Electric Ablation Performance Of Copper Matrix Composites Under Vacuum

In order to study the effect of sliding electrical contact materials caused by materialproperties, current, contact force and environment pressure during the contact; theexperiment device of sliding electric ablation was put in vacuum chamber with100pa;and the sliding electric ablation research was carried out on the device with the electrodematerials of pure copper, Al₂O₃/Cu and C/Cu under different current and contact force.The mass of the electrode material was weighted before and after the ablation,the profileof the electrode material surface was plotted after the ablation, the macro-morphology theelectrode material surface was observed，the micro-morphology of the region of initial andsliding contact was scaned and its forming reasons were analysed, the changes of grain inthe cross-section of the working layer were discussed and its hardness was tested. Theexperimental results are as follows:From the mass loss, profile and contact voltage of electrode materials, the rule ofelectric erosion of the electrode materials becoming worse with the increase of current butbecoming better with the increase of the contact force under this experimental condition.the range of the mass loss of the three kinds of electrode materials are respectively0.5212-0.6647g（pure copper）,0.4137g-0.6414g（Al₂O₃/Cu） and0.3478-0.4137g（C/Cu）under300KA with different preload; the electrode material of C/Cu is better thanAl₂O₃/Cu at the performance of ablation resistance, and pure copper is the worst.Through the macro and micro morphology of the electrode materials after ablation,micro-bulge, micro-pore and crack mostly exist in the initial contact region on the surface;the splash existed around the initial contact region; the scratch lies in sliding contactregion. Pure copper has the most micro-bulge while C/Cu has the least; the micro-crack ofPure copper is largest while the micro-crack of Al₂O₃/Cu is smallest; the amount of splashand area of scratch range from more to less are respectively pure copper, C/Cu andAl₂O₃/Cu.The columnar grain structure appears in the cross-section of the working layer of pure copper and C/Cu under all experimental conditions through metallographic analysis,for Al₂O₃/Cu, while it only exists in the most serious ablation condition. The hardness inthe working layer of electrode materials were reduced because of the columnar grain.