The slurry aluminizing process is widely employed to enhance the oxidation and corrosion resistance of nickel-based superalloys used in high-temperature environments such as gas turbines and aerospace engines. This study investigates the effects of the concentration of Al vapors in the reactor chamber and the initial slurry layer thickness on the microstructure, chemical composition, and phase composition of aluminide coatings. Coatings were manufactured on Ni-based superalloy substrates using CrAl powders as an aluminum source and chloride- and fluoride-based activator salts. The effect of the initial thickness of the slurry layer was studied by varying the amount of deposited slurry in terms of mg_slurry/cm²_sample (with constant mg_slurry/cm³_chamber). The microstructure and phase composition of the produced aluminide coatings were evaluated by SEM, EDS, and XRD analysis. Slurry thickness can affect concentration gradients during diffusion, and the best results were obtained with an initial slurry amount of 100 mg_slurry/cm²_sample. The effect of the Al vapor phase in the reaction chamber was then investigated by varying the mg_slurry/cm³_chamber ratio while keeping the slurry layer thickness constant at 100 mg_slurry/cm²_sample. This parameter influences the amount of Al at the substrate surface before the onset of solid-state diffusion, and the best results were obtained for a 6.50 mg_slurry/cm³_chamber ratio with the formation of 80 µm coatings (excluding the interdiffusion zone) with a β-NiAl phase throughout the thickness. To validate process flexibility, the same parameters were successfully applied to produce platinum-modified aluminides with a bi-phasic ζ-PtAl2 and β-(Ni,Pt)Al microstructure.

Ecosystems and environments are impacted by atmospheric pollution, which has significant effects on human health and climate. For these reasons, devices for developing portable and low-cost monitoring systems are required to assess human exposure during daily life. In the last decade, the advancements of 3D printing technology have pushed researchers to exploit, in different fields of applications, the advantages offered, such as rapid prototyping and low-cost replication of complex sample treatment devices. In this work, we present the fabrication and testing of 3D printed cartridges based on both commercial photopolymer and a modified version with the intrusion of nano graphite. The air scrubbing performances towards some volatile organic compounds have been investigated, inserting the cartridges into a low-cost monitoring system using a photoionization sensor. In particular, the cartridges were tested in the presence of concentrations of ethanol, benzene, and toluene to evaluate the abatement percentage with and without their use. Although the results have shown that all cartridges abated ethanol and toluene, the abatement of benzene increased 20 times in the case of cartridges based on modified resin with nano graphite. These results could enable their employment to reduce the concentration of interfering compounds in low-cost monitoring systems.

Electrically conductive photopolymers enable the fabrication of functional 3D-printed components with customized electrical properties, expanding additive manufacturing applications beyond traditional structural uses. This study reports the formulation and characterization of electrically conductive, water-washable photopolymer resins for masked stereolithography (MSLA) through the incorporation of nano-graphite, PEDOT:PSS, and dimethyl sulfoxide (DMSO) as a secondary dopant. Single filler and hybrid resin systems were prepared and processed via MSLA printing, then subjected to sequential thermal treatments, 25 °C curing for 48 h followed by annealing at 80 °C and 120 °C, to investigate conductivity enhancement and microstructural evolution. Electrical characterization via current–voltage (I–V) measurements, referenced to the transversal conductivity (${\sigma }_{TRA}$), showed that the hybrid formulation containing PEDOT:PSS, graphite, and DMSO achieved the highest conductivity (9.40 × 10⁻² S·cm⁻¹), outperforming PEDOT:PSS/graphite systems (2.6 × 10⁻³ S·cm⁻¹) and graphite-only samples (9.76 × 10⁻⁴ S·cm⁻¹). Conductivity increased consistently after each thermal step, indicating enhanced charge transport. Scanning electron microscopy further revealed improved filler dispersion and interconnectivity within the polymer matrix. The synergistic combination of PEDOT:PSS, graphite nanofillers, and DMSO enables MSLA printed components with tunable and reproducible electrical performance. This work demonstrates a scalable strategy for producing functional, water-washable photopolymer resins suitable for applications in sensors, soft electronics, and lightweight conductive structures.