Product development based on metal 3D printing has been expanding steadily in the manufacturing industry. Powder bed fusion (PBF) is currently the most widely used metal 3D printing method, as it produces parts of complex shape with high precision. Applying PBF to the cutting tool industry could shorten process time relative to conventional sintering routes and reduce the material waste generated during machining. It also allows internal lattice structures and fluid channels to be designed within the tool, facilitating light-weighting and improved cutting performance. In this study, nTop software was first used to design the internal lattice structure of an end mill tool for additive manufacturing and to perform the corresponding simulation analysis. Three configurations were compared, in which the tool lattice was defined either by thickness dimension or by thickness range, and the reinforced results confirmed that none of the designs posed problems for actual additive manufacturing within the software. On this basis, tool bodies were fabricated on PBF metal 3D printing equipment, and their feasibility for tool applications was evaluated.

Heat treated die steels are durable and resistant to abrasion. However, machining them is not very efficient. To improve the machinability using the end-milling process for high hardness die steels, we proposed an end-mill shape through analysis of the cutting force and simulation. In this study, we determined the important factors affecting the cutting force among several elements of end-mill shape using the customized cutting simulator and the design of experiments (DOE) technique. After the selecting the effective factors based on the simulation and DOE results, various end-mills were fabricated by adjusting the parameters. In the experiment, the cutting force between 1 pass and 40 pass were measured and the average value compared with each end-mill shape. Edge radius, radial relief angle and axial relief angle were selected as a key parameters and optimized by measuring the cutting force through repeated and well controlled experiments. In conclusion, the effective factors were confirmed and we could now determine the optimum shape of end-mill to minimize the cutting force for high hardness die steels.