The wettability as well as the corrosion resistance of metal is closely related to the surface microstructure. A surface structure with micro protrusion and nano ripple was designed and constructed on 316L stainless steel by femtosecond pulse laser. Superhydrophobic surfaces with a great contact angle over 150° were obtained by surface modifications of heat treatment or fluorination treatment. The corrosion resistance of the superhydrophobic micro-nano structured surfaces was studied through electrochemical testing. The result of polarization curve revealed that the superhydrophobic micro-nano structured surfaces possessed a higher corrosion potential, signifying the susceptibility to corrosion was reduced. Besides, the results of impedance indicated that the superhydrophobic micro-nano structured surfaces exhibited greater total resistance when compared to the original surface, demonstrating the corrosion resistance was enhanced. According to the results, the superhydrophobic surface, characterized by its micro-nanostructure, facilitates the formation of a protective gas film. Additionally, the intricate micro-nano rough structure, in conjunction with the gas film, effectively shields the underlying surface from infiltrative processes, thereby mitigating the potential exacerbation of corrosion phenomena.

The superhydrophobic coating was created on the surface of AZ31B using a one-step hydrothermal method. Various characterisation techniques, including scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), contact angle goniometer, and electrochemical workstation, were employed to characterise its morphology, composition, hydrophobicity and corrosion resistance. The prepared coating from a 5-hour hydrothermal reaction exhibited a double-layer structure with a dense inner oxide layer and an outer layer of needle-like micro-nano structures. Achieving a water contact angle (WCA) as high as 159°, the superhydrophobic coating demonstrated low water adhesion and excellent self-cleaning properties. In a 3.5 wt-% NaCl aqueous solution, its corrosion rate was 5 orders of magnitude lower than that of the bare Mg alloy. Furthermore, the coating maintained a high impedance modulus value at 0.01 Hz (∼6.85 × 106 Ω cm2) after immersion in 3.5 wt-% NaCl solution for 25 days, which was attributed to the synergistic effect of the inner and outer layers. This study introduces a strategy for preparing long-term corrosion-resistant superhydrophobic coating on Mg alloy.

Pipelines are ubiquitous engineering structures used to transport fluid substances. To increase the durability and lifespan of pipes, engineers often coat chemically inactive materials onto the inner and/or outer surfaces of pipes, resulting in coated pipes. This article offers a review of research on coated pipes with a focus on their material selections, manufacturing methods, failure mechanisms and protection approaches. The information provided in this review article will be of great value to researchers and engineers dedicated to the design and manufacturing of coated pipes and their applications.

The influence of organic acids (formic acid, acetic acid) on the corrosion behaviour of 110SS steel, a hydrogen sulphide corrosion resistant alloy steel, in hydrochloric (HCl) acid environments was studied. The corrosion rates of 110SS steels in HCl acid and blended acid were measured using the high-temperature and high-pressure corrosion tester. Scanning electron microscopy was utilised to observe the morphology of corrosion products on steel samples corroded by different acid systems, and the energy dispersive X-ray spectrometer was used to analyse the elemental composition of the corrosion products. The corrosion morphology was observed using a 3D laser scanner. The results indicated that the corrosion rate of 110SS steel in HCl acid at 200 °C was an exponential function of HCl concentration. Reducing the HCl concentration significantly decreased the corrosion rate of 110SS steel. Organic acids and corrosion inhibitors synergistically reduced the corrosion of 110SS steel in HCl acid. Adding 3 wt.% organic acid to the 15 wt.% HCl acid system further reduced the corrosion rate, with a more pronounced effect observed in the HCl–formic acid system compared to the HCl–acetic acid system. Organic acids chemically adsorbed onto the steel surface and decomposed to produce CO, which hindered the attack of hydrogen ions on the metal. The added corrosion inhibitor and intensifier Sb2O3 resulted in the formation of a compact adsorption film on the steel surface, further inhibiting corrosion. The optimal mass ratio of HCl acid to organic acid was found to be 15% to 3%.

Hearing aids (HA) are low-power electronic devices used worldwide. The ongoing trend in the HA industry has been to move towards Li-ion battery technology replacing conventional zinc-air batteries. The corrosion reliability of HA devices is a critical issue, due to their exposure to harsh user environments including body fluid contact, high humidity, and temperature. The combined effect of higher operating voltage (4.3 V) and design miniaturisation poses new risks for corrosion reliability. To fully understand the environmental reliability issues of the Li-ion powered HA, it is crucial to investigate field performance by conducting root cause failure analysis on the field-returned failed devices. This study investigated two different HA models (open vs. glued model). The analysis used a systematic FMEA-based approach to identify and understand failure modes, mechanisms, and potential causes using various analysis techniques (e.g., LOM, SEM&EDS, and ICP-OES). Furthermore, statistical analysis was conducted based on the repair data created by the global service centre to reveal the failure percentage, and time to failure of different components. Passive components, solder connections, and galvanic charging contact showed the highest failure percentages. The most common causes of corrosion failures were high levels of chloride ions, high humidity, flux residues, and insufficient coating protection.

Stress corrosion cracking (SCC) poses a significant challenge to the integrity and longevity of both conventional and advanced manufactured alloys, impacting critical industries such as aerospace, marine, and nuclear energy. This review explores the use of artificial intelligence (AI) to analyse and predict SCC properties. Traditional alloys such as steel, aluminium, and titanium, as well as advanced materials such as additive-manufactured and high-entropy alloys, exhibit unique SCC behaviours influenced by corrosive environments, mechanical stress, and temperature variations. AI techniques, including machine learning models, offer transformative approaches to understanding and mitigating SCC. Leveraging extensive datasets from experiments and field studies, AI can identify patterns and correlations that traditional methods might miss. Predictive modelling through supervised learning forecasts SCC initiation and propagation, aiding in material design and maintenance. Unsupervised and reinforcement learning enhances alloy composition and processing parameter optimisation for better SCC resistance. In conventional alloys, AI identifies specific SCC conditions, leading to improved protective measures. For advanced alloys, AI-driven insights tailor additive manufacturing processes and design high-entropy alloys with superior corrosion resistance. This review includes case studies demonstrating AI's effectiveness in predicting SCC across various alloy–environment combinations, highlighting successes and challenges. Despite hurdles such as data quality and integration, AI holds immense potential to revolutionise SCC research, enhancing understanding of SCC mechanisms and fostering innovations in alloy design and preventative maintenance.