A large-size high-tin copper alloy ingot with high plasticity and superior cold rolling performance and a preparation method thereof

Abstract

The application discloses a large-size high-tin copper alloy ingot with high plasticity and superior cold rolling performance and a preparation method thereof, and belongs to the technical field of alloy materials. The high-tin copper alloy is subjected to rapid quenching treatment and homogenization treatment after being smelted, high-quality semi-solid metal slurry is prepared, the high-quality semi-solid metal slurry is injected into a mold, and secondary quenching and extrusion are carried out, so that the generation of dendritic crystals in the structure is further prevented by using the mold wall secondary quenching nucleation process technology, the structure and mechanical properties of the alloy ingot are improved, and finally the large-size high-tin copper alloy ingot with high plasticity and superior cold rolling performance is obtained. The preparation method provided by the application completely eliminates the brittle delta phase in the alloy, eliminates the subsequent high-temperature long-time heat treatment step, realizes a short process and low cost, improves the production efficiency, and achieves the purpose of energy saving and emission reduction.

Description

Technical Field

[0001] This invention belongs to the field of alloy materials technology, and in particular relates to a large-size high-tin copper alloy ingot with both high plasticity and superior cold rolling performance and its preparation method. Background Technology

[0002] High-tin copper alloys are widely used in high-speed rail, shipbuilding, and aerospace due to their excellent mechanical properties. However, directly producing large-diameter, high-ductility high-tin copper alloy ingots without brittle δ-phase using casting processes faces several challenges, mainly in the following aspects: 1. Formation of brittle δ-phase: In copper-tin alloys, when the tin content reaches or exceeds 10 wt.%, a brittle δ-phase is easily formed. This brittle phase becomes the initiation and propagation source of cracks during plastic deformation, rendering the material unusable in subsequent processing and strengthening processes such as rolling, forging, and drawing. 2. Limitations of forming processes: Current high-ductility high-tin copper alloy ingot forming processes mostly employ a combination of casting and annealing. Although homogenization treatment can eliminate the brittle δ-phase, it also leads to an increase in alloy grain size. In addition, high-temperature, long-duration annealing significantly increases production energy consumption and time, resulting in the problems of complex process flow, long production cycle, high cost, and coarse ingot structure associated with traditional methods.

[0003] Currently, no research reports have directly obtained large-size, non-brittle δ-phase, and high-plasticity, superior cold-rolling properties high-tin-copper alloy ingots through casting. Therefore, there is an urgent need to develop a production method for large-diameter high-tin-copper alloy ingots that combines high plasticity and superior cold-rolling properties with a short process flow, short production cycle, and low cost, in order to meet the demand for high-strength, high-plasticity, large-diameter high-tin-copper alloy ingots in the defense, military, and aerospace industries. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention proposes a large-size high-tin copper alloy ingot with both high plasticity and superior cold-rolling performance, and its preparation method.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] This invention provides a method for preparing large-size high-tin copper alloy ingots that combine high plasticity and superior cold-rolling performance, comprising the following steps:

[0007] (1) Melt the high-tin copper alloy and then subject it to rapid quenching to obtain a semi-solid metal slurry;

[0008] (2) The semi-solid metal slurry obtained in step (1) is homogenized to obtain a high-quality semi-solid metal slurry.

[0009] (3) The high-quality semi-solid metal slurry obtained in step (2) is injected into the mold, and after secondary cooling and extrusion, the large-size high-tin copper alloy ingot with high plasticity and superior cold rolling performance is obtained.

[0010] This invention prepares a semi-solid metal slurry through rapid quenching. On one hand, rapid quenching induces the formation of numerous crystal nuclei during the solidification of the high-tin-copper alloy liquid; on the other hand, the rapidly flowing molten metal effectively breaks up dendrites during growth, thereby significantly increasing the number of crystal nuclei in the melt during solidification and effectively inhibiting the mutual engulfment and growth of nuclei. This process refines the grains, significantly reducing quality defects such as cracks, shrinkage cavities, porosity, and gas bubbles in the high-tin-copper alloy ingot, enabling the material to remain crack-free during high-plasticity cold rolling deformation. The high-quality semi-solid metal slurry is then injected into a mold, undergoing secondary quenching and extrusion. Utilizing the secondary quenching nucleation technology on the mold wall, the formation of dendrites in the microstructure is further prevented, improving the microstructure and mechanical properties of the alloy ingot. Ultimately, large-size high-tin-copper alloy ingots with both high plasticity and superior cold-rolling performance are obtained.

[0011] Preferably, in step (1), the melting temperature is 1100-1190℃ and the melting holding time is 5-9 min.

[0012] Preferably, in step (1), the cooling rate of the rapid quenching treatment is 400-450°C / s.

[0013] Preferably, in step (2), the temperature of the homogenization treatment is 990-1000℃, and the holding time of the homogenization treatment is 10-30s.

[0014] Preferably, in step (3), the diameter of the mold is 80-100 mm and the depth of the mold is 350-400 mm.

[0015] Preferably, in step (3), the cooling rate of the secondary quench is 300-350°C / s.

[0016] Preferably, in step (3), the extrusion temperature is 520-550°C, the extrusion forming pressure is 145-175 MPa, and the extrusion holding time is 2-3 min.

[0017] Preferably, in step (1), the smelting process further includes slag removal and settling steps.

[0018] Preferably, the temperature of the molten metal after settling is 1085–1095°C.

[0019] The present invention also provides a large-size high-tin copper alloy ingot with both high plasticity and superior cold rolling performance prepared by the preparation method described in the above technical solution.

[0020] Compared with the prior art, the present invention has the following advantages and technical effects:

[0021] This invention produces a high-quality semi-solid metal slurry by rapidly quenching and homogenizing a high-tin copper alloy after smelting. The high-quality semi-solid metal slurry is then injected into a mold and subjected to secondary quenching and extrusion. The secondary quenching nucleation process using the mold wall further prevents the formation of dendrites in the microstructure, improves the microstructure and mechanical properties of the alloy ingot, and ultimately yields a large-size high-tin copper alloy ingot with both high plasticity and superior cold rolling performance.

[0022] The preparation method provided by this invention completely eliminates the brittle δ phase in the alloy, eliminates the need for subsequent high-temperature and long-term heat treatment, and achieves a short process and low cost. This not only improves production efficiency but also achieves the goal of energy conservation and emission reduction. Attached Figure Description

[0023] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0024] Figure 1 This is a schematic diagram of the semi-solid device in step (1) of Example 1;

[0025] Figure 2 This is a schematic diagram of the extrusion process in step (2) of Example 1;

[0026] Figure 3 Microstructure images of CuSn10P1 alloy ingots prepared in Comparative Example 3 and Example 1, where (a1)-(a3) are Comparative Example 3 and (b1)-(b3) are Example 1;

[0027] Figure 4 XRD patterns of CuSn10P1 alloy ingots prepared in Comparative Example 3 and Example 1;

[0028] Figure 5 Tensile fracture surface and fracture cross section of CuSn10P1 alloy ingots prepared in Comparative Example 3 and Example 1, wherein (a1)-(a2) are Comparative Example 3, and (b1)-(b2) are Example 3;

[0029] Figure 6 The images show the actual CuSn10P1 alloy ingots prepared in Comparative Example 3 and Example 1 after cold rolling.

[0030] Figure 7 The engineering stress-strain curves of CuSn10P1 alloy ingots prepared in Example 1 with different cold rolling reductions;

[0031] Figure 8 Tensile fracture diagrams of CuSn10P1 alloy ingots prepared in Example 1 with different reductions during cold rolling, where (a) is 0% reduction, (b) is 20% reduction, (c) is 40% reduction, (d) is 60% reduction, and (e) is 80% reduction.

[0032] Figure 9 The image shows the microstructure of the CuSn10P1 alloy ingot prepared in Comparative Example 7, where (a2) is an enlarged view of (a1) and (a3) ​​is a Sn and P distribution diagram of (a2). Detailed Implementation

[0033] 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.

[0034] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0035] This invention provides a method for preparing large-size high-tin copper alloy ingots that combine high plasticity and superior cold-rolling performance, comprising the following steps:

[0036] (1) Melt the high-tin copper alloy and then subject it to rapid quenching to obtain a semi-solid metal slurry;

[0037] (2) The semi-solid metal slurry obtained in step (1) is homogenized to obtain a high-quality semi-solid metal slurry.

[0038] (3) The high-quality semi-solid metal slurry obtained in step (2) is injected into the mold, and after secondary cooling and extrusion, the large-size high-tin copper alloy ingot with high plasticity and superior cold rolling performance is obtained.

[0039] In a preferred embodiment, in step (1), the high-tin copper alloy is designated as CuSn10P1; by mass percentage, the composition of CuSn10P1 is: tin (Sn) 9.0-11.5%, phosphorus (P) 0.8-1.1%, impurities ≤0.75%, and the balance is copper (Cu).

[0040] In a preferred embodiment, in step (1), the melting temperature is 1100-1190℃, preferably 1130-1170℃; the melting holding time is 5-9 minutes; and the melting heating equipment is a medium-frequency furnace.

[0041] In a preferred embodiment, step (1) further includes slag removal and settling steps after smelting.

[0042] In a preferred embodiment, the temperature of the molten metal after settling is 1085–1095°C.

[0043] In a preferred embodiment, in step (1), the cooling rate of the rapid quenching treatment is 400–450 °C / s, preferably 420–440 °C / s. This invention controls the cooling rate of the rapid quenching treatment within the above range, which is beneficial for obtaining high-tin copper alloy ingots that possess both high plasticity and superior cold-rolling performance. Cooling rates that are too fast or too slow will reduce the plasticity and cold-rolling performance of the alloy ingot.

[0044] In a preferred embodiment, the equipment used for the rapid quenching process in step (1) is a semi-solid device. The present invention employs a semi-solid device to prepare a semi-solid metal slurry through rapid quenching, which has the following advantages: on the one hand, rapid quenching promotes the formation of a large number of crystal nuclei during the solidification of the high-tin-copper alloy liquid; on the other hand, the rapidly flowing metal liquid effectively breaks up the dendrites during the growth process, thereby significantly increasing the number of crystal nuclei in the melt during solidification and effectively inhibiting the mutual engulfment and growth of crystal nuclei. This process refines the grains, significantly reducing quality defects such as cracks, shrinkage cavities, porosity, and gas bubbles in the high-tin-copper alloy ingot, enabling the material to remain crack-free during large plastic cold rolling deformation.

[0045] In a preferred embodiment, in step (2), the temperature of the homogenization treatment is 990-1000℃, and the holding time of the homogenization treatment is 10-30s.

[0046] In a preferred embodiment, in step (3), the injection speed of injecting the high-quality semi-solid metal slurry into the mold is 80-140 cm. 3 / s, preferably 100-110cm 3 / s; The injection method is injection along the mold wall.

[0047] In a preferred embodiment, in step (3), the diameter of the mold is 80-100 mm, preferably 80-90 mm; the depth of the mold is 350-400 mm, preferably 360-380 mm. This invention uses a large-diameter, high-depth mold to prepare high-tin-copper alloy ingots. On the one hand, this achieves large-size preparation of high-tin-copper alloy ingots; on the other hand, it ensures that the molten metal can effectively contact the mold wall when it reaches the bottom of the mold, achieving the purpose of secondary cooling. This further guarantees the plasticity and cold rolling performance of large-size high-tin-copper alloy ingots, effectively solving the technical problem of traditional ingots being small in size and unable to be processed into large products.

[0048] In a preferred embodiment, in step (3), the cooling rate of the secondary quenching is 300–350 °C / s, preferably 320–340 °C / s. By controlling the cooling rate of the secondary quenching within the above range, this invention facilitates the production of high-tin-copper alloy ingots that possess both high plasticity and superior cold-rolling performance. Cooling rates that are too fast or too slow will reduce the plasticity and cold-rolling performance of the alloy ingot.

[0049] In a preferred embodiment, in step (3), the extrusion temperature is 520–550°C, preferably 530–550°C. This invention, by extruding within the above temperature range, can eliminate the brittle δ phase in the alloy, ensuring the plasticity and cold rolling performance of the alloy ingot. Excessively low or high temperatures will prevent the production of large-size high-tin copper alloy ingots that possess both high plasticity and superior cold rolling performance.

[0050] In a preferred embodiment, in step (3), the forming pressure of the extrusion is 145-175 MPa, preferably 145-155 MPa. In this invention, an excessively low forming pressure will cause a decrease in the density of the ingot, resulting in shrinkage cavities and ultimately leading to cold rolling cracking of the alloy ingot. Conversely, an excessively high forming pressure will cause semi-solid metal slurry to seep out from the edge of the mold, affecting the alloy composition.

[0051] In a preferred embodiment, the holding time for extrusion in step (3) is 2-3 minutes. If the holding time for extrusion in this invention is too short, the ingot will not be fully solidified, resulting in microcracks, which deteriorates the mechanical properties of the alloy ingot and makes it prone to cracking during cold rolling.

[0052] In a preferred embodiment, in step (3), the running speed of the extrusion punch is 21 mm / min, the holding time is 15 s, and the cooling method after extrusion is air cooling.

[0053] In a preferred embodiment, in step (3), the heating process of the extrusion is as follows: the mold used for extrusion is punched, and then a metal heating rod with a diameter of Φ of 10mm and a length of 100mm is inserted for heating; when the mold temperature reaches the extrusion temperature, it is kept warm for more than 1 hour to ensure that the temperature inside the mold is uniform, and then the extrusion begins.

[0054] The present invention also provides a large-size high-tin copper alloy ingot with both high plasticity and superior cold rolling performance prepared by the preparation method described in the above technical solution.

[0055] In this embodiment of the invention, room temperature refers to "25±2℃".

[0056] In the following examples, the chemical composition of the CuSn10P1 alloy used, by mass percentage (Wt%), is: 9.56% tin (Sn), 0.97% phosphorus (P), 0.08 wt% impurities, and the balance is copper (Cu).

[0057] Unless otherwise specified, all raw materials used in the embodiments of this invention were purchased through commercial channels.

[0058] Example 1 and Comparative Examples 1-3

[0059] A method for preparing large-size high-tin copper alloy ingots with both high plasticity and superior cold-rolling properties:

[0060] (1) Cut 4.6 kg of CuSn10P1 alloy and put it into a crucible. Then place the crucible in a medium frequency furnace and melt it at 1150℃. After the alloy is completely melted, continue to hold it at 9 min to obtain molten metal. Remove the slag from the molten metal and let it stand to cool down. When the temperature drops to 1085℃, quickly pour the molten metal into a semi-solid device for rapid quenching. At the same time, use a crucible heated to 995℃ to receive the semi-solid metal slurry flowing out of the semi-solid device. After homogenization treatment at 995℃ for 15 s, a high-quality semi-solid metal slurry is obtained. The cooling rate of the rapid quenching treatment is 420℃ / s.

[0061] (2) The high-quality semi-solid metal slurry obtained in step (1) is mixed at 100cm... 3 The material is injected into a mold with a diameter of 80 mm and a depth of 350 mm at a speed of / s for secondary cooling and extrusion. The cooling rate of the secondary cooling is 330℃ / s. Before heating the mold, a high-temperature release agent of Meishu 605 is sprayed on it. After drilling holes in the mold, a metal heating rod with a diameter of Φ of 10 mm and a length of 100 mm is inserted for heating. When the mold temperature reaches the set extrusion temperature, it is held for 1 hour, and then extrusion begins. The extrusion temperature is set as follows: 410℃ (Comparative Example 1), 450℃ (Comparative Example 2), 490℃ (Comparative Example 3), and 530℃ (Example 1). The extrusion process parameters are: punch pressure (forming specific pressure) 145MPa, punch running speed 21mm / min, holding time 15s. After holding, the ingot is left to stand in the mold for 2 minutes, and then air-cooled to room temperature to obtain a CuSn10P1 alloy ingot with a diameter of 80 mm.

[0062] Figure 1 This is a schematic diagram of the semi-solid device in step (1) of Example 1.

[0063] Figure 2 This is a schematic diagram of the extrusion process in step (2) of Example 1. Figure 2 As can be seen, this invention injects high-quality semi-solid metal slurry along the mold wall, achieving secondary cooling.

[0064] Figure 3Microstructure images of CuSn10P1 alloy ingots prepared in Comparative Example 3 and Example 1, where (a1)-(a3) are Comparative Example 3, and (b1)-(b3) are Example 1. Figure 3 As can be seen from sections (a1)-(a3), a brittle δ phase (indicated by the yellow arrow) can be clearly observed in the CuSn10P1 alloy ingot prepared in Comparative Example 1. Figure 3 No brittle δ phase was observed in the (b1)-(b3) section, and the phase indicated by the black arrow is the Cu3P phase.

[0065] Figure 4 XRD patterns of CuSn10P1 alloy ingots prepared for Comparative Example 3 and Example 1. Figure 4 Further evidence shows that the CuSn10P1 alloy ingot prepared in Example 1 does not contain the brittle δ phase, indicating that the brittle δ phase has been eliminated at an extrusion temperature of 530°C.

[0066] Performance testing:

[0067] Tensile test: The CuSn10P1 alloy ingots prepared in Example 1 and Comparative Examples 1-3 were made into test samples with a thickness of 2 mm, a width of 4 mm, and a length of 12 mm within the gauge length. The tensile rate was set to 1 mm / min for tensile testing.

[0068] Cold rolling experiment: The CuSn10P1 alloy ingots prepared in Example 1 and Comparative Examples 1-3 were made into test samples with a length of 20 mm, a width of 15 mm, and a height of 15 mm. The rolling mill roll diameter was set to 200 mm, and the roll speed was 3 r / min. At room temperature, the reduction in each rolling pass was 5%. Rolling was stopped when the sample cracked; otherwise, rolling was continued until the reduction reached 80%.

[0069] The tensile strength and cold rolling properties of the CuSn10P1 alloy ingots prepared in Examples 1 and Comparative Examples 1-3 are shown in Table 1.

[0070] Table 1. Tensile strength and cold rolling properties of CuSn10P1 alloy ingots prepared in Example 1 and Comparative Examples 1-3

[0071]

[0072] As can be seen from Table 1, with the increase of extrusion temperature, the elongation of the alloy ingot increases significantly, while the tensile strength decreases slightly after the temperature increases.

[0073] Figure 5Tensile fracture surfaces and cross-sectional views of CuSn10P1 alloy ingots prepared in Comparative Example 3 and Example 1 are shown, where (a1) is the tensile fracture surface of Comparative Example 3, (b1) is the tensile fracture surface of Example 1, (a2) is the cross-sectional view of the fracture surface of Comparative Example 3, and (b2) is the cross-sectional view of the fracture surface of Example 1. Figure 5 As can be seen, the fracture mode of the CuSn10P1 alloy ingot prepared in Comparative Example 3 is intergranular fracture, while the fracture mode of the CuSn10P1 alloy ingot prepared in Example 1 is transgranular ductile fracture, and there are a large number of dimples on the fracture surface, which further proves that eliminating the δ phase is the key to improving the plasticity of the ingot.

[0074] Figure 6 The images show the actual CuSn10P1 alloy ingots prepared in Comparative Example 3 and Example 1 after cold rolling. Figure 6 It can be seen that the CuSn10P1 alloy ingot prepared in Comparative Example 3 cracked on the surface when cold-rolled to a reduction of 50%, while the CuSn10P1 alloy ingot prepared in Example 1 did not crack on the surface when cold-rolled to a reduction of 80%.

[0075] Mechanical properties were tested during the cold rolling experiment of the CuSn10P1 alloy ingot prepared in Example 1, after being cold rolled to different reductions (0%, 20%, 40%, 60%, 80%). The test results are shown in Table 2 and [Table data missing]. Figure 7 .

[0076] Table 2 Mechanical properties of CuSn10P1 alloy ingots prepared in Example 1 after cold rolling to different reductions

[0077] Pressure reduction (%) Yield strength (MPa) Tensile strength (MPa) Elongation after fracture (%) 0 193.2 398 51.1 20 413.1 445.3 22.7 40 589.1 597.1 10.4 60 621.6 747.4 8.8 80 795.5 832.5 8.6

[0078] Figure 7 The engineering stress-strain curves of the CuSn10P1 alloy ingot prepared in Example 1 underwent cold rolling with different reductions. (See Table 2 and...) Figure 7 It can be seen that with the increase of rolling strain, the strength of the alloy ingot increases while the plasticity decreases. The elongation of 60% reduction and 80% reduction are comparable, but the tensile strength increases by 85 MPa. This is related to dislocation engineering. When the dislocation density reaches a certain range, both strength and plasticity can be improved simultaneously.

[0079] Figure 8 Tensile fracture surface diagrams of CuSn10P1 alloy ingots prepared in Example 1 with different reductions during cold rolling are shown. (a) represents a reduction of 0%, (b) a reduction of 20%, (c) a reduction of 40%, (d) a reduction of 60%, and (e) a reduction of 80%. Figure 8 It can be seen that the fracture surfaces of alloy ingots after stretching with different rolling reductions all exhibit dimple characteristics, with large dimples containing numerous small dimples. As the rolling reduction increases, the number of large dimples first decreases and then increases.

[0080] Example 2 and Comparative Examples 4-5

[0081] A method for preparing large-size high-tin copper alloy ingots with both high plasticity and superior cold-rolling properties:

[0082] Step (1) is the same as in Example 1;

[0083] (2) The high-quality semi-solid metal slurry obtained in step (1) is mixed at 100cm... 3 The material is injected along the mold wall at a speed of 330℃ / s into a mold with a diameter of 80mm and a depth of 350mm for secondary cooling and extrusion. The cooling rate of the secondary cooling is 330℃ / s. Before heating the mold, a high-temperature release agent of Meishu 605 is sprayed on it. After drilling holes in the mold, a metal heating rod with a diameter of Φ of 10mm and a length of 100mm is inserted for heating. When the mold temperature reaches the set extrusion temperature, it is held for 1 hour, and then extrusion begins. The forming specific pressure of the extruder punch is set to 85MPa (Comparative Example 4), 115MPa (Comparative Example 5), and 175MPa (Example 2). The other extrusion process parameters are: extrusion temperature 530℃, punch running speed 21mm / min, and holding time 15s. After holding, the ingot is left to stand in the mold for 2 minutes, and then air-cooled to room temperature to obtain a CuSn10P1 alloy ingot with a diameter of 80mm.

[0084] The tensile strength and cold rolling properties of the CuSn10P1 alloy ingots prepared in Examples 1-2 and Comparative Examples 4-5 are shown in Table 3.

[0085] Table 3. Tensile strength and cold rolling properties of CuSn10P1 alloy ingots prepared in Examples 1-2 and Comparative Examples 4-5

[0086]

[0087] As shown in Table 3, with the increase of forming pressure, the elongation of the alloy ingot increases, while the tensile strength shows a trend of first increasing and then decreasing. Meanwhile, low forming pressure leads to a decrease in the density of the ingot, and shrinkage cavities inside the ingot cause cold rolling cracking. Higher forming pressure can improve the density of the ingot's internal structure, but excessively high forming pressure may cause semi-solid metal slurry to seep out from the mold edge, affecting the alloy composition.

[0088] Example 3 and Comparative Example 6

[0089] A method for preparing large-size high-tin copper alloy ingots with both high plasticity and superior cold-rolling properties:

[0090] Step (1) is the same as in Example 1;

[0091] (2) The high-quality semi-solid metal slurry obtained in step (1) is mixed at 100cm... 3 The material is injected into a mold with a diameter of 80 mm and a depth of 350 mm at a speed of / s for secondary cooling and extrusion. The cooling rate of the secondary cooling is 330℃ / s. Before heating the mold, a high-temperature release agent of Meishu 605 is sprayed on it. After drilling holes in the mold, a metal heating rod with a diameter of Φ of 10 mm and a length of 100 mm is inserted for heating. When the mold temperature reaches the set extrusion temperature, it is held for 1 hour, and then extrusion begins. The extrusion process parameters are: extrusion temperature 530℃, forming specific pressure 145MPa, punch running speed 21mm / min, and holding time 15s. After holding, the ingot is left to stand in the mold for 1 minute (Comparative Example 6) and 3 minutes (Example 3), and then air-cooled to room temperature to obtain a CuSn10P1 alloy ingot with a diameter of 80 mm.

[0092] The tensile strength and cold rolling properties of the CuSn10P1 alloy ingots prepared in Examples 1, 3 and Comparative Example 6 are shown in Table 4.

[0093] Table 4. Tensile strength and cold rolling properties of CuSn10P1 alloy ingots prepared in Examples 1, 3 and Comparative Example 6.

[0094]

[0095] As shown in Table 4, the mechanical properties of the ingot became extremely poor under the process of standing for 1 minute. This is likely because the ingot was removed from the mold before it was fully solidified. During the removal process, the ingot, which was not fully solidified, developed microcracks, and the sample cracked at 80% cold rolling reduction. In contrast, the samples that stood for 2 and 3 minutes showed excellent elongation and tensile strength, and did not crack even when the cold rolling reduction reached 80%.

[0096] Comparative Example 7

[0097] A method for preparing CuSn10P1 alloy ingots:

[0098] The alloy ingot blank containing the δ phase (Comparative Example 3) obtained at a mold temperature of 490℃ was placed in a heat treatment furnace and subjected to homogenization heat treatment at 600℃ for 120h. Then it was naturally cooled to room temperature to obtain a CuSn10P1 alloy ingot without the δ phase.

[0099] Figure 9 The image shows the microstructure of the CuSn10P1 alloy ingot prepared in Comparative Example 7, where (a2) is a magnified view of (a1), and (a3) ​​is the Sn and P distribution diagram of (a2). Figure 9It can be seen that although the brittle δ phase can be eliminated after traditional homogenization heat treatment, the grain size of the alloy ingot increases and the number of pores increases. The tensile strength of the ingot was measured to be 296 MPa, the elongation after fracture was 49%, and the sample cracked after cold rolling to 80% reduction. Furthermore, this method has a long process flow, long production cycle, and high cost; the presence of pores inside the alloy ingot can lead to cracking of the material during cold rolling.

[0100] Comparative Example 8

[0101] The difference from Example 1 is that in step (1), the cooling rate of the rapid quenching treatment is 360°C / s, while the rest is the same as in Example 1.

[0102] Comparative Example 9

[0103] The difference from Example 1 is that in step (1), the cooling rate of the rapid quenching treatment is 480°C / s, while the rest is the same as in Example 1.

[0104] Comparative Example 10

[0105] The difference from Example 1 is that in step (2), the high-quality semi-solid metal slurry obtained in step (1) is mixed at 100cm... 3 The material is injected at a speed of / s into a mold with a diameter of 80mm and a depth of 300mm along the mold wall, and the rest is the same as in Example 1.

[0106] Comparative Example 11

[0107] The difference from Example 1 is that in step (2), the high-quality semi-solid metal slurry obtained in step (1) is mixed at 100cm... 3 The material is injected at a speed of / s into a mold with a diameter of 80mm and a depth of 350mm along the vertical central axis of the mold, and the rest is the same as in Example 1.

[0108] Comparative Example 12

[0109] The difference from Example 1 is that in step (2), the extrusion temperature is 580°C, and the rest is the same as in Example 1.

[0110] The tensile strength and cold rolling properties of the CuSn10P1 alloy ingots prepared in Comparative Examples 8–12 are shown in Table 5.

[0111] Table 5 shows the tensile strength and cold rolling properties of CuSn10P1 alloy ingots prepared in Comparative Examples 8–12.

[0112]

[0113] As can be seen from Table 5, changing the cooling rate of rapid quenching, the depth of the mold, the injection method of high-quality semi-solid metal slurry, and the extrusion temperature will significantly reduce the tensile strength and cold rolling performance of CuSn10P1 alloy ingots.

[0114] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for preparing a large-size high-tin copper alloy ingot with high plasticity and superior cold rolling performance, characterized in that, The preparation method comprises the following steps: (1) melting high-tin copper alloy, and then performing rapid chilling treatment to obtain semi-solid metal slurry; the cooling speed of the rapid chilling treatment is 400-450℃ / s; (2) performing homogenization treatment on the semi-solid metal slurry obtained in step (1) to obtain high-quality semi-solid metal slurry; (3) injecting the high-quality semi-solid metal slurry obtained in step (2) into a mold, and then performing secondary chilling and extrusion to obtain the large-size high-tin copper alloy ingot with high plasticity and superior cold rolling performance; the diameter of the mold is 80-100mm, the depth of the mold is 350-400mm; the temperature of the extrusion is 520-550℃, the forming specific pressure of the extrusion is 145-175MPa, and the holding time of the extrusion is 2-3min.

2. The production method according to claim 1, characterized by, In step (1), the temperature of the melting is 1100-1190℃, and the holding time of the melting is 5-9min.

3. The production method according to claim 1, characterized by, In step (2), the temperature of the homogenization treatment is 990-1000℃, and the holding time of the homogenization treatment is 10-30s.

4. The method of claim 1, wherein, In step (3), the cooling speed of the secondary chilling is 300-350℃ / s.

5. The preparation method according to claim 1, characterized in that, In step (1), the melting further comprises a slagging-off and standing step.

6. The production method according to claim 5, wherein The temperature of the metal liquid after the standing is 1085-1095℃.

7. The large-size high-tin copper alloy ingot with high plasticity and superior cold rolling performance prepared by the preparation method in any one of claims 1-6.

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