Structural Characterization, Dimensionless Numbers and Mechanical Properties of Al-Cu Alloys

ARES, A.E.; RODRIGUEZ, CARLOS MARÍA; SCHVEZOV, C. E.; MARIO ROBERTO ROSENBERGER

Procedia materials

Elsevier

Año: 2012 vol. 1 p. 72 - 79

1877-7058

The columnar - to - equiaxed transition (CET) was investigated in Al-Cu alloys (Al-1wt.%Cu, Al-4wt.%Cu, Al-15wt.%Cu and Al-33.2wt.%Cu) solidified directionally upward from a chill face. The CET occurs when the temperature gradient in the melt ahead of the columnar front reaches minimum and critical values. Thus, dimensionless parameters (W and P numbers), which allowed formulating the problem such that the final results are independent of any specific alloy system, were defined. Also, the correlations between Vickers microhardness measurements and the alloy concentration and structure (columnar, CET and equiaxed) in the directionally solidified samples were investigated. The results showed that Vickers microhardness was greater in the equiaxed zone than in the columnar or CET zones and that it increased as the copper content in the alloy increased. Finally, Vickers microhardness increased as the W number increased, regardless of the type of structure (columnar or equiaxed). The correlation between Vickers microhardness and the P number allowed observing two different behaviors depending on the type of structure (columnar or equiaxed).