Wear mechanisms and in-service surface modifications of a Stellite 6B Co-Cr alloy

► In-service wear of Stellite large-scale components analysed by FIB-TEM methods. ► Grid nanoindentation method gives the hardness distribution of each phase. ► Results show significant surface modifications during in-service wear. ► Nano-crystalline hardened layer and tribo-film detected by TEM analysis. ► Wear is strongly enhanced by the presence of SiO2 and steel contaminations in the field environment.