US4177856A
Expired / Lapsed
US
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Critical gas boundary layer Reynolds number for enhanced processing of wide glassy alloy ribbons
Assignee: General Electric Co
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Filing: 1978-08-28
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Granted: 1979-12-11
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Expires: 1998-08-28
Abstract
Abstract A critical gas boundary layer Reynolds number has been defined to indicate processing conditions under which wide glassy alloy ribbons result when processing under various gaseous atmospheres and pressures and casting onto a moving substrate at an impingement angle α.
Inventors
- 👤 Howard H. Liebermann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 16:55
CPC Classifications
B; B22; B22D; B22D11/00; B22D11/06; B22D11/0637; B22D11/0697
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
196 words
A method for producing wide glassy alloy ribbons including the process steps of (a) casting a melt of a glassy metal alloy onto a surface wheel having a wheel diameter D and at a predetermined impingement angle αtherewith; (b) adjusting the substrate wheel speed S and the melt jet velocity to form a melt puddle of width w on the substrate wheel surface; (c) adjusting the prevalent ambient atmospheric pressure to a predetermined value, (d) producing a glassy alloy ribbon from the melt puddle, and (e) maintaining the Reynolds number Re for the gas boundary layer flow about the melt puddle at less than a critical value Re crit of about 2000±100 whereby the Reynolds number Re is expressed by the following formula Re=K(1-cos α)DSwP[M/η] wherein Re=Reynolds number K=constant which takes into consideration all conversion factors to obtain dimensional consistency α=impingement angle between the melt jet and the tangent to the substrate surface at the impingement point D=substrate wheel diameter S=substrate wheel speed w=ribbon or puddle width P=ambient atmospheric pressure under which casting is conducted M=molecular weight of ambient gas in which casting is conducted η=viscosity (20° C.) of ambient gas in which casting is conducted.
Claim 2
Independent Claim
196 words
A method for producing wide glassy alloy ribbons including the process steps of (a) casting a melt of a glassy metal alloy onto a surface wheel having a wheel diameter D and at a predetermined impingement angle αtherewith; (b) adjusting the substrate wheel speed S and the melt jet velocity to form a melt puddle of width w on the substrate wheel surface; (c) adjusting the prevalent ambient atmospheric pressure to a predetermined value, (d) producing a glassy alloy ribbon from the melt puddle, and (e) maintaining the Reynolds number Re for the gas boundary layer flow about the melt puddle at less than a critical value Re crit of about 2000±100 whereby the Reynolds number Re is expressed by the following formula Re=K(1-cos α)DSwP[M/η] wherein Re=Reynolds number K=constant which takes into consideration all conversion factors to obtain dimensional consistency α=impingement angle between the melt jet and the tangent to the substrate surface at the impingement point D=substrate wheel diameter S=substrate wheel speed w=ribbon or puddle width P=ambient atmospheric pressure under which casting is conducted M=molecular weight of ambient gas in which casting is conducted η=viscosity (20° C.) of ambient gas in which casting is conducted.
Claim 3
Dependent Claim
42 words
The method of claim 1 wherein K=2.868×10.sup.-8 when D and w are expressed in centimeters, S is expressed in revolutions per minute, P is expressed in millimeters of mercury, M is expressed in gram per mole, and η is expressed in poise.
Claim 4
Independent Claim
19 words
The method of either claims 1 or 2 wherein the impingement angle α may vary from 40° to 70°.
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) | 1982-12-10 | 1983-06-11 | 1983-12-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-12-10 | 1987-06-11 | 1987-12-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-12-10 | 1991-06-11 | 1991-12-11 | $7700.00 | Window Closed / Lapsed |