Fabrication of Co-Ni-P film with excellent wear and corrosion resistance by electroplating with supercritical CO2 emulsion
(1. School of Mechanical and Automotive Engineering, South China University of Technology, Guangzhou 510640, China;
2. School of Materials and Energy, Guangdong University of Technology, Guangzhou 510006, China)
2. School of Materials and Energy, Guangdong University of Technology, Guangzhou 510006, China)
Abstract: To avoid the defects caused by the hydrogen evolution and improve the corrosion and wear properties of the electroplated films in the traditional aqueous bath electrodeposition, a supercritical carbon dioxide (Sc-CO2) emulsion was proposed to electrodeposite ternary nanocrystalline Co-Ni-P alloy films. Microstructure, corrosive and tribological properties of the Co-Ni-P films were investigated and compared with the ones electroplated by conventional method. The results show that the Co-Ni-P films produced with Sc-CO2 assisted electrodeposition exhibit a more compact microstructure. The preferred orientation plane of hcp (110) for the Co-Ni-P films produced in conventional aqueous bath is changed to be hcp (100) for the one prepared in emulsified Sc-CO2 bath. The microhardness, corrosion resistance and tribological properties of the Co-Ni-P films are substantially improved with the assistance of Sc-CO2 in the electrodeposition bath.
Key words: Co-Ni-P film; electrodeposition; supercritical carbon dioxide; wear; corrosion