Microstructure of as atomized and annealed U-Mo7 particles: A SEM/EBSD study of grain growth

Characterization of fresh EMPIrE and SEMPER FIDELIS U(Mo)/Al fuel plates made with PVD-coated U(Mo) particles

“…3a,b,g). The four other ones are characterized by large grains which reach a size of the order of several tens of microns, as expected after a 1000°C 1 h annealing [7,8]. In some cases, single crystalline particles are encountered (see for example Fig.…”

“…Grains are more or less difficult to distinguish, since they almost systematically contain lamellas with darker contrasts. Such features were already observed in certain particles from heat treated KOMO-5 powder batches and were interpreted as Widmanstätten microstructures which could appear depending on the cooling rate conditions [7]. They were also present in certain particles from heat treated EMPIrE powder batches (even if this point was not illustrated in [7]), but to a lower extend than in the EMPIrE plates.…”

“…Such features were already observed in certain particles from heat treated KOMO-5 powder batches and were interpreted as Widmanstätten microstructures which could appear depending on the cooling rate conditions [7]. They were also present in certain particles from heat treated EMPIrE powder batches (even if this point was not illustrated in [7]), but to a lower extend than in the EMPIrE plates. Batch to batch variabilities linked to cooling conditions after homogenization and/or an incidence of the thermal history during plates manufacturing could explain why these lamellas are numerous in plates made with heat treated U(Mo) particles.…”

“…SEM examinations were carried out mainly in backscattered electrons mode (BSE), with a FEI Nova Nano SEM 450, equipped with an Oxford Instruments EDS system. The mean Mo content in U(Mo) particles was determined by EDS, on 15 particles per plate [7].…”

Texture Analyses and Microstructural Evolution in Irradiated Monolithic U-Mo Nuclear Fuel

“…While conventional sample preparation methods are widely used in materials science, they often do not lead to quality electron backscattered patterns needed for characterization of the nuclear materials [3]. Due to challenges associated with handling radiological specimens, rapid oxidation of the specimens, and "artifacts" (high number of defects, precipitates and/or porosities) [3][4][5][6][7]. Thus, the Focused Ion Beam (FIB) glazing technique [1,4,6] has been used and optimized for EBSD collection for this fuel type.…”