Study On Characteristics Of Deposition And Current-carrying Wear Behavior Of Electromagnetic Launch CuCrZr Rail

Aiming at the difference of deposition and microstructure along the launch direction on the surface of the electromagnetic launch CuCrZr rail,this study adopts the electromagnetic launch rail that has failed after service,disassembles it along the launch direction and studies the difference.At the same time,the actual armature and rail materials are used as friction pairs to explore the influence of the rail material repetitively on the tribological behavior and wear morphology of the armature material under current-carrying conditions.Scanning electron microscope（SEM）,energy X-ray spectroscopy（EDS）,X-ray diffraction（XRD）,photoelectron spectroscopy（XPS）,three-dimensional super-depth of field and electron backscatter diffraction（EBSD）were used to analyze the material surface and interface of the rail.The main contents and conclusions of this study are as follows:（1）The failed electromagnetic launch rail was sampled,and the characteristics of the deposition and the evolution process of the microstructure in different regions along the length of the rail were studied.The results show that there are obvious differences in the characteristics of the deposition.Electrical wear occurs in each area.The mechanical wear in area 1 is the most serious,and the typical characteristics of the deposition in area 2 are the most obvious.The inter-compound Al₄Cu₉,the thick deposition appeared cell-like dendrites formed by supercooling.A micron-scale diffusion layer is generated at the interface between the deposition and the rail,and the grain orientation of the deposition is perpendicular to the rail surface.（2）Using the actual Al alloy for the armature and the Cu alloy for the track as the friction pair,the friction and wear experiments under the electric-mechanical and thermal-mechanical conditions were carried out.The results show that under the repeated wear of the new armature Al alloy,the influence of adhesive wear is increasing,the material transfer tends to occur at the surface damage of the Cu alloy,and a very thin diffusion layer appears at the interface between the transfer layer and the substrate,and the electrical wear has a slight effect.The wear morphology is similar to the surface of the deposition.（3）The trend of friction coefficient under the conditions of electricity-mechanical and thermal-mechanical is very similar,showing a three-stage law,which can be summarized into the grinding-in stage,the iterate stage and the stable stage.The first grinding is the grinding-in stage;the second to sixth grinding is the iterate stage,during which Al transfer formation and peeling are frequently alternated,but the material transfer layer gradually stabilizes with the number of grindings;the seventh and eighth Grinding is a stable stage,in which the material transfer layer is basically stable,and the friction coefficient is stable and basically at the lowest level during the experiment.