稀土铈对Ni-GO镀层的组织形貌和性能的影响研究

Effect of Rare Earth Cerium on Microstructure and Properties of Ni-GO Coatings

摘要:

采用电沉积方法在Q235钢上制备Ni-Go复合镀层,研究添加稀土铈对复合镀层形貌、性能的影响。结果表明,当铈浓度为0.8 g.L_-1^时,得到的复合镀层沉积速率增加到7.142 g.dm_-2^.h_^-1,^,硬度达到608.8 HV,磨损量最小,摩擦系数最低为0.387,自腐蚀电位E_corr(-0.3993 V)更正,同时腐蚀电流I_corr(3.258.10_-6 ^A.cm_-2⁾最小,腐蚀速率最低,复合镀层的耐腐蚀性能最优。研究发现,加入稀土铈后,Ni-1.0GO复合镀层的类似珊瑚状的微大尺寸的凸聚体变成了尺寸较小的珊瑚珠状的小凸聚体,镀层组织得到明显细化。在铈浓度为0.8 g.L_-1^时,Ni-1.0GO-0.8RE复合镀层的组织致密性最好,各种性能达到最佳,主要在于稀土铈提高镀液中微粒的分散能力和阴极极化率的效果,提高氢离子在阴极的析出电位,从而抑制析氢反应的发生,使得复合镀层的性能得到进一步提高。

Abstract:

Ni-Go composite coating was prepared on Q235 steel by electrodeposition. The effect of rare earth cerium on the morphology and properties of the composite coating was studied. The results show that when the cerium concentration is 0.8 g . L-1, the deposition rate of the composite coating increases to 7.142 g . dm-2 . h-1, the hardness reaches 608.8 HV, the wear amount is the smallest, the friction coefficient is the lowest, the self-corrosion potential Ecorr ( -0.3993 V ) is corrected, the corrosion current Icorr ( 3.258 . 10-6 A . cm-2 ) is the smallest, the corrosion rate is the lowest, and the corrosion resistance of the composite coating is the best. It was found that after the addition of rare earth cerium, the coral-like micro-sized convex polymer of the Ni-1.0GO composite coating became a small coral-like convex polymer with a smaller size, and the coating structure was significantly refined. When the cerium concentration is 0.8 g . L-1, the Ni-1.0GO-0.8RE composite coating has the best microstructure and the best performance. The main reason is that the rare earth cerium improves the dispersion ability of the particles in the plating solution and the cathodic polarization rate. The effect of increasing the precipitation potential of hydrogen ions at the cathode inhibits the occurrence of hydrogen evolution reaction, which further improves the performance of the composite coating.