US3720507A - Copper-lead alloy - Google Patents

Copper-lead alloy Download PDF

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Publication number
US3720507A
US3720507A US00062338A US3720507DA US3720507A US 3720507 A US3720507 A US 3720507A US 00062338 A US00062338 A US 00062338A US 3720507D A US3720507D A US 3720507DA US 3720507 A US3720507 A US 3720507A
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United States
Prior art keywords
lead
copper
alloy
promoter
grams
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Expired - Lifetime
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US00062338A
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English (en)
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C Lundin
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Colorado Springs National Bank
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Colorado Springs National Bank
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    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C1/00—Making non-ferrous alloys
    • C22C1/02—Making non-ferrous alloys by melting
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C9/00—Alloys based on copper
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C9/00—Alloys based on copper
    • C22C9/02—Alloys based on copper with tin as the next major constituent
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C9/00—Alloys based on copper
    • C22C9/04—Alloys based on copper with zinc as the next major constituent
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C33/00—Parts of bearings; Special methods for making bearings or parts thereof
    • F16C33/02—Parts of sliding-contact bearings
    • F16C33/04—Brasses; Bushes; Linings
    • F16C33/06—Sliding surface mainly made of metal
    • F16C33/12—Structural composition; Use of special materials or surface treatments, e.g. for rust-proofing
    • F16C33/121—Use of special materials
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C2204/00—Metallic materials; Alloys
    • F16C2204/10—Alloys based on copper
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C2204/00—Metallic materials; Alloys
    • F16C2204/10—Alloys based on copper
    • F16C2204/16—Alloys based on copper with lead as the next major constituent
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S384/00—Bearings
    • Y10S384/90—Cooling or heating
    • Y10S384/912—Metallic

Definitions

  • Another problem associated with the use of copperlead alloys is that even if there is initial homogeneity, under high stress and temperature conditions, the lead has a tendency to separate and segregate from the copper.
  • a further problem associated with copper-lead alloys is that the lead tends to segregate from the copper when it is being remelted and recast into other shapes and forms.
  • Another object of the present invention is to provide a homogeneous copper-lead alloy in which segregation of lead from copper is reduced on remelting.
  • Yet another object of the present invention is to provide a homogeneous copper-lead alloy which is useful for production of bearings and a bearing material.
  • Yet another object of the present -invention is to provide a process for making the improved copper-lead alloy of the present invention.
  • the foregoing and other objects are accomplished by adding effective amounts of a homogeneity promoter to the molten metal.
  • the promoter comprises elemental carbon and a rare earth metal compound which reacts under the molten conditions present during the alloying and casting of the copper and lead.
  • the mechanism provided by the promoter apparently is one of inoculation of a line dispersion of the lead particles in a copper matrix. Examples of such compounds are the uorocarbonates, carbonates and oxides of the rare earths.
  • Copper-lead alloys are produced according to the present invention in varying proportions of copper and lead.
  • the proportions may be varied as desired and as the specifc application dictates. It has been found that alloys of substantial utility are those which contain 5% to 55% lead and to 45% copper. The problem of separation and segregation of the lead and copper is greatest with a high lead content.
  • the promoter of this invention therefore provides its greatest utility at lead contents of from 20 to 45%. If the lubricating qualities of the alloy are to be increased, the proportion of lead should be in the higher range. If it is desirable to increase the strength of the material, a lesser proportion of lead should be utilized.
  • the elemental carbon component is preferably nely powdered graphite.
  • co-arser carbon may be used, the larger particles tend to decrease the efficiency of the process, presumably due to reduced surface area to volume ratio.
  • Other forms of carbon include bone-black, carbon-black, charcoal and the like.
  • rare earths and rare earth carbonates as used throughout this application are intended to include scandium, yttrium, lanthanum, and the lanthanides, the latter term encompassing those metals having atomic numbers from 58 to 7l.
  • the preferred rare earths are cerium and yttrium and mixtures thereof with lanthanum, praseodymium, neodymium, samarium and europium.
  • the preferred rare earth compounds are the halocarbonates, particularly the uorocarbo-nates of the above metals.
  • the carbonates and oxides of the rare earths are also suitable in this invention.
  • an alkali or alkaline earth compound may be present in the homogeneity promoter.
  • 'Ihe alkali metal component compound may be lithium, potassium or sodium (or other metals of Group la of the Periodic Table), preferably combined'as a carbonate.
  • the alkaline earth compound may be calcium, strontium or barium (or other metal of Group lla of the Periodic Table) preferably combined as a carbonate.
  • the amount of homogeneity promoter used must be at least that amount which ensures formation of a uniformly dispersed mixture of lead and copper which does not segregate on solidification.
  • a preferred effective range of the proportions has been found to be about 1-5 grams of carbon or graphite powder and about 3-15 grams of rare earth compound for each pound of alloy. Below this proportion improvements in homogeneity are obtained, but the effect is less pronounced when a very minor amount of promoter is used. Higher amounts of the homogeneity promoter may be used, for example, up to 10 grams of graphite and 30 grams of the rare earth compo-und for each pound of alloy. Although these and even greater amounts provide an improved alloy in accordance with the present invention, the use of greater amounts from an economic standpoint is less attractive.
  • the maximum proportion of the promoter is determined by characteristic requirements of the alloy, and economic considerations.
  • the amount of alkali or alkaline earth method compound is from 0-30 grams per pound of alloy; but preferably from 2f-l5 grams.
  • the rare earth compound may be partially decomposed to liberate gases which provide a stirring action and nucleation effect and that the undecomposed portion of the promoter also provides nucleation sites.
  • the following reactions may occur:
  • CeFCO3 CeFO+ C02 The nucleation and possibly agitation prevent gross separation of the load and the copper phases.
  • the nucleation sites cause the final solidified structure to be fine-grained and further allows more efficient and homogeneous entrapment and entrainment of the lead phase in the copper matrix.
  • inoculation occurs by unreacted (or partially reacted) rare earth compound and graphite during stirring of the melt. The inoculation by these particles which are not fully decomposed provides sites for the nucleation and growth of fine lead particles.
  • the combined action promotes a random, fine-grained dispersion of lead in copper which is mandatory for the optimum characteristics and requirements of a bearing alloy. If desired, inert atmospheres may be used to blanket the system.
  • the process of this invention produces a novel copperlead alloy which has a finer and more uniform dispersion of the lead in the copper.
  • the composition of the alloy is from 5 to 55 percent lead, preferably 20 to 45 percent lead, 95 to 45 percent copper, preferably 80 to 55 percent copper, with up to percent of other metals, preferably zinc and/or tin, with only minor amounts of other metals, and trace amounts of the homogeneity promoter.
  • the preferred average particle size of the lead in the copper matrix is between 0.002 mm. to 0.020 mm. diameter. Larger particles of lead occur but only a very minor amount of segregation occurs, which is not detrimental.
  • An average particles size of 0.002 to 0.010 mm. for copper-lead alloys having to 45 percent lead produces an excellent alloy in accordance with the present invention. The average particle size remains approximately within the above ranges even after the alloy is remelted or recast, although some minor agglomeration does occur.
  • Another advantage of this process is the remelt capability of the copper-lead alloy without substantial segregation. This effect is desirable particularly if the material is produced as solid billets for use in subsequent castings into desired forms.
  • the remelt capability without undesirable segregation is believed attributed to remnants of the homogeneity promoter remaining in the alloy or may be a function of the iineness of the original dispersion.
  • the homogeneity promoter has a lingering effect in improving the homogeneity of the alloy it may be desirable upon successive remelts, or where the original alloy composition remains molten for an extended period of time, to add the homogeneity promoter in increments. For example, when the alloy remains molten for a period of 10 minutes to an hour, a second addition of the promoter in an amount within the preferred effective range should be made prior to using (i.e., casting) the alloy.
  • Additional additives may be used in combination with the above-described homogeneity promoter.
  • a metal phosphate such as ortho lead phosphate, ortho cupric phosphate or ortho tin phosphate.
  • copper of the desired quantity is placed in a graphite crucible and brought to a temperature of 1250"- l350 C. using an induction heater.
  • the lead and the homogeneity promoter are added to the melt preferably with stirring.
  • the temperature of the mixture is maintained for at least l minute and preferably 3 minutes for best results.
  • the melt is then allowed to cool through its solidification temperature.
  • the purity is high since the alloy has been thoroughly deoxidized.
  • the lead phase is finely and randomly dispersed throughout the copper matrix. Thes factors contribute to a low coefficient of friction in the lifetime of the bearing alloy. They also have a high thermal conductivity, and low electrical resistivity. In addition, they may be sintered, drawn, extruded, rolled and machined without losing their superior anti-friction qualities.
  • the alloy of the present invention is particularly useful as a bearing surface. It is suited for use when high or low temperatures and high stresses are present. Most strandard methods for making bearings and bearing sur faces may be employed.
  • the bearing can be made by castin-g techniques as set forth in greater detail below. Additionally, powder metallurgical techniques are useful.
  • the alloy in bonding the alloy of the present invention to steel, the alloy can be powdered utilizing an atomization method to as fine as 1 micron. The steel is heated, until it turns blue (approximately 600 F.) and the powder made from the alloy is then sprayed onto the steel surface. The heat from the surface of the steel bonds the copper-lead alloy to the steel on contact.
  • the powdered alloy can also be sintered onto a steel backing to provide a thicker bearing surface. The bond is strong enough to resist high stresses that result from bearing forces while providing excellent bearing properties.
  • the alloy of the present invention can be used as an additive to lubricants.
  • the alloy is combined in powdered form with other lubricants such as greases and oils in quantities ranging preferably from a trace to 4 ounces per pound of the grease or oil.
  • the resulting combination is a lubricant which fully coats moving parts thereby increasing the life of these parts. Maintenance requirements are also reduced.
  • the alloy is of value when the lubricant combination is used in sealed units where frequent changes of lubricant are uneconomical. In this application, the improved results are obtained over a longer period of time when higher percentages of lead are used in the alloy.
  • the alloys of the present invention may also be of value in ordnance developments, such as for small arms ammunition, rotating bands for larger caliber shells, or on the inside surface of gun barrels.
  • the alloys of this invention are also suitable for forming powders.
  • the powder may be made directly from the molten alloy by pouring it into a high velocity stream of an inert gas such as nitrogen.
  • the finished alloys of this invention may be remelted and then poured into a high velocity stream of an inert gas. This latter procedure is possible due to the excellent remelt capability of the alloys without any significant loss of the line dispersion of the constituents.
  • EXAMPLE I ⁇ 68.4 grams of copper were melted in a graphite crucible at 1300 C. with a Lepel induction unit. 45.6 grams of lead were then added to the crucible. 2.28 grams of a commercially available rare earth mixture (Molybdenum Corp.) which was predominantly CeFCO3 and 0.57 gram of powdered graphite were also added to the crucible. The molten batch in the crucible was held at approximately 1300 C. for two minutes while stirring and then poured into a cold (room temperature) graphite crucible and allowed to cool. The resultant ingot was examined visually and by the photomicrographic technique. The ingot showed no lead segregation and had a tine dispersion of the constituents.
  • the rare earth mixture is known as bleached rare earth tiuorocarbonates, containing predominantly the cerium compound, with minor amounts of lanthanum, praseodymium and neodymium fluorocarbonates and trace amounts of other rare earth uorocarbonates, such as samarium and europium.
  • Example II The procedure of Example I was repeated on a larger scale with 9 pounds of copper, 6 pounds of lead, 123 grams of the same rare earth uorocarbonate mixture and 34 grams of powdered graphite. An excellent dispersion of the lead in the copper was obtained.
  • FIGS. 1 and 2 show magniiications of 50X and 250 respectively.
  • Example III The procedure of Example I was repeated with 9 pounds of copper, 6- pounds of lead, 123 grams of the same rare earth fluorocarbonate mixture, 34 grams of powdered graphite, and 68 grams of sodium carbonate. The resultant casting showed a fine dispersion of lead in copper.
  • the alloy was tested for hardness and was rated 37.0 on the Brinell scale.
  • Example IV For purpose of comparison, the procedure of Example I was repeated with 9 pounds of copper and 6 pounds of lead. The casting showed gross segregation of the lead in the copper. The Brinell hardness test resulted in a rating of 28.4.
  • Example V The procedure of Example I was repeated with 68 grams of copper, 45 grams of lead, 1 gram of a cerium oxide concentrate and 0.8 gram of powdered graphite.
  • the cerium oxide was a concentrate from a mixture of rare earths and contained about 98% cerium oxide.
  • the resultant alloy showed a good dispersion of lead in copper with little indication of segregation.
  • the alloy was of suitable quality for a bearing material although the dispersion of constituents was not as tine as the product of Example I.
  • Example VI The procedure of Example I was repeated with 68 grams of copper, 45 grams of lead, 1 gram of a cerium oxidecerium carbonate concentrate from a mixture of rare earth oxides and carbonates, and 0.8 gram powdered graphite. The casting obtained showed a good dispersion of lead in copper of a quality comparable to that made by the procedure of Example V. This procedure was repeated on a larger scale with comparable results, using 9 pounds of copper, 6 pounds of lead, 68 grams of the cerium oxide-cerium carbonate concentrate and 34 grams of powdered graphite.
  • Example VII The procedure of Example I was repeated with 68 grams of copper, 45 grams of lead, 4 grams of 98-199% yttrium oxide (Y203) concentrate from a mixture of rare earth oxides, and 0.8 gram of powdered graphite.
  • the resultant alloy had a good dispersion of lead in copper and was of a quality similar to the alloy of Example V.
  • segregation as used in this application is intended to refer to lead particles having a diameter greater than about mm.
  • the alloys of this invention have only a minor amount of segregation, preferably about zero percent.
  • the massive segregation which occurs without the homogeneity promoter of this invention is normally exhibited as a layering of the lead. .Minor segregation is evidenced by lead particles having a size of about 1-2 mm., but this is not a serious problem if such particles are well dispersed and constitute less than 5% of the lead volume.
  • the method of making a homogeneous copper-lead alloy comprising the step of adding an effective amount of a homogeneity promoter to a mixture of molten lead and copper, wherein said mixture comprises from 5-55% lead and from 95-45% copper, and wherein the total of said lead and copper in said mixture is at least and said promoter comprises elemental carbon and a rare earth metal compound selected from the group consisting of oxides, carbonates and halocarbonates.
  • a method according to claim 1 wherein the proportions of said promoter are from about 1-5 grams carbon and about 3-15 grams rare earth metal compound per pound of alloy.
  • said promoter comprises powdered graphite and cerium fluorocarbonate.
  • said promoter additionally comprises an alkali metal carbonate or alkaline earth metal carbonate.
  • a method according to claim 5 wherein the proportion of said carbonate is from 2-15 grams, for each pound of alloy.
  • said alloy contains up to 10% of a metal selected from the group consisting of tin, zinc and combinations thereof.
  • a homogeneous alloy comprising a mixture of cop- -per and lead, wherein said mixture comprises from 5-55% lead and from -45% copper, and wherein the total of said lead and copper in said mixture is at least 90%, and trace remanants of the products from a homogeneity promoter in molten copper and lead, said homogeneiety promoter comprising elemental carbon and a rare earth metal compound selected from the group consisting of oxides, carbonates and halocarbonates.
  • the alloy of claim 9 comprising about 5 to 55% lead, and about 95 to 45% copper, wherein the lead is in the form of a tine dispersion in a copper matrix, and the average diameter of said lead particles is between about 0.002 mm. to 0.02 mm.
  • the alloy of claim 9 comprising 20 to 45 lead, wherein the lead is in the form of a fine dispersion in a copper matrix, and the average .diameter of said lead particles is between about 0.002 mm. to 0.01 mm.

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • General Engineering & Computer Science (AREA)
  • Sliding-Contact Bearings (AREA)
  • Manufacture Of Alloys Or Alloy Compounds (AREA)
  • Powder Metallurgy (AREA)
  • Treatment Of Steel In Its Molten State (AREA)
  • Battery Electrode And Active Subsutance (AREA)
  • Manufacture Of Metal Powder And Suspensions Thereof (AREA)
US00062338A 1970-08-10 1970-08-10 Copper-lead alloy Expired - Lifetime US3720507A (en)

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US6233870A 1970-08-10 1970-08-10

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US (1) US3720507A (da)
JP (1) JPS5423884B1 (da)
BE (1) BE771149A (da)
CA (1) CA944591A (da)
DE (1) DE2139681C3 (da)
DK (1) DK136731B (da)
FR (1) FR2104139A5 (da)
GB (1) GB1321159A (da)
NL (1) NL7111024A (da)
SE (1) SE379786B (da)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4037522A (en) * 1974-09-24 1977-07-26 Taihou Kogyo Kabushiki Kaisha Vehicle air conditioning compressor
US4334926A (en) * 1979-03-14 1982-06-15 Taiho Kogyo Co., Ltd. Bearing material
US5242717A (en) * 1990-12-27 1993-09-07 Daido Metal Company Ltd. Method of producing a composite sliding member
US5279638A (en) * 1990-02-27 1994-01-18 Taiho Kogyo Co., Ltd. Sliding material

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
BE1025769B1 (nl) * 2017-12-14 2019-07-08 Metallo Belgium Verbeterde pyrometallurgische werkwijze

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4037522A (en) * 1974-09-24 1977-07-26 Taihou Kogyo Kabushiki Kaisha Vehicle air conditioning compressor
US4334926A (en) * 1979-03-14 1982-06-15 Taiho Kogyo Co., Ltd. Bearing material
US5279638A (en) * 1990-02-27 1994-01-18 Taiho Kogyo Co., Ltd. Sliding material
US5303617A (en) * 1990-02-27 1994-04-19 Taiho Kogyo Co., Ltd. Sliding material
US5242717A (en) * 1990-12-27 1993-09-07 Daido Metal Company Ltd. Method of producing a composite sliding member

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Publication number Publication date
NL7111024A (da) 1972-02-14
FR2104139A5 (da) 1972-04-14
JPS5423884B1 (da) 1979-08-17
DK136731C (da) 1978-04-24
CA944591A (en) 1974-04-02
DE2139681C3 (de) 1981-04-23
DK136731B (da) 1977-11-14
SE379786B (da) 1975-10-20
DE2139681A1 (de) 1972-02-17
BE771149A (fr) 1971-12-16
GB1321159A (en) 1973-06-20
DE2139681B2 (de) 1980-07-10

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