Numerical simulation of surface turbulence and bifilms formation in aluminum low pressure die casting (LPDC

Effects of surface turbulence on surface oxide folding have been studied numerically. Bifilms are an unfavorable nucleation sites for volume defects such as cracks, gas bubbles and shrinkage cavities. Major parameter promoting bifilm formation is surface turbulence. This parameter could be characterized bysurface velocity exceeding a critical value. In this study Formation and distribution of bifilms were investigated precisely during mold filling using numerical simulation in an industrial aluminum (Al-7Si- Mg) casting filled by a low pressure die casting process. In a location where liquid metal falls and frontvelocity exceeded critical velocity double oxide films will be generated. Here liquid velocity along withdirection of vectors investigated to show the possibility of bifilms generation. A new model for simulation of bifilms formation and tracing has been used to inquiry where these defects accumulate

Keywords:

surface turbulence , bifilm , simulation , low pressures die casting