Thermodynamic assessment of the Fe-U binary system

Preparation and melting of uranium from U3O8

“…Its peritectic transformation to liquid and bcc-uranium occurs at 831 • C [10,11] and thus it can be consolidated below the temperatures where the oxidation of uranium by Li 2 O prevails. While pure uranium metal was also observed at the outer-part of the cathode product (Fig.…”

A calorimetric study of high temperature phase stability in Fe–U alloys

“…According to Gordon and Grogan's investigations [6,7], the first eutectic composition occurs at 45 mass% of uranium, whereas the work of Chapman et al, suggests 47 mass% of uranium [9]. The composition of the second eutectic is identified to be 89 mass% of uranium, which is accepted in literature [5][6][7][8][9][10][11][12].…”

“…There exists a fair amount of phase equilibria and thermochemistry related information on FeÀU system, which has been the subject of recent assessment by Chatain et al [5]. The equilibrium solubility of uranium in a-iron and that of Fe in a-U at room temperature are negligible [6,7,12].…”

“…According to the currently accepted equilibrium diagram [5], the UÀFe binary is characterized by the presence of two almost stoichiometric intermetallic phases, namely Fe 2 U and FeU 6 , which are connected to the high temperature liquid phase on either end by two eutectic reactions. On the Fe-rich side, the eutectic reaction involving liquid, Fe 2 U and c-Fe occurs at 1353 ± 5 K, whereas the other one involving FeU 6 and Fe 2 U is relatively deep and is located at 998 ± 5 K. In literature, there is some uncertainty surrounding the correct compositional placement of the first eutectic involving Fe 2 U [5][6][7][8][9][10][11][12]. According to Gordon and Grogan's investigations [6,7], the first eutectic composition occurs at 45 mass% of uranium, whereas the work of Chapman et al, suggests 47 mass% of uranium [9].…”

“…It is in this respect, that in the present study, a comprehensive calorimetric characterization of various phase changes that take place as a function of temperature in several FeÀU binary alloys is undertaken. However, before proceeding further, a brief review of the existing knowledge of high temperature phase equilibria in FeÀU binary system is briefly summarized [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21].…”