Application of Cryogenic Coolants in Machining Processes : State-of-the-art Literature Study and Experimental Work on Metal Matrix Composite

Abstract: Conventional cutting fluids are known for being expensive, polluting and a non-sustainable part of modern manufacturing processes. Global industrial trends are leaning towards environmental and health friendly technologies. Cryogenic cooling is an innovative and sustainable method, capable of replacing conventional oil-based cutting fluids under various conditions. The method has already proved to have a great potential in many different machining setups, performing equally or better than conventional cooling strategies in all criteria concerning machinability. Majority of research work published about cryogenic machining has revolved around turning operations most commonly in combination with steels, nickel-based alloys and titanium-based alloys. Other machining operations, e.g. milling and drilling, are less researched leaving the field with a great amount of unexplored areas. Although the technology has been developing for more than 60 years the general knowledge on the subject among machining specialists is relatively low. The room for improvements is large and further optimization is necessary before more generalization of the technique within the industry. In the first part of this work a comprehensive state-of-the-art literature study is presented, with the main focus on turning, milling and drilling operations. Parallel to the making of the essay, a new search system within published work about cryogenic technology was designed and developed to create a database of knowledge for Sandvik Coromant in future cryogenic research. The second part of the essay covers the experimental work where tests were performed in drilling of metal matrix composite under different cooling strategies. The results revealed an advantage in the favour of CO2 cryogenic cooling concerning precision and surface finish but an obvious need for further optimization of the process was evident as well.