Development of a resistive system for the directional solidification of aluminum alloys under transient thermal conditions
Luiz Gabriel da Silva Nascimento, Mário Vinícius Machado da Silva, Joevan Ramos Nascimento, Dnilson Silva Braga, Deibson Silva da Costa
Abstract
Aluminum alloys are strategic materials for automotive and aerospace applications due to their low density, corrosion resistance, and favorable mechanical properties. Controlling solidification is essential for ensuring the final performance of cast components, and directional solidification is particularly relevant because it enables the imposition of controlled thermal gradients and the formation of columnar structures, allowing direct correlations between thermal parameters and microstructural evolution. In the resistive device developed in this study, the solidification of the Al–9%Ni alloy resulted in a predominantly columnar macrostructure, as confirmed by macrographic analysis along the ingot. Thermocouple measurements revealed thermal profiles characterized by progressively slower cooling as the distance from the metal/mold interface increased, indicating a decreasing cooling rate along the ingot. The liquidus isotherm position exhibited excellent mathematical fitting (R2 = 0.99), accurately describing the evolution of the solidification front. The isotherm velocity also showed a decreasing trend with position, with a similarly high coefficient of determination (R2 = 0.99). Likewise, the cooling rate decreased from approximately 7 °C/s at the base to below 3 °C/s in the upper regions. These findings demonstrate that the device produces an effectively unidirectional thermal gradient and allows reliable monitoring of solidification variables, highlighting its scientific and industrial potential.
Keywords
Referências
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Submetido em:
26/08/2025
Aceito em:
25/03/2026
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