Some new experimental results on the Zr–Nb–Fe system

Experimental investigation of phase equilibria in the Zr–Nb–Cr system at 1573 K and 1373 K

“…During solidification, the high-temperature hexagonal Laves phases (C14/ C36) transform to the low-temperature cubic (C15) phase. However, the transformation is usually incomplete and the hexagonal Laves phases remain at low temperatures due to the fast cooling speed [14]. Bodega and Fern andez [15] synthesized C15eCr 2 Zr and C14eCr 2 Zr by melting in an arc furnace and demonstrated that the sluggish arc extinction is helpful to obtain the single C15 phase.…”

Thermodynamic modeling of the U–Mn and U–Nb systems

“…The investigations of U-based alloys focus not only on the U compounds used in the fuels, but also on the alloys of U and common elements of the structural materials and fission products [1][2][3]. Mn and Nb are very important alloying elements for the U-based alloys [4][5][6][7][8][9]. In order to develop new nuclear materials, it is necessary to understand the phase equilibria in U-based alloy systems.…”

Formation and fine-structures of nano-precipitates in ZIRLO

“…On the basis of the valence electron concentration, they reported a cubic C15-type structure for x < 0.35 and a hexagonal C14-type structure for x > 0.5. However, recent experimental work by Ramos et al showed that Nb mainly substitute Fe in the 2a, 6h site in the C14 laves phase instead [7] . Ramos et al obtained different compositions of the C14 compound by adjusting the contents of alloying constituents Fe and Nb.…”

“…According to the parameter R proposed by Shishov, the precipitates should be the body-centered-cubic β-Nb and the hexagonal Zr-Fe-Nb phase. For the Zr-Fe-Nb phase, Granovsky [6] , Ramos [7] , Barberis [8] , and Toffolon-Masclet [9] independently prepared some Zr-Sn-Nb-Fe alloys, and carried out structural study of precipitated phases. They concluded that the Zr-Nb-Fe particles can be divided into FCC and HCP structures, the former space group was Fd 3m (Ti2Ni type), while the latter had 3 6/ P mmc space group (MgZn2 type, C14).…”