Nano-structured alloys against corrosion in advanced nuclear plants
New experiments, new insights could improve efficiency & reliability of power plants and other systems
[I]f we had a better understanding of the relationship between grain-boundary structure, response to mechanical stress, and resistance to corrosion, we might be able to create a surface structure or texture that would help inhibit stress corrosion cracking.
Bilge Yildiz, associate professor
High stresses combined with a corrosive environment can cause critical components inside power plants and other systems to crack and fail, sometimes with little warning. MIT researchers now have new insights into how such “stress corrosion cracking” may be affected by nanoscale disruptions in the crystalline structure of metallic materials. Using novel experimental methods, they showed that mismatches between adjacent crystals can create regions with altered mechanical properties, including hardness. In addition, those defects can change the electronic properties of the surface in the region, making reaction with oxygen more likely and accelerating the pace of corrosion. Ultimately, the MIT researchers hope to define nanostructures that can help prevent this pervasive, insidious form of material degradation and failure.