The effect of platinum additions on the oxidation of directionally-solidified Ni-Cr-Al-Y-Cr₃C₂alloys at 1,100 and 1,200°C

Beneficial Effect of Pt and of Pre-Oxidation on the Oxidation Behaviour of an NiCoCrAlYTa Bond-Coating for Thermal Barrier Coating Systems

“…According to the fluorescence spectroscopy results, Pt did not favour h-Al 2 O 3 formation. This is in agreement with the study of Stott et al [26] who found less transient alumina after oxidation of a Pt-containing Ni-Cr-Al-Y-Cr 3 C 2 alloy compared to the corresponding Pt-free alloy. But these results are in opposition with Quadakkers et al [23] who detected h-Al 2 O 3 within the TGO of Pt-modified NiCoCrAlY based TBC systems after 1000 h at 1000°C.…”

“…h-Al 2 O 3 was found with a-Al 2 O 3 within TGO, even after an oxidation of 1000 h at 1000°C. This contrasts with a study of Stott et al concerning Pt-modified directionally-solidified Ni-Cr-Al-Y-Cr 3 C 2 alloys [26]. After 2 h oxidation at 1100°C in dry oxygen, the oxide layer formed on the Pt-free alloy was mainly composed of h-Al 2 O 3 while a mix of h-Al 2 O 3 and a-Al 2 O 3 was observed on the Pt-modified alloy.…”