Effect of Cu Addition on the Electrochemical Corrosion Performance of Ni₃Al in 1.0 M H₂SO₄

The effect of Cu addition on the electrochemical corrosion behavior of Ni 3 Al intermetallic alloy was investigated by potentiodynamic polarization, open-circuit potential, linear polarization resistance, and electrochemical impedance spectroscopy in 1.0 M H 2 SO 4 solution. Performance of the pure elements (Cu, Ni, and Al) was also evaluated. In general, Cu addition improved the corrosion resistance of Ni 3 Al. Electrochemical measurements show that corrosion resistance of Ni 3 Al-1Cu alloy is lower than that of other intermetallic alloys and pure elements (Ni, Cu, and Al) in 1.0 M H 2 SO 4 solution at 25°C. Surface analysis showed that the Ni 3 Al alloys are attacked mainly through the dendritic phases, and Cu addition suppresses the density of dendritic phases.