Device and method for removing oxide skin in aluminum alloy extrusion process

Abstract

The invention provides a device and method for removing oxide skin in the aluminum alloy extrusion process, and the device for removing the oxide skin in the aluminum alloy extrusion process comprises an extrusion cylinder and an extrusion die; the extrusion cylinder is connected with the extrusion die, a spiral stirring structure is arranged in the extrusion cylinder or the extrusion die, the spiral stirring structure comprises a plurality of cavities, and the tail ends of the cavities in the extrusion advancing direction are subjected to closing-up treatment. The oxide skin on the aluminum alloy blank is crushed through the multiple cavities, the oxide skin is further refined through the tail ends of the cavities, and part of the refined oxide skin enters the extrusion die through the cavities to be subjected to forming operation, so that harmful oxide skin and other inclusions play a favorable strengthening role, and waste generated in the extrusion forming process is reduced; the waste of materials is reduced, and the yield is greatly improved.

Description

Technical Field

[0001] The invention relates to the technical field of aluminum alloy extrusion, and in particular to a device and process for removing oxide scale in an aluminum alloy extrusion process. Background Art

[0002] When extruding aluminum alloy, it needs to be heated to a high temperature range of 400-500℃. Due to the extremely active chemical properties of aluminum, an oxide film will quickly form on the surface of aluminum in this high temperature environment. When the front and rear billets come into contact with each other during the extrusion process, problems will arise in the transverse weld area due to the presence of inclusions such as oxide scale, causing the quality of the transverse weld of the extruded product to be significantly reduced, making it difficult to meet the requirements of high-quality production standards, and having an adverse effect on the overall performance and appearance of the product, and may cause potential safety hazards and quality defects during subsequent processing or use.

[0003] In the prior art, the method for treating the oxide film is generally to cut off the transverse weld area of ​​the extruded product as waste, which wastes a large amount of material and greatly reduces the yield rate. Summary of the invention

[0004] In view of this, the present invention proposes an apparatus and method for removing oxide scale during aluminum alloy extrusion to solve the technical problem proposed in the above background technology that the transverse weld area of ​​the extruded product is cut off as waste, wasting a large amount of material and greatly reducing the yield.

[0005] The technical solution of the present invention is achieved in this way:

[0006] In the first aspect, the present invention provides an oxide scale removal device during the aluminum alloy extrusion process, comprising an extrusion barrel and an extrusion die; the extrusion barrel is connected to the extrusion die, and a spiral stirring structure is provided in the extrusion barrel or the extrusion die, wherein the spiral stirring structure comprises a plurality of cavities, and the ends of the cavities along the extrusion forward direction are closed.

[0007] On the basis of the above technical solution, preferably, the cross-sectional area of ​​the cavity gradually decreases along the extrusion direction.

[0008] On the basis of the above technical solution, preferably, the cross-sectional area of ​​the aluminum alloy billet is S, the number of the cavities is N, the cross-sectional area of ​​the front end of the cavity is S1, S / 6N≤S1<S / N, and the cross-sectional area of ​​the end of the cavity is less than or equal to 200mm 2 .

[0009] On the basis of the above technical solution, preferably, the contour of the cavity along the extrusion forward direction is a straight line or a curve.

[0010] On the basis of the above technical solution, preferably, the cavity is formed by being separated by a plurality of diversion bridges.

[0011] On the basis of the above technical solution, preferably, the shapes and sizes of the plurality of cavities are the same.

[0012] Based on the above technical solution, preferably, the shapes and sizes of the plurality of cavities are different.

[0013] On the basis of the above technical solution, preferably, the cavity is divided into a plurality of channels in the extrusion forward direction.

[0014] On the basis of the above technical solution, preferably, a protrusion structure is provided on the inner wall of the cavity.

[0015] In a second aspect, the present invention provides a method for removing oxide scale during aluminum alloy extrusion, using the device for removing oxide scale during aluminum alloy extrusion as described in the first aspect, comprising:

[0016] Introducing the aluminum alloy billet through the extrusion barrel;

[0017] The oxide scale on the aluminum alloy billet is broken by using multiple cavities;

[0018] The oxide scale is further refined through the end of the cavity, so that the refined oxide scale is dispersedly distributed, and part of the refined oxide scale enters the extrusion die through the cavity for forming operation.

[0019] The device and method for removing oxide scale during aluminum alloy extrusion process of the present invention have the following beneficial effects compared with the prior art:

[0020] (1) A spiral stirring structure is provided in the extrusion cylinder or the extrusion die, and the spiral stirring structure includes a plurality of cavities, and the ends of the cavities along the extrusion direction are closed. The oxide scale on the aluminum alloy billet is broken through the plurality of cavities, and the oxide scale is further refined through the ends of the cavities. The refined part of the oxide scale enters the extrusion die through the cavity for forming operation, so that harmful inclusions such as oxide scale play a beneficial strengthening role, reduce the generation of waste in the extrusion forming process, reduce material waste, and greatly improve the yield rate;

[0021] (2) The cross-sectional area of ​​the cavity is gradually reduced along the extrusion direction, so that the oxide scale is gradually refined from the outer periphery to the inner circle, and the degree of refinement of the oxide scale is improved, so that more of the oxide scale is converted into beneficial raw materials, reducing material waste and improving the yield rate;

[0022] (3) The cross-sectional area of ​​the aluminum alloy billet is S, the number of cavities is N, the cross-sectional area of ​​the front end of the cavity is S1, S / 6N≤S1<S / N, and the cross-sectional area of ​​the end of the cavity is less than or equal to 200mm 2By setting this parameter, the oxide scale is initially broken into a cross-sectional area of ​​S1, and then the oxide scale in each cavity is gradually refined from the outer circle to the inner circle to less than or equal to 200mm. 2 , so that the oxide scale can be converted into beneficial raw materials as much as possible, reducing material waste;

[0023] (4) By keeping the shapes and sizes of multiple diversion bridges completely consistent, a uniform and stable diversion effect can be achieved under specific process requirements, ensuring that the flow characteristics of the material in each cavity are the same;

[0024] (5) The shapes and sizes of the plurality of diverter bridges are different to meet the complex requirements of some special processes for different flow rates and flow velocities, thereby improving the scope of application and adaptability of the device;

[0025] (6) The cavity is used to divide the flow into multiple channels in the extrusion forward direction. This multi-stage diversion design can, on the one hand, further divide and refine the billet during the extrusion flow process; on the other hand, it provides multiple channels to reduce the metal flow resistance and the required extrusion force, thereby further refining the material processing process. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0027] Figure 1 is a cross-sectional view of an oxide scale removal device in an aluminum alloy extrusion process in an embodiment of the present invention;

[0028] Figure 2 is a cross-sectional view of a spiral stirring structure of a curved cavity in an embodiment of the present invention;

[0029] Figure 3 It is a cross-sectional view of a spiral stirring structure of a curved cavity (with a flow channel for diversion) in an embodiment of the present invention;

[0030] Figure 4 is a cross-sectional view of a spiral stirring structure of a linear cavity in an embodiment of the present invention;

[0031] Figure 5 sectional views of cavities of different shapes in the spiral stirring structure in the embodiment of the present invention;

[0032] Figure 6 It is a schematic flow chart of a method for removing oxide scale during aluminum alloy extrusion in an embodiment of the present invention.

[0033] Description of reference numerals: 1-extrusion cylinder, 2-extrusion die, 3-spiral stirring structure;

[0034] 21-flow expansion hole, 22-welding chamber, 23-working belt;

[0035] 31- cavity, 32- channel, 33- protrusion structure. DETAILED DESCRIPTION

[0036] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] Reference Figure 1-5 As shown, the first embodiment of the present invention proposes an oxide scale removal device during aluminum alloy extrusion, comprising an extrusion barrel 1 and an extrusion die 2; the extrusion barrel 1 is connected to the extrusion die 2, the extrusion barrel 1 is a cylindrical structure with a hollow interior, a conical expansion hole 21 is provided in the extrusion die 2, the diameter of the small diameter end of the expansion hole 21 is smaller than the inner hole diameter of the extrusion barrel 1, a welding chamber 22 and a working belt 23 are also provided in the extrusion die 2, the welding chamber 22 is located at the end of the expansion hole 21 away from the extrusion barrel 1, the welding chamber 22 is located between the expansion hole 21 and the working belt 23, the diameter of the welding chamber 22 is equal to the large diameter end of the expansion hole 21, the diameter of the working belt 23 is smaller than the diameter of the welding chamber 22, the aluminum alloy billet is gathered in the welding chamber 22 and welded, the extrusion barrel 1 or the extrusion die 2 is provided with a spiral stirring structure 3, the spiral stirring structure 3 includes a plurality of cavities 31, and the ends of the cavities 31 along the extrusion forward direction are closed. The aluminum alloy billet is introduced from the end of the extrusion barrel 1 away from the extrusion die 2, flows in the direction of the extrusion die 2, and the cavity 31 extends along the extrusion forward direction. When the aluminum alloy billet reaches the spiral stirring structure 3, it needs to flow from the front end of the cavity 31 to the end of the cavity 31. The cross-section of the cavity 31 can be circular, elliptical, polygonal and irregular, and can be set as needed. Of course, the simpler the cross-section of the cavity 31, the better the diversion bridge that separates the cavity 31 is set. In the illustration of this embodiment and the following text description, the spiral stirring structure 3 is set in the extrusion barrel 1 for example.

[0038] The device for removing oxide scale during the extrusion process of aluminum alloy proposed in this embodiment is provided with a spiral stirring structure 3 in the extrusion barrel 1 or the extrusion die 2. The spiral stirring structure 3 includes a plurality of cavities 31. The ends of the cavities 31 along the extrusion forward direction are closed. The oxide scale on the aluminum alloy billet is broken by the plurality of cavities 31, and the oxide scale is further refined by the ends of the cavities 31. The refined part of the oxide scale enters the extrusion die 2 through the cavity 31 for forming operation, so that harmful inclusions such as oxide scale play a beneficial strengthening role, reduce the generation of waste in the extrusion forming process, reduce material waste, and greatly improve the yield rate.

[0039] In some embodiments, the cross-sectional area of ​​the cavity 31 gradually decreases along the extrusion direction. The cross-sectional area (herein, the cross-sectional area is the longitudinal cross-sectional area) of the cavity 31 gradually decreases along the extrusion direction, so that the oxide scale is gradually refined from the outer periphery to the inner circle, and the refinement degree of the oxide scale is improved, so that more of the oxide scale is converted into beneficial raw materials, reducing material waste and improving the yield rate.

[0040] In some embodiments, the cross-sectional area of ​​the aluminum alloy billet is S, the number of the cavities 31 is N, the cross-sectional area of ​​the front end of the cavity 31 is S1, S / 6N≤S1<S / N, and the cross-sectional area of ​​the end of the cavity 31 is less than or equal to 200mm 2 By setting this parameter, the oxide scale is initially broken into a cross-sectional area of ​​S1. Under this size, the cavity 31 has a better effect on breaking the oxide scale. Then, the oxide scale in each cavity 31 is gradually refined from the outer circle to the inner circle to less than or equal to 200mm. 2 , so that the oxide scale can be converted into beneficial raw materials as much as possible, reducing material waste.

[0041] In some embodiments, the contour of the cavity 31 along the extrusion direction is a straight line or a curve. Figure 4 As shown, it can be seen from the cross section of the spiral stirring structure 3 that the contour trend of the cavity 31 along the extrusion forward direction can be a straight line, and the straight line has better guiding performance for the aluminum alloy billet; Figure 2 and Figure 3 As shown, it can be seen from the cross-section of the spiral stirring structure 3 that the contour of the cavity 31 along the extrusion forward direction can be a curve. For the spiral stirring structure 3 of the same length, more aluminum alloy billets can be placed in the cavity 31, thereby improving the efficiency of aluminum alloy extrusion.

[0042] In some embodiments, the cavity 31 is formed by a plurality of shunt bridges. The shape and size of each shunt bridge are the same or different, and the shunt bridges are highly flexible in design. The width of the shunt bridge can be set as required to meet the load requirements according to different flow requirements, thereby improving the reliability and stability of the device.

[0043] In some embodiments, the shapes and sizes of the plurality of cavities 31 are the same. By keeping the shapes and sizes of the plurality of diversion bridges completely consistent, a uniform and stable diversion effect can be achieved under specific process requirements, ensuring that the flow characteristics of the material in each cavity 31 are the same.

[0044] In some embodiments, the shapes and sizes of the plurality of cavities 31 are different. Through the above arrangement, the complex requirements of some special processes for different flow rates and flow velocities can be met, thereby improving the application scope and adaptability of the device.

[0045] In some embodiments, Figure 3 As shown, the cavity 31 is divided into a plurality of channels 32 in the extrusion forward direction. By dividing the cavity 31 into a plurality of channels 32 in the extrusion forward direction, this multi-stage flow dividing design can, on the one hand, further divide and refine the billet during the extrusion flow process, and on the other hand, provide a plurality of channels 32 to reduce the metal flow resistance, reduce the required extrusion force, and further refine the material processing process.

[0046] In some embodiments, the inner wall of the cavity 31 may be a smooth inner wall, and the flow resistance of the aluminum alloy billet in the cavity 31 is relatively small, so that material flow can be achieved under lower extrusion pressure conditions, reducing the requirement for the tonnage of the extrusion equipment and reducing costs.

[0047] In other embodiments, Figure 4 As shown, the inner wall of the cavity 31 is provided with a protrusion structure 33. By adding the protrusion structure 33 on the inner wall, the stirring effect can be significantly enhanced, the crushing effect of the oxide scale can be improved, and the oxide scale can be further refined, so that more oxide scale can be converted into beneficial raw materials, reducing material waste.

[0048] In some embodiments, the end of the cavity 31 can cooperate with the diversion hole of the extrusion die 2 to optimize the material flow mode and path, so that the flow resistance of the aluminum alloy is smaller, the material flow can be achieved under lower extrusion pressure conditions, the requirement for the tonnage of the extrusion equipment is reduced, and the cost can be reduced.

[0049] Based on the same concept, the second embodiment of the present invention is combined with Figure 6 As shown, a method for removing oxide scale during aluminum alloy extrusion is provided, using the device for removing oxide scale during aluminum alloy extrusion as described in the first aspect of the embodiment, comprising:

[0050] Step S1: introducing aluminum alloy billet through extrusion cylinder 1;

[0051] Step S2: breaking the oxide scale on the aluminum alloy billet through the plurality of cavities 31;

[0052] Step S3: The oxide scale is further refined through the end of the cavity 31 so that the refined oxide scale is dispersedly distributed, and part of the refined oxide scale enters the extrusion die 2 through the cavity 31 for forming operation.

[0053] The method for removing oxide scale during the aluminum alloy extrusion process proposed in this embodiment breaks the oxide scale on the aluminum alloy billet through multiple cavities 31, and further refines the oxide scale through the end of the cavity 31. The refined part of the oxide scale enters the extrusion die 2 through the cavity 31 for forming operation, so that harmful inclusions such as oxide scale play a beneficial strengthening role, reduce the generation of waste in the extrusion forming process, reduce material waste, and greatly improve the yield rate.

[0054] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A device for removing oxide scale during aluminum alloy extrusion, characterized in that: It includes an extrusion barrel and an extrusion die; the extrusion barrel is connected to the extrusion die, and a spiral stirring structure is provided in the extrusion barrel or the extrusion die. The spiral stirring structure includes a plurality of cavities, and the ends of the cavities along the extrusion forward direction are closed.

2. The device for removing oxide scale during aluminum alloy extrusion according to claim 1, characterized in that: The cross-sectional area of ​​the cavity gradually decreases along the extrusion direction.

3. The device for removing oxide scale in the aluminum alloy extrusion process according to claim 2, characterized in that: The cross-sectional area of ​​the aluminum alloy billet is S, the number of the cavities is N, the cross-sectional area of ​​the front end of the cavity is S1, S / 6N≤S1<S / N, and the cross-sectional area of ​​the end of the cavity is less than or equal to 200mm 2 .

4. The device for removing oxide scale during aluminum alloy extrusion as claimed in claim 3, characterized in that: The contour of the cavity along the extrusion forward direction is a straight line or a curve.

5. The device for removing oxide scale during aluminum alloy extrusion as claimed in claim 1, characterized in that: The cavity is divided and formed by a plurality of diverter bridges.

6. The device for removing oxide scale during aluminum alloy extrusion as claimed in claim 5, characterized in that: The plurality of cavities have the same shape and size.

7. The device for removing oxide scale during aluminum alloy extrusion as claimed in claim 5, characterized in that: The shapes and sizes of the plurality of cavities are different.

8. The device for removing oxide scale during aluminum alloy extrusion as claimed in claim 1, characterized in that: The cavity is divided into a plurality of channels in the extrusion advancing direction.

9. The device for removing oxide scale during aluminum alloy extrusion according to any one of claims 1 to 8, characterized in that: The inner wall of the cavity is provided with a convex structure.

10. A method for removing oxide scale during aluminum alloy extrusion, using the device for removing oxide scale during aluminum alloy extrusion according to any one of claims 1 to 9, characterized in that: include: Introducing the aluminum alloy billet through the extrusion barrel; The oxide scale on the aluminum alloy billet is broken by using multiple cavities; The oxide scale is further refined through the end of the cavity, so that the refined oxide scale is dispersedly distributed, and part of the refined oxide scale enters the extrusion die through the cavity for forming operation.

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