US3773502A

US3773502A - Aluminum-zinc-alloy

Info

Publication number: US3773502A
Application number: US00094175A
Authority: US
Inventors: G Horvath; H Mayer
Original assignee: Voestalpine AG
Current assignee: Voestalpine AG
Priority date: 1969-12-03
Filing date: 1970-12-01
Publication date: 1973-11-20
Anticipated expiration: 1990-11-20
Also published as: NO126032B; JPS512408B1; DE2058212A1; IL35776A; SE357004B; CH545854A; DK141374B; GB1328125A; CH547862A; NL7017608A; CH547863A; DK141374C; LU62141A1; YU33810B; BE759746A; YU292170A; FR2072592A5; AT294439B; IL35776A0

Abstract

The invention relates to an aluminum-zinc-alloy consisting of 50 to 75 % aluminum, 0.3 to 1.5 % manganese and, if desired, copper, nickel, silicium, lithium and chromium, remainder zinc. As compared to known alloys used for the production of bearings these new alloys are provided with an increased red hardness, high load sustaining capacity at sliding movement, lasting accuracy to gauge, high mechanical strength, adequate resistance to corrosion, essentially increased resistance to creeping, increased applicability as casting and kneading material, and may be hot shaped at high working speeds with temperatures of the range 275* to 450* C.

Description

United States Patent Horvath et al.

ALUMINUM-ZINC-ALLOY Inventors: Gilbert l-lorvath, Linz, Austria;

Hans-Peter Mayer, Altena/Westfalen, Germany Assignee: Vereinigte Osterrichische Eisen-und Stahlwerke Aktiengesellschait, Linz, Austria Filed: Dec. 1, 1970 Appl. No.: 94,175

Foreign Application Priority Data Dec. 3, 1969 Austria 11272 References Cited UNITED STATES PATENTS 7/1939 Igarashi et a1. 75/141 Nov. 20, 1973 Primary Examiner-Richard 0. Dean Att0meyBrumbaugh, Graves, Donohue & Raymond [5 7 ABSTRACT The invention relates to an aluminum-zinc-alloy consisting of 50 to 75 aluminum, 0.3 to 1.5 manganese and, if desired, copper, nickel, silicium, lithium and chromium, remainder zinc. As compared to known alloys used for the production of bearings these new alloys are provided with an increased red hardness, high load sustaining capacity at sliding movement, lasting accuracy to gauge, high mechanical strength, adequate resistance to corrosion, essentially increased resistance to creeping, increased applicability as casting and kneading material, and may be hot shaped at high working speeds with temperatures of the range 275 to 450 C.

4 Claims, No Drawings ALUMlNUM-ZINC-ALLOY The invention relates to an aluminum-zinc-alloy containing manganese and, if desired, further alloy elements such as copper, nickel, silicium, lithium and chromium.

Aluminum-zinc-alloys, consisting of aluminum and zinc in various contents, manganese and, if desired, further alloy elements, which are used as materials for slide bearings are already known.

The use of an alloy containing 38 to 75 aluminum, 0.1 to 5 copper, and, if desired, manganese, titanium, chromium and vanadium, which elements may entirely or partly replace the copper, remainder zinc, as bearing material has been described. In the British Pat. specification No. 769,484 an alloy with 43 aluminum, 57 zinc, 4 copper, 0.3 manganese and 0.3 to 3 silicium is described. Further, bearing alloys on aluminum-zinc-basis with a copper addition are known, as e.g. the alloy described in the U.S. Pat. Nos. 2,900,288 and 2,982,677, British Pat. specification No. 725,818 and Canadian Pat. specifications Nos. 550.461 and 601.992 containing 30 to 66 aluminum, and copper, the copper content amounting to from one sixth to one quarter of the aluminum content, remainder zinc.

Further it is known to subject aluminum-zincalloys containing 35 to 55 aluminum and 0 to copper, remainder zinc to a heat treatment at a temperature of from 80 to 280 C over a period of 3 to 48 hours in order to obtain adequate sliding properties and lasting accuracy to gauge. Until now a heat treatment at higher temperatures had been considered disadvantageous because upon cooling, after heating to 275 C, an eutectoid structure is formed, i.e. the aluminum-containing mixed crystals segregate as two kinds of mixed crystals, one of which is rich in aluminum and poor in zinc while the other is rich in zinc and poor in aluminum. This eutectoid separation goes hand in hand with a change in volume which, in turn, causes an embrittlement of the material. For the same reason these alloys cannot be hot shaped at a temperature above 275 or 280 C, respectively. As a rule, these known alloys only served for the production of castings.

Furthermore, the use of known alloys on aluminumzinc-basis is greatly restricted by the fact that already at relatively low working temperatures of e.g. 80 to 90 C they show a great decrease in hardness and thus become useless. Some of these alloys also have the disadvantageous property of creeping, i.e. they undergo lasting changes in shape already under a slight longterm stress.

The invention is aimed at avoiding the described disadvantages and difficulties by creating an alloy which unites the following properties: increased red hardness (that is, hardness at elevated temperatures) as compared to known bearing alloys on aluminum-zinc-basis, high load sustaining capacity at sliding movement, lasting accuracy to gauge, high mechanical strength, adequate resistance to corrosion, essentially increased resistance to creeping as compared to known aluminumzinc bearing alloys, increased applicability both as material for casting and kneading (re-shaping operations). Further, the alloy should be hot shapeable at high working speeds, similar as this is the case with bronzes.

The alloy according to the invention with which these aims are reached is an aluminum-zinc-alloy containing 50 to 75 preferably 55 to 65 aluminum, 0.3 to l .5 preferably 0.5 to 0.8 manganese, and, if desired,

2 copper, nickel, silicium, lithium and chromium, remainder zinc. This alloy differs from other known alloys having a comparably high aluminum content in that its manganese content is limited at a maximum of The effect of the manganese content in the aluminum-zinc-alloy is based on the high inclination of the aluminum-zinc solid solution to be oversaturated with manganese during the rapid solidification under normal production conditions (particularly chill casting). Owing to this capacity (of the aluminum-zinc solid solution) to be oversaturated, it is e.g. effected that the manganese remains in solution but only to a particular, low percentage which again depends on the content of other alloy elements and does not form hard aluminides.

An examination with a micro-probe proved the uniform distribution of manganese in the microstructure when it is present in amounts of up to 0.4 With higher contents the mentioned aluminides will separate at first in fine (not yet harmful) and with a manganese content of more than about 1.5 in a coarser form.

Specific effects of manganese are: increase of tensile strength, yield point, elongation, resistance to wear, red hardness and resistance to corrosion. The manganese addition within the limits according to the invention furnishes an alloy on aluminum-zinc-basis with properties which are otherwise not obtainable or only with essentially more expensive alloys. Owing to the high content of aluminum of the alloy according to the invention and the therefore only very small change in volume during the eutectic transformation of the aluminumzinc mixed crystal it is possible and advantageous to carry out heat treatments also above a temperature of 275 C without the occurrence of an embrittlement in the material.

The copper content of the alloy according to the invention may amount to up to 3 The nickel content of the alloy according to the invention may amount to up to 1 The silicium content of the alloy according to the invention may amount to up to 0.6

The lithium content of the alloy according to the invention may amount to up to 0.1

The chromium content of the alloy according to the invention may amount to up to 0.5

Thus, a preferred embodiment for producing shaped bodies from alloys of the described kind by hot shaping resides in that a shaping temperature of 275 to 450 C, preferably of 330 to 350 C, is applied. Owing to the higher temperature for hot shaping it is possible to work with an essentially higher shaping speed than may be employed with known alloys. Shaping may also be effected by extrusion, traction and rolling.

The shaped bodies may also be produced from the described alloys by casting and subsequent heat treatment, the heat treatment being carried out at a temperature of 290 to 380 C, preferably 330 to 350 C. The duration of the heat treatment may amount to several hours up to 48 hours.

The invention is illustrated by the following Examples.

EXAMPLE 1;

By melting aluminum, manganese and zinc, an alloy of the following composition is produced which is used for manufacturing a bearing bushing with an inner diameter of 30 mm and an outer diameter of 40 mm.

The alloy is composed of:

remainder Zn.

After annealing for 40 hours at 330 C and cooling at the air the mechanical data of the alloy are the follow- The bearing bushings ran for 2 hours under constant drop oil lubrication and then for 20 hours without lubrication against a shaft of natural hardness made of structural steel having a tensile strength of 60 kp/mm (DIN St 60); in two test series the peripheral velocity once amounted to 1.5 m/sec. and then 0.3 m/sec. at a specific load per surface unit of 22 kp/cm No impairment of the shaft was discernable.

EXAMPLE 2:

The composition of an alloy is the following:

remainder Zn.

After annealing for 40 hours at 330 C and air cooling the mechanical data of the alloy are the following:

tensile strength o-B 29.2 kp/mm yield point S 23.7 kp/mm elongation 05 8 hardness, Brinell number HB 109 kp/mm at 25 C hardness, hot Brinell number:

50 C 75 100 C 125 C 150 C (HB, kplmm 98 91 82 73 65 The following Examples show the influence of slight contents of Cu, Ni and Si on the mechanical properties of the alloys according to the invention.

EXAMPLE 3:

The composition of an alloy is the following:

remainder Zn.

tensile strength oB 30.6 kplmm yield point GS 24.3 kp/mm elongation 0'5 7 hardness, Brinell number [-18 1 12 kp/mm Example 4:

The composition of an alloy is the following:

remainder Zn.

After annealing for 10 hours at 330 C and air cooling the mechanical data of the alloy are the following:

tensile strength 08 40.2 kp/mm yield point as 33.4 kp/mm elongation 0'5 5 hardness, Brinell number HB 115 kp/mm EXAMPLE 5:

The composition of an alloy is the following:

remainder Zn. The mechanical data of the alloy in the as-cast condition are the following:

tensile strength 08 33.7 kp/mm yield point as 26.5 kplmm elongation 05 4 bending fatigue strength: BW 9.5 kp/mm hardness, hot Brinell number:

25 C 50 C C C 125 C 150 C (HB, kp/mm):

107 98 85 79.5 65 When this alloy is subjected to a heat treatment at 300 C for 8 hours the mechanical data change as follows:

tensile strength 013 38.0 kp/mmE yield point 0'S 32.0 kp/mm elongation (r5 8 When the alloy is shaped as kneading material at 340 C the mechanical data are as follows:

tensile strength o-B 46.0 kp/mm yield point o-S 39.2 kp/mm,

elongation 05 14 bending fatigue strength: BW 11.5 kp/mm hardness, hot Brinell number: 7

25 C 50 C 75 C 100 C C C (HB, kp/mm EXAMPLE 6:

The composition of an alloy is the following:

55 A1, 0.3 Cu,

remainder Zn.

The mechanical data of the alloy in the as-cast condition are the following:

tensile strength 08 37.1 kp/mm",

yield point 08 33.1 kp/mm,

I elongation 05 4 hardness, Brinell number HB ll 1 kp/mm EXAMPLE 7:

The composition of an alloy is the following:

remainder Zn. After annealing for 8 hours at 330 C and air cooling the mechanical data of the alloy are the following:

tensile strength a8 37.3 kp/mm,

yield point GS 30.5 kp/mm,

elongation 05 2.7

hardness, Brinell number HB 115 kp/mm As is readily apparent from the above data, also the wherein the aluminum content amounts to from 55 to 3. The aluminum-zinc-alloy set forth in claim 1,

wherein the manganese content amounts to from 0.5 to

4. An aluminum-zinc-alloy consisting essentially of 50 to aluminum,

0.3 to 1.5 manganese,

0 to 3 copper,

0 to l nickel,

0 to 0.6 silicon,

0 to 0.1 lithium,

0 to 0.5 chromium,

balance zinc.

I v UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,775,502 Dated November 20, 1975 Inven fl Horvath, et al.

It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

First page, Item ['75:], "Osterrichisohe Eisen-und" should be --Osterreichische Eisenund-. Col. 1, line 19, "Pat." should read --Pats.-. Col. 5, lines 2A and 25, the hardness indications should appear beneath the temperatures to which they correspond, as follows:

I v 50C 75C 100 c lC 150C C01. 5, lines 51 and 52, the hardness indications should appear beneath the temperatures to which they correspond, as. follows:

(HE, kp/mm C 75 100 c 125C 150 c p/ 98 91 82 75- 5 Col. b, I line 52. "remainder Zn." should be indented on the line below "0 .3 N11,"; line should not be indented. Col. LI, lines #2, +5 and A, the hardness indications should appear beneath the temperatures to which they correspond, as follows:

, 25 0' 50 c 0 0 c c (HlB, kp/mm a 120 107 98 85 79.5 65

Column LI, line 51,- "elongation c 5 8%" should be indented, and

"when the alloy should be brought over to the margin; line 55, "follows: should be brought over to the margin; lines 62, 65 and 6A, the hardness indications should appear beneath the temperatures to which they correspond, as follows:

OHM PC4050 uscoMM-oc 60376-P69 9 U.S. GOVERNMENT fIUNTING OFFICE II! O3-33l.

U TEDsTATEs PATENTOFFICE f 1 CERTIFICATE OF CORRECTION Patent No. 5,775,502 'Dated November 20, 1973 lnvent fl Horvath. et el.

' C C C c C c (HB, kp/mm v 116 108 99 89 76 65 C01. 5, line 25, ["f'emainder Zn." should be indented, and "After annealing "should be brought over to the margin.

Signed and sealed this 16th day of July 197A.

(SEAL) V Attest: I

MCCOY M. GIBSON, JR. 0. MARSHALL DANN Attesting Officer Commissioner of Patents USCOMM-DC 60376-P69 FORM PO-1050 (10-69) v w as, covznnusm' ram-mac orrlc: IS! o-au-au.

Claims

2. The aluminum-zinc-alloy set forth in claim 1, wherein the aluminum content amounts to from 55 to 65 %.
3. The aluminum-zinc-alloy set forth in claim 1, wherein the manganese content amounts to from 0.5 to 0.8 %.
4. An aluminum-zinc-alloy consisting essentially of 50 to 75 % aluminum, 0.3 to 1.5 % manganese, 0 to 3 % copper, 0 to 1 % nickel, 0 to 0.6 % silicon, 0 to 0.1 % lithium, 0 to 0.5 % chromium, balance zinc.