This study investigates galvanic corrosion in heterogeneous metal materials utilized in cold plate assemblies for single-phase liquid cooling systems. The galvanic corrosion behavior (Tafel plot) of pure copper, stainless steel 304, stainless steel 316, and nickel-based brazing fillers (BNi2 and BNi6) immersed in PG25 working fluid was measured on days 0, 7, and 60. Furthermore, accelerated aeration experiments were conducted on PG25 to assess its chemical stability, and its electrochemical properties were subsequently analyzed after 30 days of aeration using electrochemical methods.