Roberto Ademar Rodríguez-Díaz

While aluminum (Al) continues to be a cornerstone for microelectronic interconnect technologies, its chronic tendency toward hillock growth and thermal instability necessitates a transition toward high-performance nanostructured material architectures. This research tackles these reliability bottlenecks by achieving a molecular-level integration of graphene nanoplatelets (GNPs) within Al matrices, a strategy designed to fortify structural resilience. Adopting a green chemistry approach, we synthesized Al-GNP (0.25 vol.%) composite thin films through Pulsed Laser Deposition (PLD) using precursors derived from recycled aluminum. A major obstacle—the formation of the deleterious Al₄C₃ intermetallic phase—was effectively suppressed by ensuring a homogeneous supramolecular dispersion via a specialized dual protocol (ultrasonication and magnetic stirring) during the powder metallurgy stage. Comprehensive physicochemical characterization, utilizing HR-TEM and XRD, verified the structural integrity of the multilayer GNPs (d-spacing = 4.6 Å). Furthermore, surface metrology analysis uncovered a radical shift in growth kinetics: whereas pure Al grew via a “spiky” Volmer-Weber mechanism (Sku = 31.17), the carbon-based inclusion stabilized the film evolution, tempering the kurtosis to Sku = 7.74. Analytical cross-sectional EDS confirmed both stoichiometric fidelity and the achievement of void-free Si/Pt/Al-GNP interfaces. These outcomes prove that a precise nanoscale tailoring of surface morphology via carbonaceous reinforcements significantly bolsters microstructural stamina. Consequently, these PLD-deposited composites emerge as sustainable, cutting-edge candidates for the next generation of microelectronic packaging and interfacial chemistry applications.

This study investigates the effect of copper (Cu) and silver (Ag) additions on the electrochemical behavior of the Fe40Al intermetallic alloy in artificial saliva, aiming to evaluate its potential for biomedical applications such as dental implants. Alloys with varying concentrations of Ag (0.5, 1.0, and 3.0 wt%) and Cu (1.0, 3.0, and 5.0 wt%) were synthesized and exposed to a biomimetic electrolyte simulating oral conditions. Electrochemical techniques, including open circuit potential (OCP), linear polarization resistance (LPR), potentiodynamic polarization, and electrochemical impedance spectroscopy (EIS), were employed to assess corrosion performance. Results show that unmodified Fe40Al exhibits good corrosion resistance, attributed to the formation of a stable passive oxide layer. The addition of Cu, particularly at 3.0 wt%, significantly improved corrosion resistance, yielding lower corrosion current densities and higher polarization resistance and charge transfer resistance values, surpassing even 316L stainless steel in some metrics. Conversely, Ag additions led to a degradation of corrosion resistance, especially at 3.0 wt%, due to microstructural changes and the formation of metallic Ag precipitates, AgSCN, and galvanic cells, which promoted localized corrosion. EIS results revealed that Cu- and Ag-modified alloys developed less homogeneous and less protective passive layers over time, as indicated by increased double-layer capacitance (C_dl) and reduced constant phase element exponent (n_dl) values. Overall, the Fe40Al alloy shows intrinsic corrosion resistance in simulated physiological environments, and Cu additions can enhance this performance under controlled conditions. However, Ag additions negatively affect the protective behavior of the passive layer. These findings offer critical insight into the design of Fe-Al-based biomaterials for dental or biomedical applications where corrosion resistance and electrochemical stability are paramount.

Dilute alloys of Ni–Si binary system have been used as base material to study microstructural changes caused by irradiation in complex alloys. However, non-dilute Ni–Si alloys, which are themselves also important for high-temperature applications, have been little studied under irradiation. In this paper, the behavior of a hypereutectic alloy, Ni22at.%Si, under severe irradiation conditions is evaluated, to determine changes induced on the surface and elucidate the possible mechanisms that promote them. As a result of irradiating this alloy with Ni ions of 3.66 MeV at 650°C and an incidence perpendicular to the surface, the presence of nanohills is detected, as well as groove patterns and craters, which formation is attributed to different sputtering mechanisms. To characterize these changes, optical, scanning electron and atomic force microscopies were used. Comparing the experimental findings with some of the most important physical models of sputtering, it was concluded that such changes to the surface microstructure strongly depend on the amount of energy deposited during irradiation and on how it is distributed in the microstructural features developed in the alloy during its manufacture. Moreover, when the radiation dose was changed to evaluate the sputtering yield as a dose function, it was detected as geometric sputtering mechanism.

The inefficient use of fuels for the burning of bricks generates importan emissions of pollutants into the atmosphere, among them carbon dioxide CO2, nitrous dioxide NO2 and Greenhouse Gases (GHG), so it is very important to quantify these emissions and establish with it a baseline of carbon dioxide emissions equivalent (CO2eq). The goal of this project is the implementation of brick kilns in the municipality of Tlajomulco of Zúñiga with the aim to reduce the ecological footprint, based on the existing ecological furnaces called MK2, having as oven innovation the placement of a second wall, which will manage to contain the generated heat, thus achieving a closed system isolated in both ovens connected to each other, to take advantage of it an optimal pre-drying of the bricks. This reseach is based on not having heat losses due to it is hermeticity, since the ecological furnaces has a double sealing wall reducing the burning time beetween 7 and 12 days.

In this study, we investigated the recrystallisation kinetics of Ti-stabilised interstitial-free (IF) steel manufactured by the Mexican steel industry through the route of electric arc furnace with vacuum degassing, secondary refining, and subsequent continuous casting. The IF steel was hot-rolled at 950°C and then cold-rolled until deformation of 94% was attained, followed by recrystallisation at different times at a constant temperature of 780°C. In addition, the mechanical properties of the IF steel were assessed as a function of recrystallisation time. The results obtained from the mechanical property tests were presented in the form of plots of microhardness, yield strength, ultimate tensile stress, and deformation percent as functions of the recrystallised fraction with an indirect dependence on recrystallisation time. A graphical model of the recrystallisation behaviour showed the evolution of the microstructure, including phase transformations, hardness, and the mechanical properties determined from the tensile tests. In view of subsequent recovery and recrystallisation, stored energy analysis derived from the strain induced by deformation was presented. Furthermore, we determined the precipitates formed in the different processing stages of IF steel.

Structural evolution of Sol-Gel glasses in powder form and coatings with incorporation of Ag particles at the starting solution showed an evolution from SiO2 amorphous matrix to the cristobalite phase with the annealing treatment at around 800 ºC for one hour. This structural evolution was obtained at lower Ag concentration up 0.7 %vol. Two series of samples were studied, A) series using HNO3 and B) series using HCl as catalytic agent; in both series grenetine was used as a dispersing agent to avoid the precipitation of Ag particles. We found the incorporation of silver in the xerogeles matrix promotes the devitrification process at relatively low temperatures with the presence of partial crystallization in form of cistobalite. This structure was produced by controlling the catalytic agent quoted in the preparation process. The EPR and UV-Vis absorption spectra show the presence of Fe3+ ions as a contaminant in the source of the Ag particles, due to the process to obtain these particles. By means the IR spectra a high (OH-) concentration at higher temperatures was observed in this system, until 600 ºC at difference of the sol-gel glasses made with incorporation of Ag particles by nitrates. The color evolution of the coating samples with the annealing temperature varies from a light brown at 100 ºC to yellow at 500 ºC. La evolución estructural de vidrios de Sol-Gel en forma de polvos y recubrimientos preparados con la incorporación de partículas de Ag a partir de la solución precursora muestra la evolución de la matriz amorfa de SiO2 a la fase cristobalita utilizando tratamientos térmicos alrededor de 800 °C por un tiempo de una hora. Dicha evolución estructural fue obtenida en concentraciones bajas a partir de 0.7% de Ag. Dos series de muestras fueron estudiadas, la serie A) usando HNO3 y la serie B) usando HCl como agente catalítico; en ambas series se uso grenetina como agente dispersante para evitar la precipitación de las partículas de Ag. Nosotros encontramos que la incorporación de plata en la matriz de los xerogeles promueve el proceso de desvitrificación a temperaturas relativamente bajas con la presencia de una cristalización parcial en forma de cristobalita. Esta estructura fue producida controlando el agente catalítico mencionado en el proceso de preparación. Los espectros de EPR y absorción UV-Vis muestran la presencia de iones Fe3+ como un contaminante proveniente de las partículas de Ag, debido al proceso en el que fueron obtenidas las partículas. Por medio de espectroscopía IR se observo que en el sistema hay una alta concentración de (OH-) a temperaturas altas, hasta 600 ºC a diferencia de los vidrios producidos por sol-gel con la incorporación de partículas de Ag en forma de nitratos. La evolución del color en muestras con el recubrimiento con el tratamiento térmico varía de café ligero a 100 ºC hasta amarillo a 500 ºC