Claims
- 1. A method for determining whether a metal or metal alloy article has inclusions, comprising:
- providing a cast metal or metal alloy article made using a casting mold comprising an imaging agent which includes a material selected from the group consisting of boron, neodymium, samarium, europium, gadolinium, dysprosium, holmium, lutetium, iridium, physical mixtures thereof and chemical mixtures thereof, the imaging agent being used in amounts sufficient for imaging inclusions; and
- determining whether the article has inclusions by N-ray analysis.
- 2. The method according to claim 1 where the casting mold is an investment casting mold.
- 3. The method according to claim 2 where the investment casting mold includes an imaging agent distributed substantially uniformly throughout at least a facecoat.
- 4. The method according to claim 2 where the mold further includes at least one backup layer comprising an imaging agent.
- 5. The method according to claim 1 where the imaging agent is a metal salt, a metal oxide, an intermetallic, a boride, or mixtures thereof.
- 6. The method according to claim 1 where a linear attenuation coefficient of the article and a linear attenuation coefficient of the imaging agent are sufficiently different to allow N-ray imaging of the inclusion throughout the article.
- 7. The method according to claim 1 wherein the facecoat comprises substantially completely gadolinia as both the imaging agent and as a mold refractory material.
- 8. The method according to claim 1 where the imaging agent includes a material selected from the group consisting of dysprosium, samarium, gadolinium, physical mixtures thereof and chemical mixtures thereof.
- 9. A method for casting a metal or metal alloy article, comprising:
- providing a casting mold comprising an N-ray imaging agent which includes a material selected from the group consisting of boron, neodymium, samarium, europium, gadolinium, dysprosium, holmium, lutetium, iridium, physical mixtures thereof and chemical mixtures thereof;
- casting a metal or metal alloy article using the casting mold; and
- determining whether the article has inclusions by at least N-ray analysis.
- 10. The method according to claim 9 where determining whether the article has inclusions comprises analyzing N-ray images.
- 11. The method according to claim 9 where determining whether the article has inclusions comprises analyzing the article for inclusions by N-ray analysis.
- 12. A method for analyzing a cast metal or metal alloy article for inclusions, comprising:
- casting a metal or metal alloy article using a mold having a facecoat comprising an imaging agent distributed substantially uniformly throughout in amounts sufficient for imaging inclusions, the imaging agent including a material selected from the group consisting of boron, neodymium, samarium, europium, gadolinium, dysprosium, holmium, lutetium, iridium, physical mixtures thereof and chemical mixtures thereof; and
- analyzing the article for inclusions by N-ray analysis.
- 13. The method according to claim 12 where the mold is an investment casting mold, and the imaging agent is distributed substantially uniformly in at least a facecoat layer.
- 14. The method according to claim 12 where the step of analyzing further comprises X-ray analysis.
- 15. The method according to claim 13 where the mold further includes at least one backup layer comprising an imaging agent.
- 16. The method according to claim 12 where the article comprises a titanium or a titanium alloy and the facecoat further comprises a refractory material.
- 17. The method according to claim 16 where the refractory material is yttria, zirconia, alumina, calcia, silica, zircon titania, tungsten, physical mixtures thereof, and chemical mixtures thereof.
- 18. The method according to claim 16 where the refractory material is yttria or zirconia.
- 19. The method according to claim 18 where the imaging agent is gadolinia.
- 20. The method according to claim 12 where a facecoat slurry used to deposit the facecoat comprises from about 1 to about 100 weight percent imaging agent.
- 21. The method according to claim 12 where a facecoat slurry used to deposit the facecoat comprises from about 1 to about 65 weight percent imaging agent.
- 22. The method according to claim 12 where a facecoat slurry used to deposit the facecoat comprises from about 2 to about 25 weight percent imaging agent.
- 23. The method according to claim 12 where the facecoat comprises an intimate mixture of a refractory material and the imaging agent.
- 24. The method according to claim 12 where the facecoat comprises intimately mixed imaging agents.
- 25. The method according to claim 12 where the facecoat comprises intimately mixed refractory materials.
- 26. The method according to claim 12 where the article comprises titanium or a titanium alloy and the facecoat comprises yttria cocalcined with gadolinia.
- 27. The method according to claim 2 where the facecoat comprises a refractory material and plural imaging agents.
- 28. The method according to claim 27 where the refractory material is yttria and one of the plural imaging agents is gadolinia.
- 29. A method for analyzing a cast metal or metal alloy article for mold-derived inclusions, comprising:
- forming an aqueous or non-aqueous facecoat slurry comprising an inclusion imaging agent, the imaging agent including a material selected from the group consisting of boron, neodymium, samarium, europium, gadolinium, dysprosium, holmium, lutetium, iridium, physical mixtures thereof and chemical mixtures thereof;
- applying the facecoat slurry to a pattern to form a mold facecoat comprising the imaging agent distributed substantially uniformly throughout in amounts sufficient for imaging inclusions;
- forming an investment casting mold having the facecoat;
- casting a metal or metal alloy article using the mold; and
- analyzing the article for inclusions using N-ray analysis.
- 30. The method according to claim 29 where the step of analyzing further comprises X-ray analysis.
- 31. The method according to claim 29 where at least one of the backup layers includes an imaging agent.
- 32. The method according to claim 29 where the imaging agent is a metal salt, a metal oxide, an intermetallic, a boride, or mixtures thereof.
- 33. The method according to claim 29 where the article comprises a titanium or a titanium alloy and the facecoat further comprises a refractory material.
- 34. The method according to claim 33 where the refractory material is yttria.
- 35. The method according to claim 29 where a facecoat slurry used to deposit the facecoat comprises from about 1 to about 100 weight percent imaging agent.
- 36. The method according to claim 29 where a facecoat slurry used to deposit the facecoat comprises from about 2 to about 25 weight percent imaging agent.
- 37. The method according to claim 29 where a facecoat slurry used to deposit the facecoat comprises from about 2 to about 25 weight percent imaging agent.
- 38. The method according to claim 37 where the imaging agent is gadolinia.
- 39. The method according to claim 29 where the step of forming an aqueous or non-aqueous facecoat slurry first comprises forming an intimate mixture of a refractory material and the imaging agent and thereafter forming the slurry.
- 40. The method according to claim 39 where the article comprises titanium or a titanium alloy and the facecoat comprises yttria cocalcined with gadolinia.
- 41. The method according to claim 29 where the facecoat comprises a refractory material and plural imaging agents.
- 42. The method according to claim 41 where the refractory material is yttria and one of the plural imaging agents is gadolinia.
- 43. The method according to claim 29 where at least a portion of the metal or metal alloy article has a thickness of greater than about 2 inches.
- 44. The method according to claim 29 where the difference between a linear attenuation coefficient of the article and a linear attenuation coefficient of the imaging agent is sufficient to allow imaging of the inclusion throughout the article.
- 45. A method for analyzing a titanium or titanium alloy article produced by investment casting for inclusions, comprising:
- forming an aqueous or non-aqueous investment casting facecoat slurry comprising an intimate mixture of a mold-forming material and an imaging agent in an amount sufficient to allow imaging of inclusions in the article, the imaging agent including a material selected from the group consisting of boron, neodymium, samarium, europium, gadolinium,,dysprosium, holmium, lutetium, iridium, physical mixtures thereof and chemical mixtures thereof;
- applying the slurry to a pattern to form a mold facecoat comprising the intimate mixture of the mold-forming material and the imaging agent distributed substantially uniformly throughout in amounts sufficient for imaging inclusions wherein a linear attenuation coefficient of the article and a linear attenuation coefficient of the imaging agent are sufficiently different to allow imaging of the inclusion throughout the article by N-ray analysis;
- serially applying plural backup layers to the pattern and thereafter firing the pattern to form a mold for investment casting;
- casting a titanium or titanium alloy article using the mold; and
- analyzing the article for mold inclusions by N-ray analysis.
- 46. The method according to claim 45 where the step of analyzing further comprises X-ray analysis.
- 47. The method according to claim 45 where at least one backup layer also comprises an imaging agent.
- 48. The method according to claim 45 where the imaging agent is a metal salt, a metal oxide, an intermetallic, a boride, or mixtures thereof.
- 49. The method according to claim 45 where the mold-forming material is yttria and the imaging agent is gadolinia.
- 50. The method according to claim 49 where the facecoat comprises yttria cocalcined with gadolinia.
- 51. The method according to claim 45 where the facecoat comprises a refractory material and plural imaging agents.
- 52. The method according to claim 51 where the refractory material is yttria and one of the plural imaging agents is gadolinia.
- 53. A method for analyzing investment cast articles for inclusions, comprising:
- placing a solution of at least one imaging agent inside a cavity of an investment casting mold, the imaging agent including a material selected from the group consisting of boron, neodymium, samarium, europium, gadolinium, dysprosium, holmium, lutetium, iridium, physical mixtures thereof and chemical mixtures thereof;
- allowing the solution to remain in the cavity for a sufficient period of time to infiltrate at least the facecoat of the mold;
- removing the solution from the cavity;
- casting a metal or metal alloy article using the mold; and
- analyzing the article for mold inclusions by N-ray imaging.
- 54. The method according to claim 53 where the imaging agent comprises gadolinium.
- 55. The method according to claim 54 where the metal or metal alloy is titanium or a titanium alloy, and the facecoat comprises yttria.
- 56. The method according to claim 53 and further comprising analyzing the article for inclusions by X-ray imaging.
- 57. The method according to claim 53 where the solution comprises plural imaging agents.
- 58. A method for detecting inclusions in investment castings, comprising:
- forming an investment casting mold facecoat about a pattern;
- infiltrating at least a portion of the facecoat using an aqueous or non-aqueous composition comprising at least one imaging agent comprising a material selected from the group consisting of boron, neodymium, samarium, europium, gadolinium, dysprosium, holmium, lutetium, iridium, physical mixtures thereof and chemical mixtures thereof;
- casting a metal or metal alloy article using an investment casting mold having the facecoat; and
- detecting inclusions by N-ray imaging.
- 59. The method according to claim 58 and farther including the steps of:
- forming plural mold backup layers about the pattern; and
- infiltrating at least one of the plural mold backup layers with the solution of the imaging agent.
- 60. The method according to claim 59 and further including the steps of:
- forming plural mold backup layers about the pattern; and
- infiltrating the plural mold backup layers with the solution of the imaging agent.
- 61. The method according to claim 59 where the step of infiltrating comprises immersing at least a portion of the pattern having the facecoat into an aqueous or non-aqueous solution comprising the imaging agent for a period of time sufficient to infiltrate the facecoat with imaging agent.
CROSS REFERENCE TO RELATED APPLICATION
The present application claims priority from copending provisional application, No. 60/069,597, filed on Dec. 15, 1997, which is incorporated herein by reference.
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