Correlative SEM, EDX and Raman microscopy of corrosive stressed components - In particular microbial corrosion (MIC), chloride induced corrosion (CIC) and alkali silica reaction (AKR)

Corrosion is a major issue in industries such as transportation and construction, with direct costs estimated at 3-5% of GDP [1] and even higher secondary costs [2]. Correlative microscopy, such as SEM, EDX, and Raman spectroscopy, is a promising tool for investigating the complex mechanisms of corrosion. MIC, which contributes to 20% of all corrosion damage [3], is a unique type of corrosion where microbes alter the corrosion process. SEM visualizes biofilms on metal surfaces, EDX identifies the elemental composition of corrosion products, and Raman microscopy provides insight into the chemical composition and crystal structure of corrosion products. CIC occurs when chloride ions penetrate steel surfaces in concrete, causing rust formation and structural damage. SEM and EDX identify the elemental composition of rust, while Raman microscopy
provides information on the crystal structure and chemical composition of rust. AKR (In colloquial language also called concrete cancer), a reaction between alkalis in cement and silicates in aggregate materials, can cause expansive cracking and damage in concrete structures. Correlative SEM, EDX, and Raman microscopy offer a powerful approach for investigating the mechanisms underlying corrosive damage in various materials, paving the way for more effective corrosion prevention and mitigation strategies. Overall, these advanced
microscopy techniques offer a promising solution for the widespread issue of corrosion in various industries.