超声辅助换向脉冲喷射电沉积钴-碳化铬复合镀层

摘要

A Co-Cr3C2 composite coating was obtained on the surface of 45 steel by ultrasound-assisted pulse-reverse jet electrodeposition.The effects of ultrasound power and interval time on mass fraction of Cr3C2 particles,surface morphology,microhardness,surface roughness and wear resistance of Co-Cr3C2 composite coating were studied.The assistance of ultrasound greatly improves the structure and properties of Co-Cr3C2 composite coating.The composite coating obtained at an ultrasound power of 36 W with an ultrasound interval time of 8 s has the lowest surface roughness,uniform and compact surface with few pores,26.85wt％ Cr3C2 particles,which are evenly distributed in the cobalt matrix,a microhardness up to 695 HV,and a friction coefficient as low as 0.12.The composite coating presents a good thermal stability at 800 ℃.Its microhardness is apparently higher than that of hard chromium coating after heat treatment at 500 ℃.%采用超声辅助换向脉冲喷射电沉积技术在45钢表面制备了Co-Cr3C2复合镀层.研究了超声功率和超声间歇时间对Co-Cr3C2复合镀层的Cr3C2颗粒质量分数、微观形貌、显微硬度、表面粗糙度和耐磨性的影响.超声波的加载极大地改善了复合镀层的组织结构和性能.超声功率为36 W、超声间歇为8 s时,Co-Cr3C2复合镀层的表面粗糙度最低,均匀致密,鲜有孔隙,Cr3C2颗粒在镀层中的质量分数达到26.85％并均匀地分布在钴基质中,其显微硬度高达695 HV,摩擦因数仅为0.12.该复合镀层在800℃时仍有很好的热稳定性.当热处理温度高于500℃时,复合镀层的显微硬度明显高于硬铬镀层.