Numerical Simulation of Reoxidation Processes

Abstract

Reoxidation is one of the main problem accompanying the aluminium alloy casting process. The oxide layer created on the melt surface during reoxidation is entrained into the bulk of liquid metal and “bifilms” are created. Bifilms have negative impact on cast quality and internal homogenity of final casting. Paper aim is to clarify the reoxidation phenomenon by visualization with the aid of ProCAST numerical simulation software. Experiemtnal work deals with the design of several types of gating systems (non pressurized and naturally pressurized) with vortex elements in order to determine how these elements affect the reoxidation processes. Achieved results clearly confirmed the positive effect of the naturally pressurized gating system with vortex elements. The evaluation focuses mainly on melt velocity and amount of oxides created in gating system and in mold cavity.