The Effect of Surfactant Content over Cu-Ni Coatings Electroplated by the sc-CO2 Technique

作者：Chuang Ho Chiao^*; Sanchez Jorge; Cheng Hsiang Yun

来源：Materials, 2017, 10(4): 428.

DOI：10.3390/ma10040428

• supercritical CO2
• electroplating
• 1,4-butynediol
• Cu-Ni coating
• internal stress
• electrochemical resistance

Co-plating of Cu-Ni coatings by supercritical CO2 (sc-CO2) and conventional electroplating processes was studied in this work. 1,4-butynediol was chosen as the surfactant and the effects of adjusting the surfactant content were described. Although the sc-CO2 process displayed lower current efficiency, it effectively removed excess hydrogen that causes defects on the coating surface, refined grain size, reduced surface roughness, and increased electrochemical resistance. Surface roughness of coatings fabricated by the sc-CO2 process was reduced by an average of 10%, and a maximum of 55%, compared to conventional process at different fabrication parameters. Cu-Ni coatings produced by the sc-CO2 process displayed increased corrosion potential of similar to 0.05 V over Cu-Ni coatings produced by the conventional process, and 0.175 V over pure Cu coatings produced by the conventional process. For coatings similar to 10 mu m thick, internal stress developed from the sc-CO2 process were similar to 20 MPa lower than conventional process. Finally, the preferred crystal orientation of the fabricated coatings remained in the (111) direction regardless of the process used or surfactant content.

• 出版日期2017-4