Selective oxidation of aluminium in Mo(Al,Si)&lt;sub&gt;2&lt;/sub&gt;

Ding, Z.; Brouwer, J.C.; Kwakernaak, C.; Hermans, M.J.M.; Popovich, V.; Quadakkers, Willem J.; Sloof, W.G.

doi:10.1016/j.corsci.2022.110884

Selective oxidation of aluminium in Mo(Al,Si)₂

Title

Selective oxidation of aluminium in Mo(Al,Si)₂

Author

Ding, Z. (TU Delft Team Marcel Hermans)
Brouwer, J.C. (TU Delft Team Marcel Hermans)
Kwakernaak, C. (TU Delft Team Maria Santofimia Navarro)
Hermans, M.J.M. (TU Delft Team Marcel Hermans)
Popovich, V. (TU Delft Team Vera Popovich)
Quadakkers, Willem J. (Forschungszentrum Jülich)
Sloof, W.G. (TU Delft Team Kevin Rossi)

Date

2023

Abstract

Mo(Al_xSi_1-x)₂ alloy with x in the range of 0.35–0.65 were prepared by a one-step spark plasma sintering. To study the exclusive formation of an α-Al₂O₃ scale, oxidation experiments were conducted in low and high oxygen partial pressure ambient at 1373 K; viz.: 10⁻¹⁴ and 0.21 atm. The oxidation kinetics follows a parabolic rate law after a transient period. A counter-diffusion process of O and Al along grain boundaries of Al₂O₃ scale is responsible for the equiaxed and columnar grain growth based on a two-layered microstructure. The formation of a dense equiaxed α-Al₂O₃ layer contributes to excellent oxidation resistance.