US1691931A - Bearing-metal alloy - Google Patents

Description

Patented Nov. 20, 1928.

UNITED STATES KARL MULLER AND WILHELM SANDER, F ESSEN, GERMANY:

BEARING-.METAL ALLoY.

No Drawing Application filed September 30 1921,

of lead, percent of antimony and 5 percent.

of tin. For the purpose of avoiding segregation as well as increasing the degree of hardness, small percentages of copper have been added to these lead alloys. However the alloys of this type did notshow such properties as to render them capable of being employed as full substitutes for the former bearing metals containing percent and more of tin.

Thereafter it has been tried to develop the scribed above are by no means lessened, but

desired properties in the alloys mentioned by adding other metals, but owing to the fact that most of the metals will not alloy with lead, these experiments failed because in some cases it was impossible to get a perfect mixing or, in other cases, on cooling the additional metals separated out from the alloy. Moreover if one succeeds in introducing small amounts of other metals without risk of separation on cooling, the further'disadvantage arises that these additions will solidfy at temperatures above the eutectic of lead, antimony and tin, in such a way that the alloys must pass through a rather large range of solidification and consequently become pasty on cooling. This fact involves a very high casting temperature whereby oxidation will be advanced, the easily oxidizable constituents will be burned off, and the tendency to segregation will be increased. Besides, when casting such bearing metals, frequently piping and blisters are formed owing to the large melting range.

We have found that all the objections pointed out above can be avoided, and that it is possible to obtain in such alloys with a high lead content, though containing only a small (say 4 to 5 percent) amount of tin, all those properties to make them fully equivalent substitutes for the high-grade tin alloys formerly used for bearing metals.

This surprising effect is essentially realized by relatively small (say 1 to 3 percent) additions of nickel together with a somewhat smaller quantity of copper. Preferably the copper is introduced in the shape of copper phosphide, the phosphorus in this combina Serial No. 504,374, and in Germany October 1, 1920f tion increasing the hardness of the alloy to a certain extent. The phosphorus may in this case be Wholly or partially replaced by arsenic which is known to be equivalent to phosphorus with respect to the metallurgical action under consideration.

Based on numerous elaborate experiments, the following limits can-be stated for the constituents of alloys which will show the advantages mentioned abovei about 70 to 75 percent of lead, about 15 to 25 percent of antimony, about 3 to 6 percent of tin, about 1 to 3 percent of nickel, about 0.6 to 1.5 percent of copper (introduced in form of 0.8 to 2.2 percent of copper phosphide) The many advantages of such alloys as deeven in some respects are increased by wholly or partially substituting cobalt for nickel. Nickel and cobalt are metals of the same type, closely resembling each other but for the present purposes cobalt has some specific advantages. Such an alloy containing cobalt specially difiers from the corresponding nickelalloy, inasmuch as it possesses a higher degree of plasticity and, consequently, a greater hardening capacity without risk of becoming too brittle.

Finally we have found that such alloys as described above, i. e. with a very high lead content and a lower content of antimony and tin, which are improved by small additions of nickel, or cobalt, together with copper, will be improved further by introducing relatively very small quantities ofmetals belonging to the iron or chromium-group, preferably conjointly with elements of the phosphorusgroup.

By way of example for such an alloy the following composition may be stated: .70 percent of lead, 20 percent of antimony, 5 percent of tin, 2 percent of nickel, 1 percent of copper, 0.7 percent of iron, 0.3 percent of manganese, 0.5 percent of phosphorus, 0.5 percent of arsemo.

1. A bearing metal alloy comprising about This bearing metal alloy by reason of its 7 O to 75 percent of lead, about 15 to 25 percent )f antimony, about 3 to 6 percent of tin, about 1 to 3 percent of a'metal of the cobalt type,

1 to 3 percent of cobalt, and about 0.6 to 2 I percent of copper.

3. A bearing metal alloy comprising about 70 to 75 percent of lead, about 15 to 25 percent of antimony, about 3 to 6 percent of tin, about 1 to 3 percent of nickel and cobalt together, and about 0.6 to 2 percent of copper.

4. A bearing metal alloy comprising about 70 to 75 percent of lead, about 15 to 25'percent of antimony, about 3 to 6 rcent of tin, about 1 to 3 percent of metal of ti: cobalt type, about 0.6 to 2 percent of copper and an a preciable amount not exceeding 1 percent of e e'rne'nts of the phosphorus group.

1 to 3 percent of cobalt, a

5. A bearing metal alloy comprising about 70 to 75 percent of lead, about 15 to 25 percent of antimony, about 3 to 6 percent of tin, about out 0.6 to 2 percent of copper, and an appreciable amount not exceeding 1 percent of elements of the phosphorus group. v

6. A bearing metal alloy comprising about 70 to 75 percent of lead, about 15 to 25 percent of antimony, about 3 to6 percent of tin, about 1 to 3 percent of a metal of, the cobalt type, about 0.6 to 2 percent of copper, an appreciable amount not exceeding 1 percent of metals of the iron group, and an appreciable amount not exceeding 1 percent of elements of the phosphorus group.

In testimony whereof we aflix our signatures.

' DR. KARL MULLER.

DR. WILHELM SANDER.