A rare earth copper-tin-phosphorus alloy material and preparation method

Abstract

The present invention relates to a rare earth copper-tin-phosphorus alloy material and a preparation method thereof, wherein, in terms of weight percentage, the rare earth copper-tin-phosphorus alloy material comprises: Sn 7.5-8.0wt%, P 0.14-0.18wt%, rare earth element RE 0.05-0.15wt%, unavoidable impurity elements not exceeding 0.005wt%, and the remainder is copper. The preparation method thereof comprises: vacuum induction casting → homogenization → primary cold rolling → intermediate annealing → secondary cold rolling → low temperature annealing. The present invention obtains a Cu-Sn-P alloy material with high strength and high thermal stability by adding a trace amount of rare earth elements; the tensile strength of the alloy material is greater than 900MPa, the conductivity is greater than 12%IACS, and the elongation is greater than 20%; after the alloy material is subjected to high temperature heat treatment at 900°C, the tensile strength is greater than 300MPa, the average grain size is less than 20μm, and the conductivity is greater than 12%IACS. The present invention achieves comprehensive improvement of alloy strength, plasticity, conductivity, thermal stability and other properties with simple raw materials and processes, and the preparation process is easy to implement and can be industrialized for mass production.

Description

Technical Field

[0001] The invention relates to the technical field of nonferrous metal processing, in particular to a rare earth copper-tin-phosphorus alloy material and a preparation method thereof. Background Art

[0002] Tin-phosphor bronze alloy has high strength, elasticity and wear resistance, and is widely used in technical fields such as radiators, elastic components, precision instrument parts, and wear-resistant parts. However, the strength and electrical conductivity of the alloy are poorly matched, and it is difficult to further improve the strength of the alloy while ensuring electrical conductivity; in addition, the alloy has poor thermal stability, which limits its application in high-end fields.

[0003] At present, one prior art proposes a tin-phosphor bronze alloy and a preparation method thereof, but the alloy elements added are relatively large and the process is complicated; although the strength of the alloy is significantly improved, the elongation is greatly reduced, which is not conducive to processing and forming; and the high-temperature softening temperature is not significantly improved. Another prior art proposes a tin-phosphor bronze strip and a preparation method thereof, which improves the softening temperature and bending performance of the alloy by controlling the alloy elements and grain boundary ratios, but the strength is not significantly improved. At present, the prior art mainly adopts the composite addition of multiple trace elements to achieve the effect, or adjusts the deformation process route, but it will bring the defects of increased cost and complicated operation.

[0004] Therefore, it is of great significance and application value to develop a method for preparing high-performance copper-tin-phosphorus alloy with simple process and low cost. Summary of the invention

[0005] In view of this, the present invention provides a rare earth copper-tin-phosphorus alloy material and a preparation method, the main purpose of which is to use rare earth to improve the comprehensive properties of the copper-tin-phosphorus alloy, such as strength, plasticity, conductivity, and thermal stability.

[0006] In order to achieve the above object, the present invention mainly provides the following technical solutions:

[0007] On the one hand, an embodiment of the present invention provides a rare earth copper-tin-phosphorus alloy material, wherein, in terms of weight percentage, the rare earth copper-tin-phosphorus alloy material includes: Sn 7.5-8.0wt%, P 0.14-0.18wt%, rare earth element RE 0.05-0.15wt%, unavoidable impurity elements not exceeding 0.005wt%, and the balance is copper.

[0008] Preferably, the weight content ratio of the rare earth element RE to P is 0.5-1.5.

[0009] Preferably, the rare earth copper-tin-phosphorus alloy material has a micron-scale RECu4P3 phase and a nano-scale RE(Cu2P)2 phase. Preferably, the volume fraction of the micron-scale RECu4P3 phase is 20-30%, and the volume fraction of the nano-scale RE(Cu2P)2 phase is 15-20%. These precipitated phases are evenly distributed, mainly distributed in the crystal.

[0010] Preferably, the rare earth element RE in the rare earth copper-tin-phosphorus alloy material is one or two of La and Ce (herein, these two are light rare earth elements with abundant reserves, low cost, good chemical activity, and easy to combine with P element).

[0011] Preferably, after high-temperature heat treatment, the rare earth copper-tin-phosphorus alloy material has an average grain size of less than 25 μm; preferably, the high-temperature heat treatment is performed at a temperature of 900-980° C. and for a time of 15 min-3 h.

[0012] On the other hand, an embodiment of the present invention provides a method for preparing the rare earth copper-tin-phosphorus alloy material as described in any one of the above items, which comprises the following steps:

[0013] 1) melting and casting the raw materials to obtain alloy ingots;

[0014] 2) performing homogenization treatment on the alloy ingot to obtain a homogenized alloy;

[0015] 3) performing a primary cold rolling treatment, an intermediate annealing treatment, and a secondary cold rolling treatment on the homogenized alloy in sequence to obtain a cold rolled alloy;

[0016] 4) performing low temperature annealing on the alloy after the secondary cold rolling treatment to obtain a rare earth copper-tin-phosphorus alloy material; wherein the temperature of the low temperature annealing treatment is 200-230° C., and the holding time is 2-4 hours.

[0017] Preferably, in the step 1), the rare earth elements are added in the form of Cu-xRE intermediate alloy to prevent serious burning of pure rare earth elements, and the intermediate alloy is added more uniformly; wherein x is 15-25%, and the oxygen content of the Cu-xRE intermediate alloy is less than 5 ppm; preferably, the raw materials include: electrolytic copper plate, Sn, Cu-30P intermediate alloy (the mass fraction of P in the Cu-30P alloy is 30%), and Cu-xRE intermediate alloy.

[0018] Preferably, in step 1):

[0019] The smelting treatment temperature is 1200-1300°C; and / or

[0020] The timing of adding the Cu-xRE master alloy in the raw materials is: adding after the other raw materials are smelted; and / or

[0021] After the smelting treatment, the heat preservation is carried out after a set time, and the pouring treatment is carried out; preferably, the set time does not exceed 10 minutes; preferably, the pouring treatment temperature is 1150-1180°C; and / or

[0022] The electrolytic copper plate, Sn and Cu-30P intermediate alloy are loaded into a crucible; the metal Cu-xRE intermediate alloy is put into a secondary feeding tray, wrapped with copper foil to prevent it from being oxidized at high temperature, vacuumed, and the power is adjusted. After the heating is started for a set time, the electrolytic copper plate, Sn block and Cu-30P alloy are completely melted; the power is increased, and the temperature is adjusted to 1200-1300°C for refining to remove the gas therein. After 15-30 minutes, there is no boiling on the surface of the solution, and an inert gas is filled in, and the Cu-xRE alloy in the secondary feeding tray is added into the crucible, and the temperature is kept for a set time, and then the melting and pouring are carried out in a furnace to obtain an alloy ingot.

[0023] Preferably, in step 2), the temperature of the homogenization treatment is 600-700° C., and the time of the homogenization treatment is 5-10 h.

[0024] Preferably, in step 3):

[0025] In the step of the primary cold rolling treatment: the total deformation is controlled to be 80-90%; and / or

[0026] In the intermediate annealing step: the intermediate annealing temperature is 400-500°C, the intermediate annealing time is 2-4h, and the furnace is cooled; and / or

[0027] In the step of the secondary cold rolling treatment: the total deformation is controlled to be 60-80%; and / or

[0028] In the steps of the primary cold rolling treatment and the secondary cold rolling treatment: the deformation of a single pass is not more than 30%, and the deformation of each pass does not exceed the deformation of the previous pass; the total deformation of the secondary cold rolling treatment does not exceed 85% of the total deformation of the primary cold rolling treatment. Here, the purpose of such requirements is: the purpose of the pass arrangement is to make the deformation uniform, the structure uniform, and prevent warping deformation; the purpose of controlling the total deformation is to cooperate with the subsequent annealing process to achieve the best precipitation effect, and at the same time prevent rolling edge cracks caused by excessive deformation.

[0029] Compared with the prior art, the rare earth copper-tin-phosphorus alloy material and preparation method of the present invention have at least the following beneficial effects:

[0030] On the one hand, the rare earth copper-tin-phosphorus alloy material proposed in the embodiment of the present invention includes: Sn7.5-8.0wt%, P0.14-0.18wt%, rare earth element RE 0.05-0.15wt%, unavoidable impurity elements not greater than 0.005wt%, and the balance is copper. Here, the present invention adds trace rare earth elements to combine with Sn and P to form a new micron-scale (RECu4P3 phase) and nano-scale ternary phase (RE(Cu2P)2 phase), which is smaller in size and more evenly distributed, avoiding the weakening effect of the low melting point, coarse hard and brittle second phase (Cu3P) in the existing alloy on strength, plasticity and thermal stability. At the same time, due to the greater electronegativity difference between rare earth atoms and P atoms, the P element preferentially combines with the rare earth element, fixing the easily segregated P element and forming a stable and evenly distributed second phase (RECu4P3 phase, RE(Cu2P)2 phase), thus avoiding the problems of low strength and poor thermal stability caused by the segregation of the low-melting-point P-rich phase at the grain boundary in the original alloy.

[0031] On the other hand, the preparation method of the rare earth copper-tin-phosphorus alloy material proposed in the embodiment of the present invention, based on the above-mentioned component formula, promotes the formation of micron-scale (RECu4P3 phase) and nanoscale ternary phase (RE(Cu2P)2 phase) with a simple process, so that the finally prepared rare earth copper-tin-phosphorus alloy material has excellent comprehensive properties such as strength, plasticity, conductivity, and thermal stability.

[0032] Furthermore, in order to ensure the dispersed precipitation of the above-mentioned nanoscale RE (Cu2P)2 strengthening phase, the following coordinated conditions need to be met: (1) the ratio of rare earth element content to P content is controlled to be 0.5-1.5 to avoid the adverse effects of excessive rare earth or P elements; (2) the alloy should be subjected to low temperature annealing (200-230°C, 2-4h when keeping warm) after deformation to ensure the precipitation of the nanophase.

[0033] In summary, the present invention obtains a Cu-Sn-P alloy material with high strength and high thermal stability by adding a trace amount of rare earth elements; the tensile strength of the alloy material is greater than 900MPa, the conductivity is greater than 12%IACS, and the elongation is greater than 20%; after the alloy material is subjected to high-temperature heat treatment at 900°C, the tensile strength is greater than 300MPa, the average grain size is less than 20μm, and the conductivity is greater than 12%IACS. The present invention achieves a comprehensive improvement in the strength, plasticity, conductivity, thermal stability and other properties of the alloy with simple raw materials and processes, and the preparation process is easy to implement and can be industrialized for mass production.

[0034] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the following is a detailed description of the preferred embodiments of the present invention in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 is a microstructure diagram of the rare earth copper-tin-phosphorus alloy material prepared in Example 1;

[0036] Figure 2 This is a microstructure diagram of the rare earth copper-tin-phosphorus alloy material prepared in Comparative Example 1. DETAILED DESCRIPTION

[0037] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the specific implementation methods, structures, features and effects of the present invention application are described in detail below in conjunction with the accompanying drawings and preferred embodiments. In the following description, different "one embodiment" or "embodiment" does not necessarily refer to the same embodiment. In addition, specific features, structures, or characteristics in one or more embodiments may be combined in any suitable form.

[0038] The present invention proposes to prepare a copper-tin-phosphorus alloy by adding trace rare earth elements to improve comprehensive properties such as strength, plasticity, conductivity, and thermal stability. The main scheme of the present invention is as follows:

[0039] On the one hand, the present invention provides a rare earth copper-tin-phosphorus alloy material, wherein, in terms of weight percentage, the rare earth copper-tin-phosphorus alloy material comprises: Sn 7.5-8.0wt%, P 0.14-0.18wt%, rare earth element RE 0.05-0.15wt%, unavoidable impurity elements not exceeding 0.005wt%, and the balance is copper. Preferably, the weight content ratio of the rare earth element RE to P is 0.5-1.5. The rare earth element is one or both of La and Ce.

[0040] On the other hand, the present invention provides a method for preparing the above rare earth copper-tin-phosphorus alloy material, which mainly comprises the following steps:

[0041] 1) The raw materials are smelted and cast to obtain alloy ingots.

[0042] The melting temperature is 1200-1300°C and the pouring temperature is controlled at 1150-1180°C.

[0043] After smelting, the alloy is poured into a mold after being kept warm for a period of time, and the holding time does not exceed 10 minutes.

[0044] Preferably, the electrolytic copper plate, Sn, and Cu-30P intermediate alloy are loaded into a crucible; the metal Cu-xRE intermediate alloy is placed in a secondary feeding tray, wrapped with copper foil to prevent it from being oxidized at high temperature, evacuated, the power is adjusted, and heating is started after a set time (the heating temperature is 1170-1200°C), and the electrolytic copper plate, Sn block, and Cu-30P alloy are completely melted; the power is increased, and the temperature is adjusted to 1200-1300°C for refining to remove the gas therein. After 30 minutes, there is no boiling on the surface of the solution, and an inert gas is filled in, and the Cu-xRE alloy in the secondary feeding tray is added to the crucible, kept warm for a set time, and then melted in a furnace, poured, and an alloy ingot is obtained.

[0045] 2) Performing homogenization treatment on the alloy ingot to obtain a homogenized alloy.

[0046] The homogenization treatment temperature is 600-700°C and the insulation time is 5-10h.

[0047] 3) The homogenized alloy is subjected to a primary cold rolling treatment, an intermediate annealing treatment, and a secondary cold rolling treatment in sequence to obtain a cold rolled alloy.

[0048] The total deformation of one cold rolling process is controlled at 80-90%.

[0049] The annealing temperature of the intermediate annealing treatment is 400-500°C, the annealing time is 2-4h, and the furnace is cooled.

[0050] The total deformation of the secondary cold rolling process is controlled at 60-80%.

[0051] In the primary cold rolling process and the secondary cold rolling process, the deformation amount of a single pass is not greater than 30%, and the deformation amount of each pass does not exceed the deformation amount of the previous pass; the total deformation amount of the secondary cold rolling process does not exceed 85% of the total deformation amount of the primary cold rolling process.

[0052] 4) performing low temperature annealing on the alloy after the secondary cold rolling treatment to obtain a rare earth copper-tin-phosphorus alloy material; wherein the temperature of the low temperature annealing treatment is 200-230° C., and the holding time is 2-4 hours.

[0053] Regarding the above technical solution of the present invention, the design concept of the present invention is as follows: by adding a trace amount of rare earth elements, it is combined with Sn and P to form a new micron-level (RECu4P3 phase) phase and a nano-level ternary phase (RE(Cu2P)2 phase), which is smaller in size and more evenly distributed, avoiding the weakening effect of the low-melting-point, coarse, hard and brittle second phase (Cu3P) in the original alloy on strength, plasticity and thermal stability. At the same time, due to the greater difference in electronegativity between rare earth atoms and P atoms, the P element preferentially combines with the rare earth element, fixes the P element that is easy to segregate and forms a stable and evenly distributed second phase (RECu4P3 phase, RE(Cu2P)2 phase), avoiding the problems of low strength and poor thermal stability caused by the segregation of the low-melting-point P-rich phase at the grain boundary in the original alloy;

[0054] Furthermore, in order to ensure the dispersed precipitation of the above-mentioned nanoscale RE (Cu2P)2 strengthening phase, the following coordinated conditions need to be met: (1) the ratio of rare earth element content to P content is controlled to be 0.5-1.5 to avoid the adverse effects of excessive rare earth or P elements; (2) the alloy should be subjected to low temperature annealing (200-230°C, 2-4h when keeping warm) after deformation to ensure the precipitation of the nanophase.

[0055] In addition, the addition of trace rare earths can purify the matrix and have a good effect on improving conductivity. Therefore, adding reasonable rare earth elements can significantly improve and enhance the comprehensive properties of the alloy.

[0056] In summary, the rare earth copper-tin-phosphorus alloy material described in the present invention has a simple composition and a simple preparation process; by adding trace rare earth elements and adjusting the element ratio, the comprehensive improvement of the alloy's strength, plasticity, conductivity, thermal stability and other properties can be achieved, and the preparation method is easy to implement and can be industrialized for mass production.

[0057] The present invention is further described below by specific embodiments:

[0058] Example 1

[0059] This embodiment prepares a rare earth copper-tin-phosphorus alloy material; wherein, in terms of weight percentage, the rare earth copper-tin-phosphorus alloy material contains: Sn 7.6wt%, P 0.16wt%, rare earth (La) 0.15wt%, and the sum of unavoidable impurity elements is not more than 0.005wt%, and the balance is copper.

[0060] The specific preparation process is as follows:

[0061] 1) Vacuum induction melting: After weighing the raw materials according to the above weight percentage, the electrolytic copper plate, pure Sn and Cu-30P master alloy are loaded into a crucible; the metal Cu-20La master alloy (the mass fraction of La is 20%) is placed in a secondary feeding tray, wrapped with copper foil to prevent it from being oxidized at high temperature, evacuated to about 10Pa, the power is adjusted, and heating is started. At this time, the temperature is about 1200°C. After heating for 20 minutes, the Cu block, Sn block and Cu-30P alloy are completely melted; the power is increased, and the temperature is adjusted to 1200-1300°C for refining, mainly to remove the gas therein. After about 30 minutes, there is no boiling on the surface of the solution, and argon gas is filled, and the Cu-20La alloy in the secondary tray is added to the crucible, kept warm for 10 minutes, and then melted in the furnace and poured; wherein the pouring temperature is about 1170°C, and the alloy ingot is obtained after cooling to room temperature.

[0062] 2) performing homogenization treatment on the alloy ingot to obtain a homogenized alloy; wherein the homogenization treatment temperature is 680±10° C. and the homogenization treatment time is 5 h.

[0063] 3) The homogenized alloy is subjected to a first cold rolling treatment, an intermediate annealing treatment, and a second cold rolling treatment in sequence to obtain a cold rolled alloy. The deformation amount of the first cold rolling treatment is 80%, and the deformation amount of the second cold rolling treatment is 60%; the temperature of the intermediate annealing treatment is 480±10°C, the time of the intermediate annealing treatment is 2h, and the alloy is cooled in the furnace.

[0064] 4) performing low-temperature annealing on the alloy after the secondary cold rolling treatment to obtain a rare earth copper-tin-phosphorus alloy material; wherein the temperature of the low-temperature annealing treatment is 210° C. and the holding time is 2 h.

[0065] The microstructure of the rare earth copper-tin-phosphorus alloy material prepared in this example is shown in Figure 1 As shown. Among them, Figure 1 The right image is an enlarged part of the red frame in the left image. It can be seen that the rare earth copper-tin-phosphorus alloy material contains a large amount of uniformly distributed second phases (the volume fraction of the micron-level LaCu4P3 phase is 25%, and the volume fraction of the nano-level La(Cu2P)2 phase is 20%). These second phases avoid the weakening effect of the low melting point, coarse and brittle second phase (Cu3P) in the existing copper-tin-phosphorus alloy on strength, plasticity and thermal stability, and avoid the problems of low strength and poor thermal stability caused by the low melting point P-rich phase in the original alloy segregating at the grain boundary.

[0066] Example 2

[0067] This embodiment prepares a rare earth copper-tin-phosphorus alloy material; wherein, in terms of weight percentage, the rare earth copper-tin-phosphorus alloy material contains: Sn 7.5wt%, P 0.14wt%, rare earth (La) 0.14wt%, and the sum of unavoidable impurity elements not exceeding 0.005wt%, and the balance is copper.

[0068] The specific preparation process is as follows:

[0069] 1) Vacuum induction melting: After weighing the raw materials according to the above weight percentage, the electrolytic copper plate, pure Sn and Cu-30P master alloy are loaded into a crucible; the metal Cu-20La master alloy (the mass fraction of La is 20%) is placed in a secondary feeding tray, wrapped with copper foil to prevent it from being oxidized at high temperature, evacuated to about 10Pa, the power is adjusted, and heating is started. At this time, the temperature is about 1200°C. After heating for 20 minutes, the Cu block, Sn block and Cu-30P alloy are completely melted; the power is increased, and the temperature is adjusted to 1200-1300°C for refining, mainly to remove the gas therein. After about 30 minutes, there is no boiling on the surface of the solution, and argon gas is filled, and the Cu-20La alloy in the secondary tray is added to the crucible, kept warm for 10 minutes, and then melted in the furnace and poured; wherein the pouring temperature is about 1170°C, and the alloy ingot is obtained after cooling to room temperature.

[0070] 2) performing homogenization treatment on the alloy ingot to obtain a homogenized alloy; wherein the homogenization treatment temperature is 680±10° C. and the homogenization treatment time is 5 h.

[0071] 3) The homogenized alloy is subjected to a first cold rolling treatment, an intermediate annealing treatment, and a second cold rolling treatment in sequence to obtain a cold rolled alloy. The deformation amount of the first cold rolling treatment is 80%, and the deformation amount of the second cold rolling treatment is 60%; the temperature of the intermediate annealing treatment is 480±10°C, the time of the intermediate annealing treatment is 2h, and the alloy is cooled in the furnace.

[0072] 4) performing low-temperature annealing on the alloy after the secondary cold rolling treatment to obtain a rare earth copper-tin-phosphorus alloy material; wherein the temperature of the low-temperature annealing treatment is 210° C. and the holding time is 2 h.

[0073] The microstructure of the rare earth copper-tin-phosphorus alloy material prepared in this embodiment is the same as that in Embodiment 1, and there is a uniformly distributed second phase (micrometer-scale LaCu4P3 phase and nanometer-scale La(Cu2P)2 phase), but the overall content is reduced compared with that in Embodiment 1, which is due to the reduction in the content of added elements.

[0074] Example 3

[0075] This embodiment prepares a rare earth copper-tin-phosphorus alloy material; wherein, in terms of weight percentage, the rare earth copper-tin-phosphorus alloy material contains: Sn 7.5wt%, P 0.18wt%, rare earth (La) 0.05wt%, and the sum of unavoidable impurity elements not exceeding 0.005wt%, and the balance is copper.

[0076] The specific preparation process is as follows:

[0077] 1) Vacuum induction melting: After weighing the raw materials according to the above weight percentage, the electrolytic copper plate, pure Sn and Cu-30P master alloy are loaded into a crucible; the metal Cu-20La master alloy (the mass fraction of La is 20%) is placed in a secondary feeding tray, wrapped with copper foil to prevent it from being oxidized at high temperature, evacuated to about 10Pa, the power is adjusted, and heating is started. At this time, the temperature is about 1200°C. After heating for 20 minutes, the Cu block, Sn block and Cu-30P alloy are completely melted; the power is increased, and the temperature is adjusted to 1200-1300°C for refining, mainly to remove the gas therein. After about 30 minutes, there is no boiling on the surface of the solution, and argon gas is filled, and the Cu-20La alloy in the secondary tray is added to the crucible, kept warm for 10 minutes, and then melted in the furnace and poured; wherein the pouring temperature is about 1170°C, and the alloy ingot is obtained after cooling to room temperature.

[0078] 2) performing homogenization treatment on the alloy ingot to obtain a homogenized alloy; wherein the homogenization treatment temperature is 680±10° C. and the homogenization treatment time is 5 h.

[0079] 3) The homogenized alloy is subjected to a first cold rolling treatment, an intermediate annealing treatment, and a second cold rolling treatment in sequence to obtain a cold rolled alloy. The deformation amount of the first cold rolling treatment is 80%, and the deformation amount of the second cold rolling treatment is 60%; the temperature of the intermediate annealing treatment is 480±10°C, the time of the intermediate annealing treatment is 2h, and the alloy is cooled in the furnace.

[0080] 4) performing low-temperature annealing on the alloy after the secondary cold rolling treatment to obtain a rare earth copper-tin-phosphorus alloy material; wherein the temperature of the low-temperature annealing treatment is 210° C. and the holding time is 2 h.

[0081] Compared with Example 1, the microstructure of the rare earth copper-tin-phosphorus alloy material prepared in this embodiment has only a small amount of micron-sized LaCu4P3 phase and nano-sized La(Cu2P)2 phase), and there are more Cu3P low-melting point brittle phases distributed at the grain boundaries, resulting in the overall performance of the alloy being deteriorated. This is because the rare earth La element is added less, resulting in a large amount of P element remaining and combining with the Cu element (that is, the weight content ratio of the rare earth element RE to P is not in the range of 0.5-1.5). Although there are also a small amount of micron-sized LaCu4P3 phase and nano-sized La(Cu2P)2 phase, there will be a Cu3P low-melting point brittle phase. However, there is basically no Cu3P low-melting point brittle phase in Example 1-2).

[0082] Comparative Example 1

[0083] Comparative Example 1: A copper-tin-phosphorus alloy material is prepared; wherein, in terms of weight percentage, the copper-tin-phosphorus alloy material contains: Sn 7.6wt%, P 0.16wt%, and the sum of unavoidable impurity elements is not more than 0.005wt%, and the balance is copper.

[0084] 1) Vacuum induction melting: After weighing the raw materials according to the above weight percentage, the electrolytic copper plate, pure Sn, and Cu-30P master alloy are loaded into the crucible, and the vacuum is evacuated to about 10Pa. The power is adjusted and heating is started. At this time, the temperature is about 1200°C. After 20 minutes, the Cu block, Sn block, and Cu-30P alloy are completely melted; the power is increased and the temperature is adjusted to 1200-1300°C for refining, mainly to remove the gas therein. After about 30 minutes, there is no boiling on the surface of the solution, and argon gas is filled, and then the furnace is melted and cast. The casting temperature is about 1170°C, and the alloy is cooled to room temperature to obtain the alloy ingot.

[0085] 2) performing homogenization treatment on the alloy ingot to obtain a homogenized alloy; wherein the homogenization treatment temperature is 680±10° C. and the homogenization treatment time is 5 h.

[0086] 3) The homogenized alloy is subjected to a first cold rolling treatment, an intermediate annealing treatment, and a second cold rolling treatment in sequence to obtain a cold rolled alloy. The deformation amount of the first cold rolling treatment is 80%, and the deformation amount of the second cold rolling treatment is 60%; the temperature of the intermediate annealing treatment is 480±10°C, the time of the intermediate annealing treatment is 2h, and the alloy is cooled in the furnace.

[0087] 4) performing low-temperature annealing on the alloy after the secondary cold rolling treatment to obtain a copper-tin-phosphorus alloy material; wherein the temperature of the low-temperature annealing treatment is 210° C. and the holding time is 2 hours.

[0088] The microstructure of the copper-tin-phosphorus alloy material prepared in Comparative Example 1 is shown in Figure 2 As shown. Among them, Figure 2The picture on the right is an enlarged part of the red frame in the picture on the left. It can be seen that coarse Cu3P phases are distributed in the alloy. These low-melting-point brittle phases have a serious weakening effect on the strength and thermal stability of the alloy.

[0089] In addition, the performance of the alloy materials prepared in Example 1 and Comparative Example 1 was tested, and the test data are shown in Table 1.

[0090] Table 1 shows the comprehensive properties of the alloy materials prepared in Example 1 and Comparative Example 1

[0091]

[0092] It can be seen from Table 1 that the comprehensive performance of the rare earth copper-tin-phosphorus alloy material prepared in Example 1 of the present invention is far superior to that in Comparative Example 1.

[0093] Comparative Example 2

[0094] Comparative Example 2: A rare earth copper-tin-phosphorus alloy material is prepared; wherein, in terms of weight percentage, the rare earth copper-tin-phosphorus alloy material contains: Sn 7.6wt%, P 0.16wt%, rare earth (La) 0.15wt%, and the sum of unavoidable impurity elements not exceeding 0.005wt%, and the balance is copper.

[0095] The specific preparation process is as follows:

[0096] 1) Vacuum induction melting: After weighing the raw materials according to the above weight percentage, the electrolytic copper plate, pure Sn and Cu-30P master alloy are loaded into a crucible; the metal Cu-20La master alloy (the mass fraction of La is 20%) is placed in a secondary feeding tray, wrapped with copper foil to prevent it from being oxidized at high temperature, evacuated to about 10Pa, the power is adjusted, and heating is started. At this time, the temperature is about 1200°C. After heating for 20 minutes, the Cu block, Sn block and Cu-30P alloy are completely melted; the power is increased, and the temperature is adjusted to 1200-1300°C for refining, mainly to remove the gas therein. After about 30 minutes, there is no boiling on the surface of the solution, and argon gas is filled, and the Cu-20La alloy in the secondary tray is added to the crucible, kept warm for 10 minutes, and then melted in the furnace and poured; wherein the pouring temperature is about 1170°C, and the alloy ingot is obtained after cooling to room temperature.

[0097] 2) performing homogenization treatment on the alloy ingot to obtain a homogenized alloy; wherein the homogenization treatment temperature is 680±10° C. and the homogenization treatment time is 5 h.

[0098] 3) The homogenized alloy is subjected to a first cold rolling treatment, an intermediate annealing treatment, and a second cold rolling treatment in sequence to obtain a cold rolled alloy. The deformation amount of the first cold rolling treatment is 80%, and the deformation amount of the second cold rolling treatment is 60%; the temperature of the intermediate annealing treatment is 480±10°C, the time of the intermediate annealing treatment is 2h, and the alloy is cooled in the furnace.

[0099] The rare earth copper-tin-phosphorus alloy material prepared in Comparative Example 2 has a relatively low content of precipitated phase in its microstructure, and most of the added elements are still present in the Cu matrix in the form of solid solution, but not fully precipitated, which results in poor strength and conductivity of the alloy. This is mainly because the alloy material has not been subjected to low-temperature annealing treatment, and the alloy elements have not been effectively precipitated to form nano-scale and submicron-scale second phases.

[0100] In summary, the rare earth copper-tin-phosphorus alloy material described in the present invention has a simple composition and a simple preparation process; by adding trace rare earth elements and adjusting the element ratio, the comprehensive improvement of the alloy's strength, plasticity, conductivity, thermal stability and other properties can be achieved, and the preparation method is easy to implement and can be industrialized for mass production.

[0101] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any simple modification, equivalent change and modification made to the above embodiment according to the technical essence of the present invention still falls within the scope of the technical solution of the present invention.

Claims

1. A rare earth copper-tin-phosphorus alloy material, characterized in that: The chemical composition of the rare earth copper-tin-phosphorus alloy material is as follows in terms of weight percentage: Sn 7.5-8.0wt%, P 0.14-0.18wt%, rare earth element RE 0.05-0.15wt%, unavoidable impurity elements not exceeding 0.005wt%, and the balance is copper; wherein the weight ratio of rare earth element RE to P is 0.5-1.5; The rare earth copper-tin-phosphorus alloy material has a micron-scale RECu4P3 phase and a nano-scale RE(Cu2P)2 phase; the volume fraction of the micron-scale RECu4P3 phase is 20-30%, and the volume fraction of the nano-scale RE(Cu2P)2 phase is 15-20%; The method for preparing the rare earth copper-tin-phosphorus alloy material comprises the following steps: 1) The raw materials are subjected to smelting and casting treatment to obtain alloy ingots; wherein the rare earth element is added in the form of Cu-xRE master alloy; wherein x is 15-25%, and the oxygen content of the Cu-xRE master alloy is less than 5 PPm; 2) performing homogenization treatment on the alloy ingot to obtain a homogenized alloy; 3) performing a primary cold rolling treatment, an intermediate annealing treatment, and a secondary cold rolling treatment on the homogenized alloy in sequence to obtain a cold-rolled alloy; wherein the intermediate annealing treatment temperature is 400-500° C., the intermediate annealing treatment time is 2-4 hours, and the alloy is cooled in the furnace; 4) performing low temperature annealing on the alloy after the secondary cold rolling treatment to obtain a rare earth copper-tin-phosphorus alloy material; wherein the temperature of the low temperature annealing treatment is 200-230° C. and the holding time is 2-4 hours.

2. The rare earth copper-tin-phosphorus alloy material according to claim 1, characterized in that: The rare earth element RE in the rare earth copper-tin-phosphorus alloy material is one or two of La and Ce.

3. The rare earth copper-tin-phosphorus alloy material according to claim 1, characterized in that: After high-temperature heat treatment, the rare earth copper-tin-phosphorus alloy material has an average grain size of less than 25 μm; Wherein, the temperature of the high temperature heat treatment is 900-980°C and the time is 15min-3h.

4. The rare earth copper-tin-phosphorus alloy material according to claim 1, characterized in that: In step 1): The raw materials include: electrolytic copper plate, Sn, Cu-30P master alloy and Cu-xRE master alloy.

5. The rare earth copper-tin-phosphorus alloy material according to any one of claims 1 to 4, characterized in that: In step 1): The temperature of the smelting treatment is 1200-1300°C; and / or The timing of adding the Cu-xRE master alloy in the raw materials is: adding after the other raw materials are smelted; and / or After the smelting treatment, the casting treatment is carried out after the heat preservation setting time; wherein the setting time does not exceed 10 minutes; wherein the casting treatment temperature is 1150-1180°C; and / or The electrolytic copper plate, Sn and Cu-30P intermediate alloy are loaded into a crucible; the metal Cu-xRE intermediate alloy is put into a secondary feeding tray, wrapped with copper foil to prevent it from being oxidized at high temperature, vacuumed, and the power is adjusted. After the heating is started for a set time, the electrolytic copper plate, Sn block and Cu-30P alloy are completely melted; the power is increased, and the temperature is adjusted to 1200-1300°C for refining to remove the gas therein. After 15-30 minutes, there is no boiling on the surface of the solution, and an inert gas is filled in, and the Cu-xRE alloy in the secondary feeding tray is added into the crucible, and the temperature is kept for a set time, and then the melting and pouring are carried out in a furnace to obtain an alloy ingot.

6. The rare earth copper-tin-phosphorus alloy material according to claim 1, characterized in that: In step 2): The temperature of the homogenization treatment is 600-700° C., and the time of the homogenization treatment is 5-10 hours.

7. The rare earth copper-tin-phosphorus alloy material according to any one of claim 1, characterized in that: In step 3): In the step of the primary cold rolling treatment: the total deformation is controlled to be 80-90%; and / or In the step of the secondary cold rolling treatment: the total deformation is controlled to be 60-80%; and / or In the steps of the primary cold rolling treatment and the secondary cold rolling treatment: the deformation amount of a single pass is not greater than 30%, and the deformation amount of each pass does not exceed the deformation amount of the previous pass; and / or The total deformation amount of the secondary cold rolling process does not exceed 85% of the total deformation amount of the primary cold rolling process.

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