Dynamic mechanical analysis (DMA) is an important method for evaluating the viscoelastic properties of polymeric materials, especially when investigating their mechanical response to various manufacturing parameters and surface treatments. In recent years, DMA analysis has been intensively used, among others, for the analysis of polylactide (PLA) produced by the fused filament fabrication (FFF) additive technology. The present study focuses on the effect of DCSBD plasma treatment on the dynamic-mechanical properties of PLA samples with different infill geometries (Line, Rectilinear and Concentric). In the study, experimental PLA samples were subjected to DMA analysis in the temperature range of 40 C to 90 C in order to analyze the changes in their viscoelastic properties after plasma discharge surface treatment. The results showed a decrease in the glass transition temperature (Tg) for all tested samples, while the extent of the decrease depended on the infill geometry used. The most significant changes were observed in samples with Rectilinear infill, which showed the best mechanical stability after plasma treatment. The study shows that plasma treatment can influence the mechanical properties of PLA products, opening new possibilities for optimizing their processing, reuse and application in technical areas requiring controlled mechanical response.

Geometric deviations play a crucial role in the quality of additive manufacturing, particularly in parts made with biodegradable resins. Accurately controlling dimensional and geometric variations in manufactured components is critical for achieving defect-free production and meeting functional standards. However, defining a final quality score can be challenging due to numerous dimensional and geometric deviations associated with a part. An innovative metric for evaluating geometric performance was created to measure dimensional precision in components produced through VAT photopolymerization. The index measures the dimensional and geometrical deviations, revealing that external surfaces exhibit greater precision than internal ones. This difference is likely due to internal surfaces overcoming heat dissipation challenges during the cooling process, resulting in less shrinkage for external surfaces. This index is essential in various stages of the manufacturing process, including part design, design for manufacturing and assembly, quality assurance, and process planning, helping to select the appropriate additive manufacturing technology and optimal process parameters.

Polymers and their surface modifications are the subject of intensive research due to their wide industrial applications in the fields of food packaging, biomedicine and electronics. The most widely used polymer films include polyethylene (PE), polyethylene terephthalate (PET) and polypropylene (PP), whose surface and mechanical properties can be optimized through physicochemical modifications. Diffuse coplanar surface barrier discharge (DCSBD) represents an effective method for modifying the surface properties of polymers without significantly affecting their structural properties. This study focuses on analyzing the effect of DCSBD plasma discharge on the mechanical behavior of PE, PET and PP films by means of dynamic mechanical analysis (DMA). Experimental samples were exposed to DCSBD plasma discharge and subsequently subjected to DMA over a wide temperature range. The measurement results showed significant changes in the storage modulus (E′), loss modulus (E′′) and loss angle (tan δ), while a decrease in material stiffness and a shift in glass transition temperatures (Tg) were identified.

Engineering polymers like PMMA have increasingly replaced traditional materials where feasible, with CO 2 laser cutting gaining attention for its high quality and speed in processing these materials. Precise cuts are essential for product accuracy, with kerf width being a key quality attribute for ensuring the final product's quality. This study focuses on the impact of three process variables: stand-off distance, laser power, and cutting speed, on the kerf width in CO 2 laser cutting of PMMA. A full-factorial experiment systematically varies process parameters to understand their individual and interaction effects on the cutting process. The kerf width is measured as an indicator of precision to evaluate the quality of the laser cuts. In order to address the non-linear relationships between these process parameters and kerf width, several machine learning models were utilized. Performance comparisons indicated that the Artificial Neural Network (ANN) model provided the highest accuracy, with R² values of 0.98 for the validation dataset and 0.95 for the testing dataset. The optimized ANN model is a robust tool for parameter optimization, determining optimal settings to achieve the desired kerf width and ensure productivity.

The aim of the research was to assess the influence of additions of different proportions of alumini-um waste chips from the machining technology on the melt quality and final properties of AlSi7Mg0.3 alloy casts. All casts were created using by gravity casting technology into preheated metal mold. The first cast was a pure AlSi7Mg0.3 alloy, followed by other samples with contents of 10, 30, 50, 70 wt.% of aluminum waste chips in the batches. All the samples were subjected to the Brinnel hardness and Vickers microhardness of solid solution of α(Al). Also, Density index was measured. At the end of research, the microstructures of the samples were analyzed using a Laser Confocal Microscope Olympus Lext OLS 5000.

The article is focused on the analysis of the additive technology (3D printing) applicability by using DMLS in the production of the reducing valve part, i.e. atmospheric resistor. Currently, the men-tioned part is produced by EDM in combination with soldering from the Inconel 718 steel. The use of additive technologies brings the assumption of greater flexibility and economy of production, which is verified by a set of analyzes focused on the accuracy of production and the utility properties of the mentioned part. In addition to technological aspects, such as individual production processes, economic aspects are also compared. Individual comparisons are the basis for assessing whether replacing the conventional production approach with 3D printing is advantageous in this case. The results of this assessment can subsequently be used for future applications of the considered additive manufacturing approaches in the case of similar components.

To increase the service life of the cutting tool, various types of coatings are used in modern times, which have a beneficial effect on extending the service life of the tools. Which contributes to reducing the eco-nomic costs of production. The present article examines the effect of cutting speed on the durability of a cutting tool. In the experimental measurements, three types of replaceable cutting inserts were used, without coating, with TiC and TiN coating. The measurements were carried out during technological operations of longitudinal turning on bearing steel 100CrMn6 without the use of coolant. The durability of the cutting discs was evaluated by the method of short-term tests, in which the main evaluation crite-rion was the amount of wear on the back surface of the cutting tool VBBcrit = 0.25 mm. For the statistical processing of the measured results, a detailed mathematical calculation was performed using the meth-od of least squares to determine the parameters of the linear regression function.

Additive technologies are becoming a common part of not only prototype production, but also piece or small series production. However, the choice of technology and material plays a key role in the applicability of the manufactured parts. The most widespread type of additive technology is FFF technology, which consists of applying a fused plastic string in single layers. The resulting mechanical properties of parts produced using this technology depend not only on the material and structure selected, but also on the process parameters used in the printing process itself. This study deals with the production of filament from PLA, which is the primary material. The advantage is its environmental degradability after the end of the life cycle of PLA products. However, the resulting properties of the printed parts may depend on the way the filament is prepared and in particular on the melt temperature during filament extrusion. This study investigates the effect of the produced filaments on the quality of printed parts. It has been shown that the filament production technology has a significant effect on the quality of printed parts.

The friction stir welding (FSW) method is classified as a so-called green or eco-friendly production technology in terms of its environmental impact. In the process of friction stir welding, there is no melting and the weld joint is formed by the movement of a rotating tool between the materials to be welded. The advantage of this technology is welding without the accompanying phenomena such as the release of harmful substances into the air, the emission of infrared, ultraviolet and visible radia-tion, and low energy consumption. In this work, friction stir welding tests of FSW and SR-FSW type were carried out, the butt welds themselves were performed on EN AW - 6060 sheets of 5 mm thick-ness. The surfaces of the specimens that met the weld quality visually were treated with laser shock peening (LSP), which is based on a pulsed effect. In the process of experiments, the authors investi-gated the weld quality at different speeds and tool rotation visually, then the welds were subjected to microscopic analysis, microhardness analysis and nanohardness analysis.

Aiming at obtaining ultra-low kinematic stiffness and improving the isolation property of low frequency vibration, it is necessary to solve the coupling parameters and rated load of air negative pressure characteristics and rubber characteristics, in order to achieve an ideal elastic characteristic curve of air negative pressure spring. Firstly, the background and working principle of the negative pressure rubber isolation were introduced. In addition, the FEA model of isolator is built based on Mooney-Rivlin constitutive model of rubber. Furthermore, to testify the validity of the mathematical model, the static characteristic and simulation analysis of isolator are studied. The experimental data and characteristic curve of different negative pressure were obtained, the simulated results show a good agreement with those of corresponding experiments. Finally, they also illustrate the validity of the vibration isolation, which realizes better performance of low-frequency vibration isolation.