A rare earth modified high-strength torsion-resistant aluminum alloy cable and a method for manufacturing the same

Abstract

The application relates to the technical field of aluminum alloy cables, and provides a rare earth modified high-strength torsion-resistant aluminum alloy cable and a preparation method thereof, which is composed of the following components in percentage by mass: Si 0.31%-0.34%; Fe 0.33%-0.38%; Mg / Si, rare earth Re, Mn / Fe, Ni / Fe are controlled, and Cu, Zr, Nb and B are optimized; and the balance is aluminum. The aluminum alloy wire has high tensile strength, high elongation and high conductivity, no cracks and no torsion under the condition of 1440 DEG torsion experiment at room temperature, and the wire breaking rate is less than 0.9% under the condition of 1440 DEG torsion experiment at 45 DEG C, that is, the torsion-resistant aluminum alloy cable with better comprehensive performance is obtained.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of aluminum alloy cables, in particular to a rare earth modified high-strength torsion-resistant aluminum alloy cable and a preparation method thereof. BACKGROUND

[0002] Wind power naturally has irreplaceable characteristics and scalability, and as an important green energy, it is one of the main core in renewable energy. The installed capacity of wind power will be greatly improved, China has become the largest and fastest growing market for wind power generation in the world, and the installed capacity of wind power will reach more than 300GW after 2022. The large-scale and on-grid era of wind power has arrived, and reducing the cost of infrastructure construction such as tower drums has become the key to promoting industry development. As an important component, the cost optimization of cables is of great significance.

[0003] Torsion-resistant wind power cables are widely installed in complex environments such as high temperature, high humidity, salt spray, and large temperature difference, and the cable is frequently twisted during operation. Therefore, the cable is required to have high temperature resistance, corrosion resistance, and torsion resistance, and to ensure that the cable can pass the normal temperature 10000 cycle or more torsion test (clockwise twist 1440°, then recover to the initial state, then counterclockwise twist the same angle, then recover to the initial state, and so on as a cycle) and 2000 cycle or 5000 cycle low temperature torsion test. With the arrival of the large-scale and on-grid era of wind power, it has become a trend to replace copper core cables with aluminum alloy cables in the fixed section of the tower drum. However, the twisted cable section still uses copper core cables. Torsion-resistant cables are one of the important components, and currently the conductors of torsion-resistant cables are mainly copper, but there are problems such as copper resource scarcity, high and volatile international copper prices, and uncontrollable costs. Copper has a high density (8.96 g / cm³), and the self-weight of the vertically installed cable in the tower drum is extremely large, which not only increases the load of the tower drum, but also seriously deteriorates the torsion resistance of the cable. The tensile strength and elongation are still insufficient for the harsh working conditions of wind power frequent twisting.

[0004] Aluminum resources are abundant, low in cost, and small in density (2.7 g / cm³), and have excellent electrical conductivity, which can achieve the dual goals of cost reduction (about 30%-50%) and weight reduction (about 60%). Using aluminum alloy conductors to replace copper conductors to make torsion-resistant cables has a good application prospect. However, existing aluminum alloy conductors have low tensile strength and cannot well balance tensile strength and elongation performance, such as the existing aluminum alloy products with a tensile strength greater than 150Mpa, the elongation rate sharply decreases to 1%-2% (brittle state), and the high temperature stability is insufficient, which is not conducive to the torsion resistance of the cable, and cannot meet the requirements of the cable having high temperature resistance, corrosion resistance, and torsion resistance when the cable is frequently twisted in complex environments such as high temperature, high humidity, salt spray, and large temperature difference, limiting the application prospect of aluminum alloy cables as torsion-resistant cables.

[0005] In the prior art, in order to adapt to the application of aluminum alloy cable as a torsion-resistant cable, a soft aluminum alloy wire core for a wind power tower torsion conductor and a preparation method thereof are provided, the aluminum alloy conductor can be used in a torsion occasion, but it adopts graphene sodium magnesium aluminum powder, but the cost is high, the processing difficulty is great, the composite powder is easy to agglomerate, the toughness cannot meet the requirements when the strength of the conductor is improved, repeated bending is easy to break, is greatly affected by heat, and has obvious problems such as sharp decrease in strength at high temperature.

[0006] In the prior art, a torsion-resistant aluminum alloy wind power cable is provided, and the main aluminum alloy formula includes the following components in percentage by mass: Si 0.4%-0.6%, Fe 0.1%-0.3%, Cu 0.02%-0.05%, Mn 0.01%-0.02%, Mg 0.35%-0.5%, Cr 0.01%-0.02%, Zn≤0.10%, B 0.01%-0.05%, Li 0.001%-0.005%, Zr 0.003%-0.01%, Sn 0.001%-0.005%, Sc 0.016%-0.02%; the component design is unreasonable, for example, the Si content is too high, which affects the bending fatigue performance, electrical performance, and is not conducive to the improvement of torsion performance; the tensile strength of the outermost aluminum alloy monofilament is 115-152 MPa, and the elongation at break is ≥15%; the overall tensile strength and elongation at break fluctuate greatly, and the problems of insufficient conductivity and high-temperature resistance are not considered.

[0007] In the prior art, a high-strength aluminum alloy five-type conductor for a wind power torsion-resistant cable and a preparation method thereof are provided; Si: 0.35 parts-0.8 parts, Fe: 0.1 parts-0.3 parts, Mg: 0.35 parts-0.8 parts, B: 0.008 parts-0.04 parts, Ni: 0.006 parts-0.03 parts, Ce: 0.006 parts-0.02 parts, La: 0.006 parts-0.02 parts, Sc: 0.006 parts-0.015 parts. The tensile strength of the monofilament is ≥150 Mpa; the elongation is ≥8%; the electrical conductivity is ≥50%IACS. The tensile strength is improved, but the elongation is affected, the performance is insufficient, the electrical conductivity needs to be improved, and the high-temperature resistance is not considered.

[0008] As known from the above, when the aluminum alloy cable is applied to a torsion-resistant cable, there are problems such as unmatched tensile strength, high-temperature resistance, high-low temperature torsion performance, elongation, electrical conductivity, and unreasonable component design. Therefore, the present application provides a rare earth modified high-strength torsion-resistant aluminum alloy cable and a preparation method thereof, which are used to prepare a torsion-resistant aluminum alloy cable with better comprehensive performance. SUMMARY

[0009] To overcome the deficiencies of the prior art, the application provides a rare earth modified high-strength torsion-resistant aluminum alloy cable and a preparation method thereof, the tensile strength of which is greater than or equal to 180 MPa, the elongation is greater than or equal to 19%, the electrical conductivity is greater than or equal to 63% IACS, and there is no crack and distortion in the 1440° torsion test under normal temperature for 10000 cycles, and the wire breaking rate is less than 0.9% in the 1440° torsion test under 45°C for 15000 cycles, so that a torsion-resistant aluminum alloy cable with better comprehensive performance is obtained.

[0010] Embodiments of the application are implemented as follows:

[0011] The examples of the application provide a rare earth modified high-strength torsion-resistant aluminum alloy cable, which is composed of the following components in mass percentage:

[0012] Si 0.31%-0.34%;

[0013] Fe 0.33%-0.38%;

[0014] Mg / Si=0.65-0.91;

[0015] rare earth , k=0.19-0.28;

[0016] Mn / Fe for 0.21-0.26;

[0017] Ni / Fe for 0.12-0.18;

[0018] Cu 0.06%-0.09%;

[0019] Zr 0.06%-0.09%;

[0020] Nb 0.08%-0.13%;

[0021] B 0.002%-0.005%;

[0022] the balance is aluminum.

[0023] Optionally, 0.12%≤Mn+Ni≤0.14%.

[0024] Optionally, 0.15%≤Zr+Nb≤0.17%.

[0025] Optionally, the rare earth Re includes La, Ce, and Er; wherein Er accounts for 20-30% of the total mass of Zr+Nb.

[0026] Optionally, the tensile strength is ≥180Mpa; the elongation is ≥19%; the electrical conductivity is ≥63%IACS; there is no crack and distortion in 1440° torsion test under normal temperature for 10000 cycles; the yarn breakage rate is less than 0.9% in 1440° torsion test under 45℃ for 15000 cycles.

[0027] Optionally, the precipitated particles on the surface of the aluminum alloy wire are detected by scanning electron microscopy, the area rate of the particles is ; the number of the precipitated particles is 0.007-0.15 per μm 2 , and there is no bubble on the surface of the aluminum alloy wire.

[0028] In another aspect, a preparation method of a rare earth modified high-strength torsion-resistant aluminum alloy cable is provided, which is used to prepare the aforementioned rare earth modified high-strength torsion-resistant aluminum alloy cable, and the specific method comprises the following steps:

[0029] (1) selecting industrial pure aluminum ingot, Si source, Fe source, Mg source, rare earth source, Mn source, Ni source, Cu source, Zr source, Nb source, and B source as raw materials, and performing batching according to the designed composition;

[0030] (2) heating and melting the industrial pure aluminum at 710-750℃, adding the above-mentioned raw materials, and fully stirring the molten aluminum alloy after melting to make the composition of the molten aluminum alloy uniform;

[0031] (3) performing in-furnace refining, degassing, and impurity removal treatment on the molten aluminum alloy, stirring at high temperature of 730-740℃ using large argon flow, the argon flow being 33-38L / min; stirring at low temperature of 705-715℃ using small argon flow, the argon flow being 18-21L / min to facilitate deep hydrogen removal; and then standing for 35-55min to remove slag;

[0032] (4) continuous casting and rolling, the entry temperature being 560-570℃, and the aluminum alloy round rod being continuously cast and rolled to 9-10mm;

[0033] (5) performing solid solution and aging treatment on the aluminum alloy round rod;

[0034] (6) drawing the aluminum alloy round rod into an aluminum alloy wire, and obtaining the rare earth modified high-strength torsion-resistant aluminum alloy cable through annealing, the wire diameter being 0.9-1.5mm.

[0035] Optionally, in step (3), ultrasonic treatment is performed before the continuous casting and rolling, the ultrasonic power being 10-13Kw, and the frequency being 2-3KHz.

[0036] Optionally, in step (5), the aluminum alloy round rod is solid-solved at low temperature of 540-560℃ for 40-55h, and then aged at low temperature of 310-330℃ for 67-77h.

[0037] Optionally, in step (6), annealing at 170-190°C.

[0038] The beneficial effects include:

[0039] 1、The present application adopts high Fe, high Si, low Mg / Si, and considers the solid solution strengthening of Mg and Si components, and strictly controls the addition amount of rare earth according to part of Si and high iron content, so as to strictly control the composition design of rare earth refining strengthening, so as to realize that the tensile strength is greater than or equal to 180Mpa; the elongation is greater than or equal to 19%; the electrical conductivity is greater than or equal to 63%IACS, the 1440° torsion experiment under the condition of 10000 cycles at room temperature has no crack and distortion, the wire breaking rate is less than 0.9% in the 1440° torsion experiment under the condition of 15000 cycles at 45°C, and the better comprehensive performance of the torsion-resistant aluminum alloy cable is obtained.

[0040] 2、By adding Mn, the content of Mn is determined based on the content of Fe, which is beneficial to compete with Fe to a certain extent to generate more beneficial precipitated phase, thereby reducing the potential adverse effects of high Fe and Si content, especially cutting off the possibility of Fe excess, reducing the opportunity of excess free Fe elements forming harmful blocky β-AlFeSi phase, thereby achieving the purpose of improving tensile strength, heat resistance and torsion resistance. By limiting Mn / Fe, the competitive relationship between Mn and Fe is actually considered. Controlling Ni / Fe, by adding an appropriate amount of Fe, the main purpose is to improve the effect of adding nickel to form AlFeNi composite high-temperature strengthening phase, and avoid excessive addition to form AlNi composite phase (with deteriorated performance); Ni / Fe is too high to form AlNi composite phase, and Ni / Fe is too low to form AlFeNi composite high-temperature strengthening phase, which is not conducive to improving heat resistance, especially high-temperature torsion resistance. Copper is a basic strengthening element in aluminum alloy, and copper (Cu) is dissolved in aluminum alloy to form θ (Al2Cu) phase, and θ phase has the effects of solid solution strengthening and dispersion strengthening, which can improve the tensile strength and yield strength of the conductor and the heat resistance, and is beneficial to improve the high-temperature torsion resistance. By adding higher amounts of Zr and Nb elements in high-tensile-strength torsion-resistant conductors, high-tensile-strength and heat-resistant and torsion-resistant properties are obtained.

[0041] 3. Stirring at high temperature of 730-740℃ with large argon flow, argon flow is 33-38L / min to facilitate the fast floating of large inclusions, slag removal, impurity removal, and preliminary degassing; stirring at low temperature of 705-715℃ with small argon flow, argon flow is 18-21L / min to facilitate the deep hydrogen removal and removal of tiny inclusions, and reducing temperature is conducive to reducing oxidation and other new inclusions, small flow produces smaller bubbles with larger surface area, which is conducive to more efficiently adsorbing residual hydrogen atoms and micron or even submicron tiny inclusions in the melt and taking them to the liquid surface; thereby facilitating the increase of the residual amount of melt gas, especially hydrogen, and facilitating the purification of the melt, reducing the solidification and precipitation core in the later stage, which is conducive to reducing the bubbles on the surface of the wire, refining the grains, refining the precipitated phase, and more conducive to improving the tensile strength and torsion resistance and other properties.

[0042] 4. More tiny precipitated particle phases are generated on the surface of the aluminum alloy wire, which reduces the possibility of crack generation and is more conducive to improving the tensile strength and torsion resistance and other properties. DETAILED DESCRIPTION

[0043] The technical solutions of the present application will be described below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0044] Those skilled in the art can understand that, unless otherwise defined, all the terms (including technical terms and scientific terms) used herein have the same meaning as the general understanding of those skilled in the art to which the present application belongs. It should also be understood that terms such as those defined in general dictionaries should be understood as having meanings consistent with those in the prior art, and unless specifically defined as here, should not be interpreted as idealized or overly formal meanings.

[0045] Those skilled in the art can understand that, unless otherwise stated, the singular form "a", "an", "said" and "the" used herein can also include the plural form. It should be further understood that the use of the word "comprise" in the specification of the present application means that the features, integers, steps, operations, elements and / or components exist, but do not exclude the existence or addition of one or more other features, integers, steps, operations, elements, components and / or their combinations. The phrase "and / or" used herein includes all or any single unit and all combinations of the associated listed items. The raw materials used below are all from commercially available products, unless otherwise specified. The performance tests can be referred to the national standards or industry standards, unless otherwise specified.

[0046] For the aluminum alloy cable applied to the torsion-resistant cable, there are problems such as that tensile strength, high-temperature resistance, high-low temperature torsion performance, elongation, electrical conductivity, and unreasonable component design cannot be matched. Therefore, the embodiment of the present application provides a rare earth modified high-strength torsion-resistant aluminum alloy cable and a preparation method thereof.

[0047] The features and performances of the present application are further described in detail in combination with the following embodiments:

[0048] The embodiment of the present application provides a rare earth modified high-strength torsion-resistant aluminum alloy cable, which is composed of the following components with mass percentage:

[0049] Si 0.31%-0.34%;

[0050] Fe 0.33%-0.38%;

[0051] Mg / Si=0.65-0.91;

[0052] Rare earth , k=0.19-0.28;

[0053] Mn / Fe for 0.21-0.26;

[0054] Ni / Fe for 0.12-0.18;

[0055] Cu 0.06%-0.09%;

[0056] Zr 0.06%-0.09%;

[0057] Nb 0.08%-0.13%;

[0058] B 0.002%-0.005%;

[0059] The balance is aluminum.

[0060] Optionally: 0.12%≤Mn+Ni≤0.14%;

[0061] Optionally, 0.15%≤Zr+Nb≤0.17%;

[0062] Optionally, the rare earth Re includes lanthanum (La), cerium (Ce), and erbium (Er); wherein the erbium (Er) accounts for 20-30% of the total mass of Zr+Nb.

[0063] It can be understood that the aluminum alloy has many added components, and each element has different effects. Although the individual effects of each element are clear, the relationship between them is unknown. To avoid the effects of different elements, the present application does not add or add less of the elements not involved, such as not containing Cr, Zn, Li, Sn, Sc, Ca, Be, Co, Mo, Ga, V, K, Na, Sr, Ti, Rb, Pd, Ag and other elements. This is conducive to reducing costs while avoiding the unpredictable effects of adding the above elements on performance.

[0064] The present application adopts high Fe, high Si, low Mg / Si, and considers the solid solution strengthening of Mg and Si components. After that, the amount of rare earth is strictly controlled according to the high iron content and part of Si, so as to strictly control the composition design of rare earth refining strengthening, so as to realize the tensile strength ≥180Mpa; the elongation ≥19%; the conductivity ≥63%IACS, 10000 cycles of 1440° torsion test under normal temperature condition without crack and torsion, the wire breaking rate is less than 0.9% in 15000 cycles of 1440° torsion test under 45℃ condition, and the aluminum alloy cable with better comprehensive performance and better torsion resistance is obtained.

[0065] Among them, the addition of high iron content can form a large number of Al3Fe and Al6Fe precipitated phases with submicron fine and regular Al3Fe and Al6Fe in the aluminum, which can make the alloy obtain higher strength, improve the heat resistance, improve the single wire elongation, and improve the torsion resistance under high strength condition. However, the content of Fe cannot be too high. If it exceeds the above components, the electrical performance of the wire will be significantly reduced. The content of Fe cannot be lower than the above range. If it is lower than the above range, it is not conducive to improving the strength of the wire, and lower than the content is not conducive to the action with Si, rare earth Re and other elements to produce composite strengthening phase, which cannot effectively improve the performance of the wire. Fe can be selected as 0.33%, 0.34%, 0.35%, 0.36%, 0.37%, 0.38% and the like.

[0066] The addition of high silicon content, the action of Mg and Si, forms Mg2Si strengthening phase, enhances the tensile strength of aluminum alloy wire, especially the tensile strength at high temperature, and is conducive to improving the torsion resistance of the wire at high temperature. At the same time, high content design has the effects of improving corrosion resistance and improving the elongation of aluminum alloy. However, if the Si content is higher than the above range, the electrical performance and fatigue bending performance will be reduced, which will reduce the tensile performance and affect the improvement of the torsion resistance. If the Si content is lower than the above range, it is not conducive to realizing high tensile strength and improving the torsion resistance of the wire at high temperature. Therefore, through the design of high iron and high silicon, Fe, Si and Al form AlFeSi phase (such as β-Al5FeSi), which can greatly improve the tensile strength of the wire, especially the tensile strength at high temperature, and is conducive to improving the torsion resistance of the wire at high temperature.

[0067] The addition of magnesium can produce more lattice distortion due to the larger atomic radius of magnesium element, realize solid solution hardening, and the uniform distribution of fine dispersed particles in the wire crystal, which is beneficial to obtain fine and uniform crystal structure and fine and uniform dispersed particles precipitated inside or on the boundary of the crystal structure. Meanwhile, magnesium can also improve the corrosion resistance and heat resistance of aluminum alloy, and the improvement of corrosion resistance is more conducive to reducing the defects on the surface of the wire, especially the formation of crack defects (cracks will be greatly enlarged in the twisting process, leading to reduced twisting performance), thereby improving the torsion resistance. However, due to the excessive addition of magnesium, the resistance may increase, the heat resistance may decrease, and excessive Mg2Si strengthening phase may be formed with Si, which has high brittleness, leading to reduced elongation, and the performance may be easily deteriorated during heat treatment. For example, during the aging treatment process, Mg and Si atoms are easily precipitated at the grain boundary, forming a precipitate free zone (PFZ) and coarse grain boundary Mg2Si phase, which becomes a natural source of cracks, and has high thermal instability, which leads to a serious decrease in torsion resistance under repeated tension and torsion. Therefore, Mg / Si = 0.65-0.91 (which can be selected as 0.65, 0.68, 0.71, 0.74, 0.76, 0.79, 0.83, 0.85, 0.87, 0.88, 0.89, 0.91, etc.), low magnesium design is adopted, and the content of Si is strictly limited to have a lower ratio, so that silicon is excessive, which is beneficial to the complex effect of silicon, aluminum and iron, and the complex effect of other elements such as rare earth elements, so that the generation of Mg2Si strengthening phase is more controllable, and the excessive generation is avoided, which is beneficial to the role of magnesium in improving the corrosion resistance and heat resistance of aluminum alloy and the torsion resistance.

[0068] The solid solubility of rare earth in aluminum is very low. When a small amount of additive is used, that is, the amount of rare earth exceeds the limit of its solid solubility in the aluminum matrix, the excess rare earth will combine with other elements (such as Fe, Si) or itself to form rich rare earth intermetallic compounds; for example: part of Fe in the alloy is precipitated in the form of Al3Fe and Al6Fe, part of Fe is precipitated in the form of AlFeRE compound with RE, and part of Fe is precipitated in the form of AlSiFeRE compound with RE; The previous aluminum alloy system contains Mg and silicon, mainly using Mg2Si strengthening phase to improve performance, but it has the adverse effects described above. When the low-magnesium design of Mg / Si = 0.65-0.91 is used, the high-iron and high-silicon design can promote Fe to form AlFeSi phase (such as β-Al5FeSi) with Si and Al, which can greatly improve the tensile strength of the conductor, especially at high temperature, and is beneficial to the improvement of the conductor's torsion resistance at high temperature. However, the AlFeSi phase formed by Fe, Si and Al is prone to form flaky or needle-shaped, which is a brittle phase and is not conducive to performance optimization; by adding rare earth, rare earth elements (such as Ce, La, Er, etc.) will react strongly with Fe, Si and other elements, that is, the flaky / needle-shaped β-Al5FeSi phase is modified into fine, spherical (Al, Fe, Si, RE) multi-component phase. The fine, hard and uniformly distributed spherical phase particles become a strong obstacle to dislocation movement, greatly improving the tensile strength of the alloy. In addition, it has a strong grain refinement effect, improves the uniformity of precipitated phase distribution, and the fine, hard and uniformly distributed spherical phase particles have extremely high thermal stability, greatly eliminating stress concentration effect, making it difficult for cracks to occur, and greatly improving the torsion resistance, especially at high temperature. That is, by using the low-magnesium, high-iron and high-silicon design of Mg / Si = 0.65-0.91, by adding an appropriate amount of rare earth, the proportion of fine, spherical (Al, Fe, Si, RE) multi-component phase is increased while the Mg2Si strengthening phase is generated, which is beneficial to improving the tensile strength of the conductor, especially at high temperature, and is beneficial to improving the conductor's torsion resistance at high temperature.

[0069] Due to the very low solid solubility of rare earth in aluminum, excess rare earth can cause deterioration of the performance of the conductor, for example, excess addition and combination with other elements (such as Fe, Si) or itself to form more coarse, massive, rich rare earth intermetallic compounds, such as Al4Ce, Al8Cu4Ce, which can become a crack source and greatly affect the torsion resistance. Rare earth , k = 0.19-0.28, research has found that the solid solution strengthening of Mg and Si components consumes part of Si, The introduction of Mg and Si is actually to consider the effect of solid solution strengthening of Mg and Si components on the combination of rare earth with Fe and Si (in fact, part of Si interacts with rare earth, and the corresponding proportion can be obtained through a large amount of production data summary), by correlating the addition of rare earth component with part of Si and high iron content, the amount of rare earth added is strictly controlled, and then the proportion of rare earth and Al, Fe and Si forming precipitated phase is controlled, so as to strictly control the effect of rare earth refining and strengthening, and add appropriate amount of rare earth, at the same time of generating Mg2Si strengthening phase, generate appropriate proportion of fine and spherical (Al, Fe, Si, RE) multi-component phase, at the same time, the affinity of rare earth elements with hydrogen and other elements is greater than that of aluminum, by strictly controlling the addition of rare earth elements, it is beneficial to reduce the bubble residue on the surface of the aluminum alloy wire after preparation (mainly caused by hydrogen and other gases, bubble residue will become the starting point of subsequent crack, affecting the improvement of torsion resistance), thereby improving the tensile strength of the wire, especially the tensile strength at high temperature, and facilitating the improvement of the torsion resistance of the wire at high temperature.

[0070] The addition of manganese (Mn) can improve the corrosion resistance by combining with aluminum to obtain MnAl4 with approximately the same potential as pure aluminum; as a high-temperature strengthening phase, manganese can improve the solid solution strengthening, supplementary strengthening (by increasing the recrystallization temperature, forming MnAl6 compound dispersed particles to refine the recrystallized grains, etc.) and heat resistance of the aluminum alloy. In addition, the addition of Mn can reduce the adverse effects of Fe and Si, the main reason being that Mn can promote the formation of α-Al(FeMn)Si phase to be finer and spherical, greatly eliminating crack sources, i.e. under high Fe and Si conditions, by adding Mn, the content of Fe is determined to a certain extent, which is beneficial to compete with Fe to some extent, generate more beneficial precipitated phase, thereby reducing the potential adverse effects of high Fe and Si content, especially cutting off the possibility of excess Fe, reducing the opportunity for excess free Fe elements to form harmful blocky β-AlFeSi phase, thereby achieving the purpose of improving tensile strength, heat resistance and torsion resistance. Mn / Fe is 0.21-0.26, optionally 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, etc.; by limiting Mn / Fe, the competitive relationship between Mn and Fe is actually considered, the addition ratio of Mn relative to the content of Fe cannot be too high, excessive Mn addition will replace the role of Fe, excessive Mn addition will lead to larger precipitated phase (e.g. coarse composite phase with high Mn and Fe content, reducing the beneficial AlFeSi, AlFeMnSi composite phase precipitation), Mn is prone to segregation, affecting the uniformity of the composition and deteriorating the tensile strength and torsion resistance; the addition ratio of Mn relative to the content of Fe cannot be too low, which is not conducive to reducing the adverse effects of Fe and Si and improving performance.

[0071] The addition of nickel is conducive to the formation of AlFeNi composite high-temperature strengthening phase, which is distributed in the matrix grain boundary in the form of fine and dispersed phase, has high-temperature thermal stability, can strongly pin the grain boundary and dislocation, that is, the proportion of heat-resistant high-temperature phase in the fine and dispersed precipitated phase is increased, the stability of the aluminum alloy crystal structure is enhanced, thereby the heat resistance, especially the high-temperature torsion resistance, is improved; Ni / Fe is 0.12-0.18, which can be 0.12, 0.12, 0.14, 0.15, 0.16, 0.17, 0.18, etc. By adding an appropriate amount of Fe, the main purpose is to enhance the effect of the addition of nickel to form AlFeNi composite high-temperature strengthening phase, and to avoid excessive addition to form AlNi composite phase (which has a deteriorated performance); if Ni / Fe is too high, AlNi composite phase is formed, and if Ni / Fe is too low, AlFeNi composite high-temperature strengthening phase is insufficient, which is not conducive to improving the heat resistance, especially the high-temperature torsion resistance.

[0072] Alternatively, manganese and nickel are added as elements that have a significant effect on Fe, and by further limiting 0.12%≤Mn+Ni≤0.14%, the total amount of manganese and nickel is limited to avoid excessive addition, thereby avoiding the influence of the addition of manganese and nickel on the beneficial effect of high Fe and Si.

[0073] Copper is a basic strengthening element in aluminum alloy. In the aluminum alloy, copper (Cu) is solid-solved to form θ (Al2Cu) phase, and the θ phase has the effects of solid-solution strengthening and dispersion strengthening, which can improve the tensile strength and yield strength of the conductor and the heat resistance, thereby improving the high-temperature torsion resistance. Cu is 0.06%-0.09%, which can be 0.06%, 0.07%, 0.08%, 0.09%, etc. If it is higher than the above range, it will affect the realization of high electrical conductivity; if it is lower than the above range, it is not conducive to improving the tensile strength and torsion resistance.

[0074] The addition of Zr in the aluminum alloy has a relatively obvious improvement in the tensile strength, and improves the heat resistance of the aluminum alloy. The atomic radius of zirconium is larger than that of aluminum, and the diffusion activation energy of zirconium in aluminum is high, which is easy to form stable nanoscale Al3Zr precipitated phase, pin the dislocation and grain boundary to improve the tensile strength, effectively pin the dislocation and grain boundary at high temperature, hinder the deformation and intracrystalline and grain boundary slip, and the precipitated phase is more stable during heat treatment and the like, thereby improving the heat resistance. By adding a higher amount of Zr element in the high-tensile-strength torsion-resistant conductor, it is beneficial to obtain high tensile strength and heat-resistant and torsion-resistant performance. Zr is 0.06%-0.09%, which can be 0.06%, 0.07%, 0.08%, 0.09%; if it is lower than the above range, it is not conducive to improving the nanoscale precipitated phase and improving the heat resistance; if it is higher than the above range, excessive Zr will cause brittle Zr-containing precipitated phase to be generated, which is not conducive to improving the tensile strength and torsion resistance.

[0075] Nb element can precipitate nanoscale high-temperature dispersed precipitates such as AlNb3, AlNb, Al3Nb, etc., which have high thermal stability, pin dislocations and grain boundaries to improve tensile strength, can effectively pin dislocations and grain boundaries at high temperature, hinder deformation and intragranular and grain boundary slip, and the precipitates are more stable during heat treatment and the like and are not easy to coarsen, thereby improving heat resistance, and by adding a higher amount of Zr element in the high-tensile-strength torsion-resistant conductor wire, high tensile strength and heat resistance and torsion resistance can be obtained. Nb0.08%-0.13%; it can be 0.08%, 0.09%, 0.10%, 0.11%, 0.12%, 0.13%, etc.; below the above range, it is not conducive to improving nanoscale precipitates and improving heat resistance, and above the above range, Nb excess will lead to the generation of brittle Nb-containing precipitates, which are not conducive to improving tensile strength and torsion resistance.

[0076] Optionally, Zr and Nb are particles that improve heat resistance, and can be selected as: 0.15%≤Zr+Nb≤0.17%; the combined amount of the two needs to be controlled to avoid excessive addition of the two, which will cause the aggregation and growth of nanoscale precipitates, which is not conducive to improving tensile strength and torsion resistance.

[0077] Optionally, rare earth Re includes lanthanum (La), cerium (Ce), and erbium (Er); wherein erbium (Er) accounts for 20-30% of the total mass of Zr+Nb. Er is a common element added to improve thermal conductivity in heat-resistant conductive alloys, but how to appropriately add and optimize performance in high-strength torsion-resistant aluminum alloys has not been reported. The rare earth element Er has the effects of promoting the precipitation of solute atoms, reducing lattice distortion, and improving electrical conductivity, and the combined effect of Er, Nb, and Zr can promote the formation of Al3(Nb, Zr) high-thermal-stability particles and the formation of appropriately refined nanoscale precipitates. Heat resistance is not the first major consideration in high-strength torsion-resistant aluminum alloys, and then the need for torsion resistance improvement, during the twisting process of the conductor wire, actually increases the internal particle friction heat and local torsion heat, etc. By adding relatively low Er in heat-resistant aluminum alloys, Al3(Nb, Zr) high-thermal-stability particles are precipitated in a suitable particle size and quantity, which effectively solves the problem of improving the torsion resistance of high-strength torsion-resistant aluminum alloys, and also helps to improve the electrical conductivity. By controlling the content of erbium (Er), the remaining components are mainly lanthanum (La) and cerium (Ce). The above elements are relatively easy to obtain, low in cost, and easy to reduce alloy cost. At the same time, the deep modification effect of La and Ce ensures that all coarse and sharp brittle phases (especially β-AlFeSi) are completely eliminated, thereby eliminating the initiation of fatigue cracks from the root cause, and also has better dehydrogenation effect, which is conducive to controlling the grain size in a suitable micron particle size and eliminating dendritic structure, thereby improving the tensile strength, elongation, electrical conductivity, and torsion resistance.

[0078] B is added to purify the melt, especially to purify the influence of non-added components in Ti, V, Cr and other raw materials, to further reduce the content to trace amount (may be referred to as not added or not containing the corresponding component), so as to improve the performance, because Ti, V, Cr and other non-active addition, thus B adopts the addition amount of 0.002%-0.005% with extremely low content.

[0079] In another aspect, a preparation method of a rare earth modified high-strength torsion-resistant aluminum alloy cable is provided, comprising the following steps:

[0080] (1) Selecting industrial pure aluminum ingot, Si source, Fe source, Mg source, rare earth source, Mn source, Ni source, Cu source, Zr source, Nb source, B source as raw materials, and according to the design composition for batching; Si source, Fe source, Mg source, rare earth source, Mn source, Ni source, Cu source, Zr source, Nb source, B source are not limited, and the existing commonly used raw materials are selected and adjusted to meet the cost requirements.

[0081] (2) The industrial pure aluminum is heated and melted at 710-750℃, the above raw materials are added, and after melting, the aluminum alloy liquid is fully stirred to make the composition uniform;

[0082] (3) The aluminum alloy liquid is treated by in-furnace refining, degassing and impurity removal, high temperature stirring is carried out at 730-740℃ with large argon flow rate, the argon flow rate is 33-38L / min to facilitate the rapid floating of large inclusions, and the slag, impurities and primary gas are removed; low temperature stirring is carried out at 705-715℃ with small argon flow rate, the argon flow rate is 18-21L / min to facilitate deep hydrogen removal and removal of small inclusions, and the temperature is lowered to reduce oxidation and other new inclusions, small flow generates smaller bubbles with larger surface area, which is beneficial to more efficiently adsorb residual hydrogen atoms and micron or submicron inclusions in the melt and carry them to the liquid surface; thereby the residual amount of gas in the melt, especially hydrogen, is improved, the melt is purified, the solidification core is reduced in later stage, which is beneficial to reduce the bubbles on the surface of the wire, refine the grains, refine the precipitated phase, and improve the tensile strength and torsion resistance and other properties. Then, the slag is removed by standing for 35-55min, and before continuous casting and rolling, ultrasonic treatment is carried out with ultrasonic power of 10-13Kw and frequency of 2-3KHz; through high-power ultrasonic treatment, part of the precipitated phase in the melt is dispersed, so as to form smaller and more dispersed precipitated phase, which is beneficial to reduce or avoid the generation of large precipitated phase in the later solidification process under the condition of high Fe and high Si, and is beneficial to improve the tensile strength and torsion resistance and other properties.

[0083] (4) Continuous casting and rolling, the entry temperature is 560-570℃, and the aluminum alloy round rod with a diameter of 9-10mm is continuously cast and rolled;

[0084] (5) the aluminum alloy round rod is solid-solved at a low temperature of 540-560 °C for 40-55 h, and then is aged at a low temperature of 310-330 °C for 67-77 h; through the longer time of low-temperature solid solution and low-temperature aging treatment, the recrystallization and grain coarsening are effectively inhibited, the fine-grained structure is maintained, the grain coarsening is avoided, the more uniform dispersion of the nano-dispersed phase is promoted, the risk of cracks generated in the later torsion process is reduced, the tensile strength and toughness are avoided to be reduced, and the torsion resistance is affected.

[0085] (6) the aluminum alloy round rod is drawn into an aluminum alloy wire, and finally is annealed at 170-190 °C to obtain a rare earth modified high-strength torsion-resistant aluminum alloy cable with a wire diameter of 0.9-1.5 mm. It should be noted that the rare earth modified high-strength torsion-resistant aluminum alloy cable here specifically refers to an aluminum alloy wire cable without an insulating layer.

[0086] The aluminum alloy wire prepared by the above method is sampled (on the cross section of the aluminum alloy wire), and scanning electron microscope pictures (uniform field area: a region with a length of 45 microns and a width of 80 microns is selected) of different regions (for example, the surface region of the aluminum alloy wire, the region 60 microns inward from the surface) with precipitated particles (which can include constituent particles, intermetallic particles, oxides, precipitates or hardening particles, etc.) are obtained by scanning electron microscopy, the precipitated particle area and the particle number are counted, and the particle area rate (particle area / field area) is ; the number of precipitated particles is 0.007-0.15 / μm 2 ; and the aluminum alloy wire surface is bubble-free. Preferably, the particle area rate (particle area / field area) is ; the number of precipitated particles is 0.12-0.14 / μm 2 ; it can be seen that more fine precipitated particle phases are generated on the surface of the aluminum alloy wire, the possibility of crack generation is reduced, and the tensile strength and torsion resistance performance are more improved.

[0087] Example 1

[0088] A rare earth modified high-strength torsion-resistant aluminum alloy cable is composed of the following components by mass percentage:

[0089] Si 0.33%, Fe 0.37%, Mg 0.23% (Mg / Si=0.71), rare earth Re 0.11% (of which rare earth Mn 0.08% (Mn / Fe is 0.22), Ni 0.06% (Ni / Fe is 0.16), Cu 0.07%, Zr 0.07%, Nb 0.09%, B 0.003%, Mn+Ni=0.14%, Zr+Nb=0.16%; rare earth Re includes lanthanum (La), cerium (Ce), and erbium (Er); Er is 0.04%, wherein erbium (Er) accounts for 28% of the total mass of Zr+Nb, and the balance is aluminum.

[0090] The method for preparing the above aluminum alloy cable is as follows: a method for preparing a rare earth modified high-strength torsion-resistant aluminum alloy cable, comprising the following steps:

[0091] (1) Selecting industrial pure aluminum ingot, Si source, Fe source, Mg source, rare earth source, Mn source, Ni source, Cu source, Zr source, Nb source, and B source as raw materials, and performing batching according to the designed composition.

[0092] (2) Heating and melting the industrial pure aluminum at 735-750°C, adding the above raw materials, and fully stirring after melting to make the composition of the aluminum alloy liquid uniform;

[0093] (3) Performing in-furnace refining, degassing, and impurity removal treatment on the aluminum alloy liquid, at 735-740°C and an argon flow rate of 35 L / min, and at 710-715°C and an argon flow rate of 19 L / min. Then, standing for 45 min to remove slag, and before continuous casting and rolling, performing ultrasonic treatment at an ultrasonic power of 12 kW and a frequency of 2.4 kHz.

[0094] (4) Continuous casting and rolling, and entering the rolling temperature of 565°C to continuously cast and roll the aluminum alloy round rod to 9 mm;

[0095] (5) Solidifying the aluminum alloy round rod at a low temperature of 557°C for 53 h, and then aging at a low temperature of 328°C for 71 h;

[0096] (6) Drawing the aluminum alloy round rod into an aluminum alloy wire, and finally annealing at 187°C to obtain a rare earth modified high-strength torsion-resistant aluminum alloy cable, with a wire diameter of 1.2 mm.

[0097] Performance detection is as follows: tensile strength 191 MPa; elongation 23%; electrical conductivity 65% IACS; no cracks and twisting in 1440° torsion test under normal temperature conditions for 10,000 cycles; wire breakage rate 0.40% in 1440° torsion test under 45°C conditions for 15,000 cycles; and scanning electron microscope detection result: particle area rate is ; and the number of precipitated particles is 0.13446 / μm 2 . The above detection is the average value of multiple samples.

[0098] Example 2:

[0099] The rare earth modified high-strength torsion-resistant aluminum alloy cable composition and preparation method of Example 1 are basically the same, except that: Mn is 0.09%, Mn+Ni=0.15%;

[0100] Performance detection is as follows: tensile strength 193Mpa; elongation 22%; electrical conductivity 65%IACS, 10000 cycles of 1440° torsion test at room temperature without cracks and distortion, 15000 cycles of 1440° torsion test at 45°C with a wire breakage rate of 0.44%, and scanning electron microscope detection results: particle area rate is ; and the number of precipitated particles is 0.12667 / μm 2 Comparing Example 1 and Example 2, it can be seen that the contents of Mn and Ni are high, the Mn content is high, and based on the competition relationship between Mn and Fe, Mn is beneficial to improving the tensile strength, but is not conducive to improving the wire breakage rate and other properties in the 15000 cycle 1440° torsion test at 45°C.

[0101] Example 3:

[0102] The rare earth modified high-strength torsion-resistant aluminum alloy cable composition and preparation method of Example 1 are basically the same, except that: Zr is 0.09%, Nb is 0.13%, and Zr+Nb=0.22%;

[0103] Performance detection is as follows: tensile strength 185Mpa; elongation 21%; electrical conductivity 65%IACS, 10000 cycles of 1440° torsion test at room temperature without cracks and distortion, 15000 cycles of 1440° torsion test at 45°C with a wire breakage rate of 0.52%, and scanning electron microscope detection results: particle area rate is ; and the number of precipitated particles is 0.11112 / μm 2 Comparing Example 1 and Example 3, it can be seen that the sum of Zr+Nb is large, the particle area rate is large, and the number of precipitated particles is reduced, that is, the nano-precipitated phase is aggregated and grown, which is not conducive to improving the tensile strength and torsion resistance.

[0104] Example 4:

[0105] The rare earth modified high-strength torsion-resistant aluminum alloy cable composition and preparation method of Example 1 are basically the same, except that: Zr is 0.06%, Nb is 0.08%, and Zr+Nb=0.14%;

[0106] Performance detection is as follows: tensile strength 178Mpa; elongation 20%; electrical conductivity 64%IACS, 10000 cycles of 1440° torsion test at room temperature without cracks and distortion, 15000 cycles of 1440° torsion test at 45°C with a wire breakage rate of 0.54%, and scanning electron microscope detection results: particle area rate is ; the number of precipitated particles is 0.10011 / μm 2 Comparing Example 1 and Example 4, it can be seen that the sum of Zr+Nb is reduced, the particle area ratio is reduced, the number of precipitated particles is reduced, and the nano-precipitated phase is reduced, which is not conducive to improving the tensile strength and torsion resistance.

[0107] Example 5:

[0108] The composition and preparation method of the rare earth modified high-strength and torsion-resistant aluminum alloy cable of Example 1 are basically the same, except that the content of Er is 0.08%.

[0109] Performance testing is as follows: tensile strength 183 Mpa; elongation 22%; electrical conductivity 65% IACS; 1440° torsion test under normal temperature conditions for 10000 cycles has no cracks and torsion; the filament breakage rate is 0.46% in the 1440° torsion test under 45°C conditions for 15000 cycles; and the scanning electron microscope detection result is that the particle area ratio is ; the number of precipitated particles is 0.12676 / μm 2 Comparing Example 1 and Example 5, it can be seen that the content of Er is reduced, the particle area ratio is reduced, the number of precipitated particles is reduced, and the nano-precipitated phase is reduced, which is not conducive to improving the tensile strength and torsion resistance.

[0110] Example 6:

[0111] The composition and preparation method of the rare earth modified high-strength and torsion-resistant aluminum alloy cable of Example 1 are basically the same, except that it does not contain Er.

[0112] Performance testing is as follows: tensile strength 171 Mpa; elongation 20%; electrical conductivity 62% IACS; 1440° torsion test under normal temperature conditions for 10000 cycles has no cracks and torsion; the filament breakage rate is 0.58% in the 1440° torsion test under 45°C conditions for 15000 cycles; and the scanning electron microscope detection result is that the particle area ratio is ; the number of precipitated particles is 0.11981 / μm 2 Comparing Example 1 and Example 6, it can be seen that it does not contain Er, the particle area ratio is increased, and the number of precipitated particles is reduced, that is, the nano-precipitated phase is aggregated and grown, which is not conducive to improving the tensile strength and torsion resistance.

[0113] Example 7:

[0114] The composition and preparation method of the rare earth modified high-strength and torsion-resistant aluminum alloy cable of Example 1 are basically the same, except that the content of Er is 0.08%.

[0115] Performance test as follows: tensile strength 189Mpa; elongation 23%; electrical conductivity 65% IACS, 10000 cycles of 1440° twist test at room temperature without cracks and distortion, 15000 cycles of 1440° twist test at 45℃ with 0.42% wire breakage rate, scanning electron microscope test results: particle area rate is ; precipitated particle number is 0.14708 per μm 2 . Comparing example 1 and example 7, it is known that the increase of Er content does not change the particle area rate, but increases the precipitated particle number, and the nano precipitated phase becomes smaller, which is not conducive to improving the tensile strength and twist resistance.

[0116] Example 8:

[0117] The composition and preparation method of the rare earth modified high-strength and twist-resistant aluminum alloy cable of example 1 are basically the same, except that the preparation method does not use ultrasonic treatment.

[0118] Performance test as follows: tensile strength 167Mpa; elongation 19%; electrical conductivity 62% IACS, 10000 cycles of 1440° twist test at room temperature without cracks and distortion, 15000 cycles of 1440° twist test at 45℃ with 0.61% wire breakage rate, scanning electron microscope test results: particle area rate is ; precipitated particle number is 0.09157 per μm 2 . Comparing example 1 and example 8, it is known that the preparation method does not use ultrasonic treatment, which is not conducive to the formation of finer and dispersed precipitated phase, and is not conducive to reducing or avoiding the generation of large precipitated phase during the later solidification process under the conditions of high Fe and high Si, and reducing the tensile strength and twist resistance and other properties.

[0119] Example 9:

[0120] The composition and preparation method of the rare earth modified high-strength and twist-resistant aluminum alloy cable of example 1 are basically the same, except that the preparation method uses solid solution temperature of 600℃ and aging temperature of 360℃.

[0121] Performance test as follows: tensile strength 161Mpa; elongation 18%; electrical conductivity 61% IACS, 10000 cycles of 1440° twist test at room temperature without cracks and distortion, 15000 cycles of 1440° twist test at 45℃ with 0.64% wire breakage rate, scanning electron microscope test results: particle area rate is ; precipitated particle number is 0.12001 per μm 2 . Comparing example 1 and example 9, it is known that the solid solution temperature and aging temperature in the preparation method are higher, which is not conducive to promoting the uniform dispersion of nano dispersed phase, increasing the risk of cracks during the later twist process, and reducing the tensile strength and twist resistance and other properties.

[0122] Comparative Example 1

[0123] The composition and preparation method of the rare earth modified high-strength torsion-resistant aluminum alloy cable of Example 1 are basically the same, except that the Mg content is 0.43%.

[0124] Performance testing is as follows: tensile strength 153 Mpa; elongation 15%; electrical conductivity 60% IACS, 10000 cycles of 1440° torsion test at room temperature without cracks and distortion, 15000 cycles of 1440° torsion test at 45°C with a broken filament rate of 0.51%, and scanning electron microscope detection results: particle area rate is ; the number of precipitated particles is 0.09141 / μm 2 . Comparing Example 1 and Comparative Example 1, it can be seen that the Mg content is too high, the Mg / Si is as high as 1.3, i.e. high Mg / Si, the precipitated particles are coarse, and the tensile strength and torsion resistance performance are significantly reduced.

[0125] Comparative Example 2

[0126] The composition and preparation method of the rare earth modified high-strength torsion-resistant aluminum alloy cable of Example 1 are basically the same, except that the Re content is 0.3%.

[0127] Performance testing is as follows: tensile strength 187 Mpa; elongation 22%; electrical conductivity 64% IACS, 10000 cycles of 1440° torsion test at room temperature without cracks, 15000 cycles of 1440° torsion test at 45°C with a broken filament rate of 0.74%, and scanning electron microscope detection results: particle area rate is ; the number of precipitated particles is 0.13012 / μm 2 . Comparing Example 1 and Comparative Example 2, it can be seen that the Re content is too high, the precipitated particles are large, and the torsion resistance performance is significantly reduced.

[0128] Comparative Example 3

[0129] The composition and preparation method of the rare earth modified high-strength torsion-resistant aluminum alloy cable of Example 1 are basically the same, except that no rare earth is added.

[0130] Performance testing is as follows: tensile strength 135 Mpa; elongation 17%; electrical conductivity 60% IACS, 10000 cycles of 1440° torsion test at room temperature with cracks, and scanning electron microscope detection results: particle area rate is ; the number of precipitated particles is 0.07241 / μm 2 , and bubbles appear on the surface of the aluminum alloy wire. Comparing Example 1 and Comparative Example 3, it can be seen that without adding Re, the precipitated particles are significantly large, and the tensile strength, torsion resistance performance, electrical conductivity, and elongation performance are significantly reduced.

[0131] Comparative Example 4

[0132] The rare earth modified high-strength torsion-resistant aluminum alloy cable composition and preparation method of Example 1 are basically the same, except that Fe is 0.12%.

[0133] Performance testing is as follows: tensile strength 161 Mpa; elongation 17%; electrical conductivity 56% IACS, and cracks appear in the 1440° torsion test under normal temperature conditions for 10000 cycles. Comparing Example 1 and Comparative Example 4, it can be seen that a low Fe content, i.e., a low Fe content design, significantly reduces the tensile strength, torsion resistance, elongation, and other properties.

[0134] Comparative Example 5

[0135] The rare earth modified high-strength torsion-resistant aluminum alloy cable composition and preparation method of Example 1 are basically the same, except that Si is 0.20%.

[0136] Performance testing is as follows: tensile strength 164 Mpa; elongation 16%; electrical conductivity 58% IACS, and cracks appear in the 1440° torsion test under normal temperature conditions for 10000 cycles. Comparing Example 1 and Comparative Example 5, it can be seen that a low Si content, i.e., a low Si content design, significantly reduces the tensile strength, torsion resistance, electrical conductivity, elongation, and other properties.

[0137] Comparative Example 6

[0138] The rare earth modified high-strength torsion-resistant aluminum alloy cable composition and preparation method of Example 1 are basically the same, except that low-temperature small argon flow treatment is not used.

[0139] Performance testing is as follows: tensile strength 182 Mpa; elongation 21%; electrical conductivity 64% IACS, and no cracks and torsion occur in the 1440° torsion test under normal temperature conditions for 10000 cycles, the filament breakage rate is 0.67% in the 1440° torsion test under 45°C conditions for 15000 cycles, and the scanning electron microscope detection result is that the particle area rate is ; the number of precipitated particles is 0.12457 per μm 2 , and bubbles appear on the surface of the aluminum alloy wire. Comparing Example 1 and Comparative Example 5, it can be seen that low-temperature small argon flow treatment is not used in the preparation method; the precipitated phase changes greatly, bubbles appear on the surface of the aluminum alloy wire, and the torsion resistance performance is significantly reduced.

[0140] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, and are not intended to limit the present application; although the present application has been described in detail with reference to the above embodiments, those skilled in the art should understand that the technical solutions recorded in the above embodiments can be modified, or some or all of the technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A rare earth modified high strength torsionally resistant aluminum alloy cable characterized by, consists of the following ingredients in percentage by mass: Si 0.31%-0.34%; Fe 0.33%-0.38%; Mg / Si=0.65-0.91; rare earths k = 0.19-0.28; Mn / Fe is 0.21-0.26; Ni / Fe is 0.12-0.18; Cu 0.06%-0.09%; Zr 0.06％-0.09％； Nb 0.08%-0.13%; B 0.002％-0.005％； The balance is aluminum; wherein, 0.12%≤Mn+Ni≤0.14%; the surface area of the aluminum alloy wire is detected by a scanning electron microscope to obtain precipitated particles, the area rate of the particles is ; the number of the precipitated particles is 0.007-0.15 per μm 2 , and the aluminum alloy wire surface is free of bubbles; the rare earth Re includes La, Ce and Er; wherein, Er accounts for 20-30% of the total added mass of Zr+Nb.

2. The rare earth modified high strength, torsionally resistant aluminum alloy cable of claim 1, wherein, wherein 0.15%≤Zr+Nb≤0.17%.

3. The rare earth modified high strength, kink resistant, aluminum alloy electrical cable of claim 1, wherein, Tensile strength≥180Mpa; elongation≥19%; electrical conductivity≥63%IACS, no crack and distortion in 1440°twist test under normal temperature condition for 10000 cycles, and the wire breaking rate is less than 0.9% in 1440°twist test under 45℃ condition for 15000 cycles.

4. A process for the production of a rare earth modified high strength torsionally resistant aluminum alloy electrical cable, the rare earth modified high strength torsionally resistant aluminum alloy electrical cable of any one of claims 1-3, characterized in that, The specific method comprises: (1) selecting industrial pure aluminum ingot, Si source, Fe source, Mg source, rare earth source, Mn source, Ni source, Cu source, Zr source, Nb source, and B source as raw materials, and dosing according to the designed components; (2) heating and melting the industrial pure aluminum ingot at 710-750℃, adding the raw materials except the industrial pure aluminum ingot, and fully stirring the molten aluminum alloy after melting to make the components of the molten aluminum alloy uniform; (3) performing in-furnace refining, degassing and impurity removal treatment on the molten aluminum alloy, stirring at high temperature of 730-740℃ using large argon flow, argon flow being 33-38L / min; stirring at low temperature of 705-715℃ using small argon flow, argon flow being 18-21L / min to facilitate deep hydrogen removal; and then standing for 35-55min to remove slag; (4) continuous casting and rolling, the entry rolling temperature being 560-570℃ to continuously cast and roll the aluminum alloy round rod with a diameter of 9-10mm; (5) solid solution and aging treatment of the aluminum alloy round rod; (6) drawing the aluminum alloy round rod into aluminum alloy wire, and annealing to obtain the rare earth modified high-strength and torsion-resistant aluminum alloy cable, the wire diameter being 0.9-1.5mm.

5. The method of producing a rare earth modified high strength, kink resistant aluminum alloy electrical cable according to claim 4, characterized in that, In step (3), before continuous casting and rolling, ultrasonic treatment is performed, the ultrasonic power being 10-13Kw and the frequency being 2-3KHz.

6. The method of producing a rare earth modified high strength, kink resistant aluminum alloy electrical cable of claim 4, wherein, In step (5), the aluminum alloy round rod is solid-solved at low temperature of 540-560℃ for 40-55h, and then aged at low temperature of 310-330℃ for 67-77h.

7. The method of producing a rare earth modified high strength, kink resistant aluminum alloy electrical cable of claim 4, wherein, In step (6), annealing is performed at 170-190℃.