Tool wear and cutting forces when machining inconel 718 under cryogenic conditions: Liquid nitrogen and carbon dioxide

摘要: Nickel-based superalloys are widely exploited in turbojets components which are subjected to intense thermal and mechanical loadings during their operation. In fact, they exhibit excellent mechanical properties over a wide range of temperature and high corrosion and creep resistance. However, these materials induce several problems related to the shaping by machining due to essentially high heat resistance, high hardening tendency, high chemical affinity with tool material and low thermal conductivity leading to very high temperature in the cutting zone. In this context, assisted machining processes aim to improve the productivity of certain materials that are difficult to cut. Indeed, in order to keep the tool cold, it has been proposed to use cryogenic fluids (liquid nitrogen LN2 and carbon dioxide CO2 as coolant for effectively reducing temperatures since their vaporization temperatures are equal to-196◦ C and-75◦ …