平均电流密度对脉冲电镀Ni-Cr-Mo合金镀层的影响

摘要

Ni-Cr-Mo alloy coatings were prepared on the surface of Q235 steel by pulse electroplating.Effect of average current density on the composition,deposition rate,surface morphology and corrosion resistance of the coatings was investigated.Results showed that,with the increasing of average current density,the mass fraction of Ni decreased first and then increased,however the mass fraction of Cr increased first and then decreased,and the mass fraction of Mo increased.The deposition rate increased first and then decreased,and the size of particles on coating surface increased.The corrosion resistance was enhanced first and then weakened.The coating prepared at 10 A/dm2 exhibited the best corrosion resistance with the highest self-corrosion potential,the smallest self-corrosion current density and the biggest charge transfer resistance.%采用脉冲电镀法在Q235钢表面制备Ni-Cr-Mo合金镀层.研究了平均电流密度对镀层的成分、沉积速率、表面形貌和耐蚀性的影响.结果表明:随着平均电流密度的增大,镀层中镍的质量分数先减小后增大,铬的质量分数先增大后减小,钼的质量分数增大;镀层的沉积速率先增大后减小;镀层表面颗粒尺寸增大;镀层的耐蚀性先增强后减弱.当平均电流密度为10 A/dm2时,镀层具有最正的自腐蚀电位、最小的自腐蚀电流密度和最大的电荷转移电阻,耐蚀性最好.