Influence of annealing on the CMAS corrosion behaviour of ytterbium disilicate environmental barrier coatings: A Raman imaging study

The study examined the CMAS corrosion behaviour of ytterbium disilicate EBCs using Raman imaging before and after annealing. Annealing transformed the coatings to crystalline, healing pores and cracks, and reducing corrosion depth and rate. Raman spectroscopy showed increased residual stresses with corrosion time, while sprayed coatings had lower stresses and higher susceptibility to damage. This research enhances the use of Raman spectroscopy in non-destructively characterizing EBCs degradation under CMAS conditions, offering insights for aeroengine combustion chamber design improvements.