#microstructure

Researchers investigate microstructure evolution of oxide films of Fe-Cr–based alloys

Ferritic/martensitic steels and austenitic steels are the primary candidate materials for advanced nuclear energy systems. The corrosion resistance of the materials is one of the factors that ensures the safe service of key components. Since the corrosion resistance of materials is highly related to the characteristics of the formed oxide films, it is crucial to investigate the oxide films of candidate materials in high-temperature water. Researchers at the Institute of Modern Physics (IMP) of the Chinese Academy of Sciences (CAS) selected candidate materials (15-15Ti, 316L and T91) to study their early oxidation behavior in high-temperature steam and the evolution process of the oxide microstructure. The results were published in Journal of Materials Science & Technology. The Ni-rich layer in the oxide film of austenitic steels (15-15Ti, 316L) is composed of Fe-Cr spinel oxide and Ni-rich phase. Researchers at IMP found a large number of nanopores in the inner oxide layer that could serve as a rapid gas transport channel for oxidant. They revealed the evolution process of Ni-rich layer and the formation mechanism of nanopores in the inner oxide layer.

Joris Laarman’s Soft Gradient Chair (Dual Cell), 2014, 

From his Microstructures series,

Thermoplastic polyurethane, a 3-D printed material. 

Researchers reveal nano-hardness and microstructure evolution of nitride coating under irradiation

Researchers from the Institute of Modern Physics (IMP) of the Chinese Academy of Sciences have obtained new results on the nano-hardness and microstructure evolution of nano-structured titanium-aluminum-nitride (TiAlN) coating under irradiation. Results were published in Surface & Coatings Technology.

Transition metal nitrides coating materials, especially titanium nitride (TiN) coatings, exhibit high hardness, chemistry inertness, excellent wear and corrosion resistance. These properties enable them to serve as superior protective coatings on nuclear reactor structure materials. However, the extreme radiation environment in nuclear reactors may change their properties and degrade their performance. Thus, it is essential to conduct research on the radiation response of the coating materials.

Researchers at IMP have studied the radiation-induced changes in the properties of TiN-based coating materials. They selected TiAlN as an isostructure model material to investigate the irradiation induced nano-hardness and microstructure evolution, and the relationship between them.