Copper alloy and its preparation method and application

Abstract

The present invention discloses a copper alloy and its preparation method and application, belonging to the field of alloy technology. The copper alloy in the present invention includes components such as Cu, Al, Cr, Zr, Ni, Mg, Ti, Si, rare earth elements, and Zn. The copper alloy in the present invention achieves breakthrough improvements in high-temperature strength, resistance to complex corrosion, processing performance, and environmental protection through innovative designs such as Al-Cr-Si oxide film synergistic protection, Zr-Ti-Mg nanophase strengthening, and rare earth grain boundary purification, combined with low-burning smelting + rapid solidification + multi-stage heat treatment process. It can be widely used in aerospace high-temperature components, marine engineering corrosion-resistant structural parts, high-end die-casting molds, and other fields, filling the gap in existing copper alloy technology.

Description

Technical Field

[0001] The present invention belongs to the technical field of alloys, and in particular relates to a copper alloy and a preparation method and application thereof. Background Art

[0002] Copper alloys are widely used in power electronics, aerospace, marine engineering, high-temperature molds and other fields due to their excellent electrical and thermal conductivity, corrosion resistance and processing properties. However, with the increasing complexity of industrial environments (such as high temperature, high humidity, sulfur / chlorine-containing media, etc.), the limitations of traditional copper alloys are becoming increasingly prominent, mainly reflected in the following aspects:

[0003] 1. High-temperature oxidation and insufficient strength: Ordinary pure copper and brass (Cu-Zn series) undergo significant oxidation softening above 200°C, resulting in a sharp drop in high-temperature strength, making it difficult to meet the high-temperature stability requirements of engine components, die-casting molds, etc. Although aluminum bronze (Cu-Al series) increases its oxidation resistance to around 500°C through an Al2O3 film, its high aluminum content (>10%) degrades its processing performance and its resistance to sulfidation corrosion is insufficient.

[0004] 2. Limitations in corrosion resistance: Existing corrosion-resistant copper alloys (such as white copper Cu-Ni series and beryllium copper Cu-Be series) have obvious defects in specific environments. For example, white copper is prone to sulfidation corrosion in sulfur-containing media, and although beryllium copper has high strength and high conductivity, the beryllium element is highly toxic and the processing and waste disposal costs are high. In addition, brass is prone to dezincification corrosion in seawater environments, and aluminum bronze has insufficient corrosion resistance in acidic media, which limits their application range.

[0005] 3. Insufficient synergistic effect of multiple components: In recent years, there has been an increasing number of studies on improving the performance of copper alloys by adding elements such as Cr, Ni, and Si, but the selection and proportioning of elements lack systematic optimization. For example, the prior art discloses a Cu-Cr-Zr alloy, which has a certain high-temperature strength, but does not introduce oxide film-forming elements such as Al and Si, resulting in an insufficient upper limit of the oxidation resistance temperature; the prior art also discloses a Cu-Ni-Si-Mg alloy, which improves corrosion resistance, but does not consider the effect of rare earth elements on grain boundary purification, and has low high-temperature creep resistance. In addition, the addition of elements in the prior art is mostly limited to 3-4 types, which makes it difficult to take into account the synergistic improvement of high-temperature strength, corrosion resistance and processing performance.

[0006] 4. Preparation process defects: During traditional copper alloy smelting, highly active elements (such as Mg and Zr) are easily oxidized and burned, leading to composition deviations and performance fluctuations. For example, CN110616361A uses non-vacuum smelting to prepare Zr-containing copper alloys. Due to severe Zr oxidation losses, the actual Zr content is difficult to accurately control. Insufficient casting cooling rates can lead to significant grain coarsening and segregation, affecting material homogeneity.

[0007] To address the above problems, it is urgent to develop a new type of multi-component copper alloy. By scientifically designing the element composition and proportions and combining them with efficient preparation processes, we can break through the bottlenecks of high-temperature strength, resistance to complex media corrosion and processing performance while maintaining high thermal conductivity and electrical conductivity, and meet the urgent demand for high-performance copper alloys in the field of high-end equipment manufacturing. Summary of the Invention

[0008] In view of the above-mentioned prior art, the present invention provides a copper alloy and a preparation method and application thereof, so as to solve the technical problem that the existing copper alloy has poor comprehensive performance.

[0009] In order to achieve the above object, the technical solution adopted by the present invention is to provide a copper alloy, which includes the following components in mass percentage:

[0010] Cu 50-60%, Al 1-3%, Cr 0.5-2%, Zr 0.05-0.2%, Ni 2-5%, Mg 0.1-0.3%, Ti 0.5-2%, Si 0.5-1%, rare earth elements 0.02-0.05%, and the balance is zinc.

[0011] On the basis of the above technical solution, the present invention can also be improved as follows.

[0012] Furthermore, the copper alloy includes the following components in percentage by mass:

[0013] Cu 58%, Al 2%, Cr 1.3%, Zr 0.13%, Ni 3%, Mg 0.2%, Ti 1%, Si 0.7%, rare earth elements 0.03%, and the balance is zinc.

[0014] Furthermore, the rare earth element is at least one of Y, Sc, Ce and La.

[0015] The present invention also discloses a method for preparing the copper alloy, comprising the following steps:

[0016] S1: Place electrolytic copper, Cu-Cr master alloy, Cu-Zr master alloy and Cu-Ni master alloy into the vacuum induction melting furnace according to the proportion of elements, and evacuate the vacuum induction melting furnace to ≤10 -2 Pa, then fill with argon; then heat to 1250-1300℃, smelt for 20-30min to obtain metal base liquid;

[0017] S2: Cool the metal base liquid to 1150°C, then add Cu-Al master alloy and Cu-Si master alloy according to the element ratio, keep warm and stir for 5 minutes; then heat it to 1250-1300°C, add pure Ti particles according to the element ratio, stir until completely melted, and obtain the master alloy liquid;

[0018] S3: Cool the master alloy liquid to 1150°C, then add pure Mg foil and Cu-Re master alloy according to the element ratio, keep warm and stir for 3-5 minutes, then add Zn particles according to the element ratio, continue to keep warm and stir for 3 minutes, and then keep warm and let stand for 5 minutes;

[0019] S4: The temperature of the alloy liquid obtained in S3 is lowered to 1000-1050°C, and then a refining agent is added. The mixture is stirred at this temperature for 3 minutes, and then allowed to stand for 10 minutes to remove the surface slag to obtain a pourable alloy liquid.

[0020] S5: adjusting the temperature of the alloying liquid to 1080-1120° C., then pouring it into a mold at a pouring speed of 0.5-1 kg / s, and then water-cooling it to room temperature to obtain an alloy ingot;

[0021] S6: heating the alloy ingot to 850-900°C in an inert atmosphere and keeping the temperature for 6-12 hours; then cooling it to 500°C with the furnace and then air cooling it to room temperature;

[0022] S7: The ingot after S6 treatment is heated to 850-900°C and kept at this temperature for 2 hours; then hot rolling is performed, with the total deformation of the hot rolling being 60-80%, the deformation of each pass being 10-15%, and the final temperature of the hot rolling being 750°C; then forging is performed by upsetting + drawing, with the cumulative deformation of the forging being ≥70%; then air cooling is performed to room temperature to obtain a forged piece;

[0023] S8: Heat the forged piece to 900-950°C, keep it at that temperature for 1-2 hours, and then water quench it; then heat the water-quenched forging piece to 450-550°C, keep it at that temperature for 4-8 hours, and then air-cool it to room temperature.

[0024] Furthermore, the cooling rates in S2, S3 and S4 are all 10-15°C / min.

[0025] Furthermore, the refining agent is hexachloroethane.

[0026] Furthermore, the amount of refining agent added is 0.1% of the mass of the alloy liquid.

[0027] Furthermore, the water cooling rate in S5 is 50-70°C / s.

[0028] Furthermore, the heating rates in S6, S7 and S8 are all 10-15°C / min.

[0029] The invention also discloses the application of the copper alloy in manufacturing high-temperature resistant metal parts.

[0030] The beneficial effects of the present invention are:

[0031] 1. The copper alloy element composition of the present invention is Cu-Al-Cr-Zr-Ni-Mg-Ti-Si-rare earth-Zn, wherein Al is preferentially oxidized to form α-Al2O3 (dense layer) at high temperature, which inhibits the diffusion of oxygen into the alloy; Cr is oxidized to form Cr2O3, which fills the cracks in the Al2O3 film and improves the continuity of the oxide film; Si is oxidized to form a SiO2 glassy layer, which covers the surface pores and reduces the risk of oxide film peeling; the three oxide films work together to reduce the oxidation rate of the alloy at a high temperature of 500-800°C to ≤0.1g / (m 2 h), an improvement of over 50% compared to traditional aluminum bronze (C95400). The nickel in the alloy inhibits sulfidation corrosion (forming Ni3S2 instead of Cu2S with sulfur), giving the alloy excellent resistance to sulfidation corrosion. Cr blocks chloride ion penetration, giving the alloy excellent resistance to chloride ion corrosion. Ni and Cr, dissolved in the alloy matrix, increase the interatomic bonding energy, thereby delaying high-temperature softening and improving the alloy's deformation resistance. Zr in the alloy forms nanoscale (20-50nm) Cu5Zr with Cu, pinning dislocations. Ti combines with Al to form TiAl3 precipitates (≤30nm), which inhibit high-temperature grain boundary sliding. This results in a room-temperature tensile strength of 650-800MPa, a tensile strength of ≥400MPa at 500°C, and a high-temperature strength retention rate of ≥60% at 500°C, making it suitable for repeated thermal shock environments (such as die-casting molds). Furthermore, Zr refines the grain size, effectively reducing thermal stress concentration. Mg in the alloy can inhibit grain boundary segregation, while rare earth can purify the grain boundaries. The two work together to improve the plasticity of the alloy and give the alloy chamber excellent molding properties.

[0032] 2. When preparing copper alloy, the present invention adopts vacuum melting + intermediate alloy pre-melting to prepare the metal base liquid, which can control the burn-out rate of active elements (Zr, Mg, etc.) to below 3% (the burn-out rate of traditional non-vacuum melting is >10%), ensuring the uniformity of the composition; in the present invention, after the alloy is poured, it is cooled by extremely fast water cooling (cooling rate ≥50°C / s), and rapid solidification can effectively inhibit dendrite growth. The grain size of the final alloy is ≤50μm, the cast porosity is ≤0.5%, and the internal segregation of the alloy can be eliminated through homogenization annealing + solid solution + aging treatment. The defect rate of the obtained alloy is low, thus having excellent comprehensive performance.

[0033] 3. The copper alloy in the present invention has achieved a breakthrough improvement in high-temperature strength, resistance to complex corrosion, processing performance and environmental protection through innovative designs such as Al-Cr-Si oxide film synergistic protection, Zr-Ti-Mg nanophase strengthening, and rare earth grain boundary purification, combined with low-burning smelting + rapid solidification + multi-stage heat treatment process. It can be widely used in aerospace high-temperature components, marine engineering corrosion-resistant structural parts, high-end die-casting molds and other fields, filling the gap in existing copper alloy technology. DETAILED DESCRIPTION

[0034] The specific implementation methods of the present invention are described in detail below with reference to the embodiments.

[0035] Example 1

[0036] A copper alloy comprising the following components in percentage by mass:

[0037] Cu 58%, Al 2%, Cr 1.3%, Zr 0.13%, Ni 3%, Mg 0.2%, Ti 1%, Si 0.7%, Y 0.03%, and the balance is zinc.

[0038] The copper alloy in this embodiment is prepared by the following steps:

[0039] S1: Place electrolytic copper, Cu-Cr master alloy, Cu-Zr master alloy and Cu-Ni master alloy into the vacuum induction melting furnace according to the proportion of elements, and evacuate the vacuum induction melting furnace to ≤10 -2 Pa, argon gas was filled in; then the temperature was raised to 1300℃ and smelted for 25min to obtain the metal base liquid;

[0040] S2: Cool the metal base liquid to 1150°C at a cooling rate of 10°C / min, then add Cu-Al master alloy and Cu-Si master alloy according to the element ratio, keep warm and stir for 5 minutes; then heat to 1300°C, add pure Ti particles according to the element ratio, and stir until completely dissolved to obtain a master alloy liquid;

[0041] S3: Cool the master alloy liquid to 1150°C at a cooling rate of 10°C / min, then add pure Mg foil and Cu-Y master alloy according to the element ratio, keep warm and stir for 3 minutes, then add Zn particles according to the element ratio, continue to keep warm and stir for 3 minutes, and then keep warm and stand for 5 minutes;

[0042] S4: The temperature of the alloy liquid obtained in S3 was lowered to 1050°C at a cooling rate of 10°C / min, and then hexachloroethane (0.1% of the mass of the alloy liquid) was added. The mixture was stirred at this temperature for 3 minutes, and then allowed to stand for 10 minutes to remove the surface slag to obtain a castable alloy liquid.

[0043] S5: adjusting the temperature of the alloying liquid to 1110° C., then pouring it into a mold at a pouring rate of 0.5 kg / s, and then water-cooling it to room temperature at a rate of 60° C. / s to obtain an alloy ingot;

[0044] S6: heating the alloy ingot to 900°C at a heating rate of 10°C / min in a nitrogen atmosphere and holding the temperature for 10 hours; then cooling the ingot to 500°C in the furnace and then air cooling it to room temperature;

[0045] S7: The ingot treated in S6 is heated to 900°C at a heating rate of 10°C / min and kept at this temperature for 2 hours; then hot rolling is performed with a total deformation of 70%, a deformation per pass of 12%, and a final temperature of 750°C; then forging is performed by upsetting and drawing, with a cumulative deformation of ≥70%; then air cooling is performed to room temperature to obtain a forged piece;

[0046] S8: Heat the forged piece to 920°C at a heating rate of 10°C / min, keep it at that temperature for 1.5 hours, and then water quench it; then heat the water-quenched forging piece to 500°C, keep it at that temperature for 6 hours, and then air-cool it to room temperature.

[0047] Example 2

[0048] A copper alloy comprising the following components in percentage by mass:

[0049] Cu 50%, Al 3%, Cr 0.5%, Zr 0.2%, Ni 2%, Mg 0.3%, Ti 0.5%, Si 1%, Ce 0.02%, and the balance is zinc.

[0050] The copper alloy in this embodiment is prepared by the following steps:

[0051] S1: Place electrolytic copper, Cu-Cr master alloy, Cu-Zr master alloy and Cu-Ni master alloy into the vacuum induction melting furnace according to the proportion of elements, and evacuate the vacuum induction melting furnace to ≤10 -2 Pa, argon gas was filled in; then the temperature was raised to 1250℃ and smelted for 30min to obtain the metal base liquid;

[0052] S2: Cool the metal base liquid to 1150°C at a cooling rate of 10°C / min, then add Cu-Al master alloy and Cu-Si master alloy according to the element ratio, keep warm and stir for 5 minutes; then heat to 1250°C, add pure Ti particles according to the element ratio, and stir until completely dissolved to obtain a master alloy liquid;

[0053] S3: Cool the master alloy liquid to 1150°C at a cooling rate of 10°C / min, then add pure Mg foil and Cu-Ce master alloy according to the element ratio, keep warm and stir for 3 minutes, then add Zn particles according to the element ratio, continue to keep warm and stir for 3 minutes, and then keep warm and stand for 5 minutes;

[0054] S4: Cool the alloy liquid obtained in S3 to 1000°C at a cooling rate of 10°C / min, then add hexachloroethane (0.1% of the mass of the alloy liquid), keep stirring for 3 minutes, and then let it stand for 10 minutes to remove the surface slag to obtain a pourable alloy liquid;

[0055] S5: adjusting the temperature of the alloying liquid to 1080° C., then pouring it into a mold at a pouring rate of 0.5 kg / s, and then water-cooling it to room temperature at a rate of 50° C. / s to obtain an alloy ingot;

[0056] S6: heating the alloy ingot to 850°C at a heating rate of 10°C / min in a nitrogen atmosphere and holding the temperature for 12 hours; then cooling the ingot to 500°C in the furnace and then air cooling it to room temperature;

[0057] S7: The ingot treated in S6 is heated to 850°C at a heating rate of 10°C / min and kept at this temperature for 2 hours; then hot rolling is performed with a total deformation of 60% and a deformation per pass of 10% at a final temperature of 750°C; then forging is performed by upsetting and drawing with a cumulative deformation of ≥70%; then air cooling is performed to room temperature to obtain a forged piece;

[0058] S8: Heat the forged piece to 900°C at a heating rate of 10°C / min, keep it at that temperature for 2 hours, and then water quench it; then heat the water-quenched forging piece to 450°C, keep it at that temperature for 8 hours, and then air-cool it to room temperature.

[0059] Example 3

[0060] A copper alloy comprising the following components in percentage by mass:

[0061] Cu 60%, Al 1%, Cr 2%, Zr 0.05%, Ni 5%, Mg 0.1%, Ti 2%, Si 0.5%, Ce 0.03%, La 0.02%, and the balance is zinc.

[0062] The copper alloy in this embodiment is prepared by the following steps:

[0063] S1: Place electrolytic copper, Cu-Cr master alloy, Cu-Zr master alloy and Cu-Ni master alloy into the vacuum induction melting furnace according to the proportion of elements, and evacuate the vacuum induction melting furnace to ≤10 -2 Pa, argon gas was filled in; then the temperature was raised to 1300℃ and smelted for 30min to obtain the metal base liquid;

[0064] S2: Cool the metal base liquid to 1150°C at a cooling rate of 15°C / min, then add Cu-Al master alloy and Cu-Si master alloy according to the element ratio, keep warm and stir for 5 minutes; then heat it to 1300°C, add pure Ti particles according to the element ratio, and stir until completely dissolved to obtain a master alloy liquid;

[0065] S3: Cool the master alloy liquid to 1150°C at a cooling rate of 15°C / min, then add pure Mg foil, Cu-Ce master alloy, and Cu-La master alloy according to the element ratio, keep warm and stir for 3 minutes, then add Zn particles according to the element ratio, continue to keep warm and stir for 3 minutes, and then keep warm and stand for 5 minutes;

[0066] S4: Cool the alloy liquid obtained in S3 to 1050°C at a cooling rate of 15°C / min, then add hexachloroethane (0.1% of the mass of the alloy liquid), keep stirring for 3 minutes, and then let it stand for 10 minutes to remove the surface slag to obtain a pourable alloy liquid;

[0067] S5: adjusting the temperature of the alloying liquid to 1120° C., then pouring it into a mold at a pouring rate of 1 kg / s, and then water-cooling it to room temperature at a rate of 70° C. / s to obtain an alloy ingot;

[0068] S6: In a nitrogen atmosphere, the alloy ingot was heated to 900°C at a heating rate of 15°C / min and kept at this temperature for 6 hours; then, the ingot was furnace cooled to 500°C and then air-cooled to room temperature;

[0069] S7: The ingot treated in S6 is heated to 900°C at a heating rate of 15°C / min and kept at this temperature for 2 hours; then hot rolling is performed with a total deformation of 80% and a deformation per pass of 15% at a final temperature of 750°C; then forging is performed by upsetting and drawing with a cumulative deformation of ≥70%; then air cooling is performed to room temperature to obtain a forged piece;

[0070] S8: Heat the forging to 950°C at a heating rate of 15°C / min, keep it at that temperature for 1 hour, and then water quench it; then heat the water-quenched forging to 550°C, keep it at that temperature for 4 hours, and then air-cool it to room temperature.

[0071] Comparative Example 1

[0072] A copper alloy comprising the following components in percentage by mass:

[0073] Cu 59.3%, Al 2%, Zr 0.13%, Ni 3%, Mg 0.2%, Ti 1%, Si 0.7%, Y 0.03%, and the balance is zinc.

[0074] The copper alloy in this comparative example was prepared by the following steps:

[0075] S1: Place electrolytic copper, Cu-Zr master alloy, and Cu-Ni master alloy into a vacuum induction melting furnace according to the proportion of the elements, and evacuate the vacuum induction melting furnace to ≤10 -2 Pa, argon gas was filled in; then the temperature was raised to 1300℃ and smelted for 25min to obtain the metal base liquid;

[0076] S2: Cool the metal base liquid to 1150°C at a cooling rate of 10°C / min, then add Cu-Al master alloy and Cu-Si master alloy according to the element ratio, keep warm and stir for 5 minutes; then heat to 1300°C, add pure Ti particles according to the element ratio, and stir until completely dissolved to obtain a master alloy liquid;

[0077] S3: Cool the master alloy liquid to 1150°C at a cooling rate of 10°C / min, then add pure Mg foil and Cu-Y master alloy according to the element ratio, keep warm and stir for 3 minutes, then add Zn particles according to the element ratio, continue to keep warm and stir for 3 minutes, and then keep warm and stand for 5 minutes;

[0078] S4: The temperature of the alloy liquid obtained in S3 was lowered to 1050°C at a cooling rate of 10°C / min, and then hexachloroethane (0.1% of the mass of the alloy liquid) was added. The mixture was stirred at this temperature for 3 minutes, and then allowed to stand for 10 minutes to remove the surface slag to obtain a castable alloy liquid.

[0079] S5: adjusting the temperature of the alloying liquid to 1110° C., then pouring it into a mold at a pouring rate of 0.5 kg / s, and then water-cooling it to room temperature at a rate of 60° C. / s to obtain an alloy ingot;

[0080] S6: heating the alloy ingot to 900°C at a heating rate of 10°C / min in a nitrogen atmosphere and holding the temperature for 10 hours; then cooling the ingot to 500°C in the furnace and then air cooling it to room temperature;

[0081] S7: The ingot treated in S6 is heated to 900°C at a heating rate of 10°C / min and kept at this temperature for 2 hours; then hot rolling is performed with a total deformation of 70%, a deformation per pass of 12%, and a final temperature of 750°C; then forging is performed by upsetting and drawing, with a cumulative deformation of ≥70%; then air cooling is performed to room temperature to obtain a forged piece;

[0082] S8: Heat the forged piece to 920°C at a heating rate of 10°C / min, keep it at that temperature for 1.5 hours, and then water quench it; then heat the water-quenched forging piece to 500°C, keep it at that temperature for 6 hours, and then air-cool it to room temperature.

[0083] Comparative Example 2

[0084] A copper alloy comprising the following components in percentage by mass:

[0085] Cu 59.13%, Al 2%, Cr 1.3%, Ni 3%, Mg 0.2%, Si 0.7%, Y 0.03%, and the balance is zinc.

[0086] The copper alloy in this comparative example was prepared by the following steps:

[0087] S1: Place electrolytic copper, Cu-Cr master alloy and Cu-Ni master alloy into the vacuum induction melting furnace according to the proportion of elements, and evacuate the vacuum induction melting furnace to ≤10 -2 Pa, argon gas was filled in; then the temperature was raised to 1300℃ and smelted for 25min to obtain the metal base liquid;

[0088] S2: Cool the metal base liquid to 1150°C at a cooling rate of 10°C / min, then add Cu-Al master alloy and Cu-Si master alloy according to the element ratio, keep warm and stir for 5 minutes to obtain the master alloy liquid;

[0089] S3: Cool the master alloy liquid to 1150°C at a cooling rate of 10°C / min, then add pure Mg foil and Cu-Y master alloy according to the element ratio, keep warm and stir for 3 minutes, then add Zn particles according to the element ratio, continue to keep warm and stir for 3 minutes, and then keep warm and stand for 5 minutes;

[0090] S4: The temperature of the alloy liquid obtained in S3 was lowered to 1050°C at a cooling rate of 10°C / min, and then hexachloroethane (0.1% of the mass of the alloy liquid) was added. The mixture was stirred at this temperature for 3 minutes, and then allowed to stand for 10 minutes to remove the surface slag to obtain a castable alloy liquid.

[0091] S5: adjusting the temperature of the alloying liquid to 1110° C., then pouring it into a mold at a pouring rate of 0.5 kg / s, and then water-cooling it to room temperature at a rate of 60° C. / s to obtain an alloy ingot;

[0092] S6: heating the alloy ingot to 900°C at a heating rate of 10°C / min in a nitrogen atmosphere and holding the temperature for 10 hours; then cooling the ingot to 500°C in the furnace and then air cooling it to room temperature;

[0093] S7: The ingot treated in S6 is heated to 900°C at a heating rate of 10°C / min and kept at this temperature for 2 hours; then hot rolling is performed with a total deformation of 70%, a deformation per pass of 12%, and a final temperature of 750°C; then forging is performed by upsetting and drawing, with a cumulative deformation of ≥70%; then air cooling is performed to room temperature to obtain a forged piece;

[0094] S8: Heat the forged piece to 920°C at a heating rate of 10°C / min, keep it at that temperature for 1.5 hours, and then water quench it; then heat the water-quenched forging piece to 500°C, keep it at that temperature for 6 hours, and then air-cool it to room temperature.

[0095] Comparative Example 3

[0096] A copper alloy comprising the following components in percentage by mass:

[0097] Cu 58%, Al 2%, Cr 1.3%, Zr 0.13%, Ni 3%, Mg 0.2%, Ti 1%, Si 0.7%, Y 0.03%, and the balance is zinc.

[0098] The copper alloy in this comparative example was prepared by the following steps:

[0099] S1: electrolytic copper, Cu-Cr master alloy, Cu-Zr master alloy, and Cu-Ni master alloy are charged into a smelting furnace according to the proportion of elements, heated to 1300°C, and smelted for 25 minutes to obtain a metal base liquid;

[0100] S2: Cool the metal base liquid to 1150°C at a cooling rate of 10°C / min, then add Cu-Al master alloy and Cu-Si master alloy according to the element ratio, keep warm and stir for 5 minutes; then heat to 1300°C, add pure Ti particles according to the element ratio, and stir until completely dissolved to obtain a master alloy liquid;

[0101] S3: Cool the master alloy liquid to 1150°C at a cooling rate of 10°C / min, then add pure Mg foil and Cu-Y master alloy according to the element ratio, keep warm and stir for 3 minutes, then add Zn particles according to the element ratio, continue to keep warm and stir for 3 minutes, and then keep warm and stand for 5 minutes;

[0102] S4: The temperature of the alloy liquid obtained in S3 was lowered to 1050°C at a cooling rate of 10°C / min, and then hexachloroethane (0.1% of the mass of the alloy liquid) was added. The mixture was stirred at this temperature for 3 minutes, and then allowed to stand for 10 minutes to remove the surface slag to obtain a castable alloy liquid.

[0103] S5: adjusting the temperature of the alloying liquid to 1110° C., then pouring it into a mold at a pouring rate of 0.5 kg / s, and then air-cooling it to room temperature to obtain an alloy ingot;

[0104] S6: In a nitrogen atmosphere, the alloy ingot is heated to 900°C at a heating rate of 10°C / min and kept at this temperature for 10 hours; then, the alloy ingot is furnace cooled to 500°C and then air-cooled to room temperature.

[0105] Experimental example

[0106] The high-temperature oxidation performance of the copper alloys prepared in the above embodiments and comparative examples was tested using the method described in GB / T 13303-1991, and the room-temperature tensile strength of the copper alloy was tested using the method described in GB / T 228.1-2021. The results are shown in Table 1.

[0107] Table 1 High temperature oxidation properties and room temperature tensile strength of copper alloys

[0108] Maximum antioxidant temperature (℃) Room temperature tensile strength (MPa) Example 1 804 793 Example 2 793 764 Example 3 798 772 Comparative Example 1 684 699 Comparative Example 2 607 603 Comparative Example 3 711 704

[0109] Although the specific embodiments of the present invention have been described in detail in conjunction with the embodiments, this should not be construed as limiting the scope of protection of this patent. Within the scope described by the claims, various modifications and variations that can be made by those skilled in the art without creative work still fall within the scope of protection of this patent.

Claims

1. A copper alloy, characterized in that The copper alloy is used to make high-temperature resistant metal parts; the copper alloy includes the following components in percentage by mass: Cu 50~60%, Al 1~3%, Cr 0.5~2%, Zr 0.05~0.2%, Ni 2~5%, Mg 0.1~0.3%, Ti 0.5~2%, Si0.5~1%, rare earth elements 0.02~0.05%, balance zinc; The copper alloy is prepared by the following steps: S1: Place electrolytic copper, Cu-Cr master alloy, Cu-Zr master alloy and Cu-Ni master alloy into the vacuum induction melting furnace according to the proportion of elements, and evacuate the vacuum induction melting furnace to ≤10 -2 Pa, then fill with argon; then heat to 1250~1300℃, smelt for 20~30min to obtain metal base liquid; S2: Cool the metal base liquid to 1150°C, then add Cu-Al master alloy and Cu-Si master alloy according to the element ratio, keep warm and stir for 5 minutes; then heat it to 1250-1300°C, add pure Ti particles according to the element ratio, stir until completely melted, and obtain the master alloy liquid; S3: Cool the master alloy liquid to 1150°C, then add pure Mg foil and Cu-RE master alloy according to the element ratio, keep warm and stir for 3-5 minutes, then add Zn particles according to the element ratio, continue to keep warm and stir for 3 minutes, and then keep warm and let it stand for 5 minutes; S4: Lower the temperature of the alloy liquid obtained in S3 to 1000-1050°C, then add a refining agent, keep the mixture warm and stir for 3 minutes, then let it stand for 10 minutes, remove the surface slag, and obtain a pourable alloy liquid; S5: adjusting the temperature of the alloying liquid to 1080-1120° C., then pouring it into a mold at a pouring speed of 0.5-1 kg / s, and then water-cooling it to room temperature to obtain an alloy ingot; S6: In an inert atmosphere, heat the alloy ingot to 850-900°C and keep it at this temperature for 6-12 hours; then cool it to 500°C in the furnace and then air cool it to room temperature; S7: heating the ingot after S6 treatment to 850-900°C and keeping the temperature for 2 hours; Then hot rolling is carried out, with the total deformation of hot rolling being 60-80%, the deformation of each pass being 10-15%, and the final temperature of hot rolling being 750°C; then forging is carried out by upsetting + drawing, with the cumulative deformation of forging being ≥70%; then air cooling is carried out to room temperature to obtain forgings; S8: Heat the forging to 900-950°C, keep it warm for 1-2 hours, and then water quench it; then heat the quenched forging to 450-550°C, keep it warm for 4-8 hours, and then air-cool it to room temperature.

2. The copper alloy according to claim 1, characterized in that The copper alloy includes the following components in percentage by mass: Cu 58%, Al 2%, Cr 1.3%, Zr 0.13%, Ni 3%, Mg 0.2%, Ti 1%, Si 0.7%, rare earth elements 0.03%, and the balance is zinc.

3. The copper alloy according to claim 1 or 2, characterized in that: The rare earth element is at least one of Y, Sc, Ce and La.

4. The copper alloy according to claim 1, wherein: The cooling rates in S2, S3 and S4 are all 10~15℃ / min.

5. The copper alloy according to claim 1, wherein: The refining agent is hexachloroethane.

6. The copper alloy according to claim 5, characterized in that: The amount of the refining agent added is 0.1% of the mass of the alloy liquid.

7. The copper alloy according to claim 1, wherein: The water cooling rate in S5 is 50~70℃ / s.

8. The copper alloy according to claim 1, wherein: The heating rates in S6, S7 and S8 were all 10-15°C / min.