DE3012009A1 - METHOD FOR PRODUCING SEMI-FINISHED PRODUCTS AND FINISHED PARTS FROM AN ALMNSI ALLOY - Google Patents

Description

METALLGESELLSCHAFTAG Pfm., 03/21/1980

Reuterweg 14 MLK / OKU

6000 Frankfurt / Main 1
Prov.No. 8453 AIu

Process for the production of semi-finished products and finished parts from an AlMnSi alloy

The invention relates to a method for the production of semi-finished products and finished parts from a AlMnSi alloy, which at room temperature has a tensile strength of at least 120 N / mm and an electrical

have a thermal conductivity of at least 29 m / mm and at which these minimum values are reversibly retained in the application range up to 450 ° C.

The standardized E-Al and E-Al-Mg-Si standard materials are used in Germany for guidance purposes. E-Al In condition F 16 according to DIN 40 501 it has a very high electrical conductivity for aluminum materials

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of at least 34.5 m / _flmm, but on the other hand only a very low strength. By strong strain hardening tensile strength values can be in this material going from about 180 N / mm (within the state F 17 according to DIN 40 501), however, this strength can be really exploited only in a temperature range up to at most 8O ⁰ C, because at higher temperatures Depending on the duration of exposure, a softening to a completely soft state must be expected. For this

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Due to the application for e-Al for overhead lines for example, is limited to a limit temperature of at most 8O ⁰ C.

The second common material, E-Al-Mg-Si, Curing can result in minimum tensile strength values

of 215 N / mm can be achieved, but at the same time the electrical conductivity is reduced to a minimum value of 30 m / jQ-mm. But even with this material is by prolonged heating at temperatures above 8O ⁰ C, the risk of a gradual softening by aging, the tensile strength

drop to 100 N / mm in the completely soft state can.

It should also be taken into account that an application limit temperature for a material also means that Care has been taken to ensure that objects made from them are made and processed must be that the limit temperature is not exceeded. This is the case with materials, for example a limit temperature of 80 C is not possible to apply a plastic insulation, its processing requires higher temperatures. Furthermore, it is not possible to enamel or solder such materials.

This resulted in the task of providing an aluminum material which, in terms of tensile strength and the electrical conductivity is comparable with the known materials, in which these properties but retained reversibly up to a much higher application temperature. The aim is so primarily not an improvement in the train

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strength values or the electrical conductivity pls such, but the provision of an aluminum material having similar minimum values, whose processing and application is not limited as in the known materials to temperatures no higher than 8O ⁰ C.

This object is achieved according to the invention in that the following composition is made from an ingot 10

0, 2 until 2 S. 0, 6th until 3 5 0, 2 until 1 S. 0 until 0, 2 9 0 until 0, 2 pp 6 manganese i silicon & Iron i copper i magnesium

Remainder aluminum, including total

a maximum of 0.2% unavoidable manuf Position-related impurities

after the usual annealing the ingot at 400 to 620 ⁰ C by hot and / or cold forming the desired semi-finished or finished parts are produced and that these are subjected finally at 300 to 450 ⁰ C annealing to complete recrystallization.

The semi-finished or finished products prepared by this process have the advantage that they are in a thermodynamically stable state and that therefore the set of strength and conductivity values with certainty even at a temperature stress above 8O ⁰ C, at least up to the respective temperature applied the Rekristaiiisationsglühung reversible remain.

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The method has the further advantage that it optionally allows the setting of optimal conductivity values or optimal strength values. For optimum conductivity values, the recrystallization annealing is preferably carried out at 30O ⁰ C or just above, while for the setting of optimal strength values the recrystallization annealing is preferably ^{carried out at 45O 0} C or just below.

Further details and advantages are explained in more detail with the aid of the diagram shown in FIG. In this are the values measured at room temperature for the tensile strength and the conductivity of an inventive semi-finished product produced depending on the two-hour recrystallization annealing applied temperature. In the work-hardened state, the material has a tensile strength of

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approximately 250 N / mm with an electrical conductivity of almost 50 m / jClmm. With these values, the material treated according to the invention is absolutely comparable with E-Al-Mg-Si in the hardened state. After recrystallization annealing at 300 ^° C., the tensile strength drops to the specified minimum value of 120 N / mm, while the electrical conductivity increases to 30.7 m / mm. At a recrystallization annealing of 300 to 500 ⁰ C, the tensile strength increases about steadily to about 16O N / mm, while the electrical conductivity falls also almost continuously to below 28 m / Xlmm. The exploitable under the specified conditions, the temperature range for the recrystallization annealing is therefore expediently limited upwards to 45O ⁰ C in order to avoid an excessive drop of the electrical conductivity. At this annealing temperature is the

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ability at just under 29 m / XLmm, while the tensile

strength has already risen to over 140 N / mm. The diagram shows that for the respective application by varying the temperature of the recrystallization annealing an optimal combination of tensile strength and electrical conductivity is set can be. Let it be repeated once more that the properties set in this way are independent of the Temperature at which the semi-finished products or finished parts are used, reversibly retained because the material structure in a thermodynamically stable one State.

The diagram also shows that the material can of course also be used without prior recrystallization can be used when a particularly high tensile strength is required and room temperature for use is certainly not significantly exceeded. To that extent, however, the material would be the same restrictive Subject to conditions, such as the known materials mentioned at the beginning.

In the case of semi-finished products and finished parts that have been manufactured by the method according to the invention, one is always on the safe side; the minimum values for strength and after complete recrystallization electrical conductivity are also guaranteed if, during processing, such as applying a Insulation, enamelling, soldering etc. higher temperatures must be applied.

- 6 claims

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Claims (3)

patent claims 1. Process for the production of semi-finished products and finished parts from an AIMnSi alloy which have a tensile strength of at least 120 N / mm and an electrical conductivity of at least 29 m / Amm at room temperature and which have reversible ^{minimum values in the application range up to 450 ° C} remain, characterized in that from an ingot the following composition 0.2 to 2 % manganese
0.6 to 3 % silicon 0.2 to 1 % iron
0 to 0.2 % copper
0 to 0.2% magnesium, the remainder aluminum, including a total of at most 0.2% unavoidable positional impurities after the usual annealing the ingot at 400 to 620 ° C by hot and / or cold forming the desired semi-finished or finished parts are produced and that these are subjected finally at 300 to 45O ⁰ C annealing to complete recrystallization. 2. The method according to claim 1, characterized in that the recrystallization annealing is carried out ^{at about 300 0 C to achieve optimal conductivity values.} 3. The method according to claim 1, characterized in that the recrystallization annealing is carried out at about 450 ° C to achieve optimal strength values. 130CK1 / 01Ö9 ORIGINAL INSPECTED