Method for imaging inclusions in investment castings

A method for real time detection of inclusions in a metal or metal alloy article, comprising:

• forming an aqueous or non-aqueous facecoat slurry comprising an inclusion imaging agent;
• 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;
• serially applying plural backup layers to the pattern to form a mold for investment casting;
• casting a metal article using the mold;
• and
• analyzing the article for inclusions using real time N-ray analysis.

A method for real-time detection of inclusions in a titanium or titanium alloy article produced by investment casting, comprising:

• forming an aqueous or non-aqueous investment casting facecoat slurry comprising an intimate mixture of a mold-forming material selected from the group consisting of yttria, zirconia, alumina, calcia, silica, zircon, titania, tungsten, physical mixtures thereof, and chemical mixtures thereof, 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 lithium, boron, neodymium, samarium, europium, gadolinium, dysprosium, holmium, erbium, ytterbium, 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 real time 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 real time N-ray analysis.

A method for detecting inclusions in investment castings, comprising:

• placing a solution of at least one imaging agent inside a cavity of an investment casting mold;
• 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.

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 solution of at least one imaging agent comprising a material selected from the group consisting of lithium, boron, neodymium, indium, samarium, europium, gadolinium, dysprosium, holmium, erbium, ytterbium, 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
• analyzing the article for inclusions by N-ray imaging.