Suppressing the Alpha-casing of Ti-alloys by a Combined Al-and F-treatment
Oxygen inward diffusion into standard Ti-alloys during high temperature exposure in oxygen containing environments leads to an oxygen enriched surface zone which is detrimental under mechanical load. Therefore, the operating temperature of these alloys is limited. An enrichment of Al in the surface zone of Ti-alloys leads to an improvement by the formation of intermetallic TixAly-phases with decreased oxygen solubility but this is not sufficient. Therefore, the combination of Al-enrichment in the surface zone to an extent that a TiAl-layer is formed and an additional F-treatment is proposed for the formation of a continuous stable alumina scale which prevents oxygen inward diffusion. In this paper the results of high temperature exposure tests in air of several Tialloys are presented without any treatment and treated with combined Al-enrichment plus fluorination. Post experimental investigations such as SEM revealed the formation of thin alumina layers on treated samples. Hardness measurements showed that no embrittlement was observed for the treated samples while untreated specimens showed increased hardness values corresponding with the oxygen diffusion profile in the subsurface zone.
Titanium fluorine effect high temperature oxidation
Alexander Donchev Michael Schütze Andreas Kolitsch Rossen Yankov
DECHEMA e. V. Karl-Winnacker-Institut Theodor-Heuss-AUee 25 D-60486 Frankfurt /Main,Germany Helmholtzzentrum Dresden-Rossendorf e. V. Institute of Ion Beam Physics and Materials Research Bautz
国际会议
The 12th World Conference Titanium(第十二届世界钛会 Ti-2011)
北京
英文
1864-1867
2011-06-19（万方平台首次上网日期，不代表论文的发表时间）