Experimental research on cryogenic cutting performance of Ni-based superalloy GH4169

Ni-based superalloy GH4169 is widely demanded in the aerospace industry because of its excellent properties. However, the cutting of GH4169 at normal temperature has many challenges, such as tool wear, machining accuracy, and production efficiency. Cryogenic cutting has been an advanced method in assisting material removal machining. This paper focused on the cryogenic cutting performance of GH4169 at different initial temperatures, namely, 20 °C, −30 °C, −80 °C, and –130 °C. Firstly, the cryogenic mechanical properties of GH4169 were obtained by the Hopkinson pressure bar test at speed of 12 m/s and 18 m/s. The obtained data was used to analyze the cryogenic cutting performance of GH4169 at evaluated temperatures. The single factor milling experiments of GH4169 were carried out at room temperature and evaluated cryogenic levels, and the cutting performance in terms of cutting chips, cutting forces, and tool wear was investigated. The results showed that cryogenic cooling at −130 °C could increase the shear yield strength of the GH4169 by around 19.80% and the length of the cutting chip decreased monotonically by 53.45% compared with the length at room temperature. However, the cutting forces were not monotonically decreased. The cutting forces increased with the decrease of temperature when the initial temperature varied from 20 to −80 °C. However, when the initial temperature further dropped to –130 °C, the cutting forces were reduced by 30.60% for Fx, 24.02% for Fy, and 16.15% for Fz, respectively. Similarly, tool wear at the rake face and flank face is the most severe at –80 °C and the least at –130 °C. The average wear bandwidth at room temperature is 92.06 μm and decreases to 83.358 μm at –130 °C, which is reduced by 9.45%.