USH639H - Method of making a ferrite element - Google Patents

Method of making a ferrite element Download PDF

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Publication number
USH639H
USH639H US07/188,934 US18893488A USH639H US H639 H USH639 H US H639H US 18893488 A US18893488 A US 18893488A US H639 H USH639 H US H639H
Authority
US
United States
Prior art keywords
ferrite
ferrite element
cavity
configuration
making
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
US07/188,934
Inventor
Richard A. Stern
Richard W. Babbitt
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
United States Department of the Army
Original Assignee
United States Department of the Army
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by United States Department of the Army filed Critical United States Department of the Army
Priority to US07/188,934 priority Critical patent/USH639H/en
Assigned to UNITED STATES OF AMERICA, THE, AS REPRESENTED BY THE SECRETARY OF THE ARMY reassignment UNITED STATES OF AMERICA, THE, AS REPRESENTED BY THE SECRETARY OF THE ARMY ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: BABBITT, RICHARD W., STERN, RICHARD A.
Application granted granted Critical
Publication of USH639H publication Critical patent/USH639H/en
Abandoned legal-status Critical Current

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Classifications

    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B41/00—After-treatment of mortars, concrete, artificial stone or ceramics; Treatment of natural stone
    • C04B41/009—After-treatment of mortars, concrete, artificial stone or ceramics; Treatment of natural stone characterised by the material treated
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B41/00—After-treatment of mortars, concrete, artificial stone or ceramics; Treatment of natural stone
    • C04B41/80—After-treatment of mortars, concrete, artificial stone or ceramics; Treatment of natural stone of only ceramics

Definitions

  • This invention relates in general to a method of making ferrite elements and in particular to a method of making ferrite elements for use in millimeter-wave ferrite control devices.
  • Ser. No. 171,325 described a method of making a ferrite circulator wherein ferrite material is arc plasma sprayed into the cavity area of a microstrip circuit, thus eliminating any chance of gaps between ferrite material and microstrip substrate material.
  • the general object of this invention is to provide a method of making ferrite elements for use in millimeter-wave ferrite control devices.
  • a more particular object of the invention is to provide such a method of making ferrite elements in volume numbers at lower costs eliminating the slower molding processes that requires additional processing steps.
  • a Y-shaped ferrite element that has very fine tapered feather edges on the three legs of the Y configuration.
  • a mold is first obtained having the configuration of the desired Y-shaped ferrite element.
  • the surface of the cavity is then coated with a "mold-release" solution so as to allow easy removal of the completed ferrite element.
  • the cavity is then filled with ferrite by arc-plasma-spraying, with minimal surface finishing required after completion of the spray process.
  • the ferrite element is then easily removed from the cavity and is complete in geometrical configuration, just having to be annealed to optimize the ferrite magnetic properties.
  • the configuration of the ferrite element made will generally be one having a low thickness to volume ratio.
  • the mold that contains the ferrite will generally be made of metal or other conventional molding material that will provide a smooth surface and accurate tolerances. Standard lecithin based solutions can be used as the "mold release" solutions.
  • arc-plasma-spraying as the term is used herein, is meant, a process of feeding ferrite powder into an electric arc where it is melted and directed to a target. Such a process is shown in the article "Arc Plasma Fabrication of Ferrite-Dielectric Composites" by R. W. Babbitt, American Ceramic Society Bulletin, June 1976, at page 566-568.
  • any free flowing ferrite powders can be used.
  • the method is generally short duration taking about 2 minutes.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Ceramic Engineering (AREA)
  • Materials Engineering (AREA)
  • Structural Engineering (AREA)
  • Organic Chemistry (AREA)
  • Coating By Spraying Or Casting (AREA)

Abstract

A ferrite element for millimeter-wave ferrite control devices is made by -plasma-spraying ferrite material into a mold type cavity having the configuration of the desired ferrite element.

Description

The invention described herein may be manufactured, used, and licensed by or for the Government for governmental purposes without the payment to us of any royalty thereon.
This invention relates in general to a method of making ferrite elements and in particular to a method of making ferrite elements for use in millimeter-wave ferrite control devices.
BACKGROUND OF THE INVENTION
The application is copending with U.S. patent application Ser. No. 171,325, filed March 21, 1988, for "Improved Method of Making a Ferrite Circulator" by R. A. Stern and R. W. Babbitt and assigned to a common assignee.
Ser. No. 171,325 described a method of making a ferrite circulator wherein ferrite material is arc plasma sprayed into the cavity area of a microstrip circuit, thus eliminating any chance of gaps between ferrite material and microstrip substrate material.
This still leaves the problem of making low cost ferrite elements in volume numbers for use in radar and communication applications. Heretofore, these ferrite elements have been made by slow molding processes requiring numerous processing steps.
SUMMARY OF THE INVENTION
The general object of this invention is to provide a method of making ferrite elements for use in millimeter-wave ferrite control devices. A more particular object of the invention is to provide such a method of making ferrite elements in volume numbers at lower costs eliminating the slower molding processes that requires additional processing steps.
It has now been found that the aforementioned objects can be attained by arc-plasma-spraying the ferrite materials into a mold type cavity having the configuration of the desired ferrite element or into an array of identical mold type cavities or impressions, each cavity having the configuration of the desired ferrite element.
DESCRIPTION OF THE PREFERRED EMBODIMENT
It is desired to fabricate a Y-shaped ferrite element that has very fine tapered feather edges on the three legs of the Y configuration. A mold is first obtained having the configuration of the desired Y-shaped ferrite element. The surface of the cavity is then coated with a "mold-release" solution so as to allow easy removal of the completed ferrite element. The cavity is then filled with ferrite by arc-plasma-spraying, with minimal surface finishing required after completion of the spray process. The ferrite element is then easily removed from the cavity and is complete in geometrical configuration, just having to be annealed to optimize the ferrite magnetic properties.
Thus, applicants have provided a method of effectively and efficiently making low-cost ferrite elements having unique configurations. The method results in fabrication of ferrite elements in volume numbers resulting in faster, easier, lower cost fabrication of ferrite elements heretofore made by slower molding processes that require additional processing steps.
The configuration of the ferrite element made will generally be one having a low thickness to volume ratio.
The mold that contains the ferrite will generally be made of metal or other conventional molding material that will provide a smooth surface and accurate tolerances. Standard lecithin based solutions can be used as the "mold release" solutions.
By arc-plasma-spraying as the term is used herein, is meant, a process of feeding ferrite powder into an electric arc where it is melted and directed to a target. Such a process is shown in the article "Arc Plasma Fabrication of Ferrite-Dielectric Composites" by R. W. Babbitt, American Ceramic Society Bulletin, June 1976, at page 566-568.
In the arc plasma or flame spray method, any free flowing ferrite powders can be used. The method is generally short duration taking about 2 minutes.
We wish it to be understood that we do not desire to be limited to the exact details as described for obvious modifications will occur to a person skilled in the art.

Claims (4)

What is claimed is:
1. Method of making a ferrite element for millimeter-wave ferrite control devices from a mold type cavity having the configuration of the desired ferrite element, said method comprising coating the surface of the cavity with a mold release solution so as to allow easy removal of the completed ferrite element, filling the cavity with ferrite by arc-plasma-spraying, removing the ferrite element from the cavity and annealing the ferrite element to optimize the ferrite magnetic properties.
2. Method according to claim 1 wherein the ferrite element is a Y-shaped ferrite element having very fine tapered feather edges on the three legs of the Y configuration.
3. Method of making ferrite elements for millimeter-wave ferrite control devices from an array of identical mold type cavities, each cavity having the configuration of the desired ferrite element said method comprising coating the surface of the respective cavities with a mold release solution so as to allow easy removal of the completed ferrite elements, filling the cavities with ferrite by arc-plasma-spraying, removing the ferrite elements from the cavities and annealing the ferrite elements to optimize the ferrite magnetic properties.
4. Method according to claim 3 wherein the ferrite element is a Y-shaped ferrite element having very fine tapered edges on the three legs of the Y configuration.
US07/188,934 1988-05-02 1988-05-02 Method of making a ferrite element Abandoned USH639H (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US07/188,934 USH639H (en) 1988-05-02 1988-05-02 Method of making a ferrite element

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US07/188,934 USH639H (en) 1988-05-02 1988-05-02 Method of making a ferrite element

Publications (1)

Publication Number Publication Date
USH639H true USH639H (en) 1989-06-06

Family

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Family Applications (1)

Application Number Title Priority Date Filing Date
US07/188,934 Abandoned USH639H (en) 1988-05-02 1988-05-02 Method of making a ferrite element

Country Status (1)

Country Link
US (1) USH639H (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20030209820A1 (en) * 2002-05-08 2003-11-13 Steward, Inc. Method and apparatus for making ferrite material products and products produced thereby
US20050263923A1 (en) * 2004-05-29 2005-12-01 Hopkins Noel P Method of producing a self supporting form from a coating material

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3405212A (en) 1966-02-17 1968-10-08 Weyerhaeuser Co Method of making metal clad tools
US3467583A (en) 1966-05-16 1969-09-16 Camin Lab Process for making a hollow body with protective inner layer for high-temperature applications
US3673293A (en) 1966-04-29 1972-06-27 Norton Abrasives Ltd Manufacture of plaster of paris mold having sprayed metal oxide linings and product
US4179795A (en) 1978-06-15 1979-12-25 The United States Of America As Represented By The Secretary Of The Army Method for forming a drive hole in arc plasma spray fabricated ferrite phasors
US4643322A (en) 1983-05-18 1987-02-17 James Dickson Can for containing material for consolidation into widgets and method of using the same

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3405212A (en) 1966-02-17 1968-10-08 Weyerhaeuser Co Method of making metal clad tools
US3673293A (en) 1966-04-29 1972-06-27 Norton Abrasives Ltd Manufacture of plaster of paris mold having sprayed metal oxide linings and product
US3467583A (en) 1966-05-16 1969-09-16 Camin Lab Process for making a hollow body with protective inner layer for high-temperature applications
US4179795A (en) 1978-06-15 1979-12-25 The United States Of America As Represented By The Secretary Of The Army Method for forming a drive hole in arc plasma spray fabricated ferrite phasors
US4643322A (en) 1983-05-18 1987-02-17 James Dickson Can for containing material for consolidation into widgets and method of using the same

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20030209820A1 (en) * 2002-05-08 2003-11-13 Steward, Inc. Method and apparatus for making ferrite material products and products produced thereby
WO2003096358A1 (en) * 2002-05-08 2003-11-20 Steward, Inc. Method and apparatus for making ferrite material products and products produced thereby
US7118728B2 (en) 2002-05-08 2006-10-10 Steward Advanced Materials, Inc. Method and apparatus for making ferrite material products and products produced thereby
US20050263923A1 (en) * 2004-05-29 2005-12-01 Hopkins Noel P Method of producing a self supporting form from a coating material

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Owner name: UNITED STATES OF AMERICA, THE, AS REPRESENTED BY T

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNORS:STERN, RICHARD A.;BABBITT, RICHARD W.;REEL/FRAME:005031/0579;SIGNING DATES FROM 19880422 TO 19880427

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