Influence of Tin Content on Lattice Strain Energy Density, Hardness, and Wear Resistance in Fe–Sn Alloys

Abstract This study examines the role of Sn content (1, 2, and 4 wt%) on tailoring the microstructural evolution, strain energy density (SED), and tribological performance of Fe–Sn alloys, synthesized via mechanical alloying and hot pressing sintering. Leveraging SED as a strategic metric for alloy optimization, we employed X-ray diffraction and scanning electron microscopy to uncover a ferritic matrix with Sn-rich precipitates increasingly segregating at grain boundaries, achieving optimal uniformity at 2 wt% Sn. In situ tribological testing revealed this composition's exceptional wear resistance, driven by enhanced SED and hardness, which fortifies the alloy against sliding damage. In contrast, lower Sn content promoted plow-dominated wear via plastic deformation, while higher levels induced brittle spalling from grain boundary cracking. These findings underscore SED's potential as a design tool, illuminating a synergistic interplay between Sn-induced strain and microstructural stability that offers a novel framework for developing durable Fe-based alloys for wear applications.