Alloy Materials Degradation and Microstructural Study

Dear Colleagues,

The demand for high-performance materials in nuclear, aerospace, and energy industries highlights the challenges of material degradation in extreme environments. Materials must withstand high temperatures, aggressive chemical conditions, and mechanical stresses, requiring a deep understanding of their microstructure, crystallinity, and failure mechanisms to enhance durability and performance.

Metallic alloys play a critical role, with crystal structure and grain orientation determining key properties. Single-crystal alloys exhibit superior creep and corrosion resistance, while polycrystalline and directionally solidified materials vary in performance based on grain boundary engineering. Atomic arrangements in BCC, FCC, and HCP structures influence strength, oxidation resistance, and fatigue life; however, point defects and dislocations contribute to degradation mechanisms like creep, fatigue, and environmental-assisted cracking.

Beyond metals, composites and polymers offer lightweight yet durable solutions for high-temperature and corrosive environments. CMCs and MMCs provide oxidation and thermal shock resistance, ideal for gas turbines, fusion reactors, and high-efficiency energy systems. However, challenges remain for radiation, extreme heat, and molten salt exposure. Polymer-based composites (PMCs) have been explored for corrosion-resistant applications, but their thermal stability and long-term performance in nuclear and renewable energy require further study.

For nuclear fusion and fission, materials must endure neutron irradiation, plasma interactions, and intense thermal cycling. Similarly, CSP and molten salt reactors (MSRs) expose materials to corrosive molten salts, necessitating research on electrochemical stability and degradation mechanisms.

In boiler systems with waste-to-energy (WtE) processes and biomass, materials must resist high-temperature corrosion from chlorine, alkali metals, and sulphur compounds. The selection of alloys and coatings is crucial for superheaters and heat exchangers, ensuring resistance to ash deposits, molten salt corrosion, and erosion.

This Special Issue invites researchers to contribute studies addressing material challenges in extreme environments, including corrosion, irradiation effects, and novel material processing techniques across nuclear, CSP, WtE, biomass, and aerospace applications.

Dr. Adnan Syed
Dr. Adrianus Indrat Aria
Dr. Juho.Lehmusto
Guest Editors

Manuscript Submission Information

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Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2100 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

• high-temperature corrosion
• material degradation
• extreme environment materials
• hot corrosion
• molten salt corrosion
• scanning electron microscopy
• mechanical properties
• corrosion mechanism
• corrosion-resistant alloys
• coatings
• microstructure characterization