The Correlation between Electrochemical Corrosion Resistance and Mechanical Strength of As-Cast Al-Cu and Al-Si Alloys

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)The aim of the present work is to investigate the influence of solidification thermal parameters on the microstructural array of Al 5 wt.% Cu and Al 9 wt.% Si alloys castings with a view to developing correlations between the as-cast dendritic microstructure, the electrochemical corrosion resistance and the tensile mechanical strength. Considering the as-cast Al 5 wt.% Cu alloy, it was found that smaller secondary dendrite arm spacings (lambda(2)) increase both the ultimate tensile strength (UTS) and the corrosion resistance. For the Al 9 wt.% Si alloy, it is shown that the UTS also increase with the decrease in lambda(2), however, the corrosion resistance decreases. A combined plot of corrosion resistance and UTS as a function of lambda(2) is proposed with a view to determining an optimum range of secondary dendrite arm spacings which provides good balance between both properties.61262756289Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)FAEPEX UNICAMPFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP