Rare earth copper-tin alloy and preparation method and application thereof

Abstract

The invention relates to the technical field of alloy materials, and discloses a copper-tin alloy and a preparation method and application thereof, and the copper-tin alloy is composed of copper, tin and rare earth elements. The rare earth element comprises scandium and / or erbium, the mass percentage content of the tin element is 0.1%-0.5%, the mass percentage content of the rare earth element is 0.1%-0.4%, and the balance is the copper element. By adding scandium and / or erbium, grains can be obviously refined, and the strength of the alloy is improved; the Sn element can be easily separated out from a copper matrix, so that the number of solute atoms in the matrix is reduced, the content of the Sn element is reduced, and the conductivity of the alloy is improved; and the formed RE-phase-containing copper-tin alloy has a high melting point, and the high-temperature softening resistance of the alloy can be remarkably improved. According to the preparation method of the rare earth copper-tin alloy, through multiple times of drawing and multiple times of aging treatment, Sn segregation is restrained, precipitation of the Sn element is promoted, meanwhile, solute atoms can be further precipitated, and therefore the electric conductivity of the alloy is improved.

Description

Technical Field

[0001] The present application relates to the technical field of alloy materials, and in particular to a rare earth copper-tin alloy and a preparation method and use thereof. Background Art

[0002] Cu-Sn alloy (copper-tin alloy) material is one of the most important materials in electrical and electronic equipment and transportation. It maintains the superior electrical conductivity of copper. Compared with copper, Cu-Sn alloy material can effectively reduce resistance and improve current transmission efficiency. In addition, copper-tin alloy wire also has excellent wear resistance and high strength. However, with the advancement and development of science and technology, higher requirements are put forward for the conductivity and strength of Cu-Sn alloy materials, and more attention is also paid to anti-softening performance.

[0003] The strength of traditional copper-tin alloy is relatively moderate. When the temperature is higher than 300°C, the strength drops significantly. It is not suitable for the softening resistance requirements at higher temperatures, which limits the widespread application of Cu-Sn alloy materials. Summary of the invention

[0004] In view of this, the present application provides a rare earth copper-tin alloy and a preparation method and use thereof, so as to solve the problem that the existing copper-tin alloy has insufficient strength and poor softening resistance.

[0005] In a first aspect, the present application provides a rare earth copper-tin alloy.

[0006] The rare earth copper-tin alloy is composed of copper, tin and rare earth elements; the rare earth elements include Sc (scandium) and / or Er (erbium);

[0007] Based on the total mass of the rare earth copper-tin alloy, the mass percentage of tin element is 0.1% to 0.5%, the mass percentage of rare earth element is 0.1% to 0.4%, and the balance is copper element.

[0008] In an optional embodiment, based on the total mass of the rare earth copper-tin alloy, the mass percentage of tin element is 0.2% to 0.4%, the mass percentage of rare earth element is 0.2% to 0.3%, and the balance is copper element.

[0009] In an optional embodiment, the rare earth elements include Sc and Er, and in the rare earth copper-tin alloy, the mass ratio of Sc to Er is (1.5-2.5): (1-3).

[0010] In a second aspect, the present application also provides a method for preparing the rare earth copper-tin alloy.

[0011] The preparation method of the rare earth copper-tin alloy comprises:

[0012] The copper, tin and rare earth elements are smelted and pulled under the protection of nitrogen or inert atmosphere to obtain a casting billet;

[0013] The ingot is first subjected to a solution treatment, and then subjected to at least two cold drawing treatments and at least two aging treatments to obtain a rare earth-reinforced copper-tin alloy material;

[0014] Preferably, the at least two cold drawing treatments and the at least two aging treatments include a first cold drawing treatment, a first aging treatment, a second cold drawing treatment, a second aging treatment and a third cold drawing treatment performed sequentially.

[0015] In an optional embodiment, the purity of copper, tin, scandium or erbium is 99.99% or more;

[0016] and / or, the smelting temperature is 1300-1350° C., and the smelting time is 0.5-1 h;

[0017] And / or, the pulling temperature is 1280-1320°C.

[0018] In an optional embodiment, vacuum evacuation is performed before smelting to a vacuum degree not higher than 10 -1 Pa;

[0019] and / or, after vacuum evacuation, the furnace is washed with inert gas at least twice and then smelting is carried out under the protection of an inert atmosphere;

[0020] Preferably, the inert gas includes nitrogen and / or argon, and the purity of the inert gas is >99.99%.

[0021] In an optional embodiment, the solution treatment temperature is 900-1000° C., and the time is 0.5-1.5 h.

[0022] In an optional embodiment, the cold drawing treatment and the aging treatment satisfy at least one of the following conditions A to E:

[0023] A: The first cold drawing process causes the diameter deformation rate of the material to be 70% to 90% (the average diameter is reduced);

[0024] B: The temperature of the first aging treatment is 350-400°C and the time is 0.5-1.5h;

[0025] C: The second cold drawing process causes the diameter deformation rate of the material to be (the average diameter is reduced) 50% to 70%;

[0026] D: The temperature of the second aging treatment is 350-400°C and the time is 0.5-1.5h;

[0027] E: The third cold drawing process causes the diameter deformation rate of the material to be 60% to 80% (the average diameter is reduced).

[0028] In an optional embodiment, the cold drawing treatment and the aging treatment specifically include: the first cold drawing treatment pulls the average diameter of the material from 18 mm to 3 mm; the second cold drawing treatment pulls the average diameter of the material from 3 mm to 1 mm; the third cold drawing treatment pulls the average diameter of the material from 1 mm to 0.3 mm.

[0029] In a third aspect, the present application also provides a use of the rare earth copper-tin alloy or the rare earth copper-tin alloy obtained by the preparation method in cables, transformers, motors or electronic equipment; the cables include high-speed railway contact wires.

[0030] Compared with the prior art, the beneficial effects of this application are:

[0031] The rare earth copper-tin alloy of the present application is composed of copper, tin and rare earth elements; the rare earth elements include Sc and / or Er; based on the total mass of the rare earth copper-tin alloy, the mass percentage of tin element is 0.1% to 0.5%, the mass percentage of rare earth element is 0.1% to 0.4%, and the balance is copper element. The addition of a small amount of Sc and / or Er can significantly refine the grains, achieve fine grain strengthening, and improve the strength of the alloy, so that the tensile strength of the Cu-Sn alloy reaches 750MPa to 820MPa; secondly, the addition of a small amount of Sc and / or Er helps the Sn element to precipitate from the copper matrix, thereby reducing the number of solute atoms in the matrix, reducing the content of the Sn element, and improving the electrical conductivity of the alloy, with the electrical conductivity reaching 75% IACS to 82% IACS. Thirdly, the rare earth copper-tin alloy formed by copper, tin and rare earth elements at a specific mass content has a high melting point, which can significantly increase the high-temperature softening resistance of the alloy, and its softening temperature can reach 550°C to 620°C.

[0032] The preparation method of the rare earth copper-tin alloy of the present application includes: melting copper, tin and rare earth elements under atmosphere protection, pulling, and obtaining a cast billet; first subjecting the cast billet to solid solution treatment, and then subjecting the cast billet to at least two cold drawing treatments and at least two aging treatments, to obtain a rare earth-enhanced copper-tin alloy material; melting and pulling under atmosphere protection reduce the burning loss of Sn and the oxygen content, and realize the continuous preparation of the cast billet. Multiple drawing and multiple aging treatments inhibit Sn segregation and promote the precipitation of Sn elements. More than two aging treatments can produce a large number of deformation twins, and at the same time can further precipitate solute atoms, thereby improving the conductivity of the alloy. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the specific implementation methods of the present application or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0034] Figure 1 This is a SEM image of the ingot obtained in Example 5 of the present application, magnified 1000 times;

[0035] Figure 2 This is a SEM image of the ingot obtained in Example 5 of the present application, magnified 300 times. DETAILED DESCRIPTION

[0036] The following examples are provided for a better understanding of the present application, but are not limited to the best implementation mode described, and do not limit the content and protection scope of the present application. Any product identical or similar to the present application obtained by anyone under the inspiration of the present application or by combining the features of the present application with other prior arts shall fall within the protection scope of the present application.

[0037] Unless otherwise specified or incompatible herewith, the terms and phrases used herein shall have the following meanings:

[0038] In this application, the selection scope of "and / or" includes any one of two or more related listed items, and also includes any and all combinations of related listed items, and the said any and all combinations include any combination of two related listed items, any more related listed items, or all related listed items. For example, "A and / or B" includes three parallel solutions of A, B and A+B.

[0039] In this application, "optionally" refers to optional, that is, it refers to any one of the two parallel solutions of "yes" or "no". If there are multiple "options" in a technical solution, unless otherwise specified and there is no contradiction or mutual restriction, each "option" is independent.

[0040] In the present application, the technical features described in an open manner include closed technical solutions composed of the listed features, and also include open technical solutions containing the listed features.

[0041] In the present application, the percentage content, unless otherwise specified, refers to mass percentage for solid-liquid mixing and solid-solid mixing, and refers to volume percentage for liquid-liquid mixing.

[0042] In this application, when it comes to percentage concentration, unless otherwise specified, it refers to the final concentration. The final concentration refers to the proportion of the added component in the system after the addition of the component.

[0043] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0044] Compared with copper alone, the copper-tin alloy composed of the two elements copper and tin has high mechanical strength and hardness, good casting and processing properties, corrosion resistance, good load-bearing performance, appropriate conductivity and easy welding.

[0045] With the development of the electronic and electrical industry, higher strength alloys are needed. The strength of traditional copper-tin alloys is generally 500-600 MPa. Moreover, the strength drops significantly when the temperature is higher than 300°C, which limits the widespread application of Cu-Sn alloy materials. The development of high-strength, high-conductivity and high-temperature softening-resistant Cu-Sn alloy materials has become a research hotspot at home and abroad.

[0046] In order to solve the problems existing in the above-mentioned related technologies, according to the first aspect of the present application, the present application provides a rare earth copper-tin alloy.

[0047] In some embodiments, the rare earth copper-tin alloy is composed of copper, tin and rare earth elements; the rare earth elements include Sc (scandium) and / or Er (erbium);

[0048] Based on the total mass of the rare earth copper-tin alloy, the mass percentage of tin element is 0.1% to 0.5%, the mass percentage of rare earth element is 0.1% to 0.4%, and the balance is copper element.

[0049] Scandium (element symbol is Sc) is a soft, silvery-white transition metal with a melting point of 1814K (1541℃) and a boiling point of 3103K (2830℃). It is often mixed with gadolinium, erbium, etc. Its output is very small. Scandium is often used to make special glass and lightweight high-temperature resistant alloys.

[0050] Erbium (element symbol Er) is a silvery white lanthanide metal; melting point 1529°C, boiling point 2863°C, density 9.006 g / cm 3 ; Erbium is antiferromagnetic at low temperatures, strongly ferromagnetic at temperatures close to absolute zero, and a superconductor.

[0051] The present application adds a very small amount of at least one of scandium and erbium to the copper-tin alloy, which can modify the copper-tin alloy, improve the morphology and distribution of the Cu-Sn phase, and refine the rare earth elements in the alloy to form nanoparticles or nanocrystals, so that the structure and properties of the copper-tin alloy are significantly changed, and the strength, conductivity and resistance to high-temperature softening are significantly improved.

[0052] The addition of scandium or erbium can form a core-shell structure of CuRE binary phase and CuSnRE ternary phase in the Cu-Sn alloy. On the one hand, it can significantly refine the grains, achieve fine grain strengthening, improve the strength of the alloy, and make the tensile strength of the Cu-Sn alloy reach 750MPa~820MPa; scandium or erbium will form a high melting point primary phase during the melting and casting process. These primary phases will become crystallization cores, increase the nucleation points of the grains, thereby increasing the number of grains and reducing the grain size. Secondly, the addition of scandium or erbium helps the Sn element to precipitate from the copper matrix, thereby reducing the number of solute atoms in the matrix, reducing the content of the Sn element, and improving the electrical conductivity of the alloy. The conductivity reaches 75% IACS~82% IACS. Rare earth elements have a strong affinity with oxygen and sulfur, forming rare earth compounds with a high melting point, strong thermal stability, and low specific gravity, thereby achieving the effects of desulfurization and deoxidation, thereby effectively purifying the melt, improving the purity of the melt, reducing the mixing of impurity elements, and promoting the precipitation of the Sn element, and improving the electrical conductivity of the alloy. Thirdly, the rare earth copper-tin alloy formed has a high melting point, which can significantly increase the high-temperature softening resistance of the alloy, and its softening temperature can reach 550℃~620℃.

[0053] In some embodiments, based on the total mass of the rare earth copper-tin alloy, the mass percentage of tin element is 0.2% to 0.4%, the mass percentage of rare earth element is 0.2% to 0.3%, and the balance is copper element.

[0054] In some embodiments, the rare earth elements include Sc and Er, and in the rare earth copper-tin alloy, the mass ratio of Sc to Er is (1.5-2.5):(1-3).

[0055] In a second aspect, the present application also provides a method for preparing the rare earth copper-tin alloy.

[0056] In some embodiments, the method for preparing the rare earth copper-tin alloy comprises: smelting copper, tin and rare earth elements under the protection of nitrogen or an inert atmosphere, pulling, and obtaining a casting billet;

[0057] The ingot is first subjected to a solution treatment, and then subjected to at least two cold drawing treatments and at least two aging treatments to obtain a rare earth-reinforced copper-tin alloy material;

[0058] Preferably, the at least two cold drawing treatments and the at least two aging treatments include a first cold drawing treatment, a first aging treatment, a second cold drawing treatment, a second aging treatment and a third cold drawing treatment performed sequentially.

[0059] The present application melts and pulls under the protection of an inert atmosphere, reduces the burning loss of Sn and the oxygen content, and realizes the continuous preparation of the ingot. Multiple drawing and multiple aging treatments inhibit Sn segregation and promote the precipitation of Sn elements. More than two aging treatments can produce a large number of deformation twins, and at the same time can further precipitate solute atoms, thereby improving the conductivity of the alloy.

[0060] The preparation method of the rare earth copper-tin alloy is simple and effective, can realize continuous and batch production, and has a high cost-effectiveness.

[0061] In some embodiments, the purity of copper, tin, scandium or erbium is 99.99% or more;

[0062] and / or, the smelting temperature is 1300-1350° C., and the smelting time is 0.5-1 h;

[0063] And / or, the pulling temperature is 1280-1320°C.

[0064] In some embodiments, vacuum evacuation is performed before smelting to a vacuum degree not higher than 10 -1 Pa;

[0065] and / or, after vacuum evacuation, the furnace is washed with inert gas at least twice and then smelting is carried out under the protection of an inert atmosphere;

[0066] Preferably, the inert gas includes nitrogen and / or argon, and the purity of the inert gas is above 99.99%.

[0067] In some embodiments, the solution treatment temperature is 900-1000° C., and the time is 0.5-1.5 h.

[0068] In some embodiments, the cold drawing treatment and the aging treatment satisfy at least one of the following conditions AE:

[0069] A: The first cold drawing process causes the diameter deformation rate of the material to be 70-90%;

[0070] B: The temperature of the first aging treatment is 350-400°C and the time is 0.5-1.5h;

[0071] C: The second cold drawing process causes the diameter deformation rate of the material to be (the average diameter is reduced) 50% to 70%;

[0072] D: The temperature of the second aging treatment is 350-400°C and the time is 0.5-1.5h;

[0073] E: The third cold drawing process causes the diameter deformation rate of the material to be 60% to 80% (the average diameter is reduced).

[0074] In some embodiments, the cold drawing treatment and the aging treatment specifically include: the first cold drawing treatment pulls the average diameter of the material from 18 mm to 3 mm; the temperature of the first aging treatment is 350-400°C, and the time is 0.5-1.5 h; the second cold drawing treatment pulls the average diameter of the material from 3 mm to 1 mm; the temperature of the second aging treatment is 350-400°C, and the time is 0.5-1.5 h; the third cold drawing treatment pulls the average diameter of the material from 1 mm to 0.3 mm.

[0075] The optimum temperature for the first aging treatment is 350°C, and the optimum temperature for the second aging treatment is 400°C.

[0076] The present invention selects three cold drawing processes and adopts specific temperature and time, which can eliminate the work hardening caused by drawing.

[0077] In a third aspect, the present application also provides a use of the rare earth copper-tin alloy or the rare earth copper-tin alloy obtained by the preparation method in cables, transformers, motors or electronic equipment; the cables include high-speed railway contact wires.

[0078] If no specific experimental steps or conditions are specified in the following experiments, the conventional experimental steps or conditions described in the literature in this field can be used. If no manufacturer is specified for the reagents or instruments used, they are all conventional reagent products that can be purchased commercially.

[0079] The diameter deformation rate is calculated by the following formula:

[0080] ε=(d o -d) / d o ×100%

[0081] Among them, ε is the diameter deformation rate; d o ——Diameter of the material before drawing; d——Diameter of the material after drawing.

[0082] Example 1

[0083] The present embodiment provides a rare earth copper-tin alloy and a preparation method thereof. The rare earth copper-tin alloy is composed of copper, tin and a rare earth element (Er element). Based on the total mass of the rare earth copper-tin alloy, the mass percentage of the tin element is 0.3%, the mass percentage of the rare earth element is 0.25%, and the remainder is the copper element.

[0084] The preparation method of the rare earth copper-tin alloy comprises:

[0085] (1) Add Cu, Sn and rare earth elements into a vacuum induction furnace according to the above mass ratio, and the purity of copper, tin or rare earth elements is greater than 99.99%; vacuum evacuation is first performed; vacuum evacuation is performed until the vacuum degree is 10 -1 Pa; wash the furnace with inert gas (nitrogen, purity 99.99%) twice, then heat to 1320℃, smelt for 40min under the protection of inert atmosphere, pour it into the holding furnace through the overflow channel after smelting, adjust the temperature to 1300℃ and then pull it to obtain a 18mm diameter ingot;

[0086] (2) subjecting the ingot obtained in step (1) to a solution treatment at 950° C. for 1 h, and then sequentially subjecting the ingot to a primary cold drawing treatment, a primary aging treatment, a secondary cold drawing treatment, a secondary aging treatment, and a tertiary cold drawing treatment to obtain a rare earth-enhanced copper-tin alloy material;

[0087] The first cold drawing process pulled the average diameter of the solution treated material from 18 mm to 3 mm, with a diameter deformation rate of 83.3%;

[0088] The temperature of the first aging treatment is 370°C and the time is 1h;

[0089] The second cold drawing process pulled the average diameter of the material from 3 mm to 1 mm, and the diameter deformation rate was 66.67%;

[0090] The temperature of the second aging treatment is 370℃ and the time is 1h;

[0091] The third cold drawing process reduces the average diameter of the material from 1 mm to 0.3 mm, with a diameter deformation rate of 70%.

[0092] Example 2

[0093] The present embodiment provides a rare earth copper-tin alloy and a preparation method thereof. The rare earth copper-tin alloy is composed of copper, tin and a rare earth element (Er element). Based on the total mass of the rare earth copper-tin alloy, the mass percentage of the tin element is 0.5%, the mass percentage of the rare earth element is 0.4%, and the remainder is the copper element.

[0094] The preparation method of the rare earth copper-tin alloy comprises:

[0095] (1) Add Cu, Sn and rare earth elements into a vacuum induction furnace according to the above mass ratio, and the purity of copper, tin or rare earth elements is greater than 99.99%; vacuum evacuation is first performed; vacuum evacuation is performed until the vacuum degree is 10 -1Pa; the furnace is washed with inert gas (a mixture of nitrogen and argon with a volume ratio of 1:1, and the purity of the inert gas is greater than 99.99%) for 3 times, and then heated to 1350°C, and smelted for 1 hour under the protection of inert atmosphere. After smelting, it is poured into the holding furnace through the overflow channel, and the temperature is adjusted to 1320°C and then pulled to obtain a 18mm diameter ingot;

[0096] (2) subjecting the ingot obtained in step (1) to a solution treatment at 1000° C. for 1.5 h, and then sequentially subjecting the ingot to a primary cold drawing treatment, a primary aging treatment, a secondary cold drawing treatment, a secondary aging treatment, and a tertiary cold drawing treatment to obtain a rare earth-enhanced copper-tin alloy material;

[0097] The first cold drawing process pulled the average diameter of the solution treated material from 18 mm to 3 mm, with a diameter deformation rate of 83.3%;

[0098] The temperature of the first aging treatment is 400°C and the time is 1.5h;

[0099] The second cold drawing process pulled the average diameter of the material from 3 mm to 1 mm, and the diameter deformation rate was 66.67%;

[0100] The temperature of the second aging treatment is 400°C and the time is 1.5h;

[0101] The third cold drawing process reduces the average diameter of the material from 1 mm to 0.3 mm, with a diameter deformation rate of 70%.

[0102] Example 3

[0103] The present embodiment provides a rare earth copper-tin alloy and a preparation method thereof. The rare earth copper-tin alloy is composed of copper, tin and a rare earth element (Er element). Based on the total mass of the rare earth copper-tin alloy, the mass percentage of the tin element is 0.1%, the mass percentage of the rare earth element is 0.1%, and the remainder is the copper element.

[0104] The preparation method of the rare earth copper-tin alloy comprises:

[0105] (1) Add Cu, Sn and rare earth elements into a vacuum induction furnace according to the above mass ratio, and the purity of copper, tin or rare earth elements is greater than 99.99%; vacuum evacuate the furnace first; vacuum evacuate the furnace until the vacuum degree is 10 -1 Pa; wash the furnace with inert gas (argon, purity greater than 99.99%) twice, then heat to 1300°C, smelt for 0.5h under the protection of inert atmosphere, pour it into the holding furnace through the overflow channel after smelting, adjust the temperature to 1280°C and then pull it to obtain a 18mm diameter ingot;

[0106] (2) subjecting the ingot obtained in step (1) to a solution treatment at 900° C. for 0.5 h, and then sequentially subjecting the ingot to a first cold drawing treatment, a first aging treatment, a second cold drawing treatment, a second aging treatment, and a third cold drawing treatment to obtain a rare earth-enhanced copper-tin alloy material;

[0107] The first cold drawing process pulled the average diameter of the solution treated material from 18 mm to 3 mm, with a diameter deformation rate of 83.3%;

[0108] The temperature of the first aging treatment is 350°C and the time is 0.5h;

[0109] The second cold drawing process pulled the average diameter of the material from 3 mm to 1 mm, and the diameter deformation rate was 66.67%;

[0110] The temperature of the second aging treatment is 350℃ and the time is 0.5h;

[0111] The third cold drawing process reduces the average diameter of the material from 1 mm to 0.3 mm, with a diameter deformation rate of 70%.

[0112] Example 4

[0113] The present embodiment provides a rare earth copper-tin alloy and a preparation method thereof. The rare earth copper-tin alloy is composed of copper, tin and a rare earth element (Sc element). Based on the total mass of the rare earth copper-tin alloy, the mass percentage of the tin element is 0.3%, the mass percentage of the rare earth element is 0.25%, and the remainder is the copper element.

[0114] The preparation method of the rare earth copper-tin alloy comprises:

[0115] (1) Add Cu, Sn and rare earth elements into a vacuum induction furnace according to the above mass ratio, and the purity of copper, tin or rare earth elements is greater than 99.99%; vacuum evacuate the furnace first; vacuum evacuate the furnace until the vacuum degree is 10 -1 Pa; wash the furnace with inert gas (argon, purity greater than 99.99%) twice, then heat to 1320°C, smelt for 40 minutes under the protection of inert atmosphere, pour it into the holding furnace through the overflow channel after smelting, adjust the temperature to 1300°C and then pull it to obtain a 18mm diameter ingot;

[0116] (2) subjecting the ingot obtained in step (1) to a solution treatment at 950° C. for 1 h, and then to a cold drawing treatment and an aging treatment in sequence to obtain a rare earth-enhanced copper-tin alloy material;

[0117] The first cold drawing process pulled the average diameter of the solution treated material from 18 mm to 3 mm, with a diameter deformation rate of 83.3%;

[0118] The temperature of the first aging treatment is 370℃ and the time is 1h.

[0119] The second cold drawing process pulled the average diameter of the material from 3 mm to 1 mm, and the diameter deformation rate was 66.67%;

[0120] The temperature of the second aging treatment is 370℃ and the time is 1h;

[0121] The third cold drawing process reduces the average diameter of the material from 1 mm to 0.3 mm, with a diameter deformation rate of 70%.

[0122] Example 5

[0123] The present embodiment provides a rare earth copper-tin alloy and a preparation method thereof, wherein the rare earth copper-tin alloy is composed of copper, tin and rare earth elements; the rare earth elements are Sc and Er; based on the total mass of the rare earth copper-tin alloy, the mass percentage of the tin element is 0.3%, the mass percentage of the rare earth element is 0.25%, and the remainder is the copper element; the mass ratio of Sc to Er is 1:1.

[0124] The preparation method of the rare earth copper-tin alloy comprises:

[0125] (1) Add Cu, Sn and rare earth elements into a vacuum induction furnace according to the above mass ratio, and the purity of copper, tin or rare earth elements is greater than 99.99%; vacuum evacuate the furnace first; vacuum evacuate the furnace until the vacuum degree is 10 -1 Pa; wash the furnace with inert gas (argon, purity greater than 99.99%) twice, then heat to 1320°C, smelt for 40 minutes under the protection of inert atmosphere, pour it into the holding furnace through the overflow channel after smelting, adjust the temperature to 1300°C and then pull it to obtain a 18mm diameter ingot;

[0126] (2) The ingot obtained in step (1) is first subjected to a solution treatment at 950° C. for 1 h to obtain a rare earth-reinforced copper-tin alloy material.

[0127] The first cold drawing process pulled the average diameter of the solution treated material from 18 mm to 3 mm, with a diameter deformation rate of 83.3%;

[0128] The temperature of the first aging treatment is 370℃ and the time is 1h.

[0129] The second cold drawing process pulled the average diameter of the material from 3 mm to 1 mm, and the diameter deformation rate was 66.67%;

[0130] The temperature of the second aging treatment is 370℃ and the time is 1h;

[0131] The third cold drawing process reduces the average diameter of the material from 1 mm to 0.3 mm, with a diameter deformation rate of 70%.

[0132] Comparative Example 1

[0133] This comparative example provides a copper-tin alloy and a preparation method thereof, wherein the copper-tin alloy comprises copper and tin; based on the total mass of the copper-tin alloy, the mass percentage of the tin element is 0.3%, and the remainder is the copper element;

[0134] The preparation method of the copper-tin alloy comprises:

[0135] (1) Add Cu and Sn into a vacuum induction furnace in the above mass ratio, and the purity of copper and tin is greater than 99.99%; vacuum evacuate the furnace first; vacuum evacuate the furnace to a vacuum degree of 10 -1 Pa; wash the furnace with inert gas (argon, purity greater than 99.99%) twice, then heat to 1320°C, smelt for 40 minutes under the protection of inert atmosphere, pour it into the holding furnace through the overflow channel after smelting, adjust the temperature to 1300°C and then pull it to obtain a 18mm diameter ingot;

[0136] (2) subjecting the ingot obtained in step (1) to a solution treatment at 950° C. for 1 h, and then sequentially subjecting the ingot to a primary cold drawing treatment, a primary aging treatment, a secondary cold drawing treatment, a secondary aging treatment, and a tertiary cold drawing treatment to obtain a rare earth-enhanced copper-tin alloy material;

[0137] The first cold drawing process pulled the average diameter of the solution treated material from 18 mm to 3 mm, with a diameter deformation rate of 83.3%;

[0138] The temperature of the first aging treatment is 370°C and the time is 1h;

[0139] The second cold drawing process pulled the average diameter of the material from 3 mm to 1 mm, and the diameter deformation rate was 66.67%;

[0140] The temperature of the second aging treatment is 370℃ and the time is 1h;

[0141] The third cold drawing process reduces the average diameter of the material from 1 mm to 0.3 mm, with a diameter deformation rate of 70%.

[0142] Comparative Example 2

[0143] This comparative example provides a rare earth copper-tin alloy and a preparation method thereof. The only difference between this comparative example and Example 5 is that the mass percentage content of the tin element is 0.08%.

[0144] Comparative Example 3

[0145] This comparative example provides a rare earth copper-tin alloy and a preparation method thereof. The comparative example is different from Example 5 in that the mass percentage content of the tin element is 0.6%.

[0146] Comparative Example 4

[0147] This comparative example provides a rare earth copper-tin alloy and a preparation method thereof. Compared with Example 5, this comparative example is different only in that the mass percentage of the rare earth element is 0.08% (the mass ratio of Sc to Er in the rare earth element is 1:1).

[0148] Comparative Example 5

[0149] This comparative example provides a rare earth copper-tin alloy and a preparation method thereof. Compared with Example 5, this comparative example is different only in that the mass percentage of the rare earth element is 0.5% (the mass ratio of Sc to Er in the rare earth element is 1:1).

[0150] Comparative Example 6

[0151] This comparative example provides a rare earth copper-tin alloy and a preparation method thereof. Compared with Example 5, this comparative example is different only in that: the rare earth copper-tin alloy is composed of copper, tin, rare earth elements and phosphorus; based on the total mass of the rare earth copper-tin alloy, the mass percentage of tin element is 0.3%, the mass percentage of rare earth element is 0.25% (the mass ratio of Sc and Er in the rare earth elements is 1:1), the mass percentage of phosphorus is 0.16%, and the balance is copper element.

[0152] Test Example 1

[0153] The performance of the tin-copper alloys prepared in Examples 1-5 and Comparative Examples 1-5 was tested, and the results are shown in Table 1:

[0154] Table 1 Performance test results

[0155]

[0156] As can be seen from the above table, the tensile strength of the rare earth-enhanced copper-tin alloy materials of Examples 1-5 reaches 750MPa-820MPa; the conductivity reaches 75%IACS-82%IACS; and the softening temperature can reach 550℃-620℃. Comparative Example 1 does not add rare earth elements, thereby reducing the tensile strength and softening temperature; Comparative Example 2 has a small amount of tin added, thereby reducing the tensile strength and softening temperature; Comparative Example 3 has a large amount of tin added, and the tensile strength, conductivity and softening temperature are all low; Comparative Example 4 has a small amount of rare earth elements added, and the tensile strength and softening temperature are all low; Comparative Example 5 has a large amount of tin added, and the conductivity and softening temperature are all low; Comparative Example 6 adds phosphorus, and the tensile strength, conductivity and softening temperature are all low. The rare earth copper-tin alloy provided in the present invention has high tensile strength, conductivity and softening temperature at the same time, and can be used in cables, transformers, motors or electronic equipment.

[0157] Test Example 2

[0158] The ingot obtained in Example 5 was observed under SEM, and images thereof were obtained with a magnification of 1000 times ( Figure 1 ) and the image magnified 300 times ( Figure 2 ),from Figure 1 and Figure 2 It can be seen that the addition of rare earth elements (Sc and Er) can effectively refine the grains and achieve the effect of fine grain strengthening.

[0159] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection created by this application.

Claims

1. A rare earth copper-tin alloy, characterized in that: The rare earth copper-tin alloy is composed of copper, tin and rare earth elements; the rare earth elements include scandium and / or erbium; Based on the total mass of the rare earth copper-tin alloy, the mass percentage of tin element is 0.1% to 0.5%, the mass percentage of rare earth element is 0.1% to 0.4%, and the balance is copper element.

2. The rare earth copper-tin alloy according to claim 1, characterized in that: Based on the total mass of the rare earth copper-tin alloy, the mass percentage of tin element is 0.2% to 0.4%, the mass percentage of rare earth element is 0.2% to 0.3%, and the balance is copper element.

3. The rare earth copper-tin alloy according to claim 1 or 2, characterized in that: The rare earth elements include scandium and erbium. In the rare earth copper-tin alloy, the mass ratio of scandium to erbium is (1.5-2.5): (1-3).

4. A method for preparing the rare earth copper-tin alloy according to any one of claims 1 to 3, characterized in that: include: The copper, tin and rare earth elements are smelted and pulled under the protection of nitrogen or inert atmosphere to obtain a casting billet; The ingot is first subjected to a solution treatment, and then subjected to at least two cold drawing treatments and at least two aging treatments to obtain a rare earth-reinforced copper-tin alloy material; Optionally, the at least two cold drawing treatments and the at least two aging treatments include a first cold drawing treatment, a first aging treatment, a second cold drawing treatment, a second aging treatment and a third cold drawing treatment performed sequentially.

5. The method for preparing the rare earth copper-tin alloy according to claim 4, characterized in that: The purity of copper, tin, scandium or erbium is 99.99% or more; and / or, the smelting temperature is 1300-1350° C., and the smelting time is 0.5-1 h; And / or, the pulling temperature is 1280-1320°C.

6. The method for preparing the rare earth copper-tin alloy according to claim 4, characterized in that: Before smelting, vacuum evacuate to a vacuum degree not higher than 10 -1 Pa; Optionally, after vacuum evacuation, the furnace is washed with inert gas at least twice and then smelting is carried out under the protection of inert atmosphere; Optionally, the inert gas includes nitrogen and / or argon, and the purity of the inert gas is >99.99%.

7. The method for preparing the rare earth copper-tin alloy according to claim 4, characterized in that: The solution treatment temperature is 900-1000° C. and the time is 0.5-1.5 h.

8. The method for preparing the rare earth copper-tin alloy according to claim 4, characterized in that: The cold drawing treatment and the aging treatment satisfy at least one of the following conditions A to E: A: The first cold drawing process causes the diameter deformation rate of the material to be 70% to 90%; B: The temperature of the first aging treatment is 350-400°C and the time is 0.5-1.5h; C: The second cold drawing process causes the diameter deformation rate of the material to be 50% to 70%; D: The temperature of the second aging treatment is 350-400°C and the time is 0.5-1.5h; E: The third cold drawing process causes the diameter deformation rate of the material to be 60% to 80%.

9. The method for preparing the rare earth copper-tin alloy according to claim 4, characterized in that: The first cold drawing process pulls the average diameter of the material from 18 mm to 3 mm; the second cold drawing process pulls the average diameter of the material from 3 mm to 1 mm; and the third cold drawing process pulls the average diameter of the material from 1 mm to 0.3 mm.

10. Use of the rare earth copper-tin alloy according to any one of claims 1 to 3 or the rare earth copper-tin alloy obtained by the preparation method according to any one of claims 4 to 9 in cables, transformers, motors or electronic equipment.

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