Numerical and experimental study on effect of process parameters on preparation of A356 aluminum alloy semi-solid slurry by electromagnetic stirring

Abstract

A two-dimensional model coupling of the electromagnetic field, the temperature field and the flow field of preparation of A356 aluminum alloy semi-solid slurry by electromagnetic stirring (EMS) was established. The Power Law Cut-Off (PLCO) model was used to model the semi-solid slurry. The effect of process parameters such as stirring frequency, stirring current, pouring temperature and crucible preheated temperature on the electromagnetic field, temperature field and flow field were investigated by finite element code ANSYS combined with secondary development INTEL FORTRAN software and corresponding experimental verification. The results show that the electromagnetic field and flow field increase as stirring frequency and stirring current increase. Similarly, temperature field and flow field increase as pouring temperature and crucible preheated temperature increase. However, too high stirring frequency, stirring current, pouring temperature and crucible temperature may lead to rapid increase in the flow field, as a result, strongly turbulent flow might occur. The reasonable process parameters for preparation of A356 alloy semi-solid slurry by EMS were obtained. The simulation results are significantly approved with corresponding experimental ones, that verifying the reliability of the calculation models and the software algorithm.

3D Numerical and Experimental Investigation on Semi-Solid AlSi9Mg Alloy Slurry Prepared by Electromagnetic Stirring

“…( 4) and exported to FLUENT solver as a momentum source term by a user-defined function (UDF). In addition, the PLCO viscosity model [17][18][19] was programmed in UDF and loaded on the model. The volume of the fluid model was used and the wall was viewed as a stationary wall under a no-slip shear condition in FLUENT.…”

“…Hence, an appropriate viscosity model should be used to describe the variation in viscosity, which depends on slurry temperature and shear rate. The PLCO model is a modified one-phase power-law model with a shear cut-off, which can be used during EMS and the constitutive equations are shown as follows [17][18][19].…”

Microstructural Investigation of Semisolid Aluminum A356 Alloy Prepared by the Combination of Electromagnetic Stirring and Gas Induction

“…Therefore by eliminating the central part, the magnetic and temperature fields were more uniformly distributed in this narrow gap and thus a more uniform structure is obtained. A two-dimensional computational model of EMS has also been developed by Vanluu et al [9] to investigate the effects of process parameters on temperature and flow fields. They concluded that increasing stirring frequency and current will increase electromagnetic field and flow field density, but will not cause a uniform distribution of grains.…”

Application of Radial Forging and Remelting Treatment to Prepare Semi-Solid Billet of AlMg0.7Si Alloy

“…It includes preparation of semi-solid billet and forming steps [3]. Until now, in addition to magneto-hydrodynamic (MHD) stirring [4], cooling slope casting [5], liquidus/near liquidus casting [6], and strain-induced melt activation (SIMA) [7], recrystallization and partial melting (RAP) [8] is also a promising technology for preparing semi-solid billet.…”