Method for detecting high-temperature solid ductility of copper ingot

Abstract

This invention discloses a method for testing the high-temperature solid-state ductility of copper ingots, relating to the field of metal material processing performance testing technology. Addressing the problem of the lack of effective, intuitive, and low-cost methods for testing the high-temperature solid-state ductility of copper ingots in existing technologies, this invention provides a testing method comprising: processing the copper ingot to be tested into a cylindrical sample with a first volume; heating it to 300℃-800℃ and then transferring it to a preheated testing mold for hot-burning operation; after cooling and demolding, removing the flash and measuring the third volume of the formed hot-burned part; using the ratio of the third volume to the first volume as the filling integrity to evaluate ductility. The testing mold adopts a radial multi-stage flow channel structure, including a central main chamber, several primary flow channels, and secondary and tertiary flow channels respectively connected to it. By progressively reducing the cross-sectional area, the flow resistance is increased, amplifying the difference in ductility; this invention also incorporates the average distance between the filling ends of the secondary and tertiary flow channels as an auxiliary evaluation index.

Description

Technical Field

[0001] This invention relates to the field of metal material processing performance testing technology, and in particular to a method for testing the high-temperature solid-state ductility of copper ingots. Background Technology

[0002] Copper and copper alloys are widely used in hot working processes such as hot stamping and hot forging. Their solid ductility in the high-temperature range is the core factor that determines the quality of hot-worked products. Insufficient ductility will lead to incomplete filling of forgings, defects such as folding and cracks, and significantly reduce the product yield.

[0003] Currently, industry assessments of metal ductility largely focus on the liquid casting process. There is a lack of effective, intuitive, and cost-effective industrial testing methods for the ductility of copper and copper alloys during solid-state hot working. While existing thermal simulation testing machines can test parameters such as rheological stress, their high purchase and operating costs, complex operation procedures, and inability to simulate the actual filling behavior of metals in complex mold cavities make them unsuitable for meeting the practical needs of incoming material quality control in production sites and rapid laboratory testing.

[0004] Meanwhile, traditional metal testing molds have simple structures and flow channel designs, making it impossible to transform abstract solid-state ductility into quantifiable and comparable geometric parameters. They also struggle to simultaneously assess the material's flow capacity and isotropy in multiple directions, failing to provide precise technical support for optimizing thermal processing. Therefore, there is an urgent need in this field for a simple, low-cost testing method that can quantitatively assess the high-temperature solid-state ductility of copper ingots. Simultaneously, a dedicated testing mold should be designed to implement this method, using a special flow channel structure to transform metal ductility into measurable physical indicators, meeting the testing needs of production sites and laboratories. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing technologies by providing a method for detecting the high-temperature solid-state ductility of copper ingots. To achieve the above objectives, the technical solution adopted by the present invention is as follows: A method for testing the high-temperature solid-state ductility of copper ingots includes the following steps: Step 1: Process the copper ingot to be tested into a cylindrical sample with a first volume, heat the cylindrical sample to 300℃-800℃ and keep it at that temperature until the cylindrical sample is uniformly heated to obtain the heated sample. Step 2: Quickly transfer the heated sample into the preheated testing mold. The testing mold has a cavity with a second volume, and the heated sample is accommodated through the cavity. Then, perform a hot stamping operation on the heated sample. After holding the pressure, cool it to room temperature, and then eject the hot-stamped sample from the testing mold to obtain the formed hot-stamped part. Step 3: After removing the flash from the formed red-stamped part, measure the volume of the formed red-stamped part after flash removal, and record it as the third volume; The high-temperature solid-state ductility of the copper ingot under test is evaluated by the degree of filling of the sample in the test mold after heating, and the degree of filling is the ratio of the third volume to the first volume.

[0006] Furthermore, in step two, the preheating temperature of the mold is 250℃-300℃, and the holding time after the hot stamping operation is 3s-10s.

[0007] Furthermore, the testing mold includes: the upper mold assembly and the upper punch mold; The cavity of the upper mold assembly includes: a central main chamber arranged along its height direction and connected to the outside, several primary flow channels connected to the central main chamber, several secondary flow channels connected to each primary flow channel, and several tertiary flow channels connected to each primary flow channel. The central main chamber is located at the center of the upper die assembly. The primary, secondary, and tertiary runners are located at the bottom of the central main chamber. Several primary runners are equidistantly distributed along the circumferential direction of the central main chamber. The secondary runners start at the connection between the central main chamber and the primary runners. The tertiary runners start at the middle of the primary runners, and the secondary and tertiary runners are located on both sides of the primary runners. One end of the upper punch is detachably installed in the central main chamber.

[0008] Furthermore, the testing mold also includes: a lower mold assembly that is detachably disposed at the bottom of the upper mold assembly, and a lower punch; The lower die assembly has a main cavity that is coaxial with and connected to the central main cavity along its height direction, and one end of the lower punch is detachably located in the main cavity at the end away from the upper die assembly.

[0009] Furthermore, the number of primary flow channels is 4-8.

[0010] Furthermore, the extension direction of the secondary flow channel forms an angle of 30°-60° with the extension direction of the primary flow channel, and the extension direction of the tertiary flow channel forms an angle of 40°-50° with the extension direction of the primary flow channel.

[0011] Furthermore, the cross-sections of the primary flow channel, the secondary flow channel, and the tertiary flow channel are all rectangular, and the cross-sectional areas of the secondary flow channel and the tertiary flow channel are all smaller than the cross-sectional area of ​​the primary flow channel.

[0012] Furthermore, the high-temperature solid-state ductility of the copper ingot under test is also evaluated by the filling length of the formed red-formed part in the secondary flow channel and / or the filling state of the formed red-formed part in the tertiary flow channel; The filling length of the secondary flow channel is the horizontal distance from the starting point of the secondary flow channel to the filling end of the internal forming red stamping part. The filling state of the forming red stamping part in the tertiary flow channel is evaluated as fully filled, partially filled, or unfilled.

[0013] Furthermore, the diameter of the central main compartment is 15mm-200mm, and the depth of the central main compartment is 15mm-200mm; The length of the primary flow channel is 8mm-100mm, the cross-sectional width of the primary flow channel is 4mm-100mm, and the cross-sectional depth of the primary flow channel is 5mm-100mm.

[0014] For example, the diameter of the central main compartment can be selected from 15mm, 20mm, 30mm, 40mm, 50mm, 60mm, 70mm, 80mm, 90mm, 100mm, 110mm, 120mm, 130mm, 140mm, 150mm, 160mm, 170mm, 180mm, 190mm or 200mm, and the depth of the central main compartment can be selected from 15mm, 20mm, 30mm, 40mm, 50mm, 60mm, 70mm, 80mm, 90mm, 100mm, 110mm, 120mm, 130mm, 140mm, 150mm, 160mm, 170mm, 180mm, 190mm or 200mm; The length of the primary flow channel can be selected from 8mm, 10mm, 20mm, 30mm, 40mm, 50mm, 60mm, 70mm, 80mm, 90mm or 100mm; the cross-sectional width of the primary flow channel can be selected from 4mm, 10mm, 20mm, 30mm, 40mm, 50mm, 60mm, 70mm, 80mm, 90mm or 100mm; and the cross-sectional depth of the primary flow channel can be selected from 5mm, 10mm, 15mm, 20mm, 30mm, 40mm, 50mm, 60mm, 70mm, 80mm, 90mm or 100mm.

[0015] More preferably, the diameter of the central main compartment is 15mm-95mm and the depth of the central main compartment is 15mm-95mm; The length of the primary flow channel is 8mm-55mm, the cross-sectional width of the primary flow channel is 4mm-45mm, and the cross-sectional depth of the primary flow channel is 5mm-45mm.

[0016] Furthermore, the length of the secondary flow channel is 5mm-80mm, the cross-sectional width of the secondary flow channel is 2mm-50mm, and the cross-sectional depth of the secondary flow channel is 3mm-50mm. The length of the tertiary flow channel is 5mm-80mm, the cross-sectional width of the tertiary flow channel is 2mm-50mm, and the cross-sectional depth of the tertiary flow channel is 3mm-50mm.

[0017] For example, the length of the secondary flow channel can be 5mm, 10mm, 20mm, 30mm, 40mm, 50mm, 60mm, 70mm or 80mm, the cross-sectional width of the secondary flow channel can be 2mm, 5mm, 15mm, 20mm, 30mm, 40mm or 50mm, and the cross-sectional depth of the secondary flow channel can be 3mm, 8mm, 20mm, 30mm, 40mm or 50mm. The length of the tertiary flow channel can be selected from 5mm, 8mm, 10mm, 20mm, 30mm, 40mm, 50mm, 60mm, 70mm or 80mm, the cross-sectional width of the tertiary flow channel can be selected from 2mm, 5mm, 15mm, 20mm, 30mm, 40mm or 50mm, and the cross-sectional depth of the tertiary flow channel can be selected from 3mm, 5mm, 8mm, 20mm, 30mm, 40mm or 50mm.

[0018] More preferably, the length of the secondary flow channel is 5mm-45mm, the cross-sectional width of the secondary flow channel is 2mm-25mm, and the cross-sectional depth of the secondary flow channel is 3mm-25mm; the length of the tertiary flow channel is 5mm-45mm, the cross-sectional width of the tertiary flow channel is 2mm-25mm, and the cross-sectional depth of the tertiary flow channel is 3mm-25mm.

[0019] It should be noted that, in order to facilitate the flow and filling of metal and reflect the multi-level resistance differences, the dimensions of each flow channel usually satisfy the following relationship: the length of the third-level flow channel ≤ the length of the second-level flow channel ≤ the length of the first-level flow channel, the cross-sectional area of ​​the second-level flow channel and the cross-sectional area of ​​the third-level flow channel are both ≤ the cross-sectional area of ​​the first-level flow channel, and the diameter of the central main chamber is > the cross-sectional width of the third-level flow channel, the cross-sectional width of the second-level flow channel, and the cross-sectional width of the first-level flow channel, respectively.

[0020] The present invention adopts the above technical solution and has the following technical effects compared with the prior art: The detection mold of this invention adopts a radial multi-stage flow channel structure. The cross-sectional area of ​​the primary, secondary, and tertiary flow channels is gradually reduced, and the positions of the secondary and tertiary flow channels are also adjusted to increase the resistance to metal flow. This can amplify and clearly show the differences in ductility of copper ingots of different qualities. It has high discrimination and sensitivity in ductility assessment, and a single test can simultaneously assess the material's flow capacity and isotropy in multiple directions, which is closer to the actual hot working and filling scenarios of complex forgings.

[0021] The detection method of this invention can complete the ductility test in only three steps. It is simple and efficient to operate. It transforms the abstract solid ductility into measurable and statistical volume ratios and geometric data. By combining quantitative indicators such as theoretical filling degree, actual filling degree, and filling integrity with auxiliary indicators such as flow channel filling length and filling symmetry, it achieves an objective and quantitative evaluation of the high-temperature solid ductility of copper ingots. The results are intuitive and comparable.

[0022] Meanwhile, the entire testing process does not require expensive specialized equipment and can be completed using conventional heating furnaces and presses, resulting in low testing costs. It is very suitable for incoming material quality control on the production site and rapid testing in the laboratory, and can provide reliable technical support for the optimization of hot working processes for copper and copper alloys. Attached Figure Description

[0023] Figure 1 This is a top view of the upper mold assembly in this invention; Figure 2 for Figure 1 A schematic diagram of the cross-sectional structure along section AA; Figure 3 This is a side view of the upper punch die in this invention. Figure 4 This is a cross-sectional view of the lower mold assembly in this invention; Figure 5 This is a side view of the lower punch die in this invention. Figure 6 This is a top view of the formed red-stamped part in this invention. Explanation of reference numerals in the attached drawings: 1. Upper die assembly; 11. Central main chamber; 12. Primary runner; 13. Secondary runner; 14. Tertiary runner; 2. Lower die assembly; 21. Main chamber; 3. Upper punch; 4. Lower punch. Detailed Implementation

[0024] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0026] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but this is not intended to limit the scope of the invention.

[0027] Example 1 This embodiment provides a method for detecting the high-temperature solid-state ductility of copper ingots. The method converts the high-temperature solid-state ductility of copper ingots into quantifiable volumetric and measurable geometric indices, thereby enabling the evaluation of ductility. The specific operation steps are as follows: Step 1: Process the copper ingot to be tested into a cylindrical sample with a first volume, which is the volume of the cylindrical sample calculated using the cylinder volume calculation formula; Place the prepared cylindrical sample into a heating furnace and heat it to a target temperature in the range of 300℃-800℃. The preferred range of this temperature range is 450℃-780℃. The specific target temperature needs to be determined according to the actual situation. For example, the target temperature used in this embodiment is 680℃. In this embodiment, a gas-fired heating furnace is used, and the temperature control accuracy of the gas-fired heating furnace is ±15℃. After heating to the target temperature, the temperature is held for a preset time to ensure that the interior and surface of the cylindrical sample are heated evenly, thus obtaining the heated sample.

[0028] Step 2: Preheat the upper mold assembly 1 and lower mold assembly 2 of the test mold to 250℃. After preheating, close the upper mold assembly 1 and lower mold assembly 2. When closing the mold, insert the limiting protrusion on the side of the upper mold assembly 1 near the lower mold assembly 2 into the corresponding receiving groove of the lower mold assembly 2. Through the cooperation of the limiting protrusion and the receiving groove, the radial movement or offset between the upper mold assembly 1 and the lower mold assembly 2 is restricted. The step on the side of the lower mold assembly 2 near the upper mold assembly 1 directly forms the bottom surface of the first-level flow channel 12, the second-level flow channel 13, and the third-level flow channel 14 of the upper mold assembly 1, so that the upper mold assembly 1 and the lower mold assembly 2 form a complete cavity structure after closing the mold. Calculate and record the total volume of the mold cavity, and record this volume as the second volume.

[0029] Then, the heated sample from step one is quickly transferred to the central main chamber 11 of the preheated upper mold assembly 1 of the test mold. The test mold with the heated sample is then immediately placed on a press for hot stamping. In this embodiment, an 80-ton hydraulic press is used. It should be further explained that one end of the upper punch die 3 is detachably set in the central main chamber 11. During the hot punching process, it works with the press to provide vertical hot punching force, pushing the sample to flow and fill into the primary flow channel 12, secondary flow channel 13, and tertiary flow channel 14. After the hot punching reaches the predetermined stroke, the pressure is maintained for pressure holding. The pressure holding time is controlled within 3 seconds to reduce cavity shrinkage caused by the loss of pressure.

[0030] After the pressure holding is completed, the molded sample inside the mold cavity to be tested is naturally cooled to room temperature. Then, the upper punch 3 is pushed downward from the upper end of the central main chamber 11 by the press to push the hot-stamped sample out of the mold cavity of the test mold, thus obtaining the hot-stamped part. It should also be noted in the above operation steps that: one end of the lower die 4 is detachably set at the end of the main cavity 21 of the lower die assembly 2 away from the upper die assembly 1. When demolding, the upper die assembly 1 and the lower die assembly 2 are separated. Since the lower die assembly 2 is fixedly set on the bearing platform of the press during use, the lower die assembly 2 remains stationary when the upper die assembly 1 and the lower die assembly 2 are separated. The upper die assembly 1 is lifted, and then the upper die 3 is forced downward from the upper end of the central main chamber 11 by the press, pushing the hot-stamped part downward (i.e., one end of the bottom surface of the primary runner 12, secondary runner 13, and tertiary runner 14) out of the central main chamber 11, so as to achieve smooth demolding of the formed hot-stamped part.

[0031] Step 3: Remove the flash caused by the overflow of the hot stamping material on the surface of the formed hot stamping part to ensure that the measured volume of the hot stamping part is the actual volume of the cavity filled; then use the drainage method or volume measuring instrument to measure and record the actual volume of the formed hot stamping part after removing the flash, and record this volume as the third volume.

[0032] Specifically, the theoretical fill degree, actual fill degree, and fill integrity are calculated based on the first, second, and third volumes mentioned above, respectively. The specific calculation formulas are as follows: Theoretical fill factor = First volume / Second volume; Actual fill factor = third volume / second volume; Fill completeness = Actual fill degree / Theoretical fill degree; The core evaluation index is the filling integrity, and the average distance between the secondary flow channel 13 and the tertiary flow channel 14 of the formed red-stamped part is used for auxiliary evaluation. The average distance is calculated as follows: the horizontal distance from the filling end of the secondary channel 13 to the filling end of the tertiary channel 14 corresponding to each primary channel 12 is measured (e.g., ...). Figure 6 (As shown in points B-B2), sum the distances corresponding to each primary flow channel 12 and divide by the number of primary flow channels 12; at the same time, the symmetry of the filling length in each direction can be combined to comprehensively judge the high-temperature solid-state ductility of the copper ingot under test at the target temperature. Furthermore, the filling state of the formed hot stamping parts in the three-stage flow channel 14 is also divided into three categories: fully filled, partially filled, or unfilled, thereby providing a technical basis for optimizing the hot working process and controlling the quality of incoming materials.

[0033] Example 2 This embodiment provides a testing mold for the high-temperature solid-state ductility of copper ingots, implementing the testing method of Embodiment 1. The mold includes an upper mold assembly 1, a lower mold assembly 2, an upper punch 3, and a lower punch 4. The core of the lower mold assembly 2 is made of H13 hot-work die steel, and its hardness after heat treatment is HRC48-55. Among them, the upper mold assembly 1 is the core cavity component of the testing mold. The upper mold assembly 1 has a central main chamber 11 that extends along the height direction and communicates with the outside. The central main chamber 11 has a diameter of 15mm and a depth of 15mm. It is mainly used to accommodate the initial cylindrical copper ingot sample and provide the initial accommodating space for the red-hot filling of the sample. The bottom of the central main chamber 11 has four primary flow channels 12 evenly distributed along the circumference. The adjacent primary flow channels 12 form a 90° angle. The length of the primary flow channel 12 is 8.5 mm. The cross-section of the primary flow channel 12 is rectangular. The cross-sectional width of the primary flow channel 12 is 4 mm. The cross-sectional depth of the primary flow channel 12 is 5 mm. The primary flow channels 12 are connected to the central main chamber 11 and are the main channels for the sample to flow outward from the central main chamber 11.

[0034] Each primary flow channel 12 is connected to a secondary flow channel 13 and a tertiary flow channel 14. The secondary flow channel 13 starts at the connection between the central main compartment 11 and the primary flow channel 12, and the tertiary flow channel 14 starts at the middle of the length of the primary flow channel 12. The secondary flow channel 13 and the tertiary flow channel 14 are respectively located on both sides of the primary flow channel 12, and their extension directions are at a 45° angle to the extension direction of the primary flow channel 12. The secondary flow channel 13 and the tertiary flow channel 14 have the same dimensions. The cross-sections of the secondary flow channel 13 and the tertiary flow channel 14 are both rectangular. The length of the secondary flow channel 13 is 5 mm, the cross-sectional width of the secondary flow channel 13 is 2 mm, and the cross-sectional depth of the secondary flow channel 13 is 3 mm. The length of the tertiary flow channel 14 is 5 mm, the cross-sectional width of the tertiary flow channel 14 is 2 mm, and the cross-sectional depth of the tertiary flow channel 14 is 3 mm. The cross-sectional area of ​​both is smaller than that of the primary flow channel 12.

[0035] It should be further explained that the bottom surfaces of the primary flow channel 12, secondary flow channel 13, and tertiary flow channel 14 are all open; and a circular limiting protrusion is provided on the side of the upper mold assembly 1 near the lower mold assembly 2. The limiting protrusion cooperates with the receiving groove of the lower mold assembly 2 to realize the mold closing of the upper mold assembly 1 and the lower mold assembly 2, limit the radial offset between the two, and ensure the sealing and filling accuracy of the flow channels after mold closing.

[0036] The lower die assembly 2 is detachably installed at the bottom of the upper die assembly 1. The lower die assembly 2 has a main cavity 21 that is coaxial with and connected to the central main chamber 11 along the height direction. The size of the main cavity 21 matches the central main chamber 11, providing space for the installation and movement of the lower punch 4. At the same time, the main cavity 21 cooperates with the central main chamber 11 to ensure the vertical accommodation space for the copper ingot sample during the hot stamping process.

[0037] Among them, the lower mold assembly 2 has a receiving groove on the side close to the upper mold assembly 1 that is adapted to the limiting protrusion of the upper mold assembly 1. When the upper mold assembly 1 and the lower mold assembly 2 are closed, the limiting protrusion is embedded in the receiving groove to restrict the radial movement or offset between the upper mold assembly 1 and the lower mold assembly 2. It should be further explained that after the upper mold assembly 1 and the lower mold assembly 2 are closed, the upper surface of the lower mold assembly 2 serves as a sealing surface, sealing the open bottom surfaces of the primary flow channel 12, the secondary flow channel 13, and the tertiary flow channel 14, so that the test mold forms a complete and sealed cavity structure.

[0038] In this embodiment, the total cavity volume after mold closing is 3619.663 mm². 3 This refers to the second volume in the detection method.

[0039] One end of the upper punch 3 is detachably installed in the central main chamber 11 of the upper die assembly 1, and is fitted with the inner wall of the central main chamber 11 with a gap. This ensures that the upper punch 3 slides vertically in the central main chamber 11 and prevents the copper ingot sample from overflowing from the gap during the hot stamping process. The main function of the upper punch 3 is to cooperate with the press to provide the vertical pressure for hot stamping, and to push the copper ingot sample in the central main chamber 11 to flow into the primary flow channel 12, the secondary flow channel 13, and the tertiary flow channel 14. At the same time, it applies downward force to assist in the demolding of the hot stamped part during demolding.

[0040] The lower die 4 is detachably disposed at one end in the main cavity 21 of the lower die assembly 2, away from the upper die assembly 1, and is clearance-fitted with the inner wall of the main cavity 21 to ensure that the lower die 4 can slide vertically within the main cavity 21. The main function of the lower die 4 is to act as a sealing component at the bottom of the cavity: it is detachably disposed in the main cavity 21 of the lower die assembly 2, away from the upper die assembly 1, and is clearance-fitted with the inner wall of the main cavity 21. When the upper die assembly 1 and the lower die assembly 2 are closed, the upper end face of the lower die 4 and the bottom of the upper die assembly 1 work together to close the open bottom surfaces of the primary flow channel 12, the secondary flow channel 13, and the tertiary flow channel 14, so that the inspection mold forms a complete cavity structure.

[0041] In the testing mold of this embodiment, the central main chamber 11 is the initial space for the sample. The primary flow channel 12 is connected to the central main chamber 11, and the secondary flow channel 13 and the tertiary flow channel 14 are indirectly connected to the central main chamber 11 through the primary flow channel 12. Under the action of red-hot pressing pressure, the copper ingot sample flows from the central main chamber 11 to the primary flow channel 12, the secondary flow channel 13, and the tertiary flow channel 14 in sequence. The multi-level structure of the flow channels can reflect the ductility of the copper ingot under different resistances, and realize the evaluation of the high-temperature solid-state ductility of the copper ingot.

[0042] Example 3 This embodiment uses the high-temperature solid-state ductility testing method for copper ingots from Example 1 and the testing mold from Example 2 to test the high-temperature solid-state ductility of T2 pure copper at 680℃, verifying the practicality and effectiveness of the testing method and testing mold. The specific testing process, process parameters, and test results are as follows: Step 1: The material to be tested is T2 pure copper (Cu≥99.9%), which is made into a cylindrical sample with a diameter of 13mm and a height of 27mm. The first volume (ingot volume) of the cylindrical sample is calculated to be 3581.955mm³ using the cylindrical volume formula. 3 This serves as the foundational data for this test.

[0043] Step 2: Setting Process Parameters The process parameters for this test were strictly set according to the method in Example 1. Specific conditions were as follows: the heating temperature of the gas-fired furnace was 680±15℃, and the holding time for the cylindrical sample was 10 minutes to ensure uniform heating; the preheating temperature of the test mold was 250℃ to reduce temperature loss during sample transfer; an 80-ton hydraulic press was used for hot stamping in this example, with a pressure of 80 tons during hot stamping. After hot stamping to the predetermined stroke (in this example, the upper stamping mold 3 is lowered by 30mm), pressure was maintained for 3 seconds; the second volume of the cavity after mold closing was 3619.663 mm². 3 ; The specific operation process of step two is as follows: The T2 pure copper cylindrical sample, heated to 680±15℃ and kept at a uniform temperature, is quickly transferred to the central main chamber 11 of the test mold, which has been preheated to 250℃. Then, the red stamping operation is immediately performed. After the red stamping pressure is completed, it is cooled to room temperature. When demolding, the upper mold assembly 1 and the lower mold assembly 2 are separated. Since the lower mold assembly 2 is fixedly set on the bearing platform of the press during use, the lower mold assembly 2 remains stationary during the separation process, and only the upper mold assembly 1 is lifted. Then, the upper stamping die 3 is driven by the press to apply downward force from the upper end of the central main chamber 11, pushing the red-stamped finished product downward out of the central main chamber 11, so as to achieve smooth demolding of the formed red-stamped part. Then, the flash on the surface of the formed red-stamped part is removed.

[0044] Step 3: Inspection Results and Data Measurement. Volume and geometric parameters of the formed hot-stamped part after flash removal were measured, and the runner filling was observed. Specific inspection results are as follows: Quantitative indicators: The actual fill power is 94.10%, and the actual volume of the formed hot-stamped part after removing flash is 3406.103 mm². 3 According to the formula, the result is: Theoretical fill factor = First volume / Second volume = 3581.955 / 3619.663 = 98.95%; Filling completeness = Actual fill percentage / Theoretical fill percentage = 94.10% / 98.95% = 95.09%; Auxiliary indicator: The average filling distance of the formed hot-stamped part from the filling end of the secondary runner 13 to the filling end of the tertiary runner 14 corresponding to the four primary runners 12 (see [reference]). Figure 6 The horizontal distance between points B and B2 is 8.5 mm, and the filling state of the formed red stamped part in the third-level flow channel 14 is unfilled; Macroscopic observation: The outline of the formed red stamped part is clear, with no obvious flash. The four primary runners 12 are completely filled, the four secondary runners 13 are 50% filled, and the four tertiary runners 14 are not filled.

[0045] Based on the above test results and data measurement, and combined with the evaluation criteria for high-temperature solid-state ductility (filling integrity ≥95% is excellent, 90-95% is good, ≤90% is unqualified), T2 pure copper has an excellent high-temperature solid-state ductility rating at 680±15℃. It can fill the primary flow channel 12 of the mold well at this temperature, has a certain high-temperature solid-state ductility, and can meet the process requirements of conventional hot working.

[0046] Example 4 This embodiment uses the high-temperature solid-state ductility testing method for copper ingots from Example 1 and the testing mold from Example 2. Under the same process parameters as in Example 3, the high-temperature solid-state ductility of Hpb59-1 brass is tested at 680℃. The results are compared with those of T2 pure copper from Example 3 to verify the ability of the testing method and mold to distinguish the ductility of different copper materials. The specific testing process, process parameters, and test results are as follows: Step 1: Sample Preparation. The material to be tested was Hpb59-1 brass (Cu≈60.5%, balance Zn). It was processed into a cylindrical sample with the same dimensions as in Example 3, measuring 13 mm in diameter and 27 mm in height. The first volume of the sample was calculated to be 3581.955 mm³ using the cylindrical volume formula. 3 The volume is consistent with the first volume of the T2 pure copper sample in Example 3.

[0047] Step 2: The process parameters tested in this embodiment are the same as in Embodiment 3, specifically: heating temperature 680±15℃, holding time 10min, mold preheating temperature 250℃, hot stamping pressure 80 tons, holding time 3 seconds, and the second volume of the mold cavity 3619.663mm². 3 This avoids deviations in test results caused by differences in process parameters.

[0048] The post-processing steps of this embodiment, such as hot stamping, cooling demolding, and flash removal, are the same as those in Embodiment 3. The demolding operation also adopts the method of separating the upper mold assembly 1 and the lower mold assembly 2, and then applying downward force from the upper punch mold 3 to push out the formed hot stamped part, so as to ensure the consistency of the detection process in this embodiment.

[0049] Step 3: Inspection Results and Data Measurement. Volume and geometric parameters of the formed hot-stamped part after flash removal were measured, and the runner filling was observed. Specific inspection results are as follows: Quantitative indicators: The actual fill degree is 95.28%, and the actual volume of the formed red-stamped part after removing flash is 3448.715 mm³. Calculated according to the formula: Theoretical fill rate = 3581.955 / 3619.663 = 98.95%; Incomplete filling rate = 95.28% / 98.95% = 96.29%; Auxiliary indicator: The average filling distance of the formed hot-stamped part from the filling end of the secondary runner 13 to the filling end of the tertiary runner 14 corresponding to the four primary runners 12 (see [reference]). Figure 6 The horizontal distance between point B and point B2 is 9.5mm. The filling state of the formed red stamped part in the third-level flow channel 14 is partially filled. Macroscopic observation: The outline of the formed red stamped part is clear, with no obvious flash. The four primary flow channels are completely filled, the four secondary flow channels are 60% filled, and the four tertiary flow channels are 20% filled.

[0050] Based on the above test results and data measurement, and combined with the evaluation criteria for high-temperature solid-state ductility (filling integrity ≥95% is excellent, 90-95% is good, ≤90% is unqualified), Hpb59-1 brass has an excellent high-temperature solid-state ductility rating at 680±15℃. Furthermore, its filling integrity and the filling length of the formed red-stamped part in the secondary flow channel 13 are both higher than those of T2 pure copper. The formed red-stamped part is partially filled in the tertiary flow channel 14, indicating that Hpb59-1 brass has better high-temperature solid-state ductility than T2 pure copper at 680±15℃.

[0051] The test results show that the test method and test mold of this invention can clearly distinguish the differences in high-temperature solid-state ductility of different copper materials at the same temperature. The test results are intuitive and quantitative, and can provide accurate technical basis for optimizing the heat treatment process of different copper materials. At the same time, it verifies the practicality and effectiveness of the test method and test mold of this invention.

[0052] In summary, the copper ingot high-temperature solid-state ductility testing method of the present invention is simple to operate and low in cost. It does not require expensive special equipment and can be completed using conventional heating furnaces and presses. It can transform the abstract high-temperature solid-state ductility of copper ingots into quantifiable volume indicators and measurable geometric indicators, realizing an objective and quantitative assessment of ductility. The matching testing mold adopts a centrally symmetrical radial multi-stage flow channel structure. The progressively increasing flow resistance can amplify the ductility differences of different copper materials, resulting in high detection discrimination and high sensitivity, which is closer to the actual hot working and filling scenarios of complex forgings.

[0053] The upper and lower mold components of the testing mold have a reasonable flow channel structure design and are easy to disassemble and assemble. Through actual testing verification in Examples 3 and 4, the testing method and testing mold of the present invention can accurately and intuitively evaluate the high-temperature solid-state ductility of copper and copper alloys, and can clearly distinguish the ductility differences of different copper materials, providing reliable technical support for incoming material quality control and process optimization of copper and copper alloy hot working.

[0054] The above description of the present invention is merely a preferred embodiment of the present invention and does not limit the implementation and protection scope of the present invention. Those skilled in the art should realize that any equivalent substitutions and obvious changes made based on the description and illustrations of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for detecting the high-temperature solid-state ductility of copper ingots, characterized in that, Includes the following steps: Step 1: Process the copper ingot to be tested into a cylindrical sample with a first volume, heat the cylindrical sample to 300℃-800℃ and keep it at that temperature until the cylindrical sample is uniformly heated to obtain the heated sample. Step 2: Quickly transfer the heated sample into a preheated testing mold. The testing mold has a cavity with a second volume, and the heated sample is accommodated through the cavity. Then, perform a hot stamping operation on the heated sample. After holding the pressure, cool it to room temperature, and then eject the hot-stamped sample from the testing mold to obtain the formed hot-stamped part. Step 3: After removing the flash from the formed red-stamped part, measure the volume of the formed red-stamped part after flash removal, and record it as the third volume; The high-temperature solid-state ductility of the copper ingot to be tested is evaluated by the degree of filling of the heated sample in the test mold, wherein the degree of filling is the ratio of the third volume to the first volume.

2. The method for detecting the high-temperature solid-state ductility of copper ingots according to claim 1, characterized in that, In step two, the preheating temperature of the testing mold is 250℃-300℃, and the holding time after the hot stamping operation is 3s-10s.

3. The method for detecting the high-temperature solid-state ductility of copper ingots according to claim 1, characterized in that, The testing mold includes: an upper mold assembly (1) and an upper punch mold (3); The cavity of the upper mold assembly (1) includes: a central main chamber (11) arranged along its height direction and connected to the outside, a plurality of primary flow channels (12) connected to the central main chamber (11), a plurality of secondary flow channels (13) respectively connected to each of the primary flow channels (12), and a plurality of tertiary flow channels (14) respectively connected to each of the primary flow channels (12). The central main chamber (11) is located at the center of the upper die assembly (1). The primary flow channel (12), the secondary flow channel (13), and the tertiary flow channel (14) are located at the bottom of the central main chamber (11). Several primary flow channels (12) are equidistantly distributed along the circumferential direction of the central main chamber (11). The secondary flow channel (13) starts at the connection between the central main chamber (11) and the primary flow channel (12). The tertiary flow channel (14) starts at the middle of the primary flow channel (12). The secondary flow channel (13) and the tertiary flow channel (14) are respectively located on both sides of the primary flow channel (12). One end of the upper punch die (3) is detachably installed in the central main chamber (11).

4. The method for detecting the high-temperature solid-state ductility of copper ingots according to claim 3, characterized in that, The testing mold further includes: a lower mold assembly (2) detachably disposed at the bottom of the upper mold assembly (1), and a lower punch (4); The lower die assembly (2) has a main cavity (21) that is coaxial with and connected to the central main cavity (11) along its height direction. One end of the lower punch (4) is detachably disposed in the main cavity (21) at the end away from the upper die assembly (1).

5. The method for detecting the high-temperature solid-state ductility of copper ingots according to claim 3, characterized in that, The number of primary flow channels (12) is 4-8.

6. The method for detecting the high-temperature solid-state ductility of copper ingots according to claim 3, characterized in that, The extension direction of the secondary flow channel (13) forms an angle of 30°-60° with the extension direction of the primary flow channel (12), and the extension direction of the tertiary flow channel (14) forms an angle of 40°-50° with the extension direction of the primary flow channel (12).

7. The method for detecting the high-temperature solid-state ductility of copper ingots according to claim 3, characterized in that, The cross-sections of the primary flow channel (12), the secondary flow channel (13), and the tertiary flow channel (14) are all rectangular, and the cross-sectional areas of the secondary flow channel (13) and the tertiary flow channel (14) are all smaller than the cross-sectional area of ​​the primary flow channel (12).

8. The method for detecting the high-temperature solid-state ductility of copper ingots according to claim 3, characterized in that, The high-temperature solid-state ductility of the copper ingot to be tested is also evaluated by the filling length of the formed red stamping part in the secondary flow channel (13) and / or the filling state of the formed red stamping part in the tertiary flow channel (14). The filling length of the secondary flow channel (13) is the horizontal distance from the starting point of the secondary flow channel (13) to the filling end of the molded red stamping part inside the secondary flow channel (13). The filling state of the molded red stamping part in the tertiary flow channel (14) is evaluated as fully filled, partially filled or unfilled.

9. The method for detecting the high-temperature solid-state ductility of copper ingots according to claim 3, characterized in that, The diameter of the central main compartment (11) is 15mm-200mm, and the depth of the central main compartment (11) is 15mm-200mm; The length of the primary flow channel (12) is 8mm-100mm, the cross-sectional width of the primary flow channel (12) is 4mm-100mm, and the cross-sectional depth of the primary flow channel (12) is 5mm-100mm.

10. The method for detecting the high-temperature solid-state ductility of copper ingots according to claim 3, characterized in that, The length of the secondary flow channel (13) is 5mm-80mm, the cross-sectional width of the secondary flow channel (13) is 2mm-50mm, and the cross-sectional depth of the secondary flow channel (13) is 3mm-50mm. The length of the tertiary flow channel (14) is 5mm-80mm, the cross-sectional width of the tertiary flow channel (14) is 2mm-50mm, and the cross-sectional depth of the tertiary flow channel (14) is 3mm-50mm.

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