A method for preparing an aluminum alloy sample and its application

Abstract

The present invention relates to a method for preparing an aluminum alloy sample and its application. The method for preparing the aluminum alloy sample includes machining an aluminum alloy sheet and strip product into an aluminum alloy test blank with dimensions meeting the requirements of fracture inspection; machining a clad sample blank with dimensions meeting the requirements of fracture inspection from a sheet and strip product having a thickness specification greater than that of the aluminum alloy test sample; axially centering and opening a full-thickness through groove in the thickness direction of the clad sample blank according to the contour dimensions of the aluminum alloy test sample, and pressing the aluminum alloy test blank into the through groove; planing an opening on one side of the aluminum alloy test blank close to the through groove and at the thickness center to obtain the aluminum alloy sample; and performing a splitting test by applying pressure to the opening. The clad sample blank of the present invention can effectively achieve loading force constraint and avoid lateral deflection of the aluminum alloy test blank during pressure loading.

Description

Technical Field

[0001] The present invention relates to the technical field of aluminum alloy inspection, and particularly relates to a method for preparing an aluminum alloy sample and its application. Background Art

[0002] Macrostructure fracture oxide film inspection is an important part of the re-inspection of wrought aluminum and aluminum alloy products. It is usually carried out in accordance with GB / T 3246.2 "Methods for the inspection of the structure of wrought aluminum and aluminum alloy products - Part 2: Methods for macrostructure inspection", which is used to inspect and judge whether there are various defects in the structure of alloy ingots and various products (sheet and strip materials, extruded products, forgings), and is an important structure inspection method that can meet the usage requirements of relevant parties.

[0003] For the fracture oxide film inspection of alloy ingots, sheet and strip materials, extruded products, forgings, etc., it is usually carried out by breaking or splitting. The sampling methods and sample sizes of the specimens used for the fracture oxide film structure inspection of different types of products are different. For sheet and strip materials, according to the GB / T 3246.2 standard, a transverse specimen blank should be cut along the direction perpendicular to the rolling direction of the product. The width of the specimen blank should be preferably 30 mm, and then it should be longitudinally cut into several sections. The thickness of the product that needs to be inspected for the fracture structure should be not less than 25 mm. The side of the specimen blank is grooved, and the groove depth should not be greater than 1 / 3 of the width of the blank, and the specimen blank is broken or split at one time on a press, as Figure 1 shown, the GB / T 3246.2 standard stipulates that the indenter 1 provides pressure on the specimen 2 from top to bottom. The specimen 2 is placed on the support seat 3, and the support seat 3 is placed on the workbench 4, and then the breaking and splitting tests as Figure 1 shown can be realized. However, when the thickness of the sheet and strip material product is less than 25 mm, due to the limitation of the product thickness, it is extremely easy to occur sample loading skew during the splitting test, and the effective splitting of the sample cannot be achieved, and an effective fracture oxide film inspection plane cannot be obtained, which is not conducive to the macrostructure fracture oxide film inspection of aluminum alloy sheet and strip products. Summary of the Invention

[0004] (1) Technical problems to be solved

[0005] In the first aspect of the embodiments of the present invention, a method for preparing an aluminum alloy sample is provided, including preparing an aluminum alloy test blank and a coated sample blank, pressing the aluminum alloy test blank into the coated sample blank, and then grooving to obtain an aluminum alloy sample. The coated sample blank of the present invention can effectively realize the constraint of the loading force and avoid the lateral skew of the pressure loading of the aluminum alloy test blank.

[0006] In the second aspect of the embodiments of the present invention, the application of the aluminum alloy sample is provided, which is used for the macrostructure inspection of the fracture oxide film of sheet and strip materials. The coated sample blank of the present invention can effectively realize the constraint of the loading force and avoid the lateral skew of the pressure loading of the aluminum alloy test blank.

[0007] (2) Technical solution

[0008] In the first aspect of the embodiment of the present invention, a method for preparing an aluminum alloy sample is proposed, which includes the following steps:

[0009] Step 1: Prepare an aluminum alloy test blank with dimensions meeting the requirements of fracture inspection from an aluminum alloy sheet and strip product through machining;

[0010] Step 2: Prepare a cladding sample blank with dimensions meeting the requirements of fracture inspection from a sheet and strip product with a thickness specification greater than that of the aluminum alloy test sample through machining;

[0011] Step 3: Axially center and open a full-thickness through slot in the thickness direction of the cladding sample blank according to the contour dimensions of the aluminum alloy test sample, and press the aluminum alloy test blank into the through slot;

[0012] Step 4: Plane the side of the aluminum alloy test blank close to the through slot and at the thickness center to obtain the aluminum alloy sample;

[0013] Step 5: Apply pressure to the plane to conduct a splitting test.

[0014] Furthermore, the thickness range of the aluminum alloy test blank is 15 mm to 25 mm.

[0015] Furthermore, the thickness of the cladding sample blank is not less than 40 mm.

[0016] Furthermore, the cladding sample blank is made of the same grade aluminum alloy material as the aluminum alloy test blank or the cladding sample blank is made of other alloy sheet and strip materials with strength similar to that of the aluminum alloy test blank.

[0017] Furthermore, the depth of the plane groove of the aluminum alloy test blank in Step 4 is not greater than 1 / 3 of the width of the aluminum alloy test blank.

[0018] Furthermore, Step 5 includes: Install the indenter for the fracture splitting test on a universal testing machine, place the plane side of the aluminum alloy sample obtained in Step 4 on the support seat, and the universal testing machine applies pressure to split the aluminum alloy test blank along the plane.

[0019] In the second aspect of the embodiment of the present invention, an application of an aluminum alloy sample is proposed, which is used for low-magnification inspection of the fracture oxide film of sheet and strip materials.

[0020] (3) Advantageous effects

[0021] The present invention forms an aluminum alloy sample by arranging a coated sample blank to coat an aluminum alloy test blank. In this way, even if the thickness of the aluminum alloy test blank is less than 25 mm, due to the coating of the coated sample blank, when performing a splitting test, the coated sample blank can effectively realize loading force constraint, thereby avoiding lateral deflection of the aluminum alloy test blank due to pressure loading, and overcoming the restriction in the GB / T3246.2 standard that the thickness of the plate and strip materials that need to undergo fracture microstructure inspection should be no less than 25 mm. This effectively solves the problem that plate and strip products with a thickness of less than 25 mm are prone to sample loading deflection, making it impossible to achieve effective sample splitting, obtain an effective fracture oxide film inspection plane, and perform low-magnification fracture oxide film microstructure re-inspection.

[0022] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments of the present invention are 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 creative work.

[0024] Figure 1 This is a schematic diagram of the folding and splitting fracture test of aluminum alloy samples in the GB / T3246.2 standard.

[0025] Figure 2 It is a schematic flow chart of a method for preparing an aluminum alloy sample in one embodiment of the present invention.

[0026] Figure 3 It is a schematic diagram of the structure of an aluminum alloy sample in one embodiment of the present invention.

[0027] Figure 4 It is a diagram of the fracture splitting test process in one embodiment of the present invention.

[0028] Figure 5 This is a real picture of the fracture of the aluminum alloy sample with low-magnification structure and oxide film inspection test piece.

[0029] In the figure: indenter 1, test specimen 2, support seat 3, workbench 4, aluminum alloy test blank 5, coated sample blank 6, aluminum alloy sample 7. DETAILED DESCRIPTION

[0030] The embodiments of the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. The following detailed description of the embodiments and the accompanying drawings are used to exemplarily illustrate the principles of the present invention, but cannot be used to limit the scope of the present invention, that is, the present invention is not limited to the described embodiments, and covers any modifications, substitutions, and improvements of parts, components, and connection methods without departing from the spirit of the present invention.

[0031] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other.

[0032] The following will refer to the attached Figure 2 - attached Figure 5 and combine with embodiments to detail the present application.

[0033] A method for preparing an aluminum alloy sample 7 according to the first aspect of the embodiments of the present invention, referring to the attached Figure 2 as shown, includes the following steps:

[0034] Step 1: Prepare an aluminum alloy test blank 5 with dimensions meeting the requirements of fracture inspection from an aluminum alloy sheet and strip product through machining.

[0035] Step 2: Prepare a cladding sample blank 6 with dimensions meeting the requirements of fracture inspection from a sheet and strip product with a thickness specification greater than that of the aluminum alloy test sample through machining.

[0036] Step 3: Axially center and open a full-thickness through slot in the thickness direction of the cladding sample blank 6 according to the contour dimensions of the aluminum alloy test sample, and press the aluminum alloy test blank 5 into the through slot.

[0037] Step 4: Perform grooving on one side of the aluminum alloy test blank 5 near the through slot and at the thickness center to obtain the aluminum alloy sample 7.

[0038] Step 5: Apply pressure to the groove for a splitting test.

[0039] At present, according to GB / T3246.2 standard, low-magnification microstructure re-inspection of fracture oxide film can be carried out on plate and strip products with a thickness greater than 25 mm. However, when the thickness of the plate and strip products is less than 25 mm, due to the relatively thin thickness of such products, lateral loading deviation is very likely to occur during the splitting test of the processed re-inspection sample, and the sample cannot be effectively split along the rolling surface, resulting in the inability to re-inspect plate and strip products with a thickness of less than 25 mm. Based on this actual situation, the embodiment of the present invention first prepares the aluminum alloy plate and strip product into an aluminum alloy test billet 5 that meets the required size for fracture inspection by mechanical processing (at this time, the thickness of the aluminum alloy test billet 5 can be greater than 25 mm or less than 25 mm), and then uses a plate and strip product with a thickness specification greater than the aluminum alloy test sample to prepare it into a coated sample billet 6 that meets the required size for fracture inspection by mechanical processing; then, according to the contour size of the aluminum alloy test sample, an axially centered full-thickness through-groove is opened in the thickness direction of the coated sample billet 6, and the aluminum alloy test billet 5 is pressed into the through-groove. After this step: the aluminum alloy test billet 5 is coated by the coated sample billet 6, and the coated sample billet 6 can provide support for the aluminum alloy test billet 5 when conducting inspections such as those involved in GB / T3246.2 standard; next, the embodiment of the present invention performs planing on the side of the aluminum alloy test billet 5 close to the through-groove and at the center of the thickness to obtain an aluminum alloy sample 7; finally, pressure can be applied to the planing according to the GB / T3246.2 standard method to perform a splitting test.

[0040] To summarize, the embodiment of the present invention forms an aluminum alloy sample 7 by providing a coated sample 6 to coat the aluminum alloy test billet 5. Thus, even if the thickness of the aluminum alloy test billet 5 is less than 25 mm, due to the coating of the coated sample 6, when performing the splitting test, the coated sample can effectively realize the loading force constraint, thereby avoiding lateral deviation of the aluminum alloy test billet 5. This overcomes the restriction in the GB / T3246.2 standard that the thickness of the product that requires fracture microstructure inspection of plate and strip materials should not be less than 25 mm, and effectively solves the problem that plate and strip products with a thickness of less than 25 mm are prone to sample loading deviation, making it impossible to effectively split the sample, obtain an effective fracture oxide film inspection plane, and perform low-magnification fracture oxide film microstructure re-inspection.

[0041] Specifically, according to another embodiment of the first aspect of the embodiments of the present invention, the thickness range of the aluminum alloy test blank 5 is 15 mm to 25 mm. As mentioned above, when the thickness of the aluminum alloy test blank 5 is greater than 25 mm, when applying a loading force constraint at this time, the aluminum alloy test blank 5 is not prone to lateral deflection, and the folding and splitting fracture tests can be directly carried out in accordance with the GB / T 3246.2 standard. When the thickness of the aluminum alloy test blank 5 is as low as below 25 mm, since the thickness of such products is relatively thin, when the re-inspection sample blanks processed are subjected to the splitting test, it is extremely easy to have a lateral deflection during loading, and the sample cannot be effectively split along the rolling surface. Therefore, it is necessary to apply the splitting test by the above method of the embodiments of the present invention. Of course, when the thickness of the aluminum alloy test blank 5 is below 15 mm, there is also a risk of lateral deflection during loading even if the aluminum alloy test blank 5 is coated with a coated sample blank 6. Therefore, when the thickness range of the aluminum alloy test blank 5 is 15 mm to 25 mm, due to the coating of the coated sample blank 6, during the splitting test, the coated sample blank 6 can effectively achieve the loading force constraint, avoid the lateral deflection of the aluminum alloy test blank 5, and overcome the limitation in the GB / T 3246.2 standard that the thickness of the product for which the fracture structure inspection of the strip needs to be carried out should not be less than 25 mm. Of course, in the embodiments of the present invention, the thickness of the aluminum alloy test blank 5 can be 15 mm, can be 25 mm, or can also be 20 mm, etc., which can be determined according to actual needs.

[0042] Specifically, according to yet another embodiment of the first aspect of the embodiments of the present invention, the thickness of the coated sample blank 6 is not less than 40 mm. In the embodiments of the present invention, the coated sample blank 6 is used to coat the aluminum alloy test blank 5 to ensure that during the splitting test, a loading force constraint can be applied to the aluminum alloy test blank 5 to avoid the lateral deflection of the aluminum alloy test blank 5. Therefore, the coated sample blank 6 should also have a certain structural strength and cannot deflect under the action of the loading force itself. When the thickness of the coated sample blank 6 is not less than 40 mm, when a through groove equal to the thickness of the aluminum alloy test blank 5 is opened thereon, the minimum thickness of the coated sample blank 6 is 15 mm, so that on both sides of the thickness of the aluminum alloy test blank 5, a thickness of at least 7.5 mm can be respectively set. The thickness of at least 7.5 mm on both sides can well play a role in coating the aluminum alloy test blank 5. Of course, in the embodiments of the present invention, the thickness of the coated sample blank 6 can also be 50 mm, 60 mm or 70 mm, etc. It can be determined according to needs.

[0043] Specifically, according to an embodiment of the first aspect of the present invention, the coated sample 6 is made of the same grade of aluminum alloy as the aluminum alloy test blank 5, or the coated sample 6 is made of other alloy plates and strips with similar strength to the aluminum alloy test blank 5. When the coated sample 6 is made of the same grade of aluminum alloy as the aluminum alloy test blank 5, or the coated sample 6 is made of other alloy plates and strips with similar strength to the aluminum alloy test blank 5, the hardness of the coated sample 6 and the aluminum alloy test blank 5 is the same or similar, and under the action of the loading force, the deformation coefficients and the like between them remain similar, and no uneven force will be generated between them, and then the aluminum alloy test blank 5 will not be squeezed and deformed by the coated sample 6. This is conducive to the aluminum alloy test blank 5 maintaining a stable shape during the splitting test.

[0044] Specifically, according to another embodiment of the first aspect of the embodiments of the present invention, in step 4, the depth of the planing groove of the aluminum alloy test blank 5 is not greater than 1 / 3 of the width of the aluminum alloy test blank 5. The depth of the planing groove of the aluminum alloy test blank 5 is not greater than 1 / 3 of the width of the aluminum alloy test blank 5, which meets the requirements of the GB / T3246.2 standard, and when the depth of the planing groove of the aluminum alloy test blank 5 is not greater than 1 / 3 of the width of the aluminum alloy test blank 5, it is convenient to perform a splitting test.

[0045] Specifically, according to another embodiment of the first aspect of the embodiments of the present invention, the step five includes: installing a pressure head for a fracture splitting test on a universal testing machine, placing the planed side of the aluminum alloy sample 7 obtained in step four on a support seat, and applying pressure on the universal testing machine to perform a splitting test on the aluminum alloy test blank 5 along the planed edge. The splitting test in step five can be conveniently implemented by the universal testing machine.

[0046] The application of the aluminum alloy sample 7 according to the second aspect of the embodiment of the present invention is used for the low-power microstructure inspection of the oxide film on the fracture of the plate and strip. In the embodiment of the present invention, due to the coating of the coated sample blank 6, when performing the splitting test, the coated sample blank 6 can effectively realize the loading force constraint, avoid the lateral deflection of the aluminum alloy test blank 5, overcome the restriction in the GB / T3246.2 standard that the thickness of the product that needs to be inspected for the fracture structure of the plate and strip should not be less than 25mm, and effectively solve the problem that the plate and strip products with a thickness of less than 25mm are very prone to sample loading deflection, unable to achieve effective splitting of the sample, unable to obtain an effective fracture oxide film inspection plane, and unable to perform low-power microstructure re-inspection of the fracture oxide film.

[0047] The following are several specific embodiments to illustrate the preparation method and application of the aluminum alloy sample 7 of the present invention.

[0048] Embodiment 1:

[0049] Test material: 20mm thick 2050 aluminum-lithium alloy plate

[0050] Experimental process: Processing of macrostructure fracture inspection specimens of 2050 aluminum-lithium alloy thick plates, preparation of macrostructure fracture inspection specimens and machining of assembly holes for other aluminum alloy plates and strips, and splitting test for fracture inspection. The specific implementation steps are as follows:

[0051] Step 1: According to the standard of GB / T3246.2, process a typical 2050 aluminum-lithium alloy thick plate with a thickness of 20 mm into an aluminum alloy test blank 5 with dimensions of 20 mm × 45 mm × 120 mm.

[0052] Step 2: Use a typical 2050 aluminum-lithium alloy thick plate with a thickness of 60 mm, and also process this plate and strip into a cladding specimen 6 with dimensions of 60 mm × 45 mm × 160 mm according to the standard of GB / T3246.2.

[0053] Step 3: Axially center and open a full-thickness through groove on the cladding specimen 6. The grooving dimensions are 20 mm × 45 mm × 120 mm (the same as the outer dimensions of the aluminum alloy test blank 5). Press the aluminum alloy test blank 5 into the through groove of the cladding specimen 6 to achieve an effective interference fit to obtain an aluminum alloy sample 7, and plane a groove at the 1 / 2 thickness of the aluminum alloy sample 7 according to the standard of GB / T3246.2, with the groove depth not greater than 1 / 3 of the width.

[0054] Step 4: Install the special tooling for the fracture splitting test (pressing head, support seat) on a universal testing machine. Place the aluminum alloy sample 7 on the support seat, and apply pressure with the universal testing machine to split the aluminum alloy sample 7 along the grooved surface to prepare an effective fracture surface of the aluminum alloy test blank 5 for macrostructure fracture oxide film inspection.

[0055] Example 2:

[0056] Test materials: 2xxx series or other grades of aluminum alloy

[0057] In Step 1, use a 2xxx series or other grades of aluminum alloy thick plate with a thickness less than 25 mm, and also process this plate and strip into an aluminum alloy test blank 5 with dimensions of 45 mm × 80 mm (thickness remains unchanged) according to the method specified in the macrostructure fracture splitting test of the standard GB / T3246.2.

[0058] In Step 2, use a 2xxx series or other grades of aluminum alloy thick plate with a typical thickness of 60 mm, and also process this plate and strip into a cladding specimen 6 with dimensions of 60 mm × 45 mm × 80 mm according to the method specified in the macrostructure fracture splitting test of the standard GB / T3246.2.

[0059] Step 3: Axially center and open a full-thickness through slot on the clad sample blank 6. The slot size is the same as the outer dimension of the aluminum alloy test blank 5. Press the aluminum alloy test blank 5 into the through slot of the clad sample blank 6 to achieve an effective interference fit to obtain the aluminum alloy sample 7. Then, according to the standard of GB / T3246.2, make a cut at the 1 / 2 thickness of the aluminum alloy sample 7. The slot depth is not greater than 1 / 3 of the width.

[0060] Step 4: Install the special tooling for the fracture splitting test (the indenter and the support seat) on the universal testing machine. Place the aluminum alloy sample 7 on the support seat. The universal testing machine applies pressure to split the aluminum alloy sample 7 along the cut to prepare an effective fracture surface of the aluminum alloy test blank 5 for macro-fracture oxide film inspection.

[0061] Appendix Figure 4 The figure in the middle is a on-site photo of the fracture splitting test process in the embodiment of the present invention, which reflects the installation method of the aluminum alloy sample 7 on the special tooling for the splitting test (the indenter 1 and the support seat 3) in the 21st embodiment of the present invention. Appendix Figure 5 This is a physical photo of the fracture after opening the test piece for the macro-structure fracture oxide film inspection of the aluminum alloy sample 7 in the embodiment of the present invention, which reflects the fracture morphology of the aluminum alloy sample 7 after splitting in the 2nd embodiment. It can be seen that due to the cladding of the clad sample blank 6 in the embodiment of the present invention, during the splitting test, the clad sample blank 6 can effectively realize the restraint of the loading force, avoid the lateral deflection of the aluminum alloy test blank 5, and overcome the limitation that the product thickness for which the fracture structure inspection is required for strip and sheet materials in the standard of GB / T3246.2 should not be less than 25 mm.

[0062] It should be clear that each embodiment in this specification is described in a progressive manner. For the parts that are the same or similar among the embodiments, reference can be made to each other. Each embodiment focuses on the differences from other embodiments. For the method embodiments, reference can be made to the relevant parts of the device embodiments. The present invention is not limited to the specific steps and structures described above and shown in the figures. And, for the sake of brevity, the detailed description of known method technologies is omitted here.

[0063] The above description is only for the embodiments of the present application and does not limit the present application. For those skilled in the art, the present application can have various changes and modifications without departing from the scope of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present application shall be included within the scope of the claims of the present application.

Claims

1. A method for preparing an aluminum alloy sample, characterized in that, It includes the following steps: Step 1: Prepare an aluminum alloy test blank with dimensions meeting the requirements of fracture inspection from an aluminum alloy sheet and strip product through machining; Step 2: Prepare a cladding sample blank with dimensions meeting the requirements of fracture inspection from a sheet and strip product with a thickness specification greater than that of the aluminum alloy test blank through machining. The cladding sample blank is made of the same grade aluminum alloy as the aluminum alloy test blank or the cladding sample blank is made of other alloy sheet and strip with strength similar to that of the aluminum alloy test blank; Step 3: Axially center and open a full-thickness through slot in the thickness direction of the cladding sample blank according to the contour dimensions of the aluminum alloy test blank, and press the aluminum alloy test blank into the through slot; Step 4: Make a gouge on one side of the aluminum alloy test blank close to the through slot and at the thickness center to obtain the aluminum alloy sample; Step 5: Apply pressure to the gouge for a splitting test.

2. The method for preparing an aluminum alloy sample according to claim 1, wherein The thickness range of the aluminum alloy test blank is 15 mm to 25 mm.

3. A method for preparing an aluminum alloy sample according to claim 1 or 2, characterized in that, The thickness of the cladding sample blank is not less than 40 mm.

4. A method for preparing an aluminum alloy sample according to claim 1, characterized in that, In Step 4, the depth of the gouge groove of the aluminum alloy test blank is not greater than 1 / 3 of the width of the aluminum alloy test blank.

5. A method for preparing an aluminum alloy sample according to claim 1, characterized in that, Step 5 includes: Install a fracture splitting test indenter on a universal testing machine, place the gouge side of the aluminum alloy sample obtained in Step 4 on a support seat, and the universal testing machine applies pressure to split the aluminum alloy test blank along the gouge for a splitting test.

6. Use of an aluminum alloy sample obtained by the aluminum alloy sample preparation method according to any one of claims 1-5, characterized in that, For low-power structure inspection of the fracture oxide film of sheet and strip.

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