Design and Validation of 3D-Printed Tools for Stamping of DP600

Abstract

This paper is focused on automotive stamping tools & dies and the impact of 3D metal printing on design and production of such tools & dies. Forming (U-bend) and trimming/cutting/blanking tools & dies designed both conventionally and by topology optimization were 3D-printed, using Laser-based Powder Bed Fusion (LPBF), in the maraging steel DIN 1.2709. These 3D-printed tools were then used to form (U-bend) and trim/cut/blank 2-mm thick hot-dip galvanized DP600. An approval of the forming tool required that 50,000 U-bends were formed in 2-mm thick DP600 without any surface scratches on the sheet metal part. An approval of the trimming/cutting/blanking tool required 100,000 trimming strokes with this tool, where the maximum (sheet metal) burr height was lower than 0.2 mm (lower than 10% of the sheet thickness (2 mm in this study)). The 3D-printed forming and trimming/cutting/blanking tools & dies - both the conventionally designed and the topology optimized versions – managed the criteria mentioned above and were therefore approved. The approval means that these concepts can now be used to make production stamping tools and dies. This paper describes the topology optimization, the forming & trimming/cutting/blanking testing, the results yielding an approval of the 3D-printed tool concepts, and the 3D-printed production tools for stamping of DP600.