Some brake pads of maglev train are always in the current-carrying state during service,resulting in increased material wear and affecting the service life of brake pads.In order to study the friction and wear properties of brake pad materials of medium and low speed maglev trains under current-carrying state,Copper-based powder metallurgy material for brake pads and Q235B material for brake discs were used as friction pairs,the friction and wear behavior of copper-based powder metallurgy/Q235B friction pair under different sliding speed was studied.The results show that when there is no current,the friction coefficient and wear rate show a downward trend as a whole with the increase of sliding speed.When there is current,the friction coefficient shows a downward trend as a whole with the increase of sliding speed,while the wear rate shows an upward trend as a whole.When there is no current,the worn surface of copper based powder metallurgy material is covered with an indigo-colored third body layer.The third layer is mainly granular at low speed,and is gradually compacted into a continuous dense shape with the increase of speed.At high speed,the continuous dense third body is broken due to the intensification of adhesive wear,resulting in the reverse growth of the friction coefficient and wear rate of the material.When there is current,there are two areas on the worn surface of Copper-based powder metallurgy material,which are mainly mechanical wear and arc ablation.The area dominated by mechanical wear is still composed of indigo-colored third body layer,while the area dominated by arc ablation is covered by a layer of gold molten material.With the increase of speed,the area of ablation zone is also gradually increasing.