|About this Abstract
||2017 TMS Annual Meeting & Exhibition
||Defects and Properties of Cast Metals
||Modeling of Mechanical Properties of Al Oxide Films Using Molecular Dynamics
||Jialin Liu, Qigui Wang, Yue Qi
|On-Site Speaker (Planned)
Alumina films form instantaneously when fresh liquid aluminum is exposed to air. During casting, alumina thin-film (~2nm) can be easily entrained into final product due to turbulence and folding mechanism. The buried alumina films play significant roles in porosity and microstructure formation during solidification and thus the final mechanical performance of cast products. This paper reports the formation and mechanical properties of alumina using molecular dynamics with reactive force field. The formation history was mimicked by simulating oxidizing liquid aluminum at elevated temperature then cooling to room temperature. The mechanical properties of thin-film and bi-film with different formation history were compared. The results showed nanoscale alumina thin-film behaves ductile during deformation. The flow stress of thin-film is proportional inversely to thickness due to surface Al-O bond realignment. The Al/O-ratio affects the bi-film formation at metal/oxides interface. This work provides insights into the actual impact of alumina bi-film on casting products.
||Planned: Supplemental Proceedings volume