Refractory crucibles and molds for containing reactive molten metals and salts

• US 6,604,941 B2
• Filed: 06/26/2001
• Issued: 08/12/2003
• Est. Priority Date: 03/29/1996
• Status: Expired due to Fees

• Current Assignee: Garth W. Billings
• Original Assignee: Integrated Thermal Sciences, Inc.
• Inventors: Billings, Garth W.
• Primary Examiner(s): TURNER, ARCHENE A
• Application Number:
  US09/892,239
• Publication Number:
  US 20010033950A1
• Time in Patent Office: 777 Days
• Field of Search: 428/699, 428/698, 428/701, 428/702, 428/408, 428/472, 428/332, 432/264, 432/265, 432/285
• US Class Current: 432/265
• CPC Class Codes: B22C 1/00 Compositions of refractory mould or core materials; Grain structures thereof refractory materials in general C04B35/00; Chemical or physical features in the formation or manufacture of moulds
• CPC Class Codes: B22C 3/00 Selection of compositions for coating the surfaces of moulds, cores, or patterns
• CPC Class Codes: C04B 35/58007 based on refractory metal nitrides
• CPC Class Codes: C04B 35/58028 based on zirconium or hafnium nitrides
• CPC Class Codes: C23C 26/00 Coating not provided for in groups C23C2/00 - C23C24/00
• CPC Class Codes: C23C 30/00 Coating with metallic material characterised only by the composition of the metallic material, i.e. not characterised by the coating process C23C26/00, C23C28/00 take precedence
• CPC Class Codes: Y10T 428/26 Web or sheet containing structurally defined element or component, the element or component having a specified physical dimension
• CPC Class Codes: Y10T 428/30 Self-sustaining carbon mass or layer with impregnant or other layer

Abstract

Refractory ceramics and composite materials consisting of nitrides, mixed nitrides and oxides, and oxynitrides of Group IV metals Hf, Zr, Ti, and Group III metals Sc, Y, and lanthanides La through Lu, are used to form refractory articles, or as coatings for refractory articles. These materials and articles have high resistance to molten metals, molten salts, erosion, and high temperature corrosive environments, and can be engineered to have desirable thermal and electrical properties. In particular the articles are crucibles, molds, containment vessels, and spray nozzles, and most particularly these articles are made of or coated with the Hf compounds.

Claims

1. An article of manufacture comprising a molten metal processing or molten salt processing article selected from a refractory crucible, mold, containment vessel, or molten metal spray nozzle, wherein the article further comprises a shaped body having at least a molten metal contacting and resistant or molten salt contacting and resistant layer formed of a refractory material selected from a nitride, mixed nitride and oxide, or oxynitride of a Group IV metal selected from Hf and Zr;

a nitride, mixed nitride and oxide, or oxynitride of a Group III metal selected from Sc, Y, and the lanthanides La through Lu; and

combinations or reaction products of a nitride, mixed nitride and oxide, or oxynitride of a Group IV metal selected from Hf, Zr, and Ti, and a nitride, mixed nitride and oxide, or oxynitride of a Group III metal selected from Sc, Y, and the lanthanides La through Lu.

2. The article of claim 1 wherein the entire shaped body is formed of the refractory material.

3. The article of claim 1 wherein the shaped body comprises:

a central portion formed of a metal, ceramic, or graphite;

an outer coating on the central portion and formed of the refractory material.

4. The article of claim 3 wherein the central portion is formed of metal selected from Ta, W, Nb, Mo, or alloys of these metals.

5. The article of claim 3 further comprising an intermediate functional layer between the central portion and the outer coating.

6. The article of claim 1 wherein the Group IV metal is Hf.

7. The article of claim 1 wherein the refractory material is selected from a nitride, mixed nitride and oxide, or oxynitride of a Group IV metal selected from Hf and Zr, and has a thickness of at least about 25 micrometers.

8. The article of claim 1 wherein the refractory material is selected from a nitride, mixed nitride and oxide, or oxynitride of a Group III metal selected from Sc, Y, and the lanthanides La through Lu.

9. The article of claim 1 wherein the refractory material is selected from a Group III-Group IV combination or reaction product of a nitride, mixed nitride and oxide, or oxynitride of a Group IV metal selected from Hf, Zr, and Ti, and a nitride, mixed nitride and oxide, or oxynitride of a Group III metal selected from Sc, Y, and the lanthanides La through Lu.

10. An article of manufacture comprising a molten metal processing or molten salt processing article selected from a refractory crucible, mold, containment vessel, or molten metal spray nozzle, wherein the article further comprises a shaped body having at least a molten metal contacting and resistant or molten salt contacting and resistant layer formed of a hafnium nitride, the hafnium nitride having a thickness of at least about 25 micrometers.

11. The article of claim 10 wherein the entire shaped body is formed of the hafnium nitride.

12. The article of claim 10 wherein the shaped body comprises:

a central portion formed of a metal, ceramic, or graphite;

an outer coating on the central portion and formed of the hafnium nitride.

13. The article of claim 12 wherein the central portion is formed of metal selected from Ta, W, Nb, Mo, or alloys of these metals.

14. The article of claim 12 further comprising an intermediate functional layer between the central portion and the outer coating.

15. The article of claim 10 wherein the hafnium nitride is mixed with hafnium oxide.

16. The article of claim 10 wherein the hafnium nitride is a hafnium oxynitride.

17. The article of claim 10 wherein the hafnium nitride is combined with or reacted with a nitride, mixed nitride and oxide, or oxynitride of a Group III metal selected from Sc, Y, and the lanthanides La through Lu.

18. The article of claim 12 comprising a tantalum crucible with a hafnium nitride coating.

19. An article of manufacture comprising a molten metal processing or molten salt processing article selected from a refractory crucible, mold, containment vessel, or molten metal spray nozzle, wherein the article further comprises a shaped body having at least a molten metal contacting and resistant or molten salt contacting and resistant layer formed of a refractory material selected from a nitride, mixed nitride and oxide, or oxynitride of a Group IV metal selected from Hf, Zr, and Ti, having a thickness of at least about 25 micrometers;

and combinations or reaction products of a nitride, mixed nitride and oxide, or oxynitride of a Group IV metal selected from Hf, Zr, and Ti, and a nitride, mixed nitride and oxide, or oxynitride of a Group III metal selected from Sc, Y, and the lanthanides La through Lu.

20. The article of claim 19 wherein the group IV metal is Hf.