Condition assessment of gas turbine blades and coatings

This paper brings out the metallurgical investigation that was carried out on discoloured low pressure turbine rotor blade (LPTR) for its platinum modified aluminium coating integrity and overheated high pressure turbine rotor blade (HPTR) for its blade material and coating integrity. LPTR blades were investigated as they were for the requirement of reuse. Heat tinting, EDS and XRD were carried out to present the harmonized inference that the coating was in good condition. HPTR blades were sectioned to study under SEM. Regions of platinum modified aluminide coating degradation and DS CM 247 LC base material cracking were observed which make the particular lot unusable.

► We examine the turbine blades non-destructively.
► We look at heat tinted surface, phases and elemental composition of the coating.
► Harmonized inference show that the coating was in good condition.
► We examine overheated blade by looking at their microstructures.
► We observe cracking and degradation.