Magnetorheological polishing devices and methods

Details Magnetorheological polishing devices and methods Magnetorheological polishing devices and methods

1996-07-03

2003-01-07

Koslow, C. Melissa (Department: 1755)

Compositions

Magnetic

Flaw detection or magnetic clutch

C451S360000, C451S160000

Reexamination Certificate

active

06503414

ABSTRACT:

FIELD OF THE INVENTION
This invention relates to methods of polishing surfaces using magnetorheological fluids.
BACKGROUND OF THE INVENTION
Workpieces such as glass optical lenses, semiconductors, tubes, and ceramics have been polished in the art using one-piece polishing tools made of resin, rubber, polyurethane or other solid materials. The working surface of the polishing tool should conform to the workpiece surface. This makes polishing complex surfaces complicated, and difficult to adapt to large-scale production. Additionally, heat transfer from such a solid polishing tool is generally poor, and can result in superheated and deformed workpieces and polishing tools, thus causing damage to the geometry of the workpiece surface and/or the tool.
Co-pending application Ser. No. 966,919, filed Oct. 27, 1992, (abandoned), and 930,116, filed Aug. 14, 1992, (abandoned), disclose a magnetorheological fluid composition, a method of polishing an object using a magnetorheological fluid, and polishing devices which may be used according to the disclosed polishing method. While the method and devices disclosed in that application represent a significant improvement over the prior art, further advances that improve the devices, methods, and results achieved are possible.
SUMMARY OF THE INVENTION
This invention is directed to improved devices and methods for polishing objects in a magnetorheological polishing fluid (MP-fluid). More particularly, this invention is directed to a highly accurate method of polishing objects, in a magnetorheological fluid, which may be automatically controlled, and to improved polishing devices. The method of this invention comprises the steps of creating a polishing zone within a magnetorheological fluid; bringing an object to be polished into contact with the polishing zone of the fluid; determining the rate of removal of material from the surface of the object to be polished; calculating the operating parameters, such as magnetic field intensity, dwell time, and spindle velocity, for optimal polishing efficiency; and moving at least one of said object and said fluid with respect to the other according to the operating parameters.
The polishing device comprises an object to be polished, a magnetorheological fluid, which may or may not be contained within a vessel, a means for inducing a magnetic field, and a means for moving at least one of these components with respect to one or more of the other components. The object to be polished is brought into contact with the magnetorheological fluid and the magnetorheological fluid, the means for inducing a magnetic field, and/or the object to be polished are put into motion, thereby allowing all facets of the object to be exposed to the magnetorheological fluid.
In the method and devices of this invention, the magnetorheological fluid is acted upon by a magnetic field in the region where the fluid contacts the object to be polished. The magnetic field causes the MP-fluid to acquire the characteristics of a plasticized solid whose yield point depends on the magnetic field intensity and the viscosity. The yield point of the fluid is high enough that it forms an effective polishing surface, yet still permits movement of abrasive particles. The effective viscosity and elasticity of the magnetorheological fluid when acted upon by the magnetic field provides resistance to the abrasive particles such that the particles have sufficient force to abrade the workpiece.


REFERENCES:
patent: 1843198 (1932-02-01), Berguerand
patent: 1928036 (1933-09-01), Soderberg
patent: 2020714 (1935-11-01), Wulff
patent: 2670749 (1954-03-01), Germer
patent: 2735231 (1956-02-01), Simjian
patent: 2735232 (1956-02-01), Simjian
patent: 2736409 (1956-02-01), Logan
patent: 2751352 (1956-06-01), Bondi
patent: 2787854 (1957-04-01), Simjian
patent: 2883809 (1959-04-01), Simjian
patent: 2923100 (1960-02-01), Simjian
patent: 2994314 (1961-08-01), Wayland et al.
patent: 3395720 (1968-08-01), Brooks
patent: 3423880 (1969-01-01), Hershler
patent: 3500591 (1970-03-01), Gawronski et al.
patent: 3587613 (1971-06-01), Mark et al.
patent: 3665749 (1972-05-01), Brenner
patent: 3848363 (1974-11-01), Lovness et al.
patent: 3897350 (1975-07-01), Heiba et al.
patent: 3915006 (1975-10-01), Ayres
patent: 3917538 (1975-11-01), Rosensweig
patent: 4057939 (1977-11-01), Basi
patent: 4175930 (1979-11-01), Sakulevich et al.
patent: 4186528 (1980-02-01), Yascheritsyn et al.
patent: 4200003 (1980-04-01), Miller
patent: 4306386 (1981-12-01), Sakulevich et al.
patent: 4356098 (1982-10-01), Chagnon
patent: 4430239 (1984-02-01), Wyman
patent: 4599826 (1986-07-01), Podoprigora
patent: 4632315 (1986-12-01), Watanabe et al.
patent: 4632316 (1986-12-01), Watanabe et al.
patent: 4691774 (1987-09-01), Nelson
patent: RE32573 (1988-01-01), Furumara et al.
patent: 4730418 (1988-03-01), Sugawara et al.
patent: 4772407 (1988-09-01), Carlson
patent: 4802534 (1989-02-01), Larson et al.
patent: 4821466 (1989-04-01), Kato et al.
patent: 4839074 (1989-06-01), Rossi et al.
patent: 4920929 (1990-05-01), Bishop
patent: 4956944 (1990-09-01), Ando et al.
patent: 4974368 (1990-12-01), Miyamoto et al.
patent: 4986689 (1991-01-01), Drutchas
patent: 4992190 (1991-02-01), Shtarkman
patent: 4999954 (1991-03-01), Miyamoto et al.
patent: 5032307 (1991-07-01), Carlson
patent: 5044128 (1991-09-01), Nakano
patent: 5071541 (1991-12-01), Thompson
patent: 5076026 (1991-12-01), Mizuguchi et al.
patent: 5147573 (1992-09-01), Chagnon
patent: 5167850 (1992-12-01), Shtarkman
patent: 5599474 (1997-02-01), Weiss et al.
patent: 227372 (1985-10-01), None
patent: 680123 (1970-11-01), None
patent: 79-127916 (1979-10-01), None
patent: 63-83476 (1988-04-01), None
patent: 1-142905 (1989-06-01), None
patent: 686454 (1996-03-01), None
patent: 830662 (1981-05-01), None
patent: 888337 (1981-12-01), None
patent: 1089968 (1984-01-01), None
patent: 1154938 (1985-01-01), None
patent: 1193613 (1985-11-01), None
patent: 1318844 (1987-06-01), None
S.A. Demchuk, V.I. Kordonsky, Z.P. Shulman, “Magnetorheological Characteristics of Ferromagnetic Suspensions”,Magn. Hydrodynamics(USSR), No. 2, pp. 35-38 (1977).
E.A. Zal'tsgendler, A.V. Kolomentsev, V.I. Kordonskii et al., “Magnetorheological Converters”,Magn. Hydrodynamics,No. 4, pp. 105-110 (USSR 1985).
V.I. Kordonsky, Z.P. Shulman, S.R. Gorodkin et al., “Physical Properties of Magnetizable Structure—Reversible Media,”Journal of Magnetism and Magnetic Materials85, pp. 114-120 (1990).
“Magnetic Oil”,Life Magazine,Sep. 20, 1948.
Kordonsky, S.A. Demchuk “Magnetorheological Effect and Control of Transfer Processes”,Advances in Mechanicsvol. 12, No. 4 (1989), pp. 1-42.
T. Lucas, “Intelligent Fluids Come Out Of The Laboratories”,Technologies(Jan. 1990).
T. Kurobe et al., “Magnetic Field-Assisted Fine Finishing”,Precision Engineering,vol. 6, No. 3, pp. 119-124 (1984).
T. Kurobe et al., “Magnetic Field-Assisted Lapping”,Bull. Jap. Soc. Precision Eng'g,vol. 20, No. 1, pp. 49-51 (1986).
H. Suzuki et al., “Magnetic field-assisted polishing-application to a curved surface”,Precision Engineering4, 197-202 (Oct. 1989).
Umehara et al., “Magnetic fluid grinding of ceramic rollers”,Electromagnetic Forces and Applications,pp. 139-142 (1992).
Umehara et al., “Magnetic fluid grinding of ceramic flat surfaces”,Electromagnetic Forces and Applications,pp. 143-146 (1992).
Kashevskii, Kordonsky, Prokhorov, Demchuk and Gorodkin, “Relaxation of Viscous Stresses in Magnetorheological Suspensions”Magnitnaya Gidrodinamika,No. 2, pp. 11-19 (Apr.-Jun. 1990).
Watanabe, J. et al., “High Precision Polishing of Semiconductor Materials Using Hydrodynamic Principle,”IRP Annual,vol. 30 (1981), pp. 91-95.
Gormley, J. et al., “Hydroplane polishing of semiconductor crystals,”Rev. Sci. Instrum.,(Aug. 1981), pp. 1256-1259.
Saito, Y. et al., “Float Polishing Using Magnetic Fluid with Abrasive Grains,”Proceedings of the 6th International Conference on Production Engineering Osaka(1987), pp. 335-340.
Cook, L., “Chemical Processes In Glass Polishing,”Journal of Non-Crystalline Solids,vol. 120 (1990), pp. 152-171.
Wada, S. et a

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