The effect of various ternary additives on the oxidation behavior of TiAl in high-temperature air

Journal Article · Thu Feb 01 04:00:00 EST 1996 · Oxidation of Metals

DOI:https://doi.org/10.1007/BF01046826· OSTI ID:245138

Shida, Yoshiaki; Anada, Hiroyuki ^[1]

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1. Advanced Technology Research Laboratories, Amagasaki (Japan)

Twenty-four ternary element additions were made to a binary TiAl alloy (Ti-34.5 wt.% Al), and the oxidation behavior was studied. As a result of the oxidation tests in air at 1173 K for 360 ks, ternary elements were classified into three groups according to their effects, namely, (1) detrimental; V, Cr, Mn, Pd, Pt, Cu; (2) neutral; Y, Zr, Hf, Ta, Fe, Co, Ni, Ag, Au, Sn, O; (3) beneficial; Nb, Mo, W, Si, Al, C, B. This classification was valid for Cr, Mn, Mo, and W under several other temperature and time conditions. The influence of the additions was very significant, the difference in the weight gain between the best and the worst alloys being approximately two orders of magnitude. As a result of detailed examinations, it was confirmed that Cr and Mn additions caused linear-oxidation behavior from the outset at 1173 K, virtually no Al{sub 2}O{sub 3} barrier being formed. This is probably due to the doping of those elements in TiO{sub 2}. The beneficial elements, such as Mo, Nb, W, resulted in protective-oxidation behavior. The characteristic features of the scale on those alloys were the presence of a continuous Al{sub 2}O{sub 3} layer as the second layer from the outer surface and the relatively massive precipitation of Al{sub 2}O{sub 3} in the vicinity of the scale-metal interface. Also, these alloys did not show any evidence of internal oxidation. The scale types and the proposed mechanism for the inner-scale formation are described.

• Sponsoring Organization: USDOE
• OSTI ID: 245138
• Journal Information: Oxidation of Metals, Journal Name: Oxidation of Metals Journal Issue: 1-2 Vol. 45; ISSN OXMEAF; ISSN 0030-770X
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM ADDITIONS
ALUMINIUM ALLOYS
ALUMINIUM OXIDES
BORON ADDITIONS
CARBON ADDITIONS
CHROMIUM ADDITIONS
COBALT ADDITIONS
COPPER ADDITIONS
GOLD ADDITIONS
HAFNIUM ADDITIONS
IRON ADDITIONS
MANGANESE ADDITIONS
MOLYBDENUM ADDITIONS
NICKEL ADDITIONS
NIOBIUM ADDITIONS
OXIDATION
OXYGEN ADDITIONS
PALLADIUM ADDITIONS
PLATINUM ADDITIONS
SCALING
SILICON ADDITIONS
SILVER ADDITIONS
TANTALUM ADDITIONS
TEMPERATURE RANGE 1000-4000 K
TIN ADDITIONS
TITANIUM BASE ALLOYS
TUNGSTEN ADDITIONS
VANADIUM ADDITIONS
YTTERBIUM ADDITIONS
ZIRCONIUM ADDITIONS