Apparatus and method of sintering elements by infrared heating

• US 6,200,523 B1
• Filed: 09/30/1999
• Issued: 03/13/2001
• Est. Priority Date: 10/01/1998
• Status: Expired due to Fees

• Current Assignee: USF Filtration and Separations Group, Inc. (Siemens AG)
• Original Assignee: USF Filtration and Separations Group, Inc. (Siemens AG)
• Inventors: McGrath, James A., Li, Tao, Quick, Nathaniel R., Malanga, Robert, Liberman, Michael, Sobolevsky, Alexander
• Primary Examiner(s): Jenkins, Daniel J.
• Application Number:
  US09/408,748
• Time in Patent Office: 530 Days
• Field of Search: 419/2, 419/4, 419/48
• US Class Current: 419/2
• CPC Class Codes: B22F 2202/11 Use of irradiation
• CPC Class Codes: B22F 2999/00 Aspects linked to processes or compositions used in powder metallurgy
• CPC Class Codes: B22F 3/002 Manufacture of articles essentially made from metallic fibres
• CPC Class Codes: B22F 3/14 simultaneously
• CPC Class Codes: B22F 3/18 by using pressure rollers
• CPC Class Codes: C22C 47/14 by powder metallurgy, i.e. by processing mixtures of metal powder and fibres or filaments

Abstract

An apparatus and a method is disclosed for sintering a matrix of elements such as fibers or particles by infrared heating. A multiplicity of the elements are arranged into a matrix of substantially randomly oriented elements to form a web. The web is irradiated with infrared energy for a period of time sufficient to sinter bond each of the elements to adjacent elements of the matrix randomly oriented elements.

Claims

1. The method of sintering a web of elements, comprising:

simultaneously compressing and irradiating the web containing elements with infrared energy for a period of time sufficient to sinter bond each of the elements to adjacent elements within a matrix of randomly oriented elements.

2. The method of sintering a web of elements as set forth in claim 1, wherein each of the elements of the matrix of randomly oriented elements is a metallic fiber.

3. The method of sintering a web of elements as set forth in claim 1, wherein each of the elements of the matrix of randomly oriented elements is a stainless steel fiber.

4. The method of sintering a web of elements as set forth in claim 1, wherein the elements of the matrix of randomly oriented elements comprises a plurality of first metallic fibers and a plurality of second metallic fibers.

5. The method of sintering a web of elements as set forth in claim 1, wherein the matrix of randomly oriented elements comprises a composite of a plurality of first elements and a plurality of second elements.

6. The method of sintering a web of elements as set forth in claim 1, wherein the matrix of randomly oriented elements comprises a composite of a plurality of first elements and a plurality of second elements;

and

each of said plurality of first elements being a metallic fiber and each of said second elements being a non-metallic particle.

7. The method of sintering a web of elements as set forth in claim 1, wherein the matrix of randomly oriented elements comprises a plurality of metallic elements and a plurality of non-metallic elements;

and

said plurality of metallic elements forming the matrix of the randomly oriented elements for entrapping said plurality of non-metallic elements therein.

8. The method of sintering a web of elements as set forth in claim 1, wherein the matrix of randomly oriented elements comprises a plurality of metallic elements and a plurality of non-metallic elements;

and

said plurality of metallic elements forming the matrix of the randomly oriented elements disposed on opposed sides of said plurality of non-metallic elements.

9. The method of sintering a web of elements as set forth in claim 1, wherein the matrix of randomly oriented elements comprises a plurality of metallic elements and a plurality of non-metallic elements;

and

the step of compressing and irradiating the web includes irradiating the web with infrared radiation having a wavelength for preferentially heating said plurality of metallic elements relative to said plurality of non-metallic elements.

10. The method of sintering a web of elements as set forth in claim 1, wherein the step of irradiating the web includes irradiating the web with infrared radiation having a wavelength greater than 700 nm angstroms.

11. The method of sintering a web of elements as set forth in claim 1, wherein the step of irradiating the web includes monitoring the temperature of the web;

and

controlling the output of the infrared radiation for irradiating the web in accordance with a predetermined standard.

12. The method of sintering a web of elements as set forth in claim 1, wherein the step of irradiating the web includes monitoring the temperature of the web;

and

controlling the output of the infrared radiation for irradiating the web in accordance with the Arrhenius formula.

13. The method of sintering a web of elements as set forth in claim 1, wherein the step of irradiating the web includes simultaneously irradiating the web from opposed first and second sides of the web.

14. The method of sintering a web of elements as set forth in claim 1, wherein the step of irradiating the web includes moving the web past the source of infrared radiation.

15. The method of sintering a web of elements as set forth in claim 1, wherein the step of irradiating the web includes irradiating the web in a vacuum.

16. The method of sintering a web of elements as set forth in claim 1, wherein the step of irradiating the web includes irradiating the web in a reactive atmosphere.

17. The method of sintering a web of elements as set forth in claim 1, wherein the step of irradiating the web includes irradiating the web in a non-reactive atmosphere.

18. The method of sintering a web of elements as set forth in claim 1, wherein the step of irradiating the web includes irradiating the web in a hydrogen atmosphere.

24. The method of forming a sintered web of fibers as set forth in claim 18, wherein the step of irradiating the web includes irradiating the web in a vacuum.

29. The method of sintering a web of elements as set forth in claim 1, including the step of compressing the web prior to irradiating the web with infrared energy.

19. The method of forming a sintered web of fibers, comprising:

arranging the fibers into a matrix randomly oriented fibers to form a web;

simultaneously compressing and irradiating the web with infrared energy for a period of time sufficient to sinter bond each of the fibers to adjacent fibers within the matrix randomly oriented fibers.

20. The method of forming a sintered web of fibers as set forth in claim 19, wherein the step of simultaneously compressing and irradiating the web includes rolling the web between a first and a second roller transparent to infrared energy for at least partially compressing the web and irradiating the web through the first and second transparent rollers onto opposed first and second sides of the web.

21. The method of forming a sintered web of fibers as set forth in claim 19, wherein the step of simultaneously compressing and irradiating the web includes compressing the web between a first and a second compression sheet transparent to infrared energy for at least partially compressing the web and irradiating the web through the first and second compression sheets onto opposed first and second sides of the web.

22. The method of forming a sintered web of fibers as set forth in claim 19, wherein the step of simultaneously compressing and irradiating the web includes compressing the web between a first and a second roller transparent to infrared energy for at least partially compressing the web and irradiating the web through the first and second rollers from a source of infrared energy positioned internal the first and second rollers.

23. The method of forming a sintered web of fibers as set forth in claim 19, wherein the step of compressing and irradiating the web includes compressing the web between a first and a second infrared transparent material for at least partially compressing the web;

and

irradiating the web through the first and second infrared transparent materials from a source of radiation positioned on opposed sides of the first and second infrared transparent materials.

25. The method of forming a sintered web of fibers as set forth in claim 19, wherein the step of irradiating the web includes irradiating the web in a reactive atmosphere.

26. The method of forming a sintered web of fibers as set forth in claim 19, wherein the step of irradiating the web includes irradiating the web in a non-reactive atmosphere.

27. The method of forming a sintered web of fibers as set forth in claim 19, wherein the step of irradiating the web includes irradiating the web in a hydrogen atmosphere.

28. The method of sintering a web of elements, comprising:

compressing the web with a compression material transparent to infrared energy; and

simultaneously irradiating the web with infrared energy passing through the compression material transparent energy for a period of time sufficient to sinter bond each of the elements to adjacent elements within the web.