High Temperature Oxidation Behavior of TiAl-Base Alloys with Additions of Third Elements

Kondo, Kazuo; Hashimoto, Keizo; Doi, Haruo; Tsujimoto, Tokuzou

doi:10.2320/jinstmet1952.54.8_948

Cited by 45 publications

(17 citation statements)

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“…The influence of alloying additions on the oxidation behavior of TiAl-base alloys has been investigated extensively. [6][7][8][9][10][11][12][13][14][15][16][17] For example, small amounts of Nb improved the oxidation resistance of TiAl-base alloys, while a very high-Nb content reduced the oxidation resistance. 6 Cr additions of more than 8 at.% improved the isothermal-and cyclic-oxidation resistance of TiAl alloys, while Cr was detrimental to the oxidation resistance with small amounts less than 4 at.%.…”

Section: Introductionmentioning

confidence: 99%

Isothermal Oxidation Behavior of Ti-50Al Alloy with Y Additions at 800 and 900°C

Umakoshi

et al. 2006

Oxid Met

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The isothermal-oxidation behavior of Al-rich TiAl alloys containing Y up to 1.0 at.% was studied in synthetic air with a flow of 200-250 mL/min at 800 and 900°C. Oxidation kinetics and scale adherence were studied in terms of the morphological features and microstructural evolution of the oxide scale. In the specimens oxidized at 800°C, all alloys containing 0.3-1.0 at.%Y showed reduced mass gain compared to the Y-free alloy, especially for the 0.3 at.%Y alloy. Under isothermal exposure at 900°C, the addition of small amounts of Y (0.1 and 0.3 at.%) was effective in enhancing the oxidation resistance. The alloys with higher Y contents (0.6 and 1.0 at.%), on the contrary, had a reverse effect on the oxidation resistance by providing rapid diffusion paths in the form of coarse Y 2 O 3 particles close to the substrate. The improvement of oxidation resistance of the alloy with Y additions was due partly to the improved adhesion of the scale and due partly to the formation of a continuous a-Al 2 O 3 layer in the outer scale. Y segregation and/or Y 2 O 3 precipitation at the oxide grain boundaries was effective in decreasing the oxidation rate and refining the oxide grains. The thinner scale was responsible for relaxing the thermal stress and, thus the cohesion between the scale and substrate was greatly improved in Y-containing alloys.

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Section: Introductionmentioning

confidence: 99%

Isothermal Oxidation Behavior of Ti-50Al Alloy with Y Additions at 800 and 900°C

Umakoshi

et al. 2006

Oxid Met

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“…4(b), Mn was distributed randomly in the oxide layer. Though Mn tended to segregate at the outermost oxide layer, 2) it frequently existed as discrete islands scattered over the whole oxide layer. 3,4) The fine Pt markers initially placed on the alloy surface prior to oxidation were seen to be embedded around the intermediate Al 2 O 3 layer.…”

Section: Resultsmentioning

confidence: 99%

“…The oxidation tests on arc-melted Ti-(47.3-49.0%)Al-(1.0-3.35%)Mn in temperature range 1173-1223 K indicated that Mn, which oxidized to MnTiO 3 , was detrimental to oxidation resistance. [2][3][4] Mn was segregated above the outer TiO 2 layer, 2) at the lower part of the inner oxide layer as well as the outermost layer, 3) or at the inner oxide layer. 4) In this paper, a more detail study utilizing such as the Pt marker testing and TEM was undertaken on the thermomechanically treated Ti47%Al1%Mn alloy to investigate the Mn effect, the oxidation kinetics and mechanism.…”

Section: Introductionmentioning

confidence: 99%

High Temperature Oxidation of Ti-47%Al-1%Mn Alloy

2002

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The thermomechanically treated Ti-47%Al-1%Mn alloy was oxidized in air at 1073, 1173, and 1273 K. When compared to Ti-47%Al, the oxidation resistance of Ti-47%Al-1%Mn was better at 1073 K, slightly better at 1173 K, but poorer at 1273 K. The scale adherence was improved by the addition of Mn to a certain degree. The oxidation products were TiO 2 and α-Al 2 O 3 , together with a very small amount of MnTiO 3 , Mn 2 O 3 , TiN and Ti 2 AlN. Within the (TiO 2 , Al 2 O 3 ) oxide grains, some dissolution of Mn was noticed. The oxidation progressed via the outward diffusion of Ti ions to form the outer TiO 2 layer, and the inward transport of oxygen to form the inner (TiO 2 + Al 2 O 3 ) mixed layer, between which an intermediate Al 2 O 3 layer existed. Subsurface zone within the metal phase was depleted in Al.

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“…XRD tests indicated that the major phase of oxides formed was TiO 2 , while Al 2 O 3 accounted for the minor phase. The oxides of Mn, i.e., MnTiO 3 [8][9][10] and Mn 2 O 3 [11]werevaguely detected, because Mn was mostly dissolved in the oxide scale. Also, weak diffraction patterns of TiN and Ti 2 AlN, which are known to exist at the scale-matrix interface [12], are frequently detected [13].…”

Section: Ti47al-1mn Alloysmentioning

confidence: 99%

Effect of Cr, Nb, Mn, V, W and Si on high temperature oxidation of TiAl alloys

Lee

2005

Met. Mater. Int.

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Alloys of Ti-(47,51)Al, were oxidized at temperatures between 800 and 1000 o C in air to determine the effect of each alloying element on oxidation behavior. Among the alloys tested, the Ti48.4Al-1.9W alloy displayed the best oxidation resistance, due to the beneficial effects of W, whereas the Ti39.4Al-10V alloy displayed the worst oxidation resistance, due to the formation of volatile V-oxides. Cr was harmful while Nb was beneficial. The oxidation rate of each alloy was not strictly proportional to temperature, because each alloying element had different temperature sensitivity with respect to oxidation rate.

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High Temperature Oxidation Behavior of TiAl-Base Alloys with Additions of Third Elements

Cited by 45 publications

References 0 publications

Isothermal Oxidation Behavior of Ti-50Al Alloy with Y Additions at 800 and 900°C

Isothermal Oxidation Behavior of Ti-50Al Alloy with Y Additions at 800 and 900°C

High Temperature Oxidation of Ti-47%Al-1%Mn Alloy

Effect of Cr, Nb, Mn, V, W and Si on high temperature oxidation of TiAl alloys

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