Comparative Study of High Speed Machining of Inconel 718 in Dry Condition and by Using Compressed Cold Carbon Dioxide Gas as Coolant

Difficult-to-cut materials like Inconel 718 are used for aerospace, steam turbine, bearing industry, nuclear and automotive applications. In machining, friction and heat generation at the cutting zone are the frequent problems, which affect the tool life and surface finish. Heat generation pose limitations during the turning of such modern materials due to their peculiar characteristics such as poor thermal conductivity, high strength at elevated temperature, resistance to wear and chemical degradation. A good understanding of the methods of lubrication/cooling at the cutting zone, reduction of heat generation will lead to efficient and economic machining of these modern materials. This paper presents use of compressed cold carbon dioxide for cooling at machined affected zone. Effect of cold compressed carbon dioxide as coolant on process forces, surface roughness, micro hardness, specific cutting pressure has been studied in comparison to dry turning for same set of cutting parameters.