Protection of Superalloys for Turbine Application

Formation of aluminide phases on electrodeposited nanocrystalline nickel

“…Some samples were etched in 1:1:1 solution of HNO 3 , H 2 SO 4 , and H 3 PO 4 1 followed by immersing in 1:1 solution of HNO 3 and H 3 COOH 2 . Then the cross section of coated specimens was characterized by means of optical microscopy (OM), scanning electron microscopy (SEM) equipped with energy dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD).…”

“…There are diverse methods to apply aluminide coatings on the surface of metals [4], among them; pack cementation is frequently used in practice [5]. In this technique, aluminum is transferred from the pack to the specimen surface in the form of aluminum halides [6].…”

Recent Advances of High Entropy Alloys: High Entropy Superalloys

“…The deposition of Al from a different external source and diffusing it into the base superalloy to for an external layer is called aluminide or diffusion coating. Bonding an oxidation-resistant alloy which is weak but highly effective on a superalloy to enable surface protection and stability is called overlay cladding, while ceramic barriers are ceramic coatings attached to the surface of a superalloy [89].…”

Advanced Gas Cooled Nuclear Reactor Materials Evaluation and Development Program: Topical report I, selection of candidate alloys. Volume 3. Selection of surface coating/substrate systems for screening creep and structural stability studies

“…Metalliding has not been used on a large scale as a coating technique for high temperature com- (11) ponents and will not be considered further in this review. Since the activity of the metal to be deposited is higher in the volatile compound than in the component to be coated, the compound decomposes on the surface of the component.…”