Lightweight, high-conductivity, heat-resistant, and iron-containing aluminum wire, and preparation process thereof

Abstract

A lightweight, high-conductivity, heat-resistant, and iron-containing aluminum wire, and a preparation process thereof. The aluminum wire is mainly composed of aluminum, boron, zirconium, iron, lanthanum, and inevitable impurity elements, and the preparation process for the wire is as follows: melting industrial pure aluminum; then adding intermediate alloys of boron, zirconium, iron, and lanthanum to the melt; performing stirring, refining, furnace front component rapid analysis, component adjustment, standing, deslagging, and rapid cooling casting to obtain an aluminum alloy blank; and performing annealing, extrusion, and drawing on the cast blank to obtain an aluminum alloy monofilament. The wire obtained has density less than or equal to 2.714 g/cm3, electrical conductivity greater than or equal to 62% IACS, a short-term heat-resistance temperature as high as 230 C., a long-term heat-resistance temperature as high as 210 C., and tensile strength greater than or equal to 170 MPa.

Claims

1. A lightweight, high-conductivity, heat-resistant, and iron-containing aluminum wire comprising the following components in percentage by weight: B 0.04-0.10 wt. %; Zr 0.10-0.15 wt. %; Fe 0.10-0.20 wt. %; La 0.05-0.30 wt. %; and inevitable titanium, vanadium, chromium, and manganese with a total content less than 0.01 wt. %, and aluminum as the remaining.

2. The lightweight, high-conductivity, heat-resistant, and iron-containing aluminum wire according to claim 1, comprising the following components in percentage by weight: B 0.045-0.095 wt. %; Zr 0.10-0.15 wt. %; Fe 0.10-0.20 wt. %; La 0.05-0.30 wt. %; and inevitable titanium, vanadium, chromium, and manganese with a total content less than 0.01 wt. %, and aluminum as the remaining.

3. The lightweight, high-conductivity, heat-resistant, and iron-containing aluminum wire according to claim 1 wherein during casting, cooling is performed to a room temperature at a rate of 20-300 C./s and then high temperature annealing is performed at 480 C.-500 C. for 1-10 h.

4. The lightweight, high-conductivity, heat-resistant, and iron-containing aluminum wire according to claim 1 wherein the wire has nanoscale spherical Al.sub.3(Er, Zr) composite particles.

5. The lightweight, high-conductivity, heat-resistant, and iron-containing aluminum wire according to claim 4, wherein the nanoscale spherical Al.sub.3(Er, Zr) composite particles are of an L12 structure coherent with a matrix.

6. The lightweight, high-conductivity, heat-resistant, and iron-containing aluminum wire according to claim 1 wherein the wire has density less than or equal to 2.714 g/cm.sup.3, electrical conductivity greater than 62% IACS at 20 C., a short-term heat-resistance temperature as high as 230 C., a long-term heat-resistance temperature as high as 210 C., and tensile strength greater than or equal to 170 MPa.

7. A method for preparing a lightweight, high-conductivity, heat-resistant, and iron-containing aluminum wire, comprising: separately selecting industrial pure aluminum and aluminum-boron, aluminum-zirconium, aluminum-iron and aluminum-lanthanum intermediate alloys according to a designed material component ratio; melting the industrial pure aluminum at 740-780 C.; then adding the intermediate alloys; performing refining and rapid cooling casting to obtain a cast blank; and perform annealing, extrusion, and drawing on the blank to obtain an aluminum alloy monofilament.

8. The method for preparing a lightweight, high-conductivity, heat-resistant, and iron-containing aluminum wire according to claim 7, wherein during the casting, an ingot blank is obtained by common casting or semicontinuous casting; or a rod blank is obtained by continuous casting.

9. The method for preparing a lightweight, high-conductivity, heat-resistant, and iron-containing aluminum wire according to claim 7, wherein during the casting, the cast ingot is cooled to a room temperature at a rate of 20-300 C./s.

10. The method for preparing a lightweight, high-conductivity, heat-resistant, and iron-containing aluminum wire according to claim 9, wherein water-cooling casting is employed during the casting.

11. The method for preparing a lightweight, high-conductivity, heat-resistant, and iron-containing aluminum wire according to claim 8, wherein the ingot blank or the rod blank is subject to the annealing at a temperature of 480 C.-500 C., and is subject to furnace cooling after thermal insulation for 2-10 h.

12. The method for preparing a lightweight, high-conductivity, heat-resistant, and iron-containing aluminum wire according to claim 8, wherein the ingot blank is subject to hot extrusion at a hot extrusion temperature of 300-450 C.; and the rod blank is subject to continuous extrusion at a room temperature.

13. The method for preparing a lightweight, high-conductivity, heat-resistant, and iron-containing aluminum wire according to claim 12, wherein an extrusion ratio for the hot extrusion or the continuous extrusion at the room temperature is greater than or equal to 80, and a total extrusion deformation amount is greater than or equal to 80%.

14. The method for preparing a lightweight, high-conductivity, heat-resistant, and iron-containing aluminum wire according to claim 7, wherein multiple passes of drawing are performed after the extrusion, a coefficient of elongation for the passes being 1.2-1.5 and an accumulative total coefficient of elongation being 5.5-10.5; during the drawing, lubrication and cooling are performed with a common lubricating oil or an emulsion; and a temperature of the aluminum wire is controlled to be less than or equal to 180 C.

15. The method for preparing a lightweight, high-conductivity, heat-resistant, and iron-containing aluminum wire according to claim 14, wherein the prepared wire has density less than or equal to 2.714 g/cm.sup.3, electrical conductivity greater than 62% IACS at 20 C., a short-term heat-resistance temperature as high as 230 C., a long-term heat-resistance temperature as high as 210 C., and tensile strength greater than or equal to 170 MPa.

16. The lightweight, high-conductivity, heat-resistant, and iron-containing aluminum wire according to claim 2, wherein during casting, cooling is performed to a room temperature at a rate of 20-300 C./s and then high temperature annealing is performed at 480 C.-500 C. for 1-10 h.

17. The lightweight, high-conductivity, heat-resistant, and iron-containing aluminum wire according to claim 2, wherein the wire has nanoscale spherical Al.sub.3(Er, Zr) composite particles.

18. The lightweight, high-conductivity, heat-resistant, and iron-containing aluminum wire according to claim 2, wherein the wire has density less than or equal to 2.714 g/cm.sup.3, electrical conductivity greater than 62% IACS at 20 C., a short-term heat-resistance temperature as high as 230 C., a long-term heat-resistance temperature as high as 210 C., and tensile strength greater than or equal to 170 MPa.

19. The method for preparing a lightweight, high-conductivity, heat-resistant, and iron-containing aluminum wire according to any one of claims 8, wherein multiple passes of drawing are performed after the extrusion, a coefficient of elongation for the passes being 1.2-1.5and an accumulative total coefficient of elongation being 5.5-10.5; during the drawing, lubrication and cooling are performed with a common lubricating oil or an emulsion; and a temperature of the aluminum wire is controlled to be less than or equal to 180 C.

20. The method for preparing a lightweight, high-conductivity, heat-resistant, and iron-containing aluminum wire according to any one of claims 9, wherein multiple passes of drawing are performed after the extrusion, a coefficient of elongation for the passes being 1.2-1.5 and an accumulative total coefficient of elongation being 5.5-10.5; during the drawing, lubrication and cooling are performed with a common lubricating oil or an emulsion; and a temperature of the aluminum wire is controlled to be less than or equal to 180 C.

21. The method for preparing a lightweight, high-conductivity, heat-resistant, and iron-containing aluminum wire according to any one of claims 10, wherein multiple passes of drawing are performed after the extrusion, a coefficient of elongation for the passes being 1.2-1.5 and an accumulative total coefficient of elongation being 5.5-10.5; during the drawing, lubrication and cooling are performed with a common lubricating oil or an emulsion; and a temperature of the aluminum wire is controlled to be less than or equal to 180 C.

22. The method for preparing a lightweight, high-conductivity, heat-resistant, and iron-containing aluminum wire according to any one of claims 11, wherein multiple passes of drawing are performed after the extrusion, a coefficient of elongation for the passes being 1.2-1.5 and an accumulative total coefficient of elongation being 5.5-10.5; during the drawing, lubrication and cooling are performed with a common lubricating oil or an emulsion; and a temperature of the aluminum wire is controlled to be less than or equal to 180 C.

23. The method for preparing a lightweight, high-conductivity, heat-resistant, and iron-containing aluminum wire according to any one of claims 12, wherein multiple passes of drawing are performed after the extrusion, a coefficient of elongation for the passes being 1.2-1.5 and an accumulative total coefficient of elongation being 5.5-10.5; during the drawing, lubrication and cooling are performed with a common lubricating oil or an emulsion; and a temperature of the aluminum wire is controlled to be less than or equal to 180 C.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a microstructure morphology of slag of Embodiment 1.

(2) FIG. 2 is an energy spectrum analysis result of a mass point in FIG. 1.

(3) FIG. 3(a) is an SEM photograph of an alloy of comparative example 1.

(4) FIG. 3(b) is an energy spectrum analysis result of a second phase in FIG. 3(a).

(5) FIG. 3(c) is an SEM photograph of an alloy of Embodiment 1.

(6) FIG. 3(d) is an energy spectrum analysis result of a second phase in FIG. 3(c).

(7) FIG. 3(e) is an SEM photograph of an alloy of Embodiment 3.

(8) FIG. 3(f) is an energy spectrum analysis result of a second phase in FIG. 3(e).

(9) FIG. 3(g) is an SEM photograph of an alloy of comparative example 2.

(10) FIG. 3(h) is an energy spectrum analysis result of a second phase in FIG. 3(g).

(11) FIG. 4(a) is a metallograph of a cast structure of an alloy of Embodiment 1.

(12) FIG. 4(b) is a metallograph of a cast structure of an alloy of Embodiment 3.

(13) FIG. 5(a) is a TEM photograph of an alloy of Embodiment 3, in which there is a second phase pinning dislocation.

(14) FIG. 5(b) is a TEM photograph of an alloy of Embodiment 3, in which there is a second phase pinning grain boundary.

(15) FIG. 6 to FIG. 9 are test reports for the performance of a 04 aluminum wire prepared according to Embodiment 3 of the present invention.

DESCRIPTION OF THE EMBODIMENTS

(16) In FIG. 1, a white second phase is an aluminum-iron phase, and at the same time there is a particle which is relatively dark outside and bright white in the middle (as shown by the arrow) in a matrix. An energy spectrum analysis in FIG. 2 shows that the particle is a phase containing aluminum, boron, titanium, and vanadium, which indicates that impurity elements such as titanium and vanadium may react with the boron element to generate a compound which is removed in the form of slag during smelting, thereby improving electrical conductivity of the alloy.

(17) As can be learned from FIG. 3(a) and FIG. 3(b), when a content of boron is 0.035 wt. %, the aluminum-iron phase in the alloy is mainly in the shape of continuous skeletons, and there is a eutectic structure in the shape of laminates. As can be learned from FIG. 3(c) and FIG. 3(d), when a content of boron is 0.04 wt. %, part of the aluminum-iron phase is in the shape of discontinuous short stripes or dots, as indicated by the arrow in FIG. 3(c). As can be learned from FIG. 3(e) and FIG. 3(f), when a content of boron is increased to 0.1 wt. %, the aluminum-iron phase in the alloy is mainly in the form of discontinuous stripes or dots. As can be learned from FIG. 3(g) and FIG. 3(h), when a content of boron is 0.12 wt. %, a large quantity of bulky aluminum-boron phases appears in the alloy.

(18) It can be learned from photographs of cast structures shown in FIG. 4(a) and FIG. 4(b) that in Embodiment 1, a content of an added lanthanum element is relatively low, alloy grains are relatively bulky, and there are many bulky dentritic structures, while in Embodiment 3, a content of an added lanthanum element is relatively high, a grain shape is equiaxed, and grains are obviously refined.

(19) It can be seen from FIG. 5(a) that a large number of dispersively-distributed second phase pinning dislocations are precipitated in an alloy matrix, and it can be learned from FIG. 5(b) that a second phase is pinned, which prevents a grain boundary from moving.

(20) It can be learned from FIG. 6 to FIG. 9 that an aluminum wire prepared according to the present invention has electrical conductivity up to 62% IACS at 20 C., a short-term heat-resistance temperature as high as 230 C. (a tensile strength survival rate after heating for 1 h at 230 C. is up to 91%), and tensile strength of 170 MPa, which may serve as a forceful supportive proof for the advancement and superiority of the present invention.

(21) Embodiments of the Present Invention

(22) Implementations of the Present Invention

(23) Comparative Example 1

(24) An industrial pure aluminum ingot with purity higher than 99.7%, an Al-2.5% B intermediate alloy, an Al-11.34% Zr intermediate alloy, an Al-31.48% La intermediate alloy, and an Al-9.33% Fe intermediate alloy are used as raw materials; the industrial pure aluminum is first melt at 760 C.; then the aluminum-boron intermediate alloy, the aluminum-zirconium intermediate alloy, the aluminum-lanthanum intermediate alloy, and the aluminum-iron intermediate alloy are added; and percentages by weight of the elements are made to be: 0.035 wt. % for boron, 0.10 wt. % for zirconium, 0.09 wt. % for lanthanum, and 0.10 wt. % for iron. After the intermediate alloys are completely melt, a temperature of the melt is decreased to 740 C. and thermal insulation is performed. A supersaturated solid-dissolved aluminum alloy cast blank is then obtained by stirring, refining, furnace front component rapid analysis, component adjustment, standing, and deslagging, as well as rapid cooling casting. The blank is subject to furnace cooling after annealed at 480 C. for 10 h, and then to hot extrusion at 400 C. at an extrusion ratio of 89.7 and an extrusion deformation amount of 98.7%, to obtain a 9.5 round aluminum rod, which is subject to multiple passes of drawing to obtain a 4.0 mm aluminum alloy monofilament. Performance of the monofilament is tested, with results shown in Table 1.

(25) TABLE-US-00001 TABLE 1 Indicators for Overall Performance of the Aluminum Monofilament of Comparative Example 1 Strength survival Strength survival Electrical Tensile rate after rate after Density conductivity strength annealing at 230 annealing at 210 (g/cm.sup.3) (% IACS) (MPa) C. for 1 h (%) C. for 400 h (%) 2.710 59.5 165 86.5 87.1

(26) Embodiment 1

(27) An industrial pure aluminum ingot with purity higher than 99.7%, an Al-2.5% B intermediate alloy, an Al-11.34% Zr intermediate alloy, an Al-31.48% La intermediate alloy, and an Al-9.33% Fe intermediate alloy are used as raw materials; the industrial pure aluminum is first melt at 760 C.; then the aluminum-boron intermediate alloy, the aluminum-zirconium intermediate alloy, the aluminum-lanthanum intermediate alloy, and the aluminum-iron intermediate alloy are added; and percentages by weight of the elements are made to be: 0.04 wt. % for boron, 0.10 wt. % for zirconium, 0.09 wt. % for lanthanum, and 0.10 wt. % for iron. After the intermediate alloys are completely melt, a temperature of the melt is decreased to 740 C. and thermal insulation is performed. A supersaturated solid-dissolved aluminum alloy cast blank is then obtained by stirring, refining, furnace front component rapid analysis, component adjustment, standing, and deslagging, as well as rapid cooling casting. The blank is subject to furnace cooling after annealed at 480 C. for 10 h, and then to hot extrusion at 400 C. at an extrusion ratio of 89.7 and an extrusion deformation amount of 98.7%, to obtain a 9.5 round aluminum rod, which is subject to multiple passes of drawing to obtain a 4.0 mm aluminum alloy monofilament. Performance of the monofilament is tested, with results shown in Table 2. Electrical conductivity, tensile strength, and heat resistance are all improved when compared to comparative example 1.

(28) TABLE-US-00002 TABLE 2 Indicators for Overall Performance of the Aluminum Monofilament of Embodiment 1 Strength survival Strength survival Electrical Tensile rate after rate after Density conductivity strength annealing at 230 annealing at 210 (g/cm.sup.3) (% IACS) (MPa) C. for 1 h (%) C. for 400 h (%) 2.713 62.1 170 90.5 91.1

(29) Embodiment 2

(30) An industrial pure aluminum ingot with purity higher than 99.7%, an Al-2.5% B intermediate alloy, an Al-11.34% Zr intermediate alloy, an Al-31.48% La intermediate alloy, and an Al-9.33% Fe intermediate alloy are used as raw materials; the industrial pure aluminum is first melt at 760 C.; then the aluminum-boron intermediate alloy, the aluminum-zirconium intermediate alloy, the aluminum-lanthanum intermediate alloy, and the aluminum-iron intermediate alloy are added; and percentages by weight of the elements are made to be: 0.07 wt. % for boron, 0.15 wt. % for zirconium, 0.19 wt. % for lanthanum, and 0.20 wt. % for iron. After the intermediate alloys are completely melt, a temperature of the melt is decreased to 740 C. and thermal insulation is performed. A supersaturated solid-dissolved aluminum alloy cast blank is then obtained by stirring, refining, furnace front component rapid analysis, component adjustment, standing, and deslagging, as well as rapid cooling casting. The blank is subject to furnace cooling after annealed at 490 C. for 8 h, and then to hot extrusion at 400 C. at an extrusion ratio of 89.7 and an extrusion deformation amount of 98.7%, to obtain a 9.5 round aluminum rod, which is subject to multiple passes of drawing to obtain a 4.0 mm aluminum alloy monofilament. Performance of the monofilament is tested, with results shown in Table 3.

(31) TABLE-US-00003 TABLE 3 Indicators for Overall Performance of the Aluminum Monofilament of Embodiment 2 Strength survival Strength survival Electrical Tensile rate after rate after Density conductivity strength annealing at 230 annealing at 210 (g/cm.sup.3) (% IACS) (MPa) C. for 1 h (%) C. for 400 h (%) 2.711 62.5 175 90.8 91.7

(32) Embodiment 3

(33) An industrial pure aluminum ingot with purity higher than 99.7%, an Al-2.5% B intermediate alloy, an Al-11.34% Zr intermediate alloy, an Al-31.48% La intermediate alloy, and an Al-9.33% Fe intermediate alloy are used as raw materials; the industrial pure aluminum is first melt at 760 C.; then the aluminum-boron intermediate alloy, the aluminum-zirconium intermediate alloy, the aluminum-lanthanum intermediate alloy, and the aluminum-iron intermediate alloy are added; and percentages by weight of the elements are made to be: 0.095 wt. % for boron, 0.15 wt. % for zirconium, 0.29 wt. % for lanthanum, and 0.20 wt. % for iron. After the intermediate alloys are completely melt, a temperature of the melt is decreased to 740 C. and thermal insulation is performed. A supersaturated solid-dissolved aluminum alloy cast blank is then obtained by stirring, refining, furnace front component rapid analysis, component adjustment, standing, and deslagging, as well as rapid cooling casting. The blank is subject to furnace cooling after annealed at 500 C. for 2 h, and then to hot extrusion at 400 C. at an extrusion ratio of 89.7 and an extrusion deformation amount of 98.7%, to obtain a 9.5 round aluminum rod, which is subject to multiple passes of drawing to obtain a 4.0 mm aluminum alloy monofilament. Performance of the monofilament is tested, with results shown in Table 4.

(34) TABLE-US-00004 TABLE 4 Indicators for Overall Performance of the Aluminum Monofilament of Embodiment 3 Strength survival Strength survival Electrical Tensile rate after rate after Density conductivity strength annealing at 230 annealing at 210 (g/cm.sup.3) (% IACS) (MPa) C. for 1 h (%) C. for 400 h (%) 2.714 62 170 91 92.3

(35) Comparative Example 2

(36) An industrial pure aluminum ingot with purity higher than 99.7%, an Al-2.5% B intermediate alloy, an Al-11.34% Zr intermediate alloy, an Al-31.48% La intermediate alloy, and an Al-9.33% Fe intermediate alloy are used as raw materials; the industrial pure aluminum is first melt at 780 C.; then the aluminum-boron intermediate alloy, the aluminum-zirconium intermediate alloy, the aluminum-lanthanum intermediate alloy, and the aluminum-iron intermediate alloy are added; and percentages by weight of the elements are made to be: 0.12 wt. % for boron, 0.15 wt. % for zirconium, 0.29 wt. % for lanthanum, and 0.20 wt. % for iron. After the intermediate alloys are completely melt, a temperature of the melt is decreased to 740 C. and thermal insulation is performed. A supersaturated solid-dissolved aluminum alloy ingot blank is then obtained by stirring, refining, furnace front component rapid analysis, component adjustment, standing, and deslagging, as well as rapid cooling casting. The blank is subject to furnace cooling after annealed at 500 C. for 2 h, and then to hot extrusion at 400 C. at an extrusion ratio of 89.7 and an extrusion deformation amount of 98.7%, to obtain a 9.5 round aluminum rod, which is subject to multiple passes of drawing to obtain a 4.0 mm aluminum alloy monofilament. Performance of the monofilament is tested, with results shown in Table 5.

(37) TABLE-US-00005 TABLE 5 Indicators for Overall Performance of the Aluminum Monofilament of Comparative Example 2 Strength survival Strength survival Electrical Tensile rate after rate after Density conductivity strength annealing at 230 annealing at 210 (g/cm.sup.3) (% IACS) (MPa) C. for 1 h (%) C. for 400 h (%) 2.715 60.2 175 90.1 90.9

(38) A content of boron in comparative example 1 is 0.035 wt. %, and it can be learned from FIG. 3(a) and FIG. 3(b) that a second phase in the alloy exists mainly in the shape of continuous skeletons, with corresponding electrical conductivity being 59.5% IACS. A content of boron in Embodiment 1 is 0.04 wt. %, and it can be learned from FIG. 3(c) and FIG. 3(d) that part of a second phase is in the shape of discontinuous short stripes or dots (as shown by the arrow in the figure), with corresponding electrical conductivity being 62.1% IACS. It indicates that an obvious effect for improving the electrical conductivity appears only after the content of boron reaches a certain value. A content of boron in Embodiment 3 is 0.095 wt. %, and it can be learned from FIG. 3(g) and FIG. 3(h) that an aluminum-iron phase in the alloy exists mainly in the form of discontinuous stripes or dots, with corresponding electrical conductivity being 62% IACS. A content of boron in comparative example 2 reaches 0.12 wt. %, and it can be learned from FIG. 3(g) and FIG. 3(h) that many bulky aluminum-boron phases are generated in the alloy, with corresponding electrical conductivity being 60.2% IACS. It indicates that an excessively high content of boron causes a decrease in the electrical conductivity.

(39) In summary, the aluminum alloy wires obtained according to the three embodiments of the present invention all have density lower than or equal to 2.714 g/cm.sup.3, electrical conductivity greater than or equal to 62% IACS at a room temperature of 20 C., a short-term heat-resistance temperature as high as 230 C. (the strength survival rate after annealing at 230 C. for 1 hour is greater than 90%), and a long-term heat-resistance temperature as high as 210 C. (the strength survival rate after annealing at 210 C. for 400 hours is greater than 90%). The components added in comparative example 1 are the same as those in Embodiment 1, except a smaller quantity of added born elements, and the components added in comparative example 2 are the same as those in Embodiment 3, except a higher content of added boron. However, the electrical conductivity in each of the two comparative examples is lower than 61% IACS, and in comparative example 1, the strength survival rate after annealing at 230 C. for 1 hour is only 86.5%, and the strength survival rate after annealing at 210 C. for 400 hours is only 87.1%.