Claims
- 1. A method for producing rotors for stepping motors used in the movements of electronic timepieces, comprising:a. providing prealloyed rare earth magnetic alloys in particulate aggregate form, b. attriting a predetermined volume of said prealloyed rare earth particulate materials under a protective non-reactive fluid blanket having substantially higher density than that of water and breaking up the aggregates and mechanically removing adsorbed volatiles, moisture, atmospheric gases or contaminants from the surface of said prealloyed rare earth particulate materials or from the fresh surfaces generated during attrition, c. separating the contaminants thus removed from the deaggregated particulates, d. removing the protective fluid blanket from the thus decontaminated deaggregated particulates using vacuum distillation, e. desorbing the surface of the said particulates by applying a sufficiently high vacuum, f. allowing a predetermined volume of a suitable surfactant to adsorb onto the surface of the said particulates such that at least 25% and at most 50% of the said particulates' surface is coated with a monolayer of surfactant, g. dispersing said partially surfactant-coated particulates in a predetermined volume of a suitable degradable thermoplastic binder to form a homogeneous thermoplastic compound, h. tape casting said thermoplastic compound and exposing said tape casting to a magnetic field, i. punching a green rotor from the said tape and subsequently dewaxing and sintering said green rotor.
- 2. The method of claim 1 wherein the prealloyed magnetic materials are selected from the class of rare earth magnetic alloys such as Sm2Co17; SmCo5; Nd2Fe14B; Sm2Fe17N3, or blends of these alloys with other alloys.
- 3. The method of claim 2 wherein the said thermoplastic compound contains a UV curable ingredient and wherein the said cast tape is subjected to UV radiation immediately following magnetization.
- 4. A product made by the method of claim 3.
- 5. A product made by the method of claim 2.
- 6. The method of claim 1 wherein the prealloyed magnetic materials are selected from the class of rare earth magnetic alloys such as Sm2Co17; SmCo5; Nd2Fe14B; Sm2Fe17N3, or blends of these alloys with ferrites.
- 7. The method of claim 1, wherein said magnetic field exerts a strong pulsing magnetic field that exerts a torque onto magnetic particles in the tape.
- 8. The method of claim 1, wherein the magnetic field aligns magnetic particles in the tape, further comprising rapidly increasing the viscosity of the tape immediately following said alignment of said magnetic particles.
- 9. The method of claim 1, wherein the magnetic field aligns magnetic particles in the tape, further comprising rapidly increasing the viscosity of the tape simultaneously with said alignment of said magnetic particles.
- 10. The method of claim 1, further comprising rapidly increasing the viscosity of the tape immediately following tape casting of said thermoplastic compound in a magnetic field.
- 11. The method of claim 1, wherein the magnetic field aligns magnetic particles in the tape, and wherein said degradable thermoplastic binder includes a UV curable agent, the method further comprising rapidly increasing the viscosity of the tape simultaneous with said alignment of said magnetic particles by utilizing ultraviolet radiation.
- 12. The method of claim 1, wherein said tape is casted onto a moving cellulose acetate carrier film.
- 13. The method of claim 1, wherein said magnetic field exerts a strong pulsing magnetic field onto magnetic particles in the tape.
- 14. The method of claim 1, wherein said magnetic field exerts a strong pulsing magnetic field that exerts a torque onto magnetic particles in the tape.
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority to U.S. Provisional Patent Application Serial No. 60/284,688 filed on Apr. 13, 2001.
This invention is related to U.S. patent application Ser. No. 09/962,526 entitled: ‘Method For Controlling The Dimensions Of Bodies Made From Sinterable Materials’ and to Provisional Patent Application Serial No. 60/270,180 entitled: Method For Making Articles From Nanoparticulate Materials.
US Referenced Citations (10)
Foreign Referenced Citations (2)
Number |
Date |
Country |
57021946 |
Sep 1993 |
JP |
61291901 |
Sep 1993 |
JP |
Provisional Applications (1)
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Number |
Date |
Country |
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60/284688 |
Apr 2001 |
US |