Analysis of Thermal and Structural Parameters and Microhardess Variations in Different Al-Cu Alloys Directionally Solidified

Abstract

The columnar-to-equiaxed transition (CET) was investigated in AI-Cu alloys (AI-Iwt%Cu, AI-4.5wt%Cu, AI-15wt%Cu and AI-33.2wt%Cu) solidified directionally from a chili face in a vertical setup. The CET occurs when the temperature gradient in the melt ahead of the columnar front reach critical values. Also, we investigate correlations between structural parameters (grain size) with Vickers microhardness measurements in the directionally soliditied sampIes. We observed that the Vickers microhardness is greater in the equiaxed zone than in the colunmar or columnar to equiaxed transition (CET) zone, additionally, is greater on the edges of the sampIes than in the centre. Also, we determined that the grain size increases from the columnar to equiaxed structure.