In-situ friction and fretting wear measurements of Inconel 617 at elevated temperatures

The objectives of this study were to investigate the effects of temperature (750 °C) on the coefficient of friction and wear rate of Inconel 617 in fretting wear in air and helium environments. An in-situ fretting wear measurement technique was developed to continuously monitor the change in wear depth during the fretting wear test. It was found that as the fretting wear progressed at room temperature and in air, the wear rate demonstrated a bilinear behavior including a severe running-in regime at the beginning followed by a mild steady state wear rate. The coefficient of friction decreased as the temperature was increased for both air and helium environments. In air environment, the wear rate decreased with increase in temperature. At 750 °C, helium environment showed more wear than in air environment. Scanning electron microscopy and energy dispersive X-ray spectroscopy were conducted to determine the morphology of the scar and relative proportion of oxygen on the specimens from both the helium and air environments. Oxides particles sintered to the contact surfaces were observed especially at 750 °C in air, which contributed to the lower friction and wear.