|
7434 |
|
Friday, May 06, 2022, Hall G2 11:00 AM Characterization & Testing Methods I |
|
Utilization of short-time corrosion measurements with gel electrolytes for quality evaluation of thermal sprayed 316L coatings |
|
Maximilian Grimm* / Chemnitz University of Technology, Germany Pia Kutschmann / Materials and Surface Engineering Group, Institute of Materials Science and Engineering, Chemnitz University of Technology, Germany Christian Pluta/ JELN Imprägnierung GmbH, Germany Kerstin Ernst/ Putzier Oberflächentechnik GmbH, Germany Olga Schwabe/ Putzier Oberflächentechnik GmbH, Germany Thomas Lindner/ Materials and Surface Engineering Group, Institute of Materials Science and Engineering, Chemnitz University of Technology, Germany Thomas Lampke/ Materials and Surface Engineering Group, Institute of Materials Science and Engineering, Chemnitz University of Technology, Germany |
|
For the development of spraying processes, a complex microstructure analysis of the coating is usually necessary. Checking critical areas of a component is often only possible by means of destructive testing. In this work, the suitability of electrochemical properties such as corrosion current density is investigated in order to evaluate the quality of thermally sprayed 316L coatings with regard to their process-related microstructure. By using gel electrolytes, infiltration of the corrosive medium into the porous and micro-cracked structure characteristic of thermal sprayed coatings can be prevented. By using various spraying processes (APS, HVAF, HVOF) and parameters, 316L coatings with different microstructures were produced to study the relationships between process-typical microstructural effects and electrochemical corrosion properties. For this purpose, the gel electrolytes and a measuring cell based on the typical 3-electrode arrangement were developed. The microstructure of the 316L coatings was analyzed by SEM and EDS with regard to their porosity, oxide content, etc. The results clearly show that the current density-potential curves of the 316L coatings differ significantly depending on the spray process used and microstructure created. Even small differences within a coating can be detected as well. Electrochemical corrosion properties could therefore be suitable for evaluating the quality of thermal sprayed 316L coatings in a quasi-nondestructive manner. |