Al-Cu-RE series rare earth aluminum alloy, preparation method thereof and heat-resistant cable

Abstract

The invention provides an Al-Cu-RE series rare earth aluminum alloy which contains Al, Cu and RE, the aluminum alloy material is characterized by further comprising the following components in percentage by mass: 0.01%-0.6% of Cu, 0.001%-0.2% of RE, 0%-0.7% of Mg, 0%-0.3% of Si, 0%-0.2% of In, 0%-0.1% of B, 0%-0.3% of Mo and 0%-0.3% of Sn. The aluminum alloy material is prepared from the following components in percentage by mass: 0.01%-0.6% of Cu, 0.001%-0.2% of RE, 0%-0.7% of Mg, 0%-0.3% of Si, 0%-0.2% of In, 0%-0.1% of B, 0%-0.3% of Mo and 0%-0.3% of Sn. The invention further provides a preparation method of the Al-Cu-RE series rare earth aluminum alloy and a heat-resistant cable. On the basis of keeping low cost and low process complexity, the Al-Cu-RE series rare earth aluminum alloy for the heat-resistant cable, which is excellent in comprehensive performance (especially mechanical performance, heat resistance, corrosion resistance and conductivity), can be obtained only by adopting fewer types of low-price elements.

Description

Technical Field

[0001] The present invention relates to the technical field of aluminum alloys, and in particular to an Al-Cu-RE series rare earth aluminum alloy, a method for preparing the Al-Cu-RE series rare earth aluminum alloy, and a heat-resistant cable using the Al-Cu-RE series rare earth aluminum alloy. Background Art

[0002] With copper resources becoming increasingly scarce, aluminum alloys have attracted research interest as copper replacements. Currently, aluminum alloy conductor materials in my country are primarily categorized into three categories: high-conductivity aluminum alloy conductor materials, high-strength and high-conductivity aluminum alloy materials, and high-strength, high-conductivity, and heat-resistant aluminum alloy conductor materials. High-conductivity aluminum alloy conductor materials primarily include Al-Fe aluminum alloys, Al-Cu aluminum alloys, and electrical aluminum (such as electrical aluminum 1350 or electrical aluminum 1B90). High-conductivity aluminum alloy conductor materials are soft wire aluminum alloys with generally low mechanical properties and creep resistance, but high electrical conductivity (reaching 61-63% IACS), and are generally used in low-voltage transmission lines. High-strength and high-conductivity aluminum alloy materials primarily include Al-Mg-Si aluminum alloys. These alloys offer excellent mechanical properties and corrosion resistance, but low electrical conductivity (generally below 58% IACS), and are primarily used in overhead lines, such as those used in ultra-high voltage, long-span transmission lines along the Yangtze and Han Rivers. High-strength, high-conductivity, and heat-resistant aluminum alloy conductor materials primarily include Al-Zr-RE series aluminum alloys. These materials offer excellent electrical conductivity, mechanical properties, and heat resistance, and can be used in high-temperature environments below 150°C.

[0003] The applicant established an aluminum alloy new material research and development department in 2021 and conducted research and development on aluminum alloys for heat-resistant cables, such as Al-Cu aluminum alloys. The study found that as the requirements for the performance of aluminum alloys for heat-resistant cables become higher and higher, in order to obtain aluminum alloys for heat-resistant cables with good comprehensive performance, a variety of elements with different functions are usually added to aluminum. For example, in patent CN102978448B, in which Lin Zemin is the inventor, 36 elements are added to aluminum. The addition of too many elements will increase the cost (the total content of elements is too high and there is no lack of expensive elements added) and increase the process complexity. Moreover, the addition of too many elements means that the existing preparation process of aluminum alloys for heat-resistant cables does not improve the comprehensive performance of aluminum alloys for heat-resistant cables in a targeted manner on the basis of reducing costs and process complexity. To this end, the applicant has continuously innovated experiments and proposed a new invention of Al-Cu-RE rare earth aluminum alloys for heat-resistant cables with excellent comprehensive performance, which can be obtained by using only a small number of low-priced elements while maintaining low cost and low process complexity. Summary of the Invention

[0004] In response to the above-mentioned defects of the prior art, the present invention provides an Al-Cu-RE series rare earth aluminum alloy, which aims to obtain an Al-Cu-RE series rare earth aluminum alloy for heat-resistant cables with excellent comprehensive performance (especially mechanical properties, heat resistance, corrosion resistance, and electrical conductivity) by using only a small number of low-priced elements while maintaining low cost and low process complexity.

[0005] The present invention provides an Al-Cu-RE series rare earth aluminum alloy, which contains Al. The Al-Cu-RE series rare earth aluminum alloy further contains 0.01-0.6% by mass of Cu, 0.001-0.2% by mass of RE, 0-0.7% by mass of Mg, 0-0.3% by mass of Si, 0-0.2% by mass of In, 0-0.1% by mass of B, 0-0.3% by mass of Mo, and 0-0.3% by mass of Sn.

[0006] Furthermore, the Al-Cu-RE rare earth aluminum alloy also contains 0.01-0.6% Cu by mass, 0.001-0.2% RE by mass, 0.01-0.7% Mg by mass, 0.001-0.3% Si by mass, 0.001-0.2% In by mass, 0.001-0.1% B by mass, 0.001-0.3% Mo by mass, and 0.001-0.3% Sn by mass.

[0007] Furthermore, the mass ratio of In to B is 0.1-10:1.

[0008] Furthermore, at least one of the following conditions is met:

[0009] The mass ratio of Mg to Si is 0.2-40:1;

[0010] The mass ratio of Cu to Si is 0.5-30:1;

[0011] The mass ratio of Mg to In is 0.3-40:1;

[0012] The mass ratio of Cu to In is 0.3-40:1;

[0013] The mass ratio of Mg, Sn, and Si is 1-20:0.5-5:1;

[0014] RE is at least one of La, Ce, Pr, Nd, Er, Sm, Y, and Gd.

[0015] Furthermore, at least one of the following conditions is met:

[0016] The Al-Cu-RE series rare earth aluminum alloy further contains Sb in an amount of 0-0.5% by mass;

[0017] The Al-Cu-RE series rare earth aluminum alloy further contains Sr in a mass percentage content of 0-0.2%;

[0018] The Al-Cu-RE series rare earth aluminum alloy further contains Bi in a mass percentage content of 0-0.3%;

[0019] The Al-Cu-RE series rare earth aluminum alloy further contains Ca in a mass percentage content of 0-0.5%;

[0020] The Al-Cu-RE series rare earth aluminum alloy further contains Ge in a mass percentage content of 0-0.3%.

[0021] Furthermore, the Al-Cu-RE series rare earth aluminum alloy further contains 0-0.3% by mass of Fe, wherein the mass ratio of Mg to Fe is 0.2-20:1, and the mass ratio of Si to Fe is 0.1-5:1.

[0022] Furthermore, the mass percentage content of Fe is 0.001-025%.

[0023] The present invention also provides a method for preparing an Al-Cu-RE series rare earth aluminum alloy, comprising the following steps:

[0024] The aluminum source is subjected to a first heating treatment to obtain aluminum liquid;

[0025] adding Cu, Mg, Si, RE, In, B, Mo, and Sn to the aluminum liquid and performing a second heating treatment to obtain an alloy liquid;

[0026] The alloy liquid is subjected to refining and slag removal treatments, and composition and content testing is performed;

[0027] After the composition and content are tested to be qualified, the alloy liquid after the refining and slagging treatment is subjected to continuous casting, continuous rolling and drawing to obtain aluminum alloy wire; and

[0028] An aluminum alloy wire is subjected to aging treatment to obtain an Al-Cu-RE series rare earth aluminum alloy, wherein the Al-Cu-RE series rare earth aluminum alloy contains Al, 0.01-0.6% by mass of Cu, 0.001-0.2% by mass of RE, 0-0.7% by mass of Mg, 0-0.3% by mass of Si, 0-0.2% by mass of In, 0-0.1% by mass of B, 0-0.3% by mass of Mo, and 0-0.3% by mass of Sn.

[0029] Furthermore, at least one of the following conditions is met:

[0030] The preparation method of the Al-Cu-RE series rare earth aluminum alloy further includes the step of adding at least one of Sb, Sr, Bi, Fe, Ca, and Ge to the aluminum liquid;

[0031] The aging treatment is a bipolar aging treatment, which includes the following steps: firstly performing a low-temperature aging treatment at a temperature of 100-150° C. for 1-150 hours; and then performing a high-temperature aging treatment at a temperature of 150-250° C. for 1-100 hours.

[0032] The present invention also provides a heat-resistant cable, which comprises a wire core and an insulating layer covering the wire core, wherein the material of the wire core is the Al-Cu-RE series rare earth aluminum alloy.

[0033] In the technical solution of the present invention, the Al-Cu-RE rare earth aluminum alloy contains 0.01-0.6% Cu by mass, 0.001-0.2% RE by mass, 0-0.7% Mg by mass, 0-0.3% Si by mass, 0-0.2% In by mass, 0-0.1% B by mass, 0-0.3% Mo by mass, and 0-0.3% Sn by mass. When these elements are added individually to the aluminum matrix, the improvement in the electrical conductivity and mechanical properties of the aluminum is limited, and may even have a negative effect on the electrical conductivity and mechanical properties of the aluminum. The present invention adds these elements to the aluminum matrix together, and the interaction between these elements can reduce each other's solid solubility in the aluminum matrix, thereby reducing the adverse effects of certain elements on electrical conductivity and improving electrical conductivity. The elements can also dissolve into other precipitated phases and secondary phases to form strengthening phases, thereby significantly improving the overall performance of the aluminum alloy. DETAILED DESCRIPTION

[0034] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0035] One embodiment of the present invention provides an Al-Cu-RE rare earth aluminum alloy, which contains 0.01-0.6% Cu by mass, 0.001-0.2% RE by mass, 0-0.7% Mg by mass, 0-0.3% Si by mass, 0-0.2% In by mass, 0-0.3% Sn by mass, Al and unavoidable impurities.

[0036] In one embodiment, the mass percentage content of Cu may be 0.01%, 0.05%, 0.1%, 0.15%, 0.2%, 0.25%, 0.3%, 0.31%, 0.32%, 0.33%, 0.34%, 0.35%, 0.4%, 0.45%, 0.5%, 0.55%, or 0.6%; the mass percentage content of Mg may be 0.01%, 0.05%, 0.1%, 0.15%, 0.2%, 0.25%, 0.3%, 0.31%, 0.32%, 0.33%, 0.34%, 0.35%, 0.4%, 0.45%, 0.5%, 0.55%, or 0.6%. 33%, 0.34%, 0.35%, 0.4%, 0.45%, 0.5%, 0.55%, 0.6%, 0.65%, or 0.7%; the mass percentage content of Si can be specifically 0.001%, 0.005%, 0.01%, 0.05%, 0.1%, 0.15%, 0.2%, 0.21%, 0.25%, or 0.3%; the mass percentage content of RE can be specifically 0.001%, 0.005%, 0.01%, 0.02%, 0.03%, 0.04%, 0.05%. %, 0.06%, 0.07%, 0.08%, 0.09%, 0.1%, 0.11%, 0.12%, 0.13%, 0.14%, 0.15%, 0.16%, 0.17%, 0.18%, 0.19%, or 0.2%; the mass percentage content of In can be 0.001%, 0.005%, 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.1%, 0.11%, 0. The mass percentage content of Sn can be 0.001%, 0.005%, 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.1%, 0.11%, 0.12%, 0.13%, 0.14%, 0.15%, 0.2%, 0.25%, or 0.3%.

[0037] The mass ratio of Mg, Sn, and Si is 1-20:0.5-5:1. Specifically, the mass ratio of Mg, Sn, and Si is 1:0.5:1, 1:1:1, 1:1.5:1, 1:2:1, 1:2.5:1, 1:3:1, 1:4:1, 1:4.5:1, 1:5:1, 5:0.5:1, 5:1:1, 5:1.5:1, 5:2:1, 5:2.5:1, 5:3:1, 5:4:1, 5:4.5:1, 5:5:1, 10:0.5:1, 10:1:1, 10:1.5:1, 10:2:1, 10:2 .5:1, 10:3:1, 10:4:1, 10:4.5:1, 10:5:1, 15:0.5:1, 15:1:1, 15:1.5:1, 15:2:1, 15:2.5:1, 15:3:1, 15:4:1, 15:4.5:1, 15:5:1, 20:0.5:1, 20:1:1, 20:1.5:1, 20:2:1, 20:2.5:1, 20:3:1, 20:4:1, 20:4.5:1, or 20:5:1.

[0038] The mass ratio of Mg to Si is 0.2-40:1. Specifically, the mass ratio of Mg to Si is 0.2:1, 0.5:1, 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, 11:1, 12:1, 13:1, 14:1, 15:1, 16:1, 17:1, 18:1, 19:1, 20:1, 30:1, or 40:1. Within this mass ratio range, as the mass ratio of Mg to Si increases, the conductive strength gradually increases.

[0039] The mass ratio of Cu to Si can be 0.5-30:1. Specifically, the mass ratio of Cu to Si is 0.5:1, 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, 11:1, 12:1, 13:1, 14:1, 15:1, 16:1, 17:1, 18:1, 19:1, 20:1, 25:1, 30:1, 35:1, or 40:1. Within this mass ratio range, as the Cu / Si mass ratio increases, the tensile strength gradually increases.

[0040] The mass ratio of Mg to In is 0.3-40:1. Specifically, the mass ratio of Mg to In is 0.3:1, 0.5:1, 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, 11:1, 12:1, 13:1, 14:1, 15:1, 16:1, 17:1, 18:1, 19:1, 20:1, 25:1, 30:1, 35:1, or 40:1. Within this mass ratio range, as the Mg / In mass ratio increases, the conductive strength gradually increases.

[0041] The mass ratio of Cu to In is 0.3-40:1. Specifically, the mass ratio of Cu to In is 0.3:1, 0.5:1, 1:

[0042] 1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, 11:1, 12:1, 13:1, 14:1, 15:1, 16:1, 17:1, 18:1, 19:1, 20:1, 25:1, 30:1, 35:1, or 40: 1. Within this mass ratio range, as the mass ratio of Cu / In increases, the tensile strength gradually increases.

[0043] RE is at least one of La, Ce, Pr, Nd, Er, Sm, Y, and Gd.

[0044] The Al-Cu-RE rare earth aluminum alloy further contains 0-0.5% by mass of Sb. The mass percentage of Sb can specifically be 0.05%, 0.1%, 0.15%, 0.2%, 0.25%, 0.3%, 0.35%, 0.4%, 0.45%, or 0.5%.

[0045] The Al-Cu-RE rare earth aluminum alloy further contains 0-0.2% by mass of Sr. The mass percentage of Sr can specifically be 0.001%, 0.005%, 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.1%, 0.11%, 0.12%, 0.13%, 0.14%, 0.15%, or 0.2%.

[0046] The Al-Cu-RE rare earth aluminum alloy further contains 0-0.3% by mass of Zn, which may be 0.001%, 0.01%, 0.04%, 0.05%, 0.1%, 0.15%, 0.2%, 0.25%, or 0.3% by mass.

[0047] The Al-Cu-RE rare earth aluminum alloy further contains 0-0.1% by mass of Be. The Be content by mass can be 0.001%, 0.005%, 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, or 0.1%.

[0048] The Al-Cu-RE rare earth aluminum alloy further contains 0-0.3% by mass of Bi, which may be 0.001%, 0.01%, 0.04%, 0.05%, 0.1%, 0.15%, 0.2%, 0.25%, or 0.3% by mass.

[0049] The Al-Cu-RE rare earth aluminum alloy further contains 0-0.3% by mass of Mo. The mass percentage of Mo can specifically be 0.001%, 0.01%, 0.04%, 0.05%, 0.1%, 0.15%, 0.2%, 0.25%, or 0.3%.

[0050] The Al-Cu-RE rare earth aluminum alloy further contains 0-0.3% by mass of Cd, which may be 0.001%, 0.01%, 0.04%, 0.05%, 0.1%, 0.15%, 0.2%, 0.25%, or 0.3% by mass.

[0051] The Al-Cu-RE rare earth aluminum alloy further contains 0-0.8% by mass of Co. The mass percentage of Co can specifically be 0.01%, 0.05%, 0.1%, 0.2%, 0.25%, 0.3%, 0.35%, 0.4%, 0.45%, 0.5%, 0.55%, 0.6%, 0.65%, 0.7%, 0.75%, or 0.8%.

[0052] The Al-Cu-RE rare earth aluminum alloy further contains 0-0.5% by mass of Ca. The mass percentage of Ca can specifically be 0.05%, 0.1%, 0.15%, 0.2%, 0.25%, 0.3%, 0.35%, 0.4%, 0.45%, or 0.5%.

[0053] The Al-Cu-RE rare earth aluminum alloy further contains 0-0.3% by mass of Ge, wherein the mass percentage of Ge can be 0.001%, 0.01%, 0.04%, 0.05%, 0.1%, 0.15%, 0.2%, 0.25%, or 0.3%.

[0054] The Al-Cu-RE rare earth aluminum alloy further contains 0-0.3% by weight of Fe. The Fe content by weight can specifically be 0.001%, 0.005%, 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.1%, 0.11%, 0.12%, 0.13%, 0.14%, 0.15%, 0.2%, 0.25%, or 0.3%.

[0055] The mass ratio of Mg to Fe may be 0.2-20:1, specifically 0.2:1, 0.5:1, 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, 11:1, 12:1, 13:1, 14:1, 15:1, 16:1, 17:1, 18:1, 19:1, or 20:1.

[0056] The mass ratio of Si to Fe may be 0.1-5:1, specifically 0.1:1, 0.15:1, 0.2:1, 0.25:1, 0.3:1, 0.4:1, 0.5:1, 0.6:1, 0.7:1, 0.8:1, 0.9:1, 1:1, 2:1, 3:1, 4:1, or 5:1.

[0057] The Al-Cu-RE rare earth aluminum alloy further contains Sc in an amount of 0-0.3% by mass. The Sc content can be 0.001%, 0.005%, 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.1%, 0.11%, 0.12%, 0.13%, 0.14%, 0.15%, 0.16%, 0.17%, 0.18%, 0.19%, or 0.2%. The Sn content can be 0.001%, 0.01%, 0.04%, 0.05%, 0.1%, 0.15%, 0.2%, 0.25%, or 0.3% by mass.

[0058] The Al-Cu-RE rare earth aluminum alloy further contains 0-0.3% by mass of Zr, wherein the Zr content can be 0.001%, 0.01%, 0.04%, 0.05%, 0.1%, 0.15%, 0.2%, 0.25%, or 0.3%.

[0059] The mass ratio of Sc to Fe can be 0.1-10:1, specifically 0.1:1, 0.2:1, 0.5:1, 1:1, 2:

[0060] 1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, or 10:1.

[0061] The mass ratio of Mg to Sc is 0.1-20:1. Specifically, the mass ratio of Mg to Sc is 0.1:1, 0.2:1, 0.5:1, 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, 11:1, 12:1, 13:1, 14:1, 15:1, 16:1, 17:1, 18:1, 19:1, or 20:1. Within this mass ratio range, as the mass ratio of Mg to Sc increases, the conductive strength gradually increases.

[0062] The mass ratio of Cu to Sc can be 1-30:1. Specifically, the mass ratio of Cu to Sc is 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, 11:1, 12:1, 13:1, 14:1, 15:1, 16:1, 17:1, 18:1, 19:1, 20:1, 25:1, or 30:1. Within this mass ratio range, as the Cu / Sc mass ratio increases, the tensile strength gradually increases.

[0063] The mass ratio of Sc to Zr is 0.5-2.5:1. Specifically, it can be 0.5:1, 0.6:1, 0.7:1, 0.8:1, 0.9:1, 1.1:1, 1.2:1, 1.3:1, 1.4:1, 1.5:1, 2:1, or 2.5:1.

[0064] The Al-Cu-RE rare earth aluminum alloy further contains 0-0.1% by mass of B. The mass percentage of B can specifically be 0.001%, 0.005%, 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, or 0.1%.

[0065] The mass ratio of In to B is 0.1-10:1, for example, 0.1:1, 0.5:1, 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, or 10:1.

[0066] The mass ratio of Sc, In, and B is 0.1-15:0.1-10:1, preferably 1-10:1-5:1. The mass ratio of Sc, In, and B can specifically be 0.1:0.1:1, 0.5:0.1:1, 1:0.1:1, 5:0.1:1, 10:0.1:1, 15:0.1:1, 0.1:1:1, 0.5:1:1, 1:1:1, 5:1:1, 10:1:1, 15:1:1, 0.1:5:1, 0.5:5:1, 1:5:1, 5:5:1, 10:5:1, 15:5:1, 0.1:10:1, 0.5:10:1, 1:10:1, 5:10:1, 10:10:1, or 15:10:1.

[0067] The mass percentage content of the impurities is no more than 0.15%, and the mass percentage content of a single impurity is less than 0.05%.

[0068] In the technical solution of the present invention, the Al-Cu-RE rare earth aluminum alloy contains 0.01-0.6% Cu by mass, 0.001-0.2% RE by mass, 0-0.7% Mg by mass, 0-0.3% Si by mass, 0-0.2% In by mass, and 0-0.3% Sn by mass. When the above elements are added to the aluminum matrix alone, the improvement of the electrical conductivity and mechanical properties of aluminum is limited, and even has a negative effect on the electrical conductivity and mechanical properties of aluminum. The present invention adds the above elements to the aluminum matrix together. The interaction between the above elements can reduce the solid solubility of each other in the aluminum matrix, thereby reducing the adverse effects of certain elements on electrical conductivity and improving electrical conductivity. The elements can also dissolve into other precipitated phases and secondary phases to form strengthening phases, thereby significantly improving the comprehensive performance of the aluminum alloy. The Al-Cu-RE rare earth aluminum alloy utilizes a limited number of elements and is inexpensive. While RE and Sc are slightly more expensive, their relatively small usage significantly impacts the cost of the Al-Cu-RE rare earth aluminum alloy. Furthermore, RE and Sc possess unmatched mechanical and electrical properties. The interaction of these elements also promotes the precipitation volume fraction of strengthening phases, reducing the total amount of elements added to the aluminum matrix. Generally, in soft heat-resistant cables, the amount of alloying elements added is inversely proportional to the electrical conductivity and elongation, and directly proportional to the tensile strength and yield strength. In the soft state, to ensure that the electrical conductivity reaches the national standard value (greater than 61% IACS), the total amount of elements added to the cable aluminum alloy does not exceed 1.0 wt%. To ensure that the tensile strength is greater than 185 MPa, the total amount of elements added to the cable aluminum alloy generally exceeds 1.0 wt%. However, the electrical conductivity will definitely be lower than the national standard value (greater than 61% IACS). However, the present invention achieves better comprehensive performance (specifically, the tensile strength of the Al-Cu-RE rare earth aluminum alloy is greater than that of the hard alloy, the elongation of the Al-Cu-RE rare earth aluminum alloy is greater than that of the soft alloy, and the electrical conductivity is greater than 61% IACS) when the total amount of elements added to the aluminum alloy is less than 1.0 wt% while ensuring mechanical properties and electrical conductivity. This further reduces the cost of the Al-Cu-RE rare earth aluminum alloy. In summary, the present invention can obtain Al-Cu-RE rare earth aluminum alloy for heat-resistant cables with excellent comprehensive properties (especially mechanical properties, heat resistance, corrosion resistance, and electrical conductivity) by using only a small number of low-priced elements while maintaining low cost and low process complexity.

[0069] Elements such as Mg, Si, Ti, Mn, V, and Cr are the main harmful impurity elements that affect the electrical conductivity of aluminum. Their addition levels need to be reduced or they need to be treated to reduce their impact on electrical conductivity. In the technical solution of the present invention, the addition levels of Mg, Si, Cu, In, and Sn (which can reach 0.7%, 0.3%, 0.6%, 0.2%, and 0.3%, respectively) can be greater than the addition levels of Mg, Si, Cu, In, and Sn in the prior art (which can reach 0.3%, 0.08%, 0.25%, 0.1%, and 0.08%, respectively). This allows the Al-Cu-RE rare earth aluminum alloy to have better overall properties, especially mechanical properties, heat resistance, corrosion resistance, and electrical conductivity. The specific reasons are as follows:

[0070] (1) The amount of Si added can reach 0.3%, which can be greater than the amount of Si added in the prior art (Si exists in the aluminum matrix in a solid solution state, and its lattice constant is very different from that of Al, which can easily cause large lattice distortion and have a great influence on the electrical conductivity of aluminum. It is the main impurity element affecting the electrical conductivity of aluminum. Therefore, the amount of Si added in the prior art is small, usually not more than 0.08%). Si can react with Al and Fe to form (Al, Fe, Si) intermetallic compounds (it is understandable that the aluminum source usually contains Fe impurities. When there is no Fe impurity in the aluminum source used or Fe is not added to the aluminum matrix, Si will naturally not react with Fe to form iron-containing compounds). The amount of Mg added is sufficient, so that a large amount of Si can react with Al, Mg and Fe to form Mg2Si and AlFeMgSi, thereby eliminating or almost eliminating the impurities in the aluminum matrix. The elemental Si of the present invention can avoid the influence of excessive Si addition on the electrical conductivity of the aluminum alloy. The amount of Si added is set to be greater than the amount of Si added in the prior art. On the one hand, Si is beneficial to refine the primary crystal grains. On the other hand, Si reacts with Al, Mg and Fe to form compounds to improve the mechanical properties. It can also avoid the decrease in the electrical conductivity of the aluminum alloy caused by excessive Si. In this way, the amount of Si added in the present invention can be set to be greater than the amount of Si added in the prior art. This not only breaks the technical prejudice in the prior art that excessive Si addition affects the electrical conductivity of the aluminum alloy, but also improves the electrical conductivity and mechanical properties of the aluminum alloy when more Si is added. It can also avoid the cost increase caused by excessive addition of high-cost elements and the lack of targeted performance adjustment and process complexity caused by the addition of too many types of elements.

[0071] (2) The amount of Cu added can reach 0.6%, which can be greater than the amount of Cu added in the prior art (lower content of Cu has little effect on the electrical conductivity and mechanical properties of aluminum alloys, and higher content of Cu will reduce the electrical conductivity of aluminum alloys. Therefore, the amount of Cu added in the prior art is usually 0.18-0.25%). RE can greatly promote the precipitation of CuAl2 strengthening phase and (CuMg)Al2 strengthening phase, significantly improving the mechanical properties and electrical conductivity of aluminum alloys. Setting the amount of Cu added to be greater than the amount of Cu added in the prior art is beneficial to Cu to improve the electrical conductivity of aluminum alloys. On the other hand, the reaction of Cu with Mg and Al to form a dispersed compound avoids the decrease in the electrical conductivity of the aluminum alloy caused by excessive Cu. In this way, the amount of Cu added in the present invention can be set to be greater than the amount of Cu added in the prior art. This not only breaks the technical prejudice in the prior art that excessive addition of Cu affects the electrical conductivity of the aluminum alloy, but also improves the mechanical and electrical properties of the aluminum alloy when more Cu is added. It also avoids the cost increase caused by excessive addition of high-cost elements and the lack of targeted performance adjustment and process complexity caused by the addition of too many types of elements.

[0072] (3) The amount of Mg added can reach 0.7%, which can be greater than the amount of Mg added in the prior art (Mg exists in the alloy mainly in the form of solid solution strengthening. The atomic radius of Mg is quite different from that of aluminum. The higher the content of Mg in the aluminum solid solution, the more likely it is to cause lattice distortion and reduce the electrical conductivity of the aluminum alloy. Therefore, the amount of Mg added in the prior art is usually not more than 0.3%). Mg can react with Si and Sn to form Mg2Si and Mg2Sn phases. Some Mg will also be dissolved in CuAl2 phase and AlFeSi phase to form (CuMg)Al2 phase and AlFeSiMg phase, reducing the solid solubility of alloy elements in the matrix, which can improve the mechanical properties, electrical conductivity and fatigue resistance of aluminum alloy. The amount of Mg added can be large. Mg can react with Al, Fe, Sn (the amount added can be large), Si (the amount added can be large), Cu (the amount added can be large), and Cu (the amount added can be large). The amount of Mg added can be large) to react to form a second phase, avoiding excessive Mg solid solution causing lattice distortion of the aluminum alloy. Setting the amount of Mg added to be greater than the amount of Mg added in the prior art is beneficial to Mg in improving the mechanical properties of the aluminum alloy on the one hand, and on the other hand, Mg reacts with Si, Cu, Al and Fe to form a second phase to avoid excessive Mg causing a decrease in the mechanical properties and electrical conductivity of the aluminum alloy. In this way, the amount of Mg added in the present invention can be set to be greater than the amount of Mg added in the prior art, which not only breaks the technical prejudice in the prior art that excessive Mg addition affects the mechanical properties and electrical conductivity of the aluminum alloy, but also improves the mechanical properties, electrical conductivity and fatigue resistance of the aluminum alloy when more Mg is added, and can also avoid the cost increase caused by excessive addition of high-cost elements and the lack of targeted performance adjustment and process complexity caused by the addition of too many types of elements;

[0073] (4) The amount of Sn added can reach 0.3%, which is greater than the amount of Sn added in the prior art (the solid solubility of Sn in the aluminum matrix is extremely low, and excessive Sn will lead to an increase in β(Sn). β(Sn) is enriched in the grain boundaries during solidification and will reduce the mechanical properties of the aluminum alloy. Therefore, the amount of Sn added in the prior art is relatively small, usually not more than 0.08%). Sn will react with the remaining Mg to form a spherical dispersed Mg2Sn strengthening phase (Mg reacts first with Si to form Mg2Si phase, and then reacts with Sn. Sn will also promote the precipitation of Mg2Si phase), which can reduce Mg and the solid solubility of Sn in the aluminum matrix, thereby improving the electrical conductivity of the aluminum alloy. Sn will also react with Al to form various high-temperature strengthening phases such as Al9Sn7, Al6Sn5, Al5Sn2, and Al3Sn4, thereby improving the heat resistance and corrosion resistance of the aluminum alloy. In this way, the amount of Sn added in the present invention can be set to be greater than the amount of Sn added in the prior art. This not only breaks the technical prejudice in the prior art that excessive addition of Sn affects the mechanical properties of the aluminum alloy, but also improves the heat resistance, corrosion resistance, mechanical properties, and electrical conductivity of the aluminum alloy when more Sn is added.

[0074] (5) RE can refine the alloy structure to improve the mechanical properties of aluminum alloys. RE also forms a rare earth active film on the surface of the iron-containing phase or combines with Al, Fe, Ti and other atoms to form rare earth compounds, effectively reducing the solid solution of harmful element atoms in the aluminum matrix to improve the electrical conductivity and mechanical properties of aluminum alloys. RE can transform the long strip β-Fe phase into the spherical α-Fe phase and modify the elemental Si. RE can also promote dispersion precipitation, further improving the electrical conductivity and mechanical properties of aluminum alloys. In addition, RE can increase the recrystallization temperature of aluminum alloys, thereby improving the heat resistance, strength and plasticity of aluminum alloys.

[0075] (6) The amount of In added can reach 0.2%, which can be greater than the amount of In added in the prior art (excessive In will lead to a decrease in the mechanical properties of the aluminum alloy. Therefore, the amount of In added in the prior art is relatively small, usually not more than 0.1%). In can refine the grains, and In can also react with Al to produce AlIn high-temperature strengthening phase, and can react with Cu to generate CuIn high-temperature strengthening phase, which can greatly improve the mechanical properties of the aluminum alloy. The amount of Cu added is sufficient. In this way, the amount of In added in the present invention can be set to be greater than the amount of In added in the prior art. This not only breaks the technical prejudice in the prior art that the mechanical properties of the aluminum alloy are affected by excessive In addition, but also improves the mechanical properties of the aluminum alloy when more In is added.

[0076] The combined addition of In, Sn, and RE refines grains, stabilizes grain boundary phases, promotes the precipitation of strengthening phases, and improves the aluminum alloy's high-temperature strength, room-temperature strength, electrical conductivity, mechanical properties, plasticity, and heat resistance. Even when the amount of at least one of Mg, Si, Cu, In, and Sn added exceeds the amounts used in the prior art, the Al-Cu-RE rare earth aluminum alloy of the present invention still exhibits superior overall performance. The Al-Cu-RE rare earth aluminum alloy of the present invention contains secondary phases such as Mg2Si, Mg2Sn, Al9Sn7, Al6Sn5, Al5Sn2, Al3Sn4, Al2Cu, AlFeSi, AlFeMgSi, (CuMg)Al2, CuIn, and AlIn. Mg2Si, Mg2Sn, Al9Sn7, Al6Sn5, Al5Sn2, Al3Sn4, Al2Cu, CuIn, and AlIn are precipitation-strengthening phases, and AlFeSi, AlFeMgSi, and (CuMg)Al2 are grain-boundary strengthening phases. This allows the Al-Cu-RE rare earth aluminum alloy of the present invention to maintain excellent room-temperature strength, high-temperature strength, creep resistance, and structural stability while also having excellent electrical conductivity and fatigue resistance. Furthermore, under the action of In and RE, even if a large amount of Mg, Si, Cu, and In is added, the Al-Cu-RE rare earth aluminum alloy of the present invention can still exhibit excellent properties. In addition, since the addition amount of low-cost elements (such as Mg, Si, Cu, In, Sn, etc.) is increased and the aluminum alloy has good comprehensive properties, the addition of excessive expensive elements can be avoided, thereby reducing the cost of the Al-Cu-RE rare earth aluminum alloy of the present invention. In summary, the present invention uses only a small number of low-cost elements on the basis of maintaining low cost and low process complexity to obtain an Al-Cu-RE rare earth aluminum alloy for heat-resistant cables with excellent comprehensive properties (especially mechanical properties, heat resistance, corrosion resistance, and electrical conductivity).

[0077] The aluminum alloy may further contain at least one of Sb, Sr, Zn, B, Be, Bi, Mo, Cd, Fe, Ca, Ge, Zr, Sc and Co, so that the Al-Cu-RE series rare earth aluminum alloy has better comprehensive properties:

[0078] (1) The amount of Sb added can reach 0.5%, which can be greater than the amount of Sb added in the prior art (the solid solubility of Sb in the aluminum matrix is extremely low, and excessive Sb will reduce the mechanical properties and electrical conductivity of the aluminum alloy. Therefore, the amount of Sb added in the prior art is relatively small, usually not more than 0.3%). Sb will react with the remaining Mg (Mg reacts with Si first, and then with Sb) to form a rounded spherical dispersed Mg3Sb2 strengthening phase, which can reduce the solid solubility of Mg and Sb in the aluminum matrix, thereby improving the electrical conductivity and mechanical properties of the aluminum alloy. In this way, the amount of Sb added in the present invention can be set to be greater than the amount of Sb added in the prior art, which not only breaks the technical prejudice in the prior art that the mechanical properties and electrical conductivity of the aluminum alloy are affected by excessive addition of Sb, but also improves the mechanical properties and electrical conductivity of the aluminum alloy when more Sb is added;

[0079] (2) Sr can promote the precipitation of precipitated phases and is also a modifier in aluminum alloys. During the subsequent nucleation process, it is adsorbed on the surface of the Si phase, inhibiting the growth of the Si phase to improve the hot deformation process performance of the aluminum alloy, significantly improving the mechanical properties, plasticity and electrical conductivity of the aluminum alloy;

[0080] (3) The amount of Zn added can reach 0.3%, which is greater than the amount of Zn added in the prior art (a small amount of Zn has little effect on the electrical conductivity and mechanical properties of the aluminum alloy. The amount of Zn added in the prior art is usually not more than 0.04%, otherwise it will seriously affect the corrosion resistance, electrical conductivity and mechanical properties of the aluminum alloy). By setting the amount of Zn added to be greater than the amount of Zn added in the prior art, on the one hand, Zn can be used to promote the precipitation of precipitated phases such as Mg2Si and Al2Cu, and eliminate Si element. On the other hand, under the action of stress, Zn can form MgZn2 phase with Mg, which plays a precipitation strengthening role. Zn will also form CaZn and CaAlZn with Al and Ca, so that the aluminum alloy obtains superplasticity. In this way, the amount of Zn added in the present invention can be set to be greater than the amount of Zn added in the prior art, which not only breaks the technical prejudice in the prior art that excessive addition of Zn affects the corrosion resistance, electrical conductivity and mechanical properties of the aluminum alloy, but also improves the mechanical properties and electrical conductivity of the aluminum alloy when more Zn is added;

[0081] (4) Fe can react with Al and Si to form α-Fe2SiAl8 (or Fe3Si2Al 12 ), to avoid the formation of coarse β-FeSiAl3 (or Fe2Si2Al9) phase, α-Fe2SiAl8 (or Fe3Si2Al 12 ) is a cubic structure, which is beneficial to improve the mechanical properties of aluminum alloys. Co can promote the formation of spherical Fe phase. When the addition amount of Co is 0-0.8%, Al3(Fe,Co) phase with smaller particle size can be generated to improve the mechanical properties of aluminum alloys. The generated Al3Fe phase can also be converted into α-Al15 (Fe, Co) 3 Si 2 (which can be in the form of granules, small flowers, or thin strips) and has a refining effect on the Al 3 Fe phase, further improving the mechanical properties, heat resistance, and plasticity of the aluminum alloy. The present invention sets the mass ratio of Fe to Si to 1:0.1-5, which can ensure that Si fully reacts with Fe and avoids the adverse effect of excessive Si on the electrical conductivity of the aluminum alloy;

[0082] (5) The amount of Cd added can reach 0.3%, which can be greater than the amount of Cd added in the prior art (the amount of Cd added in the prior art is usually not more than 0.1%, otherwise the Cd element will remain in the intergranular form in the form of Cd-rich phase, reducing the plasticity of the aluminum alloy). Cd can refine α-Al and react with Al, Fe and RE in the melt to form various metal compounds such as REAl2Cd3, Fe3Al2Cd, Al3Cd, and Al2Cd3, which can improve the tensile properties of the aluminum alloy. Cd will form a large number of Cd-vacancy clusters in the aging stage, promoting and accelerating the precipitation of CuAl2, Mg3Sb2, Mg3Bi2, Mg2Si, and Mg2Sn phases. Moreover, a large amount of CuAl2 phase precipitates under the action of Cd and RE. When the amount of Cd added is large, sufficient Cd provides nucleation sites for the CuAl2 phase to form (CuCd)Al2, Mg2(SiCdREFe), Mg2(SnCd), Mg3(BiCd)2, AlCuCdMgNi and other strengthening phases are formed, thereby improving the mechanical properties of the aluminum alloy. In addition, a small amount of Cd dispersed in the aluminum matrix can greatly improve the toughness and plasticity of the aluminum alloy. The amount of Cd added is set to be greater than the amount of Cd added in the prior art. On the one hand, it is beneficial for Cd to improve the toughness of the aluminum alloy. On the other hand, Cd reacts with Al, Cu, Sn, Si, Fe and RE to form compounds to avoid excessive Cd causing a decrease in the plasticity of the aluminum alloy. In this way, the amount of Cd added in the present invention can be set to be greater than the amount of Cd added in the prior art, which not only breaks the technical prejudice in the prior art that the conductive properties of the aluminum alloy are affected by excessive addition of Cd, but on the contrary, when more Cd is added, the toughness, plasticity, mechanical properties and tensile properties of the aluminum alloy are simultaneously improved.

[0083] (6) The amount of Mo added can reach 0.3%, which can be greater than the amount of Mo added in the prior art (the amount of Mo added in the prior art is usually not greater than 0.1%, otherwise the electrical conductivity of the aluminum alloy will be reduced). Mo can refine the grains, and Mo can form an AlMo high-temperature strengthening phase with Al to improve the mechanical properties of the aluminum alloy. It can also form a Mo(AlSi)2 phase with Al and Si to improve the corrosion resistance of the aluminum alloy. The amount of Si added is sufficient. In this way, the amount of Mo added in the present invention can be set to be greater than the amount of Mo added in the prior art. This not only breaks the technical prejudice in the prior art that the electrical conductivity of the aluminum alloy is affected by excessive addition of Mo, but also improves the mechanical properties and corrosion resistance of the aluminum alloy when more Mo is added.

[0084] (7) The amount of Sc added can reach 0.3%, which can be greater than the amount of Sc added in the prior art (excessive Sc will lead to excessively large grain size, therefore, the amount of Sc added in the prior art is relatively small, usually not more than 0.15%). Sc can react with Al to form Al3Sc particles, which can significantly refine the alloy structure, change the size, shape and distribution of the strengthened η phase, and thus improve the mechanical properties, plasticity and high-temperature stability of the aluminum alloy. Sc can also react with Al, Sc and Cu to form AlScCu, Mg2ScSi, Mg2ScSn, Al3ScZr phases, thereby improving the mechanical properties of the aluminum alloy. The amount of Cu added is sufficient, so the amount of Sc added in the present invention can be set to be greater than the amount of Sc added in the prior art. This not only breaks the technical prejudice in the prior art that the mechanical properties of the aluminum alloy are affected by excessive addition of Sc, but also improves the heat resistance, corrosion resistance, mechanical properties, and electrical conductivity of the aluminum alloy when more Sc is added.

[0085] (8) The amount of Zr added can reach 0.3%, which is greater than the amount of Zr added in the prior art (the amount of Zr added in the prior art is usually not more than 0.1%, otherwise the electrical conductivity of the aluminum alloy will drop sharply). Zr can synergize with RE to inhibit the recrystallization of the alloy. Zr can also form (Zr, RE)Al3 compounds with rare earth elements such as Er, which promotes the precipitation of β″ phase and makes the β″ phase finer and more dispersed, which can increase the recrystallization temperature and heat resistance of the aluminum alloy. Zr will also promote the precipitation of Mg2Sn, further reducing the concentration of Mg and Sn in the aluminum matrix. The solid solubility of Zr in the present invention is set to be greater than the amount of Zr added in the prior art. On the one hand, Zr is beneficial to improving the mechanical properties and plasticity of the aluminum alloy. On the other hand, Zr reacts with rare earth to form compounds to avoid excessive Zr causing a decrease in the electrical conductivity of the aluminum alloy. In this way, the amount of Zr added in the present invention can be set to be greater than the amount of Zr added in the prior art. This not only breaks the technical prejudice in the prior art that excessive Zr addition affects the electrical conductivity of the aluminum alloy, but also improves the mechanical properties and electrical conductivity of the aluminum alloy when more Zr is added.

[0086] (9) The amount of B added can reach 0.1%, which is greater than the amount of B added in the prior art (too much B will increase the size of the iron-containing phase, causing the aggregation of B grains and reducing the refinement effect, and will also react with strengthening elements to reduce the mechanical properties of the aluminum alloy. In the prior art, the amount of B added is usually not more than 0.05%). The amount of B added is set to be greater than the amount of B added in the prior art. In this way, B can not only undergo boriding with transition metal impurity elements such as Ti, Cr, and Zr to improve the electrical conductivity of the aluminum alloy (this can avoid the influence of excessive Zr addition on the electrical conductivity of the aluminum alloy), but also has a refining effect, improving the mechanical properties and room temperature strength of the aluminum alloy. B can also react with Fe, Al, and Si to form a complex multi-component compound, which can not only further eliminate elemental Si, but also change the morphology of the iron phase (from needle-like to short flake-like, polyhedral, or Chinese character-like) to improve the mechanical properties and electrical conductivity. In this way, the amount of B added in the present invention can be set to be greater than the amount of B added in the prior art, which not only breaks the technical prejudice in the prior art that excessive B addition affects the mechanical properties of the aluminum alloy, but also improves the room temperature strength, mechanical properties, and electrical conductivity of the aluminum alloy when more B is added.

[0087] (10) Be can promote the precipitation of Mg2Si, Mg3Bi2, and Mg2Sn phases, reduce Mg loss, avoid casting defects, and reduce the generation of oxide impurities. It can also promote the transformation of the plate-like β intermediate phase into the relatively harmless Chinese character-shaped Be-Fe (Al8Fe2SiBe) phase, and transform the eutectic Si phase from a lamellar phase to a fine phase, thereby increasing the recrystallization temperature of the aluminum alloy and reducing the recrystallization rate of the aluminum alloy, thereby improving the mechanical properties, high temperature strength, room temperature strength, and plasticity of the aluminum alloy;

[0088] (11) The amount of Ge added can reach 0.3%, which is greater than the amount of Ge added in the prior art (lower content of Ge has little effect on the electrical conductivity and mechanical properties of aluminum alloys, while higher content of Ge will reduce the electrical conductivity and mechanical properties of aluminum alloys. Therefore, the amount of Ge added in the prior art is usually not greater than 0.2%). Ge has a strong binding ability with the quenching vacancies in the α-Al matrix, and is easy to capture the quenching vacancies in the α-Al matrix and form "Ge-vacancy pairs". Ge can form A in the melt. l9High-temperature strengthening phases such as Ge7, Al6Ge5, Al5Ge2, and Al3Ge4 improve the heat resistance of the aluminum alloy. Ge can also refine the precipitated phase, promote the precipitation of the precipitated phase (such as Mg2Si and CuAl2, etc.), and replace some Si atoms in the metastable precipitated phase. The Si-Ge phase precipitated at the early stage of aging provides a nucleation site for the θ phase, increasing the density of the θ phase. The addition amount of Si can reach 0.5%, which can react with a large amount of Ge to form a Si-Ge phase and provide a nucleation site for the θ phase, thereby improving the mechanical properties and electrical conductivity of the aluminum alloy. In this way, the addition amount of Ge in the present invention can be set to be greater than the addition amount of Ge in the prior art, which not only breaks the technical prejudice in the prior art that the electrical conductivity and mechanical properties of the aluminum alloy are affected by excessive addition of Ge, but also improves the heat resistance, electrical conductivity and mechanical properties of the aluminum alloy when more Ge is added.

[0089] (12) Bi expands during the solidification process, which is beneficial for shrinkage compensation and can also prevent sodium embrittlement. It can form Mg3Bi2 strengthening phase with Mg, thereby improving the mechanical properties of aluminum alloys. Ca can refine the eutectic structure and improve the β-Fe phase, thereby improving the heat treatment properties of the alloy while increasing the strength of the alloy. It can also form Al4Ca, Al2Ca3, AlCa2, and AlCaCu strengthening phases with Cu and Al, significantly improving the strength, heat resistance, and fatigue resistance of aluminum alloys.

[0090] The composite addition of at least two of Zr, RE, Be, Sn, Ge, Cd, Zn, and Sr promotes the precipitation of strengthening phases such as Mg2Si, Mg3Sb2, Mg3Bi2, Mg2Sn, (CuMg)Al2, and CuAl2; the composite addition of at least two of Zr, RE, Be, B, Sc, Mo, In, Sr, Cd, and Ca refines the grains and replaces the Ti element that causes a sharp drop in electrical conductivity; the composite addition of at least two of Zr, RE, and Be stabilizes the grain boundary phase and improves the high-temperature strength, room-temperature strength, and heat resistance of the aluminum alloy; the composite addition of at least two of Sc, B, Co, RE, and Ca improves the β-Fe phase and transforms the long β-Fe The phase is transformed into a spherical α-Fe phase and the elemental Si is modified; the composite of B and Sr can modify the aluminum matrix and Mg2Si phase, so that the distribution of elements such as Ti, V, Cr to the grain boundaries is reduced, and they react with each other to form massive borides, so that the solid solution elements such as Ti, V, Cr are transformed into precipitation states, which weakens the lattice distortion of Al and increases the electrical conductivity; the addition amount of at least one of Mg, Si, Cu, Sc, In, Zr, Ge, Sn, Sb, B, Cd and Zn is set to be greater than the addition amount of Mg, Si, Cu, Sc, In, Zr, Ge, Sn, Sb, B, Cd and Zn in the prior art, so as to avoid adding too many expensive elements and obtain A l9A lMo, CuIn, AlIn, AlScCu, Mg2ScSi, Mg2ScSn, Mg3(ScBi)2, Mg3(ScSb)2, Mg3Bi2, MgZn2, CaZn, CaAlZn, AlCaCu, Al9Sn7, Al6Sn5, Al5Sn2, Al3Sn4, α-Al 15 (Fe,Co)3Si2, Al3(Fe,Co), Mg2Sn, Mg3Sb2, Mg2Si, Al2Cu, Al3(Zr,RE), AlFeMgSiNi, FeNiAl9, AlFeSi, Second phases such as AlFeMgSi, (CuMg)Al2, AlFeSiNi, Be-Fe(Al8Fe2SiBe), Al4Ca, Al2Ca3, AlCa2, AlCaCu, Al3ScZr, A l9 Ge7, Al6Ge5, Al5Ge2, Al3Ge4, Al3Cd, Al2Cd3, AlMo, CuIn, AlIn, Al3Sc, Mg3Bi2, MgZn2, CaZn, Al9Sn7, Al6Sn5, Al5Sn2, Al3Sn4, Mg2Sn, AlCaCu, Mg3Sb2, Mg2Si, Al2Cu, Al4Ca, Al2Ca3, AlCa2, etc. are precipitation strengthening phases, (CuCd)Al2, Mg2(SiCdREFe), Mg2(SnCd), Mg3(BiCd)2, AlCuCdMgNi, Mo(AlSi)2, AlScCu, Mg2ScSi, Mg2ScSn, Mg3(ScBi)2, Mg3(ScSb)2, REAl2Cd3, Fe3Al2Cd, α-Al 15 (Fe,Co)3Si2, Al3(Fe,Co), Al3(Zr,RE), AlFeMgSiNi, FeNiAl9, AlFeSi, AlFeMgSi, (CuMg)Al2, AlFeSiNi, Be-Fe(Al8Fe2SiBe), CaAlZn, AlCaCu, Al3ScZr, etc. are grain boundary strengthening phases, which make Al-Cu-RE rare earth aluminum alloys have better comprehensive properties, especially mechanical properties, heat resistance, corrosion resistance, and electrical conductivity.

[0091] The present invention also provides a method for preparing an Al-Cu-RE series rare earth aluminum alloy, comprising the following steps:

[0092] Melting: Heat the aluminum source (such as aluminum ingot) to 720-780℃ to obtain aluminum liquid. Add Cu, Mg, Si, RE, In, and Sn to the aluminum liquid and heat and melt it. After stirring evenly, refine it, degas and skim off the slag. After standing and keeping it at 700-750℃ for 10-30 minutes, after obtaining the alloy liquid, keep it warm and stand it for composition and content detection.

[0093] Continuous casting and rolling: After the composition and content are tested to be qualified, the alloy liquid after degassing and slagging treatment is continuously cast and rolled to obtain aluminum alloy rods;

[0094] Drawing treatment: drawing the aluminum alloy rod to obtain an aluminum alloy wire;

[0095] Twisting process: Twisting aluminum alloy wire with high elastic wire to form aluminum alloy conductor; and

[0096] Aging treatment: The aluminum alloy conductor is subjected to aging treatment and cooled to obtain the Al-Cu-RE rare earth aluminum alloy. The Al-Cu-RE rare earth aluminum alloy contains 0.01-0.6% by mass of Cu, 0.001-0.2% by mass of RE, 0-0.7% by mass of Mg, 0-0.3% by mass of Si, 0-0.2% by mass of In, 0-0.3% by mass of Sn, Al, and unavoidable impurities.

[0097] It is understood that when the content of each component in the alloy liquid after degassing and slag removal meets the standards, subsequent processing such as continuous casting and rolling can be carried out. The aluminum alloy contains 0.01-0.6% Cu by weight, 0.001-0.2% RE by weight, 0-0.7% Mg by weight, 0-0.3% Si by weight, 0-0.2% In by weight, 0-0.3% Sn by weight, and Al and unavoidable impurities. If the composition and content tests fail, the corresponding elements can be added to adjust the composition and content until they pass.

[0098] In one embodiment, the mass percentage content of Cu may be 0.01%, 0.05%, 0.1%, 0.15%, 0.2%, 0.25%, 0.3%, 0.31%, 0.32%, 0.33%, 0.34%, 0.35%, 0.4%, 0.45%, 0.5%, 0.55%, or 0.6%; the mass percentage content of Mg may be 0.01%, 0.05%, 0.1%, 0.15%, 0.2%, 0.25%, 0.3%, 0.31%, 0.32%, 0.33%, 0.34%, 0.35%, 0.4%, 0.45%, 0.5%, 0.55%, or 0.6%. 33%, 0.34%, 0.35%, 0.4%, 0.45%, 0.5%, 0.55%, 0.6%, 0.65%, or 0.7%; the mass percentage content of Si can be specifically 0.001%, 0.005%, 0.01%, 0.05%, 0.1%, 0.15%, 0.2%, 0.21%, 0.25%, or 0.3%; the mass percentage content of RE can be specifically 0.001%, 0.005%, 0.01%, 0.02%, 0.03%, 0.04%, 0.05%. %, 0.06%, 0.07%, 0.08%, 0.09%, 0.1%, 0.11%, 0.12%, 0.13%, 0.14%, 0.15%, 0.16%, 0.17%, 0.18%, 0.19%, or 0.2%; the mass percentage content of In can be 0.001%, 0.005%, 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.1%, 0.11%, 0. The mass percentage content of Sn can be 0.001%, 0.005%, 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.1%, 0.11%, 0.12%, 0.13%, 0.14%, 0.15%, 0.2%, 0.25%, or 0.3%.

[0099] The mass ratio of Mg, Sn, and Si is 1-20:0.5-5:1. Specifically, the mass ratio of Mg, Sn, and Si is 1:0.5:1, 1:1:1, 1:1.5:1, 1:2:1, 1:2.5:1, 1:3:1, 1:4:1, 1:4.5:1, 1:5:1, 5:0.5:1, 5:1:1, 5:1.5:1, 5:2:1, 5:2.5:1, 5:3:1, 5:4:1, 5:4.5:1, 5:5:1, 10:0.5:1, 10:1:1, 10:1.5:1, 10:2:1, 10:2 .5:1, 10:3:1, 10:4:1, 10:4.5:1, 10:5:1, 15:0.5:1, 15:1:1, 15:1.5:1, 15:2:1, 15:2.5:1, 15:3:1, 15:4:1, 15:4.5:1, 15:5:1, 20:0.5:1, 20:1:1, 20:1.5:1, 20:2:1, 20:2.5:1, 20:3:1, 20:4:1, 20:4.5:1, or 20:5:1.

[0100] The mass ratio of Mg to Si is 0.2-40:1. Specifically, the mass ratio of Mg to Si is 0.2:1, 0.5:1, 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, 11:1, 12:1, 13:1, 14:1, 15:1, 16:1, 17:1, 18:1, 19:1, 20:1, 30:1, or 40:1. Within this mass ratio range, as the mass ratio of Mg to Si increases, the conductive strength gradually increases.

[0101] The mass ratio of Cu to Si can be 0.5-30:1. Specifically, the mass ratio of Cu to Si is 0.5:1, 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, 11:1, 12:1, 13:1, 14:1, 15:1, 16:1, 17:1, 18:1, 19:1, 20:1, 25:1, 30:1, 35:1, or 40:1. Within this mass ratio range, as the Cu / Si mass ratio increases, the tensile strength gradually increases.

[0102] The mass ratio of Mg to In is 0.3-40:1. Specifically, the mass ratio of Mg to In is 0.3:1, 0.5:1, 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, 11:1, 12:1, 13:1, 14:1, 15:1, 16:1, 17:1, 18:1, 19:1, 20:1, 25:1, 30:1, 35:1, or 40:1. Within this mass ratio range, as the Mg / In mass ratio increases, the conductive strength gradually increases.

[0103] The mass ratio of Cu to In is 0.3-40:1. Specifically, the mass ratio of Cu to In is 0.3:1, 0.5:1, 1:

[0104] 1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, 11:1, 12:1, 13:1, 14:1, 15:1, 16:1, 17:1, 18:1, 19:1, 20:1, 25:1, 30:1, 35:1, or 40: 1. Within this mass ratio range, as the mass ratio of Cu / In increases, the tensile strength gradually increases.

[0105] RE is at least one of La, Ce, Pr, Nd, Er, Sm, Y, and Gd.

[0106] The mass percentage content of the impurities is no more than 0.15%, and the mass percentage content of a single impurity is less than 0.05%.

[0107] In one embodiment, the casting temperature is 680-750°C, and the rolling temperature is 450-550°C.

[0108] In one embodiment, the drawing process may be cold drawing. During cold drawing, the aluminum alloy rod is drawn into an aluminum alloy wire within a predetermined diameter range. The elongation coefficient of each cold drawing pass is controlled to be 0.5-2. After each cold drawing pass, the temperature is raised to 250-350°C and maintained at this temperature for 5-20 hours, followed by a secondary heat treatment to obtain the aluminum alloy wire.

[0109] In one embodiment, the aging treatment is a bipolar aging treatment, comprising the following steps: a low-temperature aging treatment at a temperature of 100-150°C for 1-150 hours; and a high-temperature aging treatment at a temperature of 150-250°C for 1-100 hours. The bipolar aging treatment maximizes the precipitation of dissolved elements in the aluminum alloy, thereby improving the mechanical properties and electrical conductivity of the aluminum alloy. The high-temperature aging treatment temperature may be higher than that of the low-temperature aging treatment. The low-temperature aging treatment temperature may be 100°C, 110°C, 120°C, 130°C, 140°C, or 150°C. The high-temperature aging treatment temperature may be 150°C, 160°C, 170°C, 180°C, 190°C, 200°C, 210°C, 220°C, 230°C, 240°C, or 250°C. The time for low-temperature aging treatment may be 1 hour, 10 hours, 20 hours, 30 hours, 40 hours, 50 hours, 60 hours, 70 hours, 80 hours, 90 hours, 100 hours, 110 hours, 120 hours, 130 hours, 140 hours, or 150 hours. The time for high-temperature aging treatment may be 1 hour, 10 hours, 20 hours, 30 hours, 40 hours, 50 hours, 60 hours, 70 hours, 80 hours, 90 hours, or 100 hours. The time for high-temperature aging treatment may not be longer than the time for low-temperature aging treatment. The temperature for high-temperature aging treatment may be 1.2-2.5 times, preferably 1.5-2 times, of the temperature for low-temperature aging treatment. The time for low-temperature aging treatment may be 1.1-50 times, preferably 5-40 times, and preferably 10-20 times, of the time for high-temperature aging treatment.

[0110] In one embodiment, the refining process temperature is 690-750°C for 10-20 minutes. The refining agent for the refining process may include the following raw materials in parts by weight: 60-70 parts KF, 50-60 parts NaCl, 40-60 parts LiCl, 20-25 parts cryolite, 10-25 parts AIF3, 10-15 parts CaF2, 5-10 parts light calcium carbonate, 15-20 parts graphite powder, 10-20 parts talc, 20-30 parts MgCl2, and 10-30 parts rare earth salt. The rare earth salt may be a combination of one or more of a light rare earth chloride, fluoride, or nitric acid compound. The rare earth salt may be a combination of one or more of a heavy rare earth chloride, fluoride, or nitric acid compound. The mass ratio of the refining agent to the alloy solution is 0.0013-0.0018:1.

[0111] In one embodiment, at least one of Sb, Sr, Sc, Zn, B, Be, Bi, Mo, Cd, Fe, Ca, Ge, Zr, and Co may be added to the aluminum liquid.

[0112] In one embodiment, Cu, Mg, Si, RE, In, Sc, Sb, Sr, Zn, B, Be, Bi, Mo, Cd, Fe, Ca, Ge, Zr, and Co are added in the form of single elements and / or aluminum master alloys.

[0113] The mass percentage content of Sb may be 0-0.5%. The mass percentage content of Sr may be 0-0.2%. The mass percentage content of Sc may be 0-0.3%. The mass percentage content of Zn may be 0-0.3%. The mass percentage content of B may be 0-0.1%. The mass percentage content of Be may be 0-0.1%. The mass percentage content of Bi may be 0-0.3%. The mass percentage content of Mo may be 0-0.3%. The mass percentage content of Cd may be 0-0.3%. The mass percentage content of Co may be 0-0.8%. The mass percentage content of Ca may be 0-0.5%. The mass percentage content of Ge may be 0-0.3%. The mass percentage content of Zr may be 0-0.3%. The mass percentage content of Fe may be 0-0.3%.

[0114] The mass ratio of Mg to Fe may be 0.2-20:1, specifically 0.2:1, 0.5:1, 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, 11:1, 12:1, 13:1, 14:1, 15:1, 16:1, 17:1, 18:1, 19:1, or 20:1.

[0115] The mass ratio of Sc to Fe can be 0.1-10:1, specifically 0.1:1, 0.2:1, 0.5:1, 1:1, 2:

[0116] 1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, or 10:1.

[0117] The mass ratio of Si to Fe may be 0.1-5:1, specifically 0.1:1, 0.15:1, 0.2:1, 0.25:1, 0.3:1, 0.4:1, 0.5:1, 0.6:1, 0.7:1, 0.8:1, 0.9:1, 1:1, 2:1, 3:1, 4:1, or 5:1.

[0118] The mass ratio of Mg to Sc is 0.1-20:1. Specifically, the mass ratio of Mg to Sc is 0.1:1, 0.2:1, 0.5:1, 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, 11:1, 12:1, 13:1, 14:1, 15:1, 16:1, 17:1, 18:1, 19:1, or 20:1. Within this mass ratio range, as the mass ratio of Mg to Sc increases, the conductive strength gradually increases.

[0119] The mass ratio of Cu to Sc can be 1-30:1. Specifically, the mass ratio of Cu to Sc is 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, 11:1, 12:1, 13:1, 14:1, 15:1, 16:1, 17:1, 18:1, 19:1, 20:1, 25:1, or 30:1. Within this mass ratio range, as the Cu / Sc mass ratio increases, the tensile strength gradually increases.

[0120] The mass ratio of Sc to Zr is 0.5-2.5:1. Specifically, it can be 0.5:1, 0.6:1, 0.7:1, 0.8:1, 0.9:1, 1.1:1, 1.2:1, 1.3:1, 1.4:1, 1.5:1, 2:1, or 2.5:1.

[0121] The mass ratio of In to B is 0.1-10:1, for example, 0.1:1, 0.5:1, 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, or 10:1.

[0122] The mass ratio of Sc, In, and B is 0.1-15:0.1-10:1, preferably 1-10:1-5:1. The mass ratio of Sc, In, and B can specifically be 0.1:0.1:1, 0.5:0.1:1, 1:0.1:1, 5:0.1:1, 10:0.1:1, 15:0.1:1, 0.1:1:1, 0.5:1:1, 1:1:1, 5:1:1, 10:1:1, 15:1:1, 0.1:5:1, 0.5:5:1, 1:5:1, 5:5:1, 10:5:1, 15:5:1, 0.1:10:1, 0.5:10:1, 1:10:1, 5:10:1, 10:10:1, or 15:10:1.

[0123] In the technical solution of the present invention, Cu, Mg, Si, RE, Sn, and In are added to molten aluminum, heated and smelted, and then continuously cast and rolled, drawn, stranded, and aged to obtain an Al-Cu-RE rare earth aluminum alloy. The Al-Cu-RE rare earth aluminum alloy contains 0.01-0.6% Cu by weight, 0.001-0.2% RE by weight, 0-0.7% Mg by weight, 0-0.3% Si by weight, 0-0.2% In by weight, and 0-0.3% Sn by weight. When these elements are added individually to an aluminum matrix, the improvement in the electrical conductivity and mechanical properties of the aluminum is limited, and may even have a negative effect on the electrical conductivity and mechanical properties of the aluminum. The present invention adds these elements to the aluminum matrix together, and the interaction between these elements can reduce each other's solid solubility in the aluminum matrix, thereby reducing the adverse effects of certain elements on electrical conductivity and improving electrical conductivity. The elements will also dissolve into other precipitated phases and second phases to form strengthening phases, thereby significantly improving the overall performance of the aluminum alloy. The Al-Cu-RE rare earth aluminum alloy uses a small number of elements and is inexpensive. Although RE and Sc are slightly more expensive, their use is small and has little impact on the cost of the Al-Cu-RE rare earth aluminum alloy. In addition, RE and Sc have mechanical properties and electrical conductivity that cannot be matched by other elements. The mutual cooperation of the elements can also promote the precipitation volume fraction of the strengthening phase to reduce the total amount of elements added to the aluminum matrix. Generally, in soft heat-resistant cables, the amount of alloying elements added is inversely proportional to the electrical conductivity and elongation, and directly proportional to the tensile strength and yield strength. In the soft state, to ensure that the electrical conductivity reaches the national standard value (greater than 61% IACS), the total amount of elements added to the cable aluminum alloy does not exceed 1.0 wt%. To ensure that the tensile strength is greater than 185 MPa, the total amount of elements added to the cable aluminum alloy generally exceeds 1.0 wt%. However, the electrical conductivity will definitely be lower than the national standard value (greater than 61% IACS). However, the present invention achieves better comprehensive performance (specifically, the tensile strength of the Al-Cu-RE rare earth aluminum alloy is greater than that of the hard alloy, the elongation of the Al-Cu-RE rare earth aluminum alloy is greater than that of the soft alloy, and the electrical conductivity is greater than 61% IACS) when the total amount of elements added to the aluminum alloy is less than 1.0 wt% while ensuring mechanical properties and electrical conductivity. This further reduces the cost of the Al-Cu-RE rare earth aluminum alloy. In summary, the present invention can obtain Al-Cu-RE rare earth aluminum alloy for heat-resistant cables with excellent comprehensive properties (especially mechanical properties, heat resistance, corrosion resistance, and electrical conductivity) by using only a small number of low-priced elements while maintaining low cost and low process complexity.

[0124] The present invention also provides a heat-resistant cable comprising a core and an insulation layer covering the core, wherein the core is made of the Al-Cu-RE rare earth aluminum alloy. The heat-resistant cable may further include other components. In one embodiment, the heat-resistant cable may further include an inner shielding layer disposed between the core and the insulation layer, an outer shielding layer covering the insulation layer, and a protective layer covering the core and the outer shielding layer.

[0125] Since the heat-resistant cable adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought by the technical solutions of the above embodiments, which will not be described one by one here.

[0126] Examples and Comparative Examples

[0127] The components and contents of the aluminum alloys of Examples 1 to 7 and Comparative Examples 1 to 4 are shown in Table 1, and the performance test results are shown in Table 2.

[0128] Table 1 Composition and content of aluminum alloys of Examples 1 to 7 and Comparative Examples 1 to 4

[0129]

[0130]

[0131] To simplify the description, the contents of trace elements such as impurities are not shown in the comparative examples and examples.

[0132] The electrical conductivity of the aluminum alloys of Examples 1 to 7 and Comparative Examples 1 to 4 was tested using a QJ57 digital DC bridge meter manufactured by Shanghai Zhengyuan Electrical Technology Co., Ltd. The specimens were 2.5 mm x 1000 mm in diameter. During the test, the temperature was controlled at 20 ± 0.1°C. Three specimens were tested under the same conditions, and the average value was calculated.

[0133] At room temperature, the mechanical properties of the aluminum alloys of Examples 1 to 7 and Comparative Examples 1 to 4 were tested using a domestically produced CSS-44100 electronic universal tensile tester in accordance with the test requirements of GB4909, "Bare Wire Tensile Test." The tensile force of the electronic universal tensile tester was 2 kN, and the tensile speed was 2 mm / min. Three specimens were tested under the same conditions, and the average value was calculated.

[0134] The heat resistance (strength retention) of the aluminum alloys of Examples 1 to 7 and Comparative Examples 1 to 4 was tested using a domestically produced JCT-1 electric high-temperature drying oven with a temperature fluctuation of ±1°C. The annealing temperature was 230°C, the holding time was 1 hour, and three samples were tested under the same conditions, with the average value taken.

[0135] Table 2 Performance test results of aluminum alloys of Examples 1 to 7 and Comparative Examples 1 to 4

[0136]

[0137]

[0138] The tensile strength, elongation, electrical conductivity, and heat resistance of the Al-Cu-RE rare earth aluminum alloys of Examples 1 to 7 are significantly greater than those of the Al-Cu-RE rare earth aluminum alloys of Comparative Examples 1 to 4. This demonstrates that the Al-Cu-RE rare earth aluminum alloys of the present invention exhibit superior properties.

[0139] The above description is only a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformation made by using the contents of the present invention specification under the inventive concept of the present invention, or direct / indirect application in other related technical fields, is included in the patent protection scope of the present invention.

Claims

1. An Al-Cu-RE rare earth aluminum alloy containing Al, characterized in that: The Al-Cu-RE rare earth aluminum alloy also contains 0.01-0.6% Cu by mass, 0.001-0.2% RE by mass, 0-0.7% Mg by mass, 0-0.3% Si by mass, 0-0.2% In by mass, 0-0.1% B by mass, 0-0.3% Mo by mass, and 0-0.3% Sn by mass.

2. The Al-Cu-RE rare earth aluminum alloy according to claim 1, characterized in that: The Al-Cu-RE rare earth aluminum alloy also contains 0.01-0.6% Cu by mass, 0.001-0.2% RE by mass, 0.01-0.7% Mg by mass, 0.001-0.3% Si by mass, 0.001-0.2% In by mass, 0.001-0.1% B by mass, 0.001-0.3% Mo by mass, and 0.001-0.3% Sn by mass.

3. The Al-Cu-RE rare earth aluminum alloy according to claim 1, characterized in that: The mass ratio of In to B is 0.1-10:

1.

4. The Al-Cu-RE rare earth aluminum alloy according to claim 1, wherein: Meet at least one of the following conditions: The mass ratio of Mg to Si is 0.2-40:1; The mass ratio of Cu to Si is 0.5-30:1; The mass ratio of Mg to In is 0.3-40:1; The mass ratio of Cu to In is 0.3-40:1; The mass ratio of Mg, Sn, and Si is 1-20:0.5-5:1; RE is at least one of La, Ce, Pr, Nd, Er, Sm, Y, and Gd.

5. The Al-Cu-RE rare earth aluminum alloy according to claim 1, characterized in that: Meet at least one of the following conditions: The Al-Cu-RE series rare earth aluminum alloy further contains Sb in an amount of 0-0.5% by mass; The Al-Cu-RE series rare earth aluminum alloy further contains Sr in a mass percentage content of 0-0.2%; The Al-Cu-RE series rare earth aluminum alloy further contains Bi in a mass percentage content of 0-0.3%; The Al-Cu-RE series rare earth aluminum alloy further contains Ca in a mass percentage content of 0-0.5%; The Al-Cu-RE series rare earth aluminum alloy further contains Ge in a mass percentage content of 0-0.3%.

6. The Al-Cu-RE rare earth aluminum alloy according to any one of claims 1 to 5, characterized in that: The Al-Cu-RE series rare earth aluminum alloy further contains 0-0.3% by mass of Fe, wherein the mass ratio of Mg to Fe is 0.2-20:1, and the mass ratio of Si to Fe is 0.1-5:

1.

7. The Al-Cu-RE rare earth aluminum alloy according to claim 6, characterized in that: The mass percentage content of Fe is 0.001-0..25%.

8. A method for preparing the Al-Cu-RE rare earth aluminum alloy according to any one of claims 1 to 7, comprising the following steps: The aluminum source is subjected to a first heating treatment to obtain aluminum liquid; adding Cu, Mg, Si, RE, In, B, Mo, and Sn to the aluminum liquid and performing a second heating treatment to obtain an alloy liquid; The alloy liquid is subjected to refining and slag removal treatments, and composition and content testing is performed; After the composition and content are tested to be qualified, the alloy liquid after the refining and slagging treatment is subjected to continuous casting, continuous rolling and drawing to obtain aluminum alloy wire; and An aluminum alloy wire is subjected to aging treatment to obtain an Al-Cu-RE series rare earth aluminum alloy, wherein the Al-Cu-RE series rare earth aluminum alloy contains Al, 0.01-0.6% by mass of Cu, 0.001-0.2% by mass of RE, 0-0.7% by mass of Mg, 0-0.3% by mass of Si, 0-0.2% by mass of In, 0-0.1% by mass of B, 0-0.3% by mass of Mo, and 0-0.3% by mass of Sn.

9. The method for preparing the Al-Cu-RE rare earth aluminum alloy according to claim 8, wherein: Meet at least one of the following conditions: The preparation method of the Al-Cu-RE series rare earth aluminum alloy further includes the step of adding at least one of Sb, Sr, Bi, Fe, Ca, and Ge to the aluminum liquid; The aging treatment is a bipolar aging treatment, which includes the following steps: firstly performing a low-temperature aging treatment at a temperature of 100-150° C. for 1-150 hours; and then performing a high-temperature aging treatment at a temperature of 150-250° C. for 1-100 hours.

10. A heat-resistant cable, characterized in that: It comprises a wire core and an insulating layer covering the wire core, and the material of the wire core is the Al-Cu-RE rare earth aluminum alloy as described in any one of claims 1 to 7.

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