Enhancement of Groove Turning Performance by Additively Manufactured Tool Holders with Internal Cooling Channels and Combined Cooling Strategies

Abstract

Additively manufactured machining tools allow new concepts for internal cooling channels. Commercially available grooving tool holders with two connected channels carry fluids to the cutting zone and tool flank. This study compares commercial and newly designed tool holders. The new design provides two separate channels with the option to carry different media to the primary and secondary cutting edge. Different cooling strategies (flood cooling (FC), cryogenic cooling (LN2), minimum quantity lubrication (MQL), and combinations of them) were performed on the material Ti-6Al-4V (3.7165) to validate the performance and lifetime increase of the tool inserts. The test results show that the secondary edge cooling as well as combined cooling strategies reduce wear by up to 12 %. Neither LN2 nor LN2 combined with MQL are suitable for this process and tool design, but the combination of FC and MQL leads to a cutting length greater than 10000 m at 20 % higher productivity and the same reproducible surface roughness Rz of approx. 1 μm compared to commercially available grooving tool.

Keywords: Grooving, Cooling Lubrication Strategies, Laser Powder Bed Fusion (LPBF)