Effect of Milling on Fretting Wear Performance of GH4169 Superalloy

Abstract

GH4169 superalloy is a commonly used material in aero-engine. With high strength, high hardness, high work hardening, and low thermal conductivity, it is a typical hard-to-cut material. Selection of the appropriate machining process and cutting parameters is particularly important for its fretting wear performance. In this study, GH4169 superalloy was machined by milling, and the surface integrity and fretting wear properties were investigated at four different cutting speeds. The results indicate that a larger degree of work hardening, and a greater degree of plastic deformation occur with increasing cutting speed. Upon reaching 300 and 400 m/min of cutting speed, the white layer is formed on the surface by the coupling of the plastic deformation mechanism and the phase transformation mechanism. Milling did not change the wear mechanism of the GH4169 superalloy, the primary wear mechanisms are oxide and abrasive wear. Because of the formation of the work hardening layer, the wear resistance of the GH4169 superalloy has increased due to milling. The GH4169 superalloy exhibits the greatest wear resistance at a cutting speed of 200 m/min. Due to the formation of a white layer, the wear resistance of GH4169 superalloy decreased at 300 m/min and 400 m/min cutting speeds compared to 200 m/min, and at 100 m/min cutting speed, the smallest improvement in wear resistance was observed.

Keywords: GH4169 superalloy, Milling, cutting speed, Surface integrity, Fretting wear