Microstructural Investigation and Determining the Optimal Conditions for Nondestructive Testing of Inconel 738LC Superalloy Gas Turbine Blade

• Published in: Journal of failure analysis and prevention 2021, Vol.21 (4), p.1203-1211
• Main Authors: Rayatpour, Masumeh, Lalegani, Zahra
• Format: Article
• Language: English
• Subjects: Characterization and Evaluation of Materials; Chemistry and Materials Science; Classical Mechanics; Corrosion and Coatings; Diamond polishing; Diamonds; Etching; Gas turbine engines; Gas turbines; Materials Science; Mechanical polishing; Microstructure; Nondestructive testing; Quality Control; Reliability; Replication; Safety and Risk; Sanding; Solid Mechanics; Superalloys; Tools and Techniques; Tribology; Turbine blades
• ISSN: 1547-7029; 1728-5674; 1864-1245
• DOI: 10.1007/s11668-021-01203-w

The optimal conditions for nondestructive testing replication of an IN738LC gas turbine blade have determined. Elcoat 37 coating on IN738LC gas turbine blade has been removed by sanding and the use of corrosive solutions. Polishing and etching processes have been done mechanically and electrically. The mechanical polishing process has been done with felt polishing pad and diamond paste. Also, electrically, and continuous polishing and etching processes have been done by electropolishing machine. Various solutions in different times and voltages have been used to polishing and etching, and their resultant microstructural images has been investigated. The microstructure of replica samples has been studied by SEM. The results showed that the microstructure obtained from the solution 10% HClO 4 + H 2 O has a good condition for measuring γ ′ particles size. Eventually, the optimal conditions for replication process of IN738LC superalloy have been extracted.