DE1224936B - Use of an iridium alloy to make springs - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. Cl .:

C22c

German class: 40 b-5/00

Number: 1224 936

File number: J 24693 VI a / 40 b

Filing date: November 7, 1963

Opening day: September 15, 1966

From the commemorative publication "100 Years of Heraeus Hanau", 1951, pp. 137 to 141, there are iridium-tungsten alloys known with tungsten contents of up to 95%. Furthermore it is according to the German patent specification 823 521 known, iridium-tungsten alloys with 55 to 85% iridium, remainder tungsten, because of their Hardness and chemical resistance as a material for nib nibs and gramophone needles use.

The invention is based on the knowledge that certain iridium-tungsten alloys have properties have that they are particularly suitable as a material for the production of springs do. One of the important spring properties is the lowest possible relaxation value (elastic Fatigue). If a spring returns to its original position as a result of relief, then you are Relaxation value equal to zero. However, if the spring does not return to its starting position after the but if it occupies some intermediate position, then the relevant extent becomes their deflection, elongation or compression as a percentage of the deflection, elongation or compression under load. However, the relaxation value increases with it The temperature increases rapidly and increases over time even when exposed to high temperatures.

For at elevated temperatures of about 300 to 500 ⁰ C to be used springs, certain nickel-cobalt-chromium alloys have proved, however, exceeding at 500 ° C temperatures do not have satisfactory relaxation value more.

According to the invention it is therefore proposed as a material for producing springs that are in use Exposed to temperatures of 500 ° C and more, an iridium alloy made of 0.5 to 7% tungsten, Remaining iridium to be used. Have the alloys falling within the above-mentioned content limits a significantly lower relaxation value compared to the known alloys.

With a view to the lowest possible stress relief value, the alloy must contain at least 0.5% tungsten, but the tungsten content is preferably at least 2%. For springs to be used at 700 ° C and above, the alloy preferably contains at least 3% tungsten, since alloys with only 2% tungsten easily recrystallize and lose their resistance to elastic fatigue at 700 ° C. If the tungsten content of the alloy to be used according to the invention exceeds 7%> then it becomes difficult or even impossible to shape the alloys into springs. From using an iridium alloy for
Manufacture of springs

Applicant:

International Nickel Limited, London

Representative:

Dr.-Ing. G. Eichenberg

and Dipl.-Ing. H. Sauerland, patent attorneys,

Düsseldorf, Cecilienallee 76

Named as inventor:

Edward George Price, London;

Laszlo Dezso Romhanyi,

Kingston upon Thames, Surrey (Great Britain)

Claimed priority:

Great Britain 8 November 1962 (42 273)

For positional reasons, the tungsten content of the alloys should therefore not exceed 6%.

Iridium usually contains small amounts of other precious metals such as gold, platinum, palladium, Ruthenium, rhodium, silver and osmium, a maximum of 0.2% in total · These elements come therefore only present as an impurity in the alloys to be used according to the invention. tungsten also contains up to 0.1% molybdenum, copper and nickel as impurities.

The main advantage exhibited by the springs made according to the invention arises from a comparison with the springs made of an alloy previously used at higher temperatures made of 18% cobalt, 20% chromium, 2% aluminum, 3% titanium and 57% nickel. The moduli of elasticity of the springs can be found in the table below:

Number table I

alloy

18% Co, 20% Cr, 2% Al, 3% Ti,

57% Ni

Ir + 0.5% tungsten

Ir + 2% tungsten

Ir + 5% tungsten

modulus of elasticity
10 ° kg / cm ²

2.46
5.32
5.52
5.38

609 660/340

The following values were obtained as percentage relaxation values at a maximum load of 14.06 kg / mm ² in 100 hours at various temperatures:

Number table II

187o Co, 207ο Cr ₃
27ο Al, 3 7ο Ti,
577ο Ni

Ir + 0.57ο W ....

Ir + 27ο W

Ir + 57ο W

400 ° C 500 ° C 600 ° C 700 ° C 800 ⁰ C

1.8
13.9

7.7
13.1

14.2

16.4

10.4

6.9

24.4

17.8

17.5

8.5

70

23 13

100

25 can be connected to a conductor part. Other hand, nickel-cobalt-chromium alloys form at temperatures above 300 ⁰ C oxides that interfere with good electrical contact. Such oxides do not arise with the alloys to be used according to the invention.

When producing the springs according to the invention, one can start from a powder mixture consisting of iridium and tungsten, from which small blocks are melted under an argon arc, which are then thermoformed into strips or wire. The springs can apply as a leaf or as a strip which preferably at 650 to 700 ⁰ C is wound.

15th

From the table of figures it can be seen that the springs, which are made of a nickel alloy, have a temperature up to 400 ° C have a very low relaxation value, which is lost at temperatures above 500 ° C. While at 800 ° C the elastic fatigue of the known ao nickel alloy is 100 7o, the iridium alloy possesses with 57o tungsten with the same load Another relaxation value of 25 7o · Another The advantage of the alloys to be used according to the invention results from the fact that they provide good electrical properties Irish contacts can be easily made. In electrical engineering, the Feathers not only requires that they work properly at high temperatures, but that they also have one Have good electrical conductivity and feel good

Claims (2)

Patent claims: 1. using an iridium alloy,
consisting of 0.5 to 77o> in particular 2 to 77o tungsten, the remainder being iridium as a material for producing springs that are exposed to temperatures of 500 ° C and more during use. 2. Use of an alloy of the composition mentioned in claim 1, the 3 to Contains 67o tungsten for the purpose of claim 1. Considered publications:
German Patent No. 823521;
"100 Years of Heraeus Hanau" (Festschrift), 1951, pp. 137 to 141. 609 660/340 9.66 © Bundesdruckerei Berlin