Modelling of Tool Life and Micro-Mist flow for Effective Micromachining of 316L Stainless Steel.

Recent technoligical advancement demands new robust micro-components made out of engineering materials. The prevalent methods of manufacturing at micro-nano level are established mostly for silicon structures. Therefore, there is interest to develop technologies for micro-fabrication of non silicon materials. This research studies microend-milling of 316L stainless steel. Machine tool requirement, tool modeling, cutting fluid evaluation, and effect of cutting parameters are investigated. A machine tool with high rigidity, high spindle speed, and minimal runout is selected for successful micro-milling. Cumulative tool wear and tool life of these micro-tools are studied under various cutting conditions. Ideal abrasive wear is observed when applying mist cooling whereas inter-granular shearing is the major failure mode while flood cooling or dry cutting during micro-machining. Various experiments and computational studies suggest an optimal position of the mist nozzle with respect to a tool that provides maximum lubrication at the cutting edge. Mist droplets effectively penetrate the boundary layer of a rotating tool and wet the cutting edge and significantly improve the tool life.