Carbon fibre-reinforced polymers (CFRPs) are commonly used in aviation, automotive and renewable energy markets, which are constantly growing. Increasing the production of composite parts leads to increased waste production and a future increase in end-of-life components. To improve the recyclability of CFRPs, new materials that fit in with the idea of a circular economy should be used as a composite matrix. One such material is a commercially available thermoplastic liquid resin, Elium® (Arkema, France). In this work, the authors investigated how the mechanical recycling process affects the properties of thermoplastic-based carbon fibre composites. CFRPs with neat Elium® resin and resin modified with 0.02 wt.% single-walled carbon nanotubes or 0.02 wt.% multi-walled carbon nanotubes were manufactured using the resin infusion process. Afterwards, prepared laminates were mechanically ground, and a new set of composites was manufactured by thermopressing. The microstructure, mechanical, thermal and electrical properties were investigated for both sets of composites. The results showed that mechanical grinding and thermopressing processes lead to a significant increase in the electrical conductivity of composites. Additionally, a sharp decrease in all mechanical properties was observed.

In this study, the effect of rhenium addition (2, 4, and 6 wt pct) and building orientation (0 and 90 deg) on the microstructure and corrosion resistance of Inconel 718 (IN718) alloy processed by selective laser melting (SLM) was investigated. Microstructure characterization showed that the as-built IN718-Re alloys consist of columnar grains growing parallel to the building direction (Z-axis). Each columnar grain was characterized by a fine columnar/cellular dendritic substructure with Nb- and Mo-rich Laves phases and MC-type carbides embedded in the interdendritic spaces. Rhenium addition segregated to γ phase dendrites which resulted in an increase of the columnar/cellular substructures width with increasing Re content. Due to a strong microstructure anisotropy of SLM-processed IN718-Re alloys, the corrosion properties were examined for mutually perpendicular planes: XY (90 deg samples) and XZ (0 deg). The presence of rhenium enhanced the corrosion resistance of IN718 alloy in 0.1 M Na₂SO₄and NaCl solutions at both exposed planes. The corrosion current density was significantly reduced for IN718-Re alloys and increasing Re content correlated with a more positive shift in corrosion potential. Moreover, the XY plane possessed better corrosion resistance than the XZ plane due to the higher fraction of laser overlapping areas observed for the XZ plane.

The aim of this research was to improve the electrical and mechanical properties of carbon-fibre-reinforced polymers (CFRP) based on thermoplastic acrylic resin ELIUM^®, by introducing single-walled carbon nanotubes (SWCNTs) into their structure. The laminates were fabricated using the infusion technique of infiltrating the carbon fabric with the mixture of acrylic resin and SWCNTs. The addition of SWCNTs improved the electrical conductivity through the thickness of the laminate by several times compared to the laminate without modification. No defects or voids were observed in the structure of the fabricated nanocomposites. The introduction of SWCNTs into the CFRP structure increased the Young’s modulus, interlaminar shear strength and impact resistance. DMA analysis showed almost no change in the glass transition temperature of the fabricated SWCNT/CFRP nanocomposites compared to the reference laminate.

The article presents the results of research on the influence of plastic deformation on the microstructure and tensile strength of Haynes 282 nickel superalloy produced by direct metal laser sintering (DMLS) and a conventional technique (casting). Samples were tested for dimensional accuracy using a 3D scanner. Then, the samples were subjected to plastic deformation by rolling. The microstructures of the DMLS and the as-cast samples were analysed using a scanning electron microscope. The strength properties of the samples were determined in a static tensile test. Microhardness measurements of the samples were also performed. Based on the analysis of the dimensional accuracy, it was found that the surface quality of the components produced by DMLS is dependent on the input parameters of the 3D printing process. Using the DMLS method, it is possible to produce Haynes 282 with a fine-crystalline microstructure containing dendrites. The fine-crystalline dendritic microstructure and low porosity showed very good tensile strength compared to the as-cast material. It was also found that the increase in the degree of plastic deformation of the as-cast Haynes 282 and the samples produced by the DMLS technique resulted in an increase in the strength of the tested samples, with reduced ductility.