Fig. 9 displays the growth of two of the main corrosion products that develop or form on the surface of Cu40Zn with time, hydrozincite (Fig. 9a) and Cu2O (Fig. 9b). It should be remembered that both phases were present already from start of the exposure. The data is presented in absorbance units and allows comparisons to be made of the amounts of each species between the two Cu40Zn surfaces investigated, DP and HZ7. The tendency is very clear that the formation rates of both hydrozincite and cuprite are quite suppressed for Cu40Zn with preformed hydrozincite (HZ7) compared to the diamond polished surface (DP). In summary, without being able to consider the formation of simonkolleite, it can be concluded that an increased surface coverage of hydrozincite reduces the initial spreading ability of the NaCl-containing droplets and thereby lowers the overall formation rate of hydrozincite and cuprite.
