US4861373A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Infiltrated powder metal part having improved impact strength tensile strength and dimensional control and method for making same
Assignee: SCM Metal Products Inc
•
Filing: 1988-03-08
•
Granted: 1989-08-29
•
Expires: 2008-03-08
Abstract
Abstract The present invention relates to an infiltrated ferrous powder metal part containing certain additives, yielding a radically improved unnotched impact strength without sacrificing tensile strength. Fatigue strength is also improved. In addition, improved dimensional control is obtained during infiltration. The microstructure is also improved, with smoothing or rounding of the formerly sharp angled copper filled pores. The invention also comprises the method of achieving these results.
Inventors
- 👤 Erhard Klar
- 👤 Mark Svilar
- 👤 David F. Berry
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 09:25
CPC Classifications
C; C22; C22C; C22C33/00; C22C33/02; C22C33/0242; B; B22; B22F; B22F2998/00
Claims Analysis
Total Claims: 38
Claim 1
Independent Claim
23 words
A copper infiltrated ferrous powder metal part having an effective amount of an additive for improving the microstructure resulting in rounded-off copper-filled pores.
Claim 2
Dependent Claim
23 words
A copper infiltrated ferrous powder metal part having an effective amount of an additive for improving the microstructure resulting in rounded-off copper-filled pores.
Claim 3
Dependent Claim
11 words
The metal part of claim 1 wherein the additive contains boron.
Claim 4
Dependent Claim
26 words
The metal part of claim 1 wherein the boron content is in the range of about 0.002% to about 0.20% by weight of the infiltrated part.
Claim 5
Dependent Claim
26 words
The metal part of claim 1 wherein the boron content is in the range of about 0.02% to about 0.08% by weight of the infiltrated part.
Claim 6
Dependent Claim
11 words
The metal part of claim 1 wherein the additive contains phosphorus.
Claim 7
Dependent Claim
11 words
The metal part of claim 1 wherein the additive contains arsenic.
Claim 8
Dependent Claim
11 words
The metal part of claim 1 wherein the additive contains antimony.
Claim 9
Dependent Claim
20 words
The metal part of claim 1 wherein the additive contains two or more of the additives boron, phosphorus, arsenic, antimony.
Claim 10
Dependent Claim
16 words
The metal part of claim 1 wherein the infiltrated phase consists of copper or copper alloy.
Claim 11
Dependent Claim
25 words
The metal part of claim 1 wherein carbon is present in the iron phase in the range of about 0.1% to about 1.1% by weight.
Claim 12
Dependent Claim
25 words
The metal part of claim 1 where carbon is present in the iron phase in the range of about 0.25% to about 0.8% by weight.
Claim 13
Dependent Claim
22 words
The metal part of claim 1 wherein the iron phase is plain carbon steel, tool steel, low alloy steel or stainless steel.
Claim 14
Dependent Claim
43 words
The metal part of claim 9 wherein the infiltrated phase is copper alloyed with alloying constituents selected from the group consisting of iron, tin, zinc, silver, lithium, silicon, manganese, chromium, zirconium, aluminum, nickel, phosphorus, arsenic, antimony, magnesium, cobalt and boron and combinations thereof.
Claim 15
Dependent Claim
29 words
The metal part of claim 1 having an unnotched Charpy impact strength of greater than about 28 ft. lb. and a tensile strength of greater than about 184 ksi.
Claim 16
Dependent Claim
27 words
The metal part of claim 2 having an unnotched impact strength of greater than about 28 ft. lb. and a tensile strength greater than about 184 ksi.
Claim 17
Dependent Claim
13 words
The metal part of claim 1 wherein distortion due to infiltration is minimized.
Claim 18
Dependent Claim
12 words
The metal part of claim 14 wherein distortion during infiltration is minimized.
Claim 19
Dependent Claim
72 words
A process for infiltrating ferrous powder metal parts which produces parts with impact strength as measured by unnotched Charpy test of greater than about 28 ft. lb. and a tensile strength of greater than about 184 ksi, said process comprising the steps of: a. adding an additive to the ferrous powder mix; b. pressing said powder mix into a compact; c. sintering said compact; d. infiltrating said sintered compact with an infiltrant.
Claim 20
Dependent Claim
72 words
A process for infiltrating ferrous powder metal parts which produces parts with impact strength as measured by unnotched Charpy test of greater than about 28 ft. lb. and a tensile strength of greater than about 184 ksi, said process comprising the steps of: a. adding an additive to the ferrous powder mix; b. pressing said powder mix into a compact; c. sintering said compact; d. infiltrating said sintered compact with an infiltrant.
Claim 21
Dependent Claim
12 words
Process of claim 18 wherein said infiltrant is copper or copper alloy.
Claim 22
Dependent Claim
18 words
The process of claim 18 wherein the additive contains boron in the form of boron or boron alloy.
Claim 23
Dependent Claim
21 words
The process of claim 18 wherein said ferrous powder mix contains carbon in the range of about 0.2% to about 1.1%.
Claim 24
Dependent Claim
21 words
The process of claim 18 wherein said ferrous powder mix contains carbon in the range of about 0.3% to about 0.9%.
Claim 25
Dependent Claim
15 words
The process of claim 18 wherein the additive to the ferrous powder mix is phosphorus.
Claim 26
Dependent Claim
15 words
The process of claim 18 wherein the additive to the ferrous powder mix is arsenic.
Claim 27
Dependent Claim
15 words
The process of claim 18 wherein the additive to the ferrous powder mix is antimony.
Claim 28
Dependent Claim
24 words
The process of claim 18 wherein the additive to the ferrous powder mix is two or more of the following: boron, phosphorus, arsenic, antimony.
Claim 29
Dependent Claim
18 words
The process of claim 18 wherein said sintering and infiltration take place under vacuum in two separate steps.
Claim 30
Dependent Claim
17 words
The process of claim 18 wherein said sintering and infiltration take place under vacuum in one step.
Claim 31
Dependent Claim
20 words
The process of claim 18 wherein sintering and infiltration take place in a reducing atmosphere with a low dew point.
Claim 32
Dependent Claim
12 words
The process of claim 18 wherein the reducing atmosphere is dissociated ammonia.
Claim 33
Dependent Claim
16 words
The process of claim 18 wherein boron in the infiltrant is a boron or boron alloy.
Claim 34
Dependent Claim
35 words
Process of claim 19 wherein said infiltrant powder mix contains copper with additives, in elemental or alloy form, selected from the group consisting of iron, tin, zinc, silver, lithium, silicon, cobalt, manganese, chromium, zirconium, aluminum.
Claim 35
Dependent Claim
17 words
Process of claim 19 comprising the additional step of austenitizing, quenching and tempering the infiltrated ferrous part.
Claim 36
Dependent Claim
87 words
A distortion free ferrous infiltrated powder metal part having improved dimension control, comprising: ferrous powder metal which is sintered in combination with carbon present in an amount ranging from 0.5 to 0.9%, the ferrous powder metal having pores; copper or a copper metal alloy infiltrated into the ferrous powder metal and carbon in an amount sufficient to fill the ferrous powder metal pores, and; boron present in an amount effective to (a) cause rounding off of the copper filled pores and (b) minimize distortion due to infiltration.
Claim 37
Dependent Claim
87 words
A distortion free ferrous infiltrated powder metal part having improved dimension control, comprising: ferrous powder metal which is sintered in combination with carbon present in an amount ranging from 0.5 to 0.9%, the ferrous powder metal having pores; copper or a copper metal alloy infiltrated into the ferrous powder metal and carbon in an amount sufficient to fill the ferrous powder metal pores, and; boron present in an amount effective to (a) cause rounding off of the copper filled pores and (b) minimize distortion due to infiltration.
Claim 38
Dependent Claim
19 words
The part described in claim 34 wherein the boron is present in an amount ranging from 0.002% to 0.02%.
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) | 1992-08-28 | 1993-02-27 | 1993-08-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-08-28 | 1997-02-27 | 1997-08-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-08-28 | 2001-02-27 | 2001-08-29 | $7700.00 | Window Closed / Lapsed |