金银纪念币, 压印成形, 缺陷预测, COINFORM

Flash line, light band and insufficient filling are the main defects in coining process for Au-Ag commemorative coins. Based on a special-purpose FEM software-COINFORM, numerical simulations for coinages were carried out. A radial friction power model was built for the prediction of light band defects. With the analysis of metal flow, the mechanism of flash line was studied on the basis of the experimental results. The former algorithm was improved that the simulation would stop only when the blank was fully contacted with the forming tools in all direction. The reaction force of blank at the stop time predicts the forming force in coining. Experimental results show that the predicted force is valid for eliminating insufficient filling.