Патент USA US2379434код для вставки
Patented 1.1, a, 1945 ' v _' . “ 2,379,434. UNITED STATES PATENT lorries Franskllensehlnlialapolk, man-user to we a P. I; Mall." l (10., 130-, litilllnlpolb, Incl, a corporation of Delaware _-" ~\ No , Application December 20, 1941, Serial No. 428,101 ' ‘ 0 Claims. (01. see-m) will have the highest strength-and are especially This invention relates to bearings. An object of the present invention is to improve ‘ useful where the bearing is not provided with a steelbsokingshell. Buchallmmbeproduced copper base" bearings. Other objects of the-invention will be apparent by ?rst melting the copper, then adding the thal iiuin to the melt. In some cases a small propor ' from the following description taken in connec tlonofother ingredientswillalsobeusedtoim~ tion with the appended claims. prove the properties of the alloy either during The present invention comprises the combina . melting or during. use. In any event. the melt tion of elements. and the product thereof brought should be thoroughly stirred before pouring. The out and exempli?ed in the disclosure hereinafter slloycan be used in'the formlof castings or in set forth, the scope of the-invention being indi 10‘ somecasesthecastmaterialmaybeforgedtothe cated in the appended claims. _ desired form. Photomicrographs of the material While a preferred embodiment of the invention show relatively small globules of thallium uni is described herein, it is contemplated that'con formly distributed throughout the casting at the siderable variation may be made in the method grainboundariesofthecoppermatrix. ’ of procedure and the combination of elements Bearings having this lower thallium content without departing from the spirit of the inven have su?lcient strength to withstand fairly heavy tion. loadswithoutsteelbackingsandmay alsobesub In the prior art, bearings have been formed of lected to impact loads when used with or without steel > copper or bronze containing various percentages of lead. While such bearings have performed with considerable satisfaction and have relatively high strength combined with low friction quali ties, such bearings have not always been satis factory in‘all-j particulars. For example, it has been di?icult to ‘obtain uniform distribution. of lead throughout'the copper matrix and this has Another class of copper-thallium bearings com- ' prises the group having the composition: Per cent Thalllum '- resulted in some non-unifo'mity of bearing prop-‘ erties. 10 to 20 oeppearahnlhi. Substantially the balance sinneesrmrsaren'efejrsblrmvmedwimstea haoklngshells to which the! may be integrally - attachedby fusion welding. casting, centrifugally Bearings of the type described are frequently bonded to a steel backing for additional strength 30 esstinmbra?nscr-cthsrmesns. sincethese com and support. Such bonding requires the appli cation of relatively high temperatures‘for a com paratively long period of time. Such prolonged m suneapplies'tiths ' , heating, however, interferes with the proper dis tributlon of leadand promotes the accumulationv 85 of thallium of the lead in relatively large globules. Such large size lead inclusionsare not as effective in promot ingabearing ofuniformlylowfrictionas areuni percentages as; Percent , _ .i 30%” Copper........... _- substan?allythehalanoe formly distributed ?ne particles ' of lead. Lead is also subject to‘ a certain‘ amount of oil; 40 corrosion when used in bearings. - The present invention contemplates a copper “Mormons-mausoleum orlkbiueselmotcrsandmayor'maynotihesteei 'I‘hebearingsofthepresent'invantime'anhe bac ‘ "base bearing of improved characteristics. Accord- - . ' made by several manufaetm'ing as ing to the present invention, the bearing‘ is formed ' of a copper base metal composition containing - by the melting. mixing-and scribedabove. Theycanalsohaymadebysimul thallium instead of lead. It is contemplated that ’ the bearing may be formed of metal compositions taneously electroplating I within the following fame of proportions: It'is Percent Thallium arose ins themixture'. The proportion of thallium used will be varied of the is required‘to be subiected. The lower'per 65. ‘recreation In casting, a ‘Ilium ~ ~ ' thismethodissmtable forv the entire composition rangedisclosedlit is par- , ticularly advantageous percentages .' ,oi' thallium are is‘easier to prevent dependingupontheservieetowhichthebearing Copper---_..-.. ..... - _ bymi'iingthemetalpowders, mmdlll'im _ Copper.... -_'. ..... .. Substantially the balance centagesof thallium such as:_ thallium from a suitable... ‘taking vplaice. I, of thallium segre-t gaticn may thorough misinggis achievedfollowed by afairlyrapid cooling. another methodof manufacture comprises " ‘£010 the balance so spraying mixed molten partielssof copper-and.‘ I . - I ' 2 2,379,434 thallium onto the surface to ‘be provided with a bearing using either a Schoop gun wherein the - I Percent (2) Thallium --_-___; _________________ .._ 22.42 raw materials are used in the form of wire, or 'a Shori gun wherein metal powders are used. ‘It is of advantage in some cases to improve the 5 -characteristics 01' the copper by the addition of relatively small quantities oi materials which act Balance In order to still further improve the corrosion _ resistance of the alloy it has been found of ad~ ‘I vantage in some cases to apply a coating of in-' either as grain re?ners or hardening ingredients or both. One of the most useful materials is tin ‘. dium preferably by electroplating the surface of which may be present in proportions varying from 10 the ?nished bearing and then heat treating the .1 to 10% by weight of the composition. The tin bearing ‘to di?use the indium into the surface. increases the hardness and strength of the cop Indium and thallium form a series of solid solu per base and increases the resistance of the bear tions which are highly corrosion resistant. The ing to fatigue. indium plating can be di?used into the thallium Instead of tin, silver may also be used to in at slightly elevated temperatures such as 300° F. In some cases the indium can be added di-. crease the strength of the copper base and it does so without greatly decreasing the thermal con-' rectly to the copper~thallium alloy prior to cast ductivity of the‘ bearing. Silver also appears to ing. One such bearing alloy which was found to‘ provide a nucleus-forming ingredient which pro show a very pronounced segregation of thallium motes ‘the ?ne and homogeneous distribution-of so globules in the grain boundaries had the-composi the free thallium phase. Nickel and manganese also act as grain re?ners and improve the physi-. . Per cent tion: cal properties of the bearing. 1 . r p ‘ ' ' Thallium and copper do not form solid solu 4.78 Indium _ tions and hence the thallium is distributed in the bearing in the form of small particles interspersed .45 Copper with the grains of the copper matrix. These small . thallium particles or globules are very ductile and ' Balance It may also be of advantage in preparing the , bearing alloy to add small amounts of alkali or v‘alkaline earth metals as deoxidizers. These me soft. Moreover. cold working, such as is always - 1 also eiiect grain re?nementand may increase present at a bearing surface, ‘does not harden the 80 the" hardness of the thallium somewhat. thallium particles. It is believed that this is one ‘application is'a continuation-in-part of factor which renders copper-thallium composi myco-pending application for Bearings, serial. tions so well suited for bearing purposes. No. ssasoamed September 16. 1938. since the thallium particles will melt at-a tem perature of approximately 578'’ 1''. they will a?ord 3,5 ' While the present invention, as to its objects and advantages. has been described herein as car liquid lubrication if the oil supply should be tem porarily cut off and the bearings become over- > ried out in speci?c embodiments thereof,v it is not desired to be limited thereby but it is intended to heated. . . cover the invention broadly within the spirit and The hardness or the copper-thallium alloys at ' room temperature and at elevated temperaturesv 40 scope of the appended claims. > ‘What is claimedis: is low. For instance, a bearing of: ‘ .1. A’ hearing formed‘of a. metal composition of Per cent ’ .2‘to 35% thallium'and‘ the balance substantially 'Ihallium - 20 ~ all copper. Copper _ Balance . 2. A hearing formed of a metal composition of had a Brinell hardness of 36 at 80‘? F. and the 45 s to 10% thallium and‘ the balance substantially - hardness was reduced to 27 at 355° F. The bear7 ‘all copper. ing was found to have excellent anti-friction 1 3. A bearing formed of a metal composition of. characteristics. 10 to 20% thallium and the balance substantially ~ ' Another bearing formed of: all copper. Per cent 10 Thallium Copper Balance was also found to have high anti-friction char acteristics. Alloys of the following compositions, when melted, thoroughly stirred and chill cast showed a uniform ?ne dispersion of the thallium at the rain boundariesof the copper matrix: ‘ Per cent (1) Thallillm -'._-...... ............ -s ____ __ 11.11' Tin ' I 2.87 Copper .._. .... _-..__._--_..-__-..._ 3.181106 60 ’ 4. A bearing formed of a metal composition of 20 to 35% thallium and the balance substantially all copper. - 5. A copper base bearing formed of. a copper. base matrix and small particlessi'pf' thallium dis tributed in the bearing at the grain boundaries of the copper base matrix, said thallium forming 2 to 35% by weight of the bearing composition. 6. A copper base bearing formed of a copper base matrix and small particles of thallium dis 00 tributed in the'bearing in the found small par ticles interspersed with the grains ‘of the copper matrix, said thallium forming 2 to 35% by weight of the bearing composition, . ' ' FRANZ R. HENSEL. v '