Fig. 6
Comparison of coating defects under microscope. (a) B72 on steel at t = 1. No defects are visible. (b) B72/TiO2 on steel at t = 0. Addition of NPs leads to the appearance of localised pores. (c) B72/TiO2 on steel at t = 1. The appearance of pores grows abruptly. (d) Defects of OW on steel at t = 1. (e) C80 on brass at t = 1. Wax seems to restructure leaving gaps, with areas of the metal left unprotected (delimited by dashed white line). (f) C80 on steel at t = 1. Wax grains (one of these is indicated by the arrow) predominate over a coating with few pores