Cyclic oxidation and rumpling behaviour of single phase β-(Ni,Pt)Al coatings with different thickness of initial Pt plating

Cyclic oxidation behaviour of single phase beta-(NLPt)Al coatings with different thickness of initial Pt plating was evaluated at 1100 degrees C in air. The coating sample of 5 mu m Pt showed the best oxidation resistance, and after oxidation a dual-layered structure of alumina scale was formed on this coating with precipitation of Pt-rich particles at both boundary and interior of columnar alpha-Al2O3 grains. Comparatively, the coating sample with 8 mu m Pt was prone to rumpling due to its lower hardness and Young's modulus, while the severer rumpling behaviour in turn increased the scale spallation tendency and Al depletion rate. (C) 2016 Elsevier Ltd. All rights reserved.