The cyclic oxidation behaviour of α-Cr+β-NiAl alloys with and without trace Zr addition

摘要

This study reports the cyclic oxidation behaviour of a series of Ni-Cr-Al alloys in still air at 1100 deg.C for up to 250 one-hour cycles. Each of the alloys had a β-NiAl+α-Cr microstructure with a similar α-Cr volume fraction, but different phase compositions. All of the alloys exhibited poor cyclic oxidation resistance, undergoing extensive scale spallation and internal oxidation. The scale morphology, weight-change kinetics, and maximum depth of internal oxide penetration were all very dependent on the aluminium content in the alloy.