Phase relation and microstructure of NbCr{sub 2} Laves intermetallics in ternary Nb-Cr-X alloy systems
- Miyagi National Coll. of Technology, Natori, Miyagi (Japan)
- Tohoku Univ., Sendai (Japan). Inst. for Materials Research
The isothermal phase diagrams of ternary alloy systems Nb-Cr-V and Nb-Cr-Mo are determined by metallography, X-ray diffraction (XRD) and transmission electron microscopy (TEM) equipped with energy dispersive X-ray (EDX). In two alloy systems, the C15 NbCr{sub 2} Laves phases are equilibrated directly with bcc solid solution without forming any intermediate phases. Relatively large amount of ternary elements V and Mo are soluble in the C15 NbCr{sub 2} Laves phases. It is shown that the C15 Laves phases extend along directions so that V occupies Cr site while Mo occupies Nb site. Also, characteristic structure containing micro twins and stacking faults is observed in the C15 Laves phase alloyed with Mo. Bcc phase has a wider solid solution range in the X(=V and Mo)-rich side than the Nb-rich and Cr-rich sides. A variety of duplex microstructures are observed depending on alloy system and alloy composition.
- OSTI ID:
- 571896
- Report Number(s):
- CONF-961202--
- Country of Publication:
- United States
- Language:
- English
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