Yおよび希土類元素添加TiAl合金の繰り返し酸化
1996 年 60 巻 10 号 p. 907-913
詳細
1996 年 60 巻 10 号 p. 907-913
Oxidation behavior of the intermetallic compound TiAl with additions of Y and REM (Ce, Nd, Sm, Tb, Dy) as third elements has been investigated at 1173 K in air by means of cyclic oxidation tests.
A small amount of Y addition restrains surface segregation of S and is effective for reducing spalling and breaking of oxide scale. The addition of a large amount of Y (2 mol%), however, increases an invasion of oxygen, and accordingly the mass gain by oxidation increases.
The addition of REM also restrains surface segregation of S, and leads to suppression of breaking and spalling of oxide scale, then the oxidation resistance is improved. However, the effect of REM addition to TiAl alloys is not so remarkable as that to Fe- and Ni-base alloys. This fact suggests that the scale spalling on TiAl-base alloys is controlled not only by S segregated at the scale-alloy interface, but also by other several factors
