CN1081245C

CN1081245C - Preparation of boronic aluminium alloy with high conductivity

Info

Publication number: CN1081245C
Application number: CN99104364A
Authority: CN
Inventors: 刘顺华; 王桂芹; 高洪吾; 周文龙; 李长茂
Original assignee: Dalian University of Technology
Current assignee: Dalian University of Technology
Priority date: 1999-04-15
Filing date: 1999-04-15
Publication date: 2002-03-20
Anticipated expiration: 2019-04-15
Also published as: CN1271024A

Abstract

The present invention relates to a manufacturing technology of high-conductivity aluminium alloy containing boron, which is suitable for the manufacturing process of aluminium bars in the field of electric wires and electric cables. The present invention adds 0.05% to 0.13% of boron to 99.5% to 99.7% of industrial pure aluminium for making bars and then carries out annealing or self annealing of (200 to 320 DEG C)*(1.5 to 3h), and moreover, the present invention is matched with the purification treatment of aluminium liquid by inert gas and the filtering technology of foam ceramics so as to cause the specific resistance of an aluminium conductor to reach (2.72 to 2.74)*10<-8>omega m, the strength of the aluminium conductor is maintained to be equivalent to the strength level of industrial pure aluminium, and the plasticity of the aluminium conductor is 10 to 20% higher than that of industrial pure aluminium. The strength is matched with the plasticity well so as to cause the alloy to have good comprehensive mechanical property.

Description

A kind of manufacture method of high conductivity boracic aluminium alloy

The invention belongs to the manufacture method of conductive aluminum in the metal material field, be specially adapted to the manufacturing processed of aluminium bar in the electric wire field.

In the research and manufacturing processed of conductive aluminum, reduce the resistivity of aluminium, improve its electroconductibility, be the target that people constantly pursue always.At present, the electric conductivity standard of the commercial-purity aluminium of Gong Rening is 61%IACS in the world, and the electric conductivity of regulation aluminium only is 59.45% in China's standard.In the various factors that influence aluminium electroconductibility, chemical ingredients is one of important factor.Electroconductibility with the method raising aluminium that adds alloying element has two kinds of approach at present, the one, in aluminium, add rare earth, the research of this respect has obtained certain progress, but also exist many contradiction, as " rare earth is to the influence of aluminium conductor electroconductibility " paper that " China YouSe Acta Metallurgica Sinica " the 1st phase in 1992 delivers, think that rare earth does not reduce the effect of the resistivity of aluminium.From the feedback information that aluminium bar manufacturers such as Guizhou Aluminum Factory, Jilin huge rock aluminium manufacturer receive, therefore the result of use instability holds a negating attitude to the effect of rare earth.The 2nd, in aluminium, add boron, normally in aluminium, add≤0.05% boron at present, it is called as boronation and handles as a kind of industrial removal of impurities means, is employed.As the conductive aluminum 1350E of the U.S., be exactly in 99.5% aluminium, to add≤0.05% boron, its electric conductivity reaches 62%IACS.In the article of " handle improve the electrical aluminum rod electric conductivity with the aluminium liquid boronation " delivered in " electric wire " second phase in 1984, Shengyang Electrical Cable Factory and Shanghai Electrical Cable Research Institute cooperation have been introduced, with the method that adds potassium fluoborate multiple import, homemade aluminium are carried out the result of study that boronation is handled, the electric conductivity that various aluminium can reach after boronation is handled is all between 61%～62%IACS.

The method that the objective of the invention is to invent a kind of process stabilizing, can produce the higher aluminium conductor of electric conductivity to improve the power transmission efficiency of transmitting line, reduces meaningless energy consumption in the transmission of electricity process.

Technical scheme of the present invention is by self-annealing or annealing process after adding 0.05%～0.13% boron and making bar, and cooperates purification, the filter process of aluminium liquid, improves the electroconductibility of aluminium.

Specific embodiment of the present invention is as follows:

Implementation condition is an aluminium bar continuous casting and tandem rolling production line, in the middle part of the chute of preceding case, be provided with purifying treatment groove and filter vat at smelting furnace or maintenance stove, the filter vat size should be complementary with rolling mill speed, and the purification tank size is design in 8～15 minutes by aluminium liquid treatment time in groove.Be provided with insulation kiln or stay-warm case in milling train closing quotation place.

(1) original aluminum liquid composition requires: purity is 99.5%～99.7% aluminium, Si≤0.08% wherein, and Fe≤0.20%, (Cr+Ti+V)≤0.03%.

(2) aluminium liquid carries out rough purification and handles in holding furnace, and makes temperature be controlled at 750～800 ℃, adds the Al-B master alloy, makes to add the boron amount and account for 0.05%～0.13% of aluminium liquid.

(3) stir 2～5min after adding the Al-B master alloy, static 5～20min comes out of the stove.

When (4) aluminium liquid is flowed through the purifying treatment groove, it is carried out purification handle.Purifying treatment adopts double-deck paddle---and argon bottom-blowing refining plant, argon flow amount are 15～20L/min, and the paddle rotating speed is 450～700r/min.

(5) aluminium liquid flows into filter vat after degassing and purifying, and the aluminum oxide foam ceramic filter plate that 20 thick～30PPI of 50mm (PPI is meant the hole count that is had on the per inch length) is housed in the filter vat filters.

(6) case entered continuous caster before the aluminium liquid after the filtration treatment flowed into.

(7) controlled chilling intensity makes aluminium bar closing quotation temperature at 200～320 ℃, directly enters in the stay-warm case that is incubated kiln or insulating lining is housed after the closing quotation of aluminium bar and is incubated 1.5～3h, carries out self-annealing; Or the 1.5～3h that in heat treatment furnace, under 280 ℃～300 ℃ conditions, anneals.

Below provide optimum implementation of the present invention:

Described in specification sheets: in holding furnace to 99.7% fine aluminium, adjust temperature, make it remain on 750～800 ℃, add aluminium boron master alloy, make aluminium liquid boron-containing quantity in 0.05%～0.09% scope, stirred 2～5 fens, and static 10～20 minutes, came out of the stove, aluminium liquid flow to purification tank, use double-deck paddle---the degasification of argon bottom-blowing refining plant, argon flow amount 15～20L/min, 20PPI foam ceramic filter.700 ± 10 ℃ of teeming temperatures, 450～480 ℃ of breaking down temperature, strand speed 2.3～2.7m/min, 260～300 ℃ of closing quotation temperature, closing quotation back aluminium bar directly enters the continous way insulation kiln that the bottom is covered with track, and insulation 2h carries out self-annealing.The aluminium bar resistivity of producing can reach (2.72～2.74) * 10 ^-8Ω m, σ _b=100～108MPa, δ=14～20%.

Effect of the present invention is that the resistivity that makes aluminium conductor is reduced to (2.72～2.74) * 10 ^-8Ω m, the level of rafifinal near 99.99%, and intensity has kept the strength level of commercial-purity aluminium; The plasticity ratio commercial-purity aluminium exceeds 10～20%.Use this aluminium conductor in transmitting line, its economic benefit is mainly reflected in and reduces a large amount of electric energy losses that electrical network causes because of resistivity is too high.According to statistics, at a 100KM, on the ultra-high-tension power transmission line of 50KV, the every reduction by 1% of resistivity, the electric energy that can save every year is 45.2 ten thousand degree.The aluminium conductor replacement resistivity of producing with the technology of the present invention is international standard value 2.8264 * 10 ^-8The aluminium conductor of Ω m, resistivity have reduced (2～3) %, and in above-mentioned such circuit, the electric energy that can save every year is (90～135) ten thousand degree.

Claims

1. the manufacture method of a high conductivity boracic aluminium alloy, it is characterized in that: be to add boron in the melting process of commercial-purity aluminium, it adds the boron amount is 0.05%～0.13%; The molten aluminium that adds behind the boron must be through purifying and filtering, be provided with double-deck paddle argon bottom-blowing refining plant in its purification tank, argon flow amount is 15～20L/min, and the paddle rotating speed is 450～700r/min, and the thick 20～30PPI aluminum oxide foam ceramic filter plate of 50mm is installed in the filter vat; Molten aluminium is made the aluminium bar through continuous casting and rolling, and the closing quotation temperature of aluminium bar is 200～320 ℃, and is incubated 1～3h under this temperature.

2. the manufacture method of the described a kind of high conductivity boracic aluminium alloy of claim 1, its feature also is: in the continuous casting and rolling process, the closing quotation temperature of control aluminium bar is 200～320 ℃, directly puts into the insulation kiln after the closing quotation of aluminium bar or stay-warm case is incubated 1.5～3h, carries out self-annealing.