TRIBOLOGICAL ANALYSIS OF METAL SURFACE WEAR USING A BALL-SCALE ASSESSMENT METHOD UNDER DIFFERENT LOADING CONDITIONS

Abstract

The reliability and service life of mechanical systems are largely determined by the wear resistance of their contacting surfaces. Accurate assessment of wear processes is essential for improving the performance of machine elements operating under friction conditions. This study presents an experimental and theoretical investigation of metal surface wear under different normal loads using a ball-scale assessment methodology. Twenty metallic specimens were tested under loading conditions of 0 N, 1 N, 2 N, and 5 N. Microscopic images of the worn surfaces were analyzed and compared with a reference specimen. Wear severity was quantified using a ten-point ball-scale system and interpreted through Archard’s wear model, Greenwood–Williamson contact theory, and Kragelsky’s energy-based wear concept. The obtained results indicate that wear intensity increases with applied load and gradually transitions from predominantly abrasive wear to a combined abrasive–adhesive wear mechanism. A predictive mathematical model and a three-dimensional wear surface were developed for extrapolation of wear behavior at higher loads. The proposed methodology provides a practical tool for tribological diagnostics and wear prediction in engineering applications.