Commercially pure aluminum (Al) was refined through the addition of the Al-5Ti-0.25C master alloy, resulting in the formation of Al₃Ti and TiC phases, which serve as refining agents. Open-cell metallic foams were successfully produced using the replication casting technique, with pore sizes ranging from 1.00 to 3.35 mm. For the infiltration process, refined aluminum was used, while unrefined aluminum served as a baseline reference. The resultant foams underwent multiple annealing cycles at 480 °C, with the most refined and homogeneous microstructure observed after 504 h. Comprehensive microstructural characterization was conducted utilizing scanning electron microscopy and optical microscopy. Additionally, uniaxial compression tests were performed to generate stress–strain profiles for the foams, facilitating an assessment of their energy absorption capacity. The findings indicated an enhancement in energy absorption capacity by a factor of 2.4 to 3, which can be attributed to the incorporation of Al-5Ti-0.25C and the subsequent annealing process.

This study presents an experimental characterization and numerical assessment of Cu–Al–Be (CAB) shape memory alloys (SMAs) for potential applications in U-shaped flexural plate (UFP) seismic dampers. Six alloy compositions were evaluated through monotonic tensile tests, ASTM F2516 superelastic protocols, and increasing-amplitude cyclic loading to identify the material exhibiting stable superelastic behavior at room temperature. Among the tested materials, alloy CAB4.76-A showed the most favorable response, with high transformation stress, stable pseudoelastic behavior, and strain recovery exceeding 95% for strains up to 2.5%. A phenomenological finite element model based on the Auricchio constitutive formulation was calibrated using experimental data within the validated strain range (ε ≤ 0.025), showing good agreement in stiffness and stress prediction. The calibrated model was subsequently applied to simulate the response of a UFP device under orthogonal cyclic loading. The results indicate a strong dependence on loading orientation due to coupled bending–torsion effects, with the 90° direction exhibiting significantly higher strength and energy dissipation capacity. Comparison with analytical formulations originally developed for steel UFPs showed that these expressions provide approximate estimates when applied to SMA-based devices. The results suggest that Cu–Al–Be alloys are a promising alternative for UFP applications, while highlighting the importance of loading orientation and the need for future experimental validation at a device scale.

The Cu–26.84Zn–5.37Al (Wt%) alloy was investigated to determine the effect of rolling temperature on microstructural evolution, dislocation density, and shape memory properties. Following fabrication and homogenization treatments (900 °C + β-phase precipitation at 500 °C), samples were plastically deformed by rolling (30% reduction) at room temperature (25 °C) and cryogenic temperature (−196 °C), followed by recrystallization at 850 °C. Complementary characterization techniques optical microscopy, XRD, DSC, Warren–Averbach analysis, nanoindentation, EIS, and potentiodynamic polarization are consistent with a higher density of lattice defects under cryogenic deformation, as indirectly indicated by XRD peak broadening, mechanical hardening, and surface electrochemical reactivity. Warren–Averbach analysis revealed a 51% reduction in crystallite size (453.4 Å → 223.7 Å). Nanoindentation confirmed superior strain hardening, constituting the principal evidence for this trend; complementary, exploratory electrochemical studies further indicated increased surface reactivity in the deformed samples, consistent with though not independently establishing dislocations acting as preferential anodic sites. Rolling followed by recrystallization, at either room or cryogenic temperature, produced a substantial grain size reduction relative to the coarse-grained homogenized condition (≈ 3816 μm) a general outcome of the deformation recrystallization route rather than a feature unique to cryogenic processing. The distinctive contribution of cryogenic deformation is evidenced by direct comparison with room-temperature processing: recrystallized grain size decreased from 64 (room temperature) to 53 μm (cryogenic), a further ≈17% refinement attributable specifically to the suppression of dynamic recovery at low temperature. The reversible martensitic transformation, a necessary precursor for the shape memory effect, was preserved after processing, as confirmed by DSC, and thermal hysteresis decreased by 42%. These results demonstrate that cryogenic deformation followed by controlled recrystallization is an effective thermomechanical route for simultaneously optimizing grain size and functional properties in Cu–Zn–Al shape memory alloys.