Micro Quantity Internal Cooling (MQUIC™) of Cutting Tools for Increased Productivity While Machining Ti-6Al-4V

Machining of space age materials like Ti-6Al-4V is associated with thermally activated wear mechanisms which lead to rapid tool failure and increased machine downtime. The high strength and low thermal conductivity of Ti-6Al-4V can reduce tool-life significantly at high cutting speeds adding drastically to the per-unit cost. A new concept, Micro Quantity Internal Cooling (MQUIC™) has been developed to extend the tool-life and/or enable higher cutting speeds while machining Ti-6Al-4V. The concept involves introducing flow (coolant) in a micro-duct placed inside the tool and close to the cutting edge, thus bringing the cooling source close to the heat source (chip-contact area). In this research, experiments have been conducted to compare the performance (wear rates) of cutting tools using the MQUIC™ concept with those run under dry or flood conditions. Further, two levels of feed and cutting speed are selected for the experiments so as to be able to investigate the combined effect of parameters on tool performance. Physical testing employing coolant consumption of less than 5% of typical flood coolant rates proves the viability of the concept by demonstrating wear rates of 1/3 to 1/2 those of flood cooling. The testing also proves the application of the MQUIC™ concept to enable higher cutting speeds than the current industry standard for machining Ti-6Al-4V. This paper presents the experimental setup, methodology and results obtained while testing the feasibility of the concept.