Oxidation of Powder Metallurgy (PM) Ti鈥?8%Al鈥?%Cr鈥?%Nb鈥?0鈥?%)W Alloys Between 800 and 1000掳C in Air

Author:

Dong Yi Seo   Thuan Dinh Nguyen and Dong Bok Lee  

Journal:

Oxidation of Metals

Issue Date:

2010

Abstract(summary):

Three powder metallurgy (PM) TiAl alloys with a fully lamellar structure were oxidized isothermally and cyclically between 800 and 1000掳C in air in order to find the effect of W on the oxidation behavior of Ti–48Al–2Cr–2Nb alloys. The alloys oxidized parabolically during isothermal oxidation. Tungsten improved the isothermal and cyclic oxidation resistance. The oxide scales consisted primarily of an outer TiO₂ layer, an intermediate Al₂O₃-rich layer, and an inner TiO₂-rich layer. The alloying elements of Cr, Nb, and W tended to segregate in the lower part of the scale owing to their thermodynamic nobility. In the vicinity of the scale/matrix interface, TiN and Ti₂AlN coexisted.

Page:

145-156