Effects of Cr-addition and Lamellar Microstructure on the Oxidation Behavior of Single Crystal (Mo0.85nb0.15)si2

The oxidation behavior of (Mo0.85Nb0.15)Si-2 single crystals and the influence of Cr-addition were studied focusing on its microstructure dependence. Cr-addition to single-phase C40-structured (Mo0.85Nb0.15)Si-2 crystal induced the formation of crystalline silica, leading to slightly larger weight gain during the oxidation test at 1200 degrees C. Furthermore, Cr-addition to C40/C11(b) duplex-phase (Mo0.85Nb0.15)Si-2 crystal with lamellar structure strongly suppressed the internal oxidation of the C11(b) phase, resulting in excellent oxidation resistance. C40/C11(b) lamellae-structured crystals showed better oxidation resistance than the C40-structured crystals. (C) 2010 Elsevier B.V. All rights reserved.