Deep Drawing of Cylindrical Cups Using Polymer Powder Medium Based Flexible Forming

A novel flexible forming process-polymer powder medium based flexible forming (PPFF)-was presented in this research. Cylindrical cups with inner diameter of 8 mm were formed using rigid mould deep drawing and PPFF process, respectively. The blank material was pure copper C1100 with a thickness of 0.4 mm which was annealed at 450 degrees C for 1 h in vacuum condition. The deep drawing experiments were carried out at room temperature under dry friction condition. Ethylene-vinyl acetate copolymer (EVA), poly vinyl chloride (PVC) and ultra-high molecular weight polyethylene (UHWPE) were used. The influence of polymer powder type and weight on deep drawing force and limiting drawing ratio (LDR) were investigated. The results showed that the cylindrical cups were well formed by using PVC. The LDR reached 2.1 by using PVC, higher than rigid mould. The surface quality was also good, with the thinning rate much smaller than rigid mould forming.