High-temperature oxidation of Mo-rich (Mo1−xNbx)Si2 pseudo-binary compounds

Effects of Cr-addition and lamellar microstructure on the oxidation behavior of single crystal (Mo0.85Nb0.15)Si2

“…As the atomic ratio of Si is much larger than that of Nb in the (Mo 0.85 Nb 0.15 )Si 2 specimen, the oxide scale was mostly SiO 2 . Although the Mo 5 Si 3 and Nb 5 Si 3 phases could not be clearly observed by SEM observation in this study, they were assumed to exist beneath the oxide scale, similar as it was reported in [11]. The further detailed analysis on the distribution and morphology of these phases together with Si-oxide and Nb-oxide has now been conducted by TEM-EDS method, and the results will be reported elsewhere.…”

Experimental study on the as-cast solidification of the Si-rich alloys of the Nb–Si–Mo ternary system

“…Based on the present experiments as well as literature reports [22][23][24]26,28], the constructed Si-rich liquidus surface projection is shown in Fig. 5.…”

“…Many studies [14,15,20,[22][23][24][25][26] were presented on the phase equilibria of the quasi-binary MoSi 2 -XSi 2 (X ¼ Ti, Ta, V, Cr, Nb) systems, from which the possibility of an equilibrium transition between the bMoSi 2 -C40 and the aMoSi 2 -C11 b polymorphic phases for pure MoSi 2 can be precluded.…”

“…2, Yang et al [24], Zhang et al [26] and Nakano et al [22,23,28] have studied many alloys (Mo X Nb 1ÀX )Si 2 . The microstructure analysis indicated that the phase fraction of the C11 b phase reduces and that of the C40 phase increases as increasing the content of Nb when (1ÀX)<17 at%.…”

Formation and development of C40/C11b lamellar structure in NbSi2/MoSi2 crystals

“…From the result of our previous works [6] and the works by other researchers [7], it is found that a C11 b /C40 duplex phase structure is formed in the (Mo 1Àx Nb x )Si 2 pseudo-binary system when x is between 0.05 and 0.20. Further, it is observed that when an alloy whose composition is in the duplex phase region of the pseudobinary system solidifies, the primary solidified phase is the C11 b phase and the C40 phase is formed by a peritectic reaction between the liquid phase and the primary C11 b phase.…”