US2121204A - Bearing metal alloy - Google Patents

Description

Pasta time at, 1938 artiste all Edward! P. Lans'worthy, Rochester, N. K, assignor to Ecariiim Metals 'Corporation Rochester, M. iii, a coration at New Yon-la No Drawing.

Application Novenaher lit, i936,

estalt No. lllhtlill l filaiml This invention relates to an antiiriction metal,

proposing an alloy suitable for suhstantiallv universal application as a hearing metal and having components which will readily unite in such pro 5 portions as may be most suitable for each particular use.

Heretofore, tin has been considered as one oi the essential components of alloys of the, char-'- acter generally described, When'emplovecl in it) relatively small quantities, i. e. less than 1fl%,

this metal will, if other factors (which are variable and olimcult of control) are favorable, unite with the other components to form a solid solu-'- tion. However, if a percentage of tin greater than the order of 10% be employed, the tin will he thrown out of solution as the mixture cools and will unite with one of the components to form a substance 'whlchin many respects is similar to 'a eutectold alloy; For example, when copper is 20 one of the components the excess tin combines .with it, the substance thus produced heme so much harderthan the matrix metal that it is unsuitable for the purpose in view. The mealmum percentage of tin which can he employed without the formation oi sucha substance is variable, depending, anions other factors, upon the elements which form the alloy, the temperature at which the molten metal is poured and the rate at which it is permitted to cool. The per- 30 centaae of tin necessary to impart the olesired properties to the alloy may he, however, and in many instances is, substantially areatee than ttiotwhich will remain in solution. in such cases.

oi course, a lower percentage oi tin than is cle 35 sirahie must be employed. Un the other hand, the percentage of tin requireol may he within a tense in which it is impossible, without performins tests, to detene whether all oi it will re main in solution. Tin, therefore, is satisfactory to only when the proportion which is necesisarp in impart the tiesirecl. properties to the alloy is less than that at, or shove, which the tin will he thrown out of solution.

The principal object oi the invention is to over- 45 come the above objections, this ohiect content plating an alloy of the character generally olescribed which :loes not involve the use of tin and wherein each component will reaoiip term a union with the remaining components through 50 out the entire range of proportions which may he necessary to modify the cacterlsitic properties of the alloy in new]: with the particular environment under which it is to he employed.

it. further object is to proviile a. hep metal to whose comments, as to proportio, are c WE. is-ass) termlnecl in accordance with the physical characteristics of the parts which contact with, and which are movable relatively to, the said metal.

A still further object is to provide a hearing metal which will prevent excessive wearing or 5 scoring oi the shaft or other associated part in the event that there is a failure in the supply of the lubricating medium to the cooperating surfaces.

The invention contemplates a hearing metal consisting of copper, lead and nickel in the following proportions: copper from 45% to 77%; leaa from 20% to 35%; and nickel from 3% to The specific percentage selected in each of the 15- ranses noted is determined by the environment in which the metal is to he used, it being preterreo that the hearing metal in each case be slightly softer than the metal of the shaft or other part which is to be associated with it in order that if the friction between the parts hecomes excessive, owing to a failure in the supply or theluhricatine medium to the cooperating surfaces, or for any other reason, the hearing metal will take up the increased wear, thereby preventinc illgawy to the said shaft or other part. lfhe alloy is rendered softer by increasing the percentage of lead or lay decreasing the percentage of nickel, or both, and is rendered. harder by decreasing the percentage of lead or increasing the percentage of nickel, or both. assuming, for en:- ample, that the alloy which is to he produced is to he formed into hearings for shaits of relatively soft eteeLthe percentage of lead which is selecteol will he near the upper limit of the range indi sated. The percentage oi nickel, although relatively low, will he as high as is permissible, the greater part oi the desired degree of softness preferably helm; attained, when this is possible, by the use oi a high percentage of leati rather to than by a low percentage of niche in order that the adhesive characteristic of the copper will he 7 counteracted while the antifrictional properties of the alloy will he substantially increased. a v relatively high percentage oi nickel has the ad to vantase that the compression and tensile strength of the alloy are correspondingly high. On the other ha'ncl, if the alloy which is to be produced is to he formeol into hearings for shafts of relatively hard steel the percentages oi the alloy comso ponents are selected so that the metal of the hearinns will be relatively hard, although slightly softer than that of said shafts, it being preferred that, it possible, the greater part oi. the increase in hardness oi the alloy be attained; in such case so by increasing the nickel content rather than be decreasing the lead content in order to retain in as large a degree as possible the high anti-frictional properties inherent in the lead.

It will be apparent from the foregoing that the invention contemplates a bearing metal having components which may be used in such proportions as will insure an alloy which will be relatively softer than the shaft or other part with which it is to be employed. It is preferred, however, that in each case the bearing metal be only slightly softer than such shaft or other part, the proportions of the alloy components being selected so that the softness, or hardness, of the bearing metal is correlated to that of the said shaft or other part. As each component of the bearing metal described will readily unite with the others in amounts which will enable the attainment of this end, maximum compression and tensile strength and high antifrictional properties are insured for each environment of use,

The bearing metal has the further advantage that scoring or marring of the shaft or other associated part will be prevented even though there may be a failure in the supply of the medium which is utilized to lubricate the cooperating surfaces. If for this reason, or for any other reason,

the friction between the cooperating surfaces becomes excessive the only surfaces scored or marred, if any are scored or marred, will be those provided by the bearing metal.

The alloy may be produced in any suitable maner. The preferred practice is to heat in a crucible, or otherwise, ingots having a copper content of and a nickel content of 50% together with copper which is added in an amount which will bring the total copper content of the mixture up to the desired percentage. After the ingots and added copper have melted they form a solution, the copper being the solvent and the nickel the solute. The lead, preferably molten and substantially pure, is then introduced into the crucible, it being understood that the lead may, if desired, be introduced in a solid state. The lead is not in solution but is in suspension, the particles thereof being uniformly dispersed throughout the molten solution and being assisted incidentally by the nickel in maintaining their positions in the solution.

I claim as my invention: Y

An alloy for providing a bearing which is capable of preventing excessive wearing or scoring of the shaft or other associated part in the absence of a lubricating medium, said alloy containing 45% to 77% copper, 20% to 35% lead and 3% to 15% nickel, the sum of the percentages of copper, ieadgand nickel equaling substantially EDWARD P. LANGWORTHY.