Comparison of cryogenic cooling strategy effects on machinability of milling nickel-based alloy

Abstract

Liquid nitrogen (LN 2 ) cooling can play a green manufacturing role for nickel-based alloy materials, and it is credible for industrial applications and being popularized. A predict model of LN 2 consumption was established considering cooling effect. Meanwhile, a series of processing tests were executed including in flood, LN 2 external spray and LN 2 inner injection cooling strategies. The different cooling effects on the machining accuracy, required LN 2 flow and tool wear were investigated for 3 cooling strategies in detail. The results show that the cutting temperature is more than 400℃for flood cooling, but it is less than 0℃ for LN 2 ones at high speed. Moreover, the inner injection strategy can economize more LN 2 consumption compared with external spay one. When the cutting zone is required lower cooling temperature, LN 2 consumption of inner injection is less half than that of external one. Besides, the tool durability and workpiece processing performances of LN 2 cooling are all increased than flood one. In contrast to flood cooling, the tool life based on LN 2 cooling can be improved about 1 time. In addition, compared with LN 2 external spray, the inner injection cooling has more than 5 min extension at high speed as well as 10 min at low speed. Furthermore, LN 2 inner injection has also a weaker impact on the alloy microhardness and cutting force. Therefore, the study can confirm that LN 2 inner injection cooling strategy is advantageous compared with external spray for LN 2 cooling application.