Microhardness Analysis of Directionally Solidified Al-Si Alloys

EDGAR IBAÑEZ; PAULA ALONSO; ALICIA ARES

San Diego

Encuentro; THE 152nd TMS ANNUAL MEETING EXHIBITION; 2023

The Minerals, Metals and Materials Society

The columnar to equiaxed transition (CET) was studied in Al-Si alloys (Al-5wt.%Si, Al-10wt%Si and Al-12wt%Si,) which were solidified directionally upward from a chill face. The size of the equiaxed grains increase with distance from the transition, an observation that was independent of alloy composition. Microhardness values were measured for each of the macrostructure zones (columnar, CET and equiaxed). When comparing the microhardness between lamellae and interlamellae, it was observed that lamellae are significantly higher in microhardness with respect to interlamellae for each of the zones of the macrostructure. Analyzing the specific values of the microstructures (lamellae and interlamellae), it was observed that comparing the microhardness values for the macrostructure in the CET zone presents significantly different values with respect to the columnar and equiaxed zone for the lamellae microhardness values. In all uses, the results obtained in the present investigation were compared with previous results published in the literature.