High-strength nickel-silicon bronze bar and method for producing the same
By employing processes such as vacuum casting, hot forging, hot extrusion, and bright annealing, the problem of limited improvement in the mechanical properties of existing nickel-silicon bronze alloys has been solved, and high-strength nickel-silicon bronze busbars have been prepared, achieving significant improvements in hardness and elongation as well as grain refinement.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- YANTAI WANLONG VACUUM METALLURGY
- Filing Date
- 2026-03-11
- Publication Date
- 2026-06-05
AI Technical Summary
Existing nickel-silicon bronze alloys offer limited improvements in mechanical properties, particularly hardness and tensile strength, and existing methods are either costly or do not provide significant performance improvements.
High-strength nickel-silicon bronze busbars are prepared by using a process flow of vacuum casting, hot forging, hot extrusion, drawing, and bright annealing, and by controlling the ratio of nickel, silicon, and magnesium and process parameters. The process includes vacuum casting, preheating treatment, multiple hot forgings, machining, extrusion drawing, and bright annealing.
High-strength nickel-silicon bronze busbars with hardness ≥280HB, elongation ≥17.3%, and conductivity ≥35%IACS were prepared, with refined grains and improved uniformity.
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Abstract
Description
Technical Field
[0001] This invention belongs to the field of copper alloy preparation technology, specifically relating to a high-strength nickel-silicon bronze busbar and its preparation method. Background Technology
[0002] Nickel-silicon bronze is a high-strength, corrosion-resistant copper alloy primarily composed of copper, nickel, and silicon. This alloy possesses high hardness and strength, along with good corrosion resistance, friction resistance, and fatigue strength. It is commonly used in marine engineering, chemical equipment, and shipbuilding for bearings, gears, and transmission components. In recent years, with the upgrading and expansion of its applications, higher requirements have been placed on the mechanical properties of nickel-silicon bronze alloys.
[0003] Currently, domestic methods typically involve altering the nickel-silicon content to enhance the performance of C70250 nickel-silicon bronze alloys. However, the strengthening effect of adding nickel and silicon is not significant, and the tensile strength and hardness are usually not greatly improved.
[0004] Chinese invention patent CN101717877A discloses a copper-nickel-silicon bronze alloy material and its preparation method. The specific composition, by weight percentage, is: nickel 1.6-2.2%, silicon 0.4-0.8%, rare earth alloy 0.008%, and copper 96.002-97.002%. The mechanical properties of the aforementioned copper-nickel-silicon bronze alloy material are: hardness 120 HB. Adding rare earth elements, which are subject to strict control in recent years, to strengthen the alloy not only increases manufacturing costs but also does not significantly improve performance.
[0005] Chinese invention patent CN117488133A discloses the preparation and application of a low-nickel silicon bronze alloy material, specifically composed of: nickel 1-1.6 wt.%, silicon 0.2-0.35 wt.%, chromium 0.1-0.25 wt.%, phosphorus 0.01-0.03 wt.%, with the balance being copper. This low-nickel silicon bronze alloy material reduces the content of both nickel and silicon in its alloy preparation, but its hardness can only reach a maximum of 189 HB.
[0006] Chinese invention patent CN106399748A discloses a novel copper-nickel-silicon alloy material for leadframes and its preparation method. The specific composition is: Ni 0.8-1.8%, Si 0.15-0.35%, Mg 0.10-0.15%, P 0.01-0.05%, Fe 0.05-0.1%, Cr 0.2-0.4%, Zn 0.07-0.15%, with trace elements accounting for 0.02-0.5%, and the balance being copper. The highest hardness achieved by this copper-nickel-silicon alloy material is only 181 HB, indicating no significant improvement in performance.
[0007] The three methods for preparing nickel-silicon bronze alloys mentioned above have limitations in terms of content, ratio, and cost. To address the problems and limitations of existing methods, and given the domestic market demand for high-strength nickel-silicon bronze alloys, there is an urgent need to propose a "high-nickel, low-silicon content" nickel-silicon bronze alloy material and its preparation method to significantly improve the alloy's mechanical properties. Summary of the Invention
[0008] To address the shortcomings of the existing technology, this invention provides a high-strength nickel-silicon bronze busbar and its preparation method, which has a hardness ≥280HB, elongation ≥14.3%, electrical conductivity ≥35%IACS, and refined grains with improved uniformity.
[0009] The specific technical solution is as follows: The first objective of this invention is to provide a method for preparing a high-strength nickel-silicon bronze busbar, comprising the following steps: firstly, the raw materials are prepared, comprising the following components by mass percentage: nickel 2.0-2.5 wt%, silicon 0.5-0.9 wt%, magnesium 0.1-0.2 wt%, with the remainder being copper, and the total weight percentage of impurities not exceeding 0.5 wt%; then, a copper alloy ingot is vacuum cast, and after hot forging deformation, hot extrusion deformation, and drawing, the nickel-silicon bronze busbar is obtained by annealing.
[0010] Furthermore, the preparation method of the high-strength nickel-silicon bronze busbar specifically includes the following steps: S1. Ingredients: Ingredients shall be prepared according to the following weight percentages: nickel 2.0-2.5wt%, silicon 0.5-0.9wt%, magnesium 0.1-0.2wt%, with the remainder being copper, and the total weight percentage of impurities not exceeding 0.5wt%. S2. Vacuum casting: Electrolytic copper and electrolytic nickel are placed in a vacuum melting furnace. Since silicon and magnesium will be lost during the melting process, they are placed in a small hopper in the vacuum melting furnace. A vacuum of 100-300 Pa is drawn and maintained until casting. At the same time, the temperature is raised, silicon and metallic magnesium are added, and the temperature is raised again for refining. Nitrogen is introduced to break the vacuum, and the casting is completed. After casting, the casting is cooled and demolded to obtain a copper alloy ingot. During the process, while drawing a vacuum, the temperature is raised to 1100-1200℃ until all the furnace charge is melted and stirred. The partition below the small hopper is opened, and silicon and metallic magnesium are added. The temperature is then raised to 1250-1270℃ and held for 15-20 minutes for refining. The temperature is then lowered to 1120-1150℃, nitrogen is introduced to break the vacuum, and casting begins. S3. Preheating treatment: The copper alloy ingot obtained in S2 is placed in a heat preservation furnace for preheating and heat preservation. The preheating temperature is 870-950℃ and the heat preservation time is 2-4h. S4. Forging: The ingot after heat preservation is hot forged. The deformation amount of the first hot forging is 50-70%. After the hot forging is completed, it is returned to the furnace for heat preservation. The second hot forging is started, with a deformation amount of 50-70%. It is then returned to the furnace for heat preservation again. The third hot forging is to form a round bar. The hot forging is completed. The hot forging temperature is always greater than 700℃. S5. Machining: The copper alloy bar after hot forging (i.e., the round bar formed by the third hot forging) is machined to remove a layer of oxide scale on the surface and machined into an extrusion billet. S6. Extrusion and drawing: Preheat the extrusion billet to 800-900℃ and hold for 1-2 hours, then perform hot extrusion with an extrusion ratio of 20-45, followed by drawing with a drawing deformation of 30-60%; S7. Bright annealing: Anneal at 400-420℃ for 2-5 hours, followed by air cooling to obtain the nickel-silicon bronze busbar.
[0011] The second objective of this invention is to provide a high-strength nickel-silicon bronze busbar, which is prepared by the preparation method described above.
[0012] Compared with the prior art, the beneficial effects of the present invention are as follows: The preparation method provided by this invention first uses a vacuum casting process to ensure the composition of the ingot, reduce the generation of impurities, and effectively guarantee the conductivity. Then, it uses an extrusion and drawing process to improve its hardness, so that the prepared nickel-silicon bronze busbar has a hardness ≥280HB, elongation ≥17.3%, conductivity ≥35%IACS, and the grains are refined and the uniformity is improved. Detailed Implementation
[0013] The principles and features of the present invention are described below with reference to examples. The examples are only used to explain the present invention and are not intended to limit the scope of the present invention.
[0014] Example 1 A method for preparing a high-strength nickel-silicon bronze busbar specifically includes the following steps: S1. Ingredients: Ingredients shall be prepared according to the following weight percentages: nickel 2.5wt%, silicon 0.9wt%, magnesium 0.1wt%, with the remainder being copper, and the total weight percentage of impurities not exceeding 0.5wt%. S2. Vacuum casting: Electrolytic copper and electrolytic nickel are placed in a vacuum melting furnace. Since silicon and magnesium are lost during the melting process, they are placed in a small hopper inside the vacuum melting furnace. A vacuum of 100 Pa is drawn and maintained until casting. At the same time, the temperature is raised to 1150°C until all the furnace charge is melted. Stirring is performed, and the partition at the bottom of the small hopper is opened to add silicon and metallic magnesium. The temperature is raised to 1260°C and held for 15 minutes for refining. The temperature is then lowered to 1135°C, and nitrogen is introduced to break the vacuum. Casting begins. After casting, the mixture is cooled and demolded to obtain a copper alloy ingot. S3. Preheating treatment: The copper alloy ingot obtained in S2 is placed in a heat preservation furnace for preheating and heat preservation. The preheating temperature is 900℃ and the heat preservation time is 3h. S4. Forging: The ingot after heat preservation is hot forged. The deformation amount of the first hot forging is 60%. After the hot forging is completed, it is returned to the furnace for heat preservation. The second hot forging is started, with a deformation amount of 60%. It is then returned to the furnace for heat preservation again. The third hot forging is to form a round bar. The hot forging is completed. The hot forging temperature is always greater than 700℃. S5. Machining: The copper alloy bar after hot forging (i.e., the round bar formed by the third hot forging) is machined to remove a layer of oxide scale on the surface and machined into an extrusion billet. S6. Extrusion and drawing: The extrusion billet is preheated to 850℃ and held for 2 hours, then hot extruded at an extrusion ratio of 30, followed by drawing with a drawing deformation of 40%. S7. Bright annealing: Anneal at 410℃ for 4 hours, followed by air cooling to obtain the nickel-silicon bronze busbar.
[0015] Example 2 A method for preparing a high-strength nickel-silicon bronze busbar specifically includes the following steps: S1. Ingredients: Ingredients shall be prepared according to the following weight percentages: nickel 2.2wt%, silicon 0.6wt%, magnesium 0.15wt%, with the remainder being copper, and the total weight percentage of impurities not exceeding 0.5wt%. S2. Vacuum casting: Electrolytic copper and electrolytic nickel are placed in a vacuum melting furnace. Since silicon and magnesium are lost during the melting process, they are placed in a small hopper inside the vacuum melting furnace. A vacuum of 200 Pa is drawn and maintained until casting. At the same time, the temperature is raised to 1100℃ until all the furnace charge is melted. Stirring is performed, and the partition at the bottom of the small hopper is opened to add silicon and metallic magnesium. The temperature is raised to 1250℃ and held for 15 minutes for refining. The temperature is then lowered to 1120℃, and nitrogen is introduced to break the vacuum. Casting begins. After casting, the mixture is cooled and demolded to obtain a copper alloy ingot. S3. Preheating treatment: The copper alloy ingot obtained in S2 is placed into a heat preservation furnace for preheating and heat preservation. The preheating temperature is 870℃ and the heat preservation time is 2h. S4. Forging: The ingot after heat preservation is hot forged. The deformation amount of the first hot forging is 50%. After the hot forging is completed, it is returned to the furnace for heat preservation. The second hot forging is started, with a deformation amount of 50%. It is then returned to the furnace for heat preservation again. The third hot forging is to form a round bar. The hot forging is completed. The hot forging temperature is always greater than 700℃. S5. Machining: The copper alloy bar after hot forging (i.e., the round bar formed by the third hot forging) is machined to remove a layer of oxide scale on the surface and machined into an extrusion billet. S6. Extrusion and drawing: The extrusion billet is preheated to 800℃ and held for 1.5 hours, then hot extruded at an extrusion ratio of 20, followed by drawing with a drawing deformation of 30%. S7. Bright annealing: Anneal at 400℃ for 2 hours, followed by air cooling to obtain the nickel-silicon bronze busbar.
[0016] Example 3 A method for preparing a high-strength nickel-silicon bronze busbar specifically includes the following steps: S1. Ingredients: Ingredients shall be prepared according to the following weight percentages: nickel 2wt%, silicon 0.5wt%, magnesium 0.2wt%, with the remainder being copper, and the total weight percentage of impurities not exceeding 0.5wt%. S2. Vacuum casting: Electrolytic copper and electrolytic nickel are placed in a vacuum melting furnace. Since silicon and magnesium are lost during the melting process, they are placed in a small hopper inside the vacuum melting furnace. A vacuum of 300 Pa is drawn and maintained until casting. At the same time, the temperature is raised to 1200℃ until all the furnace charge is melted. Stirring is performed, and the partition at the bottom of the small hopper is opened to add silicon and metallic magnesium. The temperature is raised to 1270℃ and held for 20 minutes for refining. The temperature is then lowered to 1150℃, and nitrogen is introduced to break the vacuum. Casting begins. After casting, the mixture is cooled and demolded to obtain a copper alloy ingot. S3. Preheating treatment: The copper alloy ingot obtained in S2 is placed in a heat preservation furnace for preheating and heat preservation. The preheating temperature is 950℃ and the heat preservation time is 4h. S4. Forging: The ingot after heat preservation is hot forged. The deformation amount of the first hot forging is 70%. After the hot forging is completed, it is returned to the furnace for heat preservation. The second hot forging is started, with a deformation amount of 70%. It is returned to the furnace for heat preservation again. The third hot forging is into a round bar. The hot forging is completed. The hot forging temperature is always greater than 700℃. S5. Machining: The copper alloy bar after hot forging (i.e., the round bar formed by the third hot forging) is machined to remove a layer of oxide scale on the surface and machined into an extrusion billet. S6. Extrusion and drawing: The extrusion billet is preheated to 900℃ and held for 1 hour, then hot extruded at an extrusion ratio of 45, followed by drawing with a drawing deformation of 60%. S7. Bright annealing: Anneal at 420℃ for 5 hours, followed by air cooling to obtain the nickel-silicon bronze busbar.
[0017] Comparative Example 1 A method for preparing a nickel-silicon bronze busbar specifically includes the following steps: S1. Ingredients: Ingredients shall be prepared according to the following weight percentages: nickel 2wt%, silicon 0.5wt%, magnesium 0.2wt%, with the remainder being copper, and the total weight percentage of impurities not exceeding 0.5wt%. S2. Vacuum casting: Electrolytic copper and electrolytic nickel are placed in a vacuum melting furnace. Since silicon and magnesium are lost during the melting process, they are placed in a small hopper inside the vacuum melting furnace. A vacuum of 300 Pa is drawn and maintained until casting. At the same time, the temperature is raised to 1050℃ until all the furnace charge is melted. Stirring is performed, and the partition at the bottom of the small hopper is opened to add silicon and metallic magnesium. The temperature is raised to 1150℃ and held for 20 minutes for refining. The temperature is then lowered to 1050℃, and nitrogen is introduced to break the vacuum. Casting begins. After casting, the mixture is cooled and demolded to obtain a copper alloy ingot. S3. Preheating treatment: The copper alloy ingot obtained in S2 is placed in a heat preservation furnace for preheating and heat preservation. The preheating temperature is 950℃ and the heat preservation time is 4h. S4. Forging: The ingot after heat preservation is hot forged. The deformation amount of the first hot forging is 70%. After the hot forging is completed, it is returned to the furnace for heat preservation. The second hot forging is started, and the deformation amount of the hot forging is 70%. During the second hot forging, cracking occurred. The analysis shows that the melting temperature was too low, resulting in more impurities, or that silicon elements agglomerated and formed segregation.
[0018] Comparative Example 2 A method for preparing a nickel-silicon bronze busbar specifically includes the following steps: S1. Ingredients: Ingredients shall be prepared according to the following weight percentages: nickel 2.5wt%, silicon 0.9wt%, magnesium 0.1wt%, with the remainder being copper, and the total weight percentage of impurities not exceeding 0.5wt%. S2. Vacuum casting: Electrolytic copper and electrolytic nickel are placed in a vacuum melting furnace. Since silicon and magnesium are lost during the melting process, they are placed in a small hopper inside the vacuum melting furnace. A vacuum of 100 Pa is drawn and maintained until casting. At the same time, the temperature is raised to 1150°C until all the furnace charge is melted. Stirring is performed, and the partition at the bottom of the small hopper is opened to add silicon and metallic magnesium. The temperature is raised to 1260°C and held for 15 minutes for refining. The temperature is then lowered to 1135°C, and nitrogen is introduced to break the vacuum. Casting begins. After casting, the mixture is cooled and demolded to obtain a copper alloy ingot. S3. Preheating treatment: The copper alloy ingot obtained in S2 is placed in a heat preservation furnace for preheating and heat preservation. The preheating temperature is 900℃ and the heat preservation time is 3h. S4. Forging: The ingot after heat preservation is hot forged. The deformation amount of the first hot forging is 40%. After the hot forging is completed, it is returned to the furnace for heat preservation. The second hot forging is started, with a deformation amount of 40%. It is then returned to the furnace for heat preservation again. The third hot forging is to form a round bar. The hot forging is completed. The hot forging temperature is always greater than 700℃. S5. Machining: The copper alloy bar after hot forging (i.e., the round bar formed by the third hot forging) is machined to remove a layer of oxide scale on the surface and machined into an extrusion billet. S6. Extrusion and drawing: The extrusion billet is preheated to 850℃ and held for 2 hours, then hot extruded with an extrusion ratio of 15, followed by drawing with a drawing deformation of 25%. S7. Bright annealing: Anneal at 410℃ for 4 hours, followed by air cooling to obtain the nickel-silicon bronze busbar.
[0019] Because the forging (hot forging) deformation, extrusion ratio and drawing deformation are reduced in this process (Comparative Example 2), the grains are not completely broken and there are large grains. After annealing, they are not completely recrystallized, resulting in a decrease in overall performance.
[0020] test: The nickel-silicon bronze busbars prepared in Examples 1-3 and Comparative Example 2 were subjected to equidistant hardness and electrical conductivity tests, with at least 9 test values, and the average value was taken. The elongation was tested by tensile test, with 3 products tested and the average value taken.
[0021] The testing standards are as follows: elongation is tested according to GB / T 228.1-2010 "Metallic materials - Tensile testing - Part 1: Test method at room temperature"; hardness is tested according to GB / T 231.1-2018 "Metallic materials - Brinell hardness test - Part 1: Test method"; conductivity is tested according to GB / T 32791-2016 "Eddy current test method for conductivity of copper and copper alloys".
[0022] The product test data of Examples 1-3 and Comparative Example 2 are shown in Table 1.
[0023] Table 1 Test data of Examples 1-3 and Comparative Example 2
[0024] By comparing the test data in Table 1, it can be seen that the hardness of the nickel-silicon bronze busbar product prepared in the embodiment of the present invention is ≥280HB, which is much higher than that of the comparative product; the elongation of the product prepared in the embodiment of the present invention is ≥17.3%, the electrical conductivity is ≥35%IACS, and the grains are refined and the uniformity is improved.
[0025] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.
Claims
1. A method for preparing a high-strength nickel-silicon bronze busbar, characterized in that, Includes the following steps: First, the raw materials are prepared, including the following components by weight percentage: nickel 2.0-2.5wt%, silicon 0.5-0.9wt%, magnesium 0.1-0.2wt%, with the remainder being copper, and the total weight percentage of impurities not exceeding 0.5wt%. Then, the copper alloy ingot is vacuum-cast, and after hot forging, hot extrusion, and drawing, it is annealed to obtain the nickel-silicon bronze busbar.
2. The method for preparing high-strength nickel-silicon bronze busbars according to claim 1, characterized in that, Specifically, the following steps are included: S1. Ingredients: Ingredients shall be prepared according to the following weight percentages: nickel 2.0-2.5wt%, silicon 0.5-0.9wt%, magnesium 0.1-0.2wt%, with the remainder being copper, and the total weight percentage of impurities not exceeding 0.5wt%. S2. Vacuum casting: Electrolytic copper and electrolytic nickel are placed in a vacuum melting furnace, silicon and metallic magnesium are placed in a small hopper, a vacuum is drawn, and the temperature is raised at the same time. Silicon and metallic magnesium are added, and the temperature is raised again for refining. Nitrogen is introduced to break the vacuum, and the mixture is cast into shape. After casting, it is cooled and demolded to obtain a copper alloy ingot. S3. Preheating treatment: The copper alloy ingot obtained in S2 is placed into a heat preservation furnace for preheating and heat preservation. S4. Forging: Hot forging the ingot after heat preservation; S5. Machining: Machining the material after hot forging to remove surface oxide scale and machine it into extruded billets; S6. Extrusion and drawing: The extrusion billet is preheated, then hot-extruded, and then drawn. S7. Bright annealing: Annealing is performed, followed by air cooling, to obtain the nickel-silicon bronze busbar.
3. The method for preparing high-strength nickel-silicon bronze busbars according to claim 2, characterized in that, In step S2, while evacuating the vacuum, the temperature is raised to 1100-1200℃ until all the furnace charge is melted and cleared. Stirring is performed, the partition below the small hopper is opened, and silicon and metallic magnesium are added. The temperature is raised to 1250-1270℃ and held for 15-20 minutes for refining. The temperature is then lowered to 1120-1150℃, nitrogen is introduced to break the vacuum, and casting begins.
4. The method for preparing high-strength nickel-silicon bronze busbars according to claim 2, characterized in that, In step S2, the vacuum level is 100-300 Pa.
5. The method for preparing high-strength nickel-silicon bronze busbars according to claim 2, characterized in that, In step S3, the preheating temperature is 870-950℃, and the heat preservation time is 2-4 hours.
6. The method for preparing high-strength nickel-silicon bronze busbars according to claim 2, characterized in that, In step S4, the hot forging is performed in three stages, as follows: the deformation amount of the first hot forging is 50-70%, and after the hot forging is completed, it is returned to the furnace for heat preservation; the second hot forging begins, with a deformation amount of 50-70%, and it is returned to the furnace for heat preservation again; the third hot forging is performed to form a round bar, and the hot forging is completed.
7. The method for preparing high-strength nickel-silicon bronze busbars according to claim 2, characterized in that, In step S4, the temperature of the hot forging is always greater than 700°C.
8. The method for preparing high-strength nickel-silicon bronze busbars according to claim 2, characterized in that, In step S6, the preheating temperature is 800-900℃ and the holding time is 1-2h; the extrusion ratio of the hot extrusion is 20-45 and the deformation of the drawing is 30-60%.
9. The method for preparing high-strength nickel-silicon bronze busbars according to claim 2, characterized in that, In step S7, the annealing temperature is 400-420℃ and the time is 2-5 hours.
10. A high-strength nickel-silicon bronze busbar, characterized in that, It is prepared by the preparation method described in any one of claims 1 to 9.