Performance Evaluation of Additively Manufactured and Hybrid Indexable Milling Tools in Machining of AISI4140+QT and Ti-6Al-4V

Additively manufactured (AM) cutting tools enable new design concepts in tool development concerning lightweight construction, damping behavior, and internal cutting fluid supply. So far, the impact of the layer-by-layer manufacturing technique onto the tool performance during machining of aerospace materials is widely unknown. In this study, the performance characteristics of AM indexable milling tools were investigated and compared to a conventionally manufactured tool of the same geometry. The AM tools were manufactured by laser powder bed fusion (LPBF) from a newly developed bainitic steel alloy. All tools were analyzed with two main focuses. Outside the machine tool, geometrical characteristics and mechanical properties were taken into account. Inside the machine tool, during roughing of AISI4140þQT (42CrMo4þQT) and Ti-6Al-4V (ASTM Ti-Grade 5), tool wear, cutting forces, surface roughness and vibration behavior were evaluated. Three tool concepts were compared, a conventional tool, an AM tool, and a hybrid tool with a conventionally manufactured preform and an AM head. Differences in the performance behavior could be traced back mainly to geometrical inaccuracies caused during postprocessing of the tools. Thus, LPBF-manufactured basic bodies seem to meet the requirements as applications for indexable milling tools. Based on this work, future investigations using AM cutting tools can be carried out assuming a negligible influence of the manufacturing technique onto the tool performance during machining.