Abstract This study investigates the combined influence of horizontal directional solidification and subsequent T6 heat treatment on the microstructural evolution and the resulting electrical and mechanical properties of an Al-6201 alloy. Unsteady-state horizontal solidification was performed using a water-cooled mold system, enabling real-time thermal mapping during solidification. The acquired thermal data were used to determine the solidification parameters, including growth rate (V L ), cooling rate (T R ), and local solidification time (t SL ). Following solidification, the alloy was subjected to a T6 heat treatment consisting of solution at 530 °C for 3 h, water quenching at room temperature, and artificial aging at 200 °C for 2.5 h. Variations in T R promoted a macrostructural transition from columnar to equiaxed grains and refinement of the Al-rich dendritic matrix. Finer secondary dendrite arm spacing (λ2) contributed to increased hardness by hindering dislocation mobility. After the T6 treatment, precipitation hardening improved mechanical performance, resulting in a 51% increase in hardness and a 65% rise in ultimate tensile strength. The processed alloy achieved a tensile strength of 320.48 MPa, an electrical resistivity of 33.6 nΩ m, and an electrical conductivity of 51.2% IACS, evidencing a superior balance between strength and conductivity.
Marques et al. (Sat,) studied this question.