Formation mechanism of the Nb2C phase in the Nb–1Zr–0.1C (wt.%) alloy and interrelation between γ, β and α-Nb2C carbide phases

Formation mechanism of stable NbC carbide phase in Nb-1Zr-0.1C (wt.%) alloy

Niobium-based alloys are well-established refractory materials; as a result of their high melting temperature and good creep properties, these alloys find their applications in nuclear reactors. The present study deals with a microstructural response of these materials during hot working. The evolution of microstructure and texture during high-temperature deformation has been investigated in the temperature range 1500-1700A degrees C and strain rate range of 0.001-0.1 s(-1). For each deformed sample, the microstructure has been examined in detail. The microstructural features clearly revealed the formation of a substructure and the occurrence of dynamic recrystallization in a proper temperature-strain rate window. At low strain rates, the necklace structure formation was more prominent.

Microstructural Features of Hot Deformed Nb-1Zr-0.1C Alloy

The use of thorium is necessary from a long-term objective of sustainability of nuclear energy resources in India. Its use requires reprocessing to separate the fissile 233U for sustained operation using 232Th–233U. Over the years, owing to sustained technology developmental initiatives, India has gained significant experience in all aspects of the thorium fuel cycle. In addition to briefly explaining advantages and challenges of thorium fuel cycle, this paper covers the Indian experiences in this direction. It also briefly describes the designs of Indian reactors based on thorium fuel cycle, for example, the Advanced Heavy Water Reactor (AHWR), as well as conceptual designs of proposed future reactor systems.

K. Vaibhav

Papers

Development of Nb-1%Zr-0.1%C alloy as structural components for high temperature reactors