Method for measuring the tail length of aluminum alloy rods and its applications

Abstract

The application discloses a method for measuring the tail contraction length of an aluminum alloy rod and application thereof, and relates to the technical field of aluminum alloy extrusion detection. The aluminum alloy rod is obtained by extruding an aluminum alloy casting rod through a forward extrusion process. During the extrusion, the aluminum alloy casting rod flows through an extrusion cylinder and an extrusion die in sequence, the extrusion is stopped at the end of the extrusion, and an extrusion pressure residue is reserved in the extrusion cylinder. The method comprises the following steps: respectively measuring or obtaining the rod diameter of the aluminum alloy rod, the length of the aluminum alloy casting rod, the cylinder diameter of the extrusion cylinder, the rod diameter of the aluminum alloy casting rod and the thickness of the extrusion pressure residue; and then calculating the tail contraction length. Based on the above method, a large number of tail contraction length verification and batch inspection work can be avoided, the production process is simplified, manpower and material resources are saved, and high production efficiency is achieved in the rod extrusion production.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of aluminum alloy extrusion detection, and particularly relates to a method for measuring the tail contraction length of an aluminum alloy rod and application thereof. BACKGROUND

[0002] In the forward extrusion of an aluminum alloy, tail contraction is a defect that enters the product interior due to the radial flow and circular flow of the metal at the end of the extrusion, and the defect is the surface oxide, lubricant and dirt, bubbles, segregation nodules and the like of the ingot, which has a certain rule to destroy the continuity and density of the product organization. In production, the solid material must be cut off the organizational defects. In the extrusion production, the extrusion test needs to be carried out, and the sample plate is sawed section by section for low-magnification inspection, so as to determine the tail contraction length of the product, which consumes a lot of manpower and time. SUMMARY

[0003] The technical problem to be solved by the present application is to provide a method for measuring the tail contraction length of an aluminum alloy rod, which can quickly determine the tail contraction length of the aluminum alloy rod after extrusion, and lay a good foundation for subsequent processing.

[0004] In order to solve the above technical problem, the present application provides a method for measuring the tail contraction length of an aluminum alloy rod, the aluminum alloy rod is obtained by extruding an aluminum alloy cast rod through a forward extrusion process, and the aluminum alloy cast rod flows through an extrusion cylinder and an extrusion die in turn during extrusion, the extrusion is stopped at the end of the extrusion, and an extrusion pressure residue is retained in the extrusion cylinder; the measuring method comprises:

[0005] The rod diameter of the aluminum alloy rod, the length of the aluminum alloy cast rod, the cylinder diameter of the extrusion cylinder, the rod diameter of the aluminum alloy cast rod and the thickness of the extrusion pressure residue are measured or obtained respectively;

[0006] The tail contraction length is calculated according to the following formula:

[0007]

[0008] Wherein, l is the tail contraction length, L is the length of the aluminum alloy cast rod, d is the diameter of the aluminum alloy rod, D is the rod diameter of the aluminum alloy cast rod, D is the cylinder diameter of the extrusion cylinder, h is the thickness of the extrusion pressure residue, and K is a constant, and the value range of K is 0.18-0.2.

[0009] As an improvement of the above technical scheme, when the aluminum alloy cast rod is 6063 aluminum alloy, K is 0.18;

[0010] When the aluminum alloy cast rod is 6005 aluminum alloy, K is 0.185;

[0011] When the aluminum alloy cast rod is 6061 aluminum alloy, K is 0.192;

[0012] K is 0.198 when the aluminum alloy cast bar is 6082 aluminum alloy.

[0013] As an improvement of the above technical solution, the extrusion ratio of the aluminum alloy cast bar is calculated according to the following formula:

[0014]

[0015] wherein λ is the extrusion ratio, d is the diameter of the aluminum alloy bar, is the barrel diameter of the extrusion barrel;

[0016] The value range of λ is 10-80.

[0017] As an improvement of the above technical solution, the extrusion speed is 3-15 m / min.

[0018] As an improvement of the above technical solution, the temperature of the aluminum alloy cast bar is 480-520℃ during extrusion, and the temperature of the extrusion barrel is 430-470℃.

[0019] As an improvement of the above technical solution, the extrusion die comprises a die body and a die pad connected with the die body, the die body is provided with a flow guide hole, a die hole and a hollow cutter which are sequentially communicated, and the die pad is provided with a flow channel; the aluminum alloy cast bar sequentially flows through the flow guide hole, the die hole, the hollow cutter and the flow channel;

[0020] The diameter of the flow guide hole is 15-30 mm larger than the hole diameter of the die hole, and the flow guide depth of the flow guide hole is 15-30 mm.

[0021] As an improvement of the above technical solution, the flow guide hole is provided with an annular groove near the die hole, the diameter of the annular groove is 3-10 mm larger than the diameter of the flow guide hole, and the length of the annular groove is 7-15 mm.

[0022] As an improvement of the above technical solution, the inner side of the die hole is a working belt, and the length of the working belt is 5-10 mm.

[0023] As an improvement of the above technical solution, the hollow cutter comprises a first-stage hollow cutter arranged near the die hole and a second-stage hollow cutter arranged near the flow channel, and the diameter of the second-stage hollow cutter is larger than the diameter of the first-stage hollow cutter.

[0024] The flow guide hole, the die hole, the first-stage hollow cutter, the second-stage hollow cutter and the flow channel are coaxially arranged.

[0025] Correspondingly, the application also discloses the application of the above-mentioned method for measuring the tail contraction length of the aluminum alloy bar in the following (1) or (2):

[0026] (1) post-processing of the aluminum alloy extruded part;

[0027] (2) Aluminum alloy extrusion die design.

[0028] The present application has the following advantages:

[0029] The method for measuring the tail contraction length of the aluminum alloy rod directly calculates the tail contraction length by the rod diameter of the aluminum alloy rod, the length of the aluminum alloy casting rod, the barrel diameter of the extrusion barrel, the rod diameter of the casting rod and the thickness of the extrusion surplus: avoids a large amount of tail contraction length verification and batch inspection work, simplifies the production process, saves manpower and material resources, and has high production efficiency in the production of rod extrusion. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 is a structural schematic diagram of the extrusion die in an embodiment of the present application;

[0031] Figure 2 is a physical picture of the extruded rod sample after alkaline etching in embodiment 1 of the present application. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical scheme and advantages of the present application clearer, the present application will be further described in detail below with specific embodiments.

[0033] The present application discloses a method for measuring the tail contraction length of an aluminum alloy rod, which specifically comprises measuring or obtaining the rod diameter of the aluminum alloy rod, the length of the aluminum alloy casting rod, the barrel diameter of the extrusion barrel, the rod diameter of the aluminum alloy casting rod and the thickness of the extrusion surplus, respectively; and then calculating the tail contraction length according to the following formula:

[0034]

[0035] Wherein, l is the tail contraction length, L is the length of the aluminum alloy casting rod, d is the diameter of the aluminum alloy rod, D is the rod diameter of the aluminum alloy casting rod, D is the barrel diameter (inner diameter) of the extrusion barrel, h is the thickness of the extrusion surplus, and K is a constant with a value range of 0.18-0.2.

[0036] Wherein, the aluminum alloy rod is obtained by extruding the aluminum alloy casting rod through a forward extrusion process. During extrusion, the aluminum alloy casting rod flows through the extrusion barrel and the extrusion die in turn, and the extrusion surplus is retained in the extrusion barrel after stopping extrusion at the end of extrusion. It should be noted that a certain amount of aluminum alloy is retained in the extrusion die and the extrusion barrel after stopping extrusion, and the part retained in the extrusion barrel is the extrusion surplus. The extrusion barrel retreats, the extrusion surplus is removed from the extrusion barrel, and the extrusion surplus is actively sheared between the extrusion barrel and the extrusion die by shearing equipment, so as to take out the extrusion surplus. After taking out the extrusion surplus, a new aluminum alloy casting rod is loaded for the next round of extrusion. That is, the stopping of extrusion in the present application does not mean complete stopping of extrusion, but refers to the stage of stopping the extrusion process in the middle of extruding different aluminum alloy casting rods.

[0037] The determination method of the present application can be applied to extruded bars based on a forward extrusion process.

[0038] Specifically, when the aluminum alloy cast bar is 6063 aluminum alloy, K is 0.18; when the aluminum alloy cast bar is 6005 aluminum alloy, K is 0.185; when the aluminum alloy cast bar is 6061 aluminum alloy, K is 0.192; and when the aluminum alloy cast bar is 6082 aluminum alloy, K is 0.198. By controlling the value of K, the influence of the material of the aluminum alloy bar on the tail contraction length can be considered, and the accuracy of the determination is improved.

[0039] Specifically, in order to more accurately determine the tail contraction length of the aluminum alloy bar, the specific process parameters in the extrusion process need to be controlled. Specifically, the extrusion ratio is controlled to be 10-80, the extrusion speed is controlled to be 3-15 m / min, the temperature of the aluminum alloy cast bar is controlled to be 480-520℃, and the temperature of the extrusion cylinder is controlled to be 430-470℃. Among them, the extrusion ratio is calculated according to the following formula:

[0040]

[0041] wherein λ is the extrusion ratio, d is the diameter of the aluminum alloy bar, is the barrel diameter of the extrusion cylinder.

[0042] Specifically, the determination method of the present application can be applied to various types of bar molds, such as the flat mold commonly used in the art. Preferably, in one embodiment of the present application, referring to Figure 1 , the extrusion mold comprises a mold body 1 and a mold pad 2 connected to the mold body 1, the mold body 1 is provided with a flow guide hole 11, a mold hole 12 and an empty knife 13 which are communicated in sequence, and the mold pad 2 is provided with a flow channel 21; the aluminum alloy cast bar flows through the flow guide hole 11, the mold hole 12, the empty knife 13 and the flow channel 21 in sequence. Among them, the flow guide hole 11 is in a straight cylinder shape, that is, the mold angle is 90°; the flow guide depth of the flow guide hole 11 (i.e. the length α of the flow guide hole 11) is 15-30 mm, and its diameter (β) is 15-30 mm larger than the diameter of the mold hole 12. This shallow right-angle type feeding flow guide hole can avoid excessive aluminum storage at the feeding port, causing long head-tail material transverse welding (organization defect also known as "delamination") at the head of the extruded product, and can reduce the length of the head waste, so that the process waste is concentrated at the tail end of the tail contraction, which not only improves the accuracy of the calculation of the tail contraction length, but also makes the subsequent processing (sawing removal, etc.) more simple.

[0043] The flow guide hole 11 is provided with an annular groove 14 near the die hole 12, the diameter (gamma) of which is 3-10mm larger than the diameter (beta) of the flow guide hole 11, and the length is 7-15mm. When the extrusion pressure shear is carried out after the extrusion is stopped, the aluminum alloy embedded in the annular groove 14 has a certain adhesion resistance, which avoids the shearing of the aluminum storage in the die flow guide hole 11 when the extrusion pressure shear is carried out, thereby ensuring the accuracy of the subsequent extrusion pressure thickness measurement, further improving the accuracy of the tail length measurement, and facilitating the subsequent continuous extrusion.

[0044] The die hole 12 is in a straight cylinder shape, and the inner side is a working belt 12a. The length of the working belt 12a is 5-10mm.

[0045] The die hole 12 is in a straight cylinder shape, and the inner side is a working belt 12a. The length of the working belt 12a is 5-10mm.

[0046] Based on the above-mentioned tail length measurement method of the application, the tail length can be quickly and accurately determined. The data basis is provided for the aluminum alloy extrusion and post-processing. For example, after the tail length is determined, a sawing device can be directly added at the extrusion outlet to cut off the tail part, so that the standardization and standardization management from the production source are realized. For another example, the tail length of the new extrusion die can be quickly evaluated according to the measurement method, and then the data basis is provided for the design improvement of the extrusion die.

[0047] Correspondingly, the application also discloses an extrusion method of an aluminum alloy cast bar, which comprises the following steps:

[0048] S1: preheating the aluminum alloy cast bar and the extrusion cylinder;

[0049] Specifically, the aluminum alloy cast bar is preheated to 480-520 DEG C, and the extrusion cylinder is preheated to 430-470 DEG C.

[0050] S2: extruding the preheated aluminum alloy cast bar, wherein the aluminum alloy cast bar flows through the extrusion cylinder and the extrusion die in sequence during the extrusion, and an aluminum alloy bar blank is obtained;

[0051] The extrusion die is the same as the above-mentioned one. The extrusion ratio is 10-80, and the extrusion speed is 3-15m / min.

[0052] S3: quenching the aluminum alloy bar blank;

[0053] S4: sawing the quenched bar blank to remove the tail part of the tail part, and obtaining an aluminum alloy bar product.

[0054] Specifically, the degree of the tailing portion is calculated according to the following formula:

[0055]

[0056] wherein, l is the tailing length, L is the length of the aluminum alloy cast bar, d is the diameter of the aluminum alloy bar, D is the bar diameter of the aluminum alloy cast bar, is the barrel diameter of the extrusion barrel, h is the thickness of the extrusion excess, and K is a constant, which ranges from 0.18 to 0.2.

[0057] The application is further described below with specific examples:

[0058] Example 1

[0059] The present example provides a method for measuring the tailing length of an aluminum alloy bar. Specifically, the aluminum alloy bar is made of 6061 aluminum alloy and is obtained by forward extrusion process of an aluminum alloy cast bar. The mold structure used in the extrusion is shown in Figure 1 Specifically, the extrusion mold includes a mold body 1 and a mold pad 2 connected to the mold body 1. The mold body 1 is provided with a flow guide hole 11, a mold hole 12, a first level air knife 13a and a second level air knife 13b which are sequentially communicated, and the mold pad 2 is provided with a flow channel 21. The flow hole 11, the mold hole 12, the first level air knife 13a, the second level air knife 13b and the flow channel 21 are coaxially arranged. The flow guide hole 11 is a straight cylinder, i.e. the mold angle is 90°. The flow guide depth of the flow guide hole 11 (i.e. the length of the flow guide hole 11) is 30mm, and its diameter is 30mm larger than that of the mold hole 12. The flow guide hole 11 is provided with an annular groove 14 near the mold hole 12, which has a diameter of 5mm larger than that of the flow guide hole 11 and a length of 15mm. The mold hole 12 is a straight cylinder, and its inner side is a working belt 12a. The length of the working belt 12a is 9mm.

[0060] The extrusion process conditions are as follows: the extrusion speed is 8m / min, the temperature of the aluminum alloy cast bar is 500℃, the temperature of the extrusion barrel is 460℃, and the extrusion ratio is 45.65.

[0061] After extrusion, the diameter of the aluminum alloy bar is 74mm; the barrel diameter of the extrusion barrel is 500mm, the bar diameter of the aluminum alloy cast bar is 482mm, and the length is 1100mm; the thickness of the extrusion excess is 30mm.

[0062] The tailing length is:

[0063]

[0064] The sample bars of 1m, 2m, 3m, 4m, 5m, 6m, 7m and 8m are respectively taken for alkali washing, and the actual figure after alkali washing is as shown in Figure 2The results are shown in the figure. From left to right, the figure shows 8m, 7m, 6m, 5m, 4m, 3m, 2m, and 1m. As can be seen from the figure, the 7m low-power tissue shows a tail contraction, while the 8m low-power tissue shows no tail contraction, and the tail contraction length is determined to be greater than 7m and less than 8m, which is consistent with the calculated value.

[0065] The above describes the preferred embodiments of the application. It should be noted that those skilled in the art can make several improvements and refinements without departing from the principles of the application, and these improvements and refinements are also considered within the protection scope of the application.

Claims

1. A method for measuring the tail length of an aluminum alloy rod, the aluminum alloy rod being obtained by forward extrusion of an aluminum alloy cast rod, the aluminum alloy cast rod flowing through an extrusion cylinder and an extrusion die in sequence, and extrusion being stopped at the end of extrusion, and an extrusion residue being left in the extrusion cylinder, characterized in that, The determination method comprises: respectively determining or obtaining the rod diameter of the aluminum alloy rod, the length of the aluminum alloy cast rod, the barrel diameter of the extrusion barrel, the rod diameter of the aluminum alloy cast rod and the thickness of the extrusion pressure excess; calculating the tail contraction length according to the following formula: wherein, l is the tail contraction length, L is the length of the aluminum alloy cast rod, d is the diameter of the aluminum alloy rod, D is the rod diameter of the aluminum alloy cast rod, φ is the barrel diameter of the extrusion barrel, h is the thickness of the extrusion pressure excess, K is a constant, and the value range of K is 0.18-0.

2.

2. The method of determining the stub length of an aluminum alloy bar according to claim 1, wherein When the aluminum alloy cast rod is 6063 aluminum alloy, K is 0.18; When the aluminum alloy cast rod is 6005 aluminum alloy, K is 0.185; When the aluminum alloy cast rod is 6061 aluminum alloy, K is 0.192; When the aluminum alloy cast rod is 6082 aluminum alloy, K is 0.

198.

3. The method of determining the stub length of an aluminum alloy bar according to claim 1, wherein The extrusion ratio of the aluminum alloy cast rod is calculated according to the following formula: wherein, λ is the extrusion ratio, d is the diameter of the aluminum alloy rod, and φ is the barrel diameter of the extrusion barrel; The value range of λ is 10-80.

4. The method of determining the stub length of an aluminum alloy bar according to claim 1, wherein The extrusion speed is 3-15 m / min.

5. The method of determining the stub length of an aluminum alloy bar according to claim 1, wherein During extrusion, the temperature of the aluminum alloy cast rod is 480-520℃, and the temperature of the extrusion barrel is 430-470℃.

6. The method of determining the stub length of an aluminum alloy bar according to claim 1, wherein The extrusion die comprises a die body and a die pad connected with the die body, the die body is provided with a flow guide hole, a die hole and a hollow cutter which are sequentially communicated, and the die pad is provided with a flow channel; the aluminum alloy cast rod sequentially flows through the flow guide hole, the die hole, the hollow cutter and the flow channel; The diameter of the flow guide hole is 15-30 mm larger than the hole diameter of the die hole, and the flow guide depth of the flow guide hole is 15-30 mm.

7. The method of determining the stub length of an aluminum alloy bar according to claim 6, wherein The flow guide hole is provided with an annular groove near the die hole, the diameter of the annular groove is 3-10 mm larger than the diameter of the flow guide hole, and the length of the annular groove is 7-15 mm.

8. The method of determining the stub length of an aluminum alloy bar according to claim 6, wherein The inner side of the die hole is a working belt, and the length of the working belt is 5-10 mm.

9. The method of determining the stub length of an aluminum alloy bar according to claim 6, wherein The hollow cutter comprises a first-stage hollow cutter arranged near the die hole and a second-stage hollow cutter arranged near the flow channel, and the diameter of the second-stage hollow cutter is larger than the diameter of the first-stage hollow cutter; The flow guide hole, the die hole, the first-stage hollow cutter, the second-stage hollow cutter and the flow channel are coaxially arranged.

10. The application of the tail contraction length determination method of the aluminum alloy rod according to any one of claims 1-9 in the following (1) or (2): (1) aluminum alloy extrusion part post-processing; (2) aluminum alloy extrusion die design.

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