forming the heat treated magnesium alloy at a predetermined temperature using a magnesium alloy forming device, coating the formed magnesium alloy shaped article, and painting the coated magnesium alloy shaped article.

[0036] Extrusion The method of manufacturing a magnesium alloy shaped article may include extruding a magnesium alloy billet. The magnesium alloy billet may be extruded into a pipe shape having a predetermined strength, and the extruded magnesium alloy pipe may preferably have a strength of 350 megapascals (MPa). Extrusion is a process used to provide an object with a constant cross-sectional profile, and the extrusion process may also increase material strength. The extruded magnesium alloy article may be a pipe-shaped tube, and the magnesium alloy pipe may preferably have a length of 800 mm and a diameter of 9.5 mm.

[0037] If extrusion is performed without preheating the die, clogging may occur easily, and even when the die is preheated before extrusion, it may be preferable to adjust the ram speed or perform the extrusion without delay to prevent the die from cooling too much during extrusion. If it is difficult to preheat the die or the ram speed is too low, the billet temperature continues to drop, the extrusion load increases, and clogging may occur. As the extrusion ratio increases, the microstructure becomes finer, which ensures an increase in its strength, but may be inversely proportional to the elongation of the material. If the extrusion ratio is too low, the material may have too low strength or may be produced unevenly due to differences in the microstructure of the magnesium alloy extrusion material in each part and many coarse particles.

[0038] Magnesium alloys may include, but are not limited to, aluminum-zinc (AZ) based alloys having Al and Zn as the main additive elements, aluminum-manganese (AM) based alloys having Al and Mn as the main additive elements, zirconium-zinc (ZK) based alloys having Zr and Zn as the main additive elements, aluminum-rare earth (AE) based alloys having Al and rare earth as the main additive elements, yttrium-rare earth (WE) based alloys having Y and rare earth as the main additive elements, or alloys having Li (lithium) as the main additive element.

[0039] Heat Treatment The extruded magnesium alloy pipe can be obtained by heat treatment. In the extrusion, the extruded magnesium alloy pipe can be heat treated, and the magnesium alloy pipe can increase its tensile strength by heat treatment. The increase in tensile strength may be preferably about 10%.

[0040] molding The method may include forming the heat treated magnesium alloy. To form the magnesium alloy pipe, the magnesium alloy may be formed only within a predetermined temperature range. The predetermined temperature may preferably be 200°C to 450°C. The forming process suitable for the magnesium alloy formed article of the present disclosure may be achieved by a predetermined revolutions per minute (RPM), a predetermined feed rate, and a predetermined forming amount. The feed rate refers to the moving speed of the roller unit in the axial direction of the workpiece, and the forming amount refers to the forming amount based on the diameter of the workpiece. Preferably, the predetermined RPM may be 300RPM to 1200RPM, the predetermined feed rate may be 2mm / s to 10mm / s, and the predetermined forming amount may be, but is not limited to, 0.02mm to 10mm.

[0041] For example, the rotation speed of the rotating unit may be, but is not limited to, 300 RPM to 1200 RPM. The roller unit 130 may be moved forward or backward in the axial direction of the magnesium pipe, and may apply pressure to the magnesium pipe while rotating along the outer circumferential surface of the magnesium pipe, thereby shaping the magnesium pipe. The roller unit 130 may apply pressure to the workpiece 10 while changing the shaping amount that determines the cross-sectional area of ​​the workpiece 10 based on a user's selection.

[0042] Coatings and Paints The magnesium alloy shaped article formed in the molding can be coated in the coating and painting, and the magnesium alloy shaped article can be obtained by being coated and then painted. EXAMPLES

[0043] The magnesium alloy material is heat-treated to produce a magnesium alloy formed article. Fig. 4 shows a cross section of the magnesium alloy formed article in Example 1 before processing after extrusion of the magnesium alloy, Fig. 5 shows a cross section of the magnesium alloy formed article in Example 2 after the cold forming step in the magnesium alloy forming process, and Fig. 6 shows a cross section of the magnesium alloy formed article in Example 3 after the hot forming step in the magnesium alloy forming process.

[0044] Example 1 The magnesium alloy casting billet is extruded to produce a magnesium alloy extrusion material, which is then cut and processed to produce a specimen for compression testing, thereby producing the specimen shown in Figure 4.

[0045] Example 2 A magnesium alloy extrusion material is manufactured by extruding a magnesium alloy casting billet similar to that in Example 1. The magnesium alloy extrusion material is shaped and processed by performing a cold forming process on the magnesium alloy extrusion material, and then the magnesium alloy shaped article is cut and processed to prepare a specimen for a compression test, thereby manufacturing the specimen shown in FIG.

[0046] Test specimen of Example 3 A magnesium alloy extrusion material is manufactured by extruding a magnesium alloy casting billet similar to that in Example 1. Next, the magnesium alloy extrusion material is shaped and processed. Here, the shaping step is performed under a temperature condition of 150°C to 300°C during the shaping step, and then the magnesium alloy shaped article is cut and processed to prepare a specimen for a compression test, thereby producing the specimen shown in FIG. 6.

[0047] The present disclosure is not necessarily limited to the above-described embodiments, and it is clear to those skilled in the art to which the present disclosure pertains that the present disclosure can be modified and embodied in various ways within the scope equivalent to the present disclosure. Therefore, the true scope of the present disclosure is defined by the following claims.

Claims

1. A support unit that rotatably supports the object to be processed; At least one heater module removably disposed on an outer peripheral surface of the workpiece and configured to heat the workpiece; a rotation unit facing the support unit and rotating the workpiece supported by the support unit; at least one roller unit that applies pressure to the workpiece while moving in an axial direction of the workpiece and rotating along the outer circumferential surface of the workpiece; A magnesium alloy molding device comprising:

2. The device of claim 1 , wherein the roller unit has a predetermined inclination relative to the workpiece.

3. The device of claim 1 , further comprising a roller movement unit, the roller unit being moved forward or backward in the axial direction of the workpiece.

4. The device of claim 1 , wherein the roller unit further comprises a roller rotating unit that rotates the roller unit along the outer circumferential surface of the workpiece.

5. The device according to claim 1 , further comprising a compensation unit inserted into the workpiece to compensate for vibrations of the workpiece.

6. The device of claim 1 , further comprising a heater that heats the workpiece to a predetermined temperature.

7. A magnesium alloy molded article obtained by molding a workpiece heated to a predetermined temperature by a magnesium alloy molding device, the magnesium alloy molding device comprising: A support unit that rotatably supports the object to be processed; At least one heater module removably disposed on an outer peripheral surface of the workpiece and configured to heat the workpiece; a rotation unit facing the support unit and rotating the workpiece supported by the support unit; at least one roller unit that applies pressure to the workpiece while moving in an axial direction of the workpiece and rotating along the outer circumferential surface of the workpiece; 1. A magnesium alloy shaped article comprising:

8. 8. The article of claim 7, wherein the predetermined temperature is from 200°C to 450°C.

9. 8. The article of claim 7, wherein the rotational speed of the rotating unit is between 300 revolutions per minute (RPM) and 1200 revolutions per minute (RPM).

10. 8. The article of claim 7, wherein the roller unit has a movement speed of 2 mm / s to 14 mm / s in the axial direction of the workpiece.

11. 8. The article of claim 7, wherein the amount of deformation of the workpiece in the diametric direction is between 0.05 mm and 1.5 mm.

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