Microstructure, mechanical and tribological properties of SnS2/2024 Al composites prepared by powder metallurgy

Aluminum-based composites have great potential in aerospace, electromagnetic launch, and rail transit due to their low density and high specific strength. However, conventional aluminum alloys suffer from severe adhesive wear under high-load friction. In this study, layered solid lubricant SnS 2 was introduced into a 2024 Al matrix via powder metallurgy to develop self-lubricating composites with different SnS 2 contents (0-5.0 wt.%). The effects of SnS 2 on microstructure, mechanical properties, and tribological behavior were systematically examined. An optimal SnS 2 content (0.5 wt.%) enhanced sintering densification, refined grains, and improved interfacial bonding, yielding a tensile strength of 470 MPa and balanced strength-toughness. During friction, SnS 2 formed a stable lubricating film that reduced both the friction coefficient and wear rate. The 2.0 wt.% SnS 2 composite exhibited the best overall performance. These results demonstrate that SnS 2 is an effective self-lubricating phase for improving the wear resistance of high-strength aluminum-based composites.