Effect of Environmental Solution and Silicone Rubber on Blackening of Copper Strips for Cables

The influence of environmental solution and silicone rubber on the blackening of copper strip was analyzed by the control variable method. The results show that black phenomenon appeared on the copper strip with silicone rubber, while the black phenomenon was most serious in NaCl solution. The results of SEM and EDS show that there were a lot of pitting pits on the black spots on the surface of the copper strip. Si, S, Cl and other elements were mostly present in the pits. The line scan results show that the oxygen content of the black parts with different substrate contrast was relatively high. The FTIR results showed that the silicone rubber on the black spot copper strip was hydrolyzed. The liquid medium was not the cause of the blackening of copper strip. The pitting effect of Cl^- on copper strip matrix and the oxygen enrichment of silicone rubber were the root causes of blackening of the copper strip.