Correlative atom-probe tomography and transmission electron microscope study of a chemical transition in a spinel on an oxidized nickel-based superalloy

• DOI: 10.1016/j.scriptamat.2013.02.025
• Publication Date: 2013-02-22T22:11:38Z
• Authors: Sung-Il Baik; Xin Yin; David N. Seidman
• Keywords: 0103 physical sciences; 01 natural sciences

Complex thermally grown oxides (TGOs) are formed on a single-crystal Ni-based superalloy due to a large fraction of alloying elements. Combining atom-probe tomography and transmission electron microscopy analyses, the three-dimensional elemental distributions of metal oxides of the spinel and refractory metal-oxide regions are presented. A spinel-type oxide, Ni(Cr,Al) 2 O 4 , is formed with a crystallographic orientation relationship with the alloy substrate, which decomposes into other oxides. The sequence of oxides observed in the TGO are NiO → Cr 2 O 3 → Ta 2 O 5 → NiTaO 4 , NiTa 2 O 6 → Ni(Cr,Al) 2 O 4 → Al 2 O 3 .