High-heat-resistance and high-conductivity copper alloy and preparation method thereof

Abstract

The invention discloses a copper alloy with high heat resistance and high conductivity. The copper alloy comprises the following components in percentage by weight: 0.1 to 1.5 percent of Cr, 0.01 to 0.5 percent of Ti, 0.01 to 0.5 percent of Zn, 0.01 to 0.5 percent of Sn, 0.01 to 0.5 percent of Si, 0.01 to 0.5 percent of Nb, 0.01 to 0.5 percent of Fe, 0.01 to 0.2 percent of Co and the balance of Cu and inevitable impurities. The preparation method comprises the following steps: melting a copper source, a chromium source, a titanium source, a zinc source, a tin source, a silicon source, a niobium source, an iron source and a cobalt source in a heating furnace to obtain an alloy melt; and the alloy melt is subjected to up-drawing method continuous casting, heating and heat preservation, continuous rolling, cold rolling deformation, aging treatment, finish rolling treatment and stress relief annealing treatment, and the high-heat-resistance and high-conductivity copper alloy is obtained. The high-heat-resistance and high-conductivity copper alloy is excellent in strength and conductivity.

Description

Technical Field

[0001] The invention belongs to the field of alloy materials, and in particular relates to a high-heat-resistant and high-conductivity copper alloy and a preparation method thereof. Background Art

[0002] Highly heat-resistant and highly conductive copper alloys are a type of copper-based material with excellent conductivity and heat resistance. They are widely used in electronics, electrical, aviation, aerospace, rail transportation and other fields.

[0003] The patent application with application number 202010385096.3 discloses a method for preparing copper alloys by powder metallurgy, which includes smelting raw materials, spraying powder by inert gas atomization, sintering by SPS in a reducing atmosphere, hot rolling or hot extrusion, cold rolling or cold drawing, and finally annealing and passivation to obtain a high heat-resistant and high-conductivity CuCrNb copper alloy. However, when preparing copper alloys by this method, the solid solubility of Cr in the system is low, and the performance improvement of the copper alloy is limited.

[0004] The patent application with application number 201910440747.1 discloses a method for preparing a high temperature resistant Cu-Cr-Nb-Ce alloy for the inner lining of the combustion chamber of an aircraft engine, which mainly includes the following steps: batching, vacuum induction melting, casting, electrode induction atomization and powder jacket hot extrusion. However, this method is expensive and not conducive to large-scale production. At the same time, the overall performance of the copper alloy prepared by this method is not good.

[0005] Based on this, it is necessary to study a high heat-resistant and high-conductivity copper alloy and its preparation method with simple production process, convenient operation, high alloy strength, good heat resistance and other excellent overall properties. Summary of the invention

[0006] The technical problem to be solved by the present invention is to overcome the deficiencies and defects mentioned in the above background technology and provide a high heat-resistant and high-conductivity copper alloy and a preparation method thereof.

[0007] In order to solve the above technical problems, the technical solution proposed by the present invention is:

[0008] A high heat-resistant and high-conductivity copper alloy, wherein the composition of the high heat-resistant and high-conductivity copper alloy comprises, by mass percentage:

[0009] Cr: 0.1-1.5%, Ti: 0.01-0.5%, Zn: 0.01-0.5%, Sn: 0.01-0.5%, Si: 0.01-0.5%, Nb: 0.01-0.5%, Fe: 0.01-0.5%, Co: 0.01-0.2%, the balance Cu and inevitable impurities.

[0010] The above-mentioned high heat-resistant and high-conductivity copper alloy is preferably composed of, in terms of mass percentage, the following:

[0011] Cr: 0.8-1.0%, Ti: 0.2-0.3%, Zn: 0.1-0.2%, Sn: 0.1-0.2%, Si: 0.1-0.2%, Nb: 0.1-0.2%, Fe: 0.1-0.2%, Co: 0.1-0.15%, the balance is Cu and inevitable impurities.

[0012] In the copper alloy of the present invention, the addition of Cr element can provide aging strengthening effect and significantly improve the mechanical properties of the alloy; the addition of Ti element can promote the precipitation of Cr and inhibit the growth of Cr, thereby achieving the simultaneous improvement of the electrical conductivity, mechanical properties and heat resistance of the alloy; the addition of Zn element can provide solid solution strengthening effect and improve the mechanical properties of the alloy; the addition of Sn element can improve the distribution of the second phase in the alloy and improve the corrosion resistance of the alloy; Si, Nb, Fe, and Co elements can generate a variety of intermediate phase particles with stable structures in the matrix (such as Cu3Si, Cu4Ti, Cr2Si, Cr3Si, Cr2Nb, TiSi2, Co2Si, Co2Ti, Nb3Si, Fe2Si, Fe2Nb, Fe2Ti, etc.), and these intermediate phase particles are all beneficial to improving the heat resistance and high temperature performance of the alloy, and play a synergistic strengthening effect.

[0013] In the copper alloy of the present invention, the addition amount of Ti, Zn, Sn, Si, Fe, and Co elements also has a great influence on the electrical conductivity of the copper alloy. Adding an appropriate amount of alloying elements can promote the precipitation of Cr elements, inhibit the coarsening of Cr particles, and improve the precipitation strengthening effect and the electrical conductivity of the alloy. At the same time, the stable intermediate phase particles generated in the alloy improve the high-temperature mechanical properties and heat resistance of the alloy. Too few alloying elements will reduce the promotion effect on the precipitation of Cr elements and reduce the strengthening effect of the alloy; at the same time, fewer intermediate phase particles are formed in the alloy, and the particles contribute less to the high-temperature stability. Excessive alloying elements are likely to cause alloy component segregation and coarsening of the strengthening phase, reduce the mechanical properties of the alloy, and at the same time, excessive alloying elements increase the electron scattering of the matrix and thus reduce the electrical conductivity. Therefore, in order to ensure that the copper alloy has excellent electrical conductivity and heat resistance, the content of Cr, Ti, Zn, Sn, Si, Nb, Fe, and Co elements in the present invention needs to be maintained within the above range.

[0014] The above-mentioned high heat-resistant and high conductivity copper alloy, preferably, the high heat-resistant and high conductivity copper alloy, at room temperature, has an electrical conductivity of not less than 76.6% IACS, a tensile strength of not less than 517.3 MPa, and an elongation of not less than 12.6%; at 300°C, its tensile strength is not less than 237.5 MPa, and the elongation is not less than 13.1%; at 600°C, its tensile strength is not less than 216.4 MPa, and the elongation is not less than 13.6%.

[0015] As a general inventive concept, the present invention also provides a method for preparing the above-mentioned high heat-resistant and high-conductivity copper alloy, comprising the following steps:

[0016] (1) weighing a copper source, a chromium source, a titanium source, a zinc source, a tin source, a silicon source, a niobium source, an iron source, a cobalt source, etc. according to a mass ratio, and melting them in a heating furnace to obtain an alloy melt;

[0017] (2) performing an upward continuous casting process on the alloy melt to obtain a rod material;

[0018] (3) heating, keeping warm and continuously rolling the rod material to obtain a hot-rolled plate;

[0019] (4) The hot-rolled sheet is subjected to cold rolling deformation, aging treatment, finish rolling treatment and stress relief annealing treatment to obtain a high heat-resistant and high-conductivity copper alloy.

[0020] The excellent performance of copper-based alloys is based on the precipitation strengthening phase when Cr is added to copper alloys. After aging treatment, tiny dispersed Cr particles are formed in the copper matrix, which improves the strength of the alloy through precipitation strengthening. In high temperature environments, the fine Cr particles can prevent grain growth, thereby improving the thermal stability of the alloy. In addition, Cr itself has good corrosion resistance. In a corrosive environment, Cr can form dense oxides to improve the corrosion resistance of the alloy.

[0021] Since the room temperature solubility of Cr in copper matrix is ​​very low, the continuous casting by the upward method adopted in the present invention can effectively increase the solid solubility of Cr in copper matrix and improve the precipitation strengthening effect of the alloy in the subsequent treatment process; at the same time, the casting method greatly improves the production efficiency and is suitable for large-scale production. On the one hand, hot rolling combined with cold rolling can effectively eliminate the structural defects of the cast alloy, improve the distribution of elements and intermediate phases, and improve the dispersion strengthening effect of particles and the pinning effect of grain boundaries; on the other hand, it can effectively refine the grains of the copper matrix and improve the grain boundary strengthening effect of the alloy; in addition, rolling can effectively increase the dislocation density of the alloy, and dislocations can promote the precipitation of Cr as nucleation sites, and can also provide dislocation strengthening effects for the alloy; subsequent aging treatment provides significant precipitation strengthening effects. Therefore, the continuous casting by the upward method + hot rolling + cold rolling + aging treatment can achieve the improvement of the structure of the alloy, achieve the simultaneous improvement of mechanical properties, electrical conductivity, and heat resistance, and achieve a synergistic strengthening effect. Room temperature finishing rolling combined with stress relief annealing can achieve precise control of the size of the alloy product, and at the same time optimize the plasticity and toughness of the alloy.

[0022] In the above preparation method, preferably, in step (1), the copper source is pure copper, the chromium source is pure chromium or a copper-chromium alloy, the titanium source is pure titanium or a copper-titanium alloy, the zinc source is pure zinc or a copper-zinc alloy, the tin source is pure tin or a copper-tin alloy, the silicon source is pure silicon or a copper-silicon alloy, the niobium source is a copper-niobium alloy, the iron source is pure iron or a copper-iron alloy, and the cobalt source is pure cobalt or a copper-cobalt alloy.

[0023] In the above-mentioned preparation method, preferably, in step (1), the specific preparation process of the alloy melt includes: first adding a copper source to a heating furnace, and raising the temperature in the heating furnace to 1350-1450°C to melt the copper source, after the copper source is fully melted, adding a chromium source, a titanium source, a tin source, a silicon source, a niobium source, an iron source, and a cobalt source to the heating furnace for melting, and heating the melt to raise the temperature to 1500-1600°C, after the raw materials are completely melted, reducing the melt temperature to 1300-1350°C and adding a zinc source for smelting to obtain an alloy melt.

[0024] In the above preparation method, preferably, in step (2), the temperature of the upward continuous casting is 1300-1350°C, and the speed of the upward continuous casting is 3-5 mm / s.

[0025] In the above preparation method, preferably, in step (3), the heating and insulation temperature is 900-950°C, and the insulation time is 5-10 minutes; the continuous hot rolling temperature is 900-950°C, and the total hot rolling deformation is 60-90%.

[0026] In the above-mentioned preparation method, preferably, in step (4), the deformation amount of the cold rolling deformation is 40-80%, and the temperature of the rolling deformation is room temperature.

[0027] In the above-mentioned preparation method, preferably, in step (4), the temperature of the aging treatment is 300-500°C, and the time of the aging treatment is 0.5-4h; the finishing rolling treatment adopts room temperature finishing rolling treatment, and the finishing rolling deformation is controlled to be 3-5%; the temperature of the stress relief annealing treatment is 200-300°C, and the treatment time is 0.5-2h.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] (1) The high heat-resistant and high-conductivity copper alloy of the present invention contains Cr, Ti, Zn, Sn, Si, Nb, Fe and Co elements. The addition of Cr element can improve the strength and thermal stability of the copper-based alloy. The addition of Ti element can accelerate the precipitation of Cr phase particles and inhibit the coarsening of Cr particles, making the strength and conductivity of the copper-based alloy more excellent. Elements such as Si, Nb, Fe and Co can generate a variety of stable intermediate phase particles in the alloy, which is beneficial to increase the high-temperature stability of the copper alloy.

[0030] (2) The present invention adopts the upward continuous casting method to effectively improve the solid solubility of Cr in the copper matrix, which is beneficial to improving the precipitation strengthening effect of the alloy; compared with the traditional casting + solid solution treatment method, the upward continuous casting method is simple to operate, has high production efficiency, and is suitable for large-scale production.

[0031] (3) The present invention adopts hot rolling combined with cold rolling treatment to improve the copper alloy structure and the distribution of elements and intermediate phases, and enhance the dispersion strengthening effect of particles and the pinning effect of grain boundaries; on the other hand, it effectively refines the grains of the copper matrix, improves the dislocation density, grain boundary strengthening effect and dislocation strengthening effect of the alloy, and dislocations as nucleation sites can further promote the precipitation of Cr.

[0032] (4) The present invention adopts the upward continuous casting + hot rolling + cold rolling + aging treatment to achieve the improvement of the alloy structure and the optimization of performance, so as to achieve the simultaneous improvement of mechanical properties, electrical conductivity and heat resistance, and realize the synergistic strengthening effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a scanning electron microscope image of the high heat-resistant and high-conductivity copper alloy prepared in Example 1 of the present invention. DETAILED DESCRIPTION

[0034] In order to facilitate the understanding of the present invention, the present invention will be described more comprehensively and carefully in combination with preferred embodiments below, but the protection scope of the present invention is not limited to the following specific embodiments.

[0035] Unless otherwise defined, all professional terms used below have the same meanings as those generally understood by those skilled in the art. The professional terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the scope of protection of the present invention.

[0036] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in the present invention can be purchased from the market or prepared by existing methods.

[0037] Embodiment 1:

[0038] A high heat-resistant and high-conductivity copper alloy of the present invention comprises, by mass percentage:

[0039] Cr: 0.8%; Ti: 0.2%; Zn: 0.1%; Sn: 0.1%; Si: 0.1%; Nb: 0.1%; Fe: 0.1%; Co: 0.1%, the remainder is Cu and inevitable impurities, as shown in Table 1.

[0040] The method for preparing the high heat-resistant and high-conductivity copper alloy of this embodiment comprises the following steps:

[0041] (1) First, pure copper blocks are added to a heating furnace, and the temperature in the heating furnace is raised to 1350°C to melt the pure copper. After the copper is fully melted, pure chromium blocks, pure titanium blocks, pure tin blocks, pure silicon, copper-niobium alloy, pure iron blocks, and pure cobalt blocks are added to the heating furnace for melting, and the temperature is raised to 1500°C. After the raw materials are completely melted, the melt temperature is lowered to 1300°C and pure zinc is added for smelting. After smelting evenly, an alloy melt is formed.

[0042] (2) The alloy melt obtained in step (1) is subjected to upward continuous casting to obtain a rod material, wherein the upward continuous casting temperature is 1300° C. and the casting speed is 3 mm / s.

[0043] (3) The rod obtained after step (2) is heated to 900° C. and kept at this temperature for 5 minutes. After the heat preservation, continuous hot rolling is started. The continuous hot rolling temperature is 950° C. and the total hot rolling deformation is 60%.

[0044] (4) The hot-rolled sheet after step (3) is subjected to cold rolling deformation at room temperature, and the cold rolling deformation amount is 40%.

[0045] (5) The cold-rolled sheet after step (4) is subjected to aging treatment at a temperature of 300° C. and an aging treatment time of 4 h.

[0046] (6) The material after aging treatment in step (5) is subjected to room temperature finish rolling, and the finish rolling deformation is controlled at 3%.

[0047] (7) The plate after the finish rolling in step (6) is subjected to stress relief annealing, the annealing temperature is controlled to 200° C., and the annealing time is 2 h, and finally a high heat-resistant and high-conductivity copper alloy with uniform composition and excellent performance is obtained.

[0048] The scanning electron microscopy results of the alloy are shown in Figure 1 As shown, the particles with black and gray contrast in the figure are mesophase particles with a stable structure, and the size of the particles is less than 0.5 microns.

[0049] Embodiment 2:

[0050] A high heat-resistant and high-conductivity copper alloy of the present invention comprises, by mass percentage:

[0051] Cr: 0.9%; Ti: 0.2%; Zn: 0.15%; Sn: 0.15%; Si: 0.15%; Nb: 0.15%; Fe: 0.15%; Co: 0.1%, the remainder is Cu and inevitable impurities, as shown in Table 1.

[0052] The method for preparing the high heat-resistant and high-conductivity copper alloy of this embodiment comprises the following steps:

[0053] (1) First, pure copper blocks are added to a heating furnace, and the temperature in the heating furnace is raised to 1400°C to melt the pure copper. After the copper is fully melted, copper-chromium alloy blocks, copper-titanium alloy blocks, copper-tin alloy blocks, copper-silicon alloy blocks, copper-niobium alloy blocks, copper-iron alloy blocks, and copper-cobalt alloy blocks are added to the heating furnace for melting, and the temperature is raised to 1550°C. After the raw materials are completely melted, the melt temperature is lowered to 1300°C and copper-zinc alloy is added for smelting. After smelting evenly, an alloy melt is formed.

[0054] (2) The alloy melt obtained in step (1) is subjected to upward continuous casting to obtain a rod material, wherein the upward continuous casting temperature is 1300° C. and the casting speed is 4 mm / s.

[0055] (3) The rod obtained after step (2) is heated to 950° C. and kept at this temperature for 5 minutes. After the temperature is kept at this temperature, continuous hot rolling is started. The continuous hot rolling temperature is 900° C. and the total hot rolling deformation is 80%.

[0056] (4) The hot-rolled sheet after step (3) is subjected to cold rolling deformation at room temperature, and the cold rolling deformation amount is 60%.

[0057] (5) The cold-rolled sheet after step (4) is subjected to aging treatment at a temperature of 400° C. for 2 h.

[0058] (6) The material after aging treatment in step (5) is subjected to room temperature finish rolling, and the finish rolling deformation is controlled at 4%.

[0059] (7) The plate after the finish rolling in step (6) is subjected to stress relief annealing, the annealing temperature is controlled to be 250° C., and the annealing time is 1 hour, and finally a high heat-resistant and high-conductivity copper alloy with uniform composition and excellent performance is obtained.

[0060] Embodiment 3:

[0061] A high heat-resistant and high-conductivity copper alloy of the present invention comprises, by mass percentage:

[0062] Cr: 1.0%; Ti: 0.2%; Zn: 0.15%; Sn: 0.15%; Si: 0.15%; Nb: 0.15%; Fe: 0.15%; Co: 0.15%, the remainder is Cu and inevitable impurities, as shown in Table 1.

[0063] The method for preparing the high heat-resistant and high-conductivity copper alloy of this embodiment comprises the following steps:

[0064] (1) First, pure copper blocks are added to a heating furnace, and the temperature in the heating furnace is raised to 1450°C to melt the pure copper. After the copper is fully melted, pure chromium blocks, pure titanium blocks, pure tin blocks, pure silicon blocks, copper-niobium alloys, pure iron blocks, and pure cobalt blocks are added to the heating furnace for melting, and the temperature is raised to 1600°C. After the raw materials are completely melted, the melt temperature is lowered to 1350°C and pure zinc blocks are added for smelting. After smelting evenly, an alloy melt is formed.

[0065] (2) The alloy melt obtained in step (1) is subjected to upward continuous casting to obtain a rod material, wherein the upward continuous casting temperature is 1350° C. and the casting speed is 3 mm / s.

[0066] (3) The rod obtained after step (2) is heated to 950° C. and kept at this temperature for 10 minutes. After the temperature is kept at this temperature, continuous hot rolling is started. The continuous hot rolling temperature is 900° C. and the total hot rolling deformation is 80%.

[0067] (4) The hot-rolled sheet after step (3) is subjected to cold rolling deformation at room temperature, with the cold rolling deformation amount being 80%.

[0068] (5) The cold-rolled sheet after step (4) is subjected to aging treatment at a temperature of 500° C. and an aging treatment time of 0.5 h.

[0069] (6) The material after aging treatment in step (5) is subjected to room temperature finish rolling, and the deformation of the finish rolling is controlled to be 5%.

[0070] (7) The plate after the finish rolling in step (6) is subjected to stress relief annealing, the annealing temperature is controlled to be 250° C., and the annealing time is 1 hour, and finally a high heat-resistant and high-conductivity copper alloy with uniform composition and excellent performance is obtained.

[0071] Embodiment 4:

[0072] A high heat-resistant and high-conductivity copper alloy of the present invention comprises, by mass percentage:

[0073] Cr: 1.0%; Ti: 0.3%; Zn: 0.2%; Sn: 0.2%; Si: 0.2%; Nb: 0.2%; Fe: 0.2%; Co: 0.15%, the remainder is Cu and inevitable impurities, as shown in Table 1.

[0074] The method for preparing the high heat-resistant and high-conductivity copper alloy of this embodiment comprises the following steps:

[0075] (1) First, pure copper is added to a heating furnace, and the temperature in the heating furnace is raised to 1350°C to melt the pure copper. After the pure copper is fully melted, copper-chromium alloy, pure titanium, pure tin, pure silicon, copper-niobium alloy, copper-iron alloy, and pure cobalt are added to the heating furnace for melting, and the temperature is raised to 1600°C. After the raw materials are completely melted, the melt temperature is lowered to 1350°C and pure zinc is added for melting. After uniform melting, an alloy melt is formed.

[0076] (2) The alloy melt obtained in step (1) is subjected to upward continuous casting to obtain a rod material, wherein the upward continuous casting temperature is 1350° C. and the casting speed is 5 mm / s.

[0077] (3) The rod obtained after step (2) is heated to 950° C. and kept at this temperature for 10 minutes. After the temperature is kept at this temperature, continuous hot rolling is started. The continuous hot rolling temperature is 900° C. and the total hot rolling deformation is 90%.

[0078] (4) The hot-rolled sheet after step (3) is subjected to cold rolling deformation at room temperature, with the cold rolling deformation amount being 80%.

[0079] (5) The cold-rolled sheet after step (4) is subjected to aging treatment at a temperature of 500° C. and an aging treatment time of 0.5 h.

[0080] (6) The material after aging treatment in step (5) is subjected to room temperature finish rolling, and the deformation of the finish rolling is controlled to be 5%.

[0081] (7) The plate after the finish rolling in step (6) is subjected to stress relief annealing, the annealing temperature is controlled to 300° C., and the annealing time is 0.5 h, and finally a high heat-resistant and high-conductivity copper alloy with uniform composition and excellent performance is obtained.

[0082] Comparative Example 1:

[0083] The copper alloy of this comparative example has a composition content as shown in Table 1, which is the same as that of Example 1. The only difference between this comparative example and Example 1 is that no aging treatment is performed in the preparation method, that is, the aging treatment in step (5) is not performed in the preparation process, and the material after cold rolling deformation in step (4) is directly subjected to room temperature finish rolling. The other processes and parameters are exactly the same as those in Example 1.

[0084] Comparative Example 2:

[0085] The composition and content of the copper alloy in this comparative example are shown in Table 1. The difference between it and Example 2 is only that the amounts of titanium source, zinc source, tin source, silicon source, niobium source, iron source and cobalt source added in the preparation method are different, and the other processes and parameters are exactly the same as those in Example 2.

[0086] Comparative Example 3:

[0087] The copper alloy of this comparative example, whose composition contents are shown in Table 1, does not contain Ti, Zn, Sn, Si, Nb, Fe, and Co elements. The only difference between it and Example 3 is that no titanium source, zinc source, tin source, silicon source, niobium source, iron source, and cobalt source are added in the preparation method, and its preparation process is the same as that of Example 3.

[0088] Comparative Example 4:

[0089] The copper alloy of this comparative example has its component contents shown in Table 1, which are the same as those of Example 3. The difference between its preparation process and that of Example 3 lies in the different process conditions for aging treatment in step (5). In this comparative example, the aging treatment temperature is 250° C., the aging treatment time is 0.2 h, and the other processes and conditions are the same as those of Example 3.

[0090] Comparative Example 5:

[0091] The copper alloy of this comparative example has its component contents shown in Table 1, which are the same as those of Example 3. The difference between its preparation process and that of Example 3 is that the hot-rolled plate after step (3) is not subjected to room temperature cold rolling but directly subjected to aging treatment, room temperature finish rolling, and stress relief annealing. The other processes and conditions are the same as those of Example 3.

[0092] Table 1 Component contents of copper alloys in various embodiments and comparative examples (wt.%)

[0093] Cu Cr Ti Zn Sn Si Nb Fe Co Example 1 margin 0.8 0.2 0.1 0.1 0.1 0.1 0.1 0.1 Example 2 margin 0.9 0.2 0.15 0.15 0.15 0.15 0.15 0.1 Example 3 margin 1.0 0.2 0.15 0.15 0.15 0.15 0.15 0.15 Example 4 margin 1.0 0.3 0.2 0.2 0.2 0.2 0.2 0.15 Comparative Example 1 margin 0.8 0.2 0.1 0.1 0.1 0.1 0.1 0.1 Comparative Example 2 margin 0.9 0.8 0.3 0.3 0.3 0.3 0.3 0.3 Comparative Example 3 margin 1.0 0 0 0 0 0 0 0 Comparative Example 4 margin 1.0 0.2 0.15 0.15 0.15 0.15 0.15 0.15 Comparative Example 5 margin 1.0 0.2 0.15 0.15 0.15 0.15 0.15 0.15

[0094] According to the national standards of the People's Republic of China (GB / T32791-2016, GB / T228.1-2021, GB / T228.2-2015), the electrical conductivity, room temperature tensile properties and high temperature tensile properties of the embodiments and comparative examples were tested respectively. The performance parameters of the copper alloys of the above-mentioned embodiments and comparative examples are shown in Table 2 below. Compared with Comparative Example 1, Example 1 is not subjected to aging treatment, and the strengthening phase cannot be precipitated in the solid solution, resulting in a decrease in the mechanical properties and electrical conductivity of the alloy. Compared with Comparative Example 2, Example 2 adds an excessive amount of Ti element to Comparative Example 2. Excessive alloying elements easily cause alloy component segregation and coarsening of the intermediate phase, reducing the mechanical properties of the alloy. At the same time, excessive alloying elements increase the electron scattering of the matrix and thus reduce the electrical conductivity. Compared with Example 3 and Comparative Example 3, Ti, Zn, Sn, Si, Nb, Fe, and Co elements are not added in Comparative Example 3, and the mechanical properties of the comparative alloy are significantly reduced; adding an appropriate amount of alloying elements can promote the precipitation of Cr elements, inhibit the coarsening of Cr particles, and improve the precipitation strengthening effect. At the same time, the stable intermediate phase particles generated in the alloy improve the high-temperature mechanical properties and heat resistance of the alloy, so the performance of Example 3 is superior. Compared with Example 4, Example 3 has different aging treatment parameters and the performance is also very different. If the aging temperature is too low or the aging time is too short, it will lead to the occurrence of under-aging, thereby reducing the comprehensive performance of the alloy. Compared with Example 5, Example 3 does not undergo room temperature cold rolling treatment in Comparative Example 5, and the mechanical properties and electrical conductivity of the alloy are reduced. Cold rolling treatment can increase the dislocation density of the alloy, and defects such as dislocations in the alloy can promote the aging precipitation of Cr elements, etc. Therefore, cold rolling treatment combined with aging treatment improves the mechanical properties and electrical conductivity of the alloy.

[0095] Table 2 Performance data of copper alloys in various embodiments and comparative examples

[0096]

Claims

1. A high heat-resistant and high-conductivity copper alloy, characterized in that: In terms of mass percentage, the composition of the high heat-resistant and high-conductivity copper alloy includes: Cr: 0.1-1.5%, Ti: 0.01-0.5%, Zn: 0.01-0.5%, Sn: 0.01-0.5%, Si: 0.01-0.5%, Nb: 0.01-0.5%, Fe: 0.01-0.5%, Co: 0.01-0.2%, the balance Cu and inevitable impurities.

2. The high heat-resistant and high-conductivity copper alloy according to claim 1, characterized in that: In terms of mass percentage, the composition of the high heat-resistant and high-conductivity copper alloy includes: Cr: 0.8-1.0%, Ti: 0.2-0.3%, Zn: 0.1-0.2%, Sn: 0.1-0.2%, Si: 0.1-0.2%, Nb: 0.1-0.2%, Fe: 0.1-0.2%, Co: 0.1-0.15%, the balance is Cu and inevitable impurities.

3. The high heat-resistant and high-conductivity copper alloy according to claim 1 or 2, characterized in that: The high heat-resistant and high-conductivity copper alloy has an electrical conductivity of not less than 76.6% IACS, a tensile strength of not less than 517.3 MPa, and an elongation of not less than 12.6% at room temperature; at 300°C, its tensile strength is not less than 237.5 MPa, and its elongation is not less than 13.1%; at 600°C, its tensile strength is not less than 216.4 MPa, and its elongation is not less than 13.6%.

4. A method for preparing a high heat-resistant and high-conductivity copper alloy as claimed in any one of claims 1 to 3, characterized in that: The following steps are involved: (1) weighing a copper source, a chromium source, a titanium source, a zinc source, a tin source, a silicon source, a niobium source, an iron source, a cobalt source, etc. according to a mass ratio, and melting them in a heating furnace to obtain an alloy melt; (2) performing an upward continuous casting process on the alloy melt to obtain a rod material; (3) heating, keeping warm and continuously rolling the rod material to obtain a hot-rolled plate; (4) The hot-rolled sheet is subjected to cold rolling deformation, aging treatment, finish rolling treatment and stress relief annealing treatment to obtain a high heat-resistant and high-conductivity copper alloy.

5. The preparation method according to claim 4, characterized in that: In step (1), the copper source is pure copper, the chromium source is pure chromium or a copper-chromium alloy, the titanium source is pure titanium or a copper-titanium alloy, the zinc source is pure zinc or a copper-zinc alloy, the tin source is pure tin or a copper-tin alloy, the silicon source is pure silicon or a copper-silicon alloy, the niobium source is a copper-niobium alloy, the iron source is pure iron or a copper-iron alloy, and the cobalt source is pure cobalt or a copper-cobalt alloy.

6. The preparation method according to claim 4, characterized in that: In step (1), the specific preparation process of the alloy melt includes: first adding a copper source to a heating furnace, and raising the temperature in the heating furnace to 1350-1450°C to melt the copper source; after the copper source is fully melted, adding a chromium source, a titanium source, a tin source, a silicon source, a niobium source, an iron source, and a cobalt source to the heating furnace for melting, and heating the melt to increase the temperature to 1500-1600°C; after the raw materials are completely melted, reducing the melt temperature to 1300-1350°C and adding a zinc source for smelting to obtain an alloy melt.

7. The preparation method according to claim 4, characterized in that: In step (2), the temperature of the upward continuous casting is 1300-1350°C, and the speed of the upward continuous casting is 3-5 mm / s.

8. The preparation method according to claim 4, characterized in that: In step (3), the heating and heat preservation temperature is 900-950°C, and the heat preservation time is 5-10 minutes; the continuous hot rolling temperature is 900-950°C, and the total hot rolling deformation is 60-90%.

9. The preparation method according to claim 4, characterized in that: In step (4), the deformation amount of the cold rolling deformation is 40-80%, and the temperature of the cold rolling deformation is room temperature.

10. The preparation method according to claim 4, characterized in that: In step (4), the temperature of the aging treatment is 300-500°C, and the time of the aging treatment is 0.5-4h; the finishing rolling treatment adopts room temperature finishing rolling treatment, and the finishing rolling deformation is controlled to be 3-5%; the temperature of the stress relief annealing treatment is 200-300°C, and the treatment time is 0.5-2h.

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