The role of constituent phases on corrosion initiation of NiAl bronze in acidic media studied by SEM-EDS, AFM and SKPFM

Scanning electron microscopy (SEM), atomic force microscopy (AFM) and scanning Kelvin probe force microscopy (SKPFM) were used to examine the role of constituent phases of a NiAl bronze in corrosion initiation in HCl solution. Volta potential revealed anodic character of K phases with tens of mV higher than copper rich a phase as cathodic matrix. A correlation between SKPFM results and Work function values of constituents was obtained. SEM and AFM images revealed that the iron rich kappa phases are the most preferential sites for corrosion initiation. (C) 2013 Elsevier Ltd. All rights reserved.