Irving Ignacio López-López

Multifunctional hybrid spheres were developed via ionic gelation, using sodium alginate as an encapsulating matrix to integrate TiO₂, Fe₃O₄, activated carbon, hypochlorite-impregnated clinoptilolite zeolite, and metallic copper, followed by chitosan coating and glutaraldehyde cross-linking to enhance mechanical stability. The material combines photocatalytic, adsorbent, antimicrobial, and magnetic functions in a single system, expected to support partial treatment of contaminated water. X-ray diffraction confirmed the expected crystalline phases with no impurities. Physicochemical evaluation showed reductions in turbidity (1.8 to 0.7 NTU), total hardness (306 to 150 mg/L), iron (0.4 to 0.01 mg/L), and lead (2 = 0.8868). These results demonstrate a synergistic effect among adsorption, photocatalysis, disinfection, and magnetic recovery, positioning the hybrid spheres as a promising alternative for sustainable water treatment technologies.

High-entropy alloys (HEAs) and refractory high-entropy alloys (RHEAs) have received considerable attention as innovative reinforcements to replace traditional ceramics in lightweight matrices. However, understanding how different high-entropy systems interact under ultra-fast consolidation pathways remains an open challenge. This study compares conventional sintering (CS) and high-frequency induction hot sintering (HFIHS) in an Al-4.5Cu-1.5Mg matrix reinforced with AlCoCrFeNiTi (HEA) and WMoTaNbV (RHEA) particles at various concentrations, enabling a direct comparison of both reinforcement types under identical processing conditions. Results show that HFIHS achieves near-theoretical densification within minutes while restricting atomic mobility and precipitate coarsening through sustained pressure and short thermal exposure. Furthermore, the study observes a clear strengthening dependence on reinforcement content, with the HEA system exhibiting unexpectedly superior mechanical performance and load-bearing capacity compared to the RHEA. Finally, the correlations between ultra-fast sintering, phase evolution, and strengthening mechanisms are discussed, highlighting HFIHS as a promising route for developing high-strength lightweight composites.

This study reports the fabrication of Al 1050/WC composites (2 and 4 wt.% WC) using a novel ingot-stacked, disc-consolidated approach via indirect extrusion. The results revealed that indirect extrusion transformed the initial flat, WC-coated disc interfaces into a geometrically ordered concentric ring distribution across the composite cross-section. This architecture exhibited local variable thickness and angular discontinuities due to non-uniform material flow. X-ray diffraction confirmed interfacial stability at 485 °C and detected only the Al and WC phases. X-ray computed tomography quantified an overall porosity of 2.04 vol.%, characterized by irregularly shaped pores resulting from incomplete solid-state consolidation. Higher cross-sectional microhardness values were obtained at 47.8 ± 3.6 HV (2 wt.% WC) and 49.75 ± 5.6 HV (4 wt.% WC). Uniaxial tensile tests yielded ultimate tensile strengths of 81.05 ± 3.43 MPa (2 wt.% WC) and 89.45 ± 2.85 MPa (4 wt.% WC), which exceed the value reported for annealed Al 1050 by 62% and 79%. This flow-induced formation of a concentric reinforcement architecture through disc stacking and indirect extrusion provides a novel processing route, extending solid-state functional gradient material processing to single-step thermomechanical consolidation.

The study presents a comprehensive report on the kinetic and thermodynamic parameters of carbide crystallization in CrMnFeCoNi, CrMnFeCoNiV_0.5, and CrMnFeCoNiMo_0.5 HEAs. This study considers only carbon resulting from the decomposition of the process control agent, which diffuses and becomes trapped within the HEA structure (0.79–0.91 wt.% C). The crystallization and growth of the carbides were monitored through thermal analysis and thermo-XRD at different temperatures. The activation energy was calculated using the Kissinger and Flynn/Wall/Ozawa methods, and the crystallization kinetics were evaluated using the Avrami–Erofeev model. The results of the XRD analyses and DTA curves of the CrMnFeCoNi, CrMnFeCoNiV_0.5, and CrMnFeCoNiMo_0.5 HEAs showed the following nanocarbide crystallization sequences: M₇C₃→MC→M₃C₂, M₂₃C₆, and MC→M₆C, respectively. The transitions observed in the DTA curves were associated with M₇C₃, M₂₃C₆, and MC phases with activation energies (E_a) of 238–251, 188–203, and 326–341 kJ/mol, respectively. Furthermore, kinetic analyses indicate that the crystallization of M_xC_y-type carbides occurs via nucleation.