A Case Study on Metal-Ceramic Interfaces: Wetting of Alumina by Molten Aluminum

Abstract

Interfacial behavior of Al and α-Al2O3 are investigated via molecular dynamic simulation (MD) employing reactive force fields parameterized for Al and Al2O3. The main result of this work is elucidating the wetting behavior and interface chemistry of molten aluminum on the α-Alumina (0001) surface through MD simulations. Wetting and interface chemistry are studied at 8 different temperatures from 700 to 1400 K for four different droplet sizes: with 16, 24, 32 and 40 Å diameters. Chemical reactions are observed at all temperatures and sizes in addition to diffusion between droplet and substrate atoms into each other during the wetting process. To define the level of wetting, we characterized contact angles of aluminum droplets on alumina substrates for all temperatures and sizes by using a method developed by Hautman and Klein. Chemical reactions are more extensive for the small droplets (16 and 24 Å) due to their larger surface to volume ratio in comparison to the larger droplets (32, and 40 Å) of droplets.

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

“…The present results are consistent with previous computational and experimental studies of the wetting process. For example, recently, Tigli et al employed ReaxFF reactive MD simulations to investigate the wetting processes in an Al and alumina system [34]. They revealed that some of the oxygen atoms diffused into the molten Al droplet within a range of 10 Å, which indicated that the solubility limit of oxygen in liquid Al droplets was very limited.…”