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
  • B22F1/00—Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties
  • B22F1/10—Metallic powder containing lubricating or binding agents; Metallic powder containing organic material
  • B22F1/103—Metallic powder containing lubricating or binding agents; Metallic powder containing organic material containing an organic binding agent comprising a mixture of, or obtained by reaction of, two or more components other than a solvent or a lubricating agent
• • 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
  • B22F1/00—Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties
  • B22F1/10—Metallic powder containing lubricating or binding agents; Metallic powder containing organic material
• • 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
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
  • C10M105/00—Lubricating compositions characterised by the base-material being a non-macromolecular organic compound
  • C10M105/56—Lubricating compositions characterised by the base-material being a non-macromolecular organic compound containing nitrogen
  • C10M105/68—Amides; Imides
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
  • C10M171/00—Lubricating compositions characterised by purely physical criteria, e.g. containing as base-material, thickener or additive, ingredients which are characterised exclusively by their numerically specified physical properties, i.e. containing ingredients which are physically well-defined but for which the chemical nature is either unspecified or only very vaguely indicated
  • C10M171/06—Particles of special shape or size
• • 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
  • B22F3/02—Compacting only
  • B22F2003/023—Lubricant mixed with the metal powder
• • 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
  • B22F3/12—Both compacting and sintering
  • B22F3/14—Both compacting and sintering simultaneously
  • B22F2003/145—Both compacting and sintering simultaneously by warm compacting, below debindering temperature

Definitions

• the present invention relates to metal powder compositions.
• the invention relates to iron-based compositions suitable for compaction at elevated temperatures.
• the powder metallurgy art generally uses different standard temperature regimes for the compaction of a metal powder to form a metal component. These include chill-pressing (pressing below ambient temperatures), cold-pressing (pressing at ambient temperatures), hot-pressing (pressing at temperatures above those at which the metal powder is capable of retaining work-hardening), and warm-pressing (pressing at temperatures between cold-pressing and hot-pressing).
• the lubricant according to the US patent 5,744,433 contains an oligomer of amide type, which has a weight-average molecular weight M w of 30,000 at the most. Very high densities and green strengths may be obtained by warm compacting powder compositions when the lubricant has a molecular weight above 4000, the preferred lubricant molecule having a molecular weight of about 6500. It has however been found that this lubricant has a tendency of sticking to the die wall, which requires frequent cleaning of the die. Another disadvantage is that the obtained green bodies are stained.
• the amide lubricant consists of the reaction product of a monocarboxylic acid, a dicarboxylic acid and a diamine.
• the only lubricant tested according to this patent is ADVAWAX® 450, the composition of which is not described in detail but the reaction product obtained includes i.a. ethylene bisstearamide according to Chemis-CIVS.
• Our experience of this product is that it is difficult to obtain a constant composition and quality, which in turn may result in components of varying quality. This may cause problems when the lubricant is used in large scale industrial production.
• An object of the present invention is to reduce or eliminate current problems associated with large scale production.
• a second object is to provide a new type of lubricant useful in metal compositions intended for compaction at elevated temperatures.
• a third object is to provide a metal powder for producing components without stains.
• a fourth object is to provide a metal composition including lubricant, which during the compaction of the metal powder does not deposit on the die wall.
• a powder composition comprising an iron-based powder and new oligomer amide type lubricant.
• the composition may also include one or more additives, such as binders, flow agents, processing aids and hard phases.
• the warm compaction may be performed by mixing an iron-based powder with the oligomer amide type lubricant and optionally a binder, preheating the powder composition and compacting the metal-powder composition in a pre-heated tool.
• the new amide type lubricant used according to the present invention may be represented by the following formula D-C ma -B-A-B-C mb -D wherein D is -H, COR, CNHR, wherein R is a straight or branched aliphatic or aromatic group including 2-21 C atoms C is the group -NH (CH 2 ) n CO- B is amino or carbonyl A is alkylen having 4-16 C atoms optionally including up to 4 O atoms ma is an integer 1-10 mb is an integer 1-10 n is an integer 5-11.
• D is COR, wherein R is an aliphatic group 16 - 20 C atoms, C is -NH (CH 2 ) n CO- wherein n is 5 or 11; B is amino; A is alkylen having 6-14 C atoms optionally including up to 3 O atoms, and ma and mb which may be the same or different, is an integer 2-5.
• Examples of preferred lubricants to be used in the iron based compositions according to the present invention are:
• the chemical differences between the new lubricant and the lubricant described in the US patent 5,744,433 are that the new molecule has a central diamine or diacid moiety and identical terminal groups on both ends.
• the chemical difference between the new lubricant and the lubricant described in the US patent 5,154,881 is that the new lubricant molecule includes the unit -NH(CH) n CO-. In contrast to the lubricant known from US 5 154 881 no EBS is formed when the lubricant according to the present invention is prepared.
• EBS has the chemical formula CH 3 (CH 2 ) 16 CO-HN(CH 2 ) 2 NH-OC(CH 2 ) 16 CH 3 ) is a molecule without lactam units which is in contrast to the lubricants according to the present invention.
• the preferred lubricants have a molecular weight between 1000 and 5000, most preferably between 1500 and 3000.
• the lubricant molecule may be prepared according standard procedures for amide oligomer as described in e.g. "Principles of Polymerization” third edition by George Odian (John Wiley & Sons, Inc.). According to the present invention the lubricant preferably consists of at least 80% of the amide having the formula described above. Thus up to 20% by weight of other types of lubricants may be added, as long as the advantageous properties of the new lubricant is not detrimentally affected.
• This lubricant which is added to the iron-based powder is preferably in the form of a solid powder, can make up 0.1-1% by weight of the metal-powder composition, preferably 0.2-0.8% by weight, based on the total amount of the metal-powder composition.
• the possibility of using the lubricant according to the present invention in low amounts is an especially advantageous feature of the invention, since it enables high densities to be achieved.
• iron-based powder encompasses powder essentially made up of pure iron; iron powder that has been pre-alloyed with other substances improving the strength, the hardening properties, the electromagnetic properties or other desirable properties of the end products; and particles of iron mixed with particles of such alloying elements (diffusion annealed mixture or purely mechanical mixture).
• alloying elements are copper, molybdenum, chromium, manganese, phosphorus, carbon in the form of graphite, and tungsten, which are used either separately or in combination, e.g. in the form of compounds (Fe 3 P and FeMo).
• the lubricants according to the invention are used in combination with iron-based powders having high compressibility.
• such powders have a low carbon content, preferably below 0.04% by weight.
• Such powders include e.g. Distaloy AE, Astaloy Mo and ASC 100.29, all of which are commercially available from Hoganas AB, Sweden.
• the new powder composition may contain one or more additives such as binders, flow agents, processing aids and hard phases.
• the binder may be added to the powder composition in accordance with the method described in U.S. Pat. No. 5,368,630 (which is hereby incorporated by reference) and may be organic compounds such as cellulose ester resins, hydroxyalkyl cellulose resins having 1-4 carbon atoms in the alkyl group, or thermoplastic phenolic resins.
• the flow agent which is preferably a silicon dioxide
• the flow agent is used in an amount from about 0.005 to about 2 percent by weight, preferably from about 0.01 to about 1 percent by weight, and more preferably from about 0.025 to about 0.5 percent by weight, based on the total weight of the metallurgical composition.
• the flow agent should have an average particle size below about 40 nanometers.
• Preferred silicon oxides are the silicon dioxide materials, both hydrophilic and hydrophobic forms, commercially available as the Aerosil line of silicon dioxides, such as the Aerosil 200 and R812 products, from Degussa Corporation.
• the processing aids used in the metal-powder composition may consist of talc, forsterite, manganese sulphide, sulphur, molybdenum disulphide, boron nitride, tellurium, selenium, barium difluoride and calcium difluoride, which are used either separately or in combination.
• the hard phases used in the metal-powder composition may consist of carbides of tungsten, vanadium, titanium, niobium, chromium, molybdenum, tantalum and zirconium, nitrides of aluminium, titanium, vanadium, molybdenum and chromium, Al 2 O 3 , and various ceramic materials.
• the new oligomer amide type lubricant according to the present invention is superior not only as regards the ejection force, the ejection energy, the springback but also when it comes to the appearance of the compacted component. Additionally the lubricant does not deposit on the die wall.
• the lubricant according to the present invention is superior as regards the ejection force, the ejection energy and the springback.
• GD g/cm 3
• Ejection Force N/mm 2
• Ejection Energy J/cm 2
• Springback %
• Lubricant according to the present invention 7.46 9.7 20.9 0.121
• Lubricant according to US patent 5 154 881 7.40 15.4 21.9 0.201
• Compaction pressure 700 MPa Temperature powder/Die 130°C/150°C
• the iron-based powder was Distaloy AE available from Höganäs AB, Sweden.
• This powder was mixed with 0.3% by weight of ultrafine graphite and 0.6% by weight of a lubricant according to the present invention.
• a flow enhancing agent Aerosil was added in an amount of 0.06% by weight.
• the following example discloses a comparison of densities of green bodies obtained with the oligomer amide lubricants which are used according to the present invention and which have different molecular weights.
• the iron-based powder was Distaloy AE available from Höganäs AB, Sweden.
• This powder was mixed with 0.3% by weight of ultrafine graphite and 0.6% by weight of a lubricant according to the present invention.
• a flow enhancing agent Aerosil was added in an amount of 0.06% by weight.
• the powder was heated to a temperature of 130°C and the temperature of die was 150°C.
• the compaction pressure was 700 MPa.
• the molecular weight of the oligomer amide lubricant is lower than (about) 2000 the properties of the powder composition becomes worse with regards to flow, and the lubricant will have a tendency of sticking to the die wall and the surface of the ejected compact.
• the sticky nature of such surfaces increases the risk of formation of rough surfaces on the final part owing to powder which may be collected onto the ejected compact.

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• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Organic Chemistry (AREA)
• Engineering & Computer Science (AREA)
• Manufacturing & Machinery (AREA)
• Mechanical Engineering (AREA)
• Lubricants (AREA)
• Powder Metallurgy (AREA)

Applications Claiming Priority (3)

Publications (2)

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Family Applications (1)

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• 2001
  • 2001-04-17 SE SE0101344A patent/SE0101344D0/xx unknown
  • 2001-05-10 US US09/852,024 patent/US20030029272A1/en not_active Abandoned
  • 2001-05-16 TW TW090111714A patent/TWI247041B/zh not_active IP Right Cessation
• 2002
  • 2002-04-17 WO PCT/SE2002/000762 patent/WO2002083345A1/en active IP Right Grant
  • 2002-04-17 EP EP02723031A patent/EP1390171B1/en not_active Expired - Lifetime
  • 2002-04-17 PL PL366558A patent/PL198679B1/pl unknown
  • 2002-04-17 CN CNB028083547A patent/CN1265920C/zh not_active Expired - Lifetime
  • 2002-04-17 ES ES02723031T patent/ES2229129T3/es not_active Expired - Lifetime
  • 2002-04-17 MX MXPA03009487A patent/MXPA03009487A/es active IP Right Grant
  • 2002-04-17 KR KR1020037013547A patent/KR100838925B1/ko active IP Right Grant
  • 2002-04-17 AU AU2002253770A patent/AU2002253770B2/en not_active Ceased
  • 2002-04-17 AT AT02723031T patent/ATE281899T1/de active
  • 2002-04-17 JP JP2002581132A patent/JP3908167B2/ja not_active Expired - Fee Related
  • 2002-04-17 RU RU2003133290/02A patent/RU2288072C2/ru not_active IP Right Cessation
  • 2002-04-17 DE DE60201903T patent/DE60201903T2/de not_active Expired - Lifetime
  • 2002-04-17 CA CA002443481A patent/CA2443481C/en not_active Expired - Lifetime
  • 2002-04-17 BR BRPI0208914-9A patent/BR0208914B1/pt not_active IP Right Cessation
• 2003
  • 2003-09-10 ZA ZA200307072A patent/ZA200307072B/en unknown

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