The mechanism in surface morphology of YSZ ceramics influencing its corrosion resistance to CMAS melt: Molecular dynamics research

Abstract

In this paper, several surface morphologies such as smooth style, or mesh & stripe style containing nanostructure were constructed and simulated by molecular dynamics simulation. The results show that the diffusion area of molten calcium-magnesium-alumina-silicate (CMAS) droplets on yttria-stabilized zirconia (YSZ) surface with stripe nanostructure is smaller than that on smooth or mesh style surfaces, and its contact angle obtains the largest value. The diffusion coefficient points out that the best corrosion resistance of YSZ surface comes from the lowest diffusivity of elements in molten CMAS on stripe nanostructure. Elements radial distribution function of Ca-O verified that they mainly keep in CMAS droplets instead of permeating into YSZ ceramics. And, the influence of nanostructure on the depth of Mg, Al, Si infiltration layer in CMAS is greater than that of Ca ion. Therefore, YSZ surfaces with stripe nanostructures exhibit the best corrosion resistance.