Instrumented sharp indentation is often employed formicromechanical investigation of thermal-spray coatings.However, rather complex dependenciesof measured values on indentation load have been reported. To verify the possible influence of sub-surface cracking,Vickers and Berkovich indentations onplasma-spray TiO2 were sectioned by FIB. Remarkable sub-surface cracking was found for indentations performed on the coating cross-section, even forrather low loads (1 N).Much less sub-surface cracking occurs when indenting the top surface, indicatingmaterial anisotropy. This preliminary investigationhighlights the need for thorough studies of sub-surface cracking during instrumented sharp indentation.
A FIB study of sharp indentation testing on plasma-sprayed TiO2 / Bolelli, Giovanni; Cannillo, Valeria; Lusvarghi, Luca; F., PIGHETTI MANTINI; Gualtieri, Enrico; C., Menozzi. - In: MATERIALS LETTERS. - ISSN 0167-577X. - STAMPA. - 62:10-11(2008), pp. 1557-1560. [10.1016/j.matlet.2007.09.022]