FI59423B - ELEKTRISK LEDARE AV ALUMINIUMLEGERING SAMT FOERFARANDE FOER FRAMSTAELLNING AV DENNA - Google Patents

Description

M ADVERTISING PUBLICATION r ~. _ [BJ (1) UTLÄ6GNINGSSKRIFT 5 942 3 C (45) Patent -nySiin · 'tiy 10 00 10iU Patent -nodlelat ^ ^ (51) Kv.ik.V.ci.3 C 22 C 21/00 // H 01 B 1/02 FINLAND — FINLAND (21) Patunttlhukumut - PatununaSkning 1593/72 (22) Hakumlaptlvl - AnatMinlngarfag 06.06.72 '' (23) AlkupMvt — Glltlghatsdag 06.06.72 (11) Interpreters slipped - Bllvlt offuntllg 08.12.12 08 . , ^ (44) Date of external appearance of NihtivUcilpunon | -, Λ

Patent and registration authorities Ansekan utisgd och utUkrtitun pubiicerad 30.01.8l (32) (33) (31) utuoikuu * —Buglrd prlorltrt 07.06.71

USA (US) I5O72I

(71) Southvire Company, 126 Fertilla Street, Carrollton, Georgia 30117, USA (72) Roger John Schoerner, Carrollton, Georgia, Enrique Calixto Chia, Carrollton, Georgia, USA (7I) Leitzinger Oy (5I) The present invention relates to an aluminum-based alloy which is particularly suitable for the production of high-strength and light electrical conductors, including wires, rods and other such workpieces. , as a rod, cable, assembly rod, pipe connector, terminal, manifold plug or electrical switching device for conducting electricity.

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Aluminum-based alloys are finding more and more use in modern commerce due to their light weight and low price. One area where aluminum alloys have found increasing use is the replacement of copper in the manufacture of electrically conductive wire. Conventional electrically conductive aluminum alloy wires (referred to as EC) contain a substantial amount of pure aluminum and trace amounts of impurities such as silicon, vanadium, iron, copper, manganese, magnesium, zinc, boron and titanium.

Although aluminum alloys are desirable in terms of weight and price, they have not achieved nearly full acceptance in the marketing of electrical conductors. One of the main reasons for the lack of full acceptance is the range of physical properties that can be obtained with conventional EC aluminum alloy conductors.

If physical properties such as thermal stability, tensile strength, percent elongation, forging, and yield strength could be significantly improved without substantially reducing the electrical conductivity of the finished product, a well-desired improvement would be achieved. However, it is known that the addition of alloying agents, as in other aluminum alloys, reduces conductivity while improving physical properties. Thus, only those additions of elements that significantly improve physical properties without compromising conductivity will yield an acceptable and useful product.

It is therefore an object of the present invention to provide a novel aluminum-alloy electrical conductor which combines better physical properties with acceptable electrical conductivity. These and other objects, features and advantages of the present invention will become apparent upon consideration of the following detailed description of an embodiment of the invention.

According to the invention, this aluminum-based alloy is prepared by mixing nickel, iron and optionally other alloying elements with aluminum in a furnace to obtain a melt with the required percentages of elements. It has been found that suitable results are obtained when nickel is present in an amount of about 0.20 to about 1.60% by weight. Better results are obtained when nickel is present in an amount of about 0.50 to about 1.00% by weight, and particularly good and recommended results are obtained when nickel is present in an amount of about 0.60 to about 0.80%.

Suitable results are obtained when iron is present in an amount of about 0.30 to about 1.30% by weight. Better results are obtained when iron is present in an amount of about 0.40 to about 0.80% by weight, and particularly good and recommended results are obtained when iron is present. about 0.45 to about 0.65 weight percent.

The aluminum content of the present alloy can range from about 97.00% to about 99.50 weight percent, and the best results are obtained when the aluminum content ranges from about 97.80 to about 99.20 weight percent. Since the percentages of maximum and minimum aluminum content do not correspond to the maximum and minimum amounts of alloying elements, it should be obvious that suitable results will not be obtained if maximum percentages are used for all alloying elements. If commercial aluminum is used in the manufacture of the present melt, it is recommended that the aluminum, before being added to the melt in the furnace, does not contain more than a total of 0.10% of trace impurities.

Alternatively, the present alloy may contain another alloy-forming element or a group of alloy-forming elements. The total concentration of the elements forming the optional alloys can be up to about 2.00% by weight; about 0.10 to about 1.50 weight percent is recommended. Particularly good and recommended results are obtained when a total of about 0.10 to about 1.00% by weight of other alloying elements are used.

Other alloying elements include:

Other alloying elements

Magnesium Skandium Dysprosium

Cobalt Torium Terbium

Copper Tina Erbium

Silicon Molybdenum Neodymium

Zircon Zinc Indium

Serium Wolframi Boori

Niobium Chromium Thallium 59423

Hafnium Bismuth Rubidium

Lanthanum Antimony Titanium

Tantalum Vanadium Carbon

Cesium Rhenium

yttrium

For best results, use the following percentages by weight of the other alloying elements:

Recommended other alloying elements

Magnesium 0.001 - 1.00%

Cobalt 0.001 - 1.00%

Copper 0.05 - 1.00%

Si 0.05 - 1.00%

Zircons 0.01 - 1.00%

Niobium 0.01 - 2.00%

Tantalum 0.01 - 2.00%

Yttrium 0.01 - 1.00%

Scandium 0.01 - 1.00%

Thorium 0.01 - 1.00%

Rare earth metals 0.01 - 2.00%

Carbon 0.01 - 1.00%

Particularly good and recommended results are obtained when cobalt or magnesium is used as another alloying element. Suitable results are obtained with magnesium or cobalt in a percentage range of about 0.001 to about 1.00 weight percent, and better results are obtained when using about 0.025 to about 0.50 weight percent. Particularly good and recommended results are obtained when magnesium or cobalt is used in an amount of about 0.03 to about 0.10% by weight.

Rare earth metals may be present either alone in the declared percentage range or as a subgroup or overall group, with the total percentage of the group being in the previously declared percentage range.

It will be appreciated that other alloying elements may be present either alone or as a group of two or more elements. It is to be understood, however, that if two or more other alloying elements of s 59423 are used, the total concentration of other alloying elements should not exceed about 2.00% by weight.

After production of the melt, the aluminum alloy is cast into a continuously continuous rod as recommended by a continuous casting machine and then, substantially immediately thereafter, scraped in a rolling mill to obtain a continuous aluminum alloy rod.

An example of a continuous casting and rolling operation capable of producing a continuous bar as defined in this study is given in the following paragraphs. It will be appreciated that other manufacturing methods may be used to obtain suitable results, but that the recommended results will be obtained by continuous processing. Such other methods include conventional extrusion and hydrostatic extrusion to provide a rod or wire directly, sintering of aluminum alloy powder to obtain a rod or wire directly, casting the rod or wire directly from a molten aluminum alloy, and drawing the conventional aluminum alloy after casting into castings.

Continuous casting and rolling

A continuous casting machine acts as a means of solidifying molten aluminum alloy metal to obtain a casting rod which is transported substantially in the state in which it solidified from a continuous casting machine to a rolling mill acting as a means of hot-forming movement on the casting rod along a plurality of angled axes.

A continuous casting machine is a conventional type of casting wheel having a casting wheel with casting grooves on its circumference which is partially closed by an endless belt worn by a casting wheel and an intermediate wheel. The casting wheel and the endless belt work together to form a mold at one end of which the molten metal is poured to solidify and at the other end of which the casting rod is substantially removed in the state in which it solidified.

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The rolling mill is of the conventional type having a plurality of pairs of roller chairs arranged to thermoforming the casting bar by means of a series of deformations. The continuous casting machine and the rolling mill are located relative to each other so that the casting bar enters the rolling mill substantially immediately after solidification and substantially in the state in which it solidified. In this state, the casting rod is at the thermoforming temperature in the temperature range for thermoforming the casting rod at the beginning of the thermoforming without heating between the casting machine and the rolling mill. In the event that it is desirable to precisely control the hot molding temperature of the ingot in the conventional range of thermoforming temperatures, the ingot temperature control devices may be positioned between the continuous casting machine and the rolling mill without departing from the inventive step disclosed herein.

Each pair of roller chairs includes several rollers that engage the casting rod. The rollers of each pair of roller chairs may be two or more arranged diametrically opposite each other or arranged at equally spaced points around the axis of movement of the casting bar through the rolling mill. The roll of each pair of rolling mills in a rolling mill is rotated at a predetermined speed by a power source such as one or more electric motors, and the casting wheel is rotated at a speed generally determined by its operating conditions. The rolling mill operates by thermoforming the casting rod into a rod having a substantially smaller cross-sectional area than the casting rod when it enters the rolling mill.

The circumferential surfaces of the rolls of adjacent pairs of roll chairs in the rolling mill change in configuration; i.e., the casting bar is gripped by rollers of successive pairs of roller chairs with different configurations on their surfaces, from different directions. This variable surface adhesion of the casting rod in the pairs of rolled chairs works by shaping or shaping the metal in the casting rod in such a way that it is machined in each pair of rolled chairs, and at the same time reduces and converts the cross-sectional area of the casting rod to rod-like.

Since each pair of roller chairs adheres to the casting bar, it is desirable that the casting bar be received in sufficient volume per unit time in the pair of rolling chairs so that the casting bar generally fills the space defined by the rollers of the pair of rollers. However, it is also desirable that the space defined by the rollers of each pair of roller chairs not be overfilled so that the casting rod is not forced into the openings between the rollers. Thus, it is desirable for the rod to be fed to each pair of roller chairs at a volume per unit time sufficient to fill, but not overfill, the space defined by the rollers of the roller chair pairs.

When the casting rod is received from a continuous casting machine, it usually has one larger flat surface corresponding to the surface of the endless belt and inwardly tapering side surfaces corresponding to the shape of the groove in the casting wheel. As the rollers of the pairs of rollers compress the casting bar, the shape of the casting bar changes so that it generally acquires in its cross-section a shape defined by the perimeters adjacent to the rollers of each pair of rollers.

Thus, it is understood that this apparatus produces an unlimited number of aluminum alloy casting bars of different lengths simultaneously by casting a molten aluminum alloy and thermoforming or rolling an aluminum casting bar. The continuous rod has an electrical conductivity of 57% according to the IAC standard and can be used to conduct electricity or it can be drawn into a wire with a smaller cross-sectional diameter.

To produce yarns of different thicknesses, the continuous rod produced by casting and rolling is reduced, the impermeable rod (i.e., rolled to f-degree) is cold drawn through a series of progressively tapered nozzles without passing in between, forming a continuous wire of the desired diameter. It has been found that omitting intermediate emissions is recommended during rod handling and improves the physical properties of the yarn. Treatment with intermediate emissions is acceptable when the requirements for the physical properties of the wire allow lower values. The electrical conductivity of the hardened wire is at least 57% IACS. If greater electrical conductivity or greater elongation is desired, the wire may be released or partially released after the desired wire size is obtained and cooled. The electrical conductivity of a fully released wire is at least 58% IACS. As a result of the tensile operation or the optional release, it has been found that the alloy wire has the properties previously defined in this application: better tensile and yield strength as well as better thermal stability, final percentage elongation and better forging and fatigue strength. The discharge may be continuous, such as in resistance discharge, induction emission, convection emission in continuous furnaces, or radiation emission in continuous furnaces, or, preferably, it may be batch-released in a batch furnace. For continuous release, temperatures of about 232 to about 649 ° C can be used with release times of about 5 minutes to about 1 / 10,000 minutes. In general, however, continuous discharge temperatures and times can be adjusted to meet the requirements of the overall treatment in question as long as the desired physical properties are achieved. The batch discharge uses a temperature of about 204 to about 399 ° C with residence times of about 30 minutes to about 24 hours. As mentioned for continuous emission, in batch emissions, times and temperatures can be varied to suit the overall process as long as the desired physical properties are obtained.

It has been found that the properties of the fully released soft wire with an thickness of 10 (American wire gauge) from the present alloy vary within the following limits:

Conductivity Tensile strength, kg / bn t-elongation yield strength, kg / cm 58% -63 +% 844 - 1688 12% -30% 562 - 1266

The invention will be more fully understood from the following examples:

Example No. 1

Various melts were prepared by adding the required amount of alloying elements to 1816 g of molten aluminum containing less than 0.10% of trace element impurities to give the percentage concentration of elements shown in the attached table; the rest is aluminum. Graphite crucibles are used, except in cases where the alloying elements are known carbide formers, in which case alumina crucibles are used. The melt is maintained long enough and at sufficient temperatures to allow complete dissolution of the alloying elements with the base aluminum. An argon atmosphere is used over the melt to prevent oxidation. Each melt is continuously cast on a continuous casting machine and immediately hot rolled through a rolling mill to a continuous bar of 9.53 mm. K are a pko (: - 'l -sutt as 5 were then drawn and released into a soft yarn (released) of S t-.mtia I3m.p £ vt \; Ί. ^ 10y.

Final obtained longinia] ..}.; - ϋο- ί ^ · '.k · 2,, 5333 ποιο, thickness No. 10 AWG.

5 94 23 The alloys used and the results of the tests performed on them are as follows:

table 1

M Ie LVL% IACS

.30 1.00 17 s 000 12.5 ϋυ, 49, 80, 70 18,300 25.0 59.73 1.00, 50 17,900 25.1 59.97 1.50, 40 17,800 21.8 59.52% at least two items. s final% ~ pitfmemä LVL = final bet '! ui> hi «% IACS = conductivity. 5 1 Ac: ',

Example No. 2

A second melt was prepared according to Example 1 so that the composition by weight was as follows: Nickel ~ 0.60%

Iron · 0.90 5

Magnesium ~ 0.15 '*>

Aluminum - the rest

The melt was treated as a soft hole, the thickness of the hip was No. 10. The physical properties of the yarn were as follows:

, O

Final tensile strength - 1280 kg / cm

Final pro s ent t ip i t e n e 25 ,? %

Conductivity - 59, .i.O% IACS

Example No. 3

A second 2oj ~ 'ham was prepared according to mark No. 1, so that the composition n0.00opr? · <Εonτteina was as follows: 10 59423

Nickel - 0.40%

Iron - 1.10%

Aluminum - The rest

The melt was processed into a soft yarn having a thickness of No. 10. The physical properties of the yarn were as follows: 2

Final tensile strength - 1223 kg / cm

Final percentage increase - 14.1%

Conductivity - 60.30% IACS

Example No. 4

A second alloy melt was prepared according to Example No. 1 so that the composition in weight percent was as follows:

Nickel - 1.60%

Iron - 0.30%

Aluminum - The rest

The melt was processed into a soft yarn having a thickness of No. 10. The physical properties of the yarn were as follows: 2

Final tensile strength - 1209 kg / cm

Final percentage increase - 27.5%

Conductivity - 59.1% IACS

Example No. 5

A second alloy melt was prepared according to Example No. 1 so that the composition in weight percent was as follows:

Nickel - 0.20%

Iron - 1.30%

Aluminum - The rest

The melt was processed into a soft yarn having a thickness of No. 10. The physical properties of the yarn were as follows: 2

Final tensile strength - 1230 kg / cm

Final percentage elongation - 13.5%

Conductivity - 61.05% IACS

11 59423

Example No. 6

A second alloy melt was prepared according to Example No. 1 so that the composition in weight percent was as follows:

Nickel - 0.80%

Iron - 0.45%

Cobalt - 0.10%

Aluminum - The rest

The melt was processed into a soft yarn having a thickness of No. 10. The physical properties of the yarn were as follows: 2

Final tensile strength - 1255 kg / cm

Final percentage increase - 23.6%

Conductivity - 59.8% IACS

By testing and analyzing an alloy containing 0.80% by weight of nickel, 0.30% by weight of iron and the remainder of aluminum, it has been found that the present aluminum-based alloy after cold working contains intermetallic compound precipitates. One of the identified compounds is nickel aluminate (NiAlg) and the other has been identified as iron aluminate (FeAlj). The intermetallic nickel compound has been found to be very stable and in particular it is stable at high temperatures. The nickel compound also has a low tendency to fuse together during the release of the products formed from the alloy and the compound is generally inconsistent with the aluminum matrix. The reinforcement mechanism of this alloy is due in part to the dispersion of the intermetallic nickel compound as a precipitate through the aluminum matrix. The precipitate tends to fix the dislocation points that occur during the cold working of the wire formed from the alloy. Looking at the intermetallic nickel compound precipitation in the cold drawn wire, it is observed that the precipitates are oriented in the direction of drawing. In addition, it will be appreciated that the precipitates may be rod-like, plate-like or spherical in configuration.

Other intermetallic compounds may also be formed depending on the components of the melt and the relative concentrations of the alloying elements. These intermetallic compounds are: Ni2Al3, MgCoAl, Fe2Al5, Co2Alg, Co1 + Al13, CeAl2, CeAl2, VA1n 'VA17 »VAlg, VA13, VA112, Zr3Al, Zr2Al, LaAl ^, LaAl2, Al3 * Co2A15, FeNiAlg.

12,594 2 3

The intermetallic iron-aluminate compound also contributes to the adhesion of dislocation sites during cold working of the wire. Looking at the intermetallic iron compound precipitation in the cold drawn wire, it is found that the precipitates are substantially evenly distributed throughout the alloy and have a particle size of less than 1 micron. If the wire is drawn without any intermediate emissions, the particle size of the intermetallic iron compounds is less than 2000 A.

One characteristic of high-conductivity aluminum alloy wires that has not been shown by historical tests for tensile strength, percentage elongation, and electrical conductivity is a possible change in properties as a result of increases, decreases, or fluctuations in the temperature of the strands. It is obvious that the maximum operating temperature of a thread or series of threads is affected by this temperature characteristic. This property is also very important for fabrication because many insulation processes require high temperature thermal curing.

It has been found that the aluminum alloy wire of the present invention has a thermal stability property that exceeds the thermal stability of conventional aluminum alloy wires.

For the sake of clarity, the terminology used in this application is explained as follows:

Aluminum alloy rod - a solid product that is long in cross section. Usually the cross section of the rod is between 7.62 cm and 0.953 cm.

Aluminum alloy wire - a solid inverted product which is long in cross-section, rectangular or rectangular with sharp or rounded corners or edges, or round, regular hexagon or regular octagon and having a diameter or maximum perpendicular distance between 0 and 50 00787 cm.

Although the present invention has been described in detail with particular reference to its preferred embodiments, it is to be understood that variations and modifications may be made within the spirit and scope of the invention described herein and defined in the appended claims.

Claims (11)

1 3 59423 An electrical conductor consisting of an aluminum alloy, characterized in that it has an electrical conductivity of at least 57% according to the IAC standard and in that the alloy contains substantially 0.2 to 1.6% by weight of nickel, 0.3 to 1.3% by weight of iron, 97 to 99.5 % by weight of aluminum, less than 0,1% by weight of cobalt and up to 2% by weight of at least one other alloying material selected from the group consisting of: Magnesium Yttrium Rhenium Copper Scandium Dysprosium Silicon Thorium Terbium Zirconium Tin Erbium Serium Molybdenum Neodymium Nhodium Neodymium Wolfram Boori Lanthanum Chrome. Thallium Tantalum Bismuth Rubidium Cesium Antimony Titanium Vanadium Carbon Electrical conductor according to Claim 1, characterized in that it has an electrical conductivity of at least 58% according to the IAC standard. Electrical conductor according to claim 2, characterized in that said other alloying material is selected from the group consisting of: magnesium, silicon, tantalum, thorium, zirconium, yttrium, carbon, copper, niobium, scandium or a rare earth metal or two or more of the aforementioned substances. alloys. Electrical conductor according to claim 2, characterized in that about 0.5 to about 1% by weight of nickel, about 0.4 to about 0.8% by weight of iron, about 0.1 to about 1.5% by weight of other alloy material and about 97.8 to about 99.2 weight percent. Electrical conductor according to Claim 2, characterized in that the alloy is formed (in weight percent) by nickel 0.6 to 0.8%, iron 0.45 to 0.65%, magnesium 0.03 to 0.1% and aluminum 97.8 - 99.2%. Electrical conductor according to Claim 2, characterized in that the alloy is formed (in weight percent) by nickel 0.6 to 0.8%, iron 0.45 to 0.65%, cobalt 0.03 to 0.1% and aluminum 97 .8 - 99.2%. Electrical conductor according to Claim 2, characterized in that the other dopant consists of magnesium 0.001 to 1%, copper 0.05 to 1%, silicon 0.05 to 1%, zirconium 0.01 to 1%, niobium 0.01 to 2 %, tannal 0.01 to 2%, yttrium 0.01 to 1%, scandium 0.01 to 1%, thorium 0.01 to 1% rare earth metals 0.01 to 2% or carbon 0.01 to 1 % or mixtures of two or more of the above. Electrical conductor according to Claim 7, characterized in that the alloy contains iron aluminate particles with a size of less than 200 nm. Electrical conductor according to Claim 1, characterized in that it is in the form of a rod. A method of manufacturing an electrical conductor according to claim 1, characterized in that from about 0.2 to about 1.6% by weight of nickel and from about 0.3 to about 1.3% by weight of iron, from about 97 to about 99.5% by weight -% of aluminum and less than 0,1% by weight of cobalt up to about 2% by weight of other alloying elements which are magnesium, copper, silicon, zirconium, cerium, niobium, hafnium, lanthanum, tantalum, rhenium, scandium, thorium, tin , molybdenum, zinc, tungsten, chromium, bismuth, antimony, vanadium, yttrium, terbium, erbium, neodymium, indium, boron, thallium, rubidium, titanium, carbon, cesium or dysprosium, are continuously cast into the groove in the circumference of the rotating castor, the groove portion of which is covered by a metal belt rotating around the wheel and a hot-rolled casting alloy substantially immediately after casting substantially in the state in which it is cast to form a continuous bar. Method according to Claim 10, characterized in that the rod is then drawn as a conductor on traction plates without intermediate annealing. 59423