United Technologies Corporation

Neal P Anderson

Anthony F Giamei

Richard W Salkeld

Nicholas E Ulion

Raymond W Vine

Richard S Mullin

Charles Stanley Giggins, Jr

Leo A Riendeau

A yttria strengthened ceria material is disclosed. The addition of a small amount of yttria (for example 0.5%) significantly strengthens the ceria. The yttria modified ceria is useful as a thermal barrier coating.

Ceramic material and insulating coating made thereof

An improved thermal barrier coating system is described. A key feature of the invention is the presence of a thin, adherent aluminum oxide scale on the surface of the substrate. An oxide stabilized ceramic coating is present on the surface of the scale. Preferably, the ceramic coating has a columnar grain structure.

Advanced thermal barrier coated superalloy components

A method for applying ceramic coatings using electron beam--physical vapor deposition techniques is described. The method includes the step of introducing the anionic constituent of the ceramic into a coating chamber and confining the anionic constituent about the component to be coated during the coating cycle.

EB-PVD method for applying ceramic coatings

During conventional directional solidification of a single crystal article having a large overhanging flange lying along its length, crystal nucleation defects and shrinkage occur in the flange. To form articles without such defects, the part is cast so that the solidification front moves transverse to the length of the article, and essentially parallel to the flange surfaces where the defects tend to occur. The solidification front is initiated at a seed crystal oriented to produce the desired crystal structure in the cast article. Dendritic effects produce somewhat different properties in articles cast in accord with the invention, compared to those cast with prior art techniques.

Transverse directional solidification of metal single crystal articles

A method of epitaxially casting single crystal metal articles in molds, which comprises causing the solidification interface velocity vector to rotate through at least 90 degrees, preferably 180-540 degrees, about the axis of overall directional solidification growth. In addition, a mold section has a small passageway configured to prevent line of sight communication between the portion where the seed is contained and the article portion of the mold. Preferably, the passageway is shaped like a helix of 0.8-1.5 turns. A second seed can be formed in the mold of an article made from a first seed, and used to make a second casting. The invention reduces the normal increase in crystallographic variability which would otherwise be associated with such practice.

Casting a metal single crystal article using a seed crystal and a helix

In the manufacture of a single crystal article, by the directional solidification of a metal in a ceramic mold the melt-back of a seed crystal is controlled to provide high casting yield. The melt-back, measured as a fraction of the original length of the seed, is preferably between 25-75%, more preferably between 33-67%. Diametrical clearance between the seed and mold is also closely controlled, between 0.06-0.25 mm, to eliminate extraneous grain nucleation.

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South Windsor, CT, United States of America

Neal P Anderson