Criteria of assessment of powders provided to spray by the APS method for new and conventional layers type TBC

Purpose: Verification of up-to-now use of conventional powders, provided to spray by the APS method for layers type TBC and its possible adaptation to layers of new types, which are based on new ceramic compounds, sprayed on conventional high temperature creep resisting alloys. New types of used ceramic powders are so called pyrochlores of the RE2Zr2O7 general formula. Design/methodology/approach: A scope of investigations comprised review of up-to-now used criteria of assessment and verification of them on powders of new types. Investigations of chemical composition were realized, in consideration of carbon and sulphur contents and gas oxygen and nitrogen contents. Investigations on sizes of powders by a sieve method and investigations on surface morphology were carried out. Assessment of microstructure, considering homogeneity in chemical composition and porosity, was carried out. Assessment of phase contents of exemplary powders was carried out. Findings: The carried out analysis enabled to compare criteria of assessment for two types of powders, provided to be sprayed by the APS method. It was stated that up-to-now used criteria of assessment of powders were correct also for materials of new types. Research limitations/implications: The carried out investigations suggest a necessity to verify results also on an example of another type of new powders. Practical implications: The got results reveal a possibility to use up-to-now procedures in assessment of powders for materials of a new type, completed with characteristics of physical and mechanical properties. Originality/value: Information concerning basic principles in assessment of properties microstructure of powders of a new type is an original value, presented in the article.