Melt Characteristics of a Deposited Layer on Rail Surface under Different Contact Models for Electromagnetic Launching

Understanding the melting of the deposited layer is crucial for the armature’s melting process and sliding electrical contact performance. This study first establishes contact models for both the boundary lubrication state (BLS) and squeezed-film lubrication state (SFLS). A three-dimensional magnetic diffusion model is then constructed to simulate interface current distribution in these contact states. It is discovered that the maximum current density on the surface of the armature shows a decreasing trend as the thickness of the deposited layer grows. Then, a calculation model for the deposited layer’s melting thickness under BLS is developed. For SFLS, Reynolds and energy equations are used to construct models for liquid film thickness and the deposited layer’s melting thickness. The results indicate that the deposited layer’s melting thickness under BLS is significantly greater than that under SFLS. Specifically, the melting thickness decreases with launching displacement in BLS and increases under SFLS. In SFLS, the deposited layer’s melting can suppress armature melting, though it remains nearly equivalent to that observed with polished rail. These findings provide a foundation for deposited layer control technology, which is essential for enhancing sliding electric contact performance and launching efficiency.