Acrylonitrile‐butadiene‐styrene (ABS) based composites with a high content of tungsten and bismuth oxide were developed using an innovative process to obtain lead‐free x‐ray shielding materials. ABS was chosen for its good mechanical properties and its widespread availability as a recycled material. The composites underwent flexural tests, Shore D hardness tests, thermogravimetric and morphological analysis, and their x‐ray attenuation properties were determined through numerical simulations and experimental measurements. Despite their high filler content (up to 75 wt%), the composites showed good filler dispersion within the polymeric matrix and maintained their mechanical properties. Across the investigated energy range (50–150 kV), the lead equivalence for x‐ray shielding was achieved with composite plates containing 75 wt% of tungsten and bismuth oxide, at thickness values corresponding to a weight increase of only 29% and 36%, respectively, in comparison to lead. These findings pave the way for a new generation of lead‐free x‐ray shielding materials. Moreover, their mechanical properties, including flexibility for potential application in wearable personal protective equipment, can be tailored by adjusting the filler content.Highlights: High filler content lead‐free ABS composites with WO₃ and Bi₂O₃ were developed. They show good polymer/filler interfacial adhesion and flexural properties. Numerical simulations of their x‐ray shielding properties were performed. Experimental tests with polychromatic sources confirmed good x‐ray attenuation. Results pave the way for the development of new lead‐free x‐ray shielding systems.

Advanced polymeric foams with enhanced thermal insulation and mechanical properties are used in a wide range of industrial applications. The properties of a foam strongly depend upon its cell structure. Traditionally, their microstructure has been studied using 2D imaging systems based on optical or electron microscopy, with the obvious disadvantage that only the surface of the sample can be analysed. To overcome this shortcoming, the adoption of X-ray micro-tomography imaging is here suggested to allow for a complete 3D, non-destructive analysis of advanced polymeric foams. Unlike metallic foams, the resolution of the reconstructed structural features is hampered by the low contrast in the images due to weak X-ray absorption in the polymer. In this work an advanced methodology based on high-resolution and low-contrast techniques is used to perform quantitative analyses on both closed and open cells foams. Local structural features of individual cells such as equivalent diameter, sphericity, anisotropy and orientation are statistically evaluated. In addition, thickness and length of the struts are determined, underlining the key role played by the achieved resolution. In perspective, the quantitative description of these structural features will be used to evaluate the results of in situ mechanical and thermal test on foam samples.

Selective Laser Melting (SLM) is an attractive Additive Manufacturing (AM) technology for the fabrication of metallic components with complex structures and high performances. This process fulfills the goals of sustainable production by reducing material waste, optimizing product topology, and recycling metallic powder. Aluminum alloys exhibit also sustainable performances being lightweight and recyclable. Al-Si10-Mg alloy is suitable for SLM processing due to its good castability, good strength, wear, and corrosion resistance. However, the laser processing of aluminum alloys to date needs to be optimized. In this study, the authors have analyzed the role of close values of heat input on microstructure and defects (Electron and Optical microscope, DRX analysis), porosity (optical microscope and X-ray tomography), melting pool geometries (both in transversal and longitudinal sections of the samples) and mechanical performance (hardness and tensile test) of Al-Si10-Mg samples. The results have shown that even at very close values of energy density, the microstructure and properties of the samples differ from each other.