US3918923A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Wear resistant sintered alloy
Assignee: Riken Piston Ring Industrial Co Ltd
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Filing: 1973-07-25
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Granted: 1975-11-11
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Expires: 1993-07-25
Abstract
Abstract An iron base sintered alloy having high wear resistance produced in a feasible and effective way, provided by compounding molybdenum disulfide or the like metal sulfide having its melting point higher than the sintering temperature of the alloy. Sulphur in the sulfide forms iron sulfide which improves wear resisting property of the alloy, while, metallic component of the sulfide diffuses throughout the base metal and serves to enhance the strength of matrix. Test results with apex seals of rotary piston engine revealed that wear amount of seals made of the alloy according to the present invention is extremely low as compared with those made of molybdenum-copper-cast iron, graphite or sintered alloy which is sintered and thereafter sulphurized by gas sulphurizing process.
Inventors
- 👤 Hiroshi Inoue
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 11:37
CPC Classifications
C; C22; C22C; C22C33/00; C22C33/02; C22C33/0207; C22C33/0221; F; F01; F01C; F01C19/00; F01C19/005
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
133 words
A METHOD OF PREPARING A WEAR-RESISTANT IRON-BASE ALLOY COMPRISING THE STEPS OF: PREPARING A POWDER MIXTURE COMPRISING 1.0-1.8% CARBON, 0.5-2.0% CHROMIUM, 0.5-1.0% NICKEL, 2.0-8.0% OF ONE OR MORE METAL SULFIDES SELECTED FROM A GROUP CONSISTING OF ALUMINUM SULFIDE, COBALT SULFIDE, TUNGSTEN SULFIDE, COPPER SULFIDE, LEAD SULFIDE, AND MOLYBDENUM SULFIDE, AND THE BALANCE IRON, COMPRESSING SAID POWDER MIXTURE INTO A FORM, SINTERING SAID FORM AT A TEMPERATURE BELOW THE MELTING POINT OF SAID ONE OR MORE METAL SULFIDES, MAINTAINING SAID FORM AT TEMPERATURE UP TO SAID SINTERING TEMPERATURE TO DISTRIBUTE THE SULFUR OF SAID ONE OR MORE METAL SULFIDE SUBSTANTIALLY IN THE MICROSTRUCTURE OF SAID ALLOY AS IRON SULFIDE, AND THE METAL OF SAID ONE OR MORE METAL SULFIDES SUBSTANTIALLY UNIFORMLY WITHIN THE MATRIX OF SAID ALLOY, AND COOLING SAID FORM TO ROOM TEMPERATURE.
Claim 2
Independent Claim
133 words
A METHOD OF PREPARING A WEAR-RESISTANT IRON-BASE ALLOY COMPRISING THE STEPS OF: PREPARING A POWDER MIXTURE COMPRISING 1.0-1.8% CARBON, 0.5-2.0% CHROMIUM, 0.5-1.0% NICKEL, 2.0-8.0% OF ONE OR MORE METAL SULFIDES SELECTED FROM A GROUP CONSISTING OF ALUMINUM SULFIDE, COBALT SULFIDE, TUNGSTEN SULFIDE, COPPER SULFIDE, LEAD SULFIDE, AND MOLYBDENUM SULFIDE, AND THE BALANCE IRON, COMPRESSING SAID POWDER MIXTURE INTO A FORM, SINTERING SAID FORM AT A TEMPERATURE BELOW THE MELTING POINT OF SAID ONE OR MORE METAL SULFIDES, MAINTAINING SAID FORM AT TEMPERATURE UP TO SAID SINTERING TEMPERATURE TO DISTRIBUTE THE SULFUR OF SAID ONE OR MORE METAL SULFIDE SUBSTANTIALLY IN THE MICROSTRUCTURE OF SAID ALLOY AS IRON SULFIDE, AND THE METAL OF SAID ONE OR MORE METAL SULFIDES SUBSTANTIALLY UNIFORMLY WITHIN THE MATRIX OF SAID ALLOY, AND COOLING SAID FORM TO ROOM TEMPERATURE.
Claim 3
Dependent Claim
17 words
The method as claimed in claim 1, wherein said one or more metal sulfides comprises molybdenum disulfide.
Claim 4
Dependent Claim
26 words
The method as claimed in claim 2, wherein said step of sintering comprises heating said form at 1,120*C for 30 minutes in a reducing gas atmosphere.
Claim 5
Dependent Claim
104 words
A WEAR RESISTANT SINTERED ALLOY PREPARED FROM A MIXTURE OF POWDERS COMPRISING: 1.0-1.8% CARBON, 0.5-2.0% CHROMIUM, 0.5-1.0% NICKEL, 2.0-8.0% OF ONE OR MORE METAL SULFIDES SELECTED FROM A GROUP CONSISTING OF ALMINUM SULFIDE, COBALT SULFIDE, TUNGSTEN SULFIDE, COPPER SULFIDE, LEAD SULFIDE, AND MOLYBDENUM SULFIDE, AND THE BLANCE IRON, SAID ALLOY HAVING A SINTERED MICROSTRUCTURE COMPRISING A PEARLITE MATRIX, FREE CEMENTITE LOCATED AT GRAIN BOUNDARIES, AND PORES, AND WHEREIN THE SULFUR OF SAID ONE OR MORE METAL SULFIDE IS DISTRIBUTED SUBSTANTIALLY IN SAID MICROSTRUCTURE AS IRON SULFIDE INCLUSIONS, AND THE METAL OF SAID ONE OR MORE METAL SULFIDES IS DISTRIBUTED SUBSTANTIALLY UNIFORMLY WITHIN SAID MATRIX.
Claim 6
Dependent Claim
104 words
A WEAR RESISTANT SINTERED ALLOY PREPARED FROM A MIXTURE OF POWDERS COMPRISING: 1.0-1.8% CARBON, 0.5-2.0% CHROMIUM, 0.5-1.0% NICKEL, 2.0-8.0% OF ONE OR MORE METAL SULFIDES SELECTED FROM A GROUP CONSISTING OF ALMINUM SULFIDE, COBALT SULFIDE, TUNGSTEN SULFIDE, COPPER SULFIDE, LEAD SULFIDE, AND MOLYBDENUM SULFIDE, AND THE BLANCE IRON, SAID ALLOY HAVING A SINTERED MICROSTRUCTURE COMPRISING A PEARLITE MATRIX, FREE CEMENTITE LOCATED AT GRAIN BOUNDARIES, AND PORES, AND WHEREIN THE SULFUR OF SAID ONE OR MORE METAL SULFIDE IS DISTRIBUTED SUBSTANTIALLY IN SAID MICROSTRUCTURE AS IRON SULFIDE INCLUSIONS, AND THE METAL OF SAID ONE OR MORE METAL SULFIDES IS DISTRIBUTED SUBSTANTIALLY UNIFORMLY WITHIN SAID MATRIX.
Claim 7
Dependent Claim
18 words
The sintered alloy as claimed in claim 4, wherein said one or more metal sulfides comprises molybdenum disulfide.
Claim 8
Dependent Claim
20 words
An apex seal for a rotary piston engiNe made from the wear resistant sintered alloy as claimed in claim 4.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-11-10 | 1979-05-12 | 1979-11-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-10 | 1983-05-12 | 1983-11-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-10 | 1987-05-12 | 1987-11-11 | $7700.00 | Window Closed / Lapsed |