Microstructure simulations of over-moulded metal micro-sized needles

Beside melt flow simulation in injection moulding the prediction of arising internal properties is essential to forecast final part properties. Crystallisation e.g. causes anisotropic structure set-ups in a moulded cross-section and affects the resulting global mechanical part behaviour. Nucleation and spherulite growth are complex processes going on during the cooling-down of semi-crystalline polymer melts. The knowledge of the final local structure set-ups and the degree of crystallinity is essential to predict the resulting mechanical part properties in future. Within the scope of the special research centre 370 (SFB 370) at RWTH Aachen University the software SphaeroSim was developed. It allows the online calculation of spherulite growth processes during the cooling of quiescent melts under injection moulding conditions. At present the software is operating two-dimensional using the Cellular Automata Method. In the past, only part cross-sections with different shapes were focused for simulation, but now it is also possible to consider micro-sized parts with a more complex geometry through a higher resolution of the geometry. Thus it is possible to visualise the going on crystallisation processes by the newly modified software considering new boundary conditions. In this paper simulation results are shown and interpretations to micro-parts properties will be pointed out.