CN111549253A - Rare earth copper-iron alloy, preparation method and application - Google Patents

Abstract

The invention provides a rare earth copper-iron alloy, a preparation method and application thereof, belonging to the technical field of non-ferrous metal materials. The rare earth copper-iron alloy provided by the invention comprises 0.25-0.5% of rare earth elements, 8-20% of Fe and the balance of Cu in percentage by mass. According to the invention, rare earth elements are added into the Cu-Fe alloy, so that the effects of purifying the alloy, refining crystal grains and promoting Fe phase precipitation can be achieved, and the conductivity of the Cu-Fe alloy is improved; the content of iron element in the alloy is high, the consumption of copper is low, and the production cost is reduced; the dosage of the rare earth element is more, and the influence of the iron element on the conductivity of the alloy can be reduced. The results of the examples show that the conductivity of the rare earth copper-iron alloy provided by the invention reaches more than 56% IACS, the tensile strength reaches more than 768MPa, and the elongation reaches more than 2.9%.

Description

A kind of rare earth copper-iron alloy and preparation method and application

technical field

The invention relates to the technical field of non-ferrous metal materials, in particular to a rare earth copper-iron alloy and a preparation method and application.

Background technique

Because of its good electrical and thermal conductivity, good corrosion resistance, as well as easy casting, easy plastic processing and good weldability, copper alloy has become an important material in the current industry and is widely used in electronics, electromechanical, aviation, etc. , aerospace and other departments. With the increasing requirements for the strength and conductivity of conductive materials, such as strong magnetic field magnet coils, large-scale integrated circuit lead frames and overhead wires for high-speed electrical locomotives, how to greatly improve the performance of electrical conductivity and thermal conductivity as little as possible The strength of materials has become a research hotspot. Cu-Fe alloys have attracted extensive attention due to their good comprehensive properties, low production costs and environmental protection. However, when the Fe content of the second phase component in the Cu-Fe alloy is high, the addition of Fe atoms is bound to greatly reduce the electrical conductivity of the copper matrix. How to reduce the solid solubility of Fe in the copper matrix has become a key technology to improve the electrical conductivity of the alloy. question.

There are two main methods for improving the electrical conductivity of Cu-Fe alloys in the current industry:

1. Change the preparation method of Cu-Fe alloy. For example, in the patent CN110923693A, the cold spraying process is used to prepare Cu-Fe alloy. During the preparation process, no melting process occurs, and no Fe atoms are dissolved in Cu. The purity of the copper matrix is beneficial to significantly improve the electrical conductivity of the alloy. However, this preparation method is mainly used for 3D printing of complex-shaped parts. Compared with the traditional casting method, the yield is low and cannot be mass-produced.

2. Adjust element composition in Cu-Fe alloy, such as "Effect of Boron and Cerium on Microstructure and Properties of Cu-Fe-P Alloy" (Chinese Journal of Rare Earth, State Key Laboratory of Metal Matrix Composites, Shanghai Jiaotong University, Lu Deping ), it is recorded that P element is added to Cu-Fe alloy to form Cu-Fe-P alloy, and then rare earth element and boron element are added to purify the material and improve the conductivity of the alloy. However, the content of Fe element in Cu-Fe-P alloy is relatively low, generally 0.1 to 2.3%, while the content of iron in Cu-Fe alloy is 8 to 20%. At the same time, the mechanical properties of the alloy will be greatly deviated. At the same time, the addition of rare earth elements in the Cu-Fe-P alloy cannot exceed 0.2 wt. Society's requirements for strength and electrical conductivity of alloy materials. Although the patent CN1417357A records that the content of rare earth elements in the copper alloy can be increased to 0.3%, it is necessary to add Zn and Ti elements to balance the comprehensive properties of the alloy, thereby improving the conductivity of the copper alloy. The types of middle elements are complex, Zn and Ti are expensive, and the cost of copper alloys is high, which reduces the competitiveness of enterprises.

Therefore, it has become a technical problem to be solved to provide a Cu-Fe alloy with low cost, good electrical conductivity and mechanical properties.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a rare earth copper-iron alloy and a preparation method and application thereof. The rare-earth copper-iron alloy provided by the present invention has low cost, excellent electrical conductivity, high tensile strength and hardness, and can be applied to the fields of electronics, electromechanical, aviation and aerospace. .

In order to achieve the above-mentioned purpose of the invention, the present invention provides the following technical solutions:

The invention provides a rare earth copper-iron alloy, which in terms of mass percentage, comprises 0.25-0.5% of rare-earth elements, 8-20% of Fe and the balance of Cu.

Preferably, in terms of mass percentage, it includes 0.3-0.45% of rare earth elements, 10-18% of Fe and the balance of Cu.

Preferably, 0.4% of rare earth elements, 15% of Fe and the balance of Cu are included in terms of mass percentage.

Preferably, the rare earth element is one or more of Ce, La and Y.

The present invention also provides the preparation method of the rare earth copper-iron alloy described in the above technical solution, comprising the following steps:

(1) casting the copper source, the iron source and the rare earth raw materials after smelting to obtain an alloy ingot;

(2) After successively performing hot rolling, solution treatment, cold rolling, aging treatment and finish rolling on the alloy ingot obtained in the step (1), a rare earth copper-iron alloy is obtained.

Preferably, in the step (2), the temperature of the hot rolling is 850-950° C., and the total deformation of the hot rolling is 20-50%.

Preferably, in the step (2), the holding temperature of the solution treatment is 900-1100° C., and the holding time of the solution treatment is 10-200 min.

Preferably, the total deformation of cold rolling in the step (2) is 60-90%.

Preferably, in the step (2), the holding temperature of the aging treatment is 400-600° C., and the holding time of the aging treatment is 1-24 h.

The present invention also provides applications of the rare earth copper-iron alloy described in the above technical solution or the rare earth copper-iron alloy prepared by the preparation method described in the above technical solution in the fields of electronics, electromechanics, aviation and aerospace.

The invention provides a rare earth copper-iron alloy, which in terms of mass percentage, comprises 0.25-0.5% of rare-earth elements, 8-20% of Fe and the balance of Cu. The invention uses the Cu-Fe alloy as the matrix, uses a certain amount of rare earth elements to purify the impurities in the alloy, reduces the lattice distortion caused by the solid solution impurities, reduces the elastic scattering of the lattice to electrons, improves the electrical conductivity of the material, and at the same time promotes Fe The precipitation of the phase reduces the solid solubility of Fe atoms in the copper matrix, reduces the lattice distortion of the copper matrix, and improves the electrical conductivity of the Cu-Fe alloy; in addition, the rare earth can refine the grains and Fe phase dendrites structure and promote the uniform distribution of Fe phase in the matrix, which is beneficial to the improvement of the mechanical properties of the material; the high content of iron in the alloy can reduce the amount of copper and the production cost; the amount of rare earth elements is large, which can reduce the effect of iron on copper. The influence of electrical conductivity to improve the electrical conductivity of the alloy. The results of the examples show that the electrical conductivity of the rare earth copper-iron alloy provided by the present invention reaches more than 56% IACS, the tensile strength reaches more than 768 MPa, and the elongation reaches more than 2.9%.

Description of drawings

FIG. 1 is a flow chart of the preparation process of the rare earth copper-iron alloy provided in Examples 1 to 4 of the present invention.

Detailed ways

The invention provides a rare earth copper-iron alloy, which in terms of mass percentage, comprises 0.25-0.5% of rare-earth elements, 8-20% of Fe and the balance of Cu.

In terms of mass percentage, the rare earth copper-iron alloy provided by the present invention includes 0.25-0.5% rare earth element, preferably 0.3-0.45%, more preferably 0.4%. In the present invention, the rare earth element is preferably one or more of Ce, La and Y, more preferably Ce.

In terms of mass percentage, the rare earth copper-iron alloy provided by the present invention comprises 8-20% Fe, preferably 10-18%, more preferably 14%.

In the present invention, the mass percentage of iron and rare earth elements in the copper alloy is controlled within the above range, the iron element can form a Cu-Fe alloy matrix with the copper element, and a certain amount of rare earth elements is used to purify the impurities in the alloy, thereby reducing the impurities caused by solid solution impurities. The lattice distortion reduces the elastic scattering of the lattice to electrons, improves the electrical conductivity of the material, and at the same time promotes the precipitation of Fe phase, reduces the solid solubility of Fe atoms in the copper matrix, reduces the lattice distortion of the copper matrix, and improves the The electrical conductivity of Cu-Fe alloy; in addition, rare earth can refine the grain and Fe phase dendrite structure, promote the uniform distribution of Fe phase in the matrix, which is beneficial to the improvement of the mechanical properties of the material; the high content of iron in the alloy can reduce copper The amount of rare earth element is more, which can reduce the influence of iron element on the electrical conductivity of copper and improve the electrical conductivity of the alloy.

The present invention also provides the preparation method of the rare earth copper-iron alloy described in the above technical solution, comprising the following steps:

(1) casting the copper source, the iron source and the rare earth raw materials after smelting to obtain an alloy ingot;

(2) After successively performing hot rolling, solution treatment, cold rolling, aging treatment and finish rolling on the alloy ingot obtained in the step (1), a rare earth copper-iron alloy is obtained.

In the present invention, the copper source, the iron source and the rare earth raw materials are smelted and cast to obtain an alloy ingot. The present invention has no special limitation on the smelting equipment, and a smelting equipment well-known to those skilled in the art can be used. In the present invention, the smelting equipment is preferably an intermediate frequency electromagnetic induction furnace.

In the present invention, the copper source is preferably electrolytic copper; the purity of the electrolytic copper is preferably ≥99.9%, more preferably 99.9%.

In the present invention, the iron source is preferably pure iron; the purity of the pure iron is preferably ≥99.9%, more preferably 99.9%.

In the present invention, the rare earth raw material is preferably a rare earth master alloy, more preferably a copper rare earth master alloy; the content of rare earth elements in the copper rare earth master alloy is preferably 3-7 wt %, more preferably 5 wt %.

The invention uses electrolytic copper and pure iron as raw materials, which can reduce the content of impurities in the rare earth copper-iron alloy, and uses the rare earth intermediate alloy as the raw material, which does not introduce impurity elements, and at the same time, the intermediate alloy can promote the uniform distribution of rare earth elements in the alloy, so as to achieve The effect of purifying the alloy, refining the grains and promoting the precipitation of Fe phase further improves the electrical conductivity and mechanical properties of the rare earth copper-iron alloy.

The sources of the copper source, iron source and rare earth raw material are not particularly limited in the present invention, and commercially available products well known to those skilled in the art may be used.

In the present invention, the smelting of the copper source, iron source and rare earth raw material is preferably as follows: first smelting electrolytic copper and pure iron to obtain a copper-iron alloy solution; then adding a copper rare-earth master alloy to the copper-iron alloy solution The second smelting is performed to obtain a rare earth copper-iron alloy solution.

In the present invention, electrolytic copper and pure iron are preferably first smelted to obtain a copper-iron alloy solution. In the present invention, the temperature of the first smelting is preferably 1250-1400°C, more preferably 1280-1350°C; the time of the first smelting is preferably 10-30 min, more preferably 20 min. In the present invention, the electrolytic copper and pure iron are first smelted, and the smelting time is relatively long, which can ensure that the copper element and the iron element are evenly mixed.

After the copper-iron alloy solution is obtained, the present invention preferably adds a copper-rare earth intermediate alloy to the copper-iron alloy solution for second smelting to obtain a rare-earth copper-iron alloy solution. In the present invention, the temperature of the second smelting is preferably 1250-1400°C, more preferably 1280-1350°C; the time of the second smelting is preferably 2-5 minutes, more preferably 3 minutes. In the present invention, the copper-rare earth intermediate alloy is added into the copper-iron alloy solution for the second smelting, which can reduce the smelting time and reduce the burning loss of rare earth elements.

The present invention does not have a special limitation on the specific casting process, and a casting process well known to those skilled in the art can be used. In the present invention, the casting temperature is preferably 1250-1400°C, more preferably 1280-1350°C, and most preferably 1290-1310°C. The present invention has no special limitation on the casting mold, and a mold well known to those skilled in the art may be used. In the present invention, the casting mold is preferably a graphite mold.

After the casting is completed, the present invention preferably performs peeling treatment on the cast product to obtain an alloy ingot. The operation of the peeling treatment is not particularly limited in the present invention, and the technical solution of the peeling treatment well-known to those skilled in the art can be adopted. The invention can remove the oxide layer on the surface of the alloy ingot by performing peeling treatment on the alloy ingot, so as to prevent impurity elements from affecting the performance of the alloy.

After the alloy ingot is obtained, the present invention sequentially performs hot rolling, solution treatment, cold rolling, aging treatment and finish rolling on the alloy ingot to obtain a rare earth copper-iron alloy.

In the present invention, the hot rolling is preferably performed by subjecting the alloy ingot to a homogenization treatment at a hot rolling temperature, followed by rolling. In the present invention, the time of the homogenization treatment is preferably 1 to 5 hours, more preferably 3 hours. By performing the homogenization treatment in the present invention, the chemical composition in the alloy can be made more uniform, thereby laying a foundation for the subsequent hot rolling treatment.

In the present invention, the temperature of the hot rolling is preferably 850-950°C, more preferably 900°C; the total deformation of the hot-rolling is preferably 20-50%, more preferably 30-40%. The invention can break the Fe phase dendrites in the alloy by performing the hot rolling process, so that it can be transformed into a fine granular structure, which is beneficial to the structure refinement and the formation of the micro-enhancing phase in the subsequent deformation process.

The present invention does not have a special limitation on the hot rolling equipment, and the equipment well known to those skilled in the art can be used. In the present invention, the hot rolling equipment is preferably a hot rolling mill.

After the hot rolling is completed, the present invention preferably heats the hot rolled product directly to the holding temperature of the solution treatment without cooling.

In the present invention, the holding temperature of the solution treatment is preferably 900-1100°C, more preferably 920-1000°C, and most preferably 950°C; the holding time of the solution treatment is preferably 10-200min, more preferably It is 50～190min, most preferably 180min. The present invention can fully dissolve the Fe phase in the Cu matrix by performing the solid solution treatment, thereby enhancing the plasticity of the alloy, which is beneficial to the subsequent cold rolling and aging treatment.

The present invention does not have a special limitation on the equipment for the solution treatment, and equipment well known to those skilled in the art may be used. In the present invention, the equipment for the solution treatment is preferably a heat treatment furnace.

In the present invention, the cooling method of the solution treatment is preferably quenching cooling. The present invention does not specifically limit the specific operation of the quenching and cooling, and a quenching and cooling process well known to those skilled in the art can be used.

In the present invention, the total deformation amount of the cold rolling is preferably 60 to 90%, and more preferably 80%. The present invention has no special limitation on the cold rolling process, and a cold rolling process well known to those skilled in the art can be used. The invention can make the Fe phase in the alloy gradually finer and form the oriented fiber reinforcement phase through the cold rolling process.

In the present invention, the holding temperature of the aging treatment is preferably 400-600°C, more preferably 500°C; the holding time of the aging treatment is preferably 1-24h, more preferably 5-20h, and more preferably 10-15h. The invention can adjust the comprehensive properties of the final deformed alloy through aging treatment, so as to obtain a high-strength and high-conductivity Cu-Fe alloy.

After the aging treatment is completed, in the present invention, preferably, the product of the aging treatment is directly subjected to final rolling at the holding temperature of the aging treatment without cooling. In the present invention, the total deformation of the finish rolling is preferably 30 to 60%, and more preferably 50%. The present invention does not specifically limit the process of the finishing rolling, and a rolling process well known to those skilled in the art can be used. The invention can control the grain size and crystal phase structure in the alloy by controlling the temperature and total deformation of the final rolling, so that the alloy has excellent mechanical properties.

After finishing rolling, the present invention preferably cools the product of finishing rolling to obtain rare earth copper-iron alloy. In the present invention, the end temperature of the cooling is preferably room temperature. The present invention does not have a special limitation on the cooling method, and the alloy cooling process well known to those skilled in the art can be used.

In the embodiment of the present invention, the process flow of the preparation method of the rare earth copper-iron alloy is preferably as shown in FIG. 1 . First, raw material preparation and batching are performed, and the prepared raw materials are sequentially smelted and cast to obtain an alloy ingot, and then the alloy is The ingot is successively subjected to hot rolling solution treatment, cold rolling, aging treatment and finish rolling to obtain a rare earth copper-iron alloy.

The preparation method provided by the invention is a melting and casting method, the preparation process is simple, the cost is low, and it is suitable for industrial large-scale production, thereby realizing the application of rare earth copper-iron alloys in high-magnetic field magnet coils, large-scale integrated circuit lead frames and overhead wires of high-speed electric locomotives, etc. wide application.

The present invention also provides applications of the rare earth copper-iron alloy described in the above technical solution or the rare earth copper-iron alloy prepared by the preparation method described in the above technical solution in the fields of electronics, electromechanics, aviation and aerospace. In the present invention, the electronic, electromechanical, aviation and aerospace fields are preferably strong magnetic field magnet coils, large scale integrated circuit lead frames and overhead wires for high-speed electrical locomotives.

The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some, but not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

Example 1

The composition of the rare earth copper-iron alloy is 0.05% Ce, 14% Fe and 85.95% Cu in terms of mass percentage.

The preparation method is as follows:

(1) Ingredients: the mass percentage is 85% electrolytic copper, 14% pure iron and 1% copper rare earth master alloy (Cu-5wt%Ce) to configure the alloy composition;

(2) Smelting: first mix electrolytic copper and pure iron, put them into an intermediate frequency electromagnetic induction furnace, smelt according to the conventional smelting process of Cu-Fe series materials, smelt for 20 minutes after melting, then add copper rare earth master alloy, smelt for 3 minutes, Cast into a graphite mold within the range of 1300 °C, and obtain an alloy ingot after peeling;

(3) Hot rolling: The alloy ingot is heated to a range of 900°C for homogenization treatment, kept for 3 hours, and then hot rolled with a total deformation of 50% at a temperature of 900°C.

(4) Solution treatment: put the hot-rolled product into a heat treatment furnace, keep the temperature at 950 ° C for 180 min, and then perform quenching and cooling;

(5) Cold rolling: rolling the solution-treated product with a total deformation of 80%;

(6) Aging treatment: the cold-rolled product is heated to 500°C and kept for 1h;

(7) Final rolling: After the aging-treated product is rolled with a total deformation of 60% at 500° C., a rare earth copper-iron alloy is obtained.

Example 2

The composition of the rare earth copper-iron alloy is 0.1% Ce, 14% Fe and 85.9% Cu in terms of mass percentage.

In terms of mass percentage, the raw materials of the rare earth copper iron alloy are 14% pure iron, 84% electrolytic copper and 2% copper rare earth master alloy (Cu-5wt% Ce).

The preparation method is the same as that of Example 1.

Example 3

The composition of the rare earth copper-iron alloy is 0.2% Ce, 14% Fe and 85.8% Cu in terms of mass percentage.

In terms of mass percentage, the raw materials of the rare earth copper iron alloy are 14% pure iron, 82% electrolytic copper and 4% copper rare earth master alloy (Cu-5wt% Ce).

The preparation method is the same as that of Example 1.

Example 4

The composition of the rare earth copper-iron alloy is 0.2% Ce, 14% Fe and 85.8% Cu in terms of mass percentage.

In terms of mass percentage, the raw materials of the rare earth copper iron alloy are 14% pure iron, 82% electrolytic copper and 4% copper rare earth master alloy (Cu-5wt% Ce).

In the preparation method, the temperature of the aging treatment in step (6) is 450° C., and the remaining steps are the same as those in Example 3.

Comparative Example 1

The composition of the copper-iron alloy is 14% Fe and 86% Cu in terms of mass percentage.

The preparation method is as follows:

(1) Ingredients: the mass percentage of 86% electrolytic copper and 14% pure iron are configured into alloy components;

(2) Smelting: first mix electrolytic copper and pure iron, put them into an intermediate frequency electromagnetic induction furnace, smelt according to the conventional smelting process of Cu-Fe series materials, smelt for 20 minutes after melting, and cast them into a graphite mold at 1300 °C After peeling, the alloy ingot is obtained;

(3) Hot rolling: The alloy ingot is heated to a range of 900° C. for homogenization treatment, kept for 3 hours, and then rolled with a total deformation of 50%.

(4) Solution treatment: put the hot-rolled product into a heat treatment furnace, keep the temperature at 950 ° C for 90 min, and then perform quenching and cooling;

(5) Cold rolling: rolling the solution-treated product with a total deformation of 80%;

(6) Aging treatment: the cold-rolled product is heated to 500°C and kept for 1h;

(7) Final rolling: After the aging-treated product is rolled with a total deformation of 60% at 500° C., a copper-iron alloy is obtained.

The properties of the rare earth copper-iron alloys prepared in Examples 1 to 4 and the copper-iron alloy prepared in Comparative Example 1 were tested, and the results are shown in Table 1.

Table 1 Performance parameters of the rare earth copper-iron alloys prepared in Examples 1-4 and the copper-iron alloy prepared in Comparative Example 1

alloy composition Tensile strength (MPa) Elongation (%) Conductivity (%IACS) Example 1 778 3.0 58 Example 2 800 3.2 62 Example 3 825 3.1 60 Example 4 768 2.9 56 Comparative Example 1 760 2.8 55

It can be seen from Table 1 that compared with the copper-iron alloy prepared in Comparative Example 1, the rare-earth copper-iron alloys prepared in Examples 1 to 4 have excellent mechanical properties and electrical conductivity. It can reach more than 768MPa, and the elongation rate reaches more than 2.9%, which can be widely used in strong magnetic field magnet coils, large-scale integrated circuit lead frames and overhead wires of high-speed electric locomotives.

The above are only the preferred embodiments of the present invention. It should be pointed out that for those skilled in the art, without departing from the principles of the present invention, several improvements and modifications can be made. It should be regarded as the protection scope of the present invention.

Claims (10)

1. The rare earth copper-iron alloy comprises, by mass, 0.25-0.5% of rare earth elements, 8-20% of Fe and the balance of Cu.

2. The rare earth-copper-iron alloy according to claim 1, comprising 0.3 to 0.45% by mass of the rare earth element, 10 to 18% by mass of Fe, and the balance of Cu.

3. The rare earth-copper-iron alloy according to claim 1, comprising, in mass%, 0.4% of rare earth elements, 15% of Fe and the balance of Cu.

4. The rare earth-copper-iron alloy according to any one of claims 1 to 3, wherein the rare earth element is one or more of Ce, La and Y.

5. A method of producing a rare earth-copper-iron alloy as claimed in any one of claims 1 to 4, comprising the steps of:

(1) smelting a copper source, an iron source and a rare earth raw material, and then casting to obtain an alloy ingot;

(2) and (2) sequentially carrying out hot rolling, solution treatment, cold rolling, aging treatment and final rolling on the alloy ingot obtained in the step (1) to obtain the rare earth copper-iron alloy.

6. The manufacturing method according to claim 5, wherein the temperature of the hot rolling in the step (2) is 850 to 950 ℃, and the total deformation amount of the hot rolling is 20 to 50%.

7. The production method according to claim 5, wherein the temperature for the solution treatment in the step (2) is 900 to 1100 ℃ and the time for the solution treatment is 10 to 200 min.

8. The manufacturing method according to claim 5, wherein the total deformation amount of the cold rolling in the step (2) is 60-90%.

9. The preparation method according to claim 5, wherein the temperature for the aging treatment in the step (2) is 400-600 ℃, and the time for the aging treatment is 1-24 h.

10. Use of the rare earth copper-iron alloy according to any one of claims 1 to 4 or the rare earth copper-iron alloy prepared by the preparation method according to any one of claims 5 to 9 in the fields of electronics, electromechanics, aviation and aerospace.

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