Numerical Simulation of Liquid-Solid Extrusion Process Based on the Mechanical Model Coupled with Solidification

Liquid-solid extrusion process is a combined process of casting and extrusion which can be used to form tubes or bars directly from liquid metal. The performance of products is enhanced through the large deformation and the solidification under pressure with less shrinkage cavity or porosity. Numerical simulation of this process is hard to run for it involves mechanical modeling of the dynamic transition from liquid phase to solid phase. The liquid zone and solid zone were modeled independently for reasons of their different characteristics of deformation. The deformation of liquid zone was described according to the principle of element removal method which eliminates the elemental distortion during the simulation. The solidified zone under elevated temperature was modeled through the hyperbolic sine constitutive equation. The dynamic transitions from liquid phase to solid phase were determined based on the results of thermal analysis. The mechanical model coupled with solidification proposed in this paper was verified through the experiments of liquid-solid extrusion of LY12 alloy