Experimental Study of Cu/Diamond Composite Electromagnetic Rail Ablation Characteristics

In the present work we investigated the ablation behavior of the Cu/diamond composite material under the current ranging from 100 to 300kA and the preload ranging from 0.4 to 2.0kN in the initial stage of the electromagnetic rail launch.The analysis reveals that, due to the dual function of the joule heat and electric arc heat, the mass loss and the ablation depth of Cu/diamond composite increase with the increase of the current and decrease with the increase of the preload; in the main ablation area, uneven topography is formed, and the exfoliation of the second phase particles causes a certain number of micro-pores, and thermal stress cracks are produced due to the strong alternating temperature field; micro-bulges and splash at the edge of the main ablation area are attributed to the molten liquid metal affected by the strong eddy current electromagnetic field; in the electrical sliding contact area, micro-scratches are formed due to the friction between the micro-bulges on the armature and the rail, and its wear mechanism is the abrasive wear; in the cross section of the ablation area of Cu/diamond composite, different scales of grains are formed corresponding to the different cooling rates resulting from the rails large length-height ratio, and the surface hardness of Cu/diamond composite undergoes a considerable decrease.