Oxidation behavior of sulfidation processed TiAl-2 at. % X (X = V, Fe, Co,Cu, Nb, Mo, Ag and W) alloys at 1173 K in air

Citation
T. Izumi et al., Oxidation behavior of sulfidation processed TiAl-2 at. % X (X = V, Fe, Co,Cu, Nb, Mo, Ag and W) alloys at 1173 K in air, INTERMETALL, 9(7), 2001, pp. 547-558
Citations number
26
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Apllied Physucs/Condensed Matter/Materiales Science","Material Science & Engineering
Journal title
INTERMETALLICS
ISSN journal
0966-9795 → ACNP
Volume
9
Issue
7
Year of publication
2001
Pages
547 - 558
Database
ISI
SICI code
0966-9795(200107)9:7<547:OBOSPT>2.0.ZU;2-J
Abstract
The oxidation behavior of sulfidation processed TiAl-2 at. % X (X=V, Fe, Co , Cu, Nb, Mo, Ag, and W) alloys was investigated at 1173 K in air for up to 630 ks under a heat-cycle condition between 1173 K and room temperature. O xidation behavior was classified into two groups: group A with alloys conta ining Fe, Nb, Mo and W, and group B containing V, Co, Cu and Ag. The TiAl b inary alloy belonged to group B. During the sulfidation processing, the all oying elements in group A formed aluminides on the TiAl3 layer, while the g roup B alloys formed a TiAl3 (TiAl, included) layer including a small amoun t of the third element. The cross-sectional microstructures for group A sho w the sequence; oxide scale/TiAIX/TiAl2/alloy substrate, and for group B ox ide scale/Ti3Al/alloy substrate. The alloys in group A (except Nb containin g alloy) showed some scale exfoliation at the initial stage of oxidation, b ut only very little exfoliation after long oxidation times, whereas alloys in group B showed little exfoliation at the first several cycles, and then tended to exfoliate significantly, resulting in very rapid oxidation. The T iAlX/TiAl2 layers formed by the reaction between the X-aluminide and TiAl3 improve the oxidation properties of the group A alloys. (C) 2001 Elsevier S cience Ltd. All rights reserved.