Zhang Changgeng, Liu Xiaoxiao, Jin Liang, Yan Rongge, Yang Qingxin
State Key Lab of Intelligent Power Distribution Equipment and System, College of Electrical Engineering, Hebei University of Technology, Tianjin 300401, China.
Hebei Key Laboratory of Equipment and Technology Demonstration of Flexible DC Transmission, College of Electrical Engineering, Hebei University of Technology, Tianjin 300401, China.
Materials (Basel). 2025 Jun 27;18(13):3060. doi: 10.3390/ma18133060.
The muzzle velocity of electromagnetic rail launchers approaches 1550 m/s, exhibiting typical hypervelocity electrical contact characteristics. During the electromagnetic launching process, extreme conditions, such as high current density, high temperature rise, and strong strain can cause wear on the surfaces of the armature and rail. Electromagnetic launch tests are conducted to study the wear conditions of the rail surface and the relationship between the wear state and contact resistance. After the rail is abraded by hundreds of launching armatures, its surface 2D profile and morphological characteristics are measured and analyzed. Based on fractal theory, the static contact resistance model is developed. Concurrently, the contact resistance at various positions is measured to reveal the evolution of the static contact resistance between the armature and the rail under wear. The research results show that along the direction of the armature launch, the rail surface wear transitions from mechanical wear to electrical wear, the fluctuation range of the 2D profile becomes smoother, and the roughness of the rail surface shows a decreasing trend. When the roughness is greater, the contact resistance is more sensitive to changes in external load.
电磁轨道发射器的初速接近1550米/秒，呈现出典型的超高速电接触特性。在电磁发射过程中，诸如高电流密度、高温升和强应变等极端条件会导致电枢和轨道表面磨损。进行电磁发射试验以研究轨道表面的磨损情况以及磨损状态与接触电阻之间的关系。在轨道被数百个发射电枢磨损后，对其表面二维轮廓和形态特征进行测量和分析。基于分形理论，建立了静态接触电阻模型。同时，测量不同位置的接触电阻，以揭示磨损情况下电枢与轨道之间静态接触电阻的演变。研究结果表明，沿电枢发射方向，轨道表面磨损从机械磨损转变为电磨损，二维轮廓的波动范围变得更平滑，轨道表面粗糙度呈下降趋势。当粗糙度较大时，接触电阻对外加载荷变化更敏感。
