Morphology and Microstructure of Sputtered Superalloy Coating

The morphology and microstructure of magnetron sputtered coating of superalloy K38G on cast al-loy K38G have been investigated by means of SEM, TEM and XRD. The results indicate that thesputtered coating is identical to the substrate in chemical composition but it is composed only of γphase without γ’. The sputtered superalloy coating presents columnar structure and the grain size isin the range of 20-100 nm. There are a great number of planar defects such as stacking faults andmicrotwins in the coating. The morphology and microstructure of the sputtered coating may haveclose relation to the remarkable increase of oxidation resistance of the coating.