US4229210A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for the preparation of thixotropic slurries
Assignee: Olin Corp
•
Filing: 1977-12-12
•
Granted: 1980-10-21
•
Expires: 1997-12-12
Abstract
Abstract The invention relates to an improved method for the preparation and delivery of semi-solid thixotropic metal slurries for use in metal forming processes such as the rheocast and thixocast processes. The method includes inducing turbulent motion within the metal during solidification by electromagnetic or electrodynamic techniques under controlled temperature conditions so as to produce a highly fluid semi-solid slurry with a degenerate dendritic structure comprising solid spheroids dispersed in liquid. In the method of the preferred embodiment of the present invention, flow of the thixotropic metal slurry from the vibrating chamber is controlled by electromagnetic techniques and may be continuous or semi-continuous.
Inventors
- 👤 Joseph Winter
- 👤 Derek E. Tyler
- 👤 Michael J. Pryor
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 04:26
CPC Classifications
B; B01; B01F; B01F23/00; B01F33/00; B01F33/45; B01F33/451; C; C22; C22C; C22C1/00; C22C1/12; Y; Y10; Y10S; Y10S164/00; Y10S164/90
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
200 words
A process for producing a thixotropic metal or alloy composition containing discrete degenerate dendritic primary solid particles homogeneously suspended in a secondary phase having a lower melting point than said primary solid particles which comprises the steps of: (1) heating a metal or alloy to produce at least a partially liquid mixture comprising between 20 and 80% volume fraction primary solid particles; (2) supplying a current in the range of 500 to 10,000 amps to an AC induction coil at a frequency in the range of from 60 to 10,000 cps to form an induced electromagnetic force field of sufficient intensity to vigorously agitate said partially liquid mixture; (3) placing said partially liquid mixture within said induced electromagnetic force field; (4) holding said partially liquid mixture within said induced electromagnetic force field for sufficient duration to vigorously agitate said partially liquid mixture so as to convert said primay solid particles to discrete degenerate dendrites of substantially spheroidal configuration; and (5) simultaneously cooling said partially liquid mixture during said holding step at a cooling rate determined so as to counteract the heating effect of the induced current of said electromagnetic force field and maintain said volume fraction of primary solid particles.
Claim 2
Dependent Claim
200 words
A process for producing a thixotropic metal or alloy composition containing discrete degenerate dendritic primary solid particles homogeneously suspended in a secondary phase having a lower melting point than said primary solid particles which comprises the steps of: (1) heating a metal or alloy to produce at least a partially liquid mixture comprising between 20 and 80% volume fraction primary solid particles; (2) supplying a current in the range of 500 to 10,000 amps to an AC induction coil at a frequency in the range of from 60 to 10,000 cps to form an induced electromagnetic force field of sufficient intensity to vigorously agitate said partially liquid mixture; (3) placing said partially liquid mixture within said induced electromagnetic force field; (4) holding said partially liquid mixture within said induced electromagnetic force field for sufficient duration to vigorously agitate said partially liquid mixture so as to convert said primay solid particles to discrete degenerate dendrites of substantially spheroidal configuration; and (5) simultaneously cooling said partially liquid mixture during said holding step at a cooling rate determined so as to counteract the heating effect of the induced current of said electromagnetic force field and maintain said volume fraction of primary solid particles.
Claim 3
Dependent Claim
26 words
A process according to claim 1 wherein said metal is heated above its liquidus temperature and thereafter cooled to produce said at least partially liquid mixture.
Claim 4
Dependent Claim
25 words
A process according to claim 1 wherein said metal is heated to a temperature below its liquidus to produce said at least partially liquid mixture.
Claim 5
Dependent Claim
33 words
A process according to claim 1 wherein said step of holding said partially liquid mixture within said induced electromagnetic force field is carried out by utilizing a second distinct induced electromagnetic force field.
Claim 6
Dependent Claim
33 words
A process according to claim 4 wherein said second electromagnetic induced field is of sufficient force to prevent flow of said at least partially liquid mixture from within said first electromagnetic induced field.
Claim 7
Dependent Claim
47 words
A process according to claim 4 wherein said second electromagnetic induced field is of sufficient force to provide continuous flow of said at least partially liquid mixture from within said first electromagnetic induced field at a rate sufficient to produce said discrete degenerate dendritic primary solid particles.
References Cited (Backward Citations)
US2419373A
Cited
US2686864A
Cited
US2861302A
Cited
US3020323A
Cited
US3463365A
Cited
US3268963A
Cited
US3567429A
Cited
US3842895A
Cited
US3857696A
Cited
US3948650A
Cited
US3951651A
Cited
US4030534A
Cited
US3936298A
Cited
US3954455A
Cited
US3902544A
Cited
US4099960A
Cited
US4042007A
Cited
US4042008A
Cited
US4040467A
Cited
US3995678A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-10-21 | 1984-04-21 | 1984-10-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-10-21 | 1988-04-21 | 1988-10-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-10-21 | 1992-04-21 | 1992-10-21 | $7700.00 | Window Closed / Lapsed |