Zaštitno dejstvo magnetnog polja na koroziju aluminijumskih legura u rastvorima hlorovodonične kiseline

Abstract

The effect of applied magnetic fields on the corrosion of aluminium alloys AA3003 and AA8011 in hydrochloric acid solutions at room temperature has been investigated by using the gravimetric technique. The magnetic fields were generated from a locally made electromagnet with variable outputs. They were applied at right angles to the surfaces of the aluminium alloy samples when completely immersed in the test solutions. The corrosion rates of the aluminium alloys AA3003 and AA8011 in 0.5M HCl acid solutions were monitored at different applied magnetic fields. Results show that the corrosion rates of the aluminium alloy samples studied decrease with increase in the applied magnetic field. This implies that the presence of magnetic field inhibits the corrosion of the aluminium alloy AA3003 and AA8011 samples. With applied magnetic fields in the range of 254.3 - 1040.6 mG [0.0254 - 0.1041 mT], the protection efficiency of the magnetic field observed for AA3003 in 0.5M HCl acid solutions ranges from 19.3 - 94.1% while for aluminium alloy AA8011 in identical test solutions, the protection efficiency ranges from 11.5 - 78.0%. The protection mechanism is attributed partly to the phenomenon of transverse magnetoresistance and partly to effect of the magnetic fields on the mass transport pattern of constituent ions in the electrochemical system.