The properties of the final product obtained by solidification directly result from the thermal variables during solidification. This study aims to analyze the influence of thermal solidification variables on the hardness, microstructure, and phases of the CuAl₆Si₂ alloy. The material was solidified using unidirectional solidification equipment under non-stationary heat flow conditions, where heat extraction is conducted through a water-cooled graphite base. The thermal solidification variables were extracted using a data acquisition system, and temperature was monitored at six different positions, with cooling rates ranging from 217 to 3 °C/min from the nearest to the farthest position from the heat extraction point. An optical microscope, scanning electron microscope (SEM), and X-ray diffraction (XRD) were used to verify the fusion structure and determine the volumetric fraction of the formed phases. The XRD results showed the presence of β phases, α phases, and possible Fe₃Si₂ and Fe₅Si₃ intermetallics with different morphologies and volumetric fractions. Positions with lower cooling rates showed an increased volume fraction of the α phase and possible intermetallics compared to positions with faster cooling. High cooling rates increased the Brinell hardness of the alloy due to the refined and equiaxed β metastable phase, varying from 143 HB to 126 HB for the highest and lowest rates, respectively.

The mechanical properties of a final product are directly influenced by the solidification process, chemical composition heterogeneity, and the thermal variables during solidification. This study aims to analyze the influence of solidification thermal variables on the microstructure, hardness, and phase distribution of the CuMn11Al8Fe3Ni3. The alloy was directionally and upward solidified from a temperature of 1250 °C. Heat extraction occurred through a water-cooled AISI 1020 steel interface. The thermal variables were recorded using a data acquisition system, with temperature monitored at seven different positions, where cooling rates varied from 13.03 °C/s at the closest position to 0.23 °C/s at the farthest. The Brinell hardness decreased from 199 HB at the highest cooling rate position to 184 HB at the slowest cooling rate position. This indicates that higher cooling rates increase the hardness of the alloy, which can be attributed to the stabilization of the metastable β phase with refined and equiaxial grains due to iron addition. Vickers microhardness was observed in regions subjected to slower cooling (244 HV) compared to faster cooling regions (222 HV). Therefore, the correlation between solidification thermal variables and alloy properties provides valuable insights into the relationship between microstructure and the properties of the CuMn11Al8Fe3Ni3 alloy.

The increasing use of multi-material automotive structures has intensified the demand for reliable joining technologies capable of integrating lightweight aluminum alloys with ultra-high-strength steels. This study investigated the formation mechanisms, geometrical characteristics, mechanical performance, and interfacial behavior of dissimilar AA5182 aluminum alloy and 22MnB5 press-hardened steel joints produced by clinching. Cross-sectional metallography, mechanical testing, scanning electron microscopy (SEM), and energy-dispersive spectroscopy (EDS) were employed for characterization. The analyzed joint cross-section exhibited well-developed mechanical interlocking, with left and right interlock lengths of 0.175 and 0.191 mm, respectively. Severe localized deformation during clinching produced thickness reductions of approximately 75% in AA5182 and 67% in 22MnB5. Mechanical testing showed a higher peak load under lap-shear loading (1210 ± 130 N) than under cross-tension loading (900 ± 40 N). SEM observations revealed extensive interfacial contact without major discontinuities, while EDS indicated localized redistribution of Al, Fe, and Si associated with deformation of the Al–Si-coated interface. No clear evidence of diffusion-controlled metallurgical bonding was identified. The results indicate that joint integrity was governed primarily by mechanical interlocking, with interfacial friction considered a possible secondary contribution to load transfer, demonstrating the technical feasibility of clinching for AA5182–22MnB5 multi-material structures.