Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7106824 | Progress in Organic Coatings | 2015 | 9 Pages |
Abstract
This study reports the effects of different cleaning procedures on the surface characteristics of the aluminium alloy 1050 substrates and on the adhesive strength of the epoxy coating to this alloy's surface. The cleaning procedures used in this study were (1) degreasing by acetone, (2) alkaline etching by 5Â w/w% NaOH solution and (3) alkaline etching by 5Â w/w% NaOH solution followed by acid cleaning by 50Â v/v% HNO3 solution. The surface morphology, chemical composition and topography of the cleaned substrates were investigated by field-emission scanning electron microscope (FE-SEM), energy dispersive spectroscopy (EDS) and atomic force microscope (AFM), respectively. The effectiveness of the cleaning procedures was also studied by polarization test and open circuit potential (OCP) measurements. The surface free energy and work of adhesion were obtained on the cleaned samples using contact angle measuring device. Pull-off test was conducted to evaluate the adhesion strength of the epoxy coating on the aluminium substrates. Results revealed that the surface cleaning of aluminium alloy by alkaline etching followed by acid cleaning method was the most efficient procedure for removing the oxide layer from the surface of aluminium compared to other cleaning procedures. The surface roughness, surface free energy, electrochemical activity and adhesion strength of the epoxy coating to the aluminium surface were significantly increased using this surface cleaning procedure.
Related Topics
Physical Sciences and Engineering
Chemical Engineering
Process Chemistry and Technology
Authors
S. Sharifi Golru, M.M. Attar, B. Ramezanzadeh,