DE2129101A1 - Aluminum bronzes and processes for their processing - Google Patents

Description

"Aluminum bronzes and processes for their processing"

Priority: June 11, 197O ₅ V.St.A., No. 45 441

Copper / beryllium alloys are excellent because of their Properties such as high tensile strength and yield strength in.

"broad scope

e.g. for live. S'eöevn, Kon-

ei η-res et Z.
clocks and membranes / JYes these alloys are "relatively expensive, there is great interest in cheaper alloys with equivalent properties, which are also a substitute for cheap. ■ Copper alloys with low strength.

Aluminum bronzes are well known at elevated temperatures

kaiin

easily deformable, i.e. these alloys can be easily hot-rolled, forging or extrusion when they are entirely or predominantly in the ß-phase at these elevated temperatures are present. The Aluminiurabronzan * 's: iηd very versatile Tcrrv.-onci-

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. bar, e.g. for corrosion-resistant ropes such as Kühlerronru or Valves, break-proof and fatigue-resistant parts, - «io springs. e.g. Bourdon springs, heat-resistant parts with good Iloch temperature corrosion resistance, such as parts of internal combustion engines »wear-resistant parts such as lines or guides, as well as Molds for metal or glass processing.

further
There is / interest in a method for processing

(hereinafter referred to as "super plasticity") of aluminum bronzes, the w these alloys, particularly high ductility or plasticity at elevated temperatures verleiht-, since the blank Aluminiumbronzeii to forints il-en process with high tensile strength with this property in particular according Vakuumverformungsmet ho.

The object of the invention was therefore to find new, cheap aluminum bronzes with improved mechanical properties, in particular greatly improved tensile strength and yield point; and with

rest
to create the same good / properties as those of other alloys of this type, as well as a processing method by which these aluminum bronzes are given a deformability or ductility at elevated temperatures that has hitherto been unattainable for alloys of this type. This object is achieved by the invention.

The invention thus aluminum bronzes, the ^DA: are characterized by that they are from 8 to 11.8 percent aluminum, 0.5 to 4 percent of cobalt, about 0.05 to 2 production ■ center of zirconium, 2u 0, f to 2 percent from "Manganese, remainder ^: ■ · ^:

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Copper and little hens . conventional impurities, exist and have a metallographic structure with a proportion of ß-phase of 5 to 100 percent, remainder cA phase, as well as a uniform fine grain size with a grain size below 0.05 mm.

The Λ1υι.: ΊΗί \ η. · ": 1:" Γοΐι; ίοη of the invention oind scha "tough and excellently deformable. They both have a surprise high tensile strength and yield strength as well as a good electrical conductivity .. the tensile strength reached Words from 84 to 105 kn / mm (in the artificially aged condition

112 to 126 kp / inm), the 0.2 percent yield strength values of 152.5 to 70 kp / mm "(in artificially aged condition 91 to 105 kp / mm *) · The electrical conductivity is about .10

V / ide r ο ta η (i . ^C ■ - up to 16 percent of the lACS Iiorm value (100 percent of the / Borm value

correspond to 0.15328 Ohm / m.β at 2O ⁰ O). The aforementioned properties are therefore similar to those of the beryllium / copper alloys mentioned.

Furthermore, the aluminum bronzes of the invention are good hard and hard Soft solderable, easy to weld, corrosion and stress corrosion resistant as well as fatigue-resistant.

The aluminum bronzes of the invention preferably have one liorngrösoe below 0.04 mm and preferably contain one Proportion of ß-phase from 85 to 100 percent. The alloy components zirconium and cobalt facilitate grain growth The achievement of grain concentration is thus inhibited. This grain refinement is based on the formation of a fine

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cobalt strands new dispersion of zirconium and / or Seilohen and has a macroscopic effect in an increased strength of the Aluminum bronzes of the invention.

Preferred aluminum bronze according to the invention contain 9.4 "to 10.4 percent, especially 9) 8 "to 10 percent aluminum as well 0.08 "to 0.15 percent zirconium, 0.8" to 1.5 percent cobalt and 0.5 "to 1 percent manganese.

Als'übliche impurities include aluminum bronzes erfindungsgeniässen w z _f B, magnesium, silicon, tin, lead, phosphorus, arsenic, antimony, bismuth ", silver, zinc and / or nickel.

There is now a preferred method for processing the aluminum bronze according to the invention! described which generally conforms with the method described in US Patent 3,287,180 method. .

First, the aluminum bronzes of the invention can be made according to conventional Melting methods and pouring them into bars, where ™ you just have to make sure that a well-trained, clean cast ingot with a homogeneous structure is obtained, the composition of which meets the aforementioned requirements. The cast ingot can then be thermoformed, for example by hot rolling at temperatures from about 538 to about

ο ⁴

1010 C, it is not important how you get the cast ingot on heats the hot rolling temperature range, and any conventional heating method or rate can be used,

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After hot rolling, the aluminum bronzes according to the invention should have the highest possible proportion of # -phase in accordance with the phase balance weight for the respective composition and, in addition, a relatively high volume proportion of the dispersion described above. The formation of a maximum proportion of .alpha.-phase is ensured by the fact that d ^- keeps ie either alloy during hot rolling or after at least 2 Hinuten at temperatures of about 565 to about 593 G ⁰ or glows. These temperatures can be set in a wide variety of ways. The aluminum bronze can be allowed to pass through the aforementioned temperature range, for example during normal hot rolling, by slow cooling and keep it at these temperatures for at least 2 minutes, but preferably longer.

After hot rolling, the aluminum bronzes become the invention

et ν * α

at temperatures below 26O ⁰ G, preferably from / -18 to 93 C, cold-formed, for example, cold-rolled. It is not important to be in

temperature - ^ v / which way the aluminum bronzes on the JCaltverformungstur cools, and the cooling can also be carried out at any convenient rate by using the Alumjnri umonzen e.g. by spraying quenched or in water or cool in the air. It is very surprising that the A3_uminium bronze of the invention are easily cold deformable. Aluminum bronzes with the aforementioned particularly preferred aluminum content (9t8 to 10 percent Al), up to a reduction in thickness 50 percent are cold-rolled, while aluminum bronzes, their aluminum content at the lower values. of the aforementioned general range (8 to 11.8 percent Al)

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- is, even up to a reduction in thickness of more than 50 - ^c / can be cold rolled. This surprising property is permitted

the use of the aluminum bronze of the invention for a new class of merchantable products. It is of particular importance that the Alumiriiumbrorizen the invention in the form of thin sheet on _above -ev; ickelten flush mountable - i.cn or films are available, since such products for which there is a great need, were not yet commercially available .

The thickness reduction made during cold rolling depends on numerous factors. If no further via] ζ steps are listed one can use the aluminum bronzes of the invention Cold roll to the end. The exact value of the reduction in thickness in cold rolling is not decisive and, like the number of rolling passes, depends on economic factors Processing considerations. About the hickening To keep as low as possible during cold rolling, the aluminum bronzes of the invention can be re-exposed to temperatures of the aforesaid hot rolling section and hot rolling before cold rolling them. One can use the aluminum bronzes of the invention in the form of cold-rolled sheets in aen Hendel.

After they have experienced the desired _i Dichenverrrii.nderung during cold rolling, the Aluminiiunbronzen of the invention may in lemperaturen of about 538 to about 76o ⁰ C, preferably about 558-593 ⁰ C, in particular from about 565-593 ⁰ C, annealed at a Increasing the annealing temperature also increases the proportion of ß-phase. and if not by, subsequent cooling

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len a. The highest possible proportion of '' X'-Phaoe is excreted becomes, wire, the degree of thickness reduction "in the following Cold rolling decreased. Ho is not decisive how to apply the aluminum bronzes of the invention to the the aforementioned happiness .ite: nperaturcn brings. One should use the aluminum bronzes Keep at least on ο / 2 minutes at the annealing temperatures. A preferred method is cold rolling Glow]] repeatedly, especially several times. The best results are achieved using 3 cycles of cold rolling and annealing. Particularly when using this method, you will form a fine body in the aluminum biofilms according to the invention Grain structure, which is superior to the aluminum bricks Gives skill «, - The aluminum bronzes of the invention can also in the annealed state, which also has a fine grain structure door and which guarantees maximum malleability, be put on the market.

After cold rolling, the aluminum bronzes of the invention can be annealed at temperatures of about 593 to 982 ° C. and then rapidly cooled. The annealing temperature to be used is inversely proportional to the aluminum content, ie the lower the aluminum content, the higher the annealing temperature. Aluminiumkc-onzen having an aluminum content within the above particularly preferred · range are annealed at temperatures of about 016-900 ⁰ C. The annealing time to be used is unimportant and only has to be sufficient to ensure that the annealed sheet has a uniform temperature. quickly until at least.

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imter
half about 538 C ,. ie / the eutectic .Transformation temperature, be cooled. In order to maintain this limit of Texapacity, it is not important which cooling rate is used, although the aluminum bronzes can also be cooled rapidly to lower temperatures. The preferred cooling method used is water cooling. However, the aluminum bronzes of the invention can also be quenched with oil or cooled in a circulating air stream.

The annealing makes the main part of the invention Aluminum bronzes converted into the ß.-phase. When cooling down quickly a high proportion of ß-phase remains, and this Phase undergoes a transformation called "martensitic transformation" known structural transformation, which is verbimden with a significant increase in strength and thus a Aluminum bronze provides an excellent combination of strength and ductility on v / e. The above described, annealing and rapid cooling method is hereinafter referred to as "β-phase generation". The one in the Macrostructure of the aluminum bronzes according to the invention Dispersion inhibits grain growth during ß-phase generation and thus contributes to a finer final grain size.

Even more significant improvements can be achieved if one the aluminum bronzes were swapped out after the ß-phase generation. This achieves an even greater increase in pestilence, in particular regarding the yield point. To carry out the warming out, hold the aluminum bronzes for at least 5 minutes.

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at temperatures of about 260 to 482 ° C., preferably from 315 to 40O ⁰ O. The strength can be further improved by cold rolling before or after aging. It is assumed that the increase in strength achieved by artificial aging is due to hardening effects caused by precipitation, which superimpose the normal effects of thermal aging.

By the aforementioned ß-phase generation and, if necessary subsequently carried out whiplash is the inventive Aluminum bronzes have a tensile strength of about 34 to about 126 kgf and a yield strength of about 52.5

awarded to about 105 kp / mrn.

According to one application form of the aluminum bronzes according to the invention becomes the excellent "deformability" of these Sheets made from alloys are used to process these sheets into molded parts. The forint will then rush through Giving high strength to annealing. According to this processing method can in particular e.g. membranes oüer Bourdon springs getting produced.

According to a further application form, the annealed or cold-rolled sheets from the aluminum bronze according to the invention]! processed into the desired molded parts, and these A-ground then united to larger parts, e.g. by brazing at temperatures of around 760 to 927 ° O. Included a high proportion of yes-phase is automatically generated in the part, and if the part is then quickly quenched,

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I U -

According to the aforementioned conferred high strength. By the presence; one of the aforementioned Dispersion in the alumirum bronzes of the invention also the favorable Wirlamgen described above achieved.

Another new method of processing the Altuniniurabronzen according to the invention described, in 'whose When these alloys are used, they have a particularly high ductility or ductility with increased teraperatureη ("SuOerplasticity") »

is awarded. In this procedure, use is made of the above-described V. ^r arr.i ~ or Kaltv / alz- and Glowt ufon under amU-r ^ m.

The invention thus also relates to a method for processing of the aforementioned aluminum bronzes, which is characterized is that you can get the aluminum bronzes

A) (a) at temperatures from about 538 to 760 ^J 0 warmverfο with and / or

(b) cold worked and optionally at least 2 minutes glows at temperatures of about 538 to 760 C and

B). superplastic at temperatures of around 704 to 927 C. deformed and possibly

G) cools rapidly to at least about 538 G and possibly

D) at least 5 minutes at temperatures from about 260 to about 482 ^° C., preferably from about 315 "to

ο
371 C, v / arm exposed.

The hot and cold forming or rolling as well as the annealing can in the method according to the invention in that described above

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Way to be carried out. It does not matter how long the glow is carried out at level (b), unless it is exceptionally strong. KornwKchstum takes place. Preferably, however , each individual glow stage is blooming for a maximum of about 2 hours.

UaG cold forming and annealing according to stage (b) is used to give the sheet metal and aluminum bronze an optimally fine grain structure prior to processing, as well as the desired molded part according to stage B). It will generally have a grain size below about. 0.06'j mm, preferably about 0.0Oi 'to 0.02 mm yen. The alloy components cobalt and zirconium carrier], as mentioned, contribute to the formation of the required fine grain structure.

3'Js it is established that the metal sheets are made of aluminum bronzes in accordance with the method according to the invention before they are processed does not have to be thermoformed to the desired molded part, when the sheets are cold-formed or rolled. During cold deformation a multiple reduction in thickness of at least 10 percent is preferably carried out. The applied Reduction in thickness, in particular 40 to 90 percent, especially 50 to 90 percent.

of course, the aluminum bronzes processed according to the invention need not annealed to * 'after cold forming or rolling because they recrystallize during superplastic deformation (B) to form the required fine grain structure. .

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It is also noted that the aluminum bronze !! in the proceedings de ?. ¹ invention prior to the application of stage B) do not need to be cold-worked and annealed according to ("b)". You can remove the sheets from the. Aluminum bronzes prior to the application of the deformation stage B) also without intermediate cold deformation and annealing to achieve the required fine grain structure according to (a). The hot forming is preferably carried out several times up to a reduction in thickness of 20 percent.

The "in the processing of aluminum bronzes according to the invention The surprising superplasticity that can be achieved is apparently caused by the fact that the aluminum bronzes at the deformation temperatures according to stage B) one have relatively low grain sizes in combination with the aforementioned proportions of ao- or ß-phase * At these temperatures The proportion of the ß-phase can depend on the aluminum content of the respective aluminum bronze and the temperature 0 to almost 100 percent. Preferably, however, the proportion of the ß-phase in the aforementioned temperature range is 40 to 70 Pro-'zont, which corresponds to an aluminum content of about 9 to 10 percent. The aforementioned optimal ß -phase ariteil allows Use of a higher rate of strain in the temperature range of the deformation according to B) and is therefore of practical importance, as it e.g. accelerates the production of Molded parts guaranteed. It is believed that the aforementioned Superplasticity in this case, see indefinitely at the boundary surfaces of the grains, which is a

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Allow the grains to move easily past each other without coarsening the grain. If the alurainium bronzes have a proportion of β-pliase within the aforementioned range, an even higher plasticity is achieved. This is obviously due to the ease with which the ß-phase adapts to the deformation of the less plastic οι grains.

The quotient from the Speed of the tie rod head (cm / min.) Through the To understand the initial length of 5.08 cm, which is determined in the tensile test using the appropriate test specimen.

The deformation according to stage B) is preferably carried out with a DqIi-

- ~ 1

voltage geoohspeed of below about 3 min., in particular

from about 0.03 to about 0.5 minutes. If one special high elongation is to be achieved, is expedient

-1

a stretching rate of no more than about 0.5 min. is used.

After step B) "may be the obtained molding, as mentioned, according to üüufe C) to cool rapidly to below at least about 538 ⁰ O to a high proportion of beta-phase maintain. Thereafter, the sheets can optionally to increase

according to their tensile strength and in particular their yield strength

Tempera level D), where Dian, as mentioned, preferably /

Doors from about 315 "to etv / a 371 ⁰ C applies. Stage D) is carried out in particular for a maximum of 4 hours in order to achieve a

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- Avoid coarsening of the grain.

If the cooling takes place slowly, as with normal air cooling, the molded part can of course still be kept at t.oi temperatures. Glowing from about 593 to et v / a 9Ö2 ° C and then rapidly 'cool down baw. quenching and artificial aging $ as described above is written.

It should be noted, however, that a relatively high tensile strength can be achieved mid yield strength, if one carries out a normal, ψ or slow cooling without further Beh & ndlun & Slevel. A tensile strength of at least about 70 kp / mm 'and a yield point of at least about 28 kp / mm' can be achieved.

It is surprising that the aforementioned aluminum bronzes, their mechanical properties of alloys of this type so far could not be achieved, processed by the simple, expedient and versatile process according to the invention v / can ground, Finally it is established that in the event ^ of the aluminum bronze according to the invention]! to maintain the required Proportion of ß-phase on cooling compared to, for example, the alloys described in US Pat. No. 3,297,497 a less high quenching speed is required is.

The examples illustrate the invention.

example 1

Cast ingots measuring 4.44 x 4.44 x 11.43 cm are grounded

made from the aluminum bronzes listed in Table I. ^ ₃ 10 9 8 51/13 27

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Table 1

Aluiriiniumbr onze Aluminum, Cobalt, Zirconium, Manganese, Copper

<fo fo ^c / o <? ö <? ö

A 9.7 0.8 0.2 0.44 remainder

B 9.6 1.0 0.2 0.40 Break

C 10.0 1.0 0.2 0.31 remainder

) Cu + · small amounts of conventional impurities

The Gus.8 "ingots are then hot-rolled in the temperature range from about 70 / to about 871 ⁰ O. When the thickness is reduced from 4.44 to 0.89 cm, the diameter is reduced by about ^ to 10 ^c p »Diekenverfiinderungen are limited by the whale diameter.

According to Dom WarmwalEon, the sheets obtained are a

Ej.ne annealed hour at about 621 ⁰ G, and finally presented at the air geuin

/ b to achieve cold rollability.

During cold rolling, the thickness is reduced from 0.89 to 0.076 cm, whereby between the annealing processes (at 621 ⁰ G) thick ciiv changes of 40 percent each are made (Hiii, With this procedure, a grain size of 0, produced 01 mm. the sheets are subjected ochliesslich 1 hour at about 900 G ⁰ of the "ß-PhaBenerzeugung", after they have the characteristics shown in Table 11.

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Table II

Aluminum bronze 0.2 ^ tensile strength, breaking point 'kp / mra ^ elongation, kp / mm ² #

A 61.6. 102.9 3.0

B 63.0 104.3 2.0

C 56.7 98.7 2.0

Example 2

The sheets obtained according to Example 1 are artificially aged for 1 hour at 343.degree. C. after the "β-phase generation" and then air-cooled. After this treatment, they have the W on in. III indicated properties table ..

Table III

Aluminum bronze 0.2 ^ stretch tensile strength, elongation at break,

limit, kp / mm kp / mm ■ ⁽ , Ό

A 97.3 121.8 0.5

B - 98.0 121.8 1.0

C 102.9 119.0 0.5

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Example 3

The drawing shows the elongation properties of an aluminum bronze (9 »7 percent Al, 1 percent Co, 0.2 percent Zr, 0.5 percent Mn, balance copper and conventional impurities) that at different temperatures and a speed of the 'tie rod head of 2.54 cm / min and 15.24 cm / min, achieved became. It can be seen from the figure that the lower the rate of elongation, the higher the plasticity of the alloy is.

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Claims (1)

P a t e η t a ■ η s ρ r ü c h e . Aluiriiniumbronaon, characterized in that they are made up of 8 to 11.8 percent aluminum, too 0.5 to 4 percent cobalt, 0.05 to 2 percent off Zirconium, 0.1 to 2 percent from Ilang8.ii, the remainder copper and small amounts of common contaminants and a metallographic structure with a proportion of ß-phase of 5 to 100 percent, remainder o6-phase, as well as.eine uniformly fine grain size with a grain size below 0.065 mm. 2. aluminum bronzes according to claim 1, characterized in that that the proportion of the ß-phase 85 to 100 percent, preferably '40 to 70f. 3. Aruminium bronzes according to claim 1 or 2, characterized in that that they 9> 4 to 10.4 percent, preferably 9.8 to 10 percent aluminum, 0.8 to 1.5 percent cobalt, Contains 0.08 to 0.15 percent zirconium and 0.5 to 1 percent manganese. 4. aluminum bronzes according to claim 1 to 3, characterized in that that they have a grain size below 0.04 mm. 5. Aluminum bronzes according to claims 1 to 4, characterized in that they contain a separate, uniformly distributed phase rich in cobalt and zärkonium. 109851/1327 6. Procedure for processing the aluminum bronzes according to Claim 1 to 5, characterized in that the Aliuainium.hr on zen A) (a) at temperatures of about 538 to 76O ⁰ C warm- deformed and / or (b) cold-worked and optionally annealed for at least 2 minutes at temperatures of about 538 to 76O ^{0 G and} B) superijlaistic at temperatures of around 704 to 927 C. vorforint and if necessary C) cools rapidly to at least below about 538 ^° C. and optionally D) at least 5 Hinuten at temperatures of about 260 to about 432 ⁰ C, preferably from about 315 to about 371 ⁰ C, v / arnauslagert, 7. The method according to claim 6, characterized in that in step a) a Reduction of at least 20 percent and that the farm deformation is carried out in several! passes . 3. The method according to claim 6, characterized in that -the cold deformation and annealing in step b) is repeated at least once while the cold deformation is carried out up to a bending deformation of at least 10 ° A. 10 9 8 51/13 2 7 BAb 9. The method according to claim 6 or 8, characterized in that respectively
that in stage b) / highest ens et v / a glowing for 2 hours. 10. The method according to claim 6 to 9 »characterized in that that nan the superplastic deformation (B) at temperatures from about 760 to 871 C dux-ch leads. 11. The method according to claim 6 to 10, characterized in that in step (B) an expansion rate of below 3 "min., Preferably from 0.03" to 0.5 min. ", Is used. 1?. Process according to Claims 6 to 11, characterized in that in stage I)) the v / arm is exposed for a maximum of 4 hours 1098S1 / 1327 bad o _RlaiNAL