High-strength heat-resistant aluminum alloy conductor material and preparation method thereof

Abstract

The invention belongs to the field of alloys, and particularly discloses a high-strength heat-resistant aluminum alloy conductor material and a preparation method thereof. The aluminum alloy conductor material is prepared from the following components in percentage by mass: 0.5 to 1.2 percent of Fe, 0.10 to 0.15 percent of Zr, 0.01 to 0.03 percent of B, 0.01 to 0.04 percent of RE, 0.005 to 0.01 percent of Sr, less than or equal to 0.15 percent of inevitable impurities and the balance of Al. RE is selected from at least one of La and Ce. The aluminum alloy conductor material has high iron content, and the type, morphology and distribution of an iron-rich phase in aluminum alloy are improved by introducing low-content Sr and RE elements, so that the aluminum alloy conductor material has high room-temperature tensile strength, excellent electric conductivity and good high-temperature resistance.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of alloys, and particularly relates to a high-strength heat-resistant aluminum alloy wire material and a preparation method thereof. BACKGROUND

[0002] Heat-resistant aluminum alloy wires become key materials for large-capacity power transmission lines due to their excellent electrical conductivity, high-temperature mechanical properties, and creep resistance. Traditional aluminum wires are prone to softening at high temperatures, which limits the current-carrying capacity. To improve the heat resistance of aluminum alloy wires, trace amounts of alloying elements such as Zr, Fe, and rare earth elements are added to form high-melting-point dispersed phases, significantly improving their heat resistance and strength. The addition of appropriate amounts of Zr can form metastable Al3Zr and other nano precipitates, which are beneficial to improving the strength and thermal stability of the alloy and have good application prospects. However, due to the solubility of Zr in aluminum alloys, the electrical conductivity of the alloy is reduced. In addition, as aluminum alloy wires enter the recycling link, steel cores and other materials are inevitably introduced into the wires, increasing the Fe content and forming coarse Fe-rich phases that significantly reduce the plasticity and electrical conductivity of the wires, making it impossible to achieve level utilization.

[0003] CN115798778A discloses a high-conductivity heat-resistant aluminum alloy wire and a preparation method thereof. The wire mainly contains 0.08-0.12% Zr, 0.1-0.15% Si, 0.12-0.17% Fe, and 0.05-0.1% RE. It uses La and Ce mixed rare earths to promote the precipitation and stabilization of heat-resistant Al3Zr particles and to refine the Fe-rich phases and disperse them on the grain boundaries, thereby improving the heat resistance of the aluminum alloy wire. The prepared aluminum alloy wire has an electrical conductivity of greater than 62% IACS, a strength retention rate of greater than 94% after heating at 230℃ for 1h, and good comprehensive mechanical properties. CN118957364A discloses a high-conductivity heat-resistant aluminum alloy wire and a preparation method thereof. The wire mainly contains Zr 0.03-0.1%, Er 0.05-0.15%, B 0.01-0.04%, Fe 0.05-0.13%, Si 0.03-0.06%, (V+Ti+Cr+Mn) 0.005-0.02%. The prepared wire has an electrical conductivity of ≥61.5% IACS, a tensile strength of ≥160 MPa, and a strength retention rate of greater than 90% after heating at 230℃ for 1h.

[0004] In the above patent documents, the wire disclosed in CN115798778A has a high RE content and a low Fe content, which is not conducive to recycling. The wire disclosed in CN118957364A contains a high content of Er, which is high in cost and not suitable for industrial application. SUMMARY

[0005] In order to overcome at least one technical problem existing in the prior art, one of the purposes of the present application is to provide an aluminum alloy wire material containing a relatively high iron content, Fe, Zr and Al forming a high volume fraction of high temperature phase, improving the heat resistance strength of the aluminum alloy wire material, and introducing Sr and RE rare earth elements to improve the morphology and distribution of the iron-rich phase and improve the plasticity of the aluminum alloy wire material.

[0006] The second purpose of the present application is to provide a preparation method of an aluminum alloy wire material.

[0007] The third purpose of the present application is to provide a product.

[0008] In order to achieve the above-mentioned purposes, the technical solution adopted by the present application is:

[0009] The first aspect of the present application provides an aluminum alloy wire material composed of the following mass percentages of components: Fe 0.5-1.2%, Zr 0.10-0.15%, B 0.01-0.03%, RE 0.01-0.04%, Sr 0.005-0.01%, unavoidable impurities ≤0.15%, and the balance being Al.

[0010] RE is selected from at least one of La and Ce.

[0011] In some embodiments of the present application, the mass percentage of Fe can be selected from any one of 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, 1.1%, 1.2% or a range value formed by any two of them. If the iron content is high, Fe is easy to form coarse iron-rich phase in the aluminum alloy, thereby significantly reducing the plasticity and electrical conductivity of the wire. Therefore, the iron content of the aluminum alloy wire material in the prior art is generally controlled to be below 0.2%. Even if the iron content is less than 0.2%, the prior art also uses rare earth elements to refine the iron-rich phase, thereby reducing the adverse effects of Fe on the performance of the aluminum alloy. However, the aluminum alloy wire material in the present application has a very high iron content, and the iron content ranges from 0.5% to 1.2%. In order to avoid the formation of coarse iron-rich phase, Sr and RE elements are introduced to improve the morphology of the iron-rich phase, so that the aluminum alloy wire material still has excellent mechanical properties and electrical conductivity under high Fe content.

[0012] In addition, the aluminum alloy wire material in the prior art has a low iron content, which cannot use waste aluminum alloy wire material as a raw material, which is not conducive to the recycling of aluminum alloy wires.

[0013] In some embodiments of the present application, the mass percentage of Zr can be selected from any one of 0.10%, 0.11%, 0.12%, 0.13%, 0.14%, 0.15% or a range formed by any two of them. Zr is a common heat-resistant phase, and by high-temperature annealing treatment, a high-density nano-phase can be formed to improve the room temperature and high-temperature strength of the aluminum alloy wire material.

[0014] In some embodiments of the present application, the mass percentage of B can be selected from any one of 0.01%, 0.015%, 0.02%, 0.025%, 0.03% or a range formed by any two of them.

[0015] In some embodiments of the present application, the mass percentage of RE can be selected from any one of 0.01%, 0.015%, 0.02%, 0.025%, 0.03%, 0.035%, 0.04% or a range formed by any two of them. The present application uses less RE and Sr elements to modify up to 0.5-1.2% Fe, improves the morphology of iron-rich phase and refines the iron-rich phase, thereby avoiding the existence of coarse iron-rich phase. In addition, the RE elements in the present application are relatively inexpensive rare earth elements, and the amount used is less, which can significantly reduce the manufacturing cost of aluminum alloy.

[0016] In some embodiments of the present application, the mass percentage of Sr can be selected from any one of 0.005%, 0.006%, 0.007%, 0.008%, 0.009%, 0.01% or a range formed by any two of them.

[0017] In some embodiments of the present application, the RE and Sr are added in the form of Al-Sr-RE intermediate alloy. The Al-Sr-RE intermediate alloy is used as a composite modifier for modification treatment of aluminum alloy. The Al-Sr-RE intermediate alloy is used as a composite modifier to improve the morphology of iron-rich phase. The Al3Fe phase formed by Al and Fe is mainly needle-shaped, and becomes coarse with the increase of Fe content, which has an adverse effect on the plasticity and thermal conductivity of the aluminum alloy wire. The present application utilizes the improvement of the Al-Sr-RE modifier on the iron-rich phase to improve the strength, plasticity and thermal conductivity of the wire. The principle is that the Al-Sr-RE modifier mainly contains Al4(SrRE) and Al3(SrRE) phases which are solid-soluted by Sr and RE, and Al3(SrRE) phase is mainly distributed in the grain boundary of the aluminum alloy wire, which can effectively improve the strength and plasticity of the aluminum alloy wire. In addition, the Al-Sr-RE modifier can also improve the thermal conductivity of the aluminum alloy wire. 11(RESr)3, after adding into the melt, part of Sr, RE elements remain in cluster state. Since Sr, Ce both have very high activity, easily adsorbed on the nucleation particles of iron-rich phase and on the surface thereof, hinder the nucleation and growth of the iron-rich phase, improve the morphology and distribution of the iron-rich phase, and the synergistic adsorption effect of Sr, RE is better. Meanwhile, part of Sr, RE elements are dissolved into the iron-rich phase, change the type and morphology of the iron-rich phase. Under the synergistic effect of Sr, RE, the coarse needle-like iron-rich phase gradually changes to the granular shape with the particle size of 2-6 mu m.

[0018] In some embodiments of the present application, the content of a single impurity element in the inevitable impurities is ≤0.05%.

[0019] The second aspect of the present application provides a preparation method of the aluminum alloy wire material of the first aspect of the present application, comprising the following steps:

[0020] S1: smelting an aluminum-containing raw material, then melt-mixing with an Al-B intermediate alloy, and then melt-mixing with an Al-Sr-RE intermediate alloy to obtain an aluminum alloy melt;

[0021] S2: casting and rolling the aluminum alloy melt to obtain an aluminum alloy rod material;

[0022] S3: annealing and drawing the aluminum alloy rod material to obtain the aluminum alloy wire material. The present application improves the heat resistance, strength and plasticity of the aluminum alloy wire by adding the Al-B intermediate alloy for "boronization" treatment, introducing the Al-Sr-RE intermediate alloy for composite modification treatment, and changing the type, morphology and distribution of the iron-rich phase in the recycled aluminum alloy.

[0023] In some embodiments of the present application, the step S1 is: heating the aluminum-containing raw material to 750-800 DEG C to melt the aluminum-containing raw material, then introducing a mixed gas of a refining agent and an inert gas for refining; then melt-mixing with an Al-B intermediate alloy, transferring the melt after standing, and then melt-mixing with an Al-Sr-RE intermediate alloy to obtain an aluminum alloy melt.

[0024] In some embodiments of the present application, the step S1 is specifically:

[0025] adding the aluminum-containing raw material into a smelting furnace to heat to 750-800 DEG C to melt the aluminum-containing raw material, then introducing a mixed gas of a refining agent and an inert gas for refining;

[0026] then adding an Al-B intermediate alloy for boronization treatment under an electromagnetic stirring system, transferring the melt to a holding furnace after standing for 20-30 min for refining;

[0027] Then, the Al-Sr-RE intermediate alloy is added to the melt under the electromagnetic stirring system to perform modification treatment, and a covering agent is added after the surface scum is removed to obtain the aluminum alloy melt.

[0028] The present application removes transition elements by Al-B intermediate alloy "boronization" treatment. The present application uses discarded aluminum alloy wires and other aluminum-containing waste materials as raw materials to prepare recycled aluminum alloys, which inevitably introduce V and Ti elements. Since the solubility of transition elements in aluminum alloys is large, and the element radius difference is large, it is easy to cause lattice distortion, which is not conducive to the conductivity of aluminum wire materials. B has high binding force with Ti and V, and the high-temperature particles MB2 formed can be removed by natural sedimentation, where M is Ti or V. In order to improve the removal efficiency, the melt is subjected to standing and heat preservation and liquid transfer treatment to reduce the introduction of MB2 into the next link.

[0029] In some embodiments of the present application, the aluminum-containing raw material is selected from at least one of discarded aluminum alloy wires, discarded pure aluminum materials.

[0030] In some embodiments of the present application, the discarded pure aluminum material is selected from at least one of aluminum ceiling, aerosol can, and aluminum foil.

[0031] The present application uses high-proportion waste aluminum wires, industrial pure aluminum waste and the like as raw materials, and the proportion of waste materials can be up to 90% or more. These raw materials contain a high content of Fe. Since the solubility of Fe in aluminum alloy is extremely low, Fe mainly exists in the form of iron-rich phase, and has little effect on the electrical conductivity of aluminum alloy. By taking advantage of the low solid solubility of Fe and the high heat resistance of iron-rich phase, the increase of Fe content effectively increases the volume fraction of heat-resistant phase in the alloy, and improves the room temperature and high temperature strength of the wire.

[0032] In some embodiments of the present application, the melting step in step S1 includes the steps of melting and refining. The melting is to melt the aluminum-containing raw material at 750-800℃, and the refining step is to refine the melt by using a refining agent to remove impurities in the melt.

[0033] In some embodiments of the present application, the melting temperature in step S1 is 750-800℃; in some embodiments of the present application, the melting temperature in step S1 is any one of 750℃, 760℃, 770℃, 780℃, 790℃, 800℃ or a range value formed by any two of them.

[0034] In some embodiments of the present application, the melting and mixing step in step S1 is carried out by using an electromagnetic stirring device.

[0035] In some embodiments of the present application, the preparation method further comprises a step of adding a covering agent; the step of adding a covering agent is located after step S1 and before step S2.

[0036] In some embodiments of the present application, the step of casting is: after degassing the aluminum alloy melt, filtering, and then pouring into a wheel-type crystallizer for continuous casting.

[0037] In some embodiments of the present application, the drawing speed in step S3 is 8-12 m / s; in some embodiments of the present application, the drawing speed in step S3 is any one of 8 m / s, 8.5 m / s, 9 m / s, 9.5 m / s, 10 m / s, 10.5 m / s, 11 m / s, 11.5 m / s, 12 m / s or a range value formed by any two of them.

[0038] In some embodiments of the present application, the temperature of drawing in step S3 is 20-25℃.

[0039] In some embodiments of the present application, in step S3, the deformation of the drawn aluminum alloy rod material is not less than 80%.

[0040] In some embodiments of the present application, the entry temperature during rolling is 500-520℃; in some embodiments of the present application, the entry temperature during rolling is any one of 500℃, 502℃, 504℃, 506℃, 508℃, 510℃, 512℃, 514℃, 516℃, 518℃, 520℃ or a range value formed by any two of them. The entry temperature refers to the temperature of the casting after casting of the aluminum alloy melt entering the continuous rolling mill.

[0041] In some embodiments of the present application, the temperature during rolling is 300-400℃; in some embodiments of the present application, the temperature during rolling is any one of 300℃, 310℃, 320℃, 330℃, 340℃, 350℃, 360℃, 370℃, 380℃, 390℃, 400℃ or a range value formed by any two of them. The temperature during rolling refers to the temperature of the casting during rolling in the continuous rolling mill.

[0042] In some embodiments of the present application, the exit temperature during rolling is 200-250℃; in some embodiments of the present application, the exit temperature during rolling is any one of 200℃, 210℃, 220℃, 230℃, 240℃, 250℃ or a range value formed by any two of them. The exit temperature refers to the temperature of the aluminum alloy rod material after rolling when it comes out of the continuous rolling mill.

[0043] In some embodiments of the present application, the annealing temperature is 360-400℃; in some embodiments of the present application, the annealing temperature is any one of 360℃, 365℃, 370℃, 375℃, 380℃, 385℃, 390℃, 395℃, 400℃ or a range value formed by any two of them.

[0044] In some embodiments of the present application, the annealing time is 2-4h; in some embodiments of the present application, the annealing time is any one of 2h, 2.2h, 2.4h, 2.6h, 2.8h, 3h, 3.2h, 3.4h, 3.6h, 3.8h, 4h or a range value formed by any two of them.

[0045] In some embodiments of the present application, the annealing times is 1-5 times; in some embodiments of the present application, the annealing times is any one of 1 time, 2 times, 3 times, 4 times, 5 times or a range value formed by any two of them.

[0046] In some embodiments of the present application, the drawing times is 1-5 times; in some embodiments of the present application, the drawing times is any one of 1 time, 2 times, 3 times, 4 times, 5 times or a range value formed by any two of them.

[0047] The third aspect of the present application provides a product comprising the aluminum alloy wire material of the first aspect of the present application, and the product is selected from the group consisting of electric wire and cable or electric power fitting.

[0048] The present application has the beneficial effect that the aluminum alloy wire material in the present application has a high iron content, by introducing a low content of Sr and RE elements, the type, morphology and distribution of iron-rich phase in the aluminum alloy are improved, so that the aluminum alloy wire material has a high room temperature tensile strength, excellent electrical conductivity and good high temperature resistance, specifically: the room temperature tensile strength is 230-250MPa, the electrical conductivity is 61-62%IACS, and the residual strength retention rate is 94-98% after being placed at 230℃ for 1h. BRIEF DESCRIPTION OF DRAWINGS

[0049] Figure 1 The high magnification scanning electron microscope image of the as-cast aluminum alloy in Example 1.

[0050] Figure 2 The energy spectrum and element test diagram of point A in Figure 1

[0051] Figure 3 The energy spectrum and element test diagram of point B in Figure 1

[0052] Figure 4 The energy spectrum and element test diagram of point B in Figure 1 ​​The spectrum and element test map of the center C point. DETAILED DESCRIPTION

[0053] The specific implementation of the present application is further described in detail below in conjunction with the accompanying drawings and examples, but the implementation and protection of the present application are not limited thereto. It should be noted that if the following processes are not specifically described in detail, they can be implemented or understood by those skilled in the art with reference to the prior art. If the reagents or instruments used are not marked with the manufacturer, they are conventional products that can be purchased on the market.

[0054] The total deformation in the following examples = the cross-sectional area of the drawn wire after drawing / the cross-sectional area of the rod material before drawing * 100%.

[0055] Example 1

[0056] The present example provides a high-strength heat-resistant aluminum alloy wire material composed of the following components by mass percentage: Fe 1.2%, Zr 0.15%, B 0.02%, Sr 0.01%, La 0.03%, total amount of unavoidable impurities ≤0.15%, and the balance Al. The content of each impurity element in the unavoidable impurities does not exceed 0.05%.

[0057] The present example also provides a preparation method of the above-mentioned aluminum alloy wire material, comprising the following steps:

[0058] (1) Melting: Remove the outer skin of the waste aluminum alloy wire, then add it to the melting furnace together with waste aluminum materials of industrial pure aluminum, such as pure aluminum ceiling, aerosol cans, aluminum foil, etc., and heat to 800°C.

[0059] (2) Component adjustment: Use high-purity argon (purity ≥99.9%) as a carrier to uniformly blow the commercially available aluminum alloy refining agent into the interior of the melt. After 30 minutes of holding, sample testing is performed to adjust the Zr, Fe and impurity element contents in the melt to the designed components.

[0060] (3) "Boriding" treatment and liquid transfer: Add Al-B intermediate alloy, start the electromagnetic stirring system to promote melt flow, ensure complete dissolution of the Al-B intermediate alloy, and then hold for 30 minutes. After the holding is completed, transfer the liquid to a holding furnace, use high-purity argon as a carrier, and introduce commercially available aluminum alloy refining agents to purify the melt.

[0061] (4) Al-Sr-RE composite modification: Add 0.3% of Al-5Sr-10La composite modifier by mass percentage of the melt, and start the electromagnetic stirring device; after the Al-5Sr-10La composite modifier is dissolved, remove the surface dross, and add an appropriate amount of commercially available covering agent to protect the melt. In the Al-5Sr-10La composite modifier, the mass percentage of Sr is 5%, the mass percentage of La is 10%, and the balance is Al.

[0062] (5) Continuous casting and rolling: the aluminum alloy melt is degassed and filtered on line, and then poured into a wheel type crystallizer to be continuously cast to obtain a cast slab.

[0063] (6) Continuous rolling: the cast slab is transferred to a continuous rolling mill to be continuously rolled at an entry temperature of 520°C, a rolling temperature of 400°C, and an exit temperature of 230°C to obtain an aluminum alloy rod.

[0064] (7) Drawing: the aluminum alloy rod is annealed at 380°C for 4h, cooled to room temperature, and then drawn at a speed of 8m / s using a wire drawing machine; subsequently, multiple annealing and drawing are performed, and the total deformation is 80%, to finally obtain the aluminum alloy conductor material in this example.

[0065] The performance of the aluminum alloy conductor material: room temperature strength 245MPa; electrical conductivity 61.2% IACS; 230°C / 1h residual strength ratio reaches 97%.

[0066] The scanning electron microscope image of the second phase of the as-cast and rolled aluminum alloy in Example 1 is tested by high magnification scanning electron microscopy, as shown in Figure 1 , and then the energy spectrum and composition of points A, B and C in Figure 1 are tested by an energy spectrometer, as shown in Figures 2-4 . As shown in Figures 1-4 , the iron-rich phase in the aluminum alloy conductor material is mainly in the form of particles and fibers, with a particle size of 2-6μm and a fiber length of 2-15μm. The iron-rich phase mainly includes three types, including Al-Fe-RE Figure 1 at point A), Al-Fe Figure 1 at point B) and Al-Fe-Sr-RE-Si phase Figure 1 at point C), wherein Si is an unavoidable impurity element, and RE and Sr exist in the form of solid solution elements in the iron-rich phase, thereby changing the morphology and distribution of the iron-rich phase.

[0067] Example 2

[0068] This example provides a high-strength heat-resistant aluminum alloy conductor material, which is composed of the following components by mass percentage: Fe 0.5%, Zr 0.10%, B 0.01%, Sr 0.005%, Ce 0.01%, total amount of unavoidable impurities ≤0.15%, and the balance being Al. The content of each individual impurity element in the unavoidable impurities does not exceed 0.05%.

[0069] This example also provides a method for preparing an aluminum alloy conductor material, including the following steps:

[0070] (1) Melting: The outer skin of the waste aluminum alloy conductor is removed, and then the waste aluminum material of industrial pure aluminum, such as pure aluminum ceiling, aerosol can, aluminum foil, etc., is added into the melting furnace together with the waste aluminum material, and the temperature is raised to 750°C.

[0071] (2) Component adjustment: The commercially available aluminum alloy refining agent is uniformly blown into the interior of the melt with high-purity nitrogen (purity ≥ 99.9%) as the carrier. After 15 min of heat preservation, the components are tested by sampling, and the contents of Zr, Fe and impurity elements in the melt are adjusted to the designed components.

[0072] (3) "Boriding" treatment and liquid transfer: Al-B intermediate alloy is added, the electromagnetic stirring system is started to promote the flow of the melt, and the Al-B intermediate alloy is completely dissolved, and then heat preservation is carried out for 20 min. After the heat preservation is completed, the liquid is transferred to the holding furnace, and the commercially available aluminum alloy refining agent is blown in with high-purity nitrogen as the carrier to purify the melt.

[0073] (4) Al-Sr-RE composite modification: 0.1% (based on the total mass of the melt) of Al-9Sr-10Ce composite modifier is added, and the electromagnetic stirring device is started; after the Al-9Sr-10Ce composite modifier is dissolved, the surface scum is removed, and an appropriate amount of commercially available aluminum alloy covering agent is scattered to protect the melt. In the Al-9Sr-10Ce composite modifier, the mass percentage of Sr is 9%, the mass percentage of Ce is 10%, and the rest is Al.

[0074] (5) Continuous casting and rolling: The aluminum alloy melt is subjected to on-line degassing and filtration, and is poured into a wheel-type crystallizer for continuous casting to obtain a casting blank.

[0075] (6) Continuous rolling: The casting blank is transferred to a continuous rolling mill for continuous rolling, with an entry temperature of 500°C, a rolling temperature of 300°C, and an exit temperature of 220°C, to obtain an aluminum alloy rod material.

[0076] (7) Drawing: The aluminum alloy rod material is annealed at 400°C for 2 h, cooled to room temperature, and then drawn at a speed of 9 m / s using a wire drawing machine; then multiple annealing and drawing are carried out, with a total deformation of 90%, to finally obtain the aluminum alloy conductor material in this example.

[0077] Performance of the aluminum alloy conductor material: room temperature strength 230 MPa; electrical conductivity 61.8% IACS; 230°C / 1h residual strength ratio 95%.

[0078] Example 3

[0079] The example provides a high-strength heat-resistant aluminum alloy wire material, which is composed of the following components in mass percentage: Fe 0.8%, Zr 0.12%, B 0.03%, Sr 0.008%, Ce 0.012%, La 0.018%, total amount of unavoidable impurities ≤0.15%, and the balance of Al. The content of each impurity element in the unavoidable impurities is not more than 0.05%.

[0080] The example also provides a preparation method of the aluminum alloy wire material, which comprises the following steps:

[0081] (1) Melting: the outer skin of the waste aluminum alloy wire is removed, and then the waste aluminum material of industrial pure aluminum, such as pure aluminum ceiling, aerosol can, aluminum foil, etc., is added into a melting furnace together with the waste aluminum material, and the temperature is raised to 780°C.

[0082] (2) Component adjustment: high-purity nitrogen gas (purity ≥99.9%) is used as a carrier to uniformly blow the commercial aluminum alloy refining agent into the interior of the melt. After 15 min of heat preservation, the components are tested by sampling, and the content of Zr, Fe and impurity elements in the melt is adjusted to the designed components.

[0083] (3) "Boriding" treatment and liquid transfer: Al-B intermediate alloy is added, the electromagnetic stirring system is started to promote the flow of the melt, and the complete dissolution of the Al-B intermediate alloy is ensured, and then the melt is heat preserved for 20 min. After the heat preservation is completed, the melt is transferred to a heat preservation furnace, and the commercial aluminum alloy refining agent is blown into the melt by using high-purity argon gas as a carrier to purify the melt.

[0084] (4) Al-Sr-RE composite modification: 0.3% (based on the total mass of the melt) of Al-5Sr-4Ce-6La composite modifier is added, and the electromagnetic stirring device is started; after the modifier is dissolved, the surface scum is removed, and an appropriate amount of covering agent is scattered to protect the melt. In the Al-5Sr-4Ce-6La composite modifier, the mass percentage of Sr is 5%, the mass percentage of Ce is 4%, the mass percentage of La is 6%, and the balance is Al.

[0085] (5) Continuous casting and rolling: the aluminum alloy melt is subjected to online degassing and filtration, and is poured into a wheel-type crystallizer for continuous casting to obtain a casting blank.

[0086] (6) Continuous rolling: the casting blank is transferred to a continuous rolling mill for continuous rolling, the rolling-in temperature is 510°C, the rolling temperature is 350°C, and the rolling-out temperature is 210°C, to obtain an aluminum alloy rod material.

[0087] (7) Drawing: the aluminum alloy rod material is subjected to annealing treatment at 380°C for 3 h, and after cooling to room temperature, the aluminum alloy rod material is drawn by a drawing machine at a speed of 10 m / s; then multiple annealing treatment and drawing are performed, and the total deformation is 85%, to finally obtain the aluminum alloy wire material in the example.

[0088] Performance of the aluminum alloy wire material: room temperature strength 240 MPa; electrical conductivity 61.4% IACS; 230℃ / 1h residual strength ratio 96%.

[0089] Example 4

[0090] The example provides a high-strength heat-resistant aluminum alloy wire material, which is composed of the following components in mass percentage: Fe 1.0%, Zr 0.13%, B 0.025%, Sr 0.007%, Ce 0.012%, La 0.012%, total amount of unavoidable impurities ≤0.15%, and the balance being Al. The content of each impurity element in the unavoidable impurities does not exceed 0.05%.

[0091] The example also provides a preparation method of the aluminum alloy wire material, which comprises the following steps:

[0092] (1) Melting: the outer skin of the waste aluminum alloy wire is removed, and then the waste aluminum material of industrial pure aluminum, such as pure aluminum ceiling, aerosol can, aluminum foil, etc., is added into a melting furnace together with the waste aluminum material, and the temperature is raised to 770℃.

[0093] (2) Component adjustment: high-purity argon (purity ≥99.9%) is used as a carrier to uniformly blow the commercial aluminum alloy refining agent into the interior of the melt. After 25 min of heat preservation, the components are tested by sampling, and the content of Zr, Fe and impurity elements in the melt is adjusted to the designed components.

[0094] (3) “Boriding” treatment and liquid transfer: Al-B intermediate alloy is added, the electromagnetic stirring system is started to promote the flow of the melt, and the complete dissolution of the Al-B intermediate alloy is ensured, and then the melt is heat preserved for 30 min. After the heat preservation is completed, the melt is transferred to a heat preservation furnace, and commercial refining agent is introduced into the melt as a carrier to purify the melt.

[0095] (4) Al-Sr-RE composite modification: 0.2% (based on the total mass of the melt) of Al-7Sr-6Ce-6La composite modifier is added, and the electromagnetic stirring device is started; after the modifier is dissolved, the surface scum is removed, and 0.02% of covering agent is scattered to protect the melt. In the Al-7Sr-6Ce-6La composite modifier, the mass percentage of Sr is 7%, the mass percentage of Ce is 6%, the mass percentage of La is 6%, and the balance is Al.

[0096] (5) Continuous casting and rolling: the aluminum alloy melt is subjected to online degassing and filtration, and is poured into a wheel-type crystallizer for continuous casting to obtain a cast blank.

[0097] (6) Continuous rolling: the cast blank is transferred to a continuous rolling mill for continuous rolling, the rolling-in temperature is 515℃, the rolling temperature is 370℃, and the rolling-out temperature is 230℃, and an aluminum alloy rod material is obtained.

[0098] (7) Drawing: the aluminum alloy rod was annealed at 360°C for 3.5h, and then cooled to room temperature, and then drawn at a speed of 9m / s by using a wire drawing machine; subsequently, the aluminum alloy rod was annealed and drawn for several times, and the total deformation was 82%, and finally the aluminum alloy wire material in this example was obtained.

[0099] The performance of the aluminum alloy wire material: the room temperature strength was 238MPa; the electrical conductivity was 61.3% IACS; the residual strength ratio at 230°C / 1h was 96%.

[0100] Comparative Example 1

[0101] Compared with Example 1, the Fe content in this example reached 1.5%.

[0102] Comparative Example 2

[0103] Compared with Example 2, no “boronization” treatment was performed in this example, i.e., step (3) in Example 2 was not performed.

[0104] Comparative Example 3

[0105] Compared with Example 3, step (4) in Example 3 was not performed in this example, i.e., no Al-Sr-RE composite modifier was added in this example.

[0106] Comparative Example 4

[0107] Compared with Example 4, the Fe content in this example was reduced to 0.15%.

[0108] Performance test:

[0109] The aluminum alloy wire materials in Examples 1-4 and Comparative Examples 1-4 were sampled respectively, and then their tensile strength, electrical conductivity and residual strength were tested, and the specific test methods were as follows:

[0110] Room temperature tensile strength: tested according to the test method described in HB 5177-1996 Metal Wire Tensile Test Method;

[0111] Elongation: tested according to the test method described in HB 5177-1996 Metal Wire Tensile Test Method;

[0112] Electrical conductivity: tested according to the test method described in GB / T 3048.2-2007 “Electrical Performance Test Methods for Wire and Cable Part 2: Electrical Resistance Test of Metal Materials”;

[0113] Residual strength: the aluminum alloy wire was placed at 230°C for 1h, and then its tensile strength was tested, and compared with its room temperature tensile strength, the residual strength was obtained, i.e., residual strength = 230°C / 1h tensile strength / room temperature tensile strength*100%.

[0114] The performance data of the aluminum alloy wire material measured according to the above test method are shown in Table 1 below:

[0115] Table 1 Performance data of the aluminum alloy wire material

[0116]

[0117] From Table 1, it can be seen that the range of Fe content, whether boronizing treatment and Al-Sr-RE composite modification treatment are performed in the preparation method all significantly affect the performance of the wire, wherein the Fe content and the Al-Sr-RE composite modification treatment affect the strength, plasticity, electrical conductivity and high temperature residual strength ratio of the wire material, and the boronizing treatment mainly affects the electrical conductivity of the wire. With the increase of the Fe content, the room temperature tensile strength and the residual strength ratio of the alloy slightly increase, but the elongation and the electrical conductivity slightly decrease. However, too high Fe content leads to significant decrease of the plasticity and the strength, and too low Fe content leads to decrease of the strength and the residual strength ratio. The Al-Sr-RE composite modification significantly improves the mechanical properties and the electrical conductivity of the wire.

[0118] The above has made a detailed description of the embodiments of the present application, but the present application is not limited to the above embodiments, and various changes can be made within the knowledge range possessed by those skilled in the art without departing from the purpose of the present application. In addition, the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

Claims

1. An aluminum alloy conductor material, characterized in that: It is composed of the following components by mass percentage: Fe 0.5-1.2%, Zr 0.10-0.15%, B 0.01-0.03%, RE 0.01-0.04%, Sr 0.005-0.01%, unavoidable impurities ≤0.15%, and the balance being Al; RE is selected from at least one of La and Ce.

2. The aluminum alloy conductor material according to claim 1, characterized in that: The RE and Sr are added in the form of an Al-Sr-RE master alloy.

3. The aluminum alloy conductor material according to claim 1, characterized in that: Of the unavoidable impurities, the content of a single impurity element is ≤0.05%.

4. The method for preparing the aluminum alloy conductor material according to any one of claims 1 to 3, characterized in that: Includes the following steps: S1: Smelt aluminum-containing raw materials, then melt and mix them with Al-B master alloy, and then melt and mix them with Al-Sr-RE master alloy to obtain aluminum alloy melt; S2: Cast and roll the aluminum alloy melt to obtain aluminum alloy rods; S3: Anneal and draw the aluminum alloy rod to obtain the aluminum alloy wire material.

5. The method for preparing aluminum alloy conductor material according to claim 4, characterized in that: The aluminum-containing raw material is selected from at least one of waste aluminum alloy wires and waste pure aluminum materials.

6. The method for preparing aluminum alloy conductor material according to claim 5, characterized in that: The waste pure aluminum material is selected from at least one of aluminum ceilings, aerosol cans, and aluminum foil.

7. The method for preparing aluminum alloy conductor material according to claim 4, characterized in that: In step S1, the melting temperature is 750–800°C; And / or, the drawing speed in step S3 is 8 to 12 m / s.

8. The method for preparing aluminum alloy conductor material according to claim 4, characterized in that: In step S2, rolling has at least one of the following characteristics: (a1) The entry temperature during rolling is 500-520℃; (a2) The rolling temperature is 300–400°C; (a3) The exit temperature during rolling is 200-250℃.

9. The method for preparing aluminum alloy conductor material according to claim 4, characterized in that: The annealing has at least one of the following characteristics: (b1) The annealing temperature is 360–400°C; (b2) The annealing time is 2 to 4 hours; (b3) The number of annealing cycles is 1 to 5.

10. A product, characterized in that: The product includes the aluminum alloy conductor material as described in any one of claims 1 to 3, wherein the product is selected from wires and cables or power fittings.

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