Reactive wetting of metallic/ceramic (Al/α-Al2 O3 ) systems: a parallel molecular dynamics simulation study

Authors : Gürcan ARAL

Pages : 24-38

View : 15 | Download : 6

Publication Date : 0000-00-00

Article Type : Research Paper

Abstract :The reactive wetting process of a flat solid alumina insert ignore into journalissuearticles values(α-Al2 O3); ceramic surface by metallic aluminum insert ignore into journalissuearticles values(Al); nanodroplets with different shapes insert ignore into journalissuearticles values(spherical, cylindrical, and layer); is studied using parallel molecular dynamics insert ignore into journalissuearticles values(MD); simulations based on a variable charge MD method, with focuses on heat transfer, mass transfer, and the structure of the reactive region at the Al/α-Al2 O3 interface. We find that the diffusion of oxygen insert ignore into journalissuearticles values(O); atoms from the substrate into the droplet leads to the formation of a continuous layer of reaction product at the interface. The diffusion length of oxygen atoms into the spherical Al droplet is found to be ~7.3 Å, and the number density of O atoms at the ~5 top layers of the substrate decreases substantially. As a result, the structural correlations near the reactive region differ considerably from those in the solid substrate. Heat generated by the exothermic reactions in the reactive region is transferred to both the substrate and the droplet. The heat transfer is found to be sensitive to droplet shape.
Keywords : Variable charge method, molecular dynamics simulations, wetting, alumina, aluminum