Metallographic preparation of the conventional and new TBC layers

Purpose: Verification of up-to-now used metallographic preparation of the TBC coating thermal barriers and adaptation of them to layers of new types, based on new ceramic compounds, sprayed on conventional high temperature creep resisting alloys by the APS method, is a purpose of this paper. New types of used ceramic powders are so called pyrochlores of a general formula RE2Zr2O7. Design/methodology/approach: A scope of investigations comprised realization of a process of preparation of metallographic micro-sections, beginning from a cutting moment, through mounting, grinding and polishing. A standard method of preparation of micro-sections, typical for conventional layers was used and microstructural observation, from a point of view of presence of artefacts of mechanical origin was carried out. Findings: The carried out analysis allowed to compare methods of preparation of micro-sections and principles of preparation, used to assess the conventional TBC layers and relation them to barrier layers of new types. The carried out investigations showed that up-to-now used methods and procedures for the TBC layers, got by usage of conventional powders, are sufficient for layers of new types. Research limitations/implications: The carried out investigations suggest a necessity to verify the got results in a case of the TBC layers, sprayed by use of powders of pyrochlore structure of another type. Practical implications: The got results show a possibility to use up-to-now metallographic procedures for the TBC layers of new types. Originality/value: Information, concerning basic principles of microstructural assessment of layers of new types, sprayed by the APS method on high temperature creep resisting alloys, is an original value.