Micromechanics of Tribocorrosion in Offshore Wind Turbines

Tribocorrosion is a chemical-mechanical process that degrades a material from a combination of mechanical wear, whilst simultaneously immersed in a corrosive environment. These conditions result in a complex process of wear-accelerated corrosion and corrosion-accelerated wear. This is a major problem for offshore wind turbines in the pitch and yaw bearings. Due to the constant movement and exposure to environmental elements, such as rain, saltwater spray and temperature fluctuations, the bearings are susceptible to coupled mechanical wear and corrosion, which lead to performance degradation and maintenance challenges in substantial installations, that are expensive to service. 

Electrochemical techniques permit corrosion conditions to be monitored and controlled. These methods have been applied extensively to quantify bulk corrosion kinetics, however, the strong interaction between wear and chemical effects makes it difficult to isolate the mechanical and chemical effects. In this project, electrochemical polarisation will be used to precisely control the redox potential of structural steel samples during nanoscratch testing to determine the micromechanical damage mechanisms that lead to tribocorrosion, at the asperity scale. The project will combine micromechanical testing, advanced characterisation and finite element methods to simulate the multi-physical process of tribocorrosion.