Submerged micro grinding: a metalworking fluid application study

Micro machining with micro pencil grinding tools (MPGTs) is an emerging technology that can be used to manufacture closed microchannel structures in hard and brittle materials as well as hardened steels like 16MnCr5. At their current operating conditions, these tools have a comparatively short tool life. In previous works, MPGTs in combination with a minimum quantity lubrication (MQL) system were used to manufacture microchannels in 16MnCr5 hardened steel. The study has shown that steel adhesions clog the abrasive layer of MPGTs, most likely resulting from insufficient lubrication. In this paper, a metalworking fluid (MWF) supply method was developed to improve the process: a submerged micro grinding process, in which machining takes place inside a pool of MWF. In this study, the effect of seven types of MWFs on material adhesions at the bottom surface of the tool is evaluated. Equivalent good MWFs are then compared in a micro pendulum grinding experiment till failure.