RELATIONSHIP BETWEEN STRUCTURE AND PROPERTIES OF AL-CU ALLOYS

ALICIA E. ARES; LILIANA M. GASSA; CARLOS E. SCHVEZOV; SERGIO F. GUEIJMAN

San Diego, CA, USA

Simposio; The Annual Meeting of the TMS - Shape Casting Symposium; 2011

TMS

The objective of the present research consists on studying the type of structure (columnar,equiaxed or with columnar to equiaxed transition, CET) using parameters of the solidificationprocess and electrochemical parameters in Al-Cu alloys with different concentrations.In order to obtain columnar, equiaxed and CET structures, the alloys were directionally solidifiedupwards in an experimental set up with a set of thermocouples in the samples which permit todetermine the time dependent profiles of temperature during the process. The electrochemicalstudies of the samples were realized by using an electrochemical impedance spectroscopy (EIS)technique and potentio-dynamic polarization curves immersed in 3% NaCl solution at roomtemperature. In general, we observed that the susceptibility to corrosion of the differentstructures depends on the size of the secondary dendritic spacing and proportion of Al2Cu phaseand Al-rich phase.