CA2443481C - Iron powder composition including an amide type lubricant and a method to prepare it - Google Patents
Iron powder composition including an amide type lubricant and a method to prepare it Download PDFInfo
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- CA2443481C CA2443481C CA002443481A CA2443481A CA2443481C CA 2443481 C CA2443481 C CA 2443481C CA 002443481 A CA002443481 A CA 002443481A CA 2443481 A CA2443481 A CA 2443481A CA 2443481 C CA2443481 C CA 2443481C
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- 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
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- 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
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- 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)
Abstract
A powder composition for warm compaction comprising an iron-based powdered a lubricant powder consisting essentially of an amide described by the following formula D-Cm-B-A-B-Cm-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)n CO-;B is amino or carbonyl; A is alkylene having 4-16 C atoms optionally including up to 4 O atoms m is an integer 1-10 and n is an integer 5-11.
Description
Iron powder composition including an amide typ lubricant and a method to prepare it.
FIELD OF THE INVENTION
The present invention relates to metal powder compositions. Particularly the invention relates to iron-based compositions suitable for compaction at elevated temperatures.
BACKGROUND OF THE INVENTION
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).
Distinct advantages arise by pressing at tempera-tures above ambient temperature. The tensile strength and work hardening rate of most metals is reduced with in-creasing temperatures, and improved density and strength can be attained at lower compaction pressures. The ex-tremely elevated temperatures of hot-pressing, however, introduce processing problems and accelerate wear of the dies. Therefore, current efforts are being directed to-wards the development of metal compositions suitable for warm-pressing processes.
The US patent 4,955,789 (Musella) describes warm compaction in general. According to this patent, lubri-cants generally used for cold compaction, e.g. zinc ste-arate, can be used for warm compaction as well. In prac-tice, however, it has proved impossible to use zinc ste-arate or ethylene bisstearamide (commercially available as ACRAWAX~.), which at present are the lubricants most frequently used for cold compaction, for warm compaction.
The problems, which arise, are due to difficulties in filling the die in a satisfactory manner.
The US patents 5,744,433 (Storstrom et al) and 5,154,881 (Rutz) disclose metal powder compositions in-cluding amide lubricants, which are especially developed for warm compaction.
The lubricant according to the US patent 5,744,433 contains an oligomer of amide type, which has a weight-average molecular weight Mw 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 lubri-cant molecule having a molecular weight of about 6500.
It has however been found that this lubricant has a ten-dency of sticking to the die wall, which requires fre-quent cleaning of the die. Another disadvantage is that the obtained green bodies are stained.
In the US. Patent 5,154,881 the amide lubricant con-sists 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 com-position of which is not described in detail but the re-action product obtained includes i.a. ethylene bissteara-mide according to Chemis-CIVS. Our experience of this product is that it is difficult to obtain a constant com-position and quality, which in turn may result in compo-nents of varying quality. This may cause problems when the lubricant is used in large scale industrial produc-tion.
FIELD OF THE INVENTION
The present invention relates to metal powder compositions. Particularly the invention relates to iron-based compositions suitable for compaction at elevated temperatures.
BACKGROUND OF THE INVENTION
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).
Distinct advantages arise by pressing at tempera-tures above ambient temperature. The tensile strength and work hardening rate of most metals is reduced with in-creasing temperatures, and improved density and strength can be attained at lower compaction pressures. The ex-tremely elevated temperatures of hot-pressing, however, introduce processing problems and accelerate wear of the dies. Therefore, current efforts are being directed to-wards the development of metal compositions suitable for warm-pressing processes.
The US patent 4,955,789 (Musella) describes warm compaction in general. According to this patent, lubri-cants generally used for cold compaction, e.g. zinc ste-arate, can be used for warm compaction as well. In prac-tice, however, it has proved impossible to use zinc ste-arate or ethylene bisstearamide (commercially available as ACRAWAX~.), which at present are the lubricants most frequently used for cold compaction, for warm compaction.
The problems, which arise, are due to difficulties in filling the die in a satisfactory manner.
The US patents 5,744,433 (Storstrom et al) and 5,154,881 (Rutz) disclose metal powder compositions in-cluding amide lubricants, which are especially developed for warm compaction.
The lubricant according to the US patent 5,744,433 contains an oligomer of amide type, which has a weight-average molecular weight Mw 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 lubri-cant molecule having a molecular weight of about 6500.
It has however been found that this lubricant has a ten-dency of sticking to the die wall, which requires fre-quent cleaning of the die. Another disadvantage is that the obtained green bodies are stained.
In the US. Patent 5,154,881 the amide lubricant con-sists 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 com-position of which is not described in detail but the re-action product obtained includes i.a. ethylene bissteara-mide according to Chemis-CIVS. Our experience of this product is that it is difficult to obtain a constant com-position and quality, which in turn may result in compo-nents of varying quality. This may cause problems when the lubricant is used in large scale industrial produc-tion.
SUMMARY OF THE INVENTION
The present invention reduces or eliminates current problems associated with large scale production.
The present invention provides a new type of lubricant useful in metal compositions intended for compaction at elevated temperatures. The present invention also provides a metal powder for producing components without stains. The present invention also provides a metal composition including lubricant, which during the compaction of the metal powder does not deposit on the die wall.
In one aspect, the present invention provides 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.
DETAILED DESCRIPTION OF THE INVENTION
The new amide type lubricant used according to the present invention may be represented by the following formula:
2 5 D-Cn,a-B-A-B-C~,y,-D
wherein:
D is -H, COR or CNHR, wherein R is a straight or branched aliphatic or aromatic group including 2-21 C atoms;
C is the group -NH (CHZ) nC0-;
The present invention reduces or eliminates current problems associated with large scale production.
The present invention provides a new type of lubricant useful in metal compositions intended for compaction at elevated temperatures. The present invention also provides a metal powder for producing components without stains. The present invention also provides a metal composition including lubricant, which during the compaction of the metal powder does not deposit on the die wall.
In one aspect, the present invention provides 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.
DETAILED DESCRIPTION OF THE INVENTION
The new amide type lubricant used according to the present invention may be represented by the following formula:
2 5 D-Cn,a-B-A-B-C~,y,-D
wherein:
D is -H, COR or CNHR, wherein R is a straight or branched aliphatic or aromatic group including 2-21 C atoms;
C is the group -NH (CHZ) nC0-;
B is amino or carbonyl;
A is alkylene having 4-16 C atoms optionally including up to 4 0 atoms;
ma is an integer 1-10;
mb is an integer 1-10; and n is an integer 5-11.
It is preferred that D is COR, wherein R is an aliphatic group 16-20 C atoms; C is -NH(CHz)nC0-, wherein n is 5 or 11; B is amino; A is alkylene having 6-14 C; atoms optionally including up to 3 O atoms; and ma and mb, which may be the same or different, are an integer 2-5.
Examples of preferred lubricants to be used in the iron based compositions according to the present invention are:
CH,3 ( CHz ) i6C0- [ HN ( CHz ) 1100 ] z-HN ( CHz ) lzNH- [ CO ( CHz ) mNH ]
zC0 ( CHz ) i6CH3 ;
CH3 ( CHz ) 1600- [ HN ( CHz ) 1100 ] z-HN ( CHz ) lzNH- [ CO ( CHz ) mNH ]
sC0 ( CHz ) i6CH3 ;
CH3 ( CHz ) 1600- [ HN ( CHz ) mC0 ] 3-HN ( CHz ) izNH- [ CO ( CHz ) mNH ] sC0 ( CHz ) i6CHs ;
CH3 ( CHz ) 16C0- [ HN ( CHz ) mC0 ] s-HN ( CHz ) lzNH- [ CO ( CHz ) mNH ] 4C0 ( CHz ) i6CH3 ;
CH3 ( CHz ) 1600- [ HN ( CHz ) 1100 ] 4-HN ( CHz ) lzNH- [ CO ( CHz ) mNH ]
4C0 ( CHz ) i6CH3 ;
2 0 CH3 ( CHz ) 1600- [ HN ( CHz ) 1100 ] 4-HN ( CHz ) lzNH- [ CO ( CHz ) mNH
] sC0 ( CHz ) i6CH3 ;
and CH,3 ( CHz ) i6C0- [ HN ( CHz ) 1100 ] s-HN ( CHz ) lzNH- [ CO ( CHz ) mNH ]
sC0 ( CHz ) i6CH3 -Other examples are:
( CH3 ) CO-HN ( CHz ) SCO-HN ( CHz ) zNH-CO ( CHz ) SNH-CO ( CH3 ) having the MW 370.49;
CH; ( CHZ ) zoCO-HN ( CH2 ) 1100-HN ( CH2 ) laNH-CO ( CH2 ) liNH-CO ( CHZ ) 2oCHs having the MW 1240.10;
CH j ( CHZ ) zoCO- [ HN ( CHz ) 1100 ] lo-HN ( CHZ ) izNH- [ CO ( CH2 ) mNH ]
ioCO ( CH2 ) 2oCHs having the MW 8738.04;
A is alkylene having 4-16 C atoms optionally including up to 4 0 atoms;
ma is an integer 1-10;
mb is an integer 1-10; and n is an integer 5-11.
It is preferred that D is COR, wherein R is an aliphatic group 16-20 C atoms; C is -NH(CHz)nC0-, wherein n is 5 or 11; B is amino; A is alkylene having 6-14 C; atoms optionally including up to 3 O atoms; and ma and mb, which may be the same or different, are an integer 2-5.
Examples of preferred lubricants to be used in the iron based compositions according to the present invention are:
CH,3 ( CHz ) i6C0- [ HN ( CHz ) 1100 ] z-HN ( CHz ) lzNH- [ CO ( CHz ) mNH ]
zC0 ( CHz ) i6CH3 ;
CH3 ( CHz ) 1600- [ HN ( CHz ) 1100 ] z-HN ( CHz ) lzNH- [ CO ( CHz ) mNH ]
sC0 ( CHz ) i6CH3 ;
CH3 ( CHz ) 1600- [ HN ( CHz ) mC0 ] 3-HN ( CHz ) izNH- [ CO ( CHz ) mNH ] sC0 ( CHz ) i6CHs ;
CH3 ( CHz ) 16C0- [ HN ( CHz ) mC0 ] s-HN ( CHz ) lzNH- [ CO ( CHz ) mNH ] 4C0 ( CHz ) i6CH3 ;
CH3 ( CHz ) 1600- [ HN ( CHz ) 1100 ] 4-HN ( CHz ) lzNH- [ CO ( CHz ) mNH ]
4C0 ( CHz ) i6CH3 ;
2 0 CH3 ( CHz ) 1600- [ HN ( CHz ) 1100 ] 4-HN ( CHz ) lzNH- [ CO ( CHz ) mNH
] sC0 ( CHz ) i6CH3 ;
and CH,3 ( CHz ) i6C0- [ HN ( CHz ) 1100 ] s-HN ( CHz ) lzNH- [ CO ( CHz ) mNH ]
sC0 ( CHz ) i6CH3 -Other examples are:
( CH3 ) CO-HN ( CHz ) SCO-HN ( CHz ) zNH-CO ( CHz ) SNH-CO ( CH3 ) having the MW 370.49;
CH; ( CHZ ) zoCO-HN ( CH2 ) 1100-HN ( CH2 ) laNH-CO ( CH2 ) liNH-CO ( CHZ ) 2oCHs having the MW 1240.10;
CH j ( CHZ ) zoCO- [ HN ( CHz ) 1100 ] lo-HN ( CHZ ) izNH- [ CO ( CH2 ) mNH ]
ioCO ( CH2 ) 2oCHs having the MW 8738.04;
5 CH; ( CHZ ) 9C0- [ HN ( CHz ) 1100 ] s-HN ( CH2 ) 12NH- [ CO ( CHZ ) mNH ]
3C0 ( CH2 ) 4CH3 having the MW 1580.53;
CH; ( CH2 ) 4C0- [ HN ( CH2 ) SCO ] ~-HN ( CH2 ) 6NH- [ CO ( CHZ ) SNH ] NCO ( CHZ ) 4CH3 having the MW 1980.86;
CHI ( CH2 ) 2oC0- [ HN ( CHZ ) SCO ] ~-HN ( CHZ ) 6NH- [ CO ( CHz ) SNH ] NCO
( CHz ) zoCH3 having the MW 2429.69; and CHI ( CH2 ) i6NH- [ CO ( CH2 ) mNH ] 4-CO ( CH2 ) ioCO- [ HN ( CHZ ) 1100 ]
4HN ( CHZ ) 16CH3 having the MW 2283.73.
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(CH2)nC0-.
3C0 ( CH2 ) 4CH3 having the MW 1580.53;
CH; ( CH2 ) 4C0- [ HN ( CH2 ) SCO ] ~-HN ( CH2 ) 6NH- [ CO ( CHZ ) SNH ] NCO ( CHZ ) 4CH3 having the MW 1980.86;
CHI ( CH2 ) 2oC0- [ HN ( CHZ ) SCO ] ~-HN ( CHZ ) 6NH- [ CO ( CHz ) SNH ] NCO
( CHz ) zoCH3 having the MW 2429.69; and CHI ( CH2 ) i6NH- [ CO ( CH2 ) mNH ] 4-CO ( CH2 ) ioCO- [ HN ( CHZ ) 1100 ]
4HN ( CHZ ) 16CH3 having the MW 2283.73.
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(CH2)nC0-.
In contrast to the lubricant known from US 5 154 881 no ESS is formed when the lubricant according to the present invention is prepared. EBS which has the chemical formula CH3 ( CH2 ) isCO-HN ( CHz ) ZNH-CO ( CH2 ) isCHs is a molecule without lactam units which is in contrast to the lubricants according to the present invention.
As regards the molecular weight of the new lubricant molecule it has been found that the preferred lubricants have a molecular weight between 1000 and 5000, most pref-erably 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 800 of the amide having the formula described above. Thus up to 20~ by weight of other types of lubri-cants may be added, as long as the advantageous proper-ties 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-to by weight of the metal-powder composition, preferably 0.2-0.8o 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 in-vention, since it enables high densities to be achieved.
As used in the description and the appended claims, the expression "iron-based powder" encompasses powder es-3o sentially 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). Examples of alloying elements are copper, mo-lybdenum, 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 com-pounds (Fe3P and FeMo). Unexpectedly good results are obtained when the lubricants according to the invention are used in combination with iron-based powders having high compressibility. Generally, such powders have a low carbon content, preferably below 0.040 by weight. Such TM TM TM
powders include e.g. Distaloy AE, Astaloy Mo and ASC
100.29, all of which are commercially available from Hoganas AB, Sweden.
Apart from the iron-based powder and the lubricant, the new powder composition may contain one or more addi-tives 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 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.
A type of flow agent, which can be used according to the present invention, is disclosed in the US patent 5,782,954.
The flow agent, which is preferably a silicon dioxide, 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 met-allurgical composition. Furthermore, the flow agent should have an average particle size below about 40 nano-meters. Preferred silicon oxides are the silicon dioxide materials, both hydrophilic and hydrophobic forms, com-TM
mercially available as the Aerosil line of silicon diox-ides, such as the AerosilTM200 and R812TMproducts, from Degussa Corporation.
The processing aids used in the metal-powder compo-sition may consist of talc, forsterite, manganese sul-phide, sulphur, molybdenum disulphide, boron nitride, tellurium, selenium, barium difluoride and calcium di-fluoride, which are used either separately or in combina-tion.
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, A12 03, and various ceramic materials.
The invention is further illustrated by the follow-ing examples, which are to be interpreted only as exam-ples but should not limit the scope of protection.
wTrrtnr a ~
The following tables disclose a comparison of prop-erties between components prepared from powder mixtures including the lubricant according to the present inven-tion and the amide type lubricant disclosed in the US
patent 5,744, 433.
Table 1 Lubricant Compaction GD Ejec- Ejec- Spring-Pressure (g/cm3) tion tion back (MPa) Force Energy (o) (N/mm2) (J/cm2) Invention 500 7.14 11.5 19.3 0.147 " 600 7.29 11.4 23.3 0.162 " 700 7.38 11.8 24.6 0.192 OrgasolTM 500 7.09 11.9 29.9 0.191 3501*
600 7.22 13.8 40.0 0.187 700 7.30 16.0 48.5 0.229 Table 2 Lubricant Compac- Appearance tion Pressure (MPa) Green compact Die V~lall Invention 500 No stains No deposit " 600 Few stains No deposit 700 Few stains No deposit Orgasol 500 Many stains Some deposit 3501*
600 Many stains More deposit 700 Many stains More deposit Temperature Powder/Die: 120°C/120°C
* lubricant preferred according to US patent 5,744, 433 5 The iron-based powder was Distaloy AE available from Hoganas AB, Sweden. This powder was mixed with 0.3% by weight of ultrafine graphite and 0.6% by weight of a lu-bricant according to the present invention. A flow en-hancing agent Aerosil~ 200 was added in an amount of 10 0.06% by weight.
As can be seen 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.
nvTrrtr~r n The following table discloses a comparison of prop-erties between components prepared from powder mixtures including the lubricant according to the present inven-tion and the amide type lubricant disclosed in the US
patent 5,154,881.
As can be seen the lubricant according to the pre-sent invention is superior as regards the ejection force, the ejection energy and the springback.
Table 3 GD Ejection Ejection Springback (g/cm3) Force Energy (%) (N/mm2) (J/cm2) Lubricant 7.46 9.7 20.9 0.121 according to the present invention Lubricant 7.40 15.4 21.9 0.201 according to US
patent Compaction pressure 700 MPa Temperature powder/Die 130°C/150°C
The iron-based powder was Distaloy AE available from Hoganas AB, Sweden.
This powder was mixed with 0.3% by weight of ultra-fine 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.
nvTwrtnr n The following example discloses a comparison of den-sities of green bodies obtained with the oligomer amide lubricants which are used according to the present inven-tion and which have different molecular weights.
The iron-based powder was Distaloy AE available from Hoganas AB, Sweden.
This powder was mixed with 0.3% by weight of ultra-fine 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 0.060 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.
Molecular V~leight of Lubricant GD (g/cm') 2000 7,44 3000 7,41 4000 7,31 If 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.
As regards the molecular weight of the new lubricant molecule it has been found that the preferred lubricants have a molecular weight between 1000 and 5000, most pref-erably 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 800 of the amide having the formula described above. Thus up to 20~ by weight of other types of lubri-cants may be added, as long as the advantageous proper-ties 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-to by weight of the metal-powder composition, preferably 0.2-0.8o 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 in-vention, since it enables high densities to be achieved.
As used in the description and the appended claims, the expression "iron-based powder" encompasses powder es-3o sentially 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). Examples of alloying elements are copper, mo-lybdenum, 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 com-pounds (Fe3P and FeMo). Unexpectedly good results are obtained when the lubricants according to the invention are used in combination with iron-based powders having high compressibility. Generally, such powders have a low carbon content, preferably below 0.040 by weight. Such TM TM TM
powders include e.g. Distaloy AE, Astaloy Mo and ASC
100.29, all of which are commercially available from Hoganas AB, Sweden.
Apart from the iron-based powder and the lubricant, the new powder composition may contain one or more addi-tives 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 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.
A type of flow agent, which can be used according to the present invention, is disclosed in the US patent 5,782,954.
The flow agent, which is preferably a silicon dioxide, 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 met-allurgical composition. Furthermore, the flow agent should have an average particle size below about 40 nano-meters. Preferred silicon oxides are the silicon dioxide materials, both hydrophilic and hydrophobic forms, com-TM
mercially available as the Aerosil line of silicon diox-ides, such as the AerosilTM200 and R812TMproducts, from Degussa Corporation.
The processing aids used in the metal-powder compo-sition may consist of talc, forsterite, manganese sul-phide, sulphur, molybdenum disulphide, boron nitride, tellurium, selenium, barium difluoride and calcium di-fluoride, which are used either separately or in combina-tion.
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, A12 03, and various ceramic materials.
The invention is further illustrated by the follow-ing examples, which are to be interpreted only as exam-ples but should not limit the scope of protection.
wTrrtnr a ~
The following tables disclose a comparison of prop-erties between components prepared from powder mixtures including the lubricant according to the present inven-tion and the amide type lubricant disclosed in the US
patent 5,744, 433.
Table 1 Lubricant Compaction GD Ejec- Ejec- Spring-Pressure (g/cm3) tion tion back (MPa) Force Energy (o) (N/mm2) (J/cm2) Invention 500 7.14 11.5 19.3 0.147 " 600 7.29 11.4 23.3 0.162 " 700 7.38 11.8 24.6 0.192 OrgasolTM 500 7.09 11.9 29.9 0.191 3501*
600 7.22 13.8 40.0 0.187 700 7.30 16.0 48.5 0.229 Table 2 Lubricant Compac- Appearance tion Pressure (MPa) Green compact Die V~lall Invention 500 No stains No deposit " 600 Few stains No deposit 700 Few stains No deposit Orgasol 500 Many stains Some deposit 3501*
600 Many stains More deposit 700 Many stains More deposit Temperature Powder/Die: 120°C/120°C
* lubricant preferred according to US patent 5,744, 433 5 The iron-based powder was Distaloy AE available from Hoganas AB, Sweden. This powder was mixed with 0.3% by weight of ultrafine graphite and 0.6% by weight of a lu-bricant according to the present invention. A flow en-hancing agent Aerosil~ 200 was added in an amount of 10 0.06% by weight.
As can be seen 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.
nvTrrtr~r n The following table discloses a comparison of prop-erties between components prepared from powder mixtures including the lubricant according to the present inven-tion and the amide type lubricant disclosed in the US
patent 5,154,881.
As can be seen the lubricant according to the pre-sent invention is superior as regards the ejection force, the ejection energy and the springback.
Table 3 GD Ejection Ejection Springback (g/cm3) Force Energy (%) (N/mm2) (J/cm2) Lubricant 7.46 9.7 20.9 0.121 according to the present invention Lubricant 7.40 15.4 21.9 0.201 according to US
patent Compaction pressure 700 MPa Temperature powder/Die 130°C/150°C
The iron-based powder was Distaloy AE available from Hoganas AB, Sweden.
This powder was mixed with 0.3% by weight of ultra-fine 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.
nvTwrtnr n The following example discloses a comparison of den-sities of green bodies obtained with the oligomer amide lubricants which are used according to the present inven-tion and which have different molecular weights.
The iron-based powder was Distaloy AE available from Hoganas AB, Sweden.
This powder was mixed with 0.3% by weight of ultra-fine 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 0.060 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.
Molecular V~leight of Lubricant GD (g/cm') 2000 7,44 3000 7,41 4000 7,31 If 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.
Claims (10)
1. A powder composition for warm compaction comprising an iron-based powder and a lubricant powder, said lubricant consisting of an amide represented by the following formula:
D-C ma-B-A-B-C mb-D
wherein:
D is -H, COR or CNHR, wherein R is a straight or branched aliphatic or aromatic group with 2-21 C atoms;
C is the group -NH(CH2)n CO-;
B is amino or carbonyl;
A is alkylene having 4-16 C atoms and optionally including up to 4 O atoms;
ma is an integer 1-10;
mb is an integer 1-10; and n is an integer 5-11.
D-C ma-B-A-B-C mb-D
wherein:
D is -H, COR or CNHR, wherein R is a straight or branched aliphatic or aromatic group with 2-21 C atoms;
C is the group -NH(CH2)n CO-;
B is amino or carbonyl;
A is alkylene having 4-16 C atoms and optionally including up to 4 O atoms;
ma is an integer 1-10;
mb is an integer 1-10; and n is an integer 5-11.
2. A powder composition according to claim 1, wherein D
is COR, wherein R is an aliphatic group with 16-20 C atoms; C
is -NH(CH2)n CO-, wherein n is 5 or 11; B is amino; A is alkylene having 6-14 C atoms and optionally including up to 3 0 atoms; and ma and mb, independently are an integer 2-5.
is COR, wherein R is an aliphatic group with 16-20 C atoms; C
is -NH(CH2)n CO-, wherein n is 5 or 11; B is amino; A is alkylene having 6-14 C atoms and optionally including up to 3 0 atoms; and ma and mb, independently are an integer 2-5.
3. A powder composition according to claim 1 or 2, wherein the lubricant consists of a compound selected from the group consisting of:
CH3(CH2)16CO-[HN(CH2)11CO]2-HN(CH2)12NH-[CO(CH2)11NH]2CO(CH2)16CH3;
CH3(CH2)16CO-[HN(CH2)11CO]2-HN(CH2)12NH-[CO(CH2)11NH]3CO(CH2)16CH3;
CH2(CH2)16CO-[HN(CH2)11CO]3-HN(CH2)12NH-[CO(CH2)11NH]3CO(CH2)16CH3;
CH3(CH2)16CO-[HN(CH2)11CO]3-HN(CH2)12NH-[CO(CH2)11NH]4CO(CH2)16CH3;
CH3(CH2)16CO-[HN(CH2)11CO]4-HN(CH2)12NH-[CO(CH2)11NH]4CO(CH2)16CH3:
CH3(CH2)16CO-[HN(CH2)11CO]4-HN(CH2)12NH-[CO(CH2)11NH]5CO(CH2)16CH3;
and CH2(CH2)16CO-[HN(CH2)11CO]5-HN(CH2)12NH-[CO(CH2)11NH]5CO(CH2)16CH3.
CH3(CH2)16CO-[HN(CH2)11CO]2-HN(CH2)12NH-[CO(CH2)11NH]2CO(CH2)16CH3;
CH3(CH2)16CO-[HN(CH2)11CO]2-HN(CH2)12NH-[CO(CH2)11NH]3CO(CH2)16CH3;
CH2(CH2)16CO-[HN(CH2)11CO]3-HN(CH2)12NH-[CO(CH2)11NH]3CO(CH2)16CH3;
CH3(CH2)16CO-[HN(CH2)11CO]3-HN(CH2)12NH-[CO(CH2)11NH]4CO(CH2)16CH3;
CH3(CH2)16CO-[HN(CH2)11CO]4-HN(CH2)12NH-[CO(CH2)11NH]4CO(CH2)16CH3:
CH3(CH2)16CO-[HN(CH2)11CO]4-HN(CH2)12NH-[CO(CH2)11NH]5CO(CH2)16CH3;
and CH2(CH2)16CO-[HN(CH2)11CO]5-HN(CH2)12NH-[CO(CH2)11NH]5CO(CH2)16CH3.
4. A powder composition according to any one of claims 1 to 3, wherein said amide has a molecular weight of 2000 to 5000 and is present in said composition in an amount of less than 1% by weight.
5. A powder composition according to any one of claims 1 to 4, wherein the lubricant powder is provided in a concentration 0.2 to 0.8% by weight of the composition.
6. A powder composition according to any one of claims 1 to 5, which additionally contains one or more additives selected from the group consisting of binders, processing aids, and hard phases.
7. A powder composition according to any one of claims 1 to 6, wherein said iron-based powder is compressible, and at least 80% by weight of said lubricant powder is made up of said amide.
8. A powder composition according to any one of claims 1 to 7, wherein said composition is free from ethylenebisstearamide.
9. A powder composition according to any one of claims 1 to 8, wherein said iron-based powder has a carbon content of at most 0.04% by weight.
10. A method for producing a sintered product comprising:
(a) mixing an iron-based powder with a lubricant powder as defined in any one of claims 1 to 3;
(b) preheating the metal-powder composition;
(c) compacting the metal-powder composition in a pre-heated tool; and optionally (d) sintering the compacted metal-powder composition at a temperature above 1050° C to form a sintered product.
(a) mixing an iron-based powder with a lubricant powder as defined in any one of claims 1 to 3;
(b) preheating the metal-powder composition;
(c) compacting the metal-powder composition in a pre-heated tool; and optionally (d) sintering the compacted metal-powder composition at a temperature above 1050° C to form a sintered product.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| SE0101344A SE0101344D0 (en) | 2001-04-17 | 2001-04-17 | Iron powder composition |
| SE0101344-0 | 2001-04-17 | ||
| PCT/SE2002/000762 WO2002083345A1 (en) | 2001-04-17 | 2002-04-17 | Iron powder composition including an amide type lubricant and a method to prepare it |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2443481A1 CA2443481A1 (en) | 2002-10-24 |
| CA2443481C true CA2443481C (en) | 2007-03-13 |
Family
ID=20283795
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002443481A Expired - Lifetime CA2443481C (en) | 2001-04-17 | 2002-04-17 | Iron powder composition including an amide type lubricant and a method to prepare it |
Country Status (18)
| Country | Link |
|---|---|
| US (1) | US20030029272A1 (en) |
| EP (1) | EP1390171B1 (en) |
| JP (1) | JP3908167B2 (en) |
| KR (1) | KR100838925B1 (en) |
| CN (1) | CN1265920C (en) |
| AT (1) | ATE281899T1 (en) |
| AU (1) | AU2002253770B2 (en) |
| BR (1) | BR0208914B1 (en) |
| CA (1) | CA2443481C (en) |
| DE (1) | DE60201903T2 (en) |
| ES (1) | ES2229129T3 (en) |
| MX (1) | MXPA03009487A (en) |
| PL (1) | PL198679B1 (en) |
| RU (1) | RU2288072C2 (en) |
| SE (1) | SE0101344D0 (en) |
| TW (1) | TWI247041B (en) |
| WO (1) | WO2002083345A1 (en) |
| ZA (1) | ZA200307072B (en) |
Families Citing this family (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| SE0201825D0 (en) | 2002-06-14 | 2002-06-14 | Hoeganaes Ab | Hot compaction or steel powders |
| US7169208B2 (en) * | 2004-06-10 | 2007-01-30 | Inco Limited | Method and composition for dispersing extra-fine nickel powder |
| KR100861160B1 (en) * | 2004-06-10 | 2008-09-30 | 베일 인코 리미티드 | Method and composition for dispersing extra-fine nickel powder |
| US7314498B2 (en) * | 2004-10-19 | 2008-01-01 | Pmg Ohio Corp. | Sintered alloys for cam lobes and other high wear articles |
| DE102005023419B4 (en) * | 2005-05-20 | 2007-02-22 | Ems-Chemie Ag | Polyamide oligomers and their use |
| DE102005023420A1 (en) * | 2005-05-20 | 2006-11-23 | Ems-Chemie Ag | Polyamide molding compounds with improved flowability, their production and their use |
| US7722803B2 (en) * | 2006-07-27 | 2010-05-25 | Pmg Indiana Corp. | High carbon surface densified sintered steel products and method of production therefor |
| JP5841089B2 (en) * | 2013-03-13 | 2016-01-13 | 株式会社豊田中央研究所 | Molding powder, lubricant concentrated powder, and method for producing metal member |
| GB201409250D0 (en) * | 2014-05-23 | 2014-07-09 | H Gan S Ab Publ | New product |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US574433A (en) | 1897-01-05 | keithley | ||
| US538630A (en) * | 1895-04-30 | thomas | ||
| JP2733868B2 (en) * | 1990-09-25 | 1998-03-30 | 日立粉末冶金株式会社 | Molding lubricant for powder metallurgy |
| US5368630A (en) * | 1993-04-13 | 1994-11-29 | Hoeganaes Corporation | Metal powder compositions containing binding agents for elevated temperature compaction |
| SE9401922D0 (en) * | 1994-06-02 | 1994-06-02 | Hoeganaes Ab | Lubricant for metal powder compositions, metal powder composition containing th lubricant, method for making sintered products using the lubricant, and the use of same |
-
2001
- 2001-04-17 SE SE0101344A patent/SE0101344D0/en unknown
- 2001-05-10 US US09/852,024 patent/US20030029272A1/en not_active Abandoned
- 2001-05-16 TW TW090111714A patent/TWI247041B/en 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/en unknown
- 2002-04-17 CN CNB028083547A patent/CN1265920C/en not_active Expired - Lifetime
- 2002-04-17 ES ES02723031T patent/ES2229129T3/en not_active Expired - Lifetime
- 2002-04-17 MX MXPA03009487A patent/MXPA03009487A/en active IP Right Grant
- 2002-04-17 KR KR1020037013547A patent/KR100838925B1/en active IP Right Grant
- 2002-04-17 AU AU2002253770A patent/AU2002253770B2/en not_active Ceased
- 2002-04-17 AT AT02723031T patent/ATE281899T1/en active
- 2002-04-17 JP JP2002581132A patent/JP3908167B2/en not_active Expired - Fee Related
- 2002-04-17 RU RU2003133290/02A patent/RU2288072C2/en not_active IP Right Cessation
- 2002-04-17 DE DE60201903T patent/DE60201903T2/en not_active Expired - Lifetime
- 2002-04-17 CA CA002443481A patent/CA2443481C/en not_active Expired - Lifetime
- 2002-04-17 BR BRPI0208914-9A patent/BR0208914B1/en not_active IP Right Cessation
-
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- 2003-09-10 ZA ZA200307072A patent/ZA200307072B/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| MXPA03009487A (en) | 2004-02-12 |
| RU2288072C2 (en) | 2006-11-27 |
| ES2229129T3 (en) | 2005-04-16 |
| AU2002253770B2 (en) | 2004-05-27 |
| TWI247041B (en) | 2006-01-11 |
| PL366558A1 (en) | 2005-02-07 |
| CA2443481A1 (en) | 2002-10-24 |
| EP1390171B1 (en) | 2004-11-10 |
| EP1390171A1 (en) | 2004-02-25 |
| BR0208914A (en) | 2004-04-20 |
| KR100838925B1 (en) | 2008-06-16 |
| ZA200307072B (en) | 2004-09-10 |
| JP3908167B2 (en) | 2007-04-25 |
| ATE281899T1 (en) | 2004-11-15 |
| WO2002083345A1 (en) | 2002-10-24 |
| BR0208914B1 (en) | 2012-02-07 |
| DE60201903T2 (en) | 2005-11-03 |
| PL198679B1 (en) | 2008-07-31 |
| US20030029272A1 (en) | 2003-02-13 |
| CN1265920C (en) | 2006-07-26 |
| CN1503706A (en) | 2004-06-09 |
| KR20030085110A (en) | 2003-11-01 |
| SE0101344D0 (en) | 2001-04-17 |
| DE60201903D1 (en) | 2004-12-16 |
| RU2003133290A (en) | 2005-05-10 |
| JP2004524449A (en) | 2004-08-12 |
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