The research activities are focused on studies of interfacial processes of metallic materials in electrolytes using advanced electrochemical techniques including spectroscopic and microscopic methods. Usually the materials studied have a high corrosion resistance, e.g., stainless steels, Ti and Al alloys, and surface coatings such as oxides and nitrides, etc. Besides aqueous corrosion of stainless steels and other alloys, biomaterial is one of the focuses; the study of health risks of using metallic materials is increasing. The main aims are: to investigate electrochemical processes occurring at electrode-electrolyte interfaces; to evaluate corrosion resistance of the materials in solutions; and to characterize electric and dielectric properties of the surface oxides/films. The following are short descriptions of recent and ongoing projects:
(1) In-situ study of localized corrosion of stainless steel and Al alloys - Localized corrosion can be triggered at narrow sites or defects on mm or nm scale. In this project, by using electrochemical AFM, scanning electrochemical microscopy and other local probes, localized corrosion of stainless steels and Al alloys, etc. is studied in situ in aggressive solutions, to study the role of inclusions, phase boundary and intermetallic particles on the localized corrosion resistance. The local approach leads to a deeper understanding of the mechanism of localized corrosion of the materials.
(2) Electrochemical behaviour and corrosion resistance of biomedical materials - Electrochemical behaviour, corrosion resistance and long-term stability of biomedical materials are essential for the performance and reliability of biomedical devices, e.g., pacemakers. In this project, electrochemical behaviour of biomedical materials in synthetic biological solutions, and the influence of surface roughness and porosity are investigated by different electrochemical techniques and surface analysis. Knowledge gained is used to optimize material design, improve its performance and evaluate long-term stability of the biomedical devices.
(3) Impedance study of oxide films at high temperatures - Electrical properties of oxide films depend on their defect structure and related to transport processes in the oxides. This project aims at the study of electrical properties of selected oxide films (Al2O3, Cr2O3, YSZ and oxides formed on alloys) at high temperatures by impedance spectroscopy. The results yield information on ionic transport in the oxides and the influence of alloying elements. Moreover, measurements are also performed for oxides/alloys in flame plasma to obtain results relevant for the applications.
(4) Monitoring of corrosion resistance of copper in repository environments - Corrosion resistance of copper canisters in repository environments is an important issue in Swedish nuclear waste management. In this project, the influence of defects on pitting corrosion resistance is investigated, and real-time monitoring of copper corrosion is performed at the Aspö Hard Rock Laboratory (HRL) by means of electrochemical noise analysis and other electrochemical techniques. Meanwhile, similar measurements are performed at KTH to support and verify the field measurements.
(5) Metal release from stainless steel and other metallic particles - To assess health risks in processing and uses of stainless steel and other metallic particles, it is necessary to determine the metal release from the materials in relevant environments. The project aims at establishing suitable methods for study of metal release from stainless steels and metallic particles, and determine the amount and elements of the metal released into synthetic solutions. The data provides scientific basis for the risk assessment and regulations.