Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1556559 | Journal of Materials Science & Technology | 2014 | 5 Pages |
Abstract
A β-NiAl alloy with normal purity, a S-doped and a Dy and S co-doped β-NiAl alloys were prepared by arc-melting and their corresponding S contents were less than 20 Ã 10â6, 33 Ã 10â6 and 22 Ã 10â6, respectively. The isothermal oxidation behavior of the alloys at 1200 °C was investigated and the extent of S segregation at the scale-alloy interface was determined by scanning Auger microscopy. S-doping had no significant effect on the phase transformation rate from θ- to α-Al2O3, while the addition of Dy retarded this process. For the S-doped alloy, scale rumpling occurred only after 2 h thermal exposure and numerous large voids were observed at the scale-alloy interface where S segregated. In contrast to this, the oxide scale formed on the Dy and S co-doped alloy still remained flat even after 50 h isothermal oxidation and only small voids existed at the interface where S segregation was not detected.
Related Topics
Physical Sciences and Engineering
Materials Science
Materials Chemistry
Authors
Lu Wang, Dongqing Li, Jian Chang, Hongbo Guo, Shengkai Gong, Huibin Xu,