Particle Method Simulation for Formation and Flow of Cold Flakes in High-Pressure Die Casting

摘要

In high-pressure die casting (HPDC) processing of aluminum alloys, solidified layers generated in the sleeve of a die casting machine that flow into the mold cavity are known as "cold flakes." The prediction and control of them are a crucially important issue for HPDC. This study developed a method to simulate their formation and flow using smoothed particle hydrodynamics. First, a solidified layer was modeled as a set of solid particles with behaviors defined by mechanical constitutive equations. Second, this study proposed an algorithm for ascertaining the phase of particles and for calculating liquid-solid particle interaction. Numerical results demonstrated that the method can predict the formations of solidified layers in the sleeve, their peeling and folding during the plunger movements, their inflow into the runner and the mold cavity, and flow disturbances caused by solidified layers trapped at the gate.