A cryogenic fracture technique for characterizing zinc-coated steels

The examples described in this paper show that the cryogenic fracture technique, when used in conjunction with the SEM, is capable of characterizing the structural features of zinc coatings on steels. Cleavage facets that correspond to coating grain size and fine second-phase particle distributions are revealed by the technique. Light etching of the fracture surfaces provides information about coatings growth that can be correlated with electrolytic deposition and other processing parameters. Also, in parallel with surface SEM observation, the technique has been used to characterize mechanisms of coating fracture that might influence friction and performance of coated steels during sheet-metal-forming operations