Numerical simulation of filling process on casting in micro scale

The filling process of micro-gear casting with Zn-4Al alloy was simulated by applying the modified traditional Navier-Stoke equation and the Fluent software. The results show that the alloy is not horizontal expansion and keeps the initial state when the liquid metal is flowed into the cavity of micro-gear and passes through parts of gear plate by the effect of inertia. Liquid metal is anti-filled into the tooth parts outside gear by impacting posterior of cavity, resulting in the second pressure head. Many micro-bubbles are created after the gas in the cavity is mixed and cut by high-speed movement of the metal liquid, and then brought into the mainstream areas and excluded from the exhaust ports.