Solid State Phenomena Vol. 391

Abstract: This study examines the fabrication and performance of hydrophobic copper and nickel foams produced via a two-step immersion coating method using silver nitrate and stearic acid, targeting oil–water separation and corrosion protection in marine-related environments. In both substrates, silver deposition generated hierarchical surface roughness, while stearic acid functionalization reduced surface energy. Surface morphology and coating integrity were analyzed using scanning electron microscopy (SEM), and wettability was evaluated through water contact angle measurements. Copper foams exhibited water contact angles approaching 180°, demonstrated improved coating adhesion and separation efficiency remained above 95 % over repeated use. Copper-based superhydrophobic foams also showed excellent thermal and chemical stability, maintaining hydrophobicity after prolonged exposure to harsh conditions. Nickel foams developed a strongly adhered hydrophobic silver coating with water contact angles of approximately 147°. The coatings maintained high hydrophobicity across a wide temperature range and exhibited excellent reusability, achieving oil–water separation efficiencies higher than 95 % after multiple cycles. Potentiodynamic polarization was employed to evaluate corrosion behavior of both coated substrates in 3.5 % NaCl solution. Overall, the results indicate that while the same coating effectively provides hydrophobicity and durability to both copper and nickel foams, differences in wettability and coating stability are determined by their intrinsic microstructures.

Abstract: During dry fibre processing, manufacturing geometrically complex composite parts often produces wrinkles when fabrics deform beyond their shear limits. This work proposes a design-for-manufacture approach based on origami principles, which modifies component geometry so that deformation remains within allowable deformation limits. A baseline aircraft spar geometry is considered; an origami-inspired version, along with several intermediate designs between these two extremes, are generated. Preliminary forming trials with unidirectional non-crimp fabrics show that the origami-based geometry is inherently manufacturable without defects, and that a selected intermediate design also form successfully, confirming a larger manufacturable design space than classical origami permits. Results further show that wrinkle severity increases with increasing angular defect. This provides a foundation for linking geometric measures to draping mechanics to guide the design of wrinkle-free composite components without requiring computationally expensive simulations.

Abstract: Although Laser engraving (LE) is increasingly adopted for precision surface texturing, the resulting surface is highly sensitive to the coupled thermal and hydrodynamic mechanisms governing laser–material interaction. In this experimental work, LE of Incoloy 800HT is systematically investigated using an L9 Taguchi design of experiments considering Laser Power (LP), Laser Scanning Speed (LSS), and Laser Pulse Frequency (LPF) as control parameters. Surface roughness is quantified using the arithmetical mean height (Ra), maximum profile height (Rz), skewness (Rsk), and the height at material ratio Rmc = 20%, enabling both amplitude-and function-oriented assessment of the engraved textures. The contribution of each parameter is evaluated through ANOVA and response ranking, and regression-based correlations are established to support predictive selection of processing conditions. The results show that LP is the dominant factor for Ra, Rz, and Rmc (20%), while LSS primarily governs Rsk, reflecting the role of scanning speed in controlling melt redistribution and peak–valley balance. High cumulative energy conditions promote thermal accumulation, melt ejection, spatter redeposition, and recast formation, leading to substantially rougher surfaces, as corroborated by topography and SEM observations.

Abstract: Some parts made of polymeric materials are used in abrasive environments. Any damage to their integrity by abrasive environments could have a negative effect on the operation of those parts. In the paper, it is proposed to use a process and equipment for evaluating the resistance to abrasive erosion based on the application of a process of enlarging a previously made hole in the polymer material specimen using a conical abrasive tool. The feed movement of the conical abrasive tool takes place under the action of a counterweight of known size. The duration of the process of enlarging by abrasion provides information on the resistance to abrasive erosion of the specimen material. An experimental study of the resistance to abrasive erosion of a polymeric material using the enlarging process with a conical abrasive tool was designed and implemented. The experimental results were processed mathematically, and an empirical mathematical model was obtained that highlights the influence of some input factors in the abrasive process on the resistance to abrasive erosion evaluated through the duration of the enlarging process with a conical abrasive tool. The possibility of using enlarging by abrasion as a procedure for evaluating the resistance to abrasive erosion was confirmed.

Abstract: The increasing use of fibre-reinforced composites raises critical issues related to sustainability and end-of-life management, particularly for thermoset-based systems. In this work, a non-conventional thermo-mechanical recycling strategy is proposed for hemp/carbon hybrid laminates, aiming at the recovery and reuse of intact reinforcement plies without destructive fibre-matrix separation. Full carbon, full hemp, and two hybrid laminate configurations with different stacking sequences were manufactured, recycled through controlled thermo-mechanical disassembly, and reprocessed into new laminates. The flexural and interlaminar shear behaviour of virgin and recycled materials was investigated to assess the influence of the recycling process on mechanical performance.