Abstract
hardmetal exhibits high corrosion susceptibility in aqueous solutions, related to complex microscale reaction mechanisms. This paper presents developed methods to characterize the local distribution of surface reactions difficult to assess by conventional electrochemical methods. Laterally resolved electrochemical potential distributions measured using scanning Kelvin probe force microscopy (SKPFM) under controlled humidity identified the more noble nature of and the microscale galvanic coupling with the Co areas acting as anodes. Inductively coupled plasma mass spectrometry (ICP-MS) element analysis, carried out using an online flow cell, provided simultaneous, time-resolved detection and quantitative concentration measurement of the dissolved elements. W ions in solution at the open-circuit potential indicated chemical dissolution due to the pH increase on the cathodes in addition to electrochemical anodic Co dissolution. Various mechanisms attributed to homogeneous dissolution of microscale phases or dissolution transients related to localized corrosion attack are identified. X-ray photoelectron spectroscopy (XPS) revealed a carbon-rich surface layer on the grains supporting a mechanism of selective W dissolution. These different techniques provided information on the microscale reactions on surfaces in aqueous solution and allowed construction of a comprehensive model.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
