High-Temperature Friction and Wear Features of Nickel-Based Single Crystal Superalloy

The nickel-based single crystal (NBSC) superalloy has been widely used in aero engines, gas turbines, and other power plants due to its excellent high-temperature performance. During the working process, wear often occurs on the contact surface of the NBSC superalloy, which will promote crack nucleation and reduce its working life. In this work, the dry-sliding friction and wear behaviors of NBSC superalloy with < 001 > crystallographic orientation at different temperature and loading conditions are investigated by using a ball-on-disc tribometer. Results show that both the friction coefficient and wear rate of the NBSC superalloy are high at room temperature, and both them are significantly reduced as the temperature rises to 600 degrees C and 700 degrees C. Analysis of the worn morphologies and cross-section SEM micrographs shows that a compacted glaze-layer is formed at high temperatures like 600 degrees C and 700 degrees C during the early stage of wear process, acting like a lubricant between the superalloy and rubbing ball. Hence, the change in wear mechanism caused by temperature leads to significant change of wear behaviors. In contrast to temperature, the magnitude of load has less effect on the wear mechanism. [GRAPHICAL ABSTRACT].