Effect of Co Concentration on Composition and Electromagnetic Shielding Properties of Ni-Co-P
Electroless Ni–Co–P alloys on PVC with sodium hypophosphite as a reducing agent in an alkaline bath was investigated. Silane coupling agent (KH560) was used during the pretreatment. The morphology, chemical composition, of the electroless plating film was characterized by scanning electron microscope (SEM) and energy dispersive spectroscopy (EDS). The effect of Co concentration on its composition and electromagnetic shielding properties were examined. The results show that the plating rate decreased totally with increasing Co concentration. The structure of the as-plated Ni–Co–P alloys at all conditions is amorphous. When the concentration of cobalt sulfate concentration is 8g•L-1, electroless Ni–Co–P alloys exhibited better electromagnetic shielding properties, shielding effectiveness of which was 52 dB at 300 MHz. The Ni–Co–P deposits, therefore, are promising for applications in electromagnetic interference for plastics substrate.
Shaobo Zhong and Zhigang Liu
M. Q. Wang et al., "Effect of Co Concentration on Composition and Electromagnetic Shielding Properties of Ni-Co-P", Applied Mechanics and Materials, Vol. 214, pp. 436-439, 2012