A novel temperature-resistant and wear-resistant copper alloy and its application

Abstract

The present invention relates to a new type of temperature-bearing and wear-resistant copper alloy and its application, belonging to the technical field of non-ferrous metal materials and their preparation. It solves the technical problems of insufficient wear resistance and working stability of the copper wire nut in a high-temperature environment. The solution is as follows: The composition and mass percentage of the new type of temperature-bearing and wear-resistant copper alloy are: zinc: 35% - 42%, aluminum: 2% - 4%, manganese: 4% - 7%, nickel: 0.4% - 0.7%, silicon-chromium-iron alloy, 4% - 7%, and the balance is copper; this new type of temperature-bearing and wear-resistant copper alloy is used to prepare a copper alloy part that works by friction in a high-temperature environment - the copper wire nut, and the preparation process steps of the copper wire nut are disclosed. By optimizing the composition, ratio, and preparation process flow of the copper alloy, the present invention improves the wear resistance and strength of the copper alloy, is suitable for preparing high-strength and wear-resistant components such as copper wire nuts, and has broad application prospects and significant economic value.

Description

Technical Field

[0001] The present invention belongs to the technical field of non-ferrous metal materials and their preparation, and particularly relates to a new type of temperature-resistant and wear-resistant copper alloy and its application. Background Art

[0002] The copper wire nut is an important transmission part in forging equipment of the friction or electric series. The copper wire nut and the screw rod together form a friction pair for power transmission. At present, the material of the copper wire nut is usually ZHAl66-6-3-2 copper alloy. The copper wire nut has a high usage frequency and a long continuous working time. Under the combined action of the mutual friction between the copper wire nut and the screw rod and the environmental temperature, the working temperature of the copper wire nut rises (the actual working temperature reaches 100°C - 200°C). At this temperature, the wear resistance of the copper wire nut weakens, and generally the copper wire nut fails and cannot be used normally after 12 - 15 months of use, increasing the use cost of the forging equipment and affecting the operation efficiency of the equipment.

[0003] Therefore, there is an urgent need to develop a copper alloy material that can resist high temperature, has good wear resistance and stable use performance in a high-temperature environment for preparing copper wire nuts. Summary of the Invention

[0004] The main purpose of the present invention is to overcome the deficiencies in the prior art, solve the technical problems of insufficient wear resistance and working stability of the copper wire nut in a high-temperature environment. The present invention provides a new type of temperature-resistant and wear-resistant copper alloy and its application. By designing the composition and ratio of the copper alloy material and optimizing the preparation process, the wear resistance and use stability of the copper alloy at high temperature are improved, thereby increasing the service life of the copper wire nut and meeting the use requirements of forging equipment of the friction or electric series.

[0005] The present invention is achieved through the following technical solutions: A new type of temperature-resistant and wear-resistant copper alloy, its composition and mass percentage are: zinc: 35% - 42%, aluminum: 2% - 4%, manganese: 4% - 7%, nickel: 0.53% - 0.64%, silicon-chromium-iron alloy, 4% - 7%, and the rest is copper.

[0006] Further, the composition and mass percentage of the silicon-chromium-iron alloy are: Si: 20% - 40%, Cr: 20% - 40%, Fe: 30% - 50%, and the sum of the mass percentages of each element is 100%.

[0007] The present invention uses a copper-zinc alloy as the matrix, and adds aluminum, manganese, nickel alloy elements and a silicon-chromium-iron alloy to form a new type of temperature-resistant and wear-resistant copper alloy. The functions of each chemical element in the alloy are as follows.

[0008] Aluminum (Al): The aluminum element can form a solid solution in the alloy. By replacing copper or zinc atoms, it enhances the strength and hardness of the alloy, inhibits the formation of the copper-zinc phase, and improves the thermal stability and wear resistance of the alloy.

[0009] Manganese (Mn): The manganese element can effectively control the precipitation of zinc in the alloy. Especially in high-temperature environments, it can improve the stability of the alloy and reduce the impact of precipitates on the alloy's performance.

[0010] Nickel (Ni): Refines the alloy grains, improves its corrosion resistance, and slows down the corrosion rate.

[0011] Silicon-chromium-iron alloy:

[0012] Silicon (Si): The zinc equivalent coefficient of the silicon element is as high as 10, which will sharply narrow the α-phase region of the copper alloy. When the content of the silicon element increases, a new phase κ with a close-packed hexagonal lattice will appear. This phase has sufficient plasticity at high temperatures and decomposes into an (α + γ) eutectoid at a certain temperature, thereby improving the strength and hardness of the alloy and enhancing the wear resistance and fatigue resistance of the material.

[0013] Chromium (Cr): The chromium element can form stable solid solutions or precipitation phases in the alloy, improving the hardness, strength, and high-temperature resistance of the alloy. And it forms a passive film with oxygen at high temperatures, which helps to improve the corrosion resistance and heat resistance of the alloy. The reasons are as follows: On the one hand, chromium can form Zn-Cr compounds with zinc, which helps to improve the strength and corrosion resistance of the alloy; on the other hand, when the addition amount of the chromium element exceeds its solid solubility limit in this copper alloy, chromium atoms will precipitate in the form of second-phase particles and disperse in the matrix. These precipitated chromium particles can play a role in dispersion strengthening, further improving the strength and hardness of the brass alloy.

[0014] Iron (Fe): The iron element helps to refine the grains, inhibit grain growth, and improve the mechanical properties of the alloy.

[0015] Furthermore, the composition and mass percentage of the new temperature-resistant and wear-resistant copper alloy are as follows: zinc: 38.51% - 38.71%, aluminum: 2.64% - 2.91%, manganese: 5.42% - 5.64%, silicon-chromium-iron alloy: 6.03% - 6.28%, nickel: 0.53% - 0.64%, copper: 46.89% - 47.02%, and the sum of the mass percentages of each element is 100%.

[0016] An application of the new temperature-resistant and wear-resistant copper alloy as described above, wherein: the new temperature-resistant and wear-resistant copper alloy is used to prepare copper alloy parts that work by friction in high-temperature environments.

[0017] Furthermore, the copper alloy part is a copper wire nut.

[0018] Furthermore, the preparation process of the copper wire nut includes the following steps:

[0019] S1. Weigh electrolytic copper plates, electrolytic nickel plates, zinc ingots, aluminum ingots, electrolytic manganese plates, and silicon-chromium-iron alloys as raw materials according to the composition and mass percentage of the new temperature-resistant and wear-resistant copper alloy for later use;

[0020] S2. Select corresponding centrifugal casting molds and tooling according to the design size specifications of the copper wire mother. Uniformly coat the inner wall of the centrifugal casting mold cavity with graphite coating, and the coating thickness is 0.5 mm to 1 mm. After the graphite coating is applied, bake the centrifugal casting mold at a baking temperature of 300 °C to 350 °C for 2 hours, and finally keep it warm at a temperature of 180 °C to 230 °C for 3 hours for later use;

[0021] S3. Smelting:

[0022] S3-1. Alloy melting:

[0023] First, add the electrolytic copper plates, electrolytic nickel plates, and silicon-chromium-iron alloys weighed in step S1 into the intermediate frequency furnace, send electricity for melting until the materials in the furnace show a red-hot state, keep warm for 50 to 100 minutes, continue to heat up to 1540 °C to 1560 °C. After the materials in the furnace are completely melted, add the refining agent for the first time, stir and refine for 3 to 5 minutes, and cut off the power for the first time to skim the slag;

[0024] Second, after cutting off the power for the first time and skimming the slag, add the electrolytic manganese plates and aluminum ingots into the furnace, send electricity to keep the temperature and continue melting;

[0025] Third, after the raw materials in the intermediate frequency furnace are completely melted, heat up to 1420 °C to 1460 °C, add the refining agent for the second time, refine for 1 to 2 minutes, and cut off the power for the second time to skim the slag;

[0026] Finally, after the alloy liquid in the intermediate frequency furnace is completely transformed into a liquid phase (i.e., all melted), add the zinc ingots into the alloy liquid. After the zinc ingots are completely melted, add the refining agent for the third time and stir evenly, and control the tapping temperature to be 1080 °C to 1200 °C;

[0027] S3-2. Refining and degassing: First, the copper alloy liquid is transferred from the intermediate frequency furnace to the ladle. CuRe15 and CuTi20 are added on the surface of the copper alloy liquid as grain refiners, and the weight of the grain refiners accounts for 0.6% of the weight of the copper alloy solution. Based on the design of the alloy chemical composition, the present invention uses microalloying method to refine the grains of the temperature-bearing wear-resistant copper alloy. After the copper alloy is melted, 0.6% of the grain refiners CuRe15 and CuTi20 (equal mass ratio) are added to the surface of the copper alloy solution. By fully stirring, they react with the elements in the alloy to form high-melting-point compounds. These compounds act as crystallization nuclei during casting and solidification, thus effectively refining the grains and improving the mechanical properties of the alloy. Then, a gas cylinder is connected to the bottom of the ladle, and an inert gas (dry N2) is blown into the copper alloy solution. The gas flow rate is adjusted to 10 L / min - 15 L / min. The inert gas is blown into the ladle for slag removal, exhaust and stirring. When the temperature of the copper alloy solution drops to 1000 °C - 1060 °C, stop blowing, skim the slag, and prepare for casting;

[0028] S3-3. First, start the centrifugal casting equipment, and determine the rotational speed n of the centrifuge according to the design dimensions of the copper wire master casting:

[0029] ;

[0030] In the formula, n is the rotational speed of the centrifugal casting mold, with the unit of r / min; G is the gravity coefficient (generally taken as 60 - 80); r0 is the radius of the inner circle of the copper wire master casting, with the unit of cm;

[0031] Then, after the rotational speed of the centrifugal casting equipment is stable, transfer the ladle in the refining furnace in step S3-2 to the centrifugal casting trolley, and carry out casting according to the principle of "slow first, then fast, and then slow". The casting process should be stable and continuous. Start the cooling spray system 5 - 10 s after the copper alloy liquid is completely injected into the cavity of the centrifugal casting mold. The copper alloy liquid is quickly cooled and solidified. After the centrifugal casting equipment runs continuously for 30 - 40 minutes, stop the machine to obtain the blank of the copper wire master casting;

[0032] S4. Cooling and finishing: Cool the blank of the copper wire master casting prepared in step S3-3 for at least 3 hours, then open the box and clean the flash. Finally, take out the blank of the copper wire master casting from the centrifugal casting mold and naturally cool it to room temperature in the air to obtain the copper wire master casting;

[0033] S5. Machining: Carry out finished machining on the copper wire master casting according to the design dimension requirements and make marks for easy traceability to obtain the new temperature-bearing wear-resistant copper wire master.

[0034] Furthermore, in the step S3-2, the mass ratio of CuRe15 and CuTi20 is 1:1.

[0035] Further, the refining agent added for the first and second times is cryolite, and the refining agent added for the third time is DHCT-L.

[0036] The beneficial effects of the present invention are as follows:

[0037] 1. Significant improvement in wear resistance and strength: By designing the chemical composition ratio of the copper alloy and optimizing the preparation process, the wear resistance and strength of the new copper alloy have been significantly improved, and it can meet the use environment with higher requirements. Compared with the traditional material ZHAl66-6-3-2, the service life has been increased by 80%. The copper wire mother centrifugally cast with this alloy material can be normally installed and used for more than 20 months;

[0038] 2. Optimization of the production process: The present invention comprehensively optimizes the preparation process flow of the copper wire mother, which not only improves the production efficiency but also further enhances the quality stability of the product;

[0039] 3. Enhancement of cost-effectiveness: Through innovative raw material ratio and process optimization, the present invention reduces the input cost of raw materials. Compared with the traditional material ZHAl66-6-3-2, the production cost is reduced by about 25%. Description of the Drawings

[0040] Figure 1 It is the microstructure morphology diagram of ZHAl66-6-3-2 copper alloy;

[0041] Figure 2 It is the microstructure morphology diagram of the new temperature-bearing wear-resistant copper alloy prepared in the embodiment;

[0042] Figure 3 It is the mechanical property curve diagram of the new temperature-bearing wear-resistant copper alloy prepared in the embodiment. Detailed Embodiments

[0043] The present invention will be further described in detail below with reference to the drawings and embodiments.

[0044] In this specific embodiment, taking the preparation of 630T copper wire mother as an example, it includes the following steps:

[0045] S1. Weigh electrolytic copper plates, electrolytic nickel plates, zinc ingots, aluminum ingots, electrolytic manganese plates, and silicon-chromium-iron alloys as raw materials according to the composition and mass percentage of the new temperature-bearing wear-resistant copper alloy for later use;

[0046] In this specific embodiment, the raw materials for preparing 630T copper wire mother and their mass percentages are shown in Table 1 below;

[0047] Table 1 Raw materials for preparing 630T copper wire mother in this embodiment and their mass percentages

[0048]

[0049] Among them, the composition and mass percentage of the silicon-chromium-iron alloy are: Si: 30%, Cr: 30%, Fe (pure iron): 40%.

[0050] S2. Select the corresponding centrifugal casting mold and tooling according to the design size specifications of the 630T copper wire mother, and conduct a detailed inspection to ensure that there are no defects such as cracks and rust on the surface of the centrifugal mold. Uniformly coat the inner wall of the cavity of the centrifugal casting mold with graphite coating, and the coating thickness is 0.5 mm to 1 mm; after the graphite coating is applied, place the centrifugal casting mold in a baking kiln for baking, the baking temperature is 300°C to 350°C, the baking time is 2 hours, and finally keep it warm at a temperature of 180°C to 230°C for 3 hours for later use;

[0051] S3. Smelting:

[0052] S3-1. Alloy melting:

[0053] First, add the electrolytic copper plate, electrolytic nickel plate and silicon-chromium-iron alloy weighed in step S1 into the intermediate frequency furnace, send electricity for melting until the materials in the furnace show a red-hot state, keep warm for 50 to 100 minutes, continue to heat up to 1540°C to 1560°C, and after the materials in the furnace are completely melted, first add a refining agent (cryolite), stir and refine for 3 to 5 minutes, and cut off the power for the first time to skim the slag;

[0054] Secondly, after the first power cut and slag skimming are completed, add the electrolytic manganese plate and aluminum ingot into the furnace, and send electricity to keep the temperature and continue melting;

[0055] Thirdly, after the raw materials in the intermediate frequency furnace are completely melted, heat up to 1420°C to 1460°C, add the refining agent (cryolite) for the second time, refine for 1 to 2 minutes, and cut off the power for the second time to skim the slag;

[0056] Finally, after the alloy liquid in the intermediate frequency furnace is completely transformed into a liquid phase (that is, all melted), add zinc ingots into the alloy liquid. After the zinc ingots are completely melted, add the refining agent (DHCT-L) for the third time and stir evenly, and control the tapping temperature to be 1080°C to 1200°C;

[0057] S3-2. Refining and degassing: First, transfer the copper alloy liquid from the intermediate frequency furnace to the copper ladle. Add CuRe15 and CuTi20 as grain refiners on the surface of the copper alloy liquid. The weight of the grain refiners accounts for 0.6% of the weight of the copper alloy solution, and the mass ratio of CuRe15 and CuTi20 is 1:1; then, connect a gas cylinder at the bottom of the copper ladle, blow inert gas (dry N2) into the copper alloy solution, adjust the gas flow rate to 10 L / min to 15 L / min, blow inert gas into the ladle for slag removal, exhaust and stirring. When the temperature of the copper alloy solution drops to 1000°C to 1060°C, stop blowing gas and skim the slag to prepare for casting;

[0058] S3-3. First, start the centrifugal casting equipment and determine the rotational speed n of the centrifuge according to the design dimensions of the copper wire master casting as follows:

[0059] ;

[0060] In the formula, n is the rotational speed of the centrifugal casting mold, with the unit of r / min; G is the gravity coefficient (generally taken as 60 - 80); r0 is the radius of the inner circle of the copper wire master casting, with the unit of cm;

[0061] Then, after the rotational speed of the centrifugal casting equipment is stable, transfer the ladle in the refining furnace in step S3-2 to the centrifugal casting trolley. The pouring process should be stable and continuous. After the copper alloy liquid is completely injected into the cavity of the centrifugal casting mold for 5 - 10 s, turn on the cooling spray system. The copper alloy liquid is rapidly cooled and solidified. After the centrifugal casting equipment runs continuously for 30 - 40 minutes, stop the machine to obtain the blank of the copper wire master casting;

[0062] S4. Cooling and finishing: Cool the blank of the copper wire master casting prepared in step S3-3 for at least 3 hours, then open the box and clean the flash. Finally, take out the blank of the copper wire master casting from the centrifugal casting mold and naturally cool it to room temperature in the air to obtain the copper wire master casting;

[0063] S5. Machining: Perform finished machining on the copper wire master casting according to the design dimension requirements and make marks for easy traceability to obtain the new type of temperature-bearing and wear-resistant copper wire master.

[0064] Check the performance of the copper wire master prepared in this embodiment, and the test results are as follows.

[0065] I. The chemical composition test results are shown in Table 2 below.

[0066] Table 2 Chemical composition test results of the copper wire master prepared in this embodiment

[0067]

[0068] II. The mechanical property test results at different temperatures are shown in Table 3 below.

[0069] Table 3 Mechanical property test results at different temperatures

[0070]

[0071] The requirements of the press for the mechanical properties of the material are shown in Table 4 below.

[0072] Table 4 Requirements of the press for the mechanical properties of the material

[0073]

[0074] Remark: Technical Conditions for Screw Press JB / T 11869-2014.

[0075] According to the test results in Table 3, under the conditions of room temperature and below 220 °C (as Figure 3 shown), this alloy material exhibits excellent mechanical properties, and all performance indicators remain stable, fully meeting the requirements for the mechanical properties of copper wire nuts in electric and friction series forging equipment.

[0076] III. Wear Resistance Test.

[0077] Grinding Head Material: 40Cr steel (quenched and tempered state, 240 - 270 HB); Use Medium: Butter : Machine Oil = 5 : 1;

[0078] Number of Wear Resistance Cycles: 2000 times; Stroke Distance: 60 mm; Load: 24 N; Cycle Speed: 60 r / min;

[0079] Temperature: From room temperature to 320 °C.

[0080] The test results of wear resistance are shown in Table 5 below.

[0081] Table 5 Test Results of Wear Resistance

[0082]

[0083] As can be seen from Table 5, through the comparison of the test results of the wear resistance test, from room temperature to 140 °C, the mass loss of the above two materials is quite the same. When the copper alloy of ZHAl66 - 6 - 3 - 2 material exceeds 140 °C, its wear resistance drops sharply. While for the copper wire nut prepared by the present invention, when the wear resistance exceeds 240 °C, the wear resistance decreases. Through this comparative test, it can be obtained that the copper alloy material of the present invention has good wear resistance at room temperature and 240 °C and below.

[0084] The above is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the technical field within the technical scope disclosed by the present invention should be covered by the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claimed rights.

Claims

1. A new type of heat-resistant and wear-resistant copper alloy, characterized by: The composition and mass percentage of the new temperature-resistant and wear-resistant copper alloy are: zinc: 35%-42%, aluminum: 2%-4%, manganese: 4%-7%, nickel: 0.4%-0.7%, silicon-chromium-iron alloy: 4%-7%, and the rest is copper; the composition and mass percentage of the silicon-chromium-iron alloy are: Si: 20%-40%, Cr: 20%-40%, Fe: 30%-50%, and the sum of the mass percentages of each element is 100%; The novel temperature-resistant and wear-resistant copper alloy is used to prepare copper wire nuts that work by friction in a high-temperature environment, and the working temperature is 140°C-240°C.

2. A new type of heat-resistant and wear-resistant copper alloy according to claim 1, characterized in that: The composition and mass percentage of the new temperature-resistant and wear-resistant copper alloy are: zinc: 38.51%-38.71%, aluminum: 2.64%-2.91%, manganese: 5.42%-5.64%, silicon-chromium-iron alloy: 6.03%-6.28%, nickel: 0.53%-0.64%, copper: 46.89%-47.02%, and the sum of the mass percentages of each element is 100%.

3. A new type of heat-resistant and wear-resistant copper alloy according to claim 1, characterized in that: The preparation process of the copper wire mother comprises the following steps: S1. According to the composition and mass percentage of the new temperature-resistant and wear-resistant copper alloy, electrolytic copper plates, electrolytic nickel plates, zinc ingots, aluminum ingots, electrolytic manganese plates and silicon-chromium-iron alloy are weighed as raw materials for later use; S2. According to the design size specifications of the copper wire mother, the corresponding centrifugal casting mold and tooling are selected, and the graphite coating is evenly coated on the inner wall of the centrifugal casting mold cavity, and the coating thickness is 0.5mm-1mm; after the graphite coating is completed, the centrifugal casting mold is baked at a baking temperature of 300°C-350°C for 2 hours, and finally kept warm at a temperature of 180°C-230°C for 3 hours, and reserved for use in the next step; S3. Smelting: S3-1. Alloy smelting: First, add the electrolytic copper plate, electrolytic nickel plate and silicon-chromium-iron alloy weighed in step S1 into the medium frequency furnace, power on and smelt until the materials in the furnace are red hot, keep warm for 50 to 100 minutes, continue to heat up to 1540° C. to 1560° C., add the refining agent for the first time after the materials in the furnace are completely melted, stir and refine for 3 to 5 minutes, and cut off the power once to remove the slag; Secondly, after the slagging is completed during a power outage, electrolytic manganese plates and aluminum ingots are added into the furnace, and power is supplied to maintain the temperature and continue smelting; Once again, after the raw materials in the medium frequency furnace are completely melted, the temperature is raised to 1420℃~1460℃, and refining agent is added for the second time. Refining is carried out for 1~2 minutes, and the power is turned off for the second time to remove the slag. Finally, after the alloy liquid in the medium frequency furnace is completely transformed into liquid phase, the zinc ingot is added into the alloy liquid. After the zinc ingot is completely melted, the refining agent is added three times and stirred evenly, and the furnace temperature is controlled to be 1080℃~1200℃; the refining agent added for the first and second time is cryolite, and the refining agent added for the third time is DHCT-L; S3-2, refining and degassing: first, the copper alloy liquid is transferred from the medium frequency furnace to the copper ladle, and CuRe15 and CuTi20 are added as grain refiners on the surface of the copper alloy liquid, and the weight of the grain refiners accounts for 0.6% of the weight of the copper alloy solution; then, a gas cylinder is connected to the bottom of the copper ladle, and an inert gas is blown into the copper alloy solution, and the gas flow rate is adjusted to 10L / min~15L / min. When the temperature of the copper alloy solution drops to 1000℃~1060℃, the blowing is stopped, and the slag is removed to prepare for casting; S3-3. First, start the centrifugal casting equipment and determine the centrifuge speed n according to the design size of the copper wire mother casting: Where n is the centrifugal casting mold speed, unit is r / min; G is the gravity coefficient; r0 is the radius of the inner circle of the copper wire mother casting, unit is cm; Then, after the rotation speed of the centrifugal casting equipment is stabilized, the ladle in the refining furnace of step S3-2 is transferred to the centrifugal casting trolley. The casting process should be smooth and continuous. The copper alloy liquid is completely injected into the centrifugal casting mold cavity. After 5-10 seconds, the cooling spray system is turned on. The copper alloy liquid is quickly cooled and solidified. The centrifugal casting equipment is shut down after continuous operation for 30-40 minutes to obtain the copper wire mother casting blank. S4, cooling and cleaning: cooling the copper wire mother casting blank prepared in step S3-3 for at least 3 hours, then unpacking and cleaning the batch seams, and finally removing the copper wire mother casting blank from the centrifugal casting mold, and naturally cooling it to room temperature in the air to obtain the copper wire mother casting; S5. Machining: The copper wire mother casting is machined into finished products according to the design size requirements and marked for easy traceability to produce a new type of heat-resistant and wear-resistant copper wire mother.

4. A new type of heat-resistant and wear-resistant copper alloy according to claim 3, characterized in that: In the step S3-2, the mass ratio of CuRe15 to CuTi20 is 1:1.

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