Liquid–solid phase equilibria in Nb-rich corner of the Nb–Ti–Si–B system

Effects of B and Si on the fracture toughness of the Nb–Si alloys

“…However, the addition of 4.5B to NbeTieSi could suppress the primary solidification of Nb 3 Si and inhibit (Nb) þ Nb 3 Si eutectic, it promotes direct eutectic solidification between (Nb) and T2 in Nb-rich corner of NbeTieSieB liquidus projection, so 4.5B would be an optimal amount to observe this critical transition, as shown in the calculated 2D liquidus projections in Fig. 1(b) [9,10]. The (Nb) þ T2 eutectic valley as well as large (Nb) þ T2 two-phase region in the isothermal tetrahedron space is of practical importance to fabricate the desirable in-situ (Nb) þ T2 composites.…”

“…(a) Calculated liquidus projection of the NbeSieTi ternary system[8] (b) Calculated 2D liquidus section of NbeTieSieB (X B ¼ 4.5 at%)[9,10]. The symbols denote the experimentally investigated alloy compositions.…”