Effect of REs (Y, Nd) addition on high temperature oxidation kinetics, oxide layer characteristic and activation energy of AZ80 alloy

The oxidation behaviors of AZ80, AZ80-0.32 Y and AZ80-0.38 Nd (wt.%) alloys were researched at 413 degrees C, 420 degrees C, 427 degrees C and 433 degrees C for up to 6h in air environment via a high precision analytical balance, a laser confocal microscope, differential scanning calorimeter (DSC) analysis, X-ray diffraction (XRD) analysis, scanning electron microscope (SEM) observation, and X-ray photoelectron spectroscopy (XPS) analysis. The results show that the weight gain and oxidation rate of AZ80 are reduced significantly, the initiation form and propagation of cracks in oxide layer are changed. Compact and protective oxide layer forms on alloy surface with Y or Nd addition. And the activation energies of AZ80, AZ80-0.32Y and AZ80-0.38Nd alloys calculated via Arrhenius equation are 82.556kJimol, 177.148kJ/mol and 136.738 kJ/mol, respectively. (C) 2020 Published by Elsevier B.V. on behalf of Chongqing University.