Surface preparation methodology for nanoindentation of high roughness coatings

Abstract

 This work presents a methodology for the preparation of the 
surface prior to nanoindentation tests that increases the 
precision of the results in rough surfaces. In applications where 
the maximum indentation size is dimensionally comparable 
with the specimen roughness, the accuracy and precision may 
be too poor. The developed methodology is focused on these 
cases.
The methodology has been developed for thin coatings that are 
harder than the substrate. It has been validated and applied on 
TiO2
 coatings deposited by PVD on Inconel® 718 and subjected 
to temperatures between 600 °C and 1100 °C, treatment 
that increases the specimen roughness. Modifying different 
parameters, it has been possible to analyse the improvement of 
the results due to the method and its uncertainty sources and 
to compare it with the usual nanoindentation technique