US5476632A
Expired / Lapsed
US
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Powder metal alloy process
Assignee: Stackpole Ltd
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Filing: 1992-09-09
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Granted: 1995-12-19
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Expires: 2012-09-09
Abstract
Abstract A process of forming a sintered article of powder metal comprising: selecting elemental iron powder; determining the desired properties of said sintered article and selecting, a quantity of carbon, and ferro alloy from the group of ferro manganese, ferro chromium, ferro molybdenum, ferro vanadium, ferro silicon and ferro boron; grinding said ferro alloy to a mean particle size of approximately 8 to 12 microns; introducing a lubricant while blending the carbon, ferro alloy, with said elemental iron powder; pressing the mixture to form the article; and then high temperature sintering the article at a temperature between 1,250° C. and 1,350° C. in a neutral or reducing atmosphere; so as to produce the sintered article of powdered metal; and includes the product formed thereby.
Inventors
- 👤 Rohith Shivanath
- 👤 Peter Jones
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 08:53
CPC Classifications
C; C22; C22C; C22C33/00; C22C33/02; C22C33/0257; C22C33/0264; C22C33/0207; C22C33/0271
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
79 words
A process of forming a sintered article of powder metal comprising; (a) blending (i) carbon, (ii) at least one ferro alloy powder selected from the group of separate ferro alloy particles of ferro manganese, ferro chromium, ferro molybdenum, ferro vanadium and ferro silicon (iii) lubricant with (iv) compressible iron powder, (b) pressing said blended mixture to form said article and (c) then high temperature sintering said article at a temperature of at least 1250° C. in a reducing atmosphere.
Claim 2
Dependent Claim
79 words
A process of forming a sintered article of powder metal comprising; (a) blending (i) carbon, (ii) at least one ferro alloy powder selected from the group of separate ferro alloy particles of ferro manganese, ferro chromium, ferro molybdenum, ferro vanadium and ferro silicon (iii) lubricant with (iv) compressible iron powder, (b) pressing said blended mixture to form said article and (c) then high temperature sintering said article at a temperature of at least 1250° C. in a reducing atmosphere.
Claim 3
Dependent Claim
39 words
A process as claimed in claim 1 wherein said ferro alloy has a mean particle size of approximately 8 to 12 microns and substantially all of said ferro alloy powder has a particle size of less than 25 microns.
Claim 4
Dependent Claim
31 words
A process as claimed in claim 1 wherein said sintered article of ferro alloy powder contains from 0.5% to 2.0% manganese from 0.2% to 0.85% carbon and the balance essentially iron.
Claim 5
Dependent Claim
79 words
A process of forming a sintered article of powder metal comprising. (a) blending (i) carbon, (ii) at least one ferro alloy powder selected from the group of separate ferro alloy particles of ferro manganese, ferro chromium, ferro molybdenum, ferro vanadium and ferro silicon (iii) lubricant with (iv) compressible iron powder, (b) pressing said blended mixture to form said article and (c) then high temperature sintering said article at, a temperature between 1250° C. tp 1350° C. under a vacuum.
Claim 6
Dependent Claim
79 words
A process of forming a sintered article of powder metal comprising. (a) blending (i) carbon, (ii) at least one ferro alloy powder selected from the group of separate ferro alloy particles of ferro manganese, ferro chromium, ferro molybdenum, ferro vanadium and ferro silicon (iii) lubricant with (iv) compressible iron powder, (b) pressing said blended mixture to form said article and (c) then high temperature sintering said article at, a temperature between 1250° C. tp 1350° C. under a vacuum.
Claim 7
Dependent Claim
19 words
A process as claimed in claim 3 wherein said reducing atmosphere comprises a blended nitrogen-hydrogen atmosphere, or dissociated ammonia.
Claim 8
Dependent Claim
36 words
A process as claimed in claim 1 wherein said sintered article of ferro alloy powder contains from 1.0% to 2.0% manganese from 0.5% to 0.85% carbon from 0% to 1.0% molybdenum and the balance essentially iron.
Claim 9
Dependent Claim
42 words
A process as claimed in claim 1 wherein said sintered article of ferro alloy powder contains from from 0.5% to 2.0% manganese from 0.5% to 1.5% molybdenum from 0% to 0.6% carbon from 0% to 1.0% chromium and the balance essentially iron.
Claim 10
Dependent Claim
20 words
A process as claimed in claim 5 wherein said ferro alloy powder is ground in an atmosphere of inert gas.
Claim 11
Dependent Claim
18 words
A process as claimed in claim 8 wherein said ferro alloy powder is ground in a jet mill.
Claim 12
Dependent Claim
47 words
A process as claimed in claim 1 wherein said high temperature sintering of said article in said atmosphere is undertaken with a dew point of not greater than -20° C. or under a vacuum to produce sintered parts which contain typically not more than 250 ppm oxygen.
Claim 13
Dependent Claim
34 words
A process as claimed in claim 10 wherein said articles are brought to a temperature not greater than 150° C. after sintering in a low dew point atmosphere of not higher than -30° C.
Claim 14
Dependent Claim
13 words
A process as claimed in claim 8 wherein said inert gas is cyclohexane.
Claim 15
Dependent Claim
13 words
A process as claimed in claim 8 wherein said inert gas is nitrogen.
Claim 16
Dependent Claim
171 words
A process of forming a sintered article of powder metal comprising: (a) selecting iron powder; (b) determining the desired properties of said sintered article and selecting; (i) a quantity of carbon; and (ii) at least one ferro alloy powder from the group of separate ferro alloy particles of ferro manganese, ferro chromium, ferro molybdenum, ferro vanadium and ferro silicon and selecting the quantity of same so as to control said desired properties of said sintered article; (c) grinding separately each said ferro alloy powder to a mean particle size of approximately 8 to 12 microns and substantially all of said ferro alloy powder having a particle size of less than 25 microns; (d) introducing a lubricant while blending said carbon, and ferro alloy powder with said iron powder; (e) pressing said mixture to form said article; (f) high temperature sintering said article at a temperature of at least 1,250° C. in a reducing atmosphere of 90% blended nitrogen and 10% hydrogen; so as to produce said sintered article of powdered metal.
Claim 17
Dependent Claim
171 words
A process of forming a sintered article of powder metal comprising: (a) selecting iron powder; (b) determining the desired properties of said sintered article and selecting; (i) a quantity of carbon; and (ii) at least one ferro alloy powder from the group of separate ferro alloy particles of ferro manganese, ferro chromium, ferro molybdenum, ferro vanadium and ferro silicon and selecting the quantity of same so as to control said desired properties of said sintered article; (c) grinding separately each said ferro alloy powder to a mean particle size of approximately 8 to 12 microns and substantially all of said ferro alloy powder having a particle size of less than 25 microns; (d) introducing a lubricant while blending said carbon, and ferro alloy powder with said iron powder; (e) pressing said mixture to form said article; (f) high temperature sintering said article at a temperature of at least 1,250° C. in a reducing atmosphere of 90% blended nitrogen and 10% hydrogen; so as to produce said sintered article of powdered metal.
Claim 18
Dependent Claim
50 words
A process as claimed in claim 14 wherein said ferro alloys powder are ground in a jet mill in an inert atmosphere such that the mean particle size is between 8 to 12 microns and the particle size of substantially all of said ferro alloy is less than 25 microns.
Claim 19
Dependent Claim
41 words
A process as claimed in claim 1 wherein said sintered article of ferro alloy powder contains from 0.5% to 2.0% manganese from 0.5% to 2.0% chromium from 0% to 1.0% molybdenum from 0.1% to 0.6% carbon and the balance essentially iron.
Claim 20
Dependent Claim
36 words
A process as claimed in claim 1 wherein said sintered article of ferro alloy powder contains from 0.5% to 2.0% chromium from 0% to 1.0% molybdenum from 0.1% to 0.6% carbon and the balance essentially iron.
References Cited (Backward Citations)
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