(中南大學(xué) 材料科學(xué)與工程學(xué)院，長沙 410083)
摘 要: 采用電鍍法制備鍍Ti金剛石-Ni-Co復(fù)合鍍層，研究鍍液中Co2+含量對鍍層形貌和性能的影響，并通過電化學(xué)阻抗譜研究Ni-Co復(fù)合電沉積過程。結(jié)果表明：當(dāng)鍍液中未添加Co2+時，所制備的鍍Ti金剛石-Ni復(fù)合鍍層內(nèi)凹痕較多；鍍液中添加Co2+后，鍍Ti金剛石-Ni-Co復(fù)合鍍層內(nèi)凹痕消失，晶粒均勻。隨著鍍液中Co2+含量的增加，所制備的鍍Ti金剛石復(fù)合鍍層的顯微硬度先增加后減少。當(dāng)鍍液中Co2+含量為6%(摩爾分?jǐn)?shù))時，在-0.85 V電位下Ni-Co共結(jié)晶電化學(xué)阻抗譜的電荷轉(zhuǎn)移電阻最大，制備的鍍Ti金剛石-Ni-Co鍍層內(nèi)金剛石含量最高。此外，當(dāng)鍍液中Co2+含量增加至8%時，鍍Ti金剛石-Ni-Co復(fù)合鍍層內(nèi)金剛石粉體的沉積量最少。
關(guān)鍵字: Ni-Co合金；金剛石；鍍鈦；復(fù)合電沉積；交流阻抗
（School of Materials Science and Engineering, Central South University, Changsha 410083, China）
Abstract:The Ti-coated-diamond-Ni-Co coating was prepared by electroplating process. Moreover, the effect of Co2+ content variation on the morphology and property of the Ti-coated diamond-Ni-Co coating was investigated. Meanwhile, the composite electrodeposition process was studied by electrochemical impedance spectroscopy (EIS). The results show that there are many dents on the Ti-coated diamond-Ni coating when Co2+ is not added in the plating bath. However, the dents disappear and the grain size becomes more uniform when Co2+ is added into the plating bath. Moreover, with the increase of Co2+ content in the plating bath, the microhardness of the composite coatings rises firstly and then declines. As Co2+ content in the plating bath is 6% (mole fraction), the charge transfer resistance of the Ni-Co codeposition evaluated from the EIS at -0.85 V reaches the maximum value, and the content of diamond in the composite coating is the highest. In addition, as Co2+ content in the plating bath increases to 8%, the content of diamond in the composite coatings is the least.
Key words: Ni-Co alloy; diamond; Ti plating; composite electrodeposition; alternating current impedance
