High-Temperature oxidation of cathodically hydrogen-charged two-phase (Ti3Al, TiAl) titanium aluminides

1994 ◽  
Vol 25 (11) ◽  
pp. 2491-2496 ◽  
Author(s):  
Akito Takasaki ◽  
Kozo Ojima ◽  
Youji Taneda
Keyword(s):  
High Temperature ◽  
High Temperature Oxidation ◽  
Titanium Aluminides ◽  
Two Phase ◽  
Temperature Oxidation

High-Temperature Oxidation Behavior of Two-Phase Iron-Manganese-Aluminum Alloys

CORROSION ◽  
2000 ◽  
Vol 56 (4) ◽  
pp. 339-349 ◽  
Author(s):  
S.-Y. Liu ◽  
C.-L. Lee ◽  
C.-H. Kao ◽  
T.-P. Perng
Keyword(s):  
High Temperature ◽  
Aluminum Alloys ◽  
High Temperature Oxidation ◽  
Oxidation Behavior ◽  
Two Phase ◽  
Temperature Oxidation ◽  
Manganese Aluminum ◽  
High Temperature Oxidation Behavior ◽  
Iron Manganese

High-temperature oxidation of Ti3Al-based titanium aluminides in oxygen

1996 ◽  
Vol 27 (12) ◽  
pp. 3993-4002 ◽  
Author(s):  
T. K. Roy ◽  
R. Balasubramaniam ◽  
A. Ghosh
Keyword(s):  
High Temperature ◽  
High Temperature Oxidation ◽  
Titanium Aluminides ◽  
Temperature Oxidation

Comparison of Fluorination Treatments to Improve the High Temperature Oxidation Resistance of TiAl Alloys in SO2 Containing Environments

2010 ◽  
Vol 638-642 ◽  
pp. 1374-1378 ◽  
Author(s):  
Patrick J. Masset ◽  
Rossen Yankov ◽  
Andreas Kolitsch ◽  
Michael Schütze
Keyword(s):  
High Temperature ◽  
Sulfur Dioxide ◽  
Ion Implantation ◽  
Oxide Scale ◽  
Oxidation Resistance ◽  
High Temperature Oxidation ◽  
Titanium Aluminides ◽  
Temperature Oxidation ◽  
Tial Alloys ◽  
Plasma Immersion Ion Implantation

Surfaces of titanium aluminides were treated by fluorine either physically using Plasma Immersion Ion Implantation (PI³) or chemically with a F-based polymer. By controlling the fluorination parameters, both treatments improve the oxidation resistance even in the presence of sulfur dioxide (0.1 vol%). No sulfur was detected in the oxide scale although thermodynamic calculations predict the formation of sulfides. The inward diffusion of oxygen and nitrogen in the alloy was found to be reduced in the presence of SO2.

Evolution kinetics and microstructure of MoSi 2 and Mo 5 Si 3 surface layers on two-phase Mo-9Si-18B alloy during pack-cementation and high-temperature oxidation

2004 ◽  
Vol 12 (4) ◽  
pp. 407-415 ◽  
Author(s):  
Kazuhiro Ito ◽  
Taisuke Hayashi ◽  
Masato Yokobayashi ◽  
Hiroshi Numakura
Keyword(s):  
High Temperature ◽  
High Temperature Oxidation ◽  
Pack Cementation ◽  
Surface Layers ◽  
Two Phase ◽  
Temperature Oxidation

The Use of Fluorine to Protect β-Solidifying γ-TiAl-Based Alloys against High-Temperature Oxidation

MRS Advances ◽  
2017 ◽  
Vol 2 (25) ◽  
pp. 1361-1367
Author(s):  
Alexander Donchev ◽  
Mathias Galetz ◽  
Svea Mayer ◽  
Helmut Clemens ◽  
Michael Schütze
Keyword(s):  
High Temperature ◽  
Titanium Aluminides ◽  
Elevated Temperatures ◽  
Turbine Blades ◽  
Nominal Composition ◽  
Hot Workability ◽  
Two Phase ◽  
Alumina Layer ◽  
Temperature Oxidation ◽  
Al Content

ABSTRACTLight-weight alloys based on intermetallic titanium aluminides (TiAl) are structural materials considered for high-temperature applications, e.g. in aero engines or automotive engines. TiAl alloys of engineering interest consist of two phases, the γ-TiAl and the α2-Ti3Al-phase. Recent developments have led to the so-called TNM alloys (T = TiAl; N = Nb; M = Mo) with an Al-content of 43.5 at.%. These alloys also possess the disordered body centered cubic β-Ti(Al)-phase at elevated temperatures, which ensures a better hot-workability compared to conventional two-phase alloys. However, the relatively low Al content (< 45 at.%) limits the high-temperature capability due to reduced oxidation resistance. This impedes their application in a temperature range above 800°C. The present work shows how the fluorine effect counteracts this disadvantage due to the formation of a protective alumina layer. The performance of the TNM alloy with the nominal composition of Ti-43.5Al-4Nb-1Mo-0.1B (at.%) is compared with another TNM alloy variant containing additional elements, such as Si and C, and the so-called GE alloy (Ti-48Al-2Cr-2Nb; at.%), which is already in use for turbine blades. The results of isothermal and thermocyclic high-temperature exposure tests of untreated and fluorine treated specimens will be compared. The effect of composition and microstructure of the alloys on the oxidation behavior with and without fluorine treatment are discussed.

Microstructures and Properties of Refractory Niobium-Silicide-Based Composites

2005 ◽  
Vol 475-479 ◽  
pp. 737-740 ◽  
Author(s):  
Shi Yu Qu ◽  
Ya Fang Han ◽  
Liguo Song
Keyword(s):  
Solid Solution ◽  
High Temperature ◽  
Phase Structure ◽  
High Temperature Oxidation ◽  
Multicomponent System ◽  
Compression Tests ◽  
Two Phase ◽  
Temperature Oxidation ◽  
Al Content ◽  
Oxidation Rates

The microstructures, mechanical properties and oxidation resistance of the refractory Nb-silicide-based composites have been investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD), compression tests and high-temperature oxidation experiments. The results showed that 1773K/100h heat-treatment was an optimum processing for acquiring equilibrium Nb solid solution and silicides microstructure. In the binary Nb-Si system, the microstructure consisted of continuous Nb5Si3 equilibrium matrix and dispersed Nb particles, while in the the Nb-Ti-Cr-Al-Si-(Hf) multicomponent system, there are two typical microstructures, i.e., a two-phase structure of β (Nb solid solution)+D81 Nb5Si3-type silicide in the alloys with the Si+Al content (15at.% and 6at.%, respectively), and a three-phase structure of β+D81 Nb5Si3-type + D88 Ti5Si3-type silicides in the alloys with lower Si+Al content (10at.% and 8at.%, respectively). The results of compression tests showed that all alloys display high strength at both room and high temperatures, only a slight decrease in compression properties occured for Nb-Ti-Cr-Al-Si alloys, comparing to the binary Nb-Si in-situ composites. This type of alloys possesses good high temperature strengths up to at least 1473K. The results of high-temperature oxidation experiments showed that the oxidation rates of the alloys with Ti, Cr, Al and Hf addition were at least one order of magnitude lower than those of the Nb-Si binary alloys.

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