中文摘要：

电磁轨道发射中，电枢与导轨间的滑动电接触状况直接影响发射效果和身管寿命。为此对发射过程中滑动电接触特性开展了研究，探寻改善电枢与导轨接触界面接触状态的方法。在充电电压和放电时序相同的条件下，将铝电枢分别在T2紫铜、H62黄铜、6061铝合金3种材料导轨上进行发射试验，测量炮口电压和电枢电流并进行分析，得到不同接触材料间的接触电阻曲线。通过对比分析曲线，得到电枢与不同材料导轨间的接触状况及转捩规律。结果表明：在上述3种试验条件下，所有接触电阻曲线具有相似的变化趋势和转捩特点，而且铝电枢与铝导轨间的电接触性能最佳，接触电阻最小且发射后的导轨表面状态最好。根据转捩经常发生于电流下降至峰值电流80％～90％的时刻的特点，采用提高驱动电流的大小，使电枢在此之前出膛的方法，能有效避免转捩发生。

英文摘要：

In electromagnetic railgun launches, the situation of sliding electrical contacts between armature and rails is abominable and directly related to the launch effect and influences the barrel life. We studied the properties of sliding electrical contacts so as to explore methods to improve the contact states, and designed experiments of aluminum armature sliding respectively on three different material rails. During the launch, the current in the rails and the muzzle voltage were measured, and painstaking was analyzed. Variation rules of the contact resistance between the different contact materials were obtained, contributing to the profound understanding of the process of sliding electrical contacts. It is revealed that transition often occurs when the current drops to 80%-90% value of the peak current, but transition will disappear if the armature flies out earlier. Electrical contacts of aluminum to aluminum have the best performance, owing to minimal contact resistance and best states on the rail surfaces after launching.