EP0097027A2 - Compactage de parties choisies d'objets en poudre métallique - Google Patents
Compactage de parties choisies d'objets en poudre métallique Download PDFInfo
- Publication number
- EP0097027A2 EP0097027A2 EP83303329A EP83303329A EP0097027A2 EP 0097027 A2 EP0097027 A2 EP 0097027A2 EP 83303329 A EP83303329 A EP 83303329A EP 83303329 A EP83303329 A EP 83303329A EP 0097027 A2 EP0097027 A2 EP 0097027A2
- Authority
- EP
- European Patent Office
- Prior art keywords
- powder
- portions
- compact
- length
- mold
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
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Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
- B22F3/10—Sintering only
- B22F3/11—Making porous workpieces or articles
- B22F3/1103—Making porous workpieces or articles with particular physical characteristics
- B22F3/1109—Inhomogenous pore distribution
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F5/00—Manufacture of workpieces or articles from metallic powder characterised by the special shape of the product
- B22F5/08—Manufacture of workpieces or articles from metallic powder characterised by the special shape of the product of toothed articles, e.g. gear wheels; of cam discs
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F2998/00—Supplementary information concerning processes or compositions relating to powder metallurgy
Definitions
- This invention relates to the field of powder metallurgy.
- metal powder is placed in the cavity of a mold and is pressed between upper and lower punches.
- the faces of the punches and the contour of the mold are configured to impart the desired shape to the finished parts.
- This practice is generally designed to provide as uniform a density as possible throughout the entire part. If a higher part density is desired, higher compacting pressures are used in molding the part.
- a pressed and sintered part is placed in a similarly shaped mold and repressed. Higher compacting and/or repressing pressures are limited, however, by factors such as available press tonnage capacity, excessive tooling stresses, and the quality of the molded part.
- a powder metal part with a higher density in one portion than in another portion it is desirable to have a powder metal part with a higher density in one portion than in another portion to obtain different mechanical properties in the different portions of the part.
- compacting punches are modified to allow a greater depth of powder fill in one portion relative to another portion. After compacting and sintering, the part is repressed in a similarly shaped mold.
- the punches are designed to repress only the thicker or over- filled portion to achieve further localized densification.
- the repressed part may be heat treated or resintered followed by heat treatment.
- This invention has particular application to the manufacture of powder metal gears, although it certainly has many other potential uses. Since prior powder metallurgy methods for gear production are economically attractive, powder metal gears are extensively employed. In the case of a gear, the portions requiring further densification are the teeth and the area of the gear body directly below the root diameter. Gear teeth are subject to severe static and impact loading as well as severe wear.
- This invention applies to the art of powder metallurgy.
- the powder metal may be derived by using any of the known processes including atcmizing, milling, shotting, reducing oxide powders, electrolytic deposition, or condensation from metal vapors, for example.
- the powders are pressed in a cold metal die. Pressures generally vary from five to fifty tons per square inch.
- a powder metal shape is formed in a mold with at least one multiple depth punch.
- the shape will have a portion with a greater length i.e., the linear dimension in the direction of pressing, than the length in an adjacent portion.
- both the top and bottom punches used for initial compaction are multiple depth punches.
- the ratio of greater length in the linear dimension to lesser length in the linear dimension after initial compaction is greater than 1:1 and less than 1.5:1. Most preferably, this ratio is greater than 1:1 and less than 1.2:1.
- the powder metal shape is sintered, but not necessarily as fully i.e., to as high a temperature and for as long a time, as it might have been according to prior practices. Specific examples of sintering times and temperatures for particular metals are given in the following examples.
- the sintering must be sufficient to cause bonding between abutting powder particles.
- the bonding should be sufficient to maintain the integrity of the particle bond upon repressing whereby the shape can be plastically deformed.
- the next step according to this invention is repressing in a mold with a punch that applies compacting forces to those portions of the sintered shape which initially had a greater length.
- the punches are simply flat they will bear upon the raised portions of the sintered shape applying pressure first to those portions.
- the portions of greater length typically have a lower density prior to pressing than the other portions but upon repressing the density of the raised portions becomes greater.
- the repressing mold must, of course, confine the side walls of the shape and thus will have a shape substantially identical with the mold used to form the powder shape. If a central bore is required, a mandrel will be required in both the powder compaction and the repressing molds.
- An optional additional step may comprise additional sintering of the repressed shape or merely reheating followed by a quenching.
- This invention has particular applicability to the manufacture of small gears wherein the gear teeth are provided extra density.
- FIG. 1A there is illustrated a mold 10 having a lower punch 11 and a mandrel 12 which slides within a bore in the lower punch.
- the walls of the mold are generated by a line substantially parallel to the axis of mandrel 12 and the bore in the lower punch.
- the walls of the mold may define the outer edges of gear teeth, for example.
- the top face of the lower punch is stepped to provide that the peripheral area is lower than the central area adjacent the mandrel. In the case of the mold for a spur gear, the area under the gear teeth is thus lower than the hub portion adjacent the mandrel. Note that if the mold is filled evenly to the top with powder metal, the length of the portion of the powder metal at the periphery of the mold is greater than the length of the powder metal in the central portion of the mold.
- an upper punch 14 has a bore to receive mandrel 12 and has a lower face that is stepped so that the peripheral area is higher than the central area.
- the resulting part has the cross section shown in Figure 2.
- the body portion length is less than the tooth portion length.
- the density of the longer peripheral tooth portion after compacting is less than the density of the shorter body portion.
- the punch face does not have to be ground at a right angle to its center line.
- a taper toward or away from the center line may be made which will give a variation of density in the repressed shape.
- the top and bottom punches may comprise multiple telescoping punches independently positionable to different depths within the mold.
- Ferrous-based powder metal parts were densified at specific locations to much higher densities as follows:
- the gears were sintered at 2050°F (1121 o C) for 30 minutes in a.neutral endogas atmosphere. After sintering they were sized to various lengths shown in Table 1 using flat-faced punches. They were then heat treated for 30 minutes at 1535 o F (835°C) in an endogas atmosphere, 0.7 percent carbon potential, and oil quenched. The results are set forth in the following table:
- Example II The identical powder fill as used in Example I was molded between ground top and bottom punches to a nominal density of 6.4 g/cm 3 so that the body of the gear was 0.500 inch (1.27 cm) long and the teeth were 0.580 inch (1.47 cm) long.
- the gears were sintered as in Example I and then sized with flat-faced punches to lengths shown in Table II. After heating for 30 minutes at 1535°F (835°C) in an endogas atmosphere, 0.7 percent carbon potential, and oil quenching, the following data were obtained.
- This example illustrates that the decrease of interconnected pores brought about by selective densification according to this invention inhibits the diffusion of carbon from a gaseous carburizing atmosphere.
- the gears were sintered in a non-carbonaceous atmosphere, dissociated ammonia, for 30 minutes at 2050 o F (1121 o C).
- Density measurements were made as shown in Table III for the various length gears.
- metallographic cross sections designed to show the depth of carbon pick-up from the heat treating atmosphere were prepared.
- the densities and the measured depth of carbon diffusion are shown in Table III.
- the unsized tooth of 0.578 inch length showed carburization throughout as seen in Figure 4.
- a density of 7.03,g/cm 3 0.510 inch tooth length
- the depth of carburization was irregular and was estimated as 0.56 mm.
- the depth was measured as 0.17 mm.
- the depth of carburization is about 0.10 mm.
Landscapes
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Mechanical Engineering (AREA)
- Powder Metallurgy (AREA)
- Gears, Cams (AREA)
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US38885182A | 1982-06-16 | 1982-06-16 | |
US388851 | 1982-06-16 |
Publications (2)
Publication Number | Publication Date |
---|---|
EP0097027A2 true EP0097027A2 (fr) | 1983-12-28 |
EP0097027A3 EP0097027A3 (en) | 1985-11-27 |
Family
ID=23535794
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP83303329A Withdrawn EP0097027A3 (en) | 1982-06-16 | 1983-06-09 | Densification of selected areas of powder metal parts |
Country Status (6)
Country | Link |
---|---|
EP (1) | EP0097027A3 (fr) |
JP (1) | JPS596301A (fr) |
BR (1) | BR8303108A (fr) |
DK (1) | DK275683A (fr) |
ES (1) | ES523285A1 (fr) |
GR (1) | GR78288B (fr) |
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4708912A (en) * | 1984-07-18 | 1987-11-24 | Sintermetallwerk Krebsoege Gmgh | Sintered metal body with at least one toothing |
EP0565161A1 (fr) * | 1992-04-04 | 1993-10-13 | Metallwerk Plansee Gesellschaft Mbh | Pièce pour engrenage à faible bruit |
EP0774316A1 (fr) * | 1995-11-16 | 1997-05-21 | Honda Giken Kogyo Kabushiki Kaisha | Procédé et installation pour la préparation d'ébauches de poudre comprimée |
EP0775806A1 (fr) * | 1994-05-30 | 1997-05-28 | Fuji Oozx Inc. | Procédé de fabrication d'un poussoir de moteur à combustion interne |
EP1179685A3 (fr) * | 2000-08-09 | 2002-05-29 | Mitsubishi Materials Corporation | Palier à garniture frettée imprégnée d'huile |
EP1839780A2 (fr) * | 2006-03-29 | 2007-10-03 | Hitachi Powdered Metals Co., Ltd. | Engrenage en métal fritté avec une étendue à haute densité et son procédé de production |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS63310904A (ja) * | 1987-06-12 | 1988-12-19 | Hitachi Ltd | 高密度焼結部品の製造方法 |
US7160351B2 (en) * | 2002-10-01 | 2007-01-09 | Pmg Ohio Corp. | Powder metal clutch races for one-way clutches and method of manufacture |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB610011A (en) * | 1943-09-01 | 1948-10-11 | American Electro Metal Corp | Method and press for compacting metallic powder |
FR1490434A (fr) * | 1966-08-29 | 1967-07-28 | Federal Mogul Corp | Procédé de fabrication de pièces compliquées en poudre frittée |
GB1148558A (en) * | 1966-10-10 | 1969-04-16 | Max Koehler | Piston ring and process for the production thereof |
US3445148A (en) * | 1967-06-08 | 1969-05-20 | Rotron Inc | Method of making porous bearings and products thereof |
DE1450035A1 (de) * | 1964-07-31 | 1969-05-22 | Schunk & Ebe Gmbh | Sinterlager mit verbesserten Laufeigenschaften und Verfahren zu seiner Herstellung |
-
1983
- 1983-06-09 EP EP83303329A patent/EP0097027A3/en not_active Withdrawn
- 1983-06-13 GR GR71645A patent/GR78288B/el unknown
- 1983-06-13 BR BR8303108A patent/BR8303108A/pt unknown
- 1983-06-15 DK DK275683A patent/DK275683A/da not_active Application Discontinuation
- 1983-06-15 ES ES523285A patent/ES523285A1/es not_active Expired
- 1983-06-16 JP JP58108531A patent/JPS596301A/ja active Pending
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB610011A (en) * | 1943-09-01 | 1948-10-11 | American Electro Metal Corp | Method and press for compacting metallic powder |
DE1450035A1 (de) * | 1964-07-31 | 1969-05-22 | Schunk & Ebe Gmbh | Sinterlager mit verbesserten Laufeigenschaften und Verfahren zu seiner Herstellung |
FR1490434A (fr) * | 1966-08-29 | 1967-07-28 | Federal Mogul Corp | Procédé de fabrication de pièces compliquées en poudre frittée |
GB1148558A (en) * | 1966-10-10 | 1969-04-16 | Max Koehler | Piston ring and process for the production thereof |
US3445148A (en) * | 1967-06-08 | 1969-05-20 | Rotron Inc | Method of making porous bearings and products thereof |
Cited By (14)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4708912A (en) * | 1984-07-18 | 1987-11-24 | Sintermetallwerk Krebsoege Gmgh | Sintered metal body with at least one toothing |
EP0565161A1 (fr) * | 1992-04-04 | 1993-10-13 | Metallwerk Plansee Gesellschaft Mbh | Pièce pour engrenage à faible bruit |
US5356721A (en) * | 1992-04-04 | 1994-10-18 | Sinterstahl Gesellschaft M.B.H. | Component for noise-damped transmission |
US5724734A (en) * | 1994-05-30 | 1998-03-10 | Fuji Oozx Inc. | Method of forming a tappet in an internal combustion engine |
EP0775806A1 (fr) * | 1994-05-30 | 1997-05-28 | Fuji Oozx Inc. | Procédé de fabrication d'un poussoir de moteur à combustion interne |
US6004120A (en) * | 1995-11-16 | 1999-12-21 | Honda Giken Kogyo Kabushiki Kaisha | Apparatus for manufacturing pressed powder body |
EP0774316A1 (fr) * | 1995-11-16 | 1997-05-21 | Honda Giken Kogyo Kabushiki Kaisha | Procédé et installation pour la préparation d'ébauches de poudre comprimée |
EP1179685A3 (fr) * | 2000-08-09 | 2002-05-29 | Mitsubishi Materials Corporation | Palier à garniture frettée imprégnée d'huile |
US6599018B2 (en) | 2000-08-09 | 2003-07-29 | Mitsubishi Materials Corporation | Oil-impregnant sintered bearing and manufacturing method thereof, and motor |
US7211219B2 (en) | 2000-08-09 | 2007-05-01 | Mitsubishi Materials Pmg Corporation | Oil-impregnant sintered bearing and manufacturing method thereof, and motor |
EP1839780A2 (fr) * | 2006-03-29 | 2007-10-03 | Hitachi Powdered Metals Co., Ltd. | Engrenage en métal fritté avec une étendue à haute densité et son procédé de production |
EP1839780A3 (fr) * | 2006-03-29 | 2007-12-12 | Hitachi Powdered Metals Co., Ltd. | Engrenage en métal fritté avec une étendue à haute densité et son procédé de production |
EP2052800A1 (fr) * | 2006-03-29 | 2009-04-29 | Hitachi Powdered Metals Co., Ltd. | Procédé de production d'un engrenage en métal fritté avec une étendue à haute densité |
US7905018B2 (en) | 2006-03-29 | 2011-03-15 | Hitachi Powdered Metals Co., Ltd. | Production method for sintered gear |
Also Published As
Publication number | Publication date |
---|---|
ES523285A1 (es) | 1984-05-16 |
BR8303108A (pt) | 1984-01-31 |
DK275683D0 (da) | 1983-06-15 |
GR78288B (fr) | 1984-09-26 |
DK275683A (da) | 1983-12-17 |
JPS596301A (ja) | 1984-01-13 |
EP0097027A3 (en) | 1985-11-27 |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
PUAI | Public reference made under article 153(3) epc to a published international application that has entered the european phase |
Free format text: ORIGINAL CODE: 0009012 |
|
AK | Designated contracting states |
Designated state(s): BE DE FR GB IT LU NL |
|
PUAL | Search report despatched |
Free format text: ORIGINAL CODE: 0009013 |
|
AK | Designated contracting states |
Designated state(s): BE DE FR GB IT LU NL |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN |
|
18D | Application deemed to be withdrawn |
Effective date: 19860102 |
|
RIN1 | Information on inventor provided before grant (corrected) |
Inventor name: AUNKST, CLAYTON W. Inventor name: REEN, ORVILLE W. |