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目的：有效解决利用喷射电沉积在直流电流下制备的复合镀层存在的镀层表面粗糙，尤其当硬质颗粒尺寸达到微米级时，表面恶化程度尤为严重的问题。方法将换向脉冲电流取代直流电流应用于喷射电沉积，制备颗粒尺寸达到微米级的Co-Cr3C2复合镀层，通过分析复合镀层组织形貌、硬度和耐磨性等，探讨换向脉冲电参数对复合镀层颗粒复合量、镀层表面粗糙度以及镀层性能的影响，并对其影响机理进行分析。结果在保持颗粒较高含量复合的同时提高镀层表面平整度，通过控制脉冲电参数，制备出复合微米级Cr3C2颗粒平整、颗粒质量分数为11%的Co-Cr3C2复合镀层。结论 Cr3C2颗粒的复合量越高，镀层性能越优异，但镀层表面也更加粗糙，换向脉冲电流的反向过程可发生共沉积的逆过程，利用脉冲电流不仅对复合镀层起到整平的作用，同时可以提高颗粒在复合镀层中分散的均匀性，使复合镀层的表面形貌以及性能均得到明显改善。

ABSTRACT:Objective To efficiently solve the problem that the coating surface prepared by DC jet-electrodeposition is quite rough, and the surface deterioration degree is particularly serious when the hard particle size reaches micron grade.Methods Reverse pulse current was applied in jet-electrodeposition instead of DC to prepare the Co-Cr3C2 composite coatings which the size of Cr3C2 reaching micron grade. Through analyzing the composite tissue morphology and testing hardness, wear resistance and other perfor-mance parameters, the effect of commutation pulse electrical parameters on the composite coating particle composite coating, the roughness of the coating and the coating performance were discussed, and the influencing mechanism was analyzed.Results Using pulse current to prepare Co-Cr3C2composite coating could improve the surface roughness while maintaining higher concentration of the particles. By controlling the pulse electric parameters, micron grade Co-Cr3C2 composite coating with particle content of up to 11% was prepared.ConclusionThe higher the Cr3C2 particle content in the composite coating, the better the coating performance, but the more rough the coating surface. The reversing of the reverse pulse current could lead to the inverse process of co-deposition. The usage of RPC could not only make the composite coating flat, but also improve the uniformity of particles dispersed in the composite coating, improving both the surface morphology and properties of the composite coating.