(中南大學(xué) 材料科學(xué)與工程學(xué)院，長(zhǎng)沙 410083)
摘 要: 采用循環(huán)伏安(CV)和恒電位階躍(CA)等電化學(xué)技術(shù)，研究金剛石粉體對(duì)Ni電結(jié)晶形核/生長(zhǎng)的影響，并通過(guò)掃描電鏡觀察復(fù)合鍍層的表面形貌。結(jié)果表明：在Ni-金剛石復(fù)合鍍液中，金剛石粉體吸附在陰極表面，對(duì)陰極產(chǎn)生屏蔽作用，Ni2+的有效放電面積減小，阻礙電荷轉(zhuǎn)移，使復(fù)合鍍液在循環(huán)伏安曲線(xiàn)中的還原電流降低；金剛石粉體縮短了Ni電結(jié)晶的形核馳豫時(shí)間(tmax)，形核過(guò)電位正移，促進(jìn)Ni電結(jié)晶形核；電鍍時(shí)間越長(zhǎng)，金剛石復(fù)合量越小，鍍層表面越粗糙；Ni-金剛石復(fù)合鍍液和純Ni鍍液的Ni電結(jié)晶形核可能為多晶沉積。
關(guān)鍵字: 金剛石；復(fù)合電鍍；Ni；電結(jié)晶；形核；生長(zhǎng)；多晶沉積
（School of Materials Science and Engineering, Central South University, Changsha 410083, China）
Abstract:The effect of diamond powder on the nickel electrocrystallization nucleation/growth behavior was investigated by electrochemical techniques, such as cyclic voltammetry(CV) method and chronoamperometry method (CA), and the surface morphologies of composite coatings were observed by SEM. The results show that, in Ni-diamond electroplating solutions, diamond powder absorbed on the cathode surface decreases the effective area of Ni ion discharge and hinders the process of charge transfer because of the shielded cathode surface, which corresponds to much lower reduction current of CV curve; diamond powder shortens the nucleation relaxation time tmax of Ni electrocrystallization, the nucleation potential turns to positive direction, and Ni electrocrystallization is stimulated; the diamond powder content in Ni-diamond composite coatings decreases with the increase of electroplating time, which makes the surface of coatings coarsen; both Ni-diamond electroplating solution and pure Ni electroplating solution may follow the polycrystalline deposition mechanism.
Key words: diamond; composite electroplating; Ni; electrocrystallization; nucleation; growth; polycrystalline deposition
