Electrochemical and morphological study on green nano-ceramic reinforce d convers ion coatin g

For improving corrosion protec tion and a dhesion to the next layer (organic paints, finishes), p retreatments are used o n metal surfaces. One of these pretreatments is the application of chemical c onversion coatings for example ph osphating process. However, this process has se veral limitations: e utrophicatio n, requires frequent desludging, requires additional sealin g step to red uce porosity and requires expensive energy input. Consequently, research on new surface pretreatments to re place p hosphating has been performed. In the last decade, one promising new pretreatment was the a pplication of zirconium oxide (Zr O۲) on the metal surfac es by immersion in a hexafluorozirconic a cid solution . Electroch emical Impedance Spectroscopy (E IS) as technique provid es qualitative and q uantitative data and plays an important role i n corrosion phenomen on studies. The nanoceramic reinforced H۲ZrF۶ conve rsion proce ss is a novel study, but the study does not addre ss the correlation b etween practical immersion param eters and the microstr ucture and anticorrosiv e performance of c onversion coatings.

کلیدواژه ها:

Nanoceramic based conversion coating ، Polariz ation ، AFM ، EIS ، FE-SE M