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US3790351A - Sintered alloy having wear resistance at high temperature - Google Patents

Sintered alloy having wear resistance at high temperature Download PDF

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Publication number
US3790351A
US3790351A US00186424A US3790351DA US3790351A US 3790351 A US3790351 A US 3790351A US 00186424 A US00186424 A US 00186424A US 3790351D A US3790351D A US 3790351DA US 3790351 A US3790351 A US 3790351A
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United States
Prior art keywords
percent
high temperature
wear resistance
copper
alloys
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Expired - Lifetime
Application number
US00186424A
Inventor
I Niimi
Y Serino
K Ishihara
K Hashimoto
K Ushitani
S Mitani
K Imanishi
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Toyota Motor Corp
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Toyota Motor Corp
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Classifications

    • 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
    • C22C1/04—Making non-ferrous alloys by powder metallurgy
    • C22C1/0425—Copper-based alloys
    • 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
    • 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
    • Y10S75/00—Specialized metallurgical processes, compositions for use therein, consolidated metal powder compositions, and loose metal particulate mixtures
    • Y10S75/95—Consolidated metal powder compositions of >95% theoretical density, e.g. wrought
    • 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
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T29/00—Metal working
    • Y10T29/49—Method of mechanical manufacture
    • Y10T29/49229—Prime mover or fluid pump making
    • Y10T29/49298—Poppet or I.C. engine valve or valve seat making
    • Y10T29/49306—Valve seat making

Definitions

  • ABSTRACT The present invention relates to sintered alloys having wear resistance at high temperature composed of a copper-base alloy containing copper as a principal constituent and 4 to 15 percent of tin, 4 to 25 percent of nickel, and 4 to 25 percent of chromium.
  • the present invention relates to copper-base sintered alloys having wear resistance and corrosion resistance at high temperature. These alloys are most suitable as construction materials for internal combustion engines, particularly the valving components of the engine.
  • Lead is commonly used as an additive for gasoline used in running internal combustion engines. As is well known, the lead additive prevents engine knock. The lead additive also has a lubricating effect which is produced by the adhesion of the lead onto the surface of the valves or valve seat.
  • Ieadfree gasoline and liquid propane gas (LPG) have been used as fuel in response to corrective measures to the airpollution problem.
  • LPG liquid propane gas
  • the use of such leadfree fuels results in a loss of the lubricating effect attributable to the lead and causes wear of conventional valving materials like cast iron or heat resistant steel. Eventually, the output of the engine is lowered.
  • the present invention eliminates the abovementioned defects by providing sintered alloys having excellent wear resistance and corrosion resistance at high temperature.
  • the sintered alloys according to the present invention are alloys containing chromium dispersed in copper-tin-nickel matrixes, namely copper-base sintered alloys composed of copper as a principal constituent, 4 to 15 percent tin, 4 to 25 percent nickel, and 4 to 25 percent chromium.
  • the density is more than 88 percent of the theoretical one.
  • the sintered alloys of the present invention have remarkable wear resistance and corrosion resistance at high temperature, these alloys are most suitable for valve seats of internal combustion engines in which leadfree gasoline or LPG is used as fuel.
  • the alloys are also applicable as bearing materials, especially for bearings subjected to high temperatures, such as, bearings for hot rollers.
  • copper excels in heat conductibility and corrosion resistance. It is remarkable that this constituent forms a copper oxide in conjunction with oxygen at high temperatures which imparts a lubricating effect thereby contributing to the wear resistance.
  • Tin as in the case of copper, forms a film oxide at high temperature thereby contributing to the wear resistance. It also advances the mechanical strength.
  • Nickel possesses a heat resistance and a corrosion resistance. It permeates into copper in the form of a solid solution thereby strengthening the matrix. However, less than 4 percent nickel has little effect, and more than 25 percent does not cause a remarkable effect considering the quantity added. Hence, the nickel composition is preferably 4 to 25 percent.
  • Chromium does not reduce in hardness even at high temperature. Also it forms a chromium oxide together with oxygen at high temperature thereby increasing the wear resistance. However, such effect is slight at less than 4 percent. With up to 35 percent chromium the wear resistance advances in proportion to the quantity added, but the mechanical strength diminishes. Therefore, the preferred maximum is 25 percent.
  • the density of the alloy when it is somewhat less than 88 percent of the theoretical one within the above-mentioned range of the constituents, the radiation at high temperature deteriorates and permanent strain of the engine structures results quite soon after engine start-up. This seriously affects the lifetime of the engine. Therefore, the density of the alloys should be more than 88 percent.
  • the sintered alloys of the present invention contain chromium which is hard and has excellent wear resistance at high temperature.
  • the chromium is dispersed in massive form into copper-tinnickel matrixes which are comparatively mild and have a good heat conductibility, wear resistance and corrosion resistance as well as a suitable material strength.
  • these alloys consist of both the phase of hardness and that of mildness and have an excellent wear resistance particularly at high temperature.
  • the heat conductibility is increased at high temperature and under heavy load thereby contributing to prevention of permanent strain.
  • the sintered alloys according to the present invention have the advantage of being simplified in their constituent materials and production method thereby maintaining easily a stable quality in mass production.
  • the present invention is described as follows.
  • EXAMPLE 1 utes in a neutral gas atmosphere, and the resultant sintered mass is again pressed under a pressure of 7 t/cm thereby increasing the density up to 7.6 g/cm.
  • a sintered alloy according to the present invention is obtained.
  • EXAMPLE 2 After the same powders as in Example 1 are arranged and mixed so as to give copper 74.8 percent, nickel 8.8 percent, tin 4.4 percent and chromium 12 percent, the mixture is formed under a forming pressure of 5 t/cm into a formed mass having a density of 7.5 g/cm. Then, the formed mass is sintered'at 860C. for 60 minutes in a neutral gas atmosphere. The resulting sintered mass is again pressed to increase the density up to 8.1 g/cm. A sintered alloy of the present invention is obtained.
  • the quantities of wear are indicated by the worn away quantities in millimeters in the direction of height of the specimens measured after the testing continued for a fixed duration hours) by the so-called sliding high-cycle impact tester.
  • This tester has a mechanism wherein 2,500 shocks a minute are given under a surface pressure of 30 kg/cm by means ofajig made of heat resistant steel while the angular specimens fixed to cast iron by special means are rotated 10 times a minute at an elevated temperature of 500 to 550C.
  • a sintered copper based alloy compact having wear resistance at high temperature consisting essentially of 4 to 15 percent tin, 4 to 25 percent nickel, 4 to 25 percent chromium. the balance being copper, the alloy having a density greater than 88 percent of the theoretical density.
  • a valve seat for an internal combustion engin comprising a sintered alloy as in claim 1.

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Powder Metallurgy (AREA)
  • Cylinder Crankcases Of Internal Combustion Engines (AREA)

Abstract

The present invention relates to sintered alloys having wear resistance at high temperature composed of a copper-base alloy containing copper as a principal constituent and 4 to 15 percent of tin, 4 to 25 percent of nickel, and 4 to 25 percent of chromium.

Description

Elnited @tates ?atent [1 1 Niimi et a1.
SINTERED ALLOY HAVING WEAR RESISTANCE AT HIGH TEMPERATURE Inventors: Itaru Niimi, Nagoya; Kametaro Hashimoto, Toyota; Kenzi Ushitani, Toyota; Yoichi Serino, Toyota; K0 Ishihara, Toyota; Seishu Mitani, Kyoto; Kunizo Imanishi, Nagoya, all of Japan Assignee: Toyota Jidosha Kogyo Kabushiki Kaisha, Toyota City, Japan Filed: Oct. 4, 1971 Appl. No.: 186,424
Foreign Application Priority Data '1 1 Feb. 5, 1974 9 [56] References Cited UNITED STATES PATENTS 2,753,859 7/1956 Bartlett 29/1821 X 2,849,789 9/1958 Thomson 2,887,765 5/l959 Thomson et al.
2,983,996 5/1961 Neely et al 29/182 Primary Examiner-Carl D. Quarforth Assistant Examiner-R. E. Schafer Attorney, Agent, or Firm-Arthur G. Connolly; Rudolf E. Hutz et al.
[5 7] ABSTRACT The present invention relates to sintered alloys having wear resistance at high temperature composed of a copper-base alloy containing copper as a principal constituent and 4 to 15 percent of tin, 4 to 25 percent of nickel, and 4 to 25 percent of chromium.
.. Elaine. NqPrawi tas SINTERED ALLOY HAVING WEAR RESISTANCE AT HIGH TEMPERATURE BACKGROUND OF THE INVENTION The present invention relates to copper-base sintered alloys having wear resistance and corrosion resistance at high temperature. These alloys are most suitable as construction materials for internal combustion engines, particularly the valving components of the engine.
Lead is commonly used as an additive for gasoline used in running internal combustion engines. As is well known, the lead additive prevents engine knock. The lead additive also has a lubricating effect which is produced by the adhesion of the lead onto the surface of the valves or valve seat. On the other hand, Ieadfree gasoline and liquid propane gas (LPG) have been used as fuel in response to corrective measures to the airpollution problem. However, the use of such leadfree fuels results in a loss of the lubricating effect attributable to the lead and causes wear of conventional valving materials like cast iron or heat resistant steel. Eventually, the output of the engine is lowered.
The present invention eliminates the abovementioned defects by providing sintered alloys having excellent wear resistance and corrosion resistance at high temperature.
SUMMARY OF THE INVENTION copper as a principal constituent, 4 to percent tin,-
4 to 25 percent nickel, and 4 to 25 percent chromium.
DETAILED DESCRIPTION OF THE INVENTION The sintered alloys according to the present invention are alloys containing chromium dispersed in copper-tin-nickel matrixes, namely copper-base sintered alloys composed of copper as a principal constituent, 4 to 15 percent tin, 4 to 25 percent nickel, and 4 to 25 percent chromium. The density is more than 88 percent of the theoretical one.
Since the sintered alloys of the present invention have remarkable wear resistance and corrosion resistance at high temperature, these alloys are most suitable for valve seats of internal combustion engines in which leadfree gasoline or LPG is used as fuel. The alloys are also applicable as bearing materials, especially for bearings subjected to high temperatures, such as, bearings for hot rollers.
The following description explains the function of each constituent element and the reason for restricting the composition range of the alloys. It is noted that percentages of the elements are all shown by weight.
Among the constituents of the sintered alloys of the present invention, copper excels in heat conductibility and corrosion resistance. It is remarkable that this constituent forms a copper oxide in conjunction with oxygen at high temperatures which imparts a lubricating effect thereby contributing to the wear resistance.
Tin, as in the case of copper, forms a film oxide at high temperature thereby contributing to the wear resistance. It also advances the mechanical strength.
However, such effect is little observed at less than 4 percent, and at more than 15 percent the mechanical strength sharply drops as well as the ability of holding chromium. Therefore, the range is determined as 4 to 15 percent for tin.
Nickel possesses a heat resistance and a corrosion resistance. It permeates into copper in the form of a solid solution thereby strengthening the matrix. However, less than 4 percent nickel has little effect, and more than 25 percent does not cause a remarkable effect considering the quantity added. Hence, the nickel composition is preferably 4 to 25 percent.
Chromium does not reduce in hardness even at high temperature. Also it forms a chromium oxide together with oxygen at high temperature thereby increasing the wear resistance. However, such effect is slight at less than 4 percent. With up to 35 percent chromium the wear resistance advances in proportion to the quantity added, but the mechanical strength diminishes. Therefore, the preferred maximum is 25 percent.
Concerning the density of the alloy, when it is somewhat less than 88 percent of the theoretical one within the above-mentioned range of the constituents, the radiation at high temperature deteriorates and permanent strain of the engine structures results quite soon after engine start-up. This seriously affects the lifetime of the engine. Therefore, the density of the alloys should be more than 88 percent.
As described above, the sintered alloys of the present invention contain chromium which is hard and has excellent wear resistance at high temperature. The chromium is dispersed in massive form into copper-tinnickel matrixes which are comparatively mild and have a good heat conductibility, wear resistance and corrosion resistance as well as a suitable material strength. Thus, these alloys consist of both the phase of hardness and that of mildness and have an excellent wear resistance particularly at high temperature. Furthermore, by providing the alloys with increased density, the heat conductibility is increased at high temperature and under heavy load thereby contributing to prevention of permanent strain.
It is further noted that the sintered alloys according to the present invention have the advantage of being simplified in their constituent materials and production method thereby maintaining easily a stable quality in mass production. The present invention is described as follows.
EXAMPLE 1 utes in a neutral gas atmosphere, and the resultant sintered mass is again pressed under a pressure of 7 t/cm thereby increasing the density up to 7.6 g/cm. A sintered alloy according to the present invention is obtained.
EXAMPLE 2 After the same powders as in Example 1 are arranged and mixed so as to give copper 74.8 percent, nickel 8.8 percent, tin 4.4 percent and chromium 12 percent, the mixture is formed under a forming pressure of 5 t/cm into a formed mass having a density of 7.5 g/cm. Then,,the formed mass is sintered'at 860C. for 60 minutes in a neutral gas atmosphere. The resulting sintered mass is again pressed to increase the density up to 8.1 g/cm. A sintered alloy of the present invention is obtained.
The following table shows, along with those of the conventional materials, the results of the tests made relating to the characteristics and the quantities of wears at high temperature of the alloys of the present invention as obtained in Examples 1 and 2.
TABLE Type of Composition Stensile Hardness Quantities of alloy of Strength Hv(0.2) wear (mm) Constituents (kg/(2m (7: by weight) Alloys of the Present Invention Example 1 56Cu-20Ni-4Sn-20Cr 400-450(Cr 0137 24 in the massive form) 120-140 '(matrix) Comparison of Examples Special Cast Fe-3i5C-25Si-lMn-O.5P-0.SCr-0.5Mo-0.1V 7.42
Iron 40 250-300 Heat Fe-0.4C-2Si-lSCr-ISNi-ZW OQMII 6188 Resistant 2903 10 Steel In the above table, the quantities of wear are indicated by the worn away quantities in millimeters in the direction of height of the specimens measured after the testing continued for a fixed duration hours) by the so-called sliding high-cycle impact tester. This tester has a mechanism wherein 2,500 shocks a minute are given under a surface pressure of 30 kg/cm by means ofajig made of heat resistant steel while the angular specimens fixed to cast iron by special means are rotated 10 times a minute at an elevated temperature of 500 to 550C.
What is claimed is:
1. A sintered copper based alloy compact having wear resistance at high temperature consisting essentially of 4 to 15 percent tin, 4 to 25 percent nickel, 4 to 25 percent chromium. the balance being copper, the alloy having a density greater than 88 percent of the theoretical density.
2. A valve seat for an internal combustion engin comprising a sintered alloy as in claim 1.

Claims (1)

  1. 2. A valve seat for an internal combustion engine comprising a sintered alloy as in claim 1.
US00186424A 1971-04-26 1971-10-04 Sintered alloy having wear resistance at high temperature Expired - Lifetime US3790351A (en)

Applications Claiming Priority (1)

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JP46027385A JPS4947124B1 (en) 1971-04-26 1971-04-26

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JP (1) JPS4947124B1 (en)
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GB (1) GB1307650A (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5125962A (en) * 1988-11-12 1992-06-30 Sintermetallwerk Krebsoge Gmbh Copper-based sintered material, its use, and method of producing molded parts from the sintered material
US5279638A (en) * 1990-02-27 1994-01-18 Taiho Kogyo Co., Ltd. Sliding material
US5443615A (en) * 1991-02-08 1995-08-22 Honda Giken Kogyo Kabushiki Kaisha Molded ceramic articles
US20040213692A1 (en) * 2003-04-28 2004-10-28 Zenzo Ishijima Copper based material of law thermal expansion and high thermal conductivity and method for producing the same

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2281078B (en) * 1993-08-16 1997-08-13 Smith International Rock bit bearing material

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2753859A (en) * 1952-03-07 1956-07-10 Thompson Prod Inc Valve seat insert
US2849789A (en) * 1953-12-11 1958-09-02 Gen Motors Corp Sintered powdered copper base metal and bearing formed thereof
US2887765A (en) * 1954-07-19 1959-05-26 Gen Motors Corp Sintered powdered copper base bearing
US2983996A (en) * 1958-07-30 1961-05-16 Mallory & Co Inc P R Copper-tungsten-molybdenum contact materials

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2753859A (en) * 1952-03-07 1956-07-10 Thompson Prod Inc Valve seat insert
US2849789A (en) * 1953-12-11 1958-09-02 Gen Motors Corp Sintered powdered copper base metal and bearing formed thereof
US2887765A (en) * 1954-07-19 1959-05-26 Gen Motors Corp Sintered powdered copper base bearing
US2983996A (en) * 1958-07-30 1961-05-16 Mallory & Co Inc P R Copper-tungsten-molybdenum contact materials

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5125962A (en) * 1988-11-12 1992-06-30 Sintermetallwerk Krebsoge Gmbh Copper-based sintered material, its use, and method of producing molded parts from the sintered material
US5279638A (en) * 1990-02-27 1994-01-18 Taiho Kogyo Co., Ltd. Sliding material
US5443615A (en) * 1991-02-08 1995-08-22 Honda Giken Kogyo Kabushiki Kaisha Molded ceramic articles
US20040213692A1 (en) * 2003-04-28 2004-10-28 Zenzo Ishijima Copper based material of law thermal expansion and high thermal conductivity and method for producing the same
US7378053B2 (en) * 2003-04-28 2008-05-27 Hitachi Powered Metals Co., Ltd. Method for producing copper-based material with low thermal expansion and high heat conductivity

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Publication number Publication date
GB1307650A (en) 1973-02-21
DE2150154A1 (en) 1972-11-16
DE2150154C3 (en) 1974-02-07
JPS4947124B1 (en) 1974-12-13
DE2150154B2 (en) 1973-07-19

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