Three-Dimensional Numerical Simulation of Multi-phase Flow of Powder Injection Moulding Filling Process for Intricate Parts

Powder injection molding filling process was considered as a powder, binder and air multi-phase flow process. The multi-phase flow governing equations of powder injection molding filling process were given. According to the actual parameters of iron powder injection molding filling process for intricate parts clamp, the initial and boundary conditions of the governing equations were determined. A three-dimensional numerical simulation of multi-phase flow in iron powder injection moulding filling process was performed using the computational fluid dynamics software CFX, for the no slip boundary condition employed at the wall of the clamp. The velocity streamlines of powder in the filling process were estimated. The transient distributions of temperature, pressure, and their development in the moulded part were simulated. The temperature and pressure versus time curves for different positions in the mold cavity were simulated. The transient distributions of powder volume fraction for different moments in the filling process were analyzed. The reasons for the powder binder separation during the injection moulding process or the density gradients in the component can be analyzed by the simulation results. The numerical simulation provides a visual analyzing method for investigating the causes of the defects occurring in injection molding products.