Wear characteristics of armature surface and its thermal effects under different electromagnetic launch conditions

The surface wear characteristics of the armature passing through the rail are crucial as they relate to the quality of electromagnetic launch and the lifespan of the device. Charging voltage and initial surface roughness are significant factors influencing wear behavior. It is urgent to clarify the evolution of armature wear patterns and fundamentally suppressing material damage. Therefore, in this paper, an electromagnetic railgun experimental platform was established. LSCM measurement, SEM and EDS detection were performed on the surface of the post-launch armature, and the wear mechanism was analyzed in conjunction with the thermal effects and changes in contact resistance. The results show that as the charging voltage increases, the armature transitions from abrasive wear to oxidative wear and fatigue wear. For this work, the optimal charging voltage is 2100 V, with a wear rate of 0.38% and wear roughness of 8.46 μm. As the initial surface roughness decreases, abrasive wear, oxidative wear, and adhesive wear occur sequentially. The optimal initial roughness range is 0.55-1.05 μm, with a wear rate of 0.21-0.25% and wear roughness of 7.91-8.31 μm. During this process, both Joule heat and frictional heat continuously increase, with the former increasing more rapidly. There is an initial relatively large value of contact resistance, which fluctuates smoothly, and experiences a sharp increase when the armature exits the barrel, indicating the armature wear caused by the action of transition arc. Finally, a numerical model for armature wear is proposed, along with optimization directions for armature design.