WO2002044432A1 - Creep resistant cable wire - Google Patents

Abstract

A low creep electrical conducting aluminum cable wire alloy is provided. The wire alloy has about 0.07 to about 0.12 weight percent iron, about 0.04 to about 0.07 weight percent silicon, about 0.03 to about 0.08 weight percent zirconium, and a balance weight percent of aluminum.

Description

CREEP RESISTANT CABLE WTRE

RELATED APPLICATION

The present application is a based on and claims priority to U.S. Provisional Patent Application Serial No. 60/250, 169, filed November 30, 2000, entitled "HIGH TEMPERATURE LOW CREEP CABLE WIRE." To the extent not included below, the subject matter disclosed in this application is hereby expressly incorporated into the present application.

FIELD OF THE INVENTION

The present invention relates to aluminum-based alloys for use as electrical conductors in the form of wire cable, and more particularly, to power transmission cable wire made from creep resistant aluminum alloys.

BACKGROUND AND SUMMARY

Electrical Grade (EC) aluminum conductors have been utilized as overhead cables or power transmission lines since the 1920's. When power transmission lines are strung between transmission towers, the lines are intended to suspend a certain height off of the ground. This height is often determined by a desired amount of clearance that is necessary for the location that the transmission line is strung. For example, if the line is being strung across a highway, the lines must be high enough from the ground to provide sufficient clearance for tall vehicles. Similarly, if the transmission lines are being strung across large areas of terrain, the lines should be high enough to clear any foliage. And in general, all such transmission lines should be high enough and out of general public reach for obvious safety reasons.

Creep, however, can be a detrimental effect of such strung transmission lines. Creep is plastic deformation that occurs in metal at stresses below its yield strength. Typically, metal that is stressed below its yield point for a short time or as part of normal deformation will return to its original shape and size by virtue of its elasticity. When the time period is sufficiently long or the temperature excessively high, however, permanent plastic deformation can occur. The extent of which creep is a factor with such transmission lines is a function of the properties of the metal used, applied stress, temperature and time under load. The effects of creep can be mitigated by, among other methods, the composition of the metal used for the conductor. For conventional modern power lines, typically, 6000 series aluminum alloys are used. Cable manufacturers often supply sag and tension data that include the effects of creep. It is known, however, that such alloys are affected by high temperatures, i.e., temperatures in excess of their artificial aging temperature, which is normally about 150 degrees C. It is also known that once these alloys are exposed to temperatures close to or in excess of their artificial aging temperature, the tensile strength of the alloy decreases, which, in turn, impacts other properties of the cable.

Other cable types, such as aluminum conductor steel reinforced (ACSR), all aluminum conductor (AAC), aluminum conductor alloy reinforced (ACA ), all aluminum alloy conductor (AAAC), etc. of a variety of sizes, are rated for a certain "current carrying capacity." These ratings are consulted when choosing an electrical cable for a particular application. Such ratings are necessary because the current carrying capacity is limited for each size wire due to overloading the cable, resulting in the loss of physical properties, i.e., tensile strength. As the aforementioned annealing lowers the tensile strength of the cable, the potential for creep to occur increases which, thus, causes the cable to sag.

Running electrical power through power lines is essentially a cyclical heating and cooling effect or annealing of the wires. This annealing may cause the tensile strength of the cable to creep sag. And once the tensile strength properties have been altered, the effect is generally irreversible. Since the 1920's, aluminum conductor technology has experienced considerable transformation including the use of steel core wire for the cable, as well as high strength metal alloys, to improve its resistance to creep by improving the metal's resistance to overloading. It is such overloading that is known to increase the temperature of the cable, thereby causing the creep effect. The current solution to this problem is heat resistant alloys, specifically, "high strength" aluminum alloys. Such alloys normally have 1.5 to 2 times higher tensile strength than that of EC grade alloy wire. This high strength is often the result of the addition of zirconium. Zirconium is used because it is known to retard the "stress relieving" of alloys at temperatures that are normally in excess of the performance capabilities of traditional EC aluminum. The detriment of using zirconium is that the conductivity of such wires can be as low as 50 percent of the International Annealed Copper Standard (LACS), well below the conductivity of EC wire which is about 62 percent LACS. Specifically, it is estimated that for each 0.1 weight percent zirconium added to an alloy, the conductivity lowers about 4 percent LACS.

Because zirconium is known to retard the effects of temperature on aluminum alloys, but also lower conductivity, a new approach to reduce creep would be beneficial. Because trace elements can be detrimental to conductivity, one illustrative approach is to use a prime metal having very small amounts of trace elements, like high purity, commercial grade aluminum, for example. Another illustrative approach is to use alloying elements that increase strength or have resistance to creep, yet, have a less detrimental impact on conductivity. A third approach is to balance the first and second approaches by using high purity aluminum with particular alloying elements to reduce the effects of creep without reducing the conductivity to unacceptable levels.

This illustrative approach deviates from the commonly known solution of high strength, high zirconium content wires to reduce creep. For example, high purity "prime metal," of about 99.7 to 99.8 percent pure aluminum wire having an iron content of less than about 0.10 weight percent and a silicon content of less than about 0.06 weight percent, provided good conductivity. Alloying elements, such as boron, in the form of 5 percent master alloy or any commercial boron master alloy can be used to control the titanium, vanadium, and chromium (i.e., trace elements) to maintain conductivity. The additions of boron can be calculated based on the levels of titanium, vanadium, and manganese present in the wire metal. Controlling these elements minimizes the possibility of excessive work hardening during the wire drawing process, while still facilitating the highest possible conductivity. The result is maintaining similar tensile strength properties of EC grade material while subjecting the cables to excessive temperatures for several hours. Accordingly, the present disclosure provides a low creep electrical conducting aluminum cable wire alloy. The wire alloy comprises about 0.07 to about 0.12 weight percent iron, about 0.04 to about 0.07 weight percent silicon, about 0.03 to about 0.08 weight percent zirconium, and a balance weight percent of aluminum. Further illustrative embodiments may include about 0.02 weight percent of cerium, about 0.03 to about 0.06 weight percent zirconium, about 0.005 weight percent boron, and about 0.04 to about 0.05 weight percent misch metal. The misch metal may further comprise about 50 weight percent cerium, about 25 weight percent lanthanum, about 18 percent neodymium and about 8 percent praseodymium. Another embodiment provides a low creep cable wire alloy comprising an aluminum alloy. The aluminum alloy comprising about 99.8 weight percent pure aluminum and has an effective amount of iron, silicon and zirconium to produce a tensile strength of greater than about 18 kg/mm² and a conductivity of about 60 percent IACS in an environment of 150 degrees C for about 100 hours. Wherein the effective amount of iron is about 0.12 weight percent and below, the effective amount of silicon is about 0.07 weight percent and below, and the effective amount of zirconium is about 0.08 weight percent and below. Further embodiments may include from about 0.0015 to about 0.005 weight percent boron.

Another embodiment provides a low creep cable wire alloy comprising an aluminum conductor having an effective amount of iron, silicon, zirconium and cerium to produce a tensile strength of greater than about 16 kg/mm² and a conductivity of about 59.0 to 60.0 percent IACS after being subject to an environment of 200 degrees C for 100 to 500 hours. The effective amount of iron is about 0.12 weight percent and below, the effective amount of silicon is about 0.07 weight percent and below, the effective amount of zirconium is about 0.08 weight percent and below, and the effective amount of cerium is about 0.025 weight percent. Further embodiments may include the aluminum conductor being at least about 99.8 weight percent pure aluminum prior to alloying. Furthermore the alloy may comprise from about 0.0015 to about 0.002 weight percent boron. Another embodiment may provide a low creep electrical conducting aluminum alloy comprising about 0.025 to about 0.075 weight percent zirconium, about 0.015 to about 0.035 weight percent cerium, less than about 0.14 weight percent iron, less than about 0.08 weight percent silicon, less than about 0.004 weight percent trace elements, less than about 0.003 weight percent boron, and a balance weight percent of aluminum. Further embodiments may comprise the aluminum conductor is at least about 99.7 weight percent pure aluminum, the misch metal comprising about 0.015 to about 0.035 weight percent cerium, and wherein trace elements are titanium, vanadium, and chromium.

Another embodiment may provide a low creep electrical conducting aluminum alloy comprising about 0.030 to about 0.070 weight percent zirconium, about 0.018 to about 0.030 weight percent cerium, less than about 0.10 weight percent iron, less than about 0.06 weight percent silicon, less than about 0.003 weight percent trace elements, less than about 0.002 weight percent boron, and a balance weight percent of aluminum. A low creep electrical conducting aluminum alloy comprising about 0.025 to about 0.075 weight percent zirconium, less than about 0.14 weight percent iron, less than about 0.08 weight percent silicon, less than about 0.004 weight percent trace elements, less than about 0.003 weight percent boron, and a balance weight percent of aluminum.

Additional features and advantages of the cable wire will become apparent to those skilled in the art upon consideration of the following detailed description of the several embodiments exemplifying the best mode of carrying out the invention as presently perceived.

BRIEF DESCRIPTION OF THE DRAWINGS

Particular testing results, for the illustrative compositions described herein, are referenced by the attached drawings, in which: Figure 1 is a chart of the wire tension strength results for the EC and

LC wires after aging for 500 hours; and

Figure 2 is a chart of the cable breaking load results for the EC and LC cables.

The exemplification set out herein illustrates selected testing results and is not to be construed as limiting the scope of the invention in any manner. DETAILED DESCRIPTION

Illustrative embodiments of low creep alloy cable wire (hereinafter "LC alloy" wire) 1 through 5, each of a unique composition, are shown in Table 1. It is contemplated that such wires in plurality form comprise the transmission line cable of the present invention. The accompanying tensile strength and conductivity test data illustrates that the effects of exposure to evaluated temperatures on "LC" wires is less prevalent when compared to the conventional EC wire. For example, the LC alloy wires exhibit a tensile strength of between 18.86 and 19.5 kg/mm², and maintain conductivity between 59.4 and 60.9 during an aging test of 100 hours at 150 degrees C. Even more pronounced were the tensile strengths and conductivities of the LC alloy wires aged for 100 hours at 200 degrees C. (See Table 1.) Specifically, the tensile strength of the LC alloy wires ranged from 16.92 to 17.84 kg/mm², and a conductivity of 59.9 to 60.6 IACS. In contrast, the EC wire exhibited a tensile strength of only 14.58 kg/mm². Thus, as shown in Table 1, the LC alloy wires maintain a higher tensile strength, and are more creep resistant, particularly at higher than normal temperatures, than the conventional EC wire. In addition, because the LC alloy wires maintained tensile strength, rather than lost tensile strength, these wires are distinguishable from traditional high strength wires to the extent LC wires are not required to be such a comparatively large gauge. High strength wires tend to form large "circular mill area" cables and tend to lose strength in high temperature environments. But even with such a loss, the effects still tend to be less than the effects to EC wire. It is noted that, although LC alloys 1 and 2 were not tested at 200 degrees C, it is believed that, consistent with their behavior at 150 degrees C and the behavior of LC alloys 3 through 5 tested at 200 degrees C, LC alloys 1 and 2 will maintain tensile strength while also maintaining conductivity at elevated temperatures. TABLE 1

ALLOY TENSILE STRENGTH AND CONDUCTIVITY COMPARISON

As Drawn 100 hours (5)150 C 100 hours @ 200 C

Tensile

Tensile Tensile Conductivit

Conductivity Conductivity Strength

Strength Strength

Alloy % IACS % IACS kg/mm² y kg/mm² kg/mm² % IACS

EC 19.78 62.0 19.67 62.0 14.58 62.4

LC I 19.16 60.3 19.50 60.9 — —

LC 2 19.47 59.7 18.96 60.7 — —

LC 3 19.67 60.0 18.86 59.8 16.92 60.4

LC 4 19.88 59.4 19.47 59.4 17.74 59.9

LC 5 19.06 59.5 18.86 59.7 16.72 60.6

In addition to the other four LC compositions, LC alloy 4 exhibited particularly unexpected results, having over-all properties that maintained a tensile strength of 17.74kg/mm² while also maintaining a conductivity of 59.9 percent IACS at an accelerated condition of 200 degrees C for 100 hours. Again, this is in contrast to the EC wire which maintained a tensile strength of only 14.58 kg/mm², with a conductivity of 62.4 percent IACS under the same conditions. Such a reduced tensile strength of the EC wire will not be enough to retard creep of a suspended cable. Accordingly, it is expected that while an EC conductor can carry 1000 amps, for example, maintaining an ambient temperature of less than 50 degrees C, a LC alloy wire of the same size can withstand a current increase of up to about 70 percent. The operating temperature of the LC alloy wire can, therefore, increase to about 390 degrees F, and yet, not be significantly affected, even over an extended period of time. An illustrative embodiment of the LC alloy wire comprises a "high purity" commercial aluminum. Again, it is contemplated that the physical properties of the base alloy may not be appreciably different from the EC wire under moderate conditions, depending on the quality of that wire. Such high quality, high purity commercial aluminum is about 97.7 or greater weight percent pure aluminum, having a conductivity of about 61.5 percent IACS or above with an iron content of about 0.10 to 0.17 weight percent, a silicon content of about 0.07 weight percent, and trace elements totaling less than about 0.04 weight percent. Additions of zirconium can be made within a range of about 0.03 to about 0.08 weight percent, and the addition of "misch metal" can be within a range of about 0.04 to about 0.05 weight percent. Furthermore, the control of certain trace elements may be achieved by introducing boron. Illustratively, the alloy may maintain a presence of titanium or vanadium at a level less than about 0.0015 weight percent, while maintaining the boron level at less than about 0.0015. The less titanium and vanadium, the less resistance the wire will have. It is contemplated that the misch metal present may comprise about 50 percent cerium, 25 percent lanthanum, 18 percent neodymium, and 8 percent praseodymium. It is further contemplated that, in other embodiments, small additions of boron may produce beneficial effects on the performance of the wire by increasing the wires conductivity. In addition, as further discussed herein, cerium can have beneficial effects on the LC alloys. The compositions of such illustrative embodiment alloys, as compared with EC wire, are shown in Table 2.

TABLE 2

ALLOY COMPOSITION

Weight Percent

Heat (Alloy) Fe Si Zr Ce

EC 0.140 0.050 0.004 —

LC I 0.085 0.044 0.034 —

LC 2 0.118 0.062 0.031 —

LC 3 0.089 0.055 0.051 —

LC 4 0.087 0.047 0.062 0.025

LC 5 0.076 0.045 0.060 0.025

The balance bein g high purity aluminum

The several embodiments of the LC aluminum alloy cable wires are made from a continuous casting and rolling process wherein the aluminum is charged into a furnace where it is alloyed, adjusted for temperature, chemical analysis performed, cast, degassed, and finally rolled and coiled. Specifically, the process comprises, first, selecting an aluminum base metal with aluminum purity of at least about 99.75 percent. This selection is also predicated on the amounts of iron and silicon present, as well as the amount of the trace elements normally contained in commercial "electrical grade" aluminum. Conventionally, such aluminum is provided from a "smelter" either in molten form or in ingots. In molten form, the aluminum is about 780 degrees C, and can be quickly transported from the smelter to the furnace and rod mill area via crucibles. Alternatively, however, if the smelter is not close to the furnace, the metal can be poured into "ingot" molds and allowed to solidify. Once the ingots are cooled, they can then be transported to the furnace and re-melted.

After the crucibles are filled with molten aluminum, the molten metal is boron treated while still in their crucibles. The boron precipitates the titanium, vanadium, and chromium trace elements. The amount of boron added is based on the total trace elements in the aluminum. For example, each crucible is treated with about 5 percent boron/95 percent aluminum master alloy. The boron additions are based on the total amount of trace elements of each crucible of aluminum to precipitate those trace elements (e.g., titanium, vanadium, and chromium). The amount is controlled, however, in an effort to prevent an excess of boron affecting the alloying of zirconium because it can be precipitated in the same manner as the other trace elements. The zirconium master alloy is then introduced to the molten metal. The zirconium master alloy comprises about 5.7 percent zirconium, 0.11 percent iron, 0.06 percent silicon, 0.05 percent titanium, 0.3 percent other, and aluminum as the balance. Only about 60 percent of the zirconium master alloy addition, however, is placed in the well portion of the furnace before the molten metal is deposited therein. The misch metal is also added in the well of the furnace prior to pouring the molten metal therein for LC alloys 4 and 5. This procedure helps assure minimum cerium losses due to "burn-off (i.e., rapid oxidation). Illustratively, the misch metal comprises about 50 percent cerium, 20 to 25 percent lanthanum, 15 to 20 percent neodymium, and about 5 to 10 percent praseodymium.

After these treatments, the molten metal in each crucible is poured into the well of the furnace, typically, through a metal charging spout. The remaining 40 percent of the zirconium master alloy is added to the molten metal while it is pouring from the crucible. The molten metal is allowed to settle for a period of time (about 30 minutes), as well as the temperature maintained high enough to support the continuous casting process. The actual furnace temperature is adjusted so that the molten metal arrives at the casting point of about 680 to 700 degrees C. The molten metal in the furnace is also stirred prior to retrieving the final chemical composition samples to assure a homogeneous melt (all elements distributed through the furnace), and confirm that the zirconium addition is within the desired level. Spectro graph samples are taken of the alloy at several locations throughout the furnace. Readings from these locations help assure that a homogeneous distribution of alloying elements are maintained throughout the furnace. It is appreciated that additional elements or alloys can be added for the purpose of achieving a desired chemical composition. All chemical analysis, except cerium, was performed utilizing an optical spectrometer. Due to the limitations of existing analytical equipment, the cerium was analyzed on an atomic absorption unit.

The molten metal is then delivered into a continuous casting machine for casting the bar stock. A continuous casting machine solidifies the molten metal in a bar form and is then conveyed to the rolling mill, which rolls the bar into a rod. The continuous casting machine is of conventional casting wheel/belt type, having a casting wheel with a casting groove in its periphery which is partially closed by a steel belt supported by the casting wheel and an idler pulley. The casting wheel and the belt cooperate to provide a mold into one end of which the cast bar is emitted in substantially that condition in which it solidified. The casting wheel assures that the metal's solidification rate is maintained in a manner that also assures that the alloying elements are partially "out of a supersaturated solution." A solid cast bar temperature is maintained at a temperature within a range of 450 to 500 degrees C, preferably within a range of 470 to 485 degrees C. The metal solidification is controlled by making fine adjustments in the application of cooling water. Additional cooling is added to the "belt" side of the bar. The addition of the cool water allows solidification to be altered in an effort to retard solidification of the alloy during the casting.

Prior to casting, the molten metal passes through a degassing unit, which removes hydrogen gas from the molten metal. Degassing units are normally utilized in most aluminum casting facilities, though not required to cast aluminum.

After casting, the bar stock is conveyed to the rolling mill. The rolling mill is of conventional type, having a plurality of roll stands arranged to hot-form the cast bar by a series of deformations. The continuous casting machine and the rolling mill are positioned relative to each other so that the cast bar enters the rolling mill substantially immediately after solidification and in substantially that condition in which it solidified. In this condition, the cast bar is at a hot-forming temperature within the range of temperatures for hot-forming the cast bar. Roll stands each include a plurality of rolls which engage the cast bar. Illustratively, pairs of rolls are arranged diametrically opposite from one another or arranged at equally spaced positions about the axis of movement of the cast bar through the rolling mill. The rolls of each roll stand are rotated at a predetermined speed. The rolling mill serves to hot-form the cast bar into a rod of a cross-sectional area less than that of the cast bar as it enters the rolling mill. Peripheral surfaces of the rolls of adjacent roll stands in the rolling mill change in configuration; that is, the cast bar is engaged by the rolls of successive roll stands with surfaces of varying configurations, and from different directions. This varying surface engagement of the cast bar in the roll stands functions to knead or shape the metal in the cast bar in such a manner that it is worked at each roll stand, and also to simultaneously reduce and change the cross-sectional area of the cast bar into that of the rod for further processing, i.e., wire drawing. During the rolling process, the control of emulsion temperature, concentration, and flow is maintained to assure the rod properties are maintained within a predetermined range. This "predetermined range" may vary due to the influence of wire diameter (i.e., work hardening during wire drawing). An illustrative predetermined range is a tensile strength of about 12 kg/mm² and a conductivity of about 59+ to 60+ percent IACS. In such a case, the wire can maintain a tensile strength higher than expected after being subjected to a 500 hour aging at 200 degrees C. Because a continuous rod is produced, it is coiled for space and transport considerations.

Further understanding of the invention will be appreciated by the following non-limiting examples.

EXAMPLE: LC Alloy 1

Samples A through D of the LC alloy 1 composition were made according to the process described above. For this example 7,240 kg of 97.5 plus percent commercially pure molten aluminum metal was used, with 6 ingots (36 kg) of 6 percent zirconium master alloy added through the metal charging spout. Tables 3 and 4 below show the resulting chemical composition of four samples drawn from the furnace, as well as the composition of sample cast rods. Spectrograph analysis shows a slight variation in composition between the molten alloy and the cast rods. Such variations, however, are within acceptable tolerance. The composition of samples A, B, C, and D in both molten and rod form were taken from various locations in the furnace or along the coil, respectively, to confirm homogeneous alloying during production. The parameters described above, and testing described further herein, were done so in a "production atmosphere," rather than a laboratory environment, which accounts for the minor variations in procedures and results which is appreciated by one skilled in the art. It is further appreciated that because of such a large scale production environment, the compositions of LC alloy 1, as well as all the other LC alloys, should not be considered limited to the precise readings to the four significant figures.

The LC alloy 1 contained an average of about 0.0338 weight percent zirconium, with 0.0443 weight percent silicon, 0.0838 weight percent iron, and minimum amount trace elements in melt form, and about 0.0337 weight percent zirconium, with 0.0443 weight percent silicon, and 0.0851 weight percent iron in rod form.

TABLE 3

LC alloy 1 CHEMICAL COMPOSITION (MOLTEN ALLOY)

Weight Percent

Sample Si Fe Cu Mn Mg Cr Ni

A 0.0440 0.0820 0.0012 0.0039 0.0003 0.0000 0.0041

B 0.0440 0.0840 0.0011 0.0040 0.0003 0.0000 0.0042

C 0.0440 0.0840 0.0012 0.0040 0.0003 0.0001 0.0042

D 0.0450 0.0850 0.0011 0.0040 0.0003 0.0003 0.0043

Average 0.0443 0.0838 0.0012 0.0040 0.0003 0.0001 0.0042

Sample Zn Ti V Pb Sn B Be

A 0.0151 0.0009 0.0000 0.0018 0.0000 0.0004 0.0000

B 0.0153 0.0010 0.0000 0.0022 0.0006 0.0005 0.0000

C 0.0158 0.0015 0.0016 0.0022 0.0007 0.0013 0.0000

D 0.0158 0.0010 0.0000 0.0024 0.0008 0.0006 0.0000

Average 0.0155 0.0011 0.0004 0.0022 0.0005 0.0007 0.0000

Sample Ga Zr Cd Na Ca Li

A 0.0143 0.0337 0.0000 0.0003 0.0000 0.0001

B 0.0143 0.0339 0.0011 0.0002 0.0000 0.0001

C 0.0141 0.0338 0.0011 0.0003 0.0000 0.0001

D 0.0143 0.0337 0.0011 0.0002 0.0000 0.0001

Average 0.0143 0.0338 0.0008 0.0003 0.0000 0.0001 TABL E 4

LC alloy 1 CHEMICAL COMPOSITION (CAST ROD)

Weight Percent

Coil

Si Fe Cu Mn Mg Cr Ni Number

1 0.0430 0.0840 0.0013 0.0040 0.0003 0.0000 0.0041

2 0.0430 0.0830 0.0011 0.0040 0.0002 0.0000 0.0041

3 0.0450 0.0860 0.0014 0.0039 0.0003 0.0000 0.0042

4 0.0450 0.0880 0.0017 0.0040 0.0002 0.0000 0.0042

5 0.0450 0.0850 0.0011 0.0040 0.0002 0.0000 0.0042

6 0.0440 0.0850 0.0019 0.0040 0.0002 0.0000 0.0042

7 0.0450 0.0880 0.0015 0.0040 0.0002 0.0003 0.0043

8 0.0440 0.0810 0.0013 0.0040 0.0002 0.0000 0.0041

9 0.0450 0.0860 0.0022 0.0040 0.0002 0.0001 0.0042

Average 0.0443 0.0851 0.0015 0.0040 0.0002 0.0000 0.0042

Coil

Zn Ti V Pb Sn B Be

Number

1 0.0152 0.0009 0.0000 0.0020 0.0006 0.0005 0.0000

2 0.0153 0.0010 0.0000 0.0021 0.0006 0.0005 0.0000

3 0.0156 0.0008 0.0000 0.0021 0.0003 0.0006 0.0000

4 0.0159 0.0010 0.0000 0.0022 0.0007 0.0006 0.0000

5 0.0154 0.0011 0.0000 0.0021 0.0003 0.0009 0.0000

6 0.0161 0.0012 0.0000 0.0022 0.0006 0.0008 0.0000

7 0.0161 0.0011 0.0000 0.0024 0.0007 0.0008 0.0000

8 0.0152 0.0010 0.0000 0.0018 0.0000 0.0005 0.0000

9 0.0170 0.0011 0.0000 0.0023 0.0007 0.0007 0.0000

Average 0.0158 0.0010 0.0000 0.0021 0.0005 0.0007 0.0000

Coil

Ga Zr Cd Na Ca Li

Number

1 0.0135 0.0333 0.0011 0.0001 0.0000 0.0000

2 0.0135 0.0332 0.0011 0.0001 0.0000 0.0000

3 0.0140 0.0336 0.0006 0.0002 0.0000 0.0000

4 0.0140 0.0337 0.0011 0.0002 0.0000 0.0001

5 0.0140 0.0340 0.0011 0.0000 0.0000 0.0001

6 0.0139 0.0344 0.0011 0.0002 0.0000 0.0001

7 0.0140 0.0340 0.0011 0.0002 0.0000 0.0001

8 0.0139 0.0338 0.0000 0.0000 0.0000 0.0000

9 0.0140 0.0333 0.0011 0.0001 0.0000 0.0001

Average 0.0139 0.0337 0.0009 0.0001 0.0000 0.0001

EXAMPLE: LC Alloy 2

For this example, 3,340 kg of 97.5 percent pure molten aluminum metal was used, with 2 ingots (36 kg) of 6 percent zirconium master alloy added to the molten metal through a door on the furnace. In addition, 3.5 kg of boron was added to the metal. Tables 5 and 6 below show the resulting chemical composition of these samples again, in both molten alloy and cast rod form. The LC alloy 2 contained an average of about 0.0321 weight percent zirconium, with 0.0598 weight percent silicon, and 0.1205 weight percent iron in melt form, and about 0.0298 weight percent zirconium, with 0.0623 weight percent silicon, and 0.1180 weight percent iron in rod form.

TABLE 5

LC alloy 2 CHEMICAL COMPOSITION (MATTER ALLOY)

Weight Percent

Sample Si Fe Cu Mn Mg Cr Ni

A 0.0600 0.1240 0.0011 0.0044 0.0002 0.0003 0.0042

B 0.0600 0.1200 0.0011 0.0043 0.0002 0.0003 0.0041

C 0.0590 0.1190 0.0011 0.0043 0.0002 0.0003 0.0041

D 0.0600 0.1190 0.0011 0.0042 0.0002 0.0003 0.0040

Average 0.0598 0.1205 0.0011 0.0043 0.0002 0.0003 0.0041

Sample Zn Ti V Pb Sn B Be

A 0.0141 0.0000 0.0000 0.0021 0.0003 0.0015 0.0000

B 0.0143 0.0000 0.0000 0.0021 0.0006 0.0011 0.0000

C 0.0145 0.0000 0.0000 0.0020 0.0006 0.0012 0.0000

D 0.0135 0.0003 0.0000 0.0019 0.0000 0.0011 0.0000

Average 0.0141 0.0001 0.0000 0.0020 0.0004 0.0012 0.0000

Sample Ga Zr Cd Na Ca Li

A 0.0143 0.0318 0.0012 0.0001 0.0000 0.0000

B 0.0144 0.0322 0.0012 0.0001 0.0000 0.0000

C 0.0142 0.0322 0.0012 0.0001 0.0000 0.0000

D 0.0145 0.0321 0.0006 0.0000 0.0000 0.0000

Average 0.0144 0.0321 0.0011 0.0001 0.0000 0.0000

4^ *> UJ t lO

U» o O o u»>

show the chemical composition of these samples. The LC alloy 3 contained an average of about 0.0539 weight percent zirconium, with 0.0523 weight percent silicon, and 0.0895 weight percent iron in melt form, and about 0.0513 weight percent zirconium, with 0.0543 weight percent silicon, and 0.0905 weight percent iron in rod form.

TABLE 7

LC3 FINAL CHEMICAL COMPOSITION (MATTER ALLOY)

Weight Percent

Sample Si Fe Cu Mn Mg Cr Ni

A 0.0520 0.0910 0.0012 0.0037 0.0004 0.0003 0.0054

B 0.0520 0.0880 0.0012 0.0037 0.0004 0.0003 0.0054

C 0.0520 0.0890 0.0013 0.0037 0.0004 0.0003 0.0053

D 0.0530 0.0900 0.0013 0.0037 0.0004 0.0003 0.0054

Average 0.0523 0.0895 0.0013 0.0037 0.0004 0.0003 0.0054

Sample Zn Ti V Pb Sn B Be

A 0.0183 0.0010 0.0000 0.0018 0.0006 0.0015 0.0000

B 0.0185 0.0009 0.0014 0.0017 0.0006 0.0016 0.0000

C 0.0183 0.0000 0.0000 0.0018 0.0011 0.0010 0.0000

D 0.0185 0.0009 0.0000 0.0020 0.0012 0.0010 0.0000

Average 0.0184 0.0007 0.0004 0.0018 0.0009 0.0013 0.0000

Sample Ga Zr Cd Na Ca Li

A 0.0128 0.0554 0.0006 0.0001 0.0000 0.0000

B 0.0128 0.0540 0.0012 0.0000 0.0000 0.0000

C 0.0130 0.0533 0.0006 0.0001 0.0000 0.0000

D 0.0131 0.0530 0.0012 0.0001 0.0000 0.0000

Average 0.0129 0.0539 0.0009 0.0001 0.0000 0.0000

4^ ^ UJ J to to Oh O Ol o on o on on

EXAMPLE: LC Alloy 4

To further increase the resistance to the effects of stress relieving/annealing at temperatures around 200 degrees C, the LC alloy 4 includes an increase of zirconium to above 0.06 weight percent. In addition, "misch metal" was added to maintain acceptable rod conductivity. Furthermore, the cerium in the misch metal assists in maintaining the zirconium in a phase which, thus, minimizes the detrimental effect it has on conductivity. About 0.025 weight percent cerium was added to the melt. Specifically, for this example, 6,189 kg of 97.5 percent pure molten aluminum metal was used, with 7.5 ingots (54.5 kg) of 6 percent zirconium master alloy added to the molten metal through a metal charging spout. In addition, 3.2 kg of misch metal was added. Tables 9 and 10 below show the chemical composition of these samples. The LC alloy 4 contained an average of about 0.0662 weight percent zirconium, with 0.0460 weight percent silicon, and 0.0888 weight percent iron in melt form, and about 0.0636 weight percent zirconium, with 0.0465 weight percent silicon, and 0.0863 weight percent iron in rod form.

TABLE 9

LC4 CHEMICAL COMPOSITION (MATTER ALLOY)

Weight Percent

Sample Si Fe Cu Mn Mg Cr Ni

A 0.0460 0.0890 0.0001 0.0036 0.0008 0.0002 0.0061

B 0.0460 0.0870 0.0001 0.0036 0.0008 0.0003 0.0060

C 0.0460 0.0880 0.0002 0.0036 0.0008 0.0002 0.0060

D 0.0460 0.0910 0.0001 0.0036 0.0008 0.0003 0.0061

Average 0.0460 0.0888 0.0001 0.0036 0.0008 0.0003 0.0061

Sample Zn Ti V Pb Sn B Be

A 0.0201 0.0013 0.0000 0.0019 0.0007 0.0022 0.0000

B 0.0200 0.0010 0.0000 0.0020 0.0007 0.0013 0.0000

C 0.0201 0.0011 0.0000 0.0020 0.0006 0.0013 0.0000

D 0.0202 0.0015 0.0000 0.0021 0.0008 0.0018 0.0000

Average 0.0201 0.0012 0.0000 0.002 0.0007 0.0017 0.0000

Sample Ga Zr Cd Na Ca Li

A 0.0116 0.0662 0.0000 0.0002 0.0001 0.0000

B 0.0117 0.0660 0.0000 0.0001 0.0000 0.0000

C 0.0117 0.0662 0.0000 0.0001 0.0000 0.0000

D 0.0118 0.0665 0.0000 0.0001 0.0000 0.0000

Average 0.0117 0.0662 0.0000 0.0001 0.0000 0.0000

EXAMPLE: LC Alloy 5

The LC alloy 5 followed similar process parameters of that of LC alloy 4. Control of the chemical analysis was maintained within commercial standards for aluminum rod production of electrical conductors. For this example, 6,696 kg of 97.5 percent pure molten aluminum metal was used, with 3.33 ingots (48.5 kg) of 6 percent zirconium master alloy added to the molten metal through a metal charging spout. In similar fashion to the LC alloy 4, 3.31 kg of misch metal was added to the molten alloy of LC alloy 5. Tables 11 and 12 below show the chemical composition of samples A through D and rods from coils 1 through 10. The LC alloy 5 contained an average of about 0.0592 weight percent zirconium, with 0.0453 weight percent silicon, and 0.0750 weight percent iron in melt form, and about 0.0592 weight percent zirconium, with 0.0453 weight percent silicon, and 0.0750 weight percent iron in rod form.

TABLE 11

CHEMICAL COMPOSITION (MATTER ALLOY)

Weight Percent

Sample Si Fe Cu Mn Mg Cr Ni

LC I 0.0443 0.0851 0.0015 0.0040 0.0002 0.0000 0.0042

LC 2 0.0623 0.1180 0.0011 0.0042 0.0001 0.0003 0.0039

LC 3 0.0543 0.0905 0.0013 0.0037 0.0004 0.0006 0.0048

LC 4 0.0465 0.0863 0.0001 0.0036 0.0006 0.0003 0.0058

LC 5 0.0453 0.0750 0.0000 0.0037 0.0005 0.0004 0.0058

Sample Zn Ti V Pb Sn B Be

LC I 0.0158 0.0010 0.0000 0.0021 0.0005 0.0007 0.0000

LC 2 0.0139 0.0002 0.0000 0.0018 0.0005 0.0006 0.0000

LC 3 0.0165 0.0003 0.0000 0.0018 0.0008 0.0004 0.0000

LC 4 0.0188 0.0007 0.0000 0.0018 0.0013 0.0003 0.0000

LC 5 0.0195 0.0008 0.0000 0.0022 0.0014 0.0004 0.0000

Sample Ga Zr Cd Na Ca Li

LC I 0.0139 0.0337 0.0009 0.0001 0.0000 0.0001

LC 2 0.0144 0.0298 0.0018 0.0000 0.0000 0.0000

LC 3 0.0130 0.0513 0.0009 0.0001 0.0000 0.0001

LC 4 0.0116 0.0636 0.0000 0.0001 0.0000 0.0000

LC 5 0.0146 0.0592 0.0000 0.0001 0.0000 0.0001 TABLE 12

LC5 CHEMICAL COMPOSITION (CAST ROD)

Weight Percent

Coil Number Si Fe Cu Mn Mg Cr Ni

1 0.0460 0.0770 0.0001 0.0037 0.0005 0.0004 0.0058

2 0.0450 0.0740 0.0000 0.0037 0.0005 0.0004 0.0058

3 0.0460 0.0750 0.0000 0.0037 0.0005 0.0004 0.0058

4 0.0440 0.0740 0.0000 0.0037 0.0005 0.0004 0.0057

5 0.0460 0.0780 0.0000 0.0037 0.0005 0.0004 0.0059

6 0.0460 0.0770 0.0000 0.0037 0.0005 0.0004 0.0059

7 0.0440 0.0750 0.0000 0.0037 0.0005 0.0004 0.0058

8 0.0450 0.0780 0.0001 0.0038 0.0006 0.0004 0.0059

9 0.0440 0.0740 0.0000 0.0037 0.0005 0.0003 0.0057

10 0.0470 0.0770 0.0000 0.0037 0.0005 0.0004 0.0058

Average 0.0453 0.0750 0.0000 0.0037 0.0005 0.0004 0.0058

Coil Number Zn Ti V Pb Sn B Be

1 0.0195 0.0008 0.0000 0.0022 0.0013 0.0003 0.0000

2 0.0195 0.0008 0.0000 0.0022 0.0013 0.0005 0.0000

3 0.0197 0.0008 0.0000 0.0023 0.0015 0.0003 0.0000

4 0.0193 0.0007 0.0000 0.0021 0.0014 0.0003 0.0000

5 0.0197 0.0008 0.0000 0.0023 0.0015 0.0004 0.0000

6 0.0198 0.0008 0.0000 0.0023 0.0014 0.0005 0.0000

7 0.0197 0.0008 0.0000 0.0022 0.0013 0.0004 0.0000

8 0.0199 0.0008 0.0000 0.0023 0.0014 0.0004 0.0000

9 0.0193 0.0007 0.0000 0.0020 0.0012 0.0004 0.0000

10 0.0195 0.0007 0.0000 0.0023 0.0014 0.0003 0.0000

Average 0.0195 0.0008 0.0000 0.0022 0.0014 0.0004 0.0000

Coil Number Ga Zr Cd Na Ca Li

1 0.0147 0.0599 0.0000 0.0001 0.0000 0.0001

2 0.0146 0.0603 0.0000 0.0001 0.0000 0.0001

3 0.0146 0.0570 0.0000 0.0001 0.0000 0.0001

4 0.0144 0.0597 0.0000 0.0001 0.0000 0.0000

5 0.0147 0.0565 0.0000 0.0001 0.0000 0.0001

6 0.0147 0.0599 0.0000 0.0001 0.0000 0.0001

7 0.0143 0.0599 0.0000 0.0001 0.0000 0.0000

8 0.0145 0.0595 0.0000 0.0001 0.0000 0.0001

9 0.0141 0.0602 0.0000 0.0001 0.0000 0.0000

10 0.0148 0.0593 0.0000 0.0001 0.0000 0.0001

Average 0.0146 0.0592 0.0000 0.0001 0.0000 0.0001

ROD TESTING

As a preliminary suitability test, the LC alloy rods were tested against an EC rod. As a control, a rod sample was taken from one 2-ton EC coil. All LC alloy testing was performed and compared against this control rod. A sample rod was also taken from each of the resulting 400 kg LC alloy coils 1 through 5. These tests confirm consistency in the rod's mechanical and electrical properties, as well as its chemical composition throughout production.

The following testing results were determined by testing between 8 and 11 sample rods for each LC alloy 1 through 5 and compared to the EC control rod. All mechanical and electrical resistance tests were performed under the following ASTM specifications: ASTM-B 193, 1999, Test Method for Resistivity of Electrical Conductor Materials; and ASTM - B 557, Test Method of Tension Testing Wrought and Cast Aluminum, 1999. As shown in Tables 13 through 16, these tests confirm that the LC alloy rods have similar strength and electrical conductivity.

TABLE 13

ROD TENSILE STRENGTH (kg/cm2 )

EC LC 1 LC 2

Coil Inside Outside Inside Outside Inside Outside Number

1 10.9 11.1 13.6 12.1 12.4 11.3

2 12.1 12.7 11.3 11.8 3 12.7 13.0 11.8 11.4 4 13.0 13.0 11.4 13.4 5 13.0 11.6 13.4 11.2 6 11.6 12.1 11.2 11.4 7 12.1 11.9 11.4 11.4 8 11.9 11.1 11.4 11.5 9 11.1 11.2 10 11 Average 10.9 12.2 11.7

TABLE 16

ROD CONDUCTIVITY (PERCENT IACS)

Coil Number EC LC I LC 2 LC 3 LC 4 LC 5

1 62.5 60.6 60.1 60.2 60.0 60.1

2 60.6 60.2 60.1 60.0 60.1

3 60.8 60.2 60.3 60.0 60.4

4 60.6 60.2 60.1 60.1 60.2

5 60.7 60.2 60.4 60.0 60.1

6 61.0 60.4 60.1 60.0 60.1

7 60.8 60.3 60.4 60.0 60.0

8 61.0 60.2 60.1 60.3 60.2

9 60.8 60.3 60.1 60.1

10 60.2 60.0 60.0

11 60.1

Average 60.8 60.2 60.2 60.1 60.1

WIRE TESTING

In preparation for wire testing, each LC alloy rod was drawn into wire, producing 19 bobbins. During the wire drawing process, 5 of the 19 bobbins of wire were tested. The wire count was chosen as it was because they will eventually be stranded into a 336.4 MCM, 19 strand cable, for further testing. The EC rod was also drawn into a wire to again serve as a control. A total of 19 wires were drawn from EC rod so that a cable can be stranded therefrom, similar to the LC wires. The wires were aged at various temperatures for various lengths of time. Specifically, the wires aged at temperatures between 150 degrees C to 210 degrees C for either 150, 200 or 500 hours. (See Tables 18 through 27.) After aging and cooling, the wires were subjected to the following ASTM and Aluminum Association tests: B 263-94, Determination of Cross-Sectional Area of Stranded Conductors, B 830-97, Uniform Test Methods & Frequency, B 193, Test Method for Resistivity of Electrical Conductors, B 231-95, Concentric-Lay-Stranded Aluminum 1350 Conductors, 1999, and A Method of Stress-Strain Testing of Aluminum Conductors and ACSR and A Test Method for Determining the Long Time Tensile Creep of Aluminum Conductors in Overhead Lines.

Table 17 shows the characteristics of the LC alloy 1 through 5 wires in comparison to the EC control wire prior to stranding. Table 17 represents the average of 19 wires "cable total," wherein 3 samples of each wire were tested 3 times and an average value taken. This table demonstrates that the performance of all the

LC alloy wires are generally consistent with the EC wire in both strength and conductivity. Though the EC wire shows a slightly higher conductivity, the LC wires are still within an acceptable tolerance.

TABLE 17 AVERAGE RESULTS FOR 19 WIRE BEFORE STRANDING

Characteristics ^A^°^y LC I LC 2 LC 3 LC 4 LC 5

Diameter ( mm ) 3.39 3.38 3.39 3.39 3.39 3.39

Tension Strength ( Mpa ) 194 188 191 193 195 187

Tensile strength (kg/mm²) 19.78 19.17 19.48 19.68 19.88 19.07

Elongation ( % ) 5.0 5.5 5.5 5.5 5.5 5.5

Conductivity ( % IACS ) 62.0 60.3 59.7 60 59.4 59.5

Each wire was then placed in ovens, prior to stranding and stress relieving/annealing, at temperatures ranging from 150 to 200 degrees C for 100 hours. Again, all of the tests were conducted using an EC wire as the control. LC alloys 1 through 5 all demonstrated that they could maintain higher tension strength compared to EC even after being aged at 200 degrees C for extended periods of time. During the creep tests, LC alloy 4, in particular, demonstrated less "creep" than that of the EC wire under the same conditions. Tables 18 and 19 show the results, as well as the conductivity, for the five LC alloy wire and EC wire samples. It is noted that Table 1 shows a summary of these results as well.

TABLE 18

AVERAGE RESULTS FOR 5 SAMPLES OF WIRE AFTER AGED 100HR @ 150 DEGREES C

Characteristics ^AJϊ^y LC I LC 2 LC 3 LC 4 LC 5

E

Diameter ( mm ) 3.39 3.39 3.39 3.39 3.39 3.39

Tension Strength ( Mpa ) 193 191 186 185 195 185

Tension Strength 19.48 NA NA 18.67 19.68 18.67

(kg/mm²)

Elongation ( % ) 5.5 6.0 5.5 5.5 5.5 5.5

Conductivity ( % IACS ) 62 60.9 60.7 59.8 59.4 59.7 TABLE 19

AVERAGE RESULTS FOR 5 SAMPLES OF WIRE AFTER AGED 100HR @ 200 DEGREES C

Characteristics ^Λ^°^y LC I LC 2 LC 3 LC 4 LC 5

EC Diameter ( mm ) 3.38 - -- 3.40 3.40 3.40

Tension Strength ( Mpa ) 143 - -- 166 174 164

Tension Strength (kg/mm²) 14.43 -- - 16.76 17.56 16.55

Elongation ( % ) 4.5 - - 5.0 5.0 5.5

Conductivity ( % IACS ) 62.4 - - 60.4 59.9 60.6

Wire samples were also aged (stress relieving/annealing) at temperatures from 140 to 210 degrees C for 500 hours in ten degree increments, cooled, and then tested. All of the tests were conducted, again, using an EC cable as the control. The LC alloy cables 1 through 5 all demonstrated that they could appreciably maintain their tension strength even after being aged for 500 hours.

Tables 20 through 27 show the results of the relieving/annealing tests for wires aged at temperatures between 140 and 210 degrees C. The chart of Fig. 1 shows the tension strength results between EC and LC wires, not only from the tables below, but also from wires aged at temperatures between 80 and 130 degrees C, as well for 500 hours. The chart in Fig. 1 shows that the LC alloy wires consistently maintain a higher tension strength than the EC wire through the annealing temperature range.

TABLE 20

AVERAGE RESULTS FOR 5 SAMPLES OF WIRE AFTER AGED 500HR @ 140

DEGREES C

Characteristics ^A^^y LC I LC 2 LC 3 LC 4 LC 5 EC

Diameter ( mm ) 3.38 3.38 3.39 3.39 3.38 3.38

Tension Strength ( Mpa ) 159 168 166 163 165 175

Tension Strength ( kg/mm²) 16.05 16.96 16.76 16.45 16.66 17.66

Elongation ( % ) 5.0 5.5 5.5 5.0 5.0 5.0

Conductivity ( % IACS ) 62.8 62.8 62.7 60.5 60 60.1 TABLE 21

AVERAGE RESULTS FOR 5 SAMPLES OF WIRE AFTER AGED 500HR @ 150

DEGREES

Alloy _{τ p 1}

Characteristics LC 2 LC 3 LC 4 LC 5 EC ^{LC 1}

Diameter ( m ) 3.39 3.38 3.38 3.39 3.39 3.39 Tension Strength ( Mpa ) 155 161 167 168 171 165 Tension Strength ( kg/mm²) 15.65 16.25 16.86 16.96 17.26 16.66 Elongation ( % ) 5.0 5.5 5.5 5.5 5.5 5.5 Conductivity ( % IACS ) 62.3 61.1 60.6 60.5 60.1 60.1

TABLE 22

AVERAGE RESULTS FOR 5 SAMPLES OF WIRE AFTER AGED 500HR @ 160

DEGREES C

Characteristics ^A^^y LC I LC 2 LC 3 LC 4 LC 5 EC

Diameter ( mm ) 3.40 3.39 3.39 3.39 3.39 3.39 Tension Strength ( Mpa ) 160 161 166 168 165 168 Tension Strength ( kg/mm²) 16.15 16.25 16.76 16.96 16.66 16.96 Elongation ( % ) 5.5 5.5 5.5 5.5 5.5 5.5 Conductivity ( % IACS ) 62.5 61.1 60.9 60.3 60.1 60.3

TABLE 23

AVERAGE RESULTS FOR 5 SAMPLES OF WIRE AFTER AGED 500HR @ 170

DEGREES C

Characteristics ^ LC . LC 2 LC 3 LC 4 LC 5

Diameter ( mm ) 3.39 3.37 3.39 3.38 3.38 3.39 Tension Strength ( Mpa ) 152 161 164 165 173 159 Tension Strength ( kg/mm²) 15.34 16.25 16.55 16.66 17.46 16.05 Elongation ( % ) 5.5 5.5 5.5 5.5 5.5 5.0 Conductivity ( % IACS ) 62.3 61.3 61.1 60.5 60.3 60.1

TABLE 24

AVERAGE RESULTS FOR 5 SAMPLES OF WIRE AFTER AGED 500HR @ 180

DEGREES C

Alloy

Characteristics LC 1 LC 2 LC 3 LC 4 LC 5 EC

Diameter ( mm ) 3.39 3.38 3.38 3.39 3.38 3.38

Tension Strength ( Mpa ) 143 145 144 152 156 148

Tension Strength ( 14.43 14.64 14.54 15.34 15.75 14.94 kg/mm²)

Elongation ( % ) 5.0 5.0 5.0 5.0 5.0 5.0

Conductivity ( % IACS ) 62.6 60.9 61.2 60.6 60.2 60.3 TABLE 25

AVERAGE RESULTS FOR 5 SAMPLES OF WIRE AFTER AGED 500HR @ 190

DEGREES C

Characteristics ^A^^y LC I LC 2 LC 3 LC 4 LC 5

UC

Diameter ( mm ) 3.38 3.38 3.39 3.38 3.39 3.37

Tension Strength ( Mpa ) 156 156 159 163 162 159

Tension Strength (kg/mm²) 15.75 15.75 16.05 16.45 16.35 16.05

Elongation ( % ) 5.5 5.0 5.5 5.5 5.5 5.5

Conductivity ( % IACS ) 62.8 60.9 61.0 62.1 61.7 61.4

TABLE 26

AVERAGE RESULTS FOR 5 SAMPLES OF WIRE AFTER AGED 500HR @ 200 DEGREES C

Characteristics Alloy EC LC I LC 2 LC 3 LC 4 LC 5

Diameter ( mm ) 3.39 3.38 3.38 3.39 3.38 3.38

Tension Strength ( Mpa ) 144 156 155 157 161 161

Tension Strength ( kg/mm²) 14.54 15.75 15.65 15.85 16.25 16.25

Elongation ( % ) 5.5 5.0 5.0 6.0 6.0 5.5

Conductivity ( % IACS ) 62.5 61.3 60.2 60.7 60.1 60.2

TABLE 27

AVERAGE RESULTS FOR 5 SAMPLES OF WTRE AFTER AGED 500HR @ 210

DEGREES C

Alloy LC LC LC

Characteristics LC 3 LC 5 EC 1 2 4

Diameter ( mm ) 3.39 3.37 3.39 3.39 3.39 3.38

Tension Strength ( Mpa ) 162 151 151 173 162 153

Tension Strength ( kg/mm²) 16.35 15.24 15.24 17.46 16.35 15.44

Elongation ( % ) 5.0 5.5 5.5 6.0 6.0 5.5

Conductivity ( % IACS ) 62.6 61.2 61 60.8 60.2 60.1

CABLE TESTING

After drawing rods of each composition into wires, they are stranded into a 336.4 MCM, 19 strand cable. Such cables had an illustrative length between about 12 to 15 meters for cable breaking load testing, and were aged at 150 degrees C and 200 degrees C for 500 hours. Once the cable samples were removed from the evaluated temperature and cooled to ambient temperature, the test procedure was initiated. Cables were tested pursuant to the following ASTM and Aluminum Association tests: B 263-94, Determination of Cross-Sectional Area of Stranded Conductors, B 830-97, Uniform Test Methods & Frequency, B 193, Test Method for Resistivity of Electrical Conductors, B 231-95, Concentric-Lay-Stranded Aluminum 1350 Conductors, 1999, and A Method of Stress-Strain Testing of Aluminum Conductors and ACSR and A Test Method for Determining the Long Time Tensile Creep of Aluminum Conductors in Overhead Lines. Table 28, like Table 17, shows the characteristics of the LC alloy 1 through 5 cables in comparison to the EC control cable before aging. This tables demonstrates that the performance of all the LC alloy cables were generally consistent with the EC cable in both strength and conductivity. Though the EC cable still shows a slightly higher conductivity, the LC cables are still within an acceptable tolerance.

TABLE 28

AVERAGE RESULTS FOR 19 WIRE AFTER STRANDING

Characteristics ^A^°^Y LC 1 LC 2 LC 3 LC 4 LC 5

Diameter ( mm ) 3.40 3.39 3.38 3.39 3.39 3.38

Tension Strength ( Mpa ) 194 191 192 193 196 186

Tension Strength (kg/mm²) 19.58 19.28 19.38 19.48 19.78 18.78

Elongation ( % ) 5.0 5.0 5.5 5.5 5.5 5.5

Conductivity ( % IACS ) 62 60.2 59.9 60.1 59.4 60

The charts shown in Figs. 2 and 3 demonstrate an increased strength in the LC cables relative to the EC cable. Specifically, Fig. 2 shows the comparison of the 336.4 MCM, 19 strand cable breaking strength of each alloy prior to and after being subjected to elevated temperatures for 500 hours. In almost all instances, the LC cables exhibited unexpectedly superior tension strength at the elevated temperatures.

Although the foregoing embodiments have been described, one skilled in the art can easily ascertain the essential characteristics of the device, and various changes and modifications may be made to adapt the various uses and characteristics without departing from the spirit and scope of this application, as described by the claims which follow.

Claims

What is claimed is:

1. A low creep electrical conducting aluminum cable wire alloy comprising: about 0.07 to about 0.12 weight percent iron; about 0.04 to about 0.07 weight percent silicon; about 0.03 to about 0.08 weight percent zirconium; and a balance weight percent of aluminum.

2. The aluminum cable wire alloy of Claim 1, further comprising about 0.02 weight percent of cerium.

3. The aluminum cable wire alloy of Claim 1, further comprising about 0.03 to about 0.06 weight percent zirconium.

4. The aluminum cable wire alloy of Claim 1, further comprising about 0.04 to about 0.05 weight percent misch metal.

5. The aluminum cable wire alloy of Claim 4, wherein the misch metal comprises about 50 weight percent cerium, about 25 weight percent lanthanum, about 18 percent neodymium and about 8 percent praseodymium.

6. The aluminum cable wire alloy of Claim 1, further comprising about 0.005 weight percent boron.

7. A low creep cable wire alloy comprising an al minum alloy, the aluminum alloy comprising about 99.8 weight percent pure aluminum, and having an effective amount of iron, silicon and zirconium to produce a tensile strength of greater than about 18 kg/mm² and a conductivity of about 60 percent IACS in an environment of 150 degrees C for about 100 hours, wherein the effective amount of iron is about 0.12 weight percent and below, the effective amount of silicon is about 0.07 weight percent and below, and the effective amount of zirconium is about 0.08 weight percent and below.

8. The aluminum cable wire alloy of Claim 7, further comprising from about 0.0015 to about 0.005 weight percent boron.

9. A low creep cable wire alloy comprising an aluminum conductor having an effective amount of iron, silicon, zirconium and cerium to produce a tensile strength of greater than about 16 kg/mm² and a conductivity of about 59.0 to 60.0 percent IACS after being subject to an environment of 200 degrees C for 100 to 500 hours, wherein the effective amount of iron is about 0.12 weight percent and below, the effective amount of silicon is about 0.07 weight percent and below, the effective amount of zirconium is about 0.08 weight percent and below, and the effective amount of cerium is about 0.025 weight percent.

10. The aluminum cable wire alloy of Claim 9, wherein the aluminum conductor is at least about 99.8 weight percent pure aluminum prior to alloying.

11. The aluminum cable wire alloy of Claim 9, further comprising from about 0.0015 to about 0.002 weight percent boron.

12. A low creep electrical conducting aluminum alloy comprising: about 0.025 to about 0.075 weight percent zirconium; about 0.015 to about 0.035 weight percent cerium; less than about 0.14 weight percent iron; less than about 0.08 weight percent silicon; less than about 0.004 weight percent trace elements; less than about 0.003 weight percent boron; and a balance weight percent of aluminum.

13. The aluminum cable wire alloy of Claim 12, wherein the aluminum conductor is at least about 99.7 weight percent pure aluminum.

14. The aluminum cable wire alloy of Claim 12, wherein misch metal comprises about 0.015 to about 0.035 weight percent cerium.

15. The aluminum cable wire alloy of Claim 12, wherein the trace elements are titanium, vanadium, and chromium.

16. A low creep electrical conducting aluminum alloy comprising: about 0.030 to about 0.070 weight percent zirconium; about 0.018 to about 0.030 weight percent cerium; less than about 0.10 weight percent iron; less than about 0.06 weight percent silicon; less than about 0.003 weight percent trace elements; less than about 0.002 weight percent boron; and a balance weight percent of aluminum.

17. The aluminum cable wire alloy of Claim 16, wherein the trace elements are titanium, vanadium, and chromium.

18. A low creep electrical conducting aluminum alloy comprising: about 0.025 to about 0.075 weight percent zirconium; less than about 0.14 weight percent iron; less than about 0.08 weight percent silicon; less than about 0.004 weight percent trace elements; less than about 0.003 weight percent boron; and a balance weight percent of aluminum.

19. The aluminum cable wire alloy of Claim 18, wherein the trace elements are titanium, vanadium, and chromium.