The Fluorine Effect for High Temperature Oxidation Protection of TiAl-Alloys for Automotive and Aero-Engine Applications


The Fluorine Effect for High Temperature Oxidation Protection of TiAl-Alloys for Automotive and Aero-Engine Applications

Donchev, A.; Kolitsch, A.; Möller, W.; Schütze, M.; Yankov, R. A.

The insufficient oxidation resistance of TiAl-alloys above roughly 800°C is a major disadvantage for their use in several high temperature applications. This problem can be overcome by small amounts of halogens in the surface zone of the TiAl-material. Especially fluorine has proven to be a beneficial doping element. The fluorine effect is stable at least for one year at temperatures up to 900°C under thermocyclic conditions. Results of fluorine treated and untreated TiAl-coupons, more complex samples and real components are shown in this paper. The specimens were exposed isothermally and thermocyclically in the temperature range from 700 – 1050°C in laboratory air or synthetic air. The specimens can be treated with fluorine in several ways e.g. spraying or ion implantation. Without any treatment some samples were heavily destroyed during high temperature oxidation but after fluorine treatment the components were still intact. Post oxidation investigations revealed the formation of a thin and protective Al2O3-scale confirming the fluorine effect.

  • Lecture (Conference)
    The Minerals, Metals & Materials Society Annual Meeting, 09.-13.03.2008, New Orleans, USA

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Publ.-Id: 12092