RESEARCH ON ANTICORROSION CHARACTERISTICS OF ALZN PSEUDO-ALLOY OBTAINED BY METAL-ARC PROCESS

摘要

The paper analyzes the corrosion resistance in corrosive environments of some metallization layers obtained by metal-arc process, using two different wires made of Al and Zn. It has been started from the assumption that the deposit obtained is different from an alloy of the two chemicals and that is in a state of theoretical disequilibrium, due to physico-chemical and mechanical differences between the two materials, for which he was called "pseudo-alloy ". The paper is trying to bring closer to steady state by applying to the pseudo-alloy of a heat treatment performed after metallization. To this end was made a heat treatment using a flame to 300℃ followed by cooling in air and maintaining in the oven at 350℃ for 30 minutes with controlled cooling, avoiding extra heating effect which can start the eutectic reaction (382℃). The quality criteria considered for the analysis of material behaviour have targeted microstructural changes and corrosion resistance. Analyzing microstructural features and those of corrosion behaviour of deposits made by pseudo-alloys AlZn, has been performed some measures to improve the properties, being shown the superiority of these deposits in relation to the singular behaviour of zinc or aluminium, with direct effects on the reliability of practical applications.