ABSTRACT
The surface metallization of zirconia-toughened alumina (ZTA) particles with Ni–Cu bimetallic coatings is performed by electroless plating assisted with choline chloride–ethylene glycol (ChCl-EG) ionic liquid. The possible reactions and deposition sequences of the plating process have been analyzed based on the micro-morphologies of the Ni–Cu coated ZTA (ZTA@Ni–Cu) particles obtained at different reaction stages. The roles of ChCl-EG additive, reaction temperature, and ZTA concentration on the surface morphology, coating thickness, and element content of the ZTA@Ni–Cu particles are also investigated. Results show that uniform cauliflower-characteristic Ni–Cu coatings are formed on ZTA surfaces with 35 g·L−1 ChCl-EG at 65°C. The coating thickness is about 26.9 μm, and the element contents of Cu and Ni are 38.1 at% and 61.9 at%, respectively. Besides, a schematic illustration about the fabrication of ZTA@Ni–Cu particles is proposed to elaborate the formation process of Ni–Cu coatings and the function mechanism of ChCl-EG additive.
Acknowledgments
The authors acknowledge the financial support of the National Natural Science Foundation of China (Project No. 51604136, 51571103).
Disclosure statement
No potential conflict of interest was reported by the authors.