Effect of Aging Treatment on the Interfacial Behavior and Microstructure Characteristics of Babbitt Alloy/Steel Interfaces Fabricated by Wire Arc Additive Manufacturing

Due to their unique oil‐lubricated friction‐reduction properties, tin‐based Babbitt alloys are essential for bearing wear‐resistant layers. The interfacial integrity between the alloy and the steel substrate is crucial for bearing durability. This study examines the interfacial evolution of wire arc additively manufactured (WAAM) tin‐based Babbitt alloy layers on 20# steel substrates under aging treatments. Using gas tungsten arc welding deposition combined with systematic thermal aging, the diffusion‐driven microstructural transformation at the Babbitt/steel interface is explored. The results show that extended aging greatly enhances Sn interdiffusion and promotes the formation of FeSn 2 intermetallic compounds, leading to a homogenized interfacial diffusion layer. Nanoindentation and Vickers hardness tests indicate that interfacial hardening increases with the duration of aging, along with a slight decrease in elastic modulus and fracture toughness. The optimal aging condition achieves a balanced interface enhancement, demonstrating the potential of WAAM combined with aging treatments to design high‐performance Babbitt/steel tribological interfaces for demanding bearing applications.