Characterization of interfacial strength of dissimilar metallic joints using a scanning Kelvin probe

It is very important to understand the interfacial behavior for effective evaluation of welding quality. This letter reports a simple nondestructive characterization method of the interfacial strength of dissimilar metallic joints. Using a scanning Kelvin probe, the electron work function of Cu–steel joints was measured and a strong correlation between the electron work function and the interfacial tensile strength was found.