The disparity of corrosion resistance between Ni/Au and Ni–P/Au electrical contacts in mixed flowing and salt spray tests

Electroless deposition of Ni–P/Au coating on Cu substrate with improved corrosion resistance from Au(iii)–DMH based cyanide-free plating bath using hypophosphite as a reducing agent

“…With the corrosion of Cl À , galvanic corrosion started where Au acted as the cathode and Ni as the anode. 50,63 Then Cl À continued to penetrate into the Cu substrate through the wide boundary of the Ni-P layer (Fig. 2(a)), and Ni was accelerated to be corroded through galvanic coupling with Cu.…”

“…Meanwhile, Cu used the defects of the Ni–P layer and Au layer to diffuse to the Au-top surface, and it was eventually oxidized there under the acceleration of a galvanic coupling with Au. 2 Murugan's research work 63 showed that the brown corrosion product was consisted of a thick base of Cu 2 O covered by a film of CuO (major) and Cu 2 (OH) 3 Cl (minor) with XPS analysis. It can be seen that the pores and gaps of the coating are closely related to corrosion resistance.…”