Corrosion mechanism of HVOF silicate glass coating in 5% NaCl solution

ZHAN Jun¹, CHEN Gui-ming¹, LIU Xiao-fang¹, ZHA Bai-lin¹, ZHANG Qian¹, LIU Xin-nian²

1.Dept. of Military Equipment Management Engineering,The Second Artillery Engineering College,Xi¡¯an 710025,China;2.Shanxi University of Science and Technology,Xianyang 712081,China



Abstract:

On the basis of good anticorrosion capability of silicate glass,silicate glass coating was sprayed by high velocity oxygen fuel (HVOF) and the corrosion mechanism in 5% NaCl solution was studied. Scanning electron microscope (SEM) ,energy dispersive X-ray analysis (EDX) ,X-ray diffraction (XRD) and potentiometer were used to study the coating composition and corrosion process. The result shows that silicate glass coating is entirely noncrystallizable. Silicate glass coating has very low incidence of hole with compact structure. Electric double-layer can form at coating/solution interface and corrosive solution performs as a lead connecting the coating surface and substrate after permeating through glass coating. The corrosion mechanism of silicate glass coating is similar to that of glass and the entire corrosion process can be divided into some states. The whole corrosion process happens in glass coating without substrate basically. The fluctuation of the self-corrosion potential about glass coating in corrosion solution can help to research the corrosion process.

Key words:  silicate glass coating  self-corrosion potential  alkali metals

DOI£º10.11916/j.issn.1005-9113.2010.02.022

Clc Number:TG174.44

Fund: