CORROSION RESISTANCE OF AL-CU ALLOYS IN FUNCTION OF THE MICROSTRUCTURE

ALEJANDRA S. ROMAN; CLAUDIA M. MENDEZ; ALICIA E. ARES

Las Vegas, Nevada

Conferencia; INTERNATIONAL CONFERENCE ON PROCESSING ¬ MANUFACTURING OF ADVANCED MATERIALS, THERMEC 2013; 2013

THERMEC

Aluminum and its alloys are characterized by low density, high electrical and thermalconductivity, and good resistance to corrosion in certain media such as air. The mechanical strengthalloy is achieved. The objective of the present research consist on studying the type of structure(columnar, equiaxed or with columnar to equiaxed transition, CET) using parameters of thesolidification process and electrochemical parameters in Al, Cu and Al-Cu alloys with differentconcentrations. In order to obtain columnar, equiaxed and CET structures, the alloys weredirectionally solidified upwards in an experimental set up with a set of thermocouples in thesamples which permit to determine the time dependent profiles during the process. Theelectrochemical studies of the samples were realized by using an electrochemical impedancespectroscopy (EIS) technique and potentio-dynamic polarization curves immersed in 3% NaClsolution at room temperature. In general, we observed that the susceptibility to corrosion of thedifferent structures depends on the size of the secondary dendritic spacing and the proportion ofAl2Cu phase and Al-rich phase.