Carbon fiber reinforced polymers (CFRP) are widely recognized for their exceptional strength-to weight ratio, making them ideal for advanced applications requiring superior mechanical performance and low weight. However, their heterogeneous composition poses challenges in both processing and surface treatment, which are crucial to improve the strength of bonded joints involving CFRP adherends. Laser processing technology offers several advantages in the processing of CFRPs, such as the effective removal of contaminants (e.g. mold release compounds) which hamper adhesion to structural adhesives. In this work, a UV picosecond laser is used to perform surface preparation of CFRP compression molding laminates. The proposed treatment not only cleans the matrix of release agents but also enables selective matrix removal without damaging the carbon fibers. Pre- and post-treatment surface morphology and chemistry are analyzed using a stereomicroscope, a digital microscope, a scanning electron microscope, and X-ray spectroscopy. The results are an improvement in the ultimate tensile strength of CFRP/CFRP single lap joints by more than 300% compared to the baseline untreated material. Furthermore, the fracture mode for laser-treated samples changes from adhesive to cohesive/fiber tearing, since the adhesive penetrates between the bare fibers.

Composite structures are increasingly being used across various industries to promote structural lightweighting but also because of their excellent fatigue and corrosion resistance. To further minimize weight while preserving these benefits, adhesive bonding is now widely used to join advanced composite materials. However, effective surface pretreatments are essential to ensure suitable joint mechanical properties, including strength, fracture toughness, and long-term durability. The present study investigates viable surface preparation methods for a carbon fiber reinforced composite obtained through compression molding. Both standard mechanical abrasion and advanced ultrashort UV-laser treatment were evaluated. The effect of surface modification on surface morphology was evaluated using Scanning Electron Microscopy (SEM), while the corresponding modification of surface chemistry was determined using Energy Dispersive X-ray Spectroscopy (EDS). The combined results allowed us to judge the ability of the proposed strategies to modify surface morphology and remove post-processing contamination, primarily silicon-based. Besides, displacement-controlled tensile tests were conducted on adhesive-bonded single-lap joints to assess joint strength. The results show that UV laser ablation effectively removes contaminants on the matrix material without damaging the carbon fibers, improving adhesive joint shear strength compared to sanded specimens.

Machining of medium-carbon steels, such as AISI 1050, poses a significant challenge in terms of achieving stable cutting conditions, controlled chip evacuation and high surface integrity, in particular when full-face milling is performed under elevated material removal rates. The tool surface engineering approach, particularly laser-induced micro-texturing, comprises a promising route toward modifying the tribological conditions at the tool–chip interface, thus affecting friction, heat generation, chip formation and the resultant surface finish. This study investigates the combined effects of cutting speed, axial depth of cut and tool micro-texture orientation (parallel versus orthogonal to the chip flow direction) on machining performance under wet conditions. In addition to the experimental analysis of cutting forces, chip morphology and surface roughness, this work integrates a full factorial Design of Experiments, regression modeling, and ANOVA to quantify the statistical significance of each factor and to identify dominant interactions. The regression models show strong predictive capability across all measured responses, while the ANOVA confirms the axial depth of cut and tool texture orientation as the most influential parameters. Multi-objective optimization by Pareto analysis further underlines the superiority of orthogonal micro-texturing, which consistently reduces the cutting forces and improves surface quality while promoting controlled chip segmentation. The results provide quantitative and statistically validated evidence of the enhancement of lubrication effectiveness, reduction in interface friction, and stabilization in chip formation provided by the micro-textured tools. Overall, the findings contribute to the development of data-driven machining strategies and surface-engineered cutting tools in view of improved productivity, energy efficiency and surface integrity in advanced manufacturing applications.

Laser surface microtexturing has emerged as an effective approach for improving the performance of adhesive joints between dissimilar materials. In this study, the influence of laser-generated micrometric surface features on the mechanical behavior of hybrid adhesive joints was investigated for two material systems: structural steel bonded to polyamide (PA66) and structural steel bonded to technical ceramic (Al₂O₃). Single-lap joints were manufactured using a two-component epoxy adhesive with two nominal bond-line thicknesses (0.1 mm and 1.0 mm). Prior to bonding, selected surfaces were modified by ultrashort-pulse laser microtexturing, producing well-defined circular features with characteristic depths on the order of tens of micrometers. The resulting microstructures were characterized using optical and scanning electron microscopy, and their geometric parameters were quantified through profilometric measurements. Mechanical performance was evaluated under shear and bending loading conditions. The results demonstrate a substantial increase in joint strength for laser-microtextured surfaces compared with non-textured references for both material combinations. The effect of surface microtexturing was more pronounced than the influence of adhesive layer thickness within the investigated range. These findings confirm that laser-induced surface microtexturing is a versatile and application-oriented surface preparation method capable of enhancing the reliability of adhesive bonding in hybrid metal–polymer and metal–ceramic assemblies.

In the injection molding process, handling shrinkage is crucial to reduce warpage in molded parts. As demand increases for complex components with high-quality standards, including tight tolerances and defect-free parts, numerical tools have become essential for optimizing the process and improving product performance. This work proposes a novel method to accurately predict part warpage using the Anisotropic Thermo-Viscous Elastic Residual Stress Model implemented in Moldflow, with a focus on calibrating numerical simulations through manual adjustment of the Coefficients of Linear Thermal Expansion (CLTE). Using optical 3D scanning acquisitions to compare experimental results with simulation predictions, the method enables precise calibration that reduces numerical-experimental discrepancies in warpage predictions.