Ablación láser de recubrimientos de politetrafluoretileno (PTFE) aplicados sobre sustratos EN AW-5251

Abstract

Currently the most common used methods for removing PTFE rich coatings on metal substrates are: grinding, pyrolysis, chemical processes or a combination of these. While effective, all present serious difficulties. In this paper the use of laser ablation to remove PTFE rich coatings, which have previously been applied to sheets of aluminum magnesium alloy EN AW-5251 H34, is proposed. For this purpose the values of the yield strength, tensile strength, percent elongation, impact energy retained and hardness are analyzed. Equally, the grain size distribution at the microstructural level, the ASTM average grain size and distribution of constituent particles have been evaluated. Measurements were performed to three successive stages of application and laser coating removal. Moreover, the previous set of properties have been determined for the same substrates and stages but using pyrolysis to remove the coating. Comparison of the results shows that the removal by laser ablation does not cause any reduction in the properties of the substrates and may become an industrial alternative to traditional disposal procedures. Copyright: