UKAEA Papers

"Segregation, ordering, and precipitation in WTaV-based concentrated refractory alloys"

• Jesper Byggmästar
• Damian Sobieraj
• Jan S. Wróbel
• Daniel K. Schreiber
• Osman El-Atwani
• Enrique Martinez
• Duc Nguyen-Manh

Tungsten-based low-activation high-entropy alloys are possible candidates for next-generation fusion reactors due to their exceptional tolerance to irradiation, thermal loads, and stress. We develop an accurate and efficient machine-learned interatomic potential for the W–Ta–Cr–V system and use it in hybrid Monte Carlo mo…

"Thermodynamic Assessment of the Quaternary WTaCrV Refractory High Entropy Alloy as a Means to Guide Experimental Approaches"

• Bochuan Sun
• Mark Fedorov
• Jan Wrobel
• Duc Nguyen-Manh
• Caleb Hatler
• Matthew Vigil
• Dan J. Thoma
• Osman El-Atwani
• Enrique Martinez

High-entropy alloys (HEAs) are being explored as potential candidates for radiation-tolerant materials, with some compositions exhibiting good resistance to defect cluster formation. One such system is WTaCrV, although only a single composition has been experimentally tested under ion irradiation, where it showed phase decomposition at low temperat…

"Generalized universal equation of states for magnetic materials: A novel formulation for an interatomic potential in Fe"

• Isaac Toda-Caraballo
• Jan S. Wróbel
• Duc Nguyen-Manh

The development of quantitative models for understanding physical properties of alloys requires a proper treatment of magnetic interactions, which is of paramount importance for the microstructural stability, especially in steels and high-entropy alloys containing magnetic elements. These magnetic interactions also control the defects behavior w…

"Precipitation of Cr-rich clusters in Fe-Cr alloys: Effects of irradiation from first principles modeling and experimental observations"

• Mark Fedorov
• Jan S. Wróbel
• Andrew J. London
• Krzysztof J. Kurzydłowski
• Chu-Chun Fu
• Tonˇci Tadi´
• Sergei L. Dudarev
• Duc Nguyen-Manh

"Co-segregation of Y and Zr in W-Cr-Y-Zr alloys: First-principles modeling at finite temperature and application to SMART materials"

• Damian Sobieraj
• Jan S. Wróbel
• Mark R. Gilbert
• Krzysztof J. Kurzydłowski
• Duc Nguyen-Manh

Spinodal phase separation in SMART (Self-passivating Metal Alloys with Reduced Thermo-oxidation) materials based on binary W-Cr with alloying elements Y and Zr is systematically investigated by a combination of Density Functional Theory with Cluster Expansion Hamiltonian and large-scale Monte Carlo simulations with thermodynamic integration. Compar…

"Predicting short-range order evolution in WTaCrVHf refractory high-entropy alloys"

• Andrew M. Alvarado
• Chanho Lee
• Jan S. Wróbel
• Damian Sobieraj
• Duc Nguyen-Manh
• Jonathan D. Poplawsky
• Saryu Jindal Fensin
• Enrique Martinez
• Osman El-Atwani

Short-range order (SRO) in multicomponent concentrated alloys affects their mechanical response. Hence, is paramount to understand how composition modifies the chemical ordering in the system to design materials with optimal properties. We present here a methodology to predict the SRO and thermodynamic properties in chemically complex systems an…

"Co-segregation of Y and Zr in SMART materials: Prediction from first-principles modelling at finite temperature"

• Damian Sobieraj
• Jan S. Wróbel
• Mark R. Gilbert
• Andrey Litnovsky
• Krzysztof J. Kurzydłowski
• Duc Nguyen-Manh

Spinodal phase separation in SMART materials based on binary W-Cr with alloying 1 elements Y and Zr is systematically investigated by a combination of Density Functional Theory with Cluster Expansion Hamiltonian and large-scale Monte Carlo simulations with thermodynamic integration. Comparing alloying of Zr with those from Y, it is shown that there…

"Radiation-induced precipitation of chromium in Fe-Cr alloys containing C and N impurities: First-principles modelling and experimental observations"

• Mark Fedorov
• Jan S. Wróbel
• Andrew J. London
• Krzysztof J. Kurzydłowski
• Chu-Chun Fu
• Tonči Tadić
• Sergei L. Dudarev
• Duc Nguyen-Manh

Using exchange Monte Carlo (MC) simulations based on an ab initio-parameterized Cluster Expansion (CE) model, we explore the phase stability of low-Cr Fe-Cr alloys as a function of vacancy (Vac), carbon, and nitrogen interstitial impurity content. To parameterise the CE model, we perform density functional theory calculations for more than 1600 …

"Composition stability of single phase in Cr-Fe–Mn-Ni alloys at high temperature: First-principles prediction and experimental validation"

• Mark Fedorov
• Jan Wrobel
• Witold Chromińskia
• Grzegorz Cieślak
• Magdalena Płocińska
• Krzysztof J. Kurzydłowski
• Duc Nguyen-Manh

"Mechanical Characterisation of V-4Cr-4Ti Alloy: Tensile Tests Under High Energy Synchrotron Diffraction"

• Tay Sparks
• Duc Nguyen-Manh
• Pengfei Zheng
• Jan S. Wróbel
• Michael Gorley
• Thomas Connolley
• Christina Reinhard
• Yiqiang Wang
• Biao Cai

Vanadium base alloys represent potentially promising candidate structural materials for use in nuclear fusion reactors due to vanadium’s low activity, high thermal strength, and good swelling resistance. In this work, the mechanical properties of the current frontrunner vanadium base alloy, V-4Cr-4Ti, have been interrogated using in-situ high ene…