| Abstract |
The effect of biaxial strain on the electrochemical behaviour of a thin weldable primer containing zinc-aluminium particles applied to galvanized steel was studied by assessing both the integral behavior of the system and the micro-currents on the heterogeneous surface. The ionic currents near the surface were measured by the SVET and revealed to be sensitive to the shape and lifetime of micro-active areas of the coating. The EIS data on intact coatings revealed that immersion time caused a drop of the low frequency resistance while the capacitive slope remained constant; on elongated samples, a similar trend in low frequency was observed along with an increase of the capacitance. A model is proposed, based upon an electrical equivalent electric circuit that includes distinct elements mimicking the electrochemical behaviour of the exposed and embedded metal particles and for the polymer phase. (C) 2014 Elsevier Ltd. All rights reserved. |
