High-performance conductive rare earth aluminum alloy and processing method thereof

Abstract

The invention belongs to the technical field of power cables, and particularly relates to a high-performance conductive rare earth aluminum alloy and a processing method thereof.The high-performance conductive rare earth aluminum alloy is composed of, by mass, 0.8 wt.%-1.2 wt.% of Cu, 0.13 wt.%-0.18 wt.% of Ni, 0.15 wt.%-0.25 wt.% of rare earth elements and the balance Al; wherein the rare earth element is an Er element or a Y element. According to the high-performance conductive rare earth aluminum alloy, the alloy strength is remarkably improved on the premise that high conductivity is kept, and synchronous improvement of the strength and the conductivity is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of power cables, and in particular relates to a high-performance conductive rare earth aluminum alloy and a processing method thereof. Background Art

[0002] There are many types of power cables, among which copper and aluminum are commonly used conductors. Not only are there large differences in the content of the two in the earth's crust (7.45% for aluminum and 0.01% for copper), but there are also significant differences in their electrical conductivity (the conductivity of 99.99% high-purity aluminum is about 65% of the international standard annealed copper IACS). my country is the world's largest producer of aluminum and copper. Due to the scarcity of copper resources and the low quality of its high-end products, it still needs to rely on imports. my country's copper materials have long dominated non-high-end fields such as power cables, forming a "misplaced application" phenomenon of copper resources, resulting in a huge waste of scarce resources. Therefore, it is necessary to replace copper with aluminum, which is more abundant in resources, to achieve "aluminum instead of copper", and use copper in more high-end key development areas to better meet national strategies and sustainable development needs.

[0003] Compared with copper conductors, aluminum conductors not only have relatively low electrical conductivity but also insufficient strength, but they have special advantages in density, manufacturing cost, electromechanical performance, transportation efficiency and conductor laying. Therefore, it is necessary to develop and promote the application of high-performance conductive aluminum alloys and their processing methods. Under the premise of ensuring the high electrical conductivity of aluminum alloys (not less than 59.5% IACS cold processing technology national standard GB / T30552-2014), improving its mechanical properties is the key to the development of aluminum alloy conductor applications. The core issue is how to balance the contradictory relationship between electrical conductivity and strength.

[0004] For this reason, the present invention is specially proposed. Summary of the invention

[0005] The main purpose of the present invention is to provide a high-performance conductive rare earth aluminum alloy and a processing method thereof. The high-performance conductive rare earth aluminum alloy of the present invention significantly improves the alloy strength while maintaining a relatively high conductivity, thereby achieving a simultaneous improvement in strength and conductivity.

[0006] A first aspect of the present invention provides a high-performance conductive rare earth aluminum alloy, which is composed of the following elements in mass percentage: Cu 0.8wt.%~1.2wt.%, Ni 0.13wt.%~0.18wt.%, rare earth elements 0.15wt.%~0.25wt.%, and the balance is Al; wherein the rare earth element is Er element or Y element.

[0007] In some embodiments of the present invention, the high performance conductive rare earth aluminum alloy has a tensile strength >350 MPa, an elongation >23%, and a relative conductivity >62% IACS.

[0008] The second aspect of the present invention provides a processing method for the high-performance conductive rare earth aluminum alloy described in the first aspect, and the processing method of the high-performance conductive rare earth aluminum alloy comprises: preparing an alloy ingot by non-vacuum melting and near-liquidus casting; subjecting the alloy ingot to solid solution treatment to obtain a solid solution alloy with uniform composition; subjecting the solid solution alloy to three alternating rolling and aging processes to obtain the high-performance conductive rare earth aluminum alloy.

[0009] In some embodiments of the present invention, the three-time alternating rolling and aging process includes: performing a first room temperature rolling on the solid solution alloy, and performing a first-level aging treatment on the alloy after the first room temperature rolling; performing a second room temperature rolling on the alloy after the first-level aging treatment, and performing a second-level aging treatment on the alloy after the second room temperature rolling; performing a third room temperature rolling on the alloy after the second-level aging treatment, and performing a third-level aging treatment on the alloy after the third room temperature rolling.

[0010] In some embodiments of the present invention, the deformation of the first room temperature rolling is 75%~85%, the temperature of the first aging treatment is 145℃~160℃, and the time of the first aging treatment is 6 h~8 h; the deformation of the second room temperature rolling is 55%~65%, the temperature of the second aging treatment is 140℃~150℃, and the time of the second aging treatment is 4 h~6 h; the deformation of the third room temperature rolling is 30%~40%, the temperature of the third aging treatment is 130℃~140℃, and the time of the third aging treatment is 2 h~4 h.

[0011] In some embodiments of the present invention, the rolling temperatures of the first room temperature rolling, the second room temperature rolling and the third room temperature rolling are each independently 20°C~26°C; the heating rates of the first aging treatment, the second aging treatment and the third aging treatment are each independently 5°C / min~10°C / min.

[0012] In some embodiments of the present invention, the solution treatment process includes: placing the alloy ingot in a heat treatment furnace, heating the temperature to 390°C~410°C at a heating rate of 5°C / min~10°C / min, keeping the temperature for 55 min~65 min, and then water quenching at a water temperature of 20°C~25°C.

[0013] In some embodiments of the present invention, the non-vacuum melting and near-liquidus casting method includes: preparing pure aluminum ingots, Al-Cu master alloys, Al-Ni master alloys, Al-Er master alloys or Al-Y master alloys according to the required alloy ratio; in an atmospheric environment, using a medium frequency induction melting furnace to heat the pure aluminum ingot to the melting temperature and perform a first heat preservation, and then successively adding Al-Cu master alloys, Al-Ni master alloys, Al-Er master alloys or Al-Y master alloys and performing a second heat preservation to obtain a mixed melt; and casting the mixed melt at a near-liquidus temperature to obtain the alloy ingot.

[0014] In some embodiments of the present invention, in the Al-Cu master alloy, the mass percentage of Cu is 45%~55%; in the Al-Ni master alloy, the mass percentage of Ni is 5%~15%; in the Al-Er master alloy or Al-Y master alloy, the mass percentage of Er or Y is 5%~15%; the purity of the pure aluminum ingot is ≥99.99wt.%.

[0015] In some embodiments of the present invention, the melting temperature is 750°C~760°C, the first insulation time is 5 min~10 min; the heating rate from the furnace heating to the melting temperature is 30°C / min~80°C / min; the temperature of the mixed melt is controlled at 665°C~675°C during casting.

[0016] Compared with the prior art, the present invention achieves the following technical effects: The high-performance conductive rare earth aluminum alloy provided by the present invention significantly improves the alloy strength while maintaining relatively high electrical conductivity, thereby achieving simultaneous improvement in strength and electrical conductivity.

[0017] The present invention not only has the effects of purification, refinement and alloying by adding rare earth elements (Er or Y) to the Al-Cu-Ni alloy, but also regulates the substructure configurations such as nano-scale precipitation phases, stacking faults, dislocations, twins, etc. in the alloy during three alternating processing processes of rolling and aging. Compared with the Al-Cu-Ni alloy without adding rare earth elements, the alloy strength is significantly improved while maintaining a relatively high electrical conductivity.

[0018] The present invention adopts a three-time alternating rolling and aging processing process to prepare the Al-Cu-Ni-RE alloy. The Al-Cu-Ni-RE alloy prepared by the method of the present invention has excellent mechanical properties and electrical properties, solves the contradictory relationship between the mechanical and electrical properties of the existing conductive aluminum alloy, obtains a high-performance conductive rare earth aluminum alloy material with integrated structure and function, and improves the balance point of mechanical-electrical properties.

[0019] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented according to the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only used for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. In the accompanying drawings: Figure 1 A processing flow chart of a high performance conductive rare earth aluminum alloy according to some embodiments of the present invention; Figure 2 The engineering stress-strain curve of the Al-1Cu-0.15Ni-0.2Er alloy prepared in Example 1 of the present invention after primary aging (155°C×8 h); Figure 3 The engineering stress-strain curve of the Al-1Cu-0.15Ni-0.2Er alloy prepared in Example 1 of the present invention after secondary aging (145°C×4 h); Figure 4 The engineering stress-strain curve of the Al-1Cu-0.15Ni-0.2Er alloy prepared in Example 1 of the present invention after three-stage aging (135°C×2 h); Figure 5 The engineering stress-strain curve of the Al-1Cu-0.15Ni-0.2Y alloy prepared in Example 2 of the present invention after primary aging (155°C×8 h); Figure 6 The engineering stress-strain curve of the Al-1Cu-0.15Ni-0.2Y alloy prepared in Example 2 of the present invention after secondary aging (145°C×4 h); Figure 7 The engineering stress-strain curve of the Al-1Cu-0.15Ni-0.2Y alloy prepared in Example 2 of the present invention after three-stage aging (135°C×2 h); Figure 8 The engineering stress-strain curve of the Al-1Cu-0.15Ni alloy prepared in Comparative Example 1 of the present invention after primary aging (155°C×8 h); Fig. 9 The engineering stress-strain curve of the Al-1Cu-0.15Ni alloy prepared in Comparative Example 1 of the present invention after secondary aging (145°C×4 h); Fig.10The engineering stress-strain curve of the Al-1Cu-0.15Ni alloy prepared in Comparative Example 1 of the present invention after three-stage aging (135°C×2 h); Fig.11 The figure shows the variation rules of the relative electrical conductivity of the alloys prepared in the embodiments of the present invention and the comparative examples. DETAILED DESCRIPTION

[0021] The exemplary embodiments of the present invention will be described in more detail below with reference to specific embodiments. It should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present invention and to enable the scope of the present invention to be fully communicated to those skilled in the art.

[0022] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which the present invention belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention; the terms "including" and "having" in the specification and claims of the present invention and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0023] In the description of the embodiments of the present invention, technical terms such as "first" and "second" are only used to distinguish different objects and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features.

[0024] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present invention. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0025] In the description of the embodiments of the present invention, the term "and / or" is only a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B may represent: A exists, A and B exist at the same time, and B exists. In addition, the character " / " in this document generally indicates that the associated objects before and after are in an "or" relationship.

[0026] In the description of the embodiments of the present invention, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0027] China's Inner Mongolia region is rich in rare earth resources. Rare earth elements (RE) have typical metallic properties and are extremely active in chemical properties. They can interact with almost all elements except inert gases and have the ability to absorb a large amount of gas. Due to their unique properties, rare earth elements can produce deoxidation, degassing and impurity removal in aluminum alloys, and can also refine grains, enhance thermal stability, and have good high-temperature and room-temperature plasticity, which can significantly improve the comprehensive performance of the alloy.

[0028] The high-performance conductive rare earth aluminum alloy of the present invention is composed of the following elements in percentage by mass: 0.8wt.%~1.2wt.% copper (Cu), 0.13wt.%~0.18wt.% nickel (Ni), 0.15wt.%~0.25wt.% rare earth element (RE), and the balance is aluminum (Al); wherein the rare earth element is erbium (Er) element or yttrium (Y) element.

[0029] In the embodiments of the present invention, rare earth microalloying is performed on an Al-Cu-Ni alloy system to form a conductive rare earth aluminum alloy Al-Cu-Ni-RE. By adding rare earth elements (Er or Y) to the Al-Cu-Ni alloy, it not only has the effects of purification, refinement and alloying, but also regulates the substructure configurations such as nanoscale precipitation phases, stacking faults, dislocations, and twins in the alloy during the three alternating processes of rolling and aging. Compared with the alloy without adding rare earth elements, the strength of the alloy is significantly improved while maintaining a higher conductivity.

[0030] In the high performance conductive rare earth aluminum alloy provided by the present invention, the mass percentage of the Cu element can be 0.80%, 0.81%, 0.82%, 0.83%, 0.84%, 0.85%, 0.86%, 0.87%, 0.88%, 0.89%, 0.90%, 0.91%, 0.92%, 0.93%, 0.94%, 0.95%, 0.96%, 0.97%, 0.98%, 0.99%, 1%, 1.12%, 1.14%, 1.15%, 1.16%, 1.18%, 1.2% or any value that meets the above range value. The mass percentage of the Ni element can be 0.13%, 0.14%, 0.15%, 0.16%, 0.17%, 0.18% or any value that meets the above range value. The mass percentage of Er element can be one of 0.15%, 0.16%, 0.17%, 0.18%, 0.19%, 0.2%, 0.21%, 0.22%, 0.23%, 0.24%, 0.25%, or any value satisfying the above range. Or the mass percentage of Y element can be one of 0.15%, 0.16%, 0.17%, 0.18%, 0.19%, 0.2%, 0.21%, 0.22%, 0.23%, 0.24%, 0.25%, or any value satisfying the above range.

[0031] In the embodiment of the present invention, the tensile strength of the high-performance conductive rare earth aluminum alloy is greater than 350 MPa, the elongation is greater than 23%, and the relative conductivity is greater than 62% IACS. While maintaining good conductivity, the mechanical properties are significantly improved. (In GB / T30552-2014, the tensile strength of the aluminum alloy conductor for cold-processed cables is ≥185 MPa, the elongation is ≥1%, and the relative conductivity is ≥59.5% IACS).

[0032] The present invention also provides a processing method for the above-mentioned high-performance conductive rare earth aluminum alloy. The key to this processing method is to perform rare earth micro-alloying on the Al-Cu-Ni alloy system, and obtain the high-performance conductive rare earth aluminum alloy Al-Cu-Ni-RE by adopting a self-designed three-time alternating processing process of rolling plastic deformation and aging treatment, thereby promoting the process of "replacing copper with aluminum" in the wire and cable industry.

[0033] See also Figure 1 As shown, the processing method of the high-performance conductive rare earth aluminum alloy in the present invention is specifically carried out according to the following steps.

[0034] 1) Prepare alloy according to target alloy composition.

[0035] In an embodiment of the present invention, an Al-Cu-Ni-RE alloy composition is prepared according to a required alloy ratio, the alloy composition includes Cu element, Ni element, RE element, and the balance is Al element, wherein the RE element is Er element or Y element.

[0036] In an embodiment of the present invention, the Al-Cu-Ni-RE alloy composition has the following mass percentages of elements: 0.8%-1.2% Cu element, 0.13%-0.18% Ni element, 0.15%-0.25% RE element, and the balance is Al element.

[0037] In an embodiment of the present invention, during smelting, the Cu element is added in the form of an Al-Cu master alloy, and the mass percentage of the Cu element is 45% to 55%.

[0038] Exemplarily, in the Al-Cu master alloy, the mass percentage of the Cu element can be one of 45%, 46%, 47%, 48%, 49%, 50%, 51%, 52%, 53%, 54%, 55% or any value satisfying the above range.

[0039] In an embodiment of the present invention, during smelting, the Ni element is added in the form of an Al-Ni master alloy, and the mass percentage of the Ni element is 5% to 15%.

[0040] Exemplarily, in the Al-Ni master alloy, the mass percentage of Ni element can be one of 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15% or any value satisfying the above range.

[0041] In an embodiment of the present invention, during smelting, the rare earth element RE is added in the form of an Al-RE master alloy, such as an Al-Er master alloy or an Al-Y master alloy, and the mass percentage of the Er or Y element is 5% to 15%.

[0042] For example, in the Al-Er master alloy, the mass percentage of the Er element can be one of 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, or any value satisfying the above range. In the Al-Y master alloy, the mass percentage of the Y element can be one of 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, or any value satisfying the above range.

[0043] In an embodiment of the present invention, in the Al-Cu master alloy, the mass percentage of Cu is 50%; in the Al-Ni master alloy, the mass percentage of Ni is 10%; in the Al-Er master alloy or the Al-Y master alloy, the mass percentage of Er or Y is 10%.

[0044] In the embodiment of the present invention, during smelting, the Al element is added in the form of pure aluminum ingots, and the purity thereof is ≥99.99%.

[0045] In the embodiment of the present invention, the alloy composition can be designed and formulated according to the data results of the Al-Cu-Ni alloy cast conductivity and Young's modulus simulated by JmatPro. At the same time, the addition amount of Al-Cu master alloy, Al-Ni master alloy and Al-RE master alloy is controlled to finally obtain the high-performance conductive rare earth aluminum alloy Al-Cu-Ni-RE.

[0046] 2) Preparation of alloy ingots.

[0047] In an embodiment of the present invention, an alloy ingot is prepared by non-vacuum melting and near-liquidus casting. The non-vacuum melting is carried out by a medium-frequency induction melting furnace, using a graphite crucible, and melting in an atmospheric environment. The mixed melt obtained by melting is used to prepare an alloy ingot by near-liquidus casting.

[0048] In an embodiment of the present invention, a pure aluminum ingot is heated to a melting temperature with a furnace and subjected to a first heat preservation to obtain a pure aluminum melt; then, Al-Cu master alloy, Al-Ni master alloy, Al-Er master alloy or Al-Y master alloy is added in sequence and subjected to a second heat preservation to obtain a mixed melt; and the mixed melt is cast at a near liquidus temperature to obtain an alloy ingot.

[0049] In an embodiment of the present invention, the melting temperature is 750°C to 760°C, and the first holding time is 5 min to 10 min. For example, the melting temperature may be 750°C, 760°C, or any value within the above range. The first holding time may be 5 min, 6 min, 7 min, 8 min, 9 min, 10 min, or any value within the above range.

[0050] In an embodiment of the present invention, the heating rate from the furnace heating to the melting temperature is 30°C / min to 80°C / min. For example, the heating rate may be one of 30°C / min, 40°C / min, 50°C / min, 60°C / min, 70°C / min, 80°C / min, or any value satisfying the above range.

[0051] In an embodiment of the present invention, the smelting process includes adding a pure aluminum ingot into a graphite crucible, using a medium frequency induction melting furnace, in an atmospheric environment, heating the temperature to 750°C~760°C at a heating rate of 30°C / min~80°C / min with the furnace and keeping it warm for 5 min~10 min, adding Al-Cu master alloy, Al-Ni master alloy, Al-Er master alloy or Al-Y master alloy in sequence and keeping it warm for 5 min, and then casting the mixed melt when the temperature reaches the near liquidus temperature to obtain an alloy ingot.

[0052] In an embodiment of the present invention, a graphite mold is used in the near-liquidus casting method, and the temperature of the mixed melt during casting is 665° C. to 675° C. For example, the temperature of the mixed melt can be one of 665° C., 670° C., 675° C., or any value satisfying the above range.

[0053] 3) Solution treatment.

[0054] In an embodiment of the present invention, the alloy ingot is subjected to a solid solution treatment to obtain a solid solution alloy with uniform composition.

[0055] In an embodiment of the present invention, the solution treatment process includes placing the alloy ingot in a heat treatment furnace, heating the furnace to 390°C~410°C at a heating rate of 5°C / min~10°C / min, and keeping the temperature for 55 min~65 min, so that the alloy elements are fully dissolved and then quenched in water, and the water temperature is 20°C~25°C.

[0056] Exemplarily, the heating rate during the solution treatment process can be one of 5°C / min, 6°C / min, 7°C / min, 8°C / min, 9°C / min, 10°C / min, or any value satisfying the above range value. The temperature of the solution treatment can be one of 390°C, 400°C, 410°C, or any value satisfying the above range value. The holding time of the solution treatment can be one of 55 min, 56 min, 57 min, 58 min, 59 min, 60 min, 61 min, 62 min, 63 min, 64 min, 65 min, or any value satisfying the above range value. The water temperature of the water quenching can be one of 20°C, 21°C, 22°C, 23°C, 24°C, 25°C, or any value satisfying the above range value.

[0057] 4) Rolling and aging are performed alternately three times.

[0058] In an embodiment of the present invention, the solid solution alloy is subjected to three alternating rolling and aging processes to obtain a high-performance conductive rare earth aluminum alloy Al-Cu-Ni-RE.

[0059] In an embodiment of the present invention, the three-time alternating rolling and aging processing process includes performing a first room temperature rolling on the solid solution alloy, and performing a first-level aging treatment on the alloy after the first room temperature rolling; performing a second room temperature rolling on the alloy after the first-level aging treatment, and performing a second-level aging treatment on the alloy after the second room temperature rolling; performing a third room temperature rolling on the alloy after the second-level aging treatment, and performing a third-level aging treatment on the alloy after the third room temperature rolling.

[0060] In the embodiment of the present invention, the deformation amount of the first room temperature rolling is 75% to 85%, the temperature of the first aging treatment is 145° C. to 160° C., and the time of the first aging treatment is 6 h to 8 h.

[0061] For example, the deformation of the first room temperature rolling can be one of 75%, 76%, 77%, 78%, 79%, 80%, 81%, 82%, 83%, 84%, 85%, or any value satisfying the above range. The temperature of the first aging treatment can be one of 145°C, 150°C, 155°C, 160°C, or any value satisfying the above range. The time of the first aging treatment can be one of 6 h, 7 h, 8 h, or any value satisfying the above range.

[0062] In the embodiment of the present invention, the deformation amount of the second room temperature rolling is 55% to 65%, the temperature of the second aging treatment is 140° C. to 150° C., and the time of the second aging treatment is 4 h to 6 h.

[0063] For example, the deformation of the second room temperature rolling can be one of 55%, 56%, 57%, 58%, 59%, 60%, 61%, 62%, 63%, 64%, 65%, or any value satisfying the above range. The temperature of the second aging treatment can be one of 140°C, 145°C, 150°C, or any value satisfying the above range. The time of the second aging treatment can be one of 4 h, 5 h, 6 h, or any value satisfying the above range.

[0064] In the embodiment of the present invention, the deformation amount of the third room temperature rolling is 30% to 40%, the temperature of the third aging treatment is 130° C. to 140° C., and the time of the third aging treatment is 2 h to 4 h.

[0065] For example, the deformation of the third room temperature rolling can be one of 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, 40%, or any value satisfying the above range. The temperature of the third aging treatment can be one of 130°C, 135°C, 140°C, or any value satisfying the above range. The time of the third aging treatment can be one of 2 h, 3 h, 4 h, or any value satisfying the above range.

[0066] In an embodiment of the present invention, the rolling temperatures of the first room temperature rolling, the second room temperature rolling and the third room temperature rolling are independently 20° C. to 26° C. For example, the rolling temperatures of the first room temperature rolling, the second room temperature rolling and the third room temperature rolling can be independently one of 20° C., 21° C., 22° C., 23° C., 24° C., 25° C., 26° C. or any value satisfying the above range.

[0067] In an embodiment of the present invention, the heating rates of the first aging treatment, the second aging treatment, and the third aging treatment are independently 5°C / min to 10°C / min. Exemplarily, the heating rates of the first aging treatment, the second aging treatment, and the third aging treatment are independently 5°C / min, 6°C / min, 7°C / min, 8°C / min, 9°C / min, 10°C / min, or any value that satisfies the above range.

[0068] In the embodiments of the present invention, rare earth microalloying is performed on the Al-Cu-Ni alloy system, and a high-performance conductive rare earth aluminum alloy Al-Cu-Ni-RE is obtained by adopting a self-designed three-time alternating processing process of rolling deformation and aging treatment, thereby promoting the process of "replacing copper with aluminum" in the wire and cable industry.

[0069] Unless otherwise defined, the technical terms used in the following examples have the same meanings as those generally understood by those skilled in the art to which the present invention belongs. The experimental reagents used in the following examples, unless otherwise specified, are all conventional biochemical reagents; the raw materials, instruments and equipment used in the following examples, etc., can all be purchased on the market or can be obtained by existing methods; the amounts of the experimental reagents, unless otherwise specified, are the amounts of reagents used in conventional experimental operations; the experimental methods, unless otherwise specified, are all conventional methods.

[0070] Example 1 A high-performance conductive rare earth aluminum alloy Al-1Cu-0.15Ni-0.2Er has the following element proportions by mass percentage: 1 wt.% Cu, 0.15 wt.% Ni, 0.2 wt.% Er, and the balance is Al.

[0071] See also Figure 1 As shown, the processing method of the high-performance conductive rare earth aluminum alloy Al-1Cu-0.15Ni-0.2Er comprises the following steps: (1) The alloy is prepared according to the composition requirements of the Al-Cu-Ni-Er alloy, wherein the Al element is added in the form of an aluminum ingot with a purity of 99.99%; the Cu element is added in the form of an Al-Cu master alloy, and the mass percentage of the Cu element is 50%; the Ni element is added in the form of an Al-Ni master alloy, and the mass percentage of the Ni element is 10%; and the Er element is added in the form of an Al-Er master alloy, and the mass percentage of the Er element is 10%.

[0072] (2) The pure aluminum ingot and the master alloy in step (1) are melted, and an Al-Cu-Ni-Er alloy ingot is prepared by a near-liquidus casting method.

[0073] Specifically, a graphite crucible is used in the smelting process, and an aluminum ingot with a purity of 99.99% is added to the graphite crucible. A medium-frequency induction melting furnace is used, and the temperature is rapidly increased with the furnace in an atmospheric environment at a heating rate of 40°C / min, and the temperature is increased to 760°C and kept for 5 minutes until the aluminum is completely melted; then Al-Cu master alloy, Al-Ni master alloy, and Al-Er master alloy are added in sequence, and after they are completely melted, they are kept for 5 minutes to obtain a mixed melt.

[0074] The Al-Cu-Ni-Er alloy ingot was obtained by adopting a near-liquidus casting method and using a graphite mold and casting at a mixed melt temperature of 670°C.

[0075] (3) subjecting the Al-Cu-Ni-Er alloy ingot prepared in step (2) to a solid solution treatment to obtain a solid solution alloy with uniform composition.

[0076] Solution treatment process: The Al-Cu-Ni-Er alloy ingot is loaded into a heat treatment furnace, and the temperature is slowly raised to 410°C with a heating rate of 10°C / min. After keeping warm for 60 min, it is water quenched at a water temperature of 20°C to obtain a solid solution alloy.

[0077] (4) The solid solution alloy obtained in step (3) is subjected to three alternating processes of rolling and aging to obtain a finished Al-Cu-Ni-Er alloy.

[0078] Specifically, the solid solution alloy obtained in step (3) is subjected to the first room temperature rolling, the rolling temperature is 25°C, the deformation is 80%, and the alloy billet after the first room temperature rolling is heated to 155°C with a heating rate of 10°C / min, and the first aging treatment is performed, and the first aging treatment time is 8 h. Among them, the engineering stress-strain curve after the first aging treatment is as follows Figure 2 shown.

[0079] The alloy billet after the first aging treatment was subjected to a second room temperature rolling, with a rolling temperature of 25°C and a deformation of 60%. The alloy billet after the second room temperature rolling was heated to 145°C with a heating rate of 10°C / min, and then subjected to a second aging treatment, with a second aging treatment time of 4 h. The engineering stress-strain curve after the second aging treatment is shown in FIG. Figure 3 shown.

[0080] The alloy billet after the second aging treatment was subjected to the third room temperature rolling, the rolling temperature was 25°C, the deformation was 40%, the alloy billet after the third room temperature rolling was heated to 135°C with the furnace, the heating rate was 10°C / min, and the third aging treatment was carried out. The third aging treatment time was 2 h, and the Al-1Cu-0.15Ni-0.2Er alloy product was obtained. Among them, the engineering stress-strain curve after the third aging treatment is as follows Figure 4 shown.

[0081] The present invention performs performance tests on the Al-1Cu-0.15Ni-0.2Er alloy product prepared in Example 1. The test results are shown in Table 1.

[0082] Example 2 A high-performance conductive rare earth aluminum alloy Al-1Cu-0.15Ni-0.2Y has the following element proportions by mass percentage: 1 wt.% Cu, 0.15 wt.% Ni, 0.2 wt.% Y, and the balance is Al.

[0083] See also Figure 1 As shown, the processing method of the high-performance conductive rare earth aluminum alloy Al-1Cu-0.15Ni-0.2Y comprises the following steps: (1) The alloy was prepared according to the composition requirements of the Al-1Cu-0.15Ni-0.2Y alloy, wherein the Al element was added in the form of an aluminum ingot with a purity of 99.99%; the Cu element was added in the form of an Al-Cu master alloy with a mass fraction of 50%; the Ni element was added in the form of an Al-Ni master alloy with a mass fraction of 10%; and the Y element was added in the form of an Al-Y master alloy with a mass fraction of 10%.

[0084] (2) The pure aluminum ingot and the master alloy in step (1) are melted, and an Al-Cu-Ni-Y alloy ingot is prepared by a near-liquidus casting method.

[0085] Specifically, a graphite crucible is used in the smelting process, and an aluminum ingot with a purity of 99.99% is added to the graphite crucible. A medium-frequency induction melting furnace is used, and the temperature is rapidly increased with the furnace in an atmospheric environment at a heating rate of 40°C / min, and the temperature is increased to 760°C and kept for 5 minutes until the aluminum is completely melted; then Al-Cu master alloy, Al-Ni master alloy, and Al-Y master alloy are added in sequence, and after they are completely melted, they are kept for 5 minutes to obtain a mixed melt.

[0086] The Al-Cu-Ni-Y alloy ingot was obtained by adopting a near-liquidus casting method and using a graphite mold and casting at a mixed melt temperature of 670°C.

[0087] (3) The Al-Cu-Ni-Y alloy ingot prepared in step (2) is subjected to a solid solution treatment to obtain a solid solution alloy with uniform composition.

[0088] Solution treatment process: The Al-Cu-Ni-Y alloy ingot is loaded into a heat treatment furnace, heated to 410°C with the furnace, the heating rate is 10°C / min, and then water quenched after 60 min at a water temperature of 20°C to obtain a solid solution alloy.

[0089] (4) The solid solution alloy obtained in step (3) is subjected to three alternating processes of rolling and aging to obtain an Al-Cu-Ni-Y alloy product.

[0090] Specifically, the solid solution alloy obtained in step (3) is subjected to the first room temperature rolling, the rolling temperature is 25°C, the deformation is 80%, and the alloy billet after the first room temperature rolling is heated to 155°C with a heating rate of 10°C / min, and the first aging treatment is performed. The first aging treatment time is 8 h. The engineering stress-strain curve after the first aging treatment is as follows: Figure 5 shown.

[0091] The alloy billet after the first aging treatment was subjected to a second room temperature rolling, with a rolling temperature of 25°C and a deformation of 60%. The alloy billet after the second room temperature rolling was heated to 145°C with a heating rate of 10°C / min, and then subjected to a second aging treatment, with a second aging treatment time of 4 h. The engineering stress-strain curve after the second aging treatment is shown in FIG. Figure 6 shown.

[0092] The alloy billet after the second stage of aging was subjected to the third room temperature rolling, the rolling temperature was 25°C, the deformation was 40%, the alloy billet after the third room temperature rolling was heated to 135°C with the furnace, the heating rate was 10°C / min, and the third stage of aging treatment was carried out. The third stage of aging treatment time was 2 h, and the Al-1Cu-0.15Ni-0.2Y alloy product was obtained. Among them, the engineering stress-strain curve after the third stage of aging treatment is shown in Figure 7 shown.

[0093] The present invention performs performance tests on the Al-1Cu-0.15Ni-0.2Y alloy product prepared in Example 2. The test results are shown in Table 1.

[0094] Comparative Example 1 A high-performance conductive aluminum alloy Al-1Cu-0.15Ni has the following element ratios by mass percentage: 1wt.%Cu, 0.15wt.%Ni, and the balance is Al.

[0095] The preparation method of the high-performance conductive aluminum alloy Al-1Cu-0.15Ni comprises the following steps: (1) The alloy was prepared according to the composition requirements of the Al-1Cu-0.15Ni alloy, wherein the Al element was added in the form of an aluminum ingot with a purity of 99.99%; the Cu element was added in the form of an Al-Cu master alloy, and the mass percentage of the Cu element was 50%; and the Ni element was added in the form of an Al-Ni master alloy, and the mass percentage of the Ni element was 10%.

[0096] (2) The pure aluminum ingot and the master alloy in step (1) are melted, and an Al-Cu-Ni alloy ingot is prepared by a near-liquidus casting method.

[0097] Specifically, a graphite crucible is used in the smelting process, and an aluminum ingot with a purity of 99.99% is added to the graphite crucible. A medium-frequency induction melting furnace is used, and the temperature is rapidly increased with the furnace in an atmospheric environment at a heating rate of 40°C / min. After the temperature is increased to 760°C, it is kept warm for 5 minutes until the aluminum is completely melted; then Al-Cu master alloy and Al-Ni master alloy are added in sequence, and after they are completely melted, they are kept warm for 5 minutes to obtain a mixed melt.

[0098] The Al-Cu-Ni alloy ingot was prepared by adopting a near-liquidus casting method and using a graphite mold and casting at a mixed melt temperature of 670°C.

[0099] (3) subjecting the Al-Cu-Ni alloy ingot obtained in step (2) to a solid solution treatment to obtain a solid solution alloy with uniform composition.

[0100] Solution treatment process: The Al-Cu-Ni alloy ingot is loaded into a heat treatment furnace, and the temperature is slowly raised to 410°C with a heating rate of 10°C / min. After keeping warm for 60 min, it is water quenched at a water temperature of 20°C to obtain a solid solution alloy.

[0101] (4) The solid solution alloy obtained in step (3) is subjected to three alternating processes of rolling and aging to obtain an Al-Cu-Ni alloy product.

[0102] Specifically, the solid solution alloy prepared in step (3) is subjected to the first room temperature rolling, the rolling temperature is 25°C, the deformation is 80%, and the alloy billet after the first room temperature rolling is heated to 155°C with a heating rate of 10°C / min, and the first aging treatment is performed, and the first aging treatment time is 8 h. Among them, the engineering stress-strain curve after the first aging treatment is as follows Figure 8 shown.

[0103] The alloy billet after the first aging treatment was subjected to a second room temperature rolling, with a rolling temperature of 25°C and a deformation of 60%. The alloy billet after the second room temperature rolling was heated to 145°C with a heating rate of 10°C / min, and then subjected to a second aging treatment, with a second aging treatment time of 4 h. The engineering stress-strain curve after the second aging treatment is shown in FIG. Fig. 9 shown.

[0104] The alloy billet after the second aging treatment was subjected to the third room temperature rolling, the rolling temperature was 25°C, the deformation was 40%, and the alloy billet after the third room temperature rolling was heated to 135°C with the furnace, the heating rate was 10°C / min, and the third aging treatment was carried out, and the third aging treatment time was 2 h), and the Al-1Cu-0.15Ni alloy product was obtained. Among them, the engineering stress-strain curve after the third aging treatment is as follows Fig.10 shown.

[0105] The present invention performs a performance test on the Al-1Cu-0.15Ni alloy product prepared in Comparative Example 1. The test results are shown in Table 1.

[0106] Performance Testing The finished alloy products obtained in Examples 1-2 and Comparative Example 1 were subjected to a tensile strength test, and the samples were cut into I-shaped flat plate samples using an electric spark wire cutting machine, with the following dimensions: the gauge section length is 25 mm, the thickness is the original thickness of the sample, the width is 4 mm, the clamping section width is 10 mm, the length is 12 mm, and the total length of the sample is 55 mm. After the sample is made, the tensile sample is ground to a smooth surface to remove macroscopic defects such as burrs. Using a universal tensile testing machine, the clamping sections at both ends of the sample are clamped with a universal testing machine fixture and the measurement is started. The strain rate during the tensile test is 1 mm / s, and 3 tensile test samples are selected for testing in each state, and the average value is taken as the final tensile strength and elongation value of the sample.

[0107] The finished alloy products obtained in Examples 1-2 and Comparative Example 1 were subjected to relative conductivity tests. The samples were cut into long flat specimens using an electric spark wire cutting machine. The size was: 2 mm × 40 mm, and the thickness was the original thickness of the specimen. The specimens were polished to be smooth, without oxide scale and macroscopic defects. Using a FM100GH four-probe resistivity tester, the resistance data of the samples were tested and recorded. Three samples were selected for each state and the average value was calculated as the resistance value of the sample. Finally, the international annealed copper standard conductivity percentage (%IACS) was converted into relative conductivity using formula (1-1) in GB / T 351-2019 Metal Material Resistivity Measurement Method.

[0108] %IACS=0.017241 / ρ×100 (1-1) Where, ρ is the volume resistivity of the sample at 20°C, in Ω∙m.

[0109] Table 1 Summary of properties of high performance conductive rare earth aluminum alloys prepared in Examples and Comparative Examples

[0110] Combining Table 1 and Fig.11 It can be seen that the performance of the Al-1Cu-0.15Ni alloy prepared in Comparative Example 1 is significantly lower than that of the Al-Cu-Ni-RE alloy to which trace Er and Y elements are added in Example 1 and Example 2, which indicates that after rare earth microalloying of the Al-Cu-Ni alloy, two performance indicators with contradictory relations can be improved simultaneously and to a large extent: tensile strength and relative conductivity. The tensile strength of the Al-Cu-Ni-RE alloy prepared by the present invention is >350 MPa, the elongation after fracture is >23%, and the relative conductivity is >62%IACS.

[0111] Under normal conditions, the present invention improves the electrical conductivity of the alloy while significantly improving its tensile strength, thereby achieving a simultaneous improvement in strength and electrical conductivity and solving the engineering problem of insufficient strength of existing aluminum alloy conductors.

[0112] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A high-performance conductive rare earth aluminum alloy, characterized in that: The high-performance conductive rare earth aluminum alloy is composed of the following elements in percentage by mass: Cu 0.8wt.%~1.2wt.%, Ni 0.13wt.%~0.18wt.%, rare earth element 0.15wt.%~0.25wt.%, balance is Al; wherein the rare earth element is Er element or Y element.

2. The high performance conductive rare earth aluminum alloy according to claim 1, characterized in that: The high-performance conductive rare earth aluminum alloy has a tensile strength of >350 MPa, an elongation of >23%, and a relative conductivity of >62% IACS.

3. A method for processing a high-performance conductive rare earth aluminum alloy according to claim 1 or 2, characterized in that: The processing method of the high-performance conductive rare earth aluminum alloy comprises: The alloy ingot is prepared by non-vacuum melting and near-liquidus casting method; The alloy ingot is subjected to a solid solution treatment to obtain a solid solution alloy with uniform composition; The solid solution alloy is subjected to rolling and aging processes three times in an alternating manner to obtain the high-performance conductive rare earth aluminum alloy.

4. The processing method of high performance conductive rare earth aluminum alloy according to claim 3, characterized in that: The three-time alternating rolling and aging process includes: The solid solution alloy is subjected to a first room temperature rolling, and the alloy after the first room temperature rolling is subjected to a first level aging treatment; Performing a second room temperature rolling on the alloy after the first aging treatment, and performing a second aging treatment on the alloy after the second room temperature rolling; The alloy after the second-stage aging treatment is subjected to a third room temperature rolling, and the alloy after the third room temperature rolling is subjected to a third aging treatment.

5. The processing method of high performance conductive rare earth aluminum alloy according to claim 4, characterized in that: The deformation amount of the first room temperature rolling is 75% to 85%, the temperature of the first aging treatment is 145° C. to 160° C., and the time of the first aging treatment is 6 h to 8 h; The deformation amount of the second room temperature rolling is 55% to 65%, the temperature of the second aging treatment is 140° C. to 150° C., and the time of the second aging treatment is 4 h to 6 h; The deformation amount of the third room temperature rolling is 30% to 40%, the temperature of the third aging treatment is 130° C. to 140° C., and the time of the third aging treatment is 2 h to 4 h.

6. The method for processing a high performance conductive rare earth aluminum alloy according to claim 4, characterized in that: The rolling temperatures of the first room temperature rolling, the second room temperature rolling and the third room temperature rolling are independently 20° C. to 26° C.; The heating rates of the first aging treatment, the second aging treatment and the third aging treatment are independently 5°C / min to 10°C / min.

7. The processing method of high performance conductive rare earth aluminum alloy according to claim 3, characterized in that: The solution treatment process includes: placing the alloy ingot in a heat treatment furnace, heating it to 390°C~410°C at a heating rate of 5°C / min~10°C / min, keeping it at a temperature for 55 min~65 min, and then quenching it in water at a water temperature of 20°C~25°C.

8. The method for processing a high performance conductive rare earth aluminum alloy according to claim 3, characterized in that: The non-vacuum melting and near-liquidus casting method comprises: Prepare pure aluminum ingots, Al-Cu master alloys, Al-Ni master alloys, Al-Er master alloys or Al-Y master alloys according to the required alloy ratio; In an atmospheric environment, a medium frequency induction melting furnace is used to heat a pure aluminum ingot to a melting temperature and perform a first heat preservation, and then Al-Cu master alloy, Al-Ni master alloy, Al-Er master alloy or Al-Y master alloy are sequentially added and a second heat preservation is performed to obtain a mixed melt; and The mixed melt is cast at a near liquidus temperature to obtain the alloy ingot.

9. The method for processing a high performance conductive rare earth aluminum alloy according to claim 8, characterized in that: In the Al-Cu master alloy, the mass percentage of Cu is 45% to 55%; In the Al-Ni master alloy, the mass percentage of Ni is 5% to 15%; In the Al-Er master alloy or Al-Y master alloy, the mass percentage of Er or Y is 5% to 15%; The purity of the pure aluminum ingot is ≥99.99wt.%.

10. The method for processing a high performance conductive rare earth aluminum alloy according to claim 8, characterized in that: The smelting temperature is 750°C to 760°C, and the first holding time is 5 min to 10 min; The heating rate of the furnace to the melting temperature is 30°C / min~80°C / min; During the casting, the temperature of the mixed melt is controlled to be 665° C.-675° C.

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