Aluminum alloy wire

Abstract

To improve properties of an aluminum alloy wire.SOLUTION: An aluminum alloy wire contains aluminum, nickel, zirconium, and titanium, wherein the aluminum alloy wire contains an aluminum-titanium-zirconium compound.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to an aluminum alloy wire. [Background technology]

[0002] Japanese Patent No. 6683281 (Patent Document 1) describes a technology relating to an aluminum alloy wire that has a high level of strength, elongation, electrical conductivity, and heat resistance in a well-balanced manner. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6683281 Summary of the Invention [Problem to be solved by the invention]

[0004] Railway vehicles, automobiles, and other electrical equipment use electric wires and cables that use copper or copper alloys as conductors. In recent years, there has been a demand for lighter electric wires and cables. For this reason, the use of aluminum alloy wires, which use aluminum, which has a smaller specific gravity than copper, as the wiring material, has been considered.

[0005] However, since the conductivity of aluminum is lower than that of copper, in order to obtain electrical properties similar to those of a copper wire, the cross-sectional area of ​​an aluminum alloy wire must be larger than that of a copper wire. This means that the size of the aluminum alloy wire becomes larger. Furthermore, if the size of the aluminum alloy wire becomes larger, it becomes impossible to arrange the aluminum alloy wire in a designated arrangement space. That is, to suppress the increase in size, an aluminum alloy wire with high conductivity is desired. [Means for solving the problem]

[0006] In one embodiment, the aluminum alloy wire contains aluminum, nickel, zirconium, and titanium, where the aluminum alloy wire includes an aluminum-titanium-zirconium compound. [Effects of the Invention]

[0007] According to one embodiment, an aluminum alloy wire having high electrical conductivity can be provided. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a flowchart showing a manufacturing process of an aluminum alloy wire. [Figure 2] 1 is a graph showing the relationship between titanium concentration and tensile strength. [Figure 3] 1 is a graph showing the relationship between titanium concentration and electrical conductivity. [Figure 4] 1 is a graph showing the relationship between titanium concentration and elongation characteristics. [Figure 5] This is an observation result showing crystallized matter consisting of an "Al-Ni-Zr" compound. [Figure 6] This is an observation result showing precipitates consisting of "Al-Ti-Zr" compounds. DETAILED DESCRIPTION OF THE INVENTION

[0009] <Consideration of improvements> In aluminum alloy wires, zirconium (Zr) is added to aluminum (Al) to improve tensile strength and electrical conductivity. Specifically, the concentration of added zirconium is increased and a zirconium compound is precipitated by aging heat treatment. Meanwhile, aluminum base metal contains iron (Fe) as an inevitable impurity, and aluminum and iron form a compound (FeAl3). This compound crystallizes at grain boundaries and reduces the elongation properties of the aluminum alloy wire. For this reason, it is difficult to improve the elongation properties of aluminum alloy wires to which zirconium is added. In other words, there is room for improvement in aluminum alloy wires to which zirconium is added in terms of improving tensile strength, elongation properties, and electrical conductivity in a balanced manner.

[0010] In response to this issue, the addition of cobalt (Co) to aluminum in addition to zirconium has been considered. This is because cobalt forms a compound with iron, an inevitable impurity, which suppresses the formation of FeAl3, a compound of iron and aluminum, thereby suppressing the deterioration of elongation caused by FeAl3. Therefore, aluminum alloy wires to which zirconium and cobalt are added are excellent in that they can improve tensile strength, elongation, and electrical conductivity in a well-balanced manner.

[0011] However, because cobalt is an expensive element, aluminum alloy wires made by adding zirconium and cobalt to aluminum are expensive to manufacture. For this reason, the use of elements that can reduce manufacturing costs while improving tensile strength, elongation, and electrical conductivity in a balanced manner is being considered in place of cobalt. Specifically, the use of nickel (Ni) in place of cobalt is being considered. This is because nickel also forms a compound with iron, an unavoidable impurity, which suppresses the formation of "FeAl3," a compound of iron and aluminum, thereby preventing a decrease in elongation.

[0012] However, the present inventors have newly discovered that aluminum alloy wires containing zirconium and nickel added to aluminum tend to have lower tensile strength than aluminum alloy wires containing zirconium and cobalt added to aluminum. That is, there is room for improvement in terms of improving the tensile strength of aluminum alloy wires containing zirconium and nickel added to aluminum. Therefore, there is a need for a method for improving the tensile strength of aluminum alloy wires containing zirconium and nickel added to aluminum. In particular, if the tensile strength of aluminum alloy wires containing zirconium and nickel added to aluminum can be improved, it is believed that it will be possible to reduce manufacturing costs while improving the tensile strength, elongation characteristics, and electrical conductivity in a balanced manner.

[0013] Therefore, in this embodiment, an improvement is made to improve the tensile strength of an aluminum alloy wire in which zirconium and nickel are added to aluminum. The technical idea of ​​this improvement will be described below.

[0014] <Basic Concept of the Embodiment> The basic idea of ​​the present embodiment is to increase the amount of precipitates made of fine zirconium compounds in an aluminum alloy wire made by adding zirconium and nickel to aluminum, thereby improving the tensile strength, elongation characteristics, and electrical conductivity of the aluminum alloy wire in a well-balanced manner.

[0015] What is important here is to increase the number of fine precipitates, which allows precipitation strengthening to be fully exerted, resulting in improved tensile strength and elongation characteristics.

[0016] Furthermore, an increase in the amount of precipitates made of zirconium compounds means a decrease in the amount of zirconium dissolved in aluminum. Considering that a decrease in the amount of zirconium dissolved in aluminum improves the electrical conductivity of the aluminum alloy wire, the basic concept of this embodiment also makes it possible to improve electrical conductivity.

[0017] Therefore, according to the basic concept, in an aluminum alloy wire in which zirconium and nickel are added to aluminum, the tensile strength, elongation characteristics, and electrical conductivity can be improved in a well-balanced manner.

[0018] Specifically, in order to realize the basic idea of ​​increasing the amount of precipitates made of fine zirconium compounds, in this embodiment, titanium (Ti) is further added to an aluminum alloy wire in which zirconium and nickel are added to aluminum. This is based on the findings of the inventors' studies that titanium has the function of making it easier for zirconium dissolved in aluminum to precipitate as a zirconium compound. That is, the inventors confirmed that adding titanium causes precipitation not only as an "Al-Zr compound" but also as an "Al-Ti-Zr compound," and therefore recognized that adding titanium is effective from the viewpoint of increasing the amount of precipitated zirconium compounds.

[0019] Furthermore, in order to increase the number of fine precipitates, in this embodiment, further improvements are made to the manufacturing method from the viewpoint of increasing the amount of precipitates made of zirconium compounds, and improvements are also made to the manufacturing method for obtaining fine zirconium compounds.

[0020] In the following, first, a method for manufacturing an aluminum alloy wire according to the present embodiment will be described, and then, the ingenuity in the manufacturing method will be described.

[0021] <Method of manufacturing aluminum alloy wire> FIG. 1 is a flowchart showing the manufacturing process of an aluminum alloy wire.

[0022] First, a molten metal for producing an aluminum alloy wire is prepared (S101). The molten metal is obtained, for example, by melting an aluminum raw material, then adding an aluminum-nickel master alloy, an aluminum-zirconium master alloy, and an aluminum-titanium master alloy, and then stirring the mixture. The method for mixing and melting the raw materials is not particularly limited. The obtained molten metal is transferred to and stored in a storage tank. The storage tank is equipped with a pouring nozzle so that the molten metal can flow out of the storage tank.

[0023] Next, casting is performed by flowing the molten metal from the storage tank through a pouring nozzle and pouring it into a mold (S102). For example, a continuous casting machine capable of belt-wheel type continuous casting can be used as the mold. The continuous casting machine is configured, for example, to include a cylindrical wheel with a groove on its outer circumferential surface and a belt, with the belt looped around a portion of the outer circumferential surface of the wheel. With a continuous casting machine configured in this manner, molten metal is poured into the space (groove) formed between the wheel and the belt, and then cooled and solidified, thereby continuously producing cast material.

[0024] Next, if necessary, the cast material is formed into a wire rod (roughly drawn wire) having a diameter of, for example, 9.5 mm so as to facilitate wire drawing (S103). Here, for example, the cast material is subjected to plastic working. Examples of plastic working include rolling, swaging, and drawing.

[0025] The obtained wire rod is then subjected to cold drawing to be processed into a drawn wire material having a final wire diameter of φ=0.45 mm, which is the diameter of the cable wire (S104). For example, the wire rod is repeatedly drawn through a die while being transported by rollers, and is finally drawn into a drawn wire material.

[0026] Next, the drawn wire material is subjected to aging heat treatment (S105). This allows an aluminum alloy wire to be produced (S106). Here, "aging heat treatment" refers to heat treatment that causes age hardening (precipitation hardening). Age hardening is a phenomenon in which, for example, additive elements contained in aluminum precipitate as precipitates, and these precipitates become obstacles to the transformation deformation of aluminum atoms, making the aluminum alloy wire less susceptible to plastic deformation. In this way, the aluminum alloy wire obtained by performing aging heat treatment can have improved tensile strength and elongation characteristics.

[0027] <Features of the embodiment> Next, the features of this embodiment will be described.

[0028] The basic idea of ​​the present embodiment is to improve the tensile strength, elongation characteristics, and electrical conductivity of an aluminum alloy wire in a well-balanced manner by increasing the amount of precipitates made of fine zirconium compounds in an aluminum alloy wire obtained by adding zirconium and nickel to aluminum. To realize this basic idea, the present embodiment is devised to increase the amount of precipitates made of fine zirconium compounds.

[0029] First, a first characteristic of this embodiment is that "high-temperature rapid cooling casting" is performed in the casting process of forming a cast material by casting a molten metal containing aluminum, nickel, zirconium, and titanium. The main purpose of this "high-temperature rapid cooling casting" is to increase the amount of zirconium dissolved in aluminum. This is based on the consideration that if the amount of zirconium dissolved in aluminum can be increased, the amount of zirconium compounds precipitated in the subsequent aging heat treatment process can be increased. In other words, "high-temperature rapid cooling casting" is performed to increase the amount of zirconium dissolved in aluminum in advance, from the perspective of increasing the amount of zirconium compounds precipitated.

[0030] In particular, the technical significance of "high temperature" in "high-temperature quench casting" is that, at a high temperature, the amount of zirconium dissolved in aluminum can be increased, as can be seen from the aluminum / zirconium phase diagram. The high temperature referred to here is assumed to be a temperature of about "850°C," which is higher than 800°C. For example, the temperature of a typical molten metal is about 800°C, but in this embodiment, the temperature of the molten metal is set to a high temperature of "850°C" in order to increase the amount of zirconium dissolved in aluminum.

[0031] In "high-temperature quench casting," the material is quenched from a state in which the amount of zirconium dissolved in aluminum has been increased by heating to a high temperature. The technical significance of this "quenching" is that by quenching from a high temperature, the zirconium dissolved in aluminum is maintained in a state of solid solution (forced solid solution state) without crystallizing zirconium compounds, thereby increasing the amount of zirconium dissolved in aluminum. In other words, since the crystallization rate of zirconium compounds is slow, the technical significance of "quenching" is to suppress the crystallization of zirconium by "quenching" and maintain the forced solid solution state of zirconium. Thus, to realize the basic concept of this embodiment, it is important to increase the amount of zirconium dissolved in aluminum. According to "high-temperature quench casting," the synergistic effect of the increase in the amount of zirconium dissolved in aluminum due to the "high temperature" and the suppression of crystallization of zirconium compounds due to "quenching" makes it possible to maintain the increased amount of zirconium dissolved in aluminum (forced solid solution state) after the casting process.

[0032] Here, "crystallization" refers to the phenomenon in which a solid appears from a liquid, while "precipitation" refers to the phenomenon in which a solid appears from a solid, and in this specification, "crystallization" and "precipitation" are distinguished.

[0033] As described above, a first feature of the first embodiment is that the casting process for forming a cast material by casting a molten metal containing aluminum, nickel, zirconium, and titanium is a "high-temperature quench casting" process. This "high-temperature quench casting" process is a process for cooling the molten metal from a state in which the temperature of the molten metal is 850°C or higher at a cooling rate that suppresses the crystallization of zirconium compounds. For example, the cooling rate that suppresses the crystallization of zirconium compounds is desirably 20°C / s or higher. "High-temperature quench casting" can be achieved, for example, by using a Properti continuous casting machine or a twin-roll casting machine.

[0034] In this embodiment, the molten metal contains nickel. The technical significance of including nickel will be explained below. For example, suppose the molten metal contains aluminum but does not contain nickel. In this case, considering that the molten metal contains iron as an inevitable impurity, aluminum-iron ("Al-Fe") crystallizes in the casting process. These Al-Fe crystallized products exist in the form of large plates, which can easily cause wire breakage.

[0035] On the other hand, if nickel is contained in the molten metal, the nickel acts as a getter for the inevitable impurity iron, resulting in the crystallization of aluminum-nickel-iron ("Al-Ni-Fe"). Here, the crystallization rate of nickel is faster than that of zirconium, and "Al-Ni-Fe" crystallizes not only in general casting processes but also in the "high-temperature quench casting" process described above. In this regard, "Al-Ni-Fe" crystallized matter, unlike "Al-Fe" crystallized matter, exists in fine (thread-like) form, which has the advantage of being less likely to cause wire breakage.

[0036] However, in a general casting process, the "Al-Ni-Fe" crystals tend to be concentrated, but in the "high-temperature quench casting" process, the "Al-Ni-Fe" crystals are dispersed. In this respect, the present inventors have newly discovered that "high-temperature quench casting" is useful for improving the tensile strength and elongation characteristics of an aluminum alloy wire. That is, the present inventors have found that the more finely dispersed the "Al-Ni-Fe" crystals are, the more desirable it is from the viewpoint of improving the tensile strength and elongation characteristics of an aluminum alloy wire, and have implemented the following innovations based on this finding. This innovation is the second characteristic of the present embodiment.

[0037] A second feature of this embodiment is that an aging heat treatment is performed after the wiredrawing process. The "Al-Ni-Fe" crystallized particles dispersed and crystallized by the above-mentioned "high-temperature quench casting" are further finely dispersed through the wiredrawing process, and are present dispersedly in the aluminum alloy that has been transformed into a processed structure through the wiredrawing process. For example, by drawing a wire rod with a diameter of 9.5 mm into a drawn wire with a diameter of 0.45 mm, the "Al-Ni-Fe" crystallized particles are refined to a minimum of approximately 20 nm.

[0038] Then, after the wiredrawing process, an aging heat treatment is performed. During this process, the processed structure undergoes the following stages: "recovery," "recrystallization," and "grain growth," resulting in coarsening. However, in this embodiment, since the wiredrawing process is performed before the aging heat treatment, the aging heat treatment is performed in a state in which the "Al-Ni-Fe" crystals are finely dispersed. As a result, the pinning effect of the finely dispersed "Al-Ni-Fe" crystals suppresses "grain growth" of the aluminum alloy, so the crystals generated by recrystallization become small and the number of crystals increases. Therefore, the aging heat treatment can increase the number of precipitation sites where the "Al-Zr" compound precipitates. In other words, the second characteristic of performing the aging heat treatment after the wiredrawing process has the technical significance of increasing the number of precipitation sites for the "Al-Zr" precipitates by increasing the refinement and dispersion of the "Al-Ni-Fe" crystals.

[0039] Then, by the aging heat treatment, zirconium dissolved in aluminum precipitates as "Al-Zr" compounds, resulting in precipitation strengthening. However, as the aging heat treatment progresses, further precipitation of zirconium in the "Al-Zr" compounds causes coarsening of the "Al-Zr" compounds, which may result in the loss of the precipitation strengthening mechanism. In this regard, in the present embodiment, the crystals of the aluminum alloy can be made small, and the small crystals can suppress the coarsening of the "Al-Zr" compounds, thereby maintaining the precipitation strengthening mechanism. Therefore, the second characteristic feature of the present embodiment allows a large number of fine "Al-Zr" compounds to be precipitated, thereby improving the tensile strength and elongation characteristics of the aluminum alloy wire.

[0040] Next, a third feature of the present embodiment is that an aluminum alloy wire containing aluminum, nickel, zirconium, and titanium contains an aluminum-titanium-zirconium compound ("Al-Ti-Zr" compound). That is, the third feature is that titanium is further added to an aluminum alloy wire in which zirconium and nickel are added to aluminum. As a result, when aging heat treatment is performed, not only the "Al-Zr" compound but also the "Al-Ti-Zr" compound precipitates, and the amount of precipitated zirconium can be increased. In other words, it can be said that titanium has the function of enhancing the effect of precipitating zirconium that is solid-solved in aluminum.

[0041] Therefore, according to the third feature, the addition of titanium can increase the amount of precipitated fine zirconium compounds, thereby improving the tensile strength and elongation characteristics of the aluminum alloy wire. In other words, an increase in the amount of precipitated fine zirconium compounds means a decrease in the amount of zirconium dissolved in aluminum, thereby improving the electrical conductivity of the aluminum alloy wire.

[0042] From the above, the characteristics of the aluminum alloy wire can be improved by each of the first, second, and third characteristic points. In particular, by combining the first, second, and third characteristic points, a synergistic effect of the increase in the amount of solid solution of zirconium by the first characteristic point, the increase in fine zirconium precipitates by the second characteristic point, and the precipitation of the "Al-Ti-Zr" compound by the third characteristic point can be achieved, resulting in a well-balanced improvement in the tensile strength, elongation, and electrical conductivity of the aluminum alloy.

[0043] <Specific conditions for aging heat treatment> As described above, the precipitation of fine zirconium compounds is carried out by aging heat treatment. Therefore, it is considered that the improvement in the properties of the aluminum alloy wire (the "high-temperature quench casting" process is carried out at a casting temperature of 850°C and a quenching rate of 25°C / s) brought about by the precipitation of fine zirconium compounds depends on the specific conditions of the aging heat treatment. That is, from the viewpoint of improving the properties of the aluminum alloy wire, the specific conditions of the aging heat treatment are important. Therefore, in the following, the specific conditions of the aging heat treatment will be examined from the viewpoint of improving the properties of the aluminum alloy wire. In particular, the time of the aging heat treatment will be examined.

[0044] The temperature of the aging heat treatment is 350° C., and the atmosphere of the aging heat treatment is air at 1 atmosphere.

[0045] [Table 1]

[0046] Table 1 shows the results of measuring the tensile strength of an aluminum alloy wire (Al-0.4 mass% Ni-0.4 mass% Zr-Ti alloy wire) using the duration of aging heat treatment, titanium concentration, and "Ti / Zr ratio" as parameters. Table 1 shows that the tensile strength is greater when the aging heat treatment is not performed, regardless of whether the titanium concentration is varied from 0 mass% to 0.15 mass%. Furthermore, when the aging heat treatment is performed, by marking the combinations of the aging heat treatment time, titanium concentration, and "Ti / Zr ratio" that result in a tensile strength of 175 MPa or more, it can be seen that the tensile strength tends to be maintained as the aging heat treatment time is longer.

[0047] The tensile strength was measured in accordance with JIS Z 2241 (Method of tensile testing of metallic materials, 1998).

[0048] [Table 2]

[0049] Table 2 shows the results of measuring the electrical conductivity of an aluminum alloy wire (Al-0.4 mass%Ni-0.4 mass%Zr-Ti alloy wire) using the duration of aging heat treatment, titanium concentration, and "Ti / Zr ratio" as parameters. In Table 2, when dots are placed on the combinations of aging heat treatment time, titanium concentration, and "Ti / Zr ratio" that result in an electrical conductivity of 55 (%IACS) or more, it can be seen that the longer the aging heat treatment time, the better the electrical conductivity tends to be maintained.

[0050] Here, "%IACS" refers to the International Standard Annealed Copper (resistivity: 1.7241 x 10 -8 The conductivity is expressed as an index with a conductivity of 100%.

[0051] [Table 3]

[0052] Table 3 shows the results of measuring the elongation properties of aluminum alloy wires (Al-0.4 mass%Ni-0.4 mass%Zr-Ti alloy wires) using the duration of aging heat treatment, titanium concentration, and "Ti / Zr ratio" as parameters. In Table 3, when dots are placed on the combinations of aging heat treatment time, titanium concentration, and "Ti / Zr ratio" that result in elongation properties of 10% or more, it can be seen that the longer the aging heat treatment time, the more the electrical conductivity tends to be secured.

[0053] From the viewpoint of achieving a well-balanced improvement in tensile strength, electrical conductivity, and elongation characteristics, a longer aging heat treatment time tends to be more desirable. In view of this, in this embodiment, the aging heat treatment is performed at 350°C for 96 hours.

[0054] The elongation was measured in accordance with JIS Z 2241 (Method of tensile testing of metallic materials, 1998).

[0055] <Quantitative considerations regarding titanium concentration> Next, a quantitative consideration of titanium concentration will be explained. Specifically, the range of titanium concentration that can improve tensile strength, electrical conductivity, and elongation characteristics in a well-balanced manner will be examined.

[0056] In the following study, the aging heat treatment conditions are set to 350°C for 96 hours.

[0057] FIG. 2 is a graph showing the relationship between titanium concentration and tensile strength.

[0058] As shown in Figure 2, the addition of titanium improves the tensile strength. This is thought to be due to the increased precipitation of fine zirconium compounds (Al-Zr compounds and Al-Ti-Zr compounds) by adding titanium, resulting in improved tensile strength. In particular, when the Ti / Zr ratio is in the range of 0.1875 to 0.375, the tensile strength can be increased to 175 MPa or more. For example, when the titanium concentration is in the range of 0.075 to 0.15 mass%, the tensile strength can be increased to 175 MPa or more. The Ti / Zr ratio refers to the ratio of the titanium concentration to the zirconium concentration.

[0059] FIG. 3 is a graph showing the relationship between titanium concentration and electrical conductivity.

[0060] As shown in Figure 3, adding titanium improves electrical conductivity when the titanium concentration is low, but decreases as the titanium concentration increases. This is thought to be because when the titanium concentration is low, most of the titanium dissolved in aluminum precipitates as an "Al-Ti-Zr" compound, improving electrical conductivity, but as the titanium concentration increases, the amount of titanium dissolved in aluminum increases without precipitating as an "Al-Ti-Zr" compound, resulting in a decrease in electrical conductivity.

[0061] 3, it can be seen that when the "Ti / Zr ratio" is in the range of 0.125 to 0.3125, the electrical conductivity can be made 55 (%IACS) or more. For example, when the titanium concentration is in the range of 0.05 mass% to 0.125 mass%, the electrical conductivity can be made 55 (%IACS) or more.

[0062] FIG. 4 is a graph showing the relationship between titanium concentration and elongation characteristics.

[0063] As shown in Figure 4, when the "Ti / Zr ratio" is in the range of 0.125 to 0.375, the elongation can be made 10% or more. For example, when the titanium concentration is in the range of 0.05% by mass to 0.15% by mass, the elongation can be made 10% or more.

[0064] From the above, referring to FIGS. 2 to 4, it can be seen that when the "Ti / Zr ratio" is in the range of 0.1875 to 0.3125, the tensile strength, elongation, and electrical conductivity can be improved in a balanced manner. For example, when the titanium concentration is 0.075% by mass to 0.125% by mass, the tensile strength, elongation, and electrical conductivity can be improved in a balanced manner. Specifically, when the "Ti / Zr ratio" is 0.1875 to 0.3125, an aluminum alloy wire (Al-Ni-Zr-Ti alloy wire) having a tensile strength of 175 MPa or more, an electrical conductivity of 55% IACS or more, and an elongation of 10% or more can be realized. For example, when the titanium concentration is 0.075% by mass to 0.125% by mass, an aluminum alloy wire having a tensile strength of 175 MPa or more, an electrical conductivity of 55% IACS or more, and an elongation of 10% or more can be realized.

[0065] Furthermore, when the "Ti / Zr ratio" is more than 0.25 and not more than 0.3125, an aluminum alloy wire (Al-Ni-Zr-Ti alloy wire) having a tensile strength of 185 MPa or more, an electrical conductivity of 55% IACS or more, and an elongation property of 10% or more can be realized. For example, when the titanium concentration is more than 0.1 mass% and not more than 0.125 mass%, an aluminum alloy wire (Al-Ni-Zr-Ti alloy wire) having a tensile strength of 185 MPa or more, an electrical conductivity of 55% IACS or more, and an elongation property of 10% or more can be realized.

[0066] <Cross-sectional STEM (scanning transmission electron microscope) observation results> FIG. 5 shows the observation results showing crystallized products made of "Al-Ni-Zr" compounds.

[0067] FIG. 6 shows the results of observation showing precipitates consisting of "Al-Ti-Zr" compounds.

[0068] In particular, FIG. 5 shows the observation results showing the state after the casting process, and FIG. 6 shows the observation results showing the state after the aging heat treatment carried out after the wire drawing process.

[0069] As shown in Figures 5 and 6, it can be seen that the precipitates made of "Al-Ti-Zr" compounds are finer and more numerous than the precipitates made of "Al-Ni-Zr" compounds. That is, according to the present embodiment, it can be seen that many fine precipitates made of "Al-Ti-Zr" compounds are precipitated in the aluminum alloy wire. And, these many fine precipitates made of "Al-Ti-Zr" compounds can realize an aluminum alloy wire with a well-balanced improvement in tensile strength, elongation characteristics, and electrical conductivity.

[0070] The invention made by the inventor has been specifically described above based on the embodiments thereof, but it goes without saying that the present invention is not limited to the above-described embodiments and can be modified in various ways without departing from the spirit of the invention.

[0071] For example, the aluminum alloy wire may contain, as inevitable impurities, Fe (0.02% by mass or more and 0.15% by mass or less), Si (0.02% by mass or more and 0.15% by mass or less), etc. The aluminum alloy wire may contain Ni (0.1% by mass or more and 1.0% by mass or less), Zr (0.2% by mass or more and 1.0% by mass or less).

[0072] The above embodiment includes the following aspects.

[0073] (Appendix 1) A method for producing an aluminum alloy wire, comprising: a casting step of forming a cast material by casting a molten metal containing aluminum, nickel, zirconium, and titanium, The casting step includes cooling the molten metal from a state in which the temperature of the molten metal is 850°C or higher at a cooling rate that suppresses crystallization of zirconium compounds.

[0074] (Appendix 2) (a) a casting step of forming a casting material by casting a molten metal containing aluminum, nickel, zirconium, and titanium; (b) a wiredrawing step of drawing the cast material to form a drawn wire material; (c) an aging heat treatment step of subjecting the drawn wire material to an aging heat treatment; A method for manufacturing an aluminum alloy wire, comprising: The method for producing an aluminum alloy wire, wherein an aluminum-zirconium compound and an aluminum-titanium-zirconium compound are precipitated by carrying out the aging heat treatment step.

Claims

1. Aluminum and 0.1% by mass or more and 1.0% by mass or less of nickel; 0.2% by mass or more and 1.0% by mass or less of zirconium; 0.05% by mass or more and 0.15% by mass or less of titanium; An aluminum alloy wire containing inevitable impurities, An aluminum alloy wire, including an aluminum-titanium-zirconium compound.

2. The aluminum alloy wire according to claim 1, The aluminum alloy wire has a Ti / Zr ratio, which is a ratio of the concentration of titanium to the concentration of zirconium, of 0.1875 or more and 0.3125 or less.

3. The aluminum alloy wire according to claim 1 or 2, The tensile strength is 175 MPa or more, The conductivity is 55% IACS or more; An aluminum alloy wire having an elongation of 10% or more.

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