Performance Evaluation of a Hybrid Cooling–lubrication System in Micro-milling of Ti6Al4V Alloy

Abstract

In this paper, a hybrid system was designed for cooling and lubrication in micro-milling of Ti6Al4 V alloy. This hybrid system is based on mixing the oil with chilled air. The effect of the hybrid system on cutting performance is evaluated in terms of tool wear and burr formation in the machining of Ti6Al4 V alloy. For cutting tests, an ultra-fine grained, uncoated carbide micro end mill with a diameter of 508 μm and K10–K20 grades was used. The efficiency of the designed hybrid system was compared with other cooling/lubrication methods (wet, chilled air, and MQL) and dry cutting conditions. The experimental results showed that the hybrid system gave the minimum tool wear and burr size. In addition, it was found that the chilled air with a lower temperature of –30°C led to chipping type damage on the cutting edge of the micro-tool.