DE1558622C - Alloys based on copper - Google Patents

Description

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The invention relates to much improved alloy and seldom reach over 21.0 kp / mm ² . Accordingly

The alloys according to the invention have ments based on copper with a content of accordingly

Zinc, aluminum and cobalt, whereby these alloys have high yield strength values in the cold-worked state,

significantly improved physical properties, for example 62.3 kp / mm ² and more after one

have and for a wide range of applications overall 5 50 _^0/0 <gen cross-sectional decrease in Kaltverfor-

are suitable, including castings, forgings, pressings, whereas common alloys are usually

billets and hot-rolled or cold-rolled or drawn prongs in the range from 35> 2 to 52.7 kp / mm ²

products belong. Have the improved alloys according to.

of the invention are particularly for use in addition and as an essential property are the

Suitable for forgings. io alloys according to the invention due to a high

Numerous attempts have been made over the years to identify malleability. If you use that up

the strength properties of ductile brass to deformable 70/30 brass as a yardstick

improve without losing its deformability. the alloys according to the invention have a comparative

These attempts focused on the use of bare deformability. This is particularly surprising

a wide variety of alloy additives to 15 in view of the high strength of the alloys

to achieve this end. Some of these alloy components according to the invention.

kits are quite expensive and add to the cost of. These surprising properties at a price die Alloy significantly. Values alloy are particularly unexpected in Anbe-Also in technology many unusual attitudes of extensive knowledge in this field, borrowed thermomechanical processes thoroughly under- ao trying to approximate these properties, the strength properties had been unaffected!

to improve deformability. The alloys according to the invention belong to

The types of brass developed by the technology type of special cast brass, which is known

are generally multiphase alloys - besides copper and zinc there is also some aluminum

genes with limited ductility and cold formability. 25 included. Such types of brass basically have

Such alloys are one of the following structures for cast use: (1) An alpha structure

Pieces or heat-processed products are very suitable. (face-centered cubic) or (2) a mixed structure

Despite this extensive research, Alpha Plus has a limited amount of a Bcta structure

over the years a 7O / 3O brass as the best and (cubic space numerals).

Most economical alloy atf copper base for an 30 The addition of aluminum to copper-zinc alloy under severe deformation conditions, stanchions has long been the predominant factor in reinforcing their strength. 'The effect on such alloys is known. Accordingly, it is the primary object of the invention, one disadvantage of aluminum addition is that it is improved To create copper-based alloy. saturated alloys with an alpha phase that the Furthermore, it is the aim of the invention to have alloys with the highest strengths, small changes in the To create copper base, the improved solid aluminum content in general major changes limits both in the fully annealed and in the cold worked ductility and strength result. This have formed state. major changes result from the structure on-addition The aim of the invention is to provide such improved construction of the saturated alloy, which deals with the aluminum alloys to create a copper-based 40 which significantly changes the improved nium content. For example, a Increased strength properties with "a minimal change in the aluminum content of one percent show loss of deformability. ,. an increase in the beta phase content of up to 33 percent

Finally, another object of the invention is the cause.

Creation of an improved alloy based on copper according to the invention was surprisingly based, this alloy by relatively 45 found that the addition of cobalt is characterized in the low cost range, so that it economizes 0.1 to 3% the disadvantages of the ternary Copper-aluminum for use on a large scale, one-nium-zinc alloys removed in such a way that the properties can be set. - ■ shafts and the structure more uniformly based on one another. Further goals and advantages of the invention are based. reversible range are in the Altiminium content. Also the following emerges. This results in a very pronounced grain refinement effect. It has been found that the stated objectives can easily be achieved by adding cobalt, which can be achieved in an advantageous and suitable manner. She is.

improved alloy according to the invention.

of the following components in the cited comment fall into the cited range. the

range, with all percentages based on the value 55 copper content must be in the range of 67 to 80%,

Not related: 15.0 to 31.0% zinc, 1.0 to 5.0% preferably falling from 70 to 76% . It sinks below 67%

Aluminum, 0.1 to 3% cobalt, remainder 67 to 80% strength noticeably and over 76% one meets one

Copper and manufacturing-related impurities. additional phase in saturated alloys known as

It was found / that the gamma phase according to the invention is designated and a complex one

Alloy has significantly improved physical properties - 60 cubic structure , which increases the ductility of the alloy

Shafts are limited with minimal loss of deformability.

shows. For example , the improved alloy similarly has the zinc content within the range

according to the invention, yield strength properties in the range from 15.0 to 31.0%, preferably from 19 to

fully annealed condition on the order of 28%. The aluminum content must be in the range of 1.0

31.6 kgf / mm ² and above while maintaining conventional 65 to 5.0%, preferably from 2.0 to

Copper based alloys for use as 4.5% and the cobalt content is in the range of 0.1 Moldings usually yield strength values in the full range to 3%, preferably from 0.1 to 1.0%.

Annealed condition in the range from 7.0 to 17.5 kp / mm ² . To achieve maximum ductility with the same

3 4

In general, the cobalt content according to the invention should have 0.1 to 1.0% alloys, making a structure of alpha plus particle phase, while to achieve greater strength or alpha plus beta plus particle phase and are and are of lower diictility the cobalt can occupy higher levels in a wide range of different areas ranging up to 3%. Applicable over these 5. Because of their great strength and the kbbait content, the properties of little deformability are also improved, since an excess of cobalt in the form of parschmiedeter is used. The oxidation resistance of the elementary metal or, as elementary speed and castability of the alloys according to the ErKobalt in addition to an intermetallic compound with invention is excellent and can be used widely. appears, whereby the diictility io dung as a high-strength, inexpensive foundry alloy decreases. ■. In general, the alloys with low shafts make them appear just as suitable for forgings as for cobalt-content materials of great strength and compacts. Generally high ductility, while the alloys with a better combination of mechanical higher cobalt content have higher strength, but 15 properties at lower cost due to the lower diictility, boulder-like alloys obtained: than they are in the composition of particular alloys any currently produced Alloys within the specified ranges will continue to be available regardless of the price.
restricted by that at a copper content- Das. Processing the alloys of the invention limit the aluminum content to about 69% of the preferred 20 requiring no unusual treatment. For example, in the range from 1.2 to 3.2%, so that the game, a sheet is produced as follows: Melting properties of high ductility together with the and casting strength will be safely retained under similar conditions, and that carried out at one as with brass alloys. The iin copper content limit of about 74% that of aluminum. indirect permanent mold casting is particularly suitable. The content, preferably in the range of 3.0 to 5.0% from hot rolling, is easily accomplished using the same reasons. Partial regulation of common brass rolling processes. In the case of the aluminum content during the various rapid cooling, a structure can be obtained which is not in equilibrium with the copper contents between the specified limits, which should preferably be carried out when cold. rollability impaired. This can be further overcome by tempering, preferably in the range of 538 to 649 ° C, the properties of the aluminum content to the zinc should be overcome - whereby appropriate equilibrium ratios of content are achieved according to the following equation in relation to alpha and beta phases,
be set: It was observed in the processing of the alloys according to ⁰ I Al = - 0 29 ° / Zii -1-92 + 1 35 ^ ^er invention that they are aimed at the elimination of '''-' 35 of the stresses generated by cold working The alloys according to the invention are shown unusually well in the tempering at low temperature drawings that ^{respond isothermally (500 °} C.). Usually, alloys with a constant cobalt content (0.5%) of the copper base that have been intensively cold worked can show quaternary phr. show an increase in the yield strength of up to 15% if F i g. 1 shows the relative position of the alloys at temperatures below the recrystallization temperature according to the invention on the ternary phase diagram. temperature can be left on. This increase is usually there; ^'■■':; -also only within a fairly narrow range of FIG. 2 shows the hatched section of FIG. 1. Aiilaßtemperaturen (27 to 6O ⁰ C) of practical leg g to Fi: 1 and 2, the solid line the interpretation. In the case of the alloys according to the invention, the limit of the alpha phase is represented. The dashed line in FIG. 45 shows increases in the yield strength of 30 to 40% after FIG. 2 provides the alloys of the invention. Tempering material found to be a cold rolling constant grade of 0.5% cobalt. Similar reduction of 50%. In addition, the diagrams can easily be worked out for other cobalt boundary regions recovery in a broader temperature range (82... Up to 110 ° C), which increases the commercial applicability of the alloys according to the invention in the 50s. The magnitude of the improvement in the cold-worked and in the annealed state is strength properties is shown in the examples aiifge either (1) a matrix of fine-grain, planar. ■ '. _

centered cubic alpha phase (saturated or almost due to the stabilizing influence, of cobalt

saturated), or (2) a saturated aliphatic phase plus on the vessels are the properties from

Beta phase, with both the structure (1) and the crystallization-tempered material. 'Also over

Structure (2) very fine particles of an intermetallic one \ .ausge'dehhien '·: temperature range ·' .istcjbil / - to

Connection and / or elimination by and example, the yield point fell. Of a typical 'co-

contains dispersed through. ;, ';.:;;: / ·. . :, ^; /. weight "only from 45 kp / him ² 'to 42.2 kp / irim ²

■■ · The alloys according to the invention can be added. after starting for one hour ^; 371 and 538 ° C; the

in addition to the mentioned part. ''! materials.: usual tensile strength remains in a similar way.

uiireinigungeij usually contained in commercial while that. Elongation at break steadily above the same usual _; . Pre-grain alloys based on copper .: '·; ■ temperature range increases. ,. · , - \ '"'. ; ';·",Ί:''' ^ '"''

Such crimps are: lead, tin, phosphorus, egg another special characteristic of the invention

Iron, manganese, nickel and silicon. There is a very pronounced disposition to the appropriate alloys.

Zinkuhg in a 'corrosive environment on a 65 improve corrosion resistance.' The Kiipfer

Mjnirftum To hold _1; can, an addition of arsenic, zinc-brass types _{are opposite: Spanniingsriingsriß-}

Phosphorus and / or antimony ih, an amount of 0.02 susceptible to corrosion if they are certain corrosive

to 0.10% may be desirable. Are exposed to influences. This susceptibility is the

Zinc content proportional, and therefore alloys containing more than 15% zinc are rarely used for applications used under tension in a corrosive environment. It was found that the addition of cobalt modified aluminum-containing brass types have a greatly improved resistance to chip corrosion cracking when compared to the binary copper-zinc alloys. This Behavior is evident from the following examples. Coupled with this resistance to Stress corrosion cracking is a high level of general corrosion resistance.

Be i s ρ i e 1 1

Alloys of the compositions tabulated below were made from cathode copper, plate zinc, either metallic cobalt or a copper-cobalt master alloy or an aluminum-cobalt master alloy and balls made of aluminum metal. The production was carried out in the following sequence. The cathode copper pieces were melted under charcoal, a part or the total amount of the desired aluminum metal was added and stirred in, Cobalt in the form of balls of the master alloy made of copper with 15% cobalt or the master alloy Aluminum with 30% cobalt was added next and the melt kept at temperature until the complete dissolution occurred, after which pieces of zinc were added and introduced. The melt one Temperature of about 1093 ° C was poured into a cast iron mold and held in it until solidification. The ingots obtained were reheated to 816 to 899 ° C. and had a thickness of 4.445 cm 0.762 cm hot rolled, after which the temperature is about

ίο was 538 ° C. The material was then cold rolled up to 0.305 cm, tempered at 538 ° C for 1 hour and cold-rolled to 0.076 cm. The material was in the last obtained thickness reduced by 50% at 0.076 cm and also after tempering at various Temperatures examined.

For comparison purposes, a commercially available 7O / 3Oer brass and copper-zinc-aluminum alloy was subjected to the same treatment, with the difference that the 7O / 3Oer brass was between annealed at 427 instead of ^C at 538 C.

The properties are summarized in the following table, i.e. H. the yield point remaining at 0.1% Elongation, tensile strength and the percentage elongation at break in both cold-rolled and

let state. .

composition table train fracture I. train ° c • - 1 hour at 649 ⁰ C.
left on train fracture in percent by weight Cold rolled to 50% firm
speed deh
tion firm
speed fracture Cf r / v l · " firm
speed deh
tion Legie Stretch-- kp / mm ² % 1 hour at, 538
left on kp / mm ² deh
tion OI FC *. K. "
border kp / mm ² 7o tion 73.25 Cu 3.75 Al border 90.89 2.5 61.16 7o kp / mm ² 26.35 35 0.44 Co 22.6 Zn kp / mm ² border 33 36.20 I. 76.9 Cu 4.6 ΑΓ 63.62. 93.85 2.2 kp / mm ² 58.70 0.4Co 18.1Zn. 42.18 35.2 II 69.5 Cu 1.7 Al. 69.85 81.20 2.2 50.62 0.4 Co 28.4 Zn 39.37 *) 34.5 III 73.3 Cu 3.5 Al 61.16 88.68 2.3 55.90 55.90 38 0.4 Co 22.8 Zn 30.58 *) 58.99 39.5 34.45 IV 74.0 Cu 4.0 Al 62.28 91.39 2.1 62.92 34.5 60.46 32 1.0Co 21.0Zn 34.96 *) 53.43. 26th 40.27 V 75Cu 4.3Al 65.38 89.63 2.0 40.77 58.42 37.5 56.66 37.4 0.2Co 20.5Zn 43.94 37.6 29.95 VI 76Cu 4.0Al 65.38 80.14 2.0 31.28 *) ₍ 45.69 20Zn. 37.19 50.62 57 VII 70Cu 30Zn 62.57 62.28 3.5 37.26 39 18.98 50 VIII 52.37 28.82 **) 15.32 **)

*) Tempering at 593 ° C in a cycle of 17 hours for 3 hours. *) 1 hour at 427 ° C. · '. - "^;

/'■·■.'■ ■ ·· 'Example 2:

To demonstrate the unusually good response to starting at low temperatures Alloy IV from example Γ tempered at 2O4 ° C for one hour. The following properties were measured:

•,. Strength properties

50% cold rolled: ^;: ^. ^ Λ "

Stretch limit.........:........;. 62.88 kg / mm ⁸

(0.1% permanent elongation)

Tensile strength ...................: 88.68 kp / mm ²

Elongation at break ................... '' 2.3%

50% cold rolled - \ - 1 hour at 204 ⁰ C
Yield strength 94.20 kp / mm ²

Tensile strength ..............; ..... 103.55 kp / mm ² elongation at break ...... ........... '.. 1 , 4%

. · ■ ■■ '■; - ■; ■; ■■■ .- ■ .-. ■ Example ^ ¹ · ■. "'. ■■■' · ■;: ■ ':"' ■■ '

Various of those prepared according to Example 1 Alloys were tested for ductility using two common measurement methods, d. H'. the limit ratio determination in deep drawing and the cup deep drawing process according to Olsen for the Determination of deep drawability. The results show that the improved alloys according to FIG Invention with regard to deep-drawability almost on 7O / 3Cer brass come up (comparison alloy VIII), and in the cup deep drawing test or in the Determination of the limit drawing ratio are only slightly less deformable than 7O / 3O brass.

Table II

alloy

III
IV
VIII

Limit draw ratio

2.276
2.270
2.260

Claims (7)

Claims: Olsen bulge height; 0.950 cm 1.016 cm 1.067 cm 10 1. Alloy based on copper, characterized in that it is made of 15.0 up to 31% zinc, 1.0 to 5.0% aluminum, 0.1 to 3.0% cobalt, the remainder 67 to 80% copper and production-related Consists of impurities; 2. Alloy according to claim 1, characterized shows that the contents of aluminum and zinc in the ratio according to the equation% Al = -0.29% Zn + 9.2 ± 1.35 to each other. 3. Alloy according to claim 1 to 2, characterized in that the zinc content is 19 to 28% amounts to. 4. Alloy according to Claims 1 to 3, characterized in that the aluminum content Is 2.0 to 4.5%. . 5. Alloy according to claims 1 to 4, characterized in that the cobalt content is 0.1 up to 1.0%. 6. Alloy according to claims 1 to 5, characterized in that the copper content is 70 to 76%. 7. Alloy according to claims 1 to 6, characterized in that it additionally 0.02 to Contains 0.10% arsenic, phosphorus and / or antimony. 1 sheet of drawings