Abstract: Disclosed is an improved apparatus for depositing a coating on the internal surfaces of hollow articles by gas phase deposition. The apparatus typically includes a sheet metal enclosure having a manifold member which defines a first and second chamber therein. The first chamber is adapted to contain a powder mixture for generating a coating gas whereas the second chamber is adapted to house the articles to be coated. The manifold member includes hollow tubes or other connector means extending therethrough to connect the interior of the articles in gas flow relation to the first chamber where the coating gas is generated. A source external of the enclosure supplies carrier gas to the first chamber at a controlled flow rate via tube means. The carrier gas transports the coating gas generated in the first chamber through the manifold tubes and then into the internal passages of the article to effect deposition.

Abstract: A gas phase aluminizing process for alloys based on Group VI B and VIII metals such as chromium, iron, cobalt and nickel is disclosed. The process is particularly useful in the coating of internal passages of complex high temperature gas turbine hardware such as blades and vanes, where it has been found that the complex aluminum halide activators used herein have a "throwing power" greater than was heretofore obtained with the conventional halide activators such as ammonium chloride in the gas phase process.