Processing technology for producing ultra-fine grain high-purity copper material

Abstract

The invention discloses a processing technology for production of an ultra-fine grain high-purity copper material, and relates to the technical field of production of ultra-fine grain high-purity copper materials, and the processing technology comprises the following specific steps: step 1, shearing cathode copper by adopting a plate shearing machine; 2, smelting processing is conducted through a vacuum smelting furnace; and thirdly, the refined copper melt obtained after vacuum melting is transferred into a heat preservation furnace, molten copper is distributed into all crystallizers through the heat preservation furnace, the molten copper is solidified and formed in the crystallizers, and a copper bar blank is obtained. The processing technology for producing the ultra-fine grain high-purity copper material is short in production period, high in efficiency and low in cost, the surface of a processed cast ingot is smooth and glossy, the internal structure is compact and free of defects, meanwhile, the defects of copper material extrusion processing at present are overcome, and therefore multi-dimensional and multi-angle extrusion operation is conducted on the copper material; therefore, the processing purity of the copper material is further improved.

Description

Technical Field

[0001] The present invention relates to the technical field of the production of ultra-fine grained high-purity copper materials, and specifically to a processing technology for the production of ultra-fine grained high-purity copper materials. Background Art

[0002] Ultra-high purity copper refers to copper with extremely high purity, and its purity can reach 99.99999% (7N) or even higher. This kind of copper not only presents a beautiful rose-gold color in terms of color, but also has significant differences from ordinary copper in terms of surface texture and physical and chemical properties. The electrical conductivity and thermal conductivity of ultra-high purity copper are both superior to those of ordinary copper, which makes it widely used in the fields of electronics, electricity, energy transmission, etc. Ultra-fine grained steel is a material with a grain size less than 100 nanometers. This extremely small grain size endows it with a series of excellent physical and mechanical properties. It is one of the essential researches to improve the production process of ultra-fine grained high-purity copper materials. Summary of the Invention

[0003] Aiming at the deficiencies of the prior art, the present invention provides a processing technology for the production of ultra-fine grained high-purity copper materials, and solves the problems put forward in the above background art.

[0004] To achieve the above objectives, the present invention is realized through the following technical solutions: A processing technology for the production of ultra-fine grained high-purity copper materials, including the following specific steps:

[0005] Step 1: Use a shearing machine to perform equidistant shearing operations on cathode copper;

[0006] Step 2: Use a vacuum melting furnace for melting processing;

[0007] Step 3: Transfer the refined copper melt after vacuum melting into a holding furnace, and distribute the copper liquid to each crystallizer through the holding furnace. The copper liquid solidifies in the crystallizer to obtain a copper rod blank;

[0008] Step 4: Use a continuous extruder to perform extrusion operations on the copper rod blank to obtain an extruded blank;

[0009] Step 5: Use a hydraulic drawing machine to draw the extruded blank to obtain a semi-finished product;

[0010] Step 6: Use a two-roll straightening machine to straighten the drawn semi-finished copper rod;

[0011] Step 7: Eliminate the stress and anneal the drawn semi-finished copper rod to obtain a high-purity copper finished product;

[0012] Step 8: Heat the ultra-high purity copper or copper alloy blank to 160 - 180 °C and hold for 30 - 45 minutes; then raise the temperature to 250 - 280 °C;

[0013] Step 9: Equal-channel angular pressing is carried out, which is divided into horizontal equal-channel angular pressing and vertical equal-channel angular pressing. One horizontal equal-channel angular pressing and one vertical equal-channel angular pressing form a complete set of pressing steps, and 2-3 sets are pressed;

[0014] Specifically as follows:

[0015] For the first equal-channel angular pressing, the inner angle range of the pressing die is 80-90°, and the outer die angle is set to 10-24°;

[0016] For the first time, the blank is pressed;

[0017] For the second time, after the blank is rotated 90° in the horizontal direction, it is pressed;

[0018] For the third time, after the blank is rotated 90° in the vertical direction, it is pressed;

[0019] The above three pressing processes are a complete set of pressing processes, and 3-5 sets are pressed;

[0020] At the end of each set of pressing operations, there is no need to return the blank to its original position;

[0021] For the second equal-channel angular pressing, the inner angle range of the pressing die is 100-120°, and the outer die angle is set to 28-38°;

[0022] For the first time, the blank is pressed;

[0023] For the second time, after the blank is rotated 90° in the horizontal direction, it is pressed;

[0024] For the third time, after the blank is rotated 90° in the vertical direction, it is pressed;

[0025] The above three pressing processes are a complete set of pressing processes, and 3-5 sets are pressed;

[0026] At the end of each set of pressing operations, there is no need to return the blank to its original position;

[0027] Step 10: Through equal-channel angular pressing, the grains are effectively refined; the grains are refined to less than 5 μm;

[0028] Step 11: After the pressing and grain refinement are completed, subsequent processing is carried out to obtain ultrafine-grained high-purity copper material.

[0029] Optionally, the melting and processing in Step 2 are specifically as follows:

[0030] (1) Vacuum is pumped to a vacuum degree of ≤1-3.5 Pa, and the melt is solidified through a cooling operation to fully remove gas, and a copper solid is obtained;

[0031] (2) The copper solid is refined;

[0032] (3) Heat it up to 850 - 950 °C at a heating rate of 10 - 18 °C / h and hold for 20 - 40 min;

[0033] (4) Heat it up to 1150 - 1250 °C at a heating rate of 40 - 60 °C / h and hold for 150 - 180 min;

[0034] (5) Heat it up to 1350 - 1400 °C at a heating rate of 10 - 15 °C / h and hold for 30 - 45 min,

[0035] (6) Obtain the refined copper melt.

[0036] Optionally, in step (2), the refining is carried out by heating at a heating rate of 10 - 15 °C / h to 600 - 850 °C.

[0037] Optionally, in step four, the extrusion temperature of the extruder is 700 - 850 °C, the extrusion pressure is 20 - 45 MN, and the thickness of the butt is controlled at 10 - 40 mm.

[0038] Optionally, in step seven, the annealing temperature is 350 - 450 °C and the holding time is 4 - 10 h.

[0039] Optionally, the subsequent treatment in step eleven includes natural cooling and surface cleaning operation of the copper material.

[0040] The present invention provides a processing technology for the production of ultrafine-grained high-purity copper materials, having the following beneficial effects:

[0041] This processing technology for the production of ultrafine-grained high-purity copper materials has a short production cycle, high efficiency, and low cost. The surface of the processed ingot is flat and shiny, and the internal structure is dense and defect-free. At the same time, it improves the current defects in the extrusion processing of copper materials, thereby performing multi-dimensional and multi-angle extrusion operations on the copper materials, further improving the purity of the copper material processing. Specific embodiments

[0042] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments.

[0043] Embodiment 1: A processing technology for the production of ultrafine-grained high-purity copper materials, including the following specific steps:

[0044] Step 1: Use a shearing machine to perform equidistant shearing operations on cathode copper;

[0045] Step 2: Use a vacuum melting furnace for melting processing, specifically as follows:

[0046] (1) Evacuate to a vacuum degree of ≤2.5 Pa, and solidify the melt through cooling operation to fully degas and obtain a copper solidified body;

[0047] (2) Refine the copper solidified body, and raise the temperature to 785.2 °C at a heating rate of 12.3 °C / h;

[0048] (3) Raise the temperature to 928.8 °C at a heating rate of 15 °C / h and hold for 30 min;

[0049] (4) Raise the temperature to 1121.1 °C at a heating rate of 58 °C / h and hold for 180 min;

[0050] (5) Raise the temperature to 1392 °C at a heating rate of 10 °C / h and hold for 35 min;

[0051] (6) Obtain a refined copper melt;

[0052] Step 3: Transfer the refined copper melt after vacuum melting to a holding furnace, distribute the copper liquid to each crystallizer through the holding furnace, and the copper liquid solidifies in the crystallizer to obtain a copper rod blank;

[0053] Step 4: Perform extrusion operation on the copper rod blank using a continuous extruder to obtain an extrusion blank. The extrusion temperature of the extruder is 762 °C, the extrusion pressure is 38 MN, and the thickness of the butt is controlled at 25 mm;

[0054] Step 5: Stretch the extrusion blank using a hydraulic drawing machine to obtain a semi-finished product;

[0055] Step 6: Perform straightening operation on the stretched semi-finished copper rod using a two-roll straightening machine;

[0056] Step 7: Eliminate stress and anneal the stretched semi-finished copper rod. The annealing temperature is 420 °C and the holding time is 6.5 h to obtain a high-purity copper finished product;

[0057] Step 8: Heat the ultra-high purity copper or copper alloy blank to 175 °C and hold for 30 min; then raise the temperature to 268 °C;

[0058] Step 9: Perform equal-channel angular pressing, which is divided into horizontal equal-channel angular pressing and vertical equal-channel angular pressing. One horizontal equal-channel angular pressing and one vertical equal-channel angular pressing are a set of complete pressing steps, and press 3 groups;

[0059] Specifically as follows:

[0060] The first equal-channel angular pressing, the inner angle range of the pressing die is 80 - 90°, and the outer die angle is set to 10 - 24°;

[0061] For the first time, press the blank;

[0062] Second, after the blank is rotated 90° in the horizontal direction, it is extruded;

[0063] Third, after the blank is rotated 90° in the vertical direction, it is extruded;

[0064] The above three extrusion processes are a set of complete extrusion processes, and 4 sets are extruded;

[0065] At the end of each set of extrusion operations, there is no need to return the blank to its original position;

[0066] For the second equal-channel angular extrusion, the inner angle range of the extrusion die is 100 - 120°, and the outer die angle is set to 28 - 38°;

[0067] First, extrude the blank;

[0068] Second, after the blank is rotated 90° in the horizontal direction, it is extruded;

[0069] Third, after the blank is rotated 90° in the vertical direction, it is extruded;

[0070] The above three extrusion processes are a set of complete extrusion processes, and 4 sets are extruded;

[0071] At the end of each set of extrusion operations, there is no need to return the blank to its original position;

[0072] Step ten: Through equal-channel angular extrusion, the grains are effectively refined; the grains are refined to less than 4 μm;

[0073] Step eleven: After extrusion and grain refinement are completed, follow-up processing is carried out to obtain ultra-fine-grained high-purity copper. The follow-up processing includes natural cooling and surface cleaning operations of the copper.

[0074] Example two: A processing technology for the production of ultra-fine-grained high-purity copper includes the following specific steps:

[0075] Step one: Use a shearing machine to perform equidistant shearing operations on cathode copper;

[0076] Step two: Use a vacuum melting furnace for melting processing, specifically as follows:

[0077] (1) Evacuate to a vacuum degree ≤ 3.5 Pa, and solidify the melt through temperature reduction operations to fully remove gas and obtain a copper solid;

[0078] (2) Refine the copper solid. The refining is carried out by heating at a heating rate of 13.9 °C / h to 835.0 °C;

[0079] (3) Heat at a heating rate of 15 °C / h to 895.2 °C and hold for 30 min;

[0080] (4) Heat at a heating rate of 40 °C / h to 1201.0 °C and hold for 150 min;

[0081] (5) Heat at a heating rate of 12 °C / h to 1386.7 °C and hold for 30 min;

[0082] (6) Obtain the refined copper melt;

[0083] Step Three: Transfer the refined copper melt after vacuum melting to the holding furnace, distribute the copper liquid to each crystallizer through the holding furnace, and let the copper liquid solidify in the crystallizer to obtain the copper rod blank;

[0084] Step Four: Extrude the copper rod blank using a continuous extruder to obtain the extruded blank. The extrusion temperature of the extruder is 795.8 °C, the extrusion pressure is 30 MN, and the thickness of the upset is controlled at 25 mm;

[0085] Step Five: Stretch the extruded blank using a hydraulic drawing machine to obtain the semi-finished product;

[0086] Step Six: Straighten the stretched semi-finished copper rod using a two-roll straightening machine;

[0087] Step Seven: Eliminate stress and anneal the stretched semi-finished copper rod. The annealing temperature is 360 °C and the holding time is 8 h to obtain the high-purity copper finished product;

[0088] Step Eight: Heat the ultra-high-purity copper or copper alloy blank to 160 °C and hold for 45 min; then heat to 280 °C;

[0089] Step Nine: Perform equal-channel angular pressing, which is divided into horizontal equal-channel angular pressing and vertical equal-channel angular pressing. One-time horizontal equal-channel angular pressing and one-time vertical equal-channel angular pressing are a set of complete pressing steps, and press 2 sets;

[0090] Specifically as follows:

[0091] The first equal-channel angular pressing, the inner angle range of the pressing die is 80 - 90°, and the outer die angle is set to 10 - 24°;

[0092] First time, press the blank;

[0093] Second time, after the blank rotates 90° in the horizontal direction, press;

[0094] Third time, after the blank rotates 90° in the vertical direction, press;

[0095] The above three pressing processes are a set of complete pressing processes, and press 3 sets;

[0096] At the end of each set of pressing operations, there is no need to return the blank to its original position;

[0097] The second equal-channel angular pressing, the inner angle range of the pressing die is 100 - 120°, and the outer die angle is set to 28 - 38°;

[0098] First, extrude the blank.

[0099] Second, after the blank rotates 90° in the horizontal direction, extrude it.

[0100] Third, after the blank rotates 90° in the vertical direction, extrude it.

[0101] The above three extrusion processes are a set of complete extrusion processes, and extrude 3 sets.

[0102] At the end of each set of extrusion operations, there is no need to return the blank to its original position.

[0103] Step ten: Through equal-channel angular pressing, effectively refine the grains; refine the grains to less than 5μm.

[0104] Step eleven: After completing the extrusion and grain refinement, perform subsequent processing to obtain ultrafine-grained high-purity copper. The subsequent processing includes natural cooling and surface cleaning operations of the copper.

[0105] Comparative example: A processing technology for the production of ultrafine-grained high-purity copper includes the following specific steps:

[0106] Step one: Use a shearing machine to perform equidistant shearing operations on cathode copper.

[0107] Step two: Use a vacuum melting furnace for melting processing, specifically as follows:

[0108] (1) Pump the vacuum to a vacuum degree ≤ 2.5 Pa, and solidify the melt through temperature reduction operations to fully remove gas and obtain a copper solid.

[0109] (2) Refine the copper solid. The refining is carried out by heating at a heating rate of 25°C / h to 960°C.

[0110] (3) Heat at a heating rate of 50°C / h to 1300°C and hold for heat preservation.

[0111] (4) Obtain a refined copper melt.

[0112] Step three: Transfer the refined copper melt after vacuum melting to a holding furnace, and distribute the copper liquid to each mold through the holding furnace. The copper liquid solidifies and forms in the mold to obtain a copper rod blank.

[0113] Step four: Use a continuous extruder to perform extrusion operations on the copper rod blank to obtain an extruded blank. The extrusion temperature of the extruder is 600°C, the extrusion pressure is 20 MN, and the thickness of the residue is controlled at 20 mm.

[0114] Step Five: Stretch the extruded billet with a hydraulic drawing machine to obtain a semi-finished product;

[0115] Step Six: Straighten the semi-finished copper rod after stretching with a two-roll straightening machine;

[0116] Step Seven: Eliminate stress and anneal the semi-finished copper rod after stretching. The annealing temperature is 400 °C and the holding time is 4 h to obtain a high-purity copper product;

[0117] Step Eight: Heat the ultra-high-purity copper or copper alloy billet to 160 °C and hold for 30 min; then raise the temperature to 250 °C;

[0118] Step Nine: Perform equal-channel angular pressing as follows:

[0119] The first equal-channel angular pressing, the inner angle range of the extrusion die is 82.9°, and the outer die angle is set to 21.3°; the number of extrusion passes is 4 times; after each extrusion, the billet is rotated 180° and then the next extrusion pass is carried out;

[0120] The second equal-channel angular pressing, the inner angle range of the extrusion die is 108.5°, and the outer die angle is set to 38°, the number of extrusion passes is 4 times, and after each extrusion, the billet is rotated 180° and then the next extrusion pass is carried out;

[0121] Step Ten: After completing the extrusion, clean the surface of the copper material to obtain an ultra-fine grain high-purity copper material.

[0122] 500 kg of copper material 800 kg of copper material 1000 kg of copper material Example 1 99.99999％ 99.99999％ 99.99999％ Example 2 99.99999％ 99.99999％ 99.99999％ Comparative example 99.99981％ 99.99979％ 99.99975％

[0123] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution of the present invention and its inventive concept, makes equivalent substitutions or changes, and should be covered by the protection scope of the present invention.

Claims

1. A processing technology for producing ultrafine grain high purity copper material, characterized in that: The specific steps include: Step 1: Use a shearing machine to perform equidistant shearing operation on the cathode copper; Step 2: Use a vacuum melting furnace for melting processing; Step 3: Transfer the refined copper melt after vacuum smelting to a holding furnace, distribute the copper liquid to each crystallizer through the holding furnace, and solidify the copper liquid in the crystallizer to obtain a copper rod blank; Step 4: Extruding the copper rod blank using a continuous extruder to obtain an extruded blank; Step 5: Use a hydraulic drawing machine to stretch the extruded billet to obtain a semi-finished product; Step 6: Use a two-roller straightening machine to straighten the stretched semi-finished copper rod; Step 7: Relieve stress and anneal the stretched semi-finished copper rod to obtain a high-purity copper product; Step 8: Heat the ultra-high purity copper or copper alloy billet to 160-180°C, keep warm for 30-45 minutes; then raise the temperature to 250-280°C; Step nine: perform equal-diameter angular extrusion, which is divided into horizontal equal-diameter angular extrusion and vertical equal-diameter angular extrusion, wherein one horizontal equal-diameter angular extrusion and one vertical equal-diameter angular extrusion constitute a complete set of extrusion steps, and 2-3 sets of extrusion are performed; The details are as follows: In the first equal-diameter angular extrusion, the inner angle of the extrusion die ranges from 80 to 90°, and the outer die angle is set at 10 to 24°; In the first step, the billet is extruded; The second time, the billet is rotated 90° in the horizontal direction and then extruded; The third time, the billet is rotated 90° in the vertical direction and then extruded; The above three extrusion processes constitute a complete extrusion process, extruding 3-5 groups; At the end of each set of extrusion operations, there is no need to return the billet to its original position; In the second equal diameter angular extrusion, the inner angle of the extrusion die is in the range of 100-120°, and the outer die angle is set at 28-38°; In the first step, the billet is extruded; The second time, the billet is rotated 90° in the horizontal direction and then extruded; The third time, the billet is rotated 90° in the vertical direction and then extruded; The above three extrusion processes constitute a complete extrusion process, extruding 3-5 groups; At the end of each set of extrusion operations, there is no need to return the billet to its original position; Step 10: Effectively refine the grains through equal-diameter angular extrusion; refine the grains to less than 5μm; Step 11: After extrusion and grain refinement, subsequent processing is performed to obtain ultrafine grain high-purity copper material.

2. A processing technology for producing ultrafine grain high purity copper material according to claim 1, characterized in that: The smelting process in step 2 is specifically as follows: (1) evacuating the melt to a vacuum degree of ≤1-3.5 Pa, solidifying the melt by cooling the melt to fully degas, and obtaining a copper solid; (2) refining the copper solid; (3) Heating to 850-950°C at a heating rate of 10-18°C / h and keeping at that temperature for 20-40 min; (4) Heating the temperature to 1150-1250°C at a heating rate of 40-60°C / h and keeping the temperature for 150-180 min; (5) Raise the temperature to 1350-1400℃ at a heating rate of 10-15℃ / h and keep warm for 30-45min. (6) Obtaining refined copper melt.

3. A processing technology for producing ultrafine grain high purity copper material according to claim 2, characterized in that: The refining in step (2) is carried out by heating the temperature to 600-850°C at a heating rate of 10-15°C / h.

4. The processing technology for producing ultrafine grain high purity copper material according to claim 1, characterized in that: In the step 4, the extrusion temperature of the extruder is 700-850° C., the extrusion force is 20-45 MN, and the residual thickness is controlled at 10-40 mm.

5. The processing technology for producing ultrafine grain high purity copper material according to claim 1, characterized in that: The annealing temperature in step seven is 350-450° C., and the insulation time is 4-10 hours.

6. A processing technology for producing ultrafine grain high purity copper material according to claim 1, characterized in that: The subsequent treatment in step 11 includes natural cooling and copper material surface cleaning operations.