Abstract: A coated article and method for producing the coated article are described. The article is provided with a coating system which provides protection against hot corrosion at moderate temperatures (1200.degree.-1700.degree. F.). An overlay coating based on a metal selected from the group consisting of iron, nickel or cobalt or mixtures thereof and containing chromium and optionally aluminum, yttrium and/or hafnium is applied to the article to be protected. A silicon rich surface zone is produced at the surface of the overlay coating. Methods including pack cementation and physical vapor deposition are described for producing the coating.

Abstract: A coated article and method for producing the coated article are described. The article is coated with a system which provides protection against oxidation and corrosion and which significantly reduces the substrate temperature. An MCrAlY layer is applied to the article to be protected and a columnar grain ceramic is applied by vapor deposition to the MCrAlY coated article. An alumina lyaer which exists between the MCrAlY layer and the columnar ceramic layer provides for the adherence of the columnar layer to the MCrAlY layer. An important feature of the invention is that the interface between the MCrAlY layer and the alumina layer has a low surface roughness and this greatly improves the columnar ceramic layer adherence.

Abstract: The process of making an ingot for use as a feed stock for a coating process in which the ingot is vaporized to produce the coating material; the ingot being made by forming a billet of the alloy minus the reactive element with a rod of the reactive element of the alloy extending centrally through the billet and then shaping the billet to ingot size, the cross-sectional area of the rod having the same relation of the remainder of the area of the billet as the percentage of the reactive element in the alloy.

Abstract: The process of making an ingot for use as a feed stock for a coating process in which the ingot is vaporized to produce the coating material; the ingot being made by forming a billet of the alloy minus the reactive element with a rod of the reactive element of the alloy extending centrally through the billet and then shaping the billet to ingot size, the cross-sectional area of the rod having the same relation of the remainder of the area of the billet as the percentage of the reactive element in the alloy.