电镀镍钴合金多层磨粒砂轮电解修整机理

摘要

修整是多层电镀超硬磨粒砂轮精密磨削的关键技术之一.电镀镍钴合金硬度和强度高,是理想的超硬磨料砂轮结合剂;但同时也导致砂轮修整困难.为此对镍钴合金镀层的电解修整机理进行了研究.首先,根据标准电极电位的理论分析了镍钴合金电解修整的可行性;然后,采用电化学分析仪测试了镍钴合金镀层在NaNO3溶液中的极化曲线,表明极化曲线存在钝化区;最后,进行了电解修整镍钴合金镀层CBN砂轮试验,结果表明对于2V和5V的电解修整电压,较高的电解电压有利于电镀镍钴合金超硬磨料砂轮电解修整.%Dressing is one of key technologies for the electroplated multilayer superabrasive wheel used in precision grinding.Because of the high hardness and strength of electroplated nickel-cobalt（Ni-Co） alloy,which is an ideal bonding for superabrasive wheel,the electroplated superabrasive wheel is hard to true or dress.For this purpose,the mechanisms of electrolytic dressing of the Ni-Co alloy bonding electroplated wheel were studied.Firstly,based on the standard electrode potential,the feasibility of the electrolytic dressing of Ni-Co alloy bonding was analyzed in terms of theory.Secondly,the polarization curve of the electroplated Ni-Co alloy layer in NaNO3 solutions was measured by an electrochemical analyzer.The testing results show that there is a passivating region on the curve.At last,the electrolytic dressing experiments on an electroplated CBN wheel with Ni-Co alloy bonding were conducted.The experimental results show that the higher electrolytic voltage is of advantage to the electrolytic dressing of Ni-Co alloy bonding when the electrolytic voltage of 2 V and 5 V is used.