DETERMINING THE TOOL LIFE OF A CEMENTED CARBIDE DRILL USING OPTIMIZED PROCESS, DELIVERY SYSTEM, AND DRILL DESIGN PARAMETERS IN DEEP HOLE DRILLING USING ENVIRONMENT FRIENDLY MACHINING METHOD

Near dry machining or Minimum Quantity Lubrication (MQL) methodology appears to be a valid solution to meet environmental challenges of metal removal processes. However, in order to implement environmentally friendly machining into high production manufacturing environments, it is imperative to invent a robust solution for a wide variety of machined features. In previous work by the authors, capabilities of the MQL process, calibrated for machining extremely deep holes with length to diameter (LID) ratio of up to 15, were proven. An optimal machining solution was developed using the Box and Behnken experimental design approach, and it was demonstrated that cemented carbide drills with proper cutting geometry and MQL settings can be used for deep hole drilling of aluminum. This work, focused on developing a production ready application, proved that MQL technology is also robust enough to achieve adequate tool life for high volume manufacturing requirements. It actually exhibited that such approach may even exceed tool life requirements currently enforced for conventional processes using gun drills or G-drills. In addition, machining time was significantly reduced with this innovative technology achieving productivity approximately 7 times higher than in traditional drilling operations. Considering these achievements, MQL has been demonstrated to be the drilling technology of future that will help reducing capital investments into production machinery and minimize landfill discharges of high production manufacturing facilities.