Testing of milling cutter with the conformal cooling channels produced by the selective laser melting technology.

Additive manufacturing (AM) provides a wide range of applications such as cutting tool bodies fabrication. The high strength maraging steel M300 manufactured by Selective Laser Melting (SLM) method was thoroughly studied in regards of microstructure and mechanical properties. In particular, by SEM and TEM it was found that the microstructure contained numerous nano-precipitates after heat treatment, which corresponded to an increase of compressive yield strength by 31.4% and hardness by 54.3% in vertical direction. Based on the analysis a new concept of milling tool body, which possessed conformal cooling channels was design and manufactured by SLM. Finite element method (FEM) was performed to verify the designed milling tool body. The fabrication of the new milling tool body was followed by technological tests, and the results were compared with a conventionally manufactured milling tool body. The comparison was carried out in terms of face milling, slot machining and shoulder milling for different cutting conditions and machined materials. A further comparison was made in regards of the durability of the inserts used when machining different types of materials and the cooling. It was found that the 3D printed tool resulted to 20% longer tool life than conventional tool when using internal cooling. This study can be used in industry in case of designing special milling tool bodies, which may serve as an effective instrument for more intensive cooling of cutting inserts.