IP Library Granted Patent US 6,890,971
Granted Patent B2
US 6,890,971 · App. 10/189,654 · Granted May 10, 2005

Method for making radiation absorbing material (RAM) and devices including same

Assignee: Steward Advanced Materials, Inc.
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Quick Facts
Patent No.
US 6,890,971
App. No.
10/189,654
Granted
May 10, 2005
Kind
B2
Abstract

A method for making a radiation absorbing material (RAM) coating may include providing an iron-silicon alloy powder, forming the iron-silicon alloy powder into flakes, and passivating the flakes. The method may further include selecting passivated flakes having a desired size, and combining the selected passivated flakes with a carrier to provide the RAM coating. The coating may be applied to a substrate to impart the radiation absorbing property thereto.

Claims (53)

1. A method for making a radiation absorbing material (RAM) coating comprising:

providing an iron-silicon alloy powder;

forming the iron-silicon alloy powder into flakes;

passivating the flakes;

selecting passivated flakes having a desired size; and

combining the selected passivated flakes with a carrier to provide the RAM coating.

2. The method of claim 1 wherein the iron-silicon alloy powder comprises melt sprayed iron-silicon alloy powder.

3. The method of claim 1 wherein the iron-silicon alloy powder comprises diffused iron-silicon alloy powder.

4. The method of claim 1 wherein forming comprises impact milling the iron-silicon alloy powder.

5. The method of claim 1 wherein forming comprises grinding the iron-silicon alloy powder using a dry attritor.

6. The method of claim 1 wherein forming comprises wet milling the iron-silicon alloy powder in the presence of a solvent.

7. The method of claim 6 wherein the solvent comprises heptane.

8. The method of claim 6 further comprising removing solvent prior to passivating.

9. The method of claim 1 wherein selecting comprises:

deagglomerating the passivated alloy flakes; and

screening the deagglomerated flakes to obtain flakes having the desired size.

10. The method of claim 1 wherein the desired size is a maximum dimension of less than about 60 microns.

11. The method of claim 1 wherein passivating comprises exposing the flakes to an oxygen containing ambient at a temperature of less than about 700° C.

12. The method of claim 1 wherein passivating comprises passivating the flakes for less than about 24 hours.

13. The method of claim 1 wherein the carrier comprises at least one of an organic material, a dielectric material, an electrically conductive material, a magnetic material, and an elastomeric material.

14. The method of claim 1 wherein the iron-silicon alloy powder comprises less than about 25% silicon by weight.

15. The method of claim 1 wherein combining comprises combining the selected passivated flakes and passivated, generally spherical iron-silicon alloy particles with the carrier to provide the RAM coating.

16. A method for making a radiation absorbing material (RAM) coating comprising:

providing an iron-silicon alloy powder;

wet grinding the iron-silicon alloy powder into flakes in the presence of a solvent;

passivating the flakes;

deagglomerating the passivated alloy flakes;

screening the deagglomerated flakes to obtain flakes having a desired size; and

combining the screened passivated flakes with a carrier to provide the RAM coating.

17. The method of claim 16 wherein the iron-silicon alloy powder comprises melt sprayed iron-silicon alloy powder.

18. The method of claim 16 wherein the solvent comprises heptane.

19. The method of claim 16 further comprising removing solvent prior to passivating.

20. The method of claim 16 wherein the desired size is a maximum dimension of less than about 60 microns.

21. The method of claim 16 wherein passivating comprises exposing the flakes to an oxygen containing ambient at a temperature of less than about 700° C.

22. The method of claim 16 wherein passivating comprises passivating the flakes for less than about 24 hours.

23. The method of claim 16 wherein the carrier comprises at least one of an organic material, a dielectric material, an electrically conductive material, a magnetic material, and an elastomeric material.

24. A method for making a radiation absorbing material (RAM) comprising:

providing an iron-silicon alloy powder;

forming the iron-silicon alloy powder into flakes;

passivating the flakes; and

selecting passivated flakes having a desired size.

25. The method of claim 24 wherein the iron-silicon alloy powder comprises melt sprayed iron-silicon alloy powder.

26. The method of claim 24 wherein forming comprises impact milling the iron-silicon alloy powder.

27. The method of claim 24 wherein forming comprises grinding the iron-silicon alloy powder using a dry attritor.

28. The method of claim 24 wherein forming comprises wet milling the iron-silicon alloy powder in the presence of a solvent.

29. The method of claim 28 wherein the solvent comprises heptane.

30. The method of claim 28 further comprising removing solvent prior to passivating.

31. The method of claim 24 wherein selecting comprises:

deagglomerating the passivated alloy flakes; and

screening the deagglomerated flakes to obtain flakes having the desired size.

32. The method of claim 24 wherein the desired size is a maximum dimension of less than about 60 microns.

33. The method of claim 24 wherein passivating comprises exposing the flakes to an oxygen containing ambient at a temperature of less than about 700° C.

34. The method of claim 24 wherein passivating comprises passivating the flakes for less than about 24 hours.

Assignments (7)
RELEASE OF SECURITY INTEREST Recorded Jun 17, 2021
From: FIDUS MEZZANINE CAPITAL II, L.P.
To: STEWARD ADVANCED MATERIALS LLC
Reel/Frame 056577/0179 →
CORRECTIVE ASSIGNMENT TO CORRECT THE LISTING OF NON-PERTINENT DOCUMENTS PREVIOUSLY RECORDED ON REEL 037026 FRAME 0347. ASSIGNOR(S) HEREBY CONFIRMS THE SECURITY INTEREST IN PATENT NO. 6890971. Recorded Jan 4, 2016
From: STEWARD ADVANCED MATERIALS LLC
To: BANK OF AMERICA, N.A.
Reel/Frame 037415/0389 →
SECURITY INTEREST Recorded Nov 12, 2015
From: STEWARD ADVANCED MATERIALS LLC
To: FIDUS MEZZANINE CAPITAL II, L.P.
Reel/Frame 037024/0064 →
SECURITY INTEREST Recorded Nov 12, 2015
From: STEWARD ADVANCED MATERIALS LLC
To: BANK OF AMERICA, N.A.
Reel/Frame 037026/0347 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Nov 12, 2015
From: STEWARD ADVANCED MATERIALS, INC.
To: STEWARD ADVANCED MATERIALS LLC
Reel/Frame 037023/0816 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jan 13, 2005
From: STEWARD, INC.
To: STEWARD ADVANCED MATERIALS, INC.
Reel/Frame 016148/0515 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jul 3, 2002
From: PARIS, HENRY G.; SMITH, DANNY R.; SMITH, SCOTT F.
To: STEWARD, INC.
Reel/Frame 013087/0486 →
Continuity (2)
Provisional Application 6030276800 · Jul 3, 2001
Related Publication 20030008131A1 · Jan 9, 2003