Laminated composite of magnetic alloy powder and ceramic powder and process for making same

• US 5,935,722 A
• Filed: 09/03/1997
• Issued: 08/10/1999
• Est. Priority Date: 09/03/1997
• Status: Expired due to Fees

• Current Assignee: Lockheed Martin Energy Research Corporation (Martin Marietta Corporation)
• Original Assignee: Lockheed Martin Energy Research Corporation (Martin Marietta Corporation)
• Inventors: Kim, Hyoun-Ee, Moorhead, Arthur J.
• Primary Examiner(s): KILIMAN, LESZEK B
• Application Number:
  US08/922,940
• Time in Patent Office: 706 Days
• Field of Search: 478/694 B, 478/694 BA, 478/694 BH, 478/900, 478/545, 478/570, 427/383.5, 419/10, 419/19, 419/30, 419/35, 419/42, 419/49, 264/113, 264/125, 148/105, 148/121, 148/217
• US Class Current: 428/846.2
• CPC Class Codes: C04B 2235/6581 Total pressure below 1 atmosphere, e.g. vacuum
• CPC Class Codes: C04B 2237/123 based on iron group metals, e.g. steel
• CPC Class Codes: C04B 2237/341 Silica or silicates
• CPC Class Codes: C04B 2237/343 Alumina or aluminates
• CPC Class Codes: C04B 37/021 in a direct manner, e.g. direct copper bonding [DCB]
• CPC Class Codes: H01F 41/0233 Manufacturing of magnetic circuits made from sheets magnetic cores made from sheets H01F27/245; soft magnetic alloys in the form of sheets H01F1/16
• CPC Class Codes: H01F 41/0246 Manufacturing of magnetic circuits by moulding or by pressing powder magnetic cores made by moulding or by pressing powder H01F27/255; soft magnetic particles H01F1/20, H01F1/36
• CPC Class Codes: Y10S 428/90 Magnetic feature
• CPC Class Codes: Y10T 428/12007 Component of composite having metal continuous phase interengaged with nonmetal continuous phase
• CPC Class Codes: Y10T 428/12181 Composite powder [e.g., coated, etc.]

Abstract

A laminated composite structure of alternating metal powder layers, and layers formed of an inorganic bonding media powder, and a method for manufacturing same are discosed. The method includes the steps of assembling in a cavity alternating layers of a metal powder and an inorganic bonding media of a ceramic, glass, and glass-ceramic. Heat, with or without pressure, is applied to the alternating layers until the particles of the metal powder are sintered together and bonded into the laminated composite structure by the layers of sintered inorganic bonding media to form a strong composite structure. The method finds particular application in the manufacture of high performance magnets wherein the metal powder is a magnetic alloy powder.

Claims

1. A method for manufacturing a laminated composite structure, comprising the steps of:

assembling in a cavity alternating layers of uncoated metal powder particles and an inorganic bonding media, said inorganic bonding media selected from at least one of the group of powders consisting of a ceramic, glass, and glass-ceramic; and

,

applying heat to said alternating layers until the particles of each said layer of said metal powder are sintered together, each said layer of said inorganic bonding media is sintered, and said alternating sintered layers are bonded to one another to form a strong laminated composite structure.

2. The method according to claim 1 wherein the alternating layers are densified through the application of pressure using a uniaxial hot pressing process.

3. The method according to claim 2 wherein said cavity is defined by a graphite die.

4. The method according to claim 1 wherein said alternating layers are densified through the application of gas pressure to a flexible die using a hot isostatic pressing process.

5. The method according to claim 1 wherein said metal powder is a magnetic alloy powder.

6. The method according to claim 1 wherein said metal powder is a non-magnetic alloy powder.

7. The method according to claim 1 wherein said bonding media has a coefficient of thermal expansion which approximates that of said metal powder.

8. The method according to claim 1 wherein a surface of the particles comprising said metal powder are oxidized prior to the step of assembling said alternating layers in said cavity.

9. A laminated composite structure comprised of:

alternating layers of uncoated metal powder particles and an inorganic bonding media selected from at least one of the group of powders consisting of a ceramic, glass, and glass-ceramic;

the particles comprising the metal powder sintered together and bonded into said laminated composite structure by the layers of sintered inorganic bonding media to form a strong composite structure.

10. The laminated composite structure according to claim 9 wherein said metal powder is a magnetic alloy powder.

11. The laminated composite structure according to claim 9 wherein said metal powder is a non-magnetic alloy powder.

12. A method for manufacturing a laminated composite structure, comprising the steps of:

assembling in a cavity alternating layers of metal powder particles and an inorganic bonding media, said inorganic bonding media selected from at least one of the group of powders consisting of a ceramic, glass, and glass-ceramic; and

,

applying heat to said alternating layers until the particles of each said layer of said metal powder is sintered into a contiguous metallic layer, each said layer of said inorganic bonding media is sintered, and said alternating sintered layers are bonded into said laminated composite structure by the layers of sintered inorganic bonding media to one another to form a strong laminated composite structure.

13. A laminated composite structure comprised of:

alternating layers of metal powder particles and an inorganic bonding media selected from at least one of the group of powders consisting of a ceramic, glass, and glass-ceramic;

the metal powder particles sintered together and forming a contiguous metallic layer which is bonded into said laminated composite structure by the layers of sintered inorganic bonding media to form a strong composite structure.