A Novel High-Fidelity Tribometer to Investigate the Tribological Performance of Variable Stator Vane Shaft–Bushing Components

Abstract The variable stator vane (VSV) is a specialized component in aerospace engines, and unclear wear mechanisms in its internal shaft–bushing system could potentially jeopardize flight safety. To explore the tribological performance of VSV shaft–bushing components under high-temperature conditions and ensure the operational safety of the engine, this study developed a high-fidelity tribometer based on modular design principles. This device effectively controls high temperatures, axial and radial loads, and reciprocating oscillatory motions. Owing to its modular architecture, the tribometer can be readily reconfigured to accommodate shaft–bushing pairs of various geometries and sizes, making it suitable for future testing of diverse VSV shaft–bushing designs and materials. Under the test condition of 250 °C and 50 N, the tribometer operated stably for a long duration (71 h) with smooth and steady signals, confirming the reliability of the system. In addition, a standardized posttest workflow (sectioning–cleaning–drying–scanning electron microscopy (SEM)/energy-dispersive spectroscopy (EDS)) was established and demonstrated using an IN718 shaft–bushing pair with a WC–Co coating. The results show that the tested shaft–bushing specimens exhibit clear and consistent wear morphologies after the friction and wear tests, providing a general experimental platform and methodology to support future wear mechanism studies and design screening of VSV shaft–bushing pairs.