During the pantograph-contact wire current-carrying friction and wear process,the contact wire will produce different cross-sectional shapes,and the change of contact wire morphology may affect the contact relationship between the pantograph and the wire,and thus affect the current-carrying friction and wear performance between the pantograph and the wire.In order to study the effect of surface morphologies of contact wires on the current-carrying friction and wear properties of metal-impregnated carbon strips,the tests on the contact wire with conventional,pitted and slanted morphologies sliding against contact strips were carried out using a block-on-ring-high-speed current-carrying friction and wear test machine.The friction coefficient,arc energy,wear amount and surface morphology of the metal-impregnated carbon strips sliding against the contact wires with different morphologies were compared.The results show that under the passage of direct current,the friction pair composed of the conventional morphology contact wire and the metal-impregnated carbon strips has the smallest friction coefficient and the lowest wear of strip.The friction pair composed of the slanted morphology contact wire and the metal-impregnated carbon strips has the highest friction coefficient and the maximum wear of strip.〖HJ1.8mm〗The wear morphology of the metal-impregnated carbon strips was observed by a SEM microscope.It is found that the worn scar of the contact strips rubbing against the contact wire with conventional morphology is mainly characterized by oxidation wear,and more oxides are produced.The worn scar of the contact strips rubbing against the contact wire with pitted morphology is mainly characterized by ablation and abrasive wear,and small cracks,ablation pits,and more wear debris and peeling layers are produced.The worn scar of the contact strips rubbing against the contact wire with slanted morphology is mainly characterized by wire arc ablation,and large cracks,furrows,and more white globules are produced in the ablation area.Research shows that when the morphology of the contact wire changes,it can lead to increased wear of the strip and exacerbate the arcing discharge between the contacts,thereby deteriorating the contact state.Therefore,when the wear and deformation of the contact wire becomes severe,it should be replaced in time.