An Automated Test Platform for High-Throughput Micro-Electrochemical Characterization of Metallic Materials and Its Application on a Fe–Cr–Ni Combinatorial Materials Chip

Abstract

An automated platform that can perform standard electrochemical tests at the micro-scale will greatly facilitate the electrochemical property screening of a combinatorial materials chip. Here we report an automated test platform for high-throughput characterization of metallic materials’ local electrochemical properties. It integrates four components, including a micro-electrochemical cell, an automatic liquid refresh system, a programmed scanning automated XYZ stage, and a control system. The high-throughput test cell array is constructed using capillary and lithography techniques. The automation is achieved by a Lab View program that can control all the components. We validated the system reliability by characterizing the surface electrochemical activity of the Fe-based alloy in a Fe–Cr–Ni combinatorial materials chip. Combining electron probe micro-analysis, X-ray diffraction, and the above local electrochemical tests, the relationship between composition, crystal structure, and the electrochemical properties of the Fe-based alloy has been established and discussed. The results demonstrate that this is a highly promising technique for high-efficiency data collection for database construction and corrosion-resistant material design.

High-Throughput Electrochemistry to Study Materials Degradation in Extreme Environments

“…For instance, all the systems developed via the HTP synthesis techniques detailed above will suffer from galvanic corrosion if immersed in the same conductive electrolyte. In addition, if the system is only homogeneous and stable across a small length scale (such as in the case of compositional gradients), monitoring the corrosion process in situ requires local techniques, such that microelectrochemical probe development is necessary . On the other hand, one could also study the effect of electrolyte composition on alloy corrosion, but this requires the manufacturing of many independent corrosion cells and a proper sampling of electrolyte composition to vary redox potential, basicity, impurity content, etc.…”

“…In addition, if the system is only homogeneous and stable across a small length scale (such as in the case of compositional gradients), monitoring the corrosion process in situ requires local techniques, such that microelectrochemical probe development is necessary. 16 On the other hand, one could also study the effect of electrolyte composition on alloy corrosion, but this requires the manufacturing of many independent corrosion cells and a proper sampling of electrolyte composition to vary redox potential, basicity, impurity content, etc. Thus, we will use "HTP" to identify any methods that are significantly increasing the throughput relative to conventional approaches, where a single alloy is studied in a single electrolyte.…”

Small-Area Techniques for Micro- and Nanoelectrochemical Characterization: A Review

“…In this arrangement, most of the shortcomings of the MCC technique and the traditional PMT have been improved. 72 In comparison to the typical capillary microelectrochemical cell (Figure 6D), the higher electrolyte volume/WE area ratio reduces the effect of local composition variation and avoids the blockage risk. Moreover, the distance between the WE and the CE can be shortened as much as possible to reduce the ohmic resistance.…”

“…A multifabrication of the photoresist−microelectrode array cell can be implemented to improve the spatial resolution, if necessary, as detailed in Figure 6E. 72 In addition to the advantages listed above, this microelectrochemical test system can realize automatic measurement When comparing the images of different materials (i.e., 309L in Figure 7A, SA508 in Figure 7B, and X70 in Figure 7C) before (optical) and after (SEM) the EC test, there is no crevice corrosion, which indicates a good adherence between the photoresist and the substrate. The corrosion footprints (see Figure 7, panels A-ii, B-ii, and C-ii) of different materials showcase the accurate control of the WE dimension using this method.…”

“…By means of this method, the local electrochemical behavior of the fusion line in an SA508-309L dissimilar metal welded joint was investigated, 200 and a high-throughput microelectrochemical characterization has been carried out on an Fe−Cr−Ni combinatorial materials chip. 72 It is a powerful technique for high-throughput data collection that can perform the traditional electrochemical test, exhibiting extensive application prospects for local electrochemical analysis. Combining high-throughput characterization technology of material structure and composition (e.g., EBSD and EDS) and computer technology (e.g., machine learning, neural networks, and finite element simulation), a new strategy can be conducted for the in-depth study of metallic corrosion behavior, design of new alloys, and electrocatalytic materials screening.…”